Solar Energy for World Peace

Organized by

PROGRAMME AND ABSTRACTS

This conference is under the auspices of the Presidency of the Republic of Turkey

World PeaceSolar Energy for

August 17-19, 2013Istanbul / Turkey

w w w . s o l a r 4 p e a c e . o r g

VAKSIS R&D AND ENGINEERINGBilkent University Main Campus

Cyberplaza, B-220 Bilkent 06800 ANKARA-TURKEY

Phone: +90 312 265 0146 Fax: +90 312 265 0147e-mail: [email protected]

wwwww.vaksis.com

WELCOME TO THE INTERNATIONAL CONFERENCE ON “Solar Energy for World Peace” which will take place in Istanbul Convention Center on the dates of 17-18-19 of August 2013.

Decorated with most prominent scientists (among them two nobel prize colleagues) working in the field of solar energy problems, materials and devices, this international meeting will bring the experts together with the scientists of the world, especially from Asia, Middle East, North Africa and Sub Saharan Africa, where energy autonomy is of crucial importance for future peace and democracy.

As much as nuclear energy and fossil fuels are associated with catastrophes, wars and power politics, as much solar energy is correlated with a peaceful, clean and sustainable future. Human society needs decentralized solar energy for realization of global democratization via energy autonomy.

With this motivation in mind, the conference will be scientific and technical. No political talks will be scheduled except possible opening statements. If outstanding scientists exchange knowledge and ideas on “how to utilize solar energy on our planet” we can move things in a positive direction.

We are looking to welcome you in this exciting and beautiful conference and venue.

Niyazi Serdar SariciftciConference Chairman

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PLENARY / INVITED SPEAKERS

Bülent BasolDavid CahenHalil Ibrahim DagJames DurrantEitan EhrenfreundDavid FaimanDavid GinleyÖzer GöktepeSerap GünesWolfgang HeissAndrew HolmesArved HüblerOlle InganäsRene JanssenBruno JousselmeHorst KischFigen KadirganVictor I. KlimovKarl LeoYongfang LiEfrat Lifshitz

Maria-Antonietta LoiKoushik MajhiDaniel MosesJenny NelsonDavid Leslie OfficerReinhold PriewasserJean RoncaliIfor D.W.SamuelMykhailo SytnykUlrich ScherfHans Werner SchockChing TangTomas TorresHarun TüysüzTanay Sidki UyarFred WudlPeter WürfelShozo YanagidaTsukasa YoshidaAnvar ZakhidovIzeddine Zorkani

PLENARY SPEAKERSWalter Kohn (Nobel Prize in Chemistry 1998)Alan J. Heeger (Nobel Prize in Chemistry 2000)Martin GreenDaniel NoceraJürgen ScheffranMichael GrätzelMichele ArestaJohn Perlin

INVITED SPEAKERS

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INTERNATIONAL ADVISORY BOARD

Professor Tareq Abu HamedDirector of Center for Renewable EnergyThe Arava Institute for Environmental StudiesIsraelwww.arava.org

Professor Sabry Abdel-MottalebProfessor of Chemistry, Principal InvestigatorNanoPhotochemistry and Solar Chemistry Labwww.photoenergy.org/photoenergyDepartment of Chemistry, Faculty of ScienceAin Shams University, 11566 Abbassia, Cairo, Egypt

Professor David CahenWeizmann Institute of ScienceRehovot, Israel

Professor Helmut DoschDeutsches Elektronen Synchrotron (DESY)Vorsitzender des DirektoriumsNotkestr. 85D-22607 Hamburg, Germany

Doz. Dr. Daniel Ayuk Mbi EgbeLinz Institute for Organic Solar CellsJohannes Kepler UniversityLinz, AustriaSecr. Gen. of ANSOLE,African Network of Solar Energywww.ansole.org

Professor Can ErkeyDepartment of Chemical andBiological EngineeringKoc University34450 SariyerIstanbulTURKEY

Professor David FaimanSolar Energy Center Sede BoqerBen Gurion University of NegevIsrael

Professor Andrew B. HolmesMelbourne Laureate Professor and CSIRO FellowBio21 Institute, University of MelbourneBuilding 102 (Level 4)30 Flemington RoadParkville, Vic 3010Australia

Professor Figen KadirganDepartment of ChemistryIstanbul Technical UniversityMaslak, IstanbulTurkey

Professor Walter KohnDepartment of PhyiscsUniversity of CaliforniaSanta Barbara, CA 93106USA

Professor Reinhold LangInstitute of Polymeric Materials and TestingJohannes Kepler UniversityLinz, Austria

Professor Zafra LermanPresident of the Foundation forMalta Conferences for Science and PeaceChicago, USA

Professor Reghu MenonDepartment of PhysicsIndian Institute of ScienceBangalore, INDIA

Professor Jean RoncaliResearch DirectorLinear Conjugated Systems Group, CNRS, Moltech-AnjouUniversity of Angers, 2 Bd Lavoisier, F-49045 AngersFrance

Professor Rasit TuranDepartment of PhysicsMiddle East Technical UniversityAnkara, Turkey

Professor Shozo YanagidaEmeritus ProfessorOsaka University, ISIR Hy-SOL CO., LTD8-1, Mihoga-oka, Ibaraki,Osaka, Japan

Professor Anvar ZakhidovNanoTech InstituteUniversity of Texas at DallasUSA

PROGRAMME

PROGRAMME

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Saturday, the 17th of August, 2013

08:00- RegistrationHALL 1

09:00-09:05 Welcome by Niyazi Serdar Sariciftci09:05-09:20 Opening Statement “A World Powered Predominantly by Solar and Wind

Energy” by Walter Kohn (Nobel Prize 1998)09:20-09:30 Opening Statement by Abdullah Gül (President of Turkey)

09:30-09:45 Coffee Break

09:45-10:15 Plenary Lecture: "Silicon Solar Photovoltaics: Changing the World" by Martin Green10:15-10.45 Plenary Lecture: "Personalized Energy (for Everyone) Enabled by the Artificial Leaf"

by Daniel Nocera

10:45-11:10 Coffee BreakHALL 1 HALL 2

Photovoltaic Materials IChairman: Anvar Zakhidov

Solar Heat ConversionChairman: Helmut Neugebauer

11:10-11:30 Invited lecture: "Prospects of Chalcopyrite-Based Thin Film Solar Cells: Towards Competitive

Efficiencies" by Hans Werner Schock

Invited lecture: “Nanocoated Selective Absorber

Surfaces”by Figen Kadirgan

11:30-11:45 “Electrochemical Deposition of ZnO Columnar Arrays”

by Vlad Andrei Antohe

“Fresh Water Production and Phase Change Materials”

by Ravishankar Sathyamurthy11:45-12:00 “NIR Plasmonics of Metal Doped ZnO

Derivatives”by Arrigo Calzolari

“Composite Absorber Solar Collectors”by Alfa Oumar Dissa

12:00-12:20 Invited Lecture:“Carrier Multiplication in Semiconductor

Nanocrystals”by Victor Klimov

Invited Lecture:“Fabrication of Photovoltaic/Thermal

(PV-T) Hybrid Collectors of SOLIMPEKS”by Halil Ibrahim Dag

12:20- 13:30 LUNCH (Lunchbox)HALL 1 HALL 2

Photovoltaic Materials IIChairman: Victor Klimov

Synthesis of Materials IChairman: Fred Wudl

13:30-13:50 Invited lecture: “Hybrid Tandem Solar Cells Tunable by

Ionic Charging” by Anvar Zakhidov

Invited lecture: “2D Conjugated Polymers for Polymer

Solar Cells “by Yongfang Li

13:50-14:05 “Efficiency Limits of Bulk Heterojunction Solar Cells”

by Markus Clark Scharber

“D-A-D Polymers for Polymer Solar Cells”by Xiabin Peng

14:05-14:20 “ZnO Nanorod and Extremely Thin CIS Solar Cells by Spray Coating”

by Erki Kärber

“Medium Band Gap Polymers with Benzo-Dithiophenes”

by Desta Antenehe Gedefaw

PROGRAMME

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Saturday, the 17th of August, 2013

14:20-14:40 Invited Lecture:“Thin Film Polycrystalline Compound PV Technologies: Status and Future

Prospects”by Bülent Basol

Invited Lecture:“Synthesis as a Key Tool in the

Development of Materials for Organic Electronics”

by Ulrich Scherf


Photovoltaic Materials IIIChairman: Peter Würfel

Surveys and ExamplesChairman: Sabry Abdel Mottaleb

15:00-15:20 Invited lecture: “Low Resistance Back Contact Buffers for

CdS/CdTe Cells” by Ching W Tang

“Integrated Solar Combined Power Plant for Turkey”

by Ahmet Emin Sentürk

15:20-15:35 “Quantum Dots for Solar Cells” by Sihem Jaziri

“Renewable Energy in Malawi”by Esther Phiri

15:35-15:50 “Enhanced Stability of PV Devices by Addition of Nanoparticles”

by Emmanuel Kymakis

“African Network for Solar Energy (ANSOLE): Bridging Africans in Capacity Building and Use of Sustainable Energy

Sources and Technologies” by Daniel Ayuk Mbi Egbe

15:50-16:05 “Nanocomposites of N-Doped TiO2/CdS for DSSC “

by Cahyorini Kusumawardani

“Photovoltaics in Chad”by Yacoub Idriss Halawlaw

16:05-16:20 “Effect of Deposition Temperature of CdS Films on Inverted Solar Cells”

by Gülbeden Cakmak

“Solar Energy R&D Landscape and Solar Energy Roadmap of South Africa”

by Malik Maaza16:20-16:35 “SWNT Doped Titania for DSSC”

by Giampiero Ruani“Solar Cooker Integrated with Nano Composite Phase Change Materials”

by Eswaramoothy Muthusamy16:35-16:50 “Kesterite Based Solar Cells by

Electrodeposition-Selenization”by Diego Colombara

“Improving the Sustainibility of Solar Thermal Electric Systems”

by Roman Adinberg16:50-17:10 Invited Lecture:

“Inorganic Nanostructures for Organic Solar Cells”

by Tsukasa Yoshida

Invited Lecture:“Solar Energy for Developing Countries:

Case Morocco”by Izeddine Zorkani

17:10-17:30 Invited Lecture:“Solar Electricity Generated and Stored

with Organic Materials”by Olle Inganäs

Invited Lecture:“Global Problems Require Collaborative

Solutions”by David Faiman

HALL 117:30-18:30 Panel Discussion “Solar Energy and Development in Africa”

Moderator: Daniel Egbe (ANSOLE)Podium: Samir Rhomdane (Tunis), Izeddine Zorkani (Morocco), Amel Benfredj (Tunis), Yohannes Teketel (Ethiophia), Malik Maaza (South Africa), Abdelfettah Barhdadi (Morocco).

18:30-20:30 Poster Session (Drinks, Snacks)

PROGRAMME

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Sunday, the 18th of August, 2013

HALL 108:00-08:30 Plenary Lecture: “Heisenberg Uncertainty Principle in Bulk Heterojunction Solar

Cells” by Alan Heeger (Nobel Prize 2000)08:30-09:00 Plenary Lecture: “Peace and Security in Renewable Energy Transformation”

by Jürgen Scheffran


Photonics and Spectroscopy IChairman: Tsukasa Yoshida

Synthesis of Materials IIChairman: Rene Janssen

09:30-09:50 Invited Lecture:“Tuning Electronic Properties of Colloidal

Nanostructures”by Efrat Lifshitz

Invited Lecture: “Very Low Bandgap Conjugated

Polymers”by Fred Wudl

09:50-10:10 Invited Lecture:“Exciton Diffusion, Charge Separation and Morphology in Polymer-Fullerene

Solar Cells”by Ifor D.W. Samuel

Invited Lecture:“ Design of Small Molecular Donors for

Organic Solar Cells”by Jean Roncali

10:10-10:25 Invited Lecture:“Magneto Photocurrent of Charge

Transfer Complexes” by Eitan Ehrenfreund

“Bulk Heterojunction Solar Cells using PPE-PPVs”

by Safae Aazou

10:25-10:40 “Electronics and Photonics two science in the benefit of solar energy conversion”

by Mihaela Girtan

“Doped Conjugated Polymers as Electrodes”

by Valerii Kobryanskii10:40-10:55 “Advanced EPR/Mössbauer Spectroscopy

of Bioinspired Complexes”by Özlen Erdem

“Hydrogen Bonded Conjugated Molecules”

by Eric Glowacki10:55-11:10 “Insights on the Interface in Polymer

Fullerene Solar Cells by Optical Sensing”by Stergios Logothetidis

“Isoindigo Based Polymers for Solar Cells”

by Ergang Wang11:10-11:25 “Effects of Ionizing Radiation on CdS/

CdTe Solar cells”by Stefan Antohe

“Bio-Inspired Light Harvesting System from Metallochlorins in Nanochannels”

by Kasim Ocakoglu11:25-11:40 “Inv. of Charge Carrier Recombination by

Intermodulation Spec.”by Wolfgang Tress

“Colloidal CuZnSnSe1-xSx Nanocrystal Based Hybrid Solar Cells “

by Mahmut Kus11:40-12:00 Invited Lecture:

“Developing an Artificial Photosynthetic Reaction Centre”

by David Leslie Officer

Invited Lecture:“Organic Nanocrystals from Latent

Pigments for Biocompatible Electronics”by Mykhailo Sytnyk

12:10- 13:30 LUNCH (Lunchbox)

PROGRAMME

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HALL 1 HALL 2Photovoltaic Materials and Devices I

Chairman: Giampiero RuaniSolar Fuels and Photochemistry I

Chairman: Markus Scharber13:00-13:20 Invited lecture:

“Carrier Relaxation Trough Localized States”

by Daniel Moses

Invited lecture: “Visible Light Semiconductor

Photocatalysis “by Horst Kisch

13:20-13:35 “Co-Evaporated OPV Based on Dyes and Fullerenes”

by Xiaofeng Wang

“Photoelectrochemical Reduction of CO2 on Organic Semiconductors”by Engelbert Portenkirchner

13:35-13:50 “Organic Photovoltaic Based on Squaraine Dye”

by Guo Chen

“CO2 Conversion to Solar Fuels with Microbial Electrolysis”by Anita Fuchsbauer

13:50-14:10 Invited Lecture:“ Inorganic, Organic and Hybrid Solar

Cells: How different are they? “ by David Cahen

Invited Lecture:“Solar Fuels: Breakthrough

Innovation in the Renewable Energy Industry”

by Reinhold Priewasser14:10-14:30 Invited Lecture:

“Oxide Absorbers for All Oxide Photovoltaics”

by Koushik Majhi

Invited Lecture:“Nanostructured Sodium Tantalum

Oxides for Solar Water Splitting”by Harun Tüysüz


Photovoltaic Materials and Devices II Chairman: David Ginley

Solar Fuels and Photochemistry IIChairman: Jean Roncali

15:00-15:20 Invited lecture: “Inverted Structure Hybrid Solar Cells”

by Serap Günes

Invited Lecture:“Towards highly efficient PbS nanocrystal

solar cells”by Maria-Antonietta Loi

15:20-15:35 “ Photodegradation Effects in Polymer/Fullerene

Solar Cells” by Tracey Clarke

“Electrocatalytic Assemblies for Water Splitting and Solar Fuels”by Khurram Saleem Joya

15:35-15:50 “Growing Silicon Nanowires with Ag Assisted Etching Method”

by Quertani Rachid

“Water Oxidation by Cobalt Oxide Nanoparticles”

by Karolina Kwapien15:50-16:05 “Measuring Mobilities and

Recombination in Organic Solar Cells”by Bronson Philippa

“CO2 Reduction with Immobilized Dehydrogenase Enzymes”

by Stefanie Schlager

16:05-16:20 “Ultrasonic Spray Pyrolysis of CIGS/InS Heterojunction Solar Cells”

by Erkan Aydin

“Treating Industrial Effluents by Solar Cells”

by Azam Pirkarami16:20-16:35 “CdS Nanostructured Layers in Solar

Cells”by Oleg Dimitriev

“ Water-soluble Chlorophyll Analogues for Artificial Photosynthesis”

by Kerstin Oppelt

PROGRAMME

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16:35-16:50 “Interfacial Degradation in Organic Solar Cells”

by Ayse Turak

“Performance of a 100 MW Solar Thermal Parabolic Trough Power Plant in

Cholistan Desert”by Muhammed Khurram Zafar

16:50-17:10 Invited Lecture:“Transient Photoresponse of PbS

Nanocrystals with Inorganic Ligands”by Wolfgang Heiss

Invited Lecture:“Direct Photosensitization of MoS3 by

Polymer/Fullerene BHJ Solar Cells”by Bruno Jousselme

17:10-17:30 Invited Lecture:“ Improved materials and device

architectures for polymer solar cells”by Rene A. J. Janssen

Invited Lecture:“Energy End Use Efficiency and 100%

Renewable Energy means Equality, Freedom, Peace, Democracy and Local

Employment” by Tanay Sidki Uyar

HALL 117:30-18:30 Panel Discussion “Solar Energy and Peace in the Middle East”

Moderator: Zafra LermanPodium: Walter Kohn, Niyazi Serdar Sariciftci, David Faiman, Sabry Abdel-Mottaleb, Tareq Abu Hamed, David Ginley.

19:30- 24:00 Conference Dinner on the Boat Cruise in Bosphorus (Bus transfer from Conference Center at 19:00)

PROGRAMME

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Monday, the 19th of August, 2013

HALL 109:00-09:30 Plenary Lecture: “Molecular Photovoltaics and Mesoscopic Solar Cells”

by Michael Grätzel09:30-10:00 Plenary Lecture: “Converting exhaust carbon into working carbon: from a linear- to

a cyclic-carbon-economy “ by Michele Aresta


Photovoltaic Materials and Devices IIIChairman: Wolfgang Heiss

General, Technology and SystemsChairman: Maria Antonietta Loi

10:30-10:50 Invited Lecture:“Molecular Solar Cells and MO

Interactions for Transport”by Shozo Yanagida

Invited Lecture: “Printed Solar Cells on Paper: A Paradigm

Shift”by Arved Hübler

10:50-11:10 Invited Lecture:“Organic Photovoltaics as Scalable

Sustainable Solar Technology”by David Ginley

Invited Lecture:“ Piezoelectric Enhancement of

Photovoltaic Efficiency “by James Durrant

11:10-11:25 “Wide Variety Metal Nanoparticles in Polymer Matrices for Solar Cells”

by Vladimir Astachov

“HCPV Grid Connected Power Plant for Research at the University”by Abdelfattah Barhdadi

11:25-11:40 “Charge Transport in Nanoporous Materials”

by Steven Konezny

“Techno Economic Investigation of Solar Water Heater Energy Saving System”by Mohammed Hamdan Al Smairan

11:40-12:00 Invited Lecture:“Small Molecular Organic Solar Cells”

by Karl Leo

Invited Lecture:“Developing Weavable Dye Sensitized Solar Cells on Carbon Nanotube Yarns”

by Özer Göktepe

12:00- 13:00 LUNCH (Lunchbox)HALL 1 HALL 2

Solar Energy Materials and Devices Chairman: Daniel Egbe

General Theory, Technology and SystemsChairman: Zafra Lerman

13:00-13:20 Invited lecture: “Challenges in Printing Organic Solar Cells”

by Andrew Bruce Holmes

Invited lecture: “How Solar Cells Work “

by Peter Würfel13:20-13:35 “Identifying the Surfaces of Running

Electrochemical Cells”by Sarp Kaya

“All We Need is Light: Photoprocesses in Chemical Education”

by Michael Walter Tausch13:35-13:50 “Thermo-Oxidative Stability of

Polyethylene for Hot Water Storages”by Klemens Grabmayer

“Fuel Cells and Hydrogen’s Synergy”by Larhrafi Malika

13:50-14:10 “Charge Transport in Organic Photovoltaic Material PTB7”

by Bernd Ebenhoch

“Light Harvesting from First Principles in Time Domain”

by Carlo Andrea Rozzi14:10-14:30 Invited Lecture:

“Phthalocyanine for Molecular Photovoltaics”

by Tomas Torres

Invited Lecture:“Multiscale Simulation of Molecular Photovoltaic Materials and Devices”

by Jenny Nelson

14:30-15:00 Coffee Break

15:00-17:00 Poster SessionHALL 1

17:00-17:30 Plenary Lecture: "6000 Year Story of Solar Energy" by John Perlin17:30-18:00 Poster Prizes and Closing Ceremony

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SITE PLANSAND PRACTICAL INFORMATIONS

SITE PLANS

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VENUE LOCATION

Conference VenueIstanbul Convention and Exhibition Center

Taksim Square

SITE PLANS

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ISTANBUL CONVENTION AND EXHIBITION CENTER

RUMELI UPPER LEVEL

ISTANBUL CONVENTION ANDEXHIBITION CENTER

RUMELI MAINENTERANCE RUMELI HALL

UPPER LEVEL

RUMELI HALLLOWER LEVEL

HALİÇ ROOM

GALATA ROOM

2nd LEVELMarmara Hall

GROUND LEVELAnadolu Auditorium

1st LEVELDolmabahçe ADolmabahçe BDolmabahçe C

LOWER LEVELTopkapı ATopkapı BSultan 1-2-3

RUMELİ HALL MAIN BUILDING

Speakers Preview RoomInternet Corner

WC WC

POSTER AREA

HALL 1 HALL 2

EXH

IBIT

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Main Entrance

Regi

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PRACTICAL INFORMATIONS

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Conference Venueİstanbul Lütfi Kırdar Congress and Exhibition CenterGümüş Cad.No:4 Harbiye 34367 IstanbulPhone : +90 212 373 11 00 (pbx)

Official Language: The official language of the conference is English. No simultaneous translation will be provided.

Conference Venue FacilitiesHallsCongress meeting halls and registration desk located in İstanbul Lütfi Kırdar Congress and Exhibition Center Rumeli Hall Upper Level. The Poster Exhibition will take place in the same level.

Registration Registration Desk (Lütfi Kırdar Congress and Exhibition Center) openning hoursSaturday, the 17th of August 08:00-20:30Sunday, the 18th of August 07:00-19:00Monday, the 19th of August 08:00-19:00

Name BadgeAll participants should wear their name badge visible at all times in order to guarantee access to the scientific programme sessions, lunch area and to the social events.

Conference CertificateYou are welcome to print your personalized certificate of attendance at the Registration Desk.

Conference AssistantsIn addition to the staff at the Conference Information Desk, a number of conference participants available all over the conference area are ready to help participants. They are wearing special T-shirts for easy recognition.

Audiovisual EquipmentAll meeting rooms and auditoria are equipped with standard AV – equipment including PC, projector and screen. Conference assistants/volunteers will assist speakers with uploading of presentations. Please note that support for MAC computers will not be available.

Conference ProceedingsParticipants will receive the book of the Conference Abstracts.

Poster SessionsAll poster sessions will take place in the Poster Exhibition area located in ICEC Rumeli Hall - Upper Level.

Exhibition The exhibition area is located in ICEC Rumeli Hall - Upper Level. Saturday, the 17th of August 08:00-20:30Sunday, the 18th of August 07:00-19:00Monday, the 19th of August 08:00-19:00

Lunch & Coffee BreaksLunches will be served in the İstanbul Lütfi Kırdar Congress and Exhibition Center Rumeli Hall Upper Level.

Internet AccessYou will be able to reach free internet access in congress venue.

Accessibility for WheelchairsElevator is available. Personal assistance is provided too.

ATM/Cash MachinesThere are branches of major banks very close to the congress venue (Cumhuriyet Street). You can have access to the ATM/Cash Machines there.

Accommodation & Tourist Information Desk The accommodation and tour information desk is located in Registration Desk.

Language in the countryThe official language is Turkish. English is widely spoken in major cities and especially in İstanbul.

Currency TL (Turkish Lira) 1 Euro approximately equals to 2,50 Turkish Liras.

PRACTICAL INFORMATIONS

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Sales TaxSales tax (VAT) is included in prices quoted. For non E.U. residents, tax free shopping schemes are available in many shops, which give substantial savings to visitors.

ShoppingFine leather goods, golden and silver jewellery and textiles are considered excellent buys in İstanbul.The pedestrian streets of the city centre, “Taksim Square”, Nişantaşı (just 5 minutes walking distance from the congress venue) and “Grand Bazaar” in the old town Shops are open from 9:00 to 20:00 Monday to Sunday except Grand Bazaar (closed on Sundays). Major shopping malls stay open from 10:00 to 22:00, including weekends. Some of the famous shopping malls are Demirdöken, City’s, Kanyon, İstinye Park and Cevahir.

Time ZoneGMT+2; CET +1; and EST (US -East) +7

Business Hours The workweek in Turkey runs from Monday to Friday. Banks, government offices and majority of corporate offices open at 9 AM and close at 5 PM.

VisasVisas are easily obtained upon arrival at the air port and are required for citizens of most countries.

Electricity220V. European standard round two-pin sockets.

Health Services & RequirementsCities and major touristic towns have a selection of private inter national and public hospitals with good standards. With the exception of vaccination certificates for persons coming from areas where yellow fever is endemic, at the present there are no special health requirements.

SmokingThe Turkish law, in accordance with the Regulations in force in the majority of European Countries and the USA, does not allow smoking in any public

transportation or in any closed public areas.

FoodAs with many Mediterranean nations Turkish food is very healthy, fresh and enjoyable.

WaterIt is recommended that you consume bottled water, which is readily and cheaply available.

CommunicationsTurkey has three GSM operators, all of them offering 3G services and almost 95% coverage over the country. Internet service is available all around the country.

International Dial Code+90

Hotel Check-in/out PolicyNormally check in time at hotels is 14:00. The established check out time is 12:00.

ORAL PRESENTATIONS

SATURDAY17TH OF AUGUST

Saturday, 17th of August

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Opening Statement / 09:05-09:20 / Hall 1

A World Powered Predominantly by Solar and Wind Energy

Walter Kohn

Departments of Physics and Chemistry, UCSB

Total oil plus natural gas production (or consumption), which currently provides about 60 % of global energy use, is expected to peak in 10 - 20 years, followed by a rapid decline. During that same time interval, the developing world will see an approximate doubling of its population as well as an approximate tripling in per capita energy consumption. The near-coincidence of these three galloping trends has created two unprecedented global challenges: The threatened global shortage of acceptable energies and the imminent danger of unacceptable global warming and its consequences.

This lecture describes a possible way of coping with this predicament: A concerted commitment to a changeover from the current era, dominated by oil plus natural gas, to a future era dominated by solar and wind energy, both of which are clean and effectively inexhaustible. However, this optimistic perspective must be tempered with the realization that, unless there are technological breakthroughs, the energy of this future era would be much more costly than at this time. In the Developed World this would require a change of lifestyle: population stabilization and greater energy effectiveness and conservation.

Keywords: A World Powered Predominantly by Solar and Wind Energy

Plenary Lecture / 09:45-10:15 / Hall 1

Silicon Photovoltaics: Changing the World

Martin Green

Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney, Australia 2052

The last few years has seen a dramatic reduction in the cost of silicon solar cells, accelerating opportunities for this technology to make major contributions to future energy supply. With ongoing improvements still to be implemented, silicon cells have the potential to become one of the cheapest and most benign of all available electricity generation options within the coming decade.

The presentation will outline recent market and technological developments, as well as identifying opportunities for both near-term and long-term cost reductions. Some market analysts are projecting silicon module manufacturing costs of US36 cents/Watt by 2017 for leading manufacturers, with opportunities for incremental on-going reductions past this stage.

Ultimately, the inexpensive, high quality silicon wafers resulting from these developments may provide templates onto which can be deposited thin high quality, wider bandgap cells, thereby opening up prospects for even lower costs through substantially increased conversion efficiencies and hence power output. The limiting solar conversion efficiency for a silicon cell is 29%, towards which the manufacturing


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industry should steadily converge. Stacking a single cell on silicon increases the limiting efficiency to 42.5%, two cells to 47.5%, while stacking three cells increases this to beyond 50% efficiency. This is a technology with the potential to change the world.

Keywords: Silicon Photovoltaics: Changing the World

Plenary Lecture / 10:15-10.45 / Hall 1

Personalized Energy (for Everyone) Enabled by the Artificial Leaf

Daniel G Nocera

Harvard University

The ability to duplicate photosynthesis in an inexpensive way sets the stage for the capture and storage of solar energy at the individual level – personalized solar energy. Solar PE drives inextricably towards the heart of the energy challenge by addressing the triumvirate of secure, carbon neutral and plentiful energy for 3 billion low-energy users and by 3 billion people yet to inhabit the planet over the next half century in the non-legacy world. By developing an inexpensive 24/7 solar energy system for the individual, a carbon-neutral energy supply for 1 × 6 billion becomes available.

We have addressed this challenge by creating the artificial leaf, which accomplishes the energy storage process of photosynthesis and does so with:

- Earth-abundant materials- No wires- Direct solar-to fuels process.

Two earth abundant catalysts have been discovered that promote the oxygen evolving reaction (OER) and hydrogen evolving reaction (HER). The ability to operate these catalysts under benign conditions (in water at pH 7 and under 1 atm) has enabled the construction of the artificial leaf, which consists of a silicon wafer, coated with the respective OER and HER catalysts. The artificial leaf, which captures many of the basic elements of the solar fuels process of photosynthesis, is a simple, stand-alone device that provides a means for an inexpensive and distributed direct solar-to-fuels conversion process with low-cost systems engineering and manufacturing requirements. In doing so, this science provides a path for the large scale, distributed, deployment of solar energy.

Keywords: artificial leaf, photosynthesis, solar, poor, energy


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Invited Lecture / 11:00-11:20 / Hall 1 Photovoltaic Materials I

Prospects of Chalcopyrite-Based Thin Film Solar Cells: Towards Competitive Efficiencies

Hans Werner Schock

Helmholtz-Zentrum-Berlin für Materialien und Energie GmbH,Berlin, Germany

Installations of photovoltaic systems cumulated to more than 100 GW worldwide in 2012.Even though thin film solar cells have intrinsic advantages for mass production, more than 90% of the market is covered by crystalline silicon. A dramatic reduction of module prices is accompanied by a significant increase of the conversion efficiency. Notwithstanding their lower cost, thin film solar cells need to reach similar high efficiencies to make them competitive on the present and future energy market. Besides CdTe,multinary compounds like Cu(In,Ga)S,Se2(CIGS) have the potential for future large scale production and application. Small area single junction cells with Cu(In,Ga)Se2 absorber films and a Ga/In ratio of about 0.3 reach efficiencies higher than 20%. Total area module efficiencies approach 16%.Present production lines have an output in the 100 MW to 1 GW range.There is still potential for significant improvements, both of efficiency and production technologies. The multinaryalloy system allows modifications of materials and new devices will overcome efficiency limitations or economic bottlenecks. Wide bandgap compounds are the basis for high efficiency concepts like tandem structures or intermediate gap devices. The amount of rare elements can be reduced e.g. by replacing indium with the combination of a group II and a group IV element to form the kesterite compound Cu2ZnSn(Se,S)4. In this presentation the status of CIGS thin film solar cell production and prospects for the future of thin film photovoltaics are analyzed. The role of these emerging innovative technologies in a future photovoltaic energy scenario is discussed.

Keywords: Prospects ofChalcopyrite-Based Thin Film Solar Cells: Towards Competitive Efficiencies

Oral Presentation - 101 / 11:20-11:35 / Hall 1 Photovoltaic Materials I

Template-Free Electrochemical Deposition of Highly Oriented ZnO Columnar Arrays for Photovoltaic Applications

Vlad Andrei Antohe, Loïk Gence, Sandeep Kumar Srivastava, Luc PirauxInstitute of Condensed Matter and Nanosciences (ICMN/BSMA), Université catholique de Louvain

(UCL)

The fabrication of ZnO nanostructures with controllable features have become subject of intensive research in the last decade, due to their promising potential when used as core elements to improve the performance of various electronic and optoelectronic devices.

In this context, we report an easy one-step template-free electro-deposition method for preparing large arrays of ZnO hexagonal nanocolumns on Au-coated Si substrates. Scanning electron microscopy investigations demonstrated the possibility to obtain a high degree of verticality and orientation of the nanostructures and to control their aspect-ratio in an easy manner. The experiments revealed also the potential of this method to yield high aspect-ratio nanocolumns in a relatively short time synthesis.


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Additional structural studies have shown that the obtained architectures present a well-defined hexagonal symmetry, exhibiting an excellent Wurtzite – type crystallinity.

The facile and low-cost ZnO synthesis method may be an attractive technique to apply on substrates with lower thermal tolerance like flexible and/or transparent media. Moreover, the presented approach may be successfully used in applications requiring well-localized and large aspect-ratio ZnO nanostructures, such as hybrid organic/inorganic solar cells. In the latter situation, a high ordering degree of the nanostructures forming the transparent inorganic electrode, coupled with a very good organic absorber generates an enlarged photo-active area, crucial requirement for enhancing the power conversion efficiency of the photovoltaic elements.

Keywords: ZnO hexagonal nanocolumns; template-free electro-deposition; ZnO nanowires aspect-ratio control; ZnO morphology (SEM) and crystallinity (XRD, TEM) investigations.

Vertically Oriented ZnO Nanocolumnar Arrays

Tilted (left) and top (right) scanning electron microscope (SEM) micrographs, showing ZnO hexagonal nanocolumnar arrays (NCs) obtained by template-free chronoamperometric electro-deposition. The vertically-aligned and nicely distributed ZnO NCs, exhibiting an almost perfect hexagonal symmetry were supported onto Au-coated Si substrates. The insets represent corresponding closed-up magnifications (100 nm scale bars).

Oral Presentation - 103 / 11:35-11:50 / Hall 1 Photovoltaic Materials I

Near-infrared plasmonic activity in metal-doped ZnO derivatives

Arrigo Calzolari 1, Alice Ruini 2, Alessandra Catellani 1

1CNR-NANO Instutute of nanoscience, S3 Center, Modena IT2Dipartimento di Fisica, Univerità di Modena e Reggio Emilia, Modena, IT

Noble metals are conventionally used as plasmonic building blocks in the fields of the telecommunications and energy conversion. Both localized surface plasmons in nanoparticles and surface plasmon polaritons (SPP) at metal/semiconductor interfaces are of interest for optoelectronic applications: the formers can be exploited in photovoltaic systems as amplifier antenna; the latters provide the opportunity of confining and propagating light over long spatial range [1].

However, metals are plagued by large losses in the UV–vis and IR spectral ranges, arising from interband transitions and dissipative scattering events. As an alternative, heavily doped semiconductors can


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exhibit a small negative real permittivity and very small losses at the infrared and longer wavelengths.

Here we present a first principles investigation of the optical and plasmonic properties of metal-doped ZnO systems [2-4], based on DFT, within the Random-Phase-Approximation. We show the formation of SPP resonances at Al:ZnO/ZnO interfaces. These systems present tunable plasmonic activity in the near-IR range and in particular at wavelength relevant for telecommunications (1500 nm) [5]. Then we characterize the plasmon properties of In-doped nanowires that have been envisaged as plasmonic nanoparticles in solar or fuel cells for energy conversion [6].

[1] W.A. Murray et. al, Adv. Mater. 19, 3771 (2007)[2] M. Bazzani, et al., Appl. Phys. Lett. 98, 121907 (2011).[3] A. Catellani, et al, Phys. St. Sol. (2013), in press.[4] A. Calzolari, et al., preprint (2013).[5] G. Naik et al, PNAS 109, 8834 (2012).[6] H.A. Atwater and A. Polman, Nat. Mater. 9, 205 (2010).

Keywords: Plasmonics, energy conversion, DFT, ZnO

Invited Lecture / 11:50-12:10 / Hall 1 Photovoltaic Materials I

Making the Most of the Absorbed Photon: New Insights into Carrier Multiplication in Semiconductor Nanocrystals

Victor KlimovCenter for Advanced Solar Photophysics, Los Alamos National Laboratory, Los Alamos, New Mexico

87545, USA

Quantum-confined semiconductor nanocrystals, or “quantum dots,”are considered promising materials for applications in low-cost solar cells fabricated using solution-based methods. In addition to solution processability, they feature size/shape-tunable optical spectra, as well as a variety of novel physical properties that can enable fundamentallynew schemes for solar energy conversion. Several recent reports have demonstrated the great potential of colloidal nanocrystals for the realization of generation-III photovoltaics (PV) by employing concepts such as hot-electron extraction and carrier multiplication (CM).

CMis a process whereby absorption of a single photon produces multiple electron-hole pairs (excitons). Potentially, it canboost the efficiency of single-junction PV devices to above 40% byincreasing the photocurrent. The first spectroscopic observation of efficient CM in PbSe quantum dots (Schaller & Klimov, Phys. Rev. Lett., 2004) stimulated fervent activity in this area, including spectroscopic and theoretical studies of multiexciton generationand extraction/dissociation, the development of practical devices exploiting CM, as well as theoretical modeling of CM-based solar cells. This presentation provides an overview of recent progress in understanding CM in quantum-confined nanostructures.Specifically, it will discuss the effect of structural parameters such as particle size, shape, and composition on CM yields. Itwill also describe a phenomenological framework for treating CM in terms of two competing energy relaxation pathways, which allows one to rationalize relative variations in CM efficiencies between quantum dots of different compositions, as well as the trends observed during elongation of


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the nanocrystals (that is, the transition from 0D quantum dots to quasi-1D nanorods). Finally, this talk will discuss recent efforts on engineered nanostructures that allow for a manifold enhancement of a multiexciton yield by manipulating the rate of intraband carrier relaxation.

Keywords: Making the Most of the Absorbed Photon: New Insights into Carrier Multiplication in Semiconductor Nanocrystals

Invited Lecture / 11:00-11:20 / Hall 2 Solar Heat Conversion

From Fundamental to Applied Electrochemistry, Electrochemically Nanocoated Selective Surfaces

Figen KadirganDepartment of Chemistry, Istanbul Technical University, Istanbul,Turkey

High efficiency solar collectors need to the selective surfaces to absorb the solar heat. A production method and its process are developed for the mass manufacturing of selective surface coating on copper (1). The coating process is a continuous electroplating process from roll to roll including nano-coated selective layer. Qualification test of solar absorber coating durability is made in collaboration with Institute für Solartechnik SPF –Switzerland. The test procedure applied is basing on the service life assessment methodology developed by the International Energy Agency-SHCP under consideration of latest further developments of the procedure (2,3). The test results confirmed a life time more than 25 years under the thermal load of the absorber surface. There was no any adhesion problem of the absorber coating according to the cross cut test (ISO 2409). Environmental impact of the system is also taken into consideration. In this talk, the results of the research and application will be discussed with market potential of solar thermal systems in EU.

REFERENCES:1. F. Kadırgan, PCT patent, PCT/IB2010/055006, WO/2012/0597892. Carlson B, Möller K, Köhl M, Frei U, Brunold S., Solar Energy Mat. And Solar Cells, 61 (2000) 225-2753. Köhl M, Heck M, Brunold S., Frei U, Carlson B, Möller K, Solar Energy Mat. And Solar Cells, 84 (2004) 275-289

Keywords: solar thermal energy, selective surface, roll to roll


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Oral Presentation - 97 / 11:20-11:35 / Hall 2 Solar Heat Conversion

Experimental validation of fresh water production triangular pyramid solar still with PCM storage

Ravishankar Sathyamurthy 1, Hyacinth J Kennady 1, Nagarajan P.k. 2, Vijayakumar Dharmaraj 3, Sathishkhanna P. 4

1Department of Mechanical Engineering, Hindustan Institute Of Technology And Science, Chennai2Department Of Mechanical Engineering, S.a.engineering College, Chennai

3Department of Mechanical Engineering, Veltech Multitech Dr.rangarajan And Dr.sakunthakla Engineering College, Chennai

4Department of Electrical And Electronics Engineering, Vivekanandha Institute Of Technology And Science, Namakal

The augmentation of fresh water and increase in the solar still efficiency of a triangular pyramid is added with phase change material (PCM) on the basin. Experimental studies were conducted and the effect of productivity of fresh water with and without PCM. Using paraffin as the PCM material performance of the solar still were conducted on a hot, humid climate of Chennai (13°5’ 2” North, 80°16’ 12”East), India. Temperatures of water, PCM, cover were measured using thermocouple. Results show that there is an increase in productivity of fresh water with PCM and during the discharge of heat from the PCM.

Keywords: PCM, Orientation, Geometry, solar still

Oral Presentation - 125 / 11:35-11:50 / Hall 2 Solar Heat Conversion

Study of a composite absorber solar collector for applications in solar drying

Alfa Oumar Dissa 1, Gerhard Stryi Hipp 2, Jean Koulidiati 1

1University of Ouagadougou, Burkina Faso2Fraunhofer Institute for Solar Energy Systems, Germany

In this study, a prototype of air solar collector with a composite absorber is designed and experimented and its operating mode is modelled and simulated. Its absorber results from the coupling of a “corrugated iron sheet” absorber and a “porous” absorber made of a mesh of aluminium. The operation of this collector was studied in unsteady state by taking into account heat capacity effects in its different parts. Temperatures in the collector were then simulated by solving the transient energy balance equations relating its various parts. Solutions of discretized equations gave different temperatures versus time of the day and distance from collector inlet. The results showed that at solar midday of a typical day of May the mean temperatures of the absorber and the glass cover were about 107°C and 79.6°C for an ambient temperature ranging between 30 and 35°C. At this time, the airstream temperature at collector outlet was close to 75°C and the useful energy recovered by the collector was about 400W per m² of captation surface. Thus, the rises in temperature of airstream along the day ranged from a few degrees in the beginning and the end of day to about 37°C at solar midday. Experimental and simulated temperature curves were very close and the adopted simulation model allowed predicting suitably the


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various temperatures in the collector. This solar collector was then appropriate to heat air for drying of agricultural products.

Keywords: solar, collector, composite absorber, air, unsteady state

Invited Lecture / 11:50-12:10 / Hall 2 Solar Heat Conversion

Design, Fabrication and Analysis of Photovoltaic/Thermal (PV/T) Hybrid Collector

Halil İbrahim Dağ 1, Günnur Koçar 2, Ömer Faruk Yüksel 3

1Solimpeks Solar Energy Corp., Fevzi Çakmak Mh., 10753 sk., No.3 Karatay-Konya, Turkey2Solar Energy Institute, Ege University, 35100 Bornova-Izmir, Turkey

3Department of Physics, Faculty of Science, Selçuk University 42075 Konya, Turkey

Photovoltaic/thermal (PV/T) technology refers to the integration of a Photovoltaic (PV) module and a conventional solar thermal collector in a single equipment. Two main objectives in PV/T applications are both to minimize the efficiency reduction of PV modules with increasing temperature and also to benefit from the collector in point of thermal energy. In this study, the design and the fabrication of a water-type photovoltaic/thermal (PV/T) collector is performed, in which the heat produced by the solar radiation will be efficiently transposed to the thermal collector and water. The thermal part is integrated with the single crystal silicon PV cells by using the lamination technique and PV/T collector is fabricated as a single piece. The electrical and thermal efficiency parameters of PV/T collector are measured and analyzed.

Keywords: PV/T hybrid collector, photovoltaic, efficiency.

Invited Lecture / 13:30-13:50 / Hall 1 Photovoltaic Materials II

Hybrid Tandems of Solar Cells Tunable by Ionic Charging

Anvar A Zakhidov, Alex Cook, Jonathan YuenThe Alan MacDiarmid NanoTech Institute, University of Texas at Dallas, Richardson, Texas, USA

We describe how performance of hybrid OPV tandems can be significantly improved in reconfigurable p-i-n structures in which doping is achieved by double layer charging in ionic liquids. We have designed true hybrid devices combining solid and liquid parts in one monolithic porous structure: OPV combined with supercapacitor (SC) (based on different ionic liquids) via a common transparent CNT electrode. Such a hybrid OPV tandem device, can be viewed also as electrochemically gated CNT/OPV with several new advantages for tuning.

In one mode of demonstrated operation the proper bias applied to capacitor sub-cell of tandem, dopes CNTs by double layer charging (DLC) turning it from anode to cathode. This leads to formation of photo-diode and drastic improvement of OPV cell performance: order of magnitude increased Isc, enhanced


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FF and Voc, leading to efficiency of > 3.4 %. In another mode, (at zero bias) the photogeneration in inverted OPV sub-cell leads to photoinduced doping of CNT anode, resulting in self-charging of SC capacitor cell by opposite DLC due to ions redistribution within pores of CNT.

The physical processes in ionically tuned OPV tandems are discussed in terms of work function modulation in CNT, better ohmic contact of CNT electrode with organic layers and formation of p-i and n-i junctions inside OPV layers, all of which contribute to better separation of photogenerated carriers and their improved collection. Bleaching effects are found upon photoexcitation in both in CNT (in IR region) and in PHT, independently confirming the DLC ionic doping.

Keywords: hybrid solar cell tandem, carbon nanotube, ionic liquid, supercapacitor, photocharging

Oral Presentation - 419 / 13:50-14:05 / Hall 1 Photovoltaic Materials II

Efficiency Limits of Bulk Heterojunction Solar Cells

Markus ScharberLinz Institute for Organic Solar Cells, Johannes Kepler University Linz, Austria

Thin film photovoltaic cells based on solution processable organic semiconductors have attracted remarkable interest as a possible alternative to conventional, inorganic photovoltaic technologies. Among others the following the following key advantages of organic photovoltaic (OPV) devices have been identified: low weight and flexibility, semitransparency, easy integration into other products, significantly lower manufacturing costs compared to conventional inorganic technologies, short energy payback times and low environmental impact during manufacturing and operations. One of the key requirements for large scale commercialization of organic solar cells is achieving higher power conversion efficiency. Different approaches to estimate the ultimate power conversion efficiency of bulk heterojunction solar cells and their current limitations will be discussed. Concepts for higher efficiencies including third generation will be summarized.

Keywords: Efficiency Limits of Bulk Heterojunction Solar Cells

Oral Presentation - 113 / 14:05-14:20 / Hall 1 Photovoltaic Materials II

Solar cell on ZnO nanorod window and extremely thin CIS absorber prepared by chemical spray

Erki Kärber 1, Aimi Abass 2, Samira Khelifi 2, Marc Burgelman 2, Atanas Katerski 1, Malle Krunks 1

1Department of Materials Science, Tallinn University of Technology, Tallinn, Estonia2Department of Electronics and Information Systems (ELIS), Gent University, Gent, Belgium

We report on the advance on characterization of extremely thin absorber (eta) solar cell prepared by the low cost Chemical Spray Pyrolysis (CSP) method. The nanostructured ZnO/In2S3/CuInS2 superstrate configuration solar cell deposited by the CSP show conversion efficiency up to 4.2%. The aim was to find the crucial non-idealities and recombination mechanism in dark and at illumination, and relate to the imperfections of the cell materials. We measured current-voltage in dark and under varied


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illumination intensities 0.5-100 mW/cm2 and admittance, both in the temperature range of 100-360 K; and quantum efficiency at room temperature. We extensively studied the electrical characteristics of the cell based on the nano-columnar ZnO window layer. Interestingly, the nanostructured cell performs better than a ´flat´ reference cell by spray only at illumination intensities higher than 2 mW/cm2. The nanostructured cell show better light scattering and absorption ability (Fig. 1) accompanied by a less effective charge carrier separation, compared to the reference cell. Admittance spectroscopy shows that the structured cell has a higher concentration of defects and an additional band of defects. This further explains the limited performance enhancement the structured cell has over the flat cell. The common analysis techniques established for thin film solar cells can not easily be transferred to the sprayed eta cell, due to the cell failing to meet certain prerequisitions. Nevertheless, we succeeded in pinpointing many of the bottlenecks which help us further develop the nanostructured eta cell by the cheap and rapid spray method.

Keywords: Chemical Spray Pyrolysis, Inorganic nanostructured solar cell, Superstrate cell, Extremely thin absorber (ETA)

Fig. 1.

External quantum efficiency (EQE) of the structured and the flat ZnO/In2S3/CuInS2 solar cell grown by the Chemical Spray Pyrolysis method. An improvement of the EQE is assigned to an improved photon absorption in the structured cell.


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Invited Lecture / 14:20-14:40 / Hall 1 Photovoltaic Materials II

Thin Film Polycrystalline Compound Photovoltaic Technologies: Status and Future Prospects

Bulent BasolEncoreSolar, Inc., San Jose, California, USA

Thin film solar cells based on CdTe and Cu(In,Ga)(Se,S)2 -(CIGS) have been in development since 1970’s. Efficiency values of these compound semiconductor devices have recently reached the impressive 19-21% range in the laboratory. With the rapid growth of the photovoltaic market, thin film technologies attracted considerable amount of investment in the 2002-2008 period. As a result, various technologies based on a wide variety of vacuum and non-vacuum based thin film growth techniques, such as vapor deposition, electrodeposition and ink deposition, have been developed and put into multi megawatt pilot operations. Despite the rather impressive technical results, however, many of these technologies could not be transferred into large scale production due to the precipitous drops observed in the price of poly-Si source material and, consequently, the crystalline Si based PV modules in the years following 2008. At the present time the thin film CdTe and CIGS technologies have a market share of around 10% and they have so far produced champion module efficiencies in the 15-16% range. In this presentation we will briefly review the development and status of the various CdTe and CIGS photovoltaic technologies and provide insight as to how these technologies can play a role in the expanding photovoltaic markets of the future.

Keywords: thin film solar cell, CdTe, CIGS

Invited Lecture / 13:30-13:50 / Hall 2 Synthesis of Materials I

Two-dimension-conjugated polymers for high efficiency polymer solar cells

Yongfang LiInstitute of Chemistry, Chinese Academy of Sciences

Bulk-heterojunction polymer solar cells (PSCs) have attracted great attention in recent years, because of their advantages of low cost fabrication, light weight and flexibility. PSCs are usually composed of a blend layer of conjugated polymer donor and soluble fullerene derivative (such as PCBM) acceptor sandwiched between an ITO positive electrode and a low work-function metal negative electrode. For achieving higher power conversion efficiency of the PSCs, great efforts have been devoted to the design and synthesis of new donor and acceptor photovoltaic materials with broad absorption in visible region, suitable electronic energy levels and high charge carrier mobility[1]. In this presentation, I will talk about our recent progress on the two-dimension-conjugated (2D-conjugated) polymer photovoltaic donor materials[2-4], including the 2D-conjugated copolymers and solution-processable 2D-conjugated organic molecules based on bithienyl-substituted benzodithiophene (BDT) unit. Power conversion efficiency of the OSCs based on our new donor materials reached 7~8%.


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References:[1] Y. F. Li, Acc. Chem. Res. 2012, 45, 723–733.[2] L. J. Huo, S. Q. Zhang, X. Guo, F. Xu, Y. F. Li, J. H. Hou, Angew. Chem. Int. Ed., 2011, 50, 9697-9702.[3] Y. Huang, X. Guo, F. Liu, L. J. Huo, Y. N. Chen, T. P. Russell, C. C. Han, Y. F. Li, J. H. Hou, Adv. Mater. 2012, 24, 3383–3389.[4] S. L. Shen, P. Jiang, C. He, J. Zhang, P. Shen, Y. P. Yi, Z. J. Zhang, Z. B. Li, Y. F. Li, Chem. Mater. 2013, DOI: 10.1021/cm400782q.

Keywords: 2D-conjugated polymers, polymer solar cells, 2D-conjugated organic molecules, bithienyl benzodithiophene

Oral Presentation - 055 / 13:50-14:05 / Hall 2 Synthesis of Materials I

D-A(D) polymers with differently conjugated donor side groups at the acceptor units for polymer solar cells

Xiaobin Peng, Hongmei Qin, Lisheng Li, Junbiao Peng, Yong CaoSouth China University of Technology

Though thienyl groups were attached to benzodithiophenes (BDT) moieties of donor-acceptor (D-A) backbones to form D(D)-A polymers to improve the photovoltaic performance very recently, it is still unknown how the 2-D conjugated structures influence the photovoltaic properties. Furthermore, the photovoltaic properties of D-A(D) polymers, in which donor side groups are attached to the acceptor units of D-A polymers, have not been investigated.

In this study, four new D-A(D) polymers — PBDT-PTQ, PBDT-PTTQ, PBDT-TQ and PBDT-TTQ, bearing the same backbone of alternative BDT and quinoxaline units but with phenylene thienyl, phenylene di-thienyl, thienyl and di-thienyl groups (other donors), respectively, attached at 2 and 3 positions at the acceptor quinoxaline units, were designed and synthesized to investigate the impacts of the conjugated side chains at the acceptor units on the photovoltaic properties of polymers. The power conversion efficiencies (PCEs) of the polymer solar cells based on PBDT-TQ:[6,6]-phenyl-C-70-butyric acid methyl ester (PC70BM) and PBDT-PTQ:PC70BM reach to 4.39% and 3.58%, respectively, which are 43% and 17% higher, respectively, than that of a reported alkylphenyl substituted polymer with the same main chain. However, the PCEs based on PBDT-TTQ and PBDT-PTTQ, in which an additional thiophene was added at each side chain of PBDT-TQ and PBDT-PTQ, respectively, declined. The mechanism how the conjugated side chains affect the performance of the PSCs is also discussed.

Acknowledgements.

This work was financially supported by the grants from the National Natural Science Foundation of China (51073060, 50990065, and 51010003), International Science & Technology Cooperation Program of China (2010DFA52150,2013DFG52740).

Keywords: D-A polymer, 2-D, OPV


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Oral Presentation - 191 / 14:05-14:20 / Hall 2 Synthesis of Materials I

Synthesis and characterization of medium bandgap polymers with benzo[1,2-b:4,5-b’]dithiophene donor units for solar cell

applications

Desta Antenehe Gedefaw 1, Margherita Bolognesi 2, Marta Tessarolo 2, Mirko Seri2, Wenilu Zhuang 1, Patrik Henriksson 1, Ergang Wang 1, Michele Muccini 2,

Mats R. Andersson 1

1Department of Chemical and Biological Engineering / Polymer Technology, Chalmers University of Technology,Gothenburg, Sweden

2Consiglio Nazionale Delle Ricerche, Bologna, Italy

Research on polymer solar cells has increased in recent times due to the possibility of fabricating cheap solar cell devices to exploit the huge amount of sun energy. In bulk heterojunction (BHJ) device structure a blend of conjugated polymer and derivatives of C60 are used [1].

The synthesis of conjugated polymers that fulfill desired properties is very essential for achieving improved power conversion efficiency (PCE) of the solar cell devices. Ideal HOMO and LUMO energy levels, strong absorption in the visible and near infrared region, ideal morphology of polymer-acceptor blend and high hole mobility are some of the needed properties. The PCE of polymer solar cells reached 7-8% in the past few years [2] due to the synthesis of many new polymers and device optimization work.

Of the different types of polymer building units, benzo[1,2-b:4,5-b’]dithiophene (BDT) has attracted attention due to its inherent advantages [3]. BDT has rigid structure which promotes inter-chain interaction of polymer chains and enhances mobility of charge carriers.

In this work, we synthesized a series of polymers by Stille coupling reaction between the BDT monomers and different acceptors. The optical and electrochemical properties of the polymers were measured. Solar cells were fabricated from the polymers together with PCBM[60] or PCBM[70] and up to 5.5% PCE was obtained.

References1. Chem. Rev. 2007, 107, 1324.2. Chem. Mater. 2012, 24, 4766. 3. J. Am. Chem. Soc. 2013, 135, 4656.

Keywords: Conjugated polymer, Benzodithiophene, Efficiency


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Invited Lecture / 14:20-14:40 / Hall 2 Synthesis of Materials I

Synthesis as a key tool in the development of materials for organic electronics

Ullrich ScherfBergische Universitaet Wuppertal, Macromolecular Chemistry Group, Wuppertal, Germany

The lecture presents a couple of synthesis driven approaches towards systematic control on morphology and (opto)electronic properties of conjugated (co)polymers. The examples include conjugated polyelectrolytes (CPEs) for thin charge extraction interlayers of organic solar cells [1], donor (co)polymer design for organic solar cells [2,3], and all-conjugated rod-rod block copolymers and their self-assembly properties [4-6].

References [1] J. H. Seo, A. Gutacker, Y. Sun, H. Wu, F. Huang, Y. Cao, U. Scherf, A. J. Heeger, G. C. Bazan, J. Am. Chem. Soc. 2011, 133, 8416.[2] S. Kowalski, S. Allard, U. Scherf, ACS Macro Lett. 2012, 1, 465.[3] R. Tautz, E. da Como, T. Limmer, J. Feldmann, H.-J. Egelhaaf, E. von Hauff, V. Lemaur, D. Beljonne, S. Jilmaz, I. Dumsch, S. Allard, U. Scherf, Nature Comm. 2012, 3, DOI: 10.1038/ncomms1967.[4] Tu, G., Li, H.; Forster, M., Heiderhoff, R., Balk, L. J., Sigel, R., Scherf, U.; Small 2007, 3, 1001.[5] U. Scherf, A. Gutacker, N. Koenen, Acc. Chem. Res. 2008, 41, 1086.[6] R. C. Mulherin, S. Jung, S. Huettner, K. Johnson, P. Kohn, M. Sommer, S. Allard, U. Scherf, N. C. Greenham, Nano Lett. 2011, 11, 4846.

Keywords: Conjugated Polymers, Organic Photovoltaics, Conjugated Polyelectrolytes, All-conjugated Block Copolymers

Invited Lecture / 15:00-15:20 / Hall 1 Photovoltaic Materials III

Low-Resistance Back Contact Buffers for Thin-Film CdS/CdTe Solar Cells

Ching W Tang, Hao Lin, Wei Xie, Hsiang N WuDepartment of Chemical Engineering, University of Rochester, Rochester, NY

Among the hurdles to producing high-efficiency and long-life n-CdS/p-CdTe thin-film solar cells, the formation of ohmic and stable back contacts to p-CdTe is most challenging due to the generally high resistivity and deep valence band associated with the vapor-deposited p-CdTe films. A solution to this problem has been successively developed by using a high work-function, vapor-deposited MoOx layer as an effective ohmic contact buffer, an approach adapted from organic photovoltaic devices. This method has been found to be useful for the fabrication of ultra-thin CdS/CdTe solar cells and resulted in improvements in efficiency and stability.

Keywords: CdS/CdTe solar cells, MoOx, transition metal oxides, back contacts[2] S. Kowalski, S. Allard, U. Scherf, ACS Macro Lett. 2012, 1, 465.[3] R. Tautz, E. da Como, T. Limmer, J. Feldmann, H.-J. Egelhaaf, E. von Hauff, V. Lemaur, D. Beljonne, S.


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Jilmaz, I. Dumsch, S. Allard, U. Scherf, Nature Comm. 2012, 3, DOI: 10.1038/ncomms1967.[4] Tu, G., Li, H.; Forster, M., Heiderhoff, R., Balk, L. J., Sigel, R., Scherf, U.; Small 2007, 3, 1001.[5] U. Scherf, A. Gutacker, N. Koenen, Acc. Chem. Res. 2008, 41, 1086.[6] R. C. Mulherin, S. Jung, S. Huettner, K. Johnson, P. Kohn, M. Sommer, S. Allard, U. Scherf, N. C. Greenham, Nano Lett. 2011, 11, 4846.

Keywords: Conjugated Polymers, Organic Photovoltaics, Conjugated Polyelectrolytes, All-conjugated Block Copolymers

Oral Presentation - 111 / 15:20-15:35 / Hall 1 Photovoltaic Materials III

Quantum dots for photovoltaic solar cell

Sihem JaziriLPMC, University of Carthage, Tunisia

The technology includes solar cells with absorber layers that rely on quantum physics (e.g., confined excitons—bound electron-hole pairs), including organic or polymer-based cells, dye-sensitized cells, or cells using quantum dots/wires, quantum wells, or superlattice technologies. We study the photocurrent in a single InAs/GaAs self-assembled quantum dot embedded in the intrinsic region of an n-i-Schottky photodiode based on a two-dimensional electron gas. The electron tunneling rate is described accurately by a theoretical model and measured as a function of the vertical electric field in experiments, yielding information about the electron confinement energy. We demonstrate that the device can operate as photovoltaic cell and conclude by proposing an optical device that is now feasible.

Keywords: Quantum dots exciton photocurrent


Enhancement of organic photovoltaic devices performance and stability by addition of nanoparticles

Emmanuel Kymakis 1, George Kakavelakis 1, Emmanuel Koudoumas 1, Emmanuel Stratakis2

1Center of Materials Technology & Photonics and Electrical Engineering Department, Technological Educational Institute (TEI) of Crete

2Institute of Electronic Structure and Laser (IESL) Foundation for Research and Technology-Hellas (FORTH)

This presentation will review the recent progress of our group on nanoparticles-based plasmonic organic photovoltaic devices1. Enhancement of both the efficiency and stability of bulk heterojunction polymer-fullenene (P3HT:PCBM, P3HT:ICBA, PCDTBT:PC70BM) devices is demonstrated by the addition of Au or Al NPs in either the active layer or in the interface between the buffer and the active layers. A performance enhancement of 20% to 32% was observed in all polymer-fullerene systems. The highest enhancement of 32% was observed with Al NPs in P3HT:PCBM, while the highest efficiency of 6.1% was observed in the PCDTBT:PC70BM. Moreover, the devices with Au and Al in the active layer die after


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~65 hrs and ~150 hrs under continuous illumination respectively, compared with the pristine devices which die after ~30 hrs. Likewise, the use of graphene oxide (GO) or GO-Au NPs film as buffer layers, instead of the traditional PEDOT:PSS can significantly improve the devices lifetime and efficiency2. The plasmonic GO-based devices exhibited a performance enhancement by 28% compared to the PCDTBT:PC70BM devices using the traditional PEDOT:PSS layer, leading to a maximum efficiency of 6.64%. This enhancement can be attributed to the multiple LSPR absorption bands arising from the three different NPs employed.[1] E. Stratakis, E. Kymakis, Materials Today DOI: 10.1016/j.mattod.2013.04.006 (2013)[2] E. Stratakis, M. Stylianakis, E. Koudoumas, E. Kymakis, Nanoscale, 5 (10), 4144-4150 (2013)

Keywords: plasmonic,graphene,photovoltaic


Preparation and Characterization of Nanocomposite Nitrogen-doped TiO2/CdS for Dye-sensitized Solar Cells

Cahyorini Kusumawardani, Sri Handayani, Kh SugiyartoYogyakarta State University

The nanocomposite N-TiO2/CdS nanocomposite have been synthesize through direct formation of nanosize CdS on the nitrogen-doped TiO2 film. Its surface modified of N-TiO2 film was then applied in dye-sensitized solar cells with and without the use of dye sensitizer. The component of the nanocomposite was studied by X-Ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS), while the structure of the film was characterized with gas sorption analyzer and scanning electron microscopy (SEM). The charge separation and diffusion processes inside modified and unmodified N-TiO2 film were analyzed using diffuse photovoltage sepectroscopy. The result showed that the CdS particles were 4-7 nm and discrete on the surface of N-TiO2 film. The diffusion signals revealed that the traps on N-TiO2 surface were extremely reduced in the presence of CdS. The use of dye sensitizer was resulting a higher overall solar cell efficiency (8.7%) compared to only CdS sensitized N-TiO2 (6.9%). It was also observed significant enhanced photoresponse in the solar cells based on this nanocomposite compared to the solar cells based on unmodified N-TiO2 or CdS/TiO2. The enhancement is related to the synergistic effect of CdS sensitization and N-doping that facilitate hole transfer/transport from CdS to N-TiO2 through oxygen vacancy states mediated by N-doping. The result also demonstrated that designing and manipulating the band energy in composite nanomaterial is a fundamental factor to improve the charge separation and transport in solar cells system.

Keywords: nanocomposite, dye-sensitized solar cells, N-doped TiO2


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Effect of Deposition Temperature of CdS Films on the Performance of Inverted Type Solar Cells

Hasan Yüksel Güney1, Sureyya Aydın Yuksel2, Gülbeden Çakmak1, Serap Güneş2

1Department of Physics, Kocaeli University, 41380 Kocaeli, Turkey.2Department of Physics, Yildiz Technical University, 34210, Esenler/Istanbul, Turkey.

We investigated the optical and morphological properties of CdS thin films which were considered as electron collection layers for inverted type solar cells. Devices were fabricated in the form of ITO/CdS/P3HT:PCBM/Ag. Thin films of CdS were deposited using spray pyrolysis technique at substrate temperature ranging from 200oC±5 to 450oC±5. The deposition temperature of CdS thin films was optimized for the PV devices. The best PV parameters were achieved at substrate temperature of 400oC. We found that the Jsc changes significantly depending on the substrate temperature. We achieved an open circuit voltage (Voc) of 550 mV and a short circuit current density (Jsc) of 3.10 mA/cm2, leading to a power conversion efficiency (PCE) of 0.48 %.

Study was supported by the Research Found of the Kocaeli University (Project number: 2011-61).

Keywords: CdS, inverted, spray pyrolysis


A novel efficient solid state dye solar cells based on single wall carbon nanotube doped titania

Giampiero Ruani 1, Tanja Ivanovska 1, Chiara Dionigi 1, Michele Muccini 1, Marija Radoicic 2, Zoran V. Saponjic 2, Franco Corticelli 3, Vittorio Morandi 3,

Luca Ortolani 3, Hristina Spasevska 4

1Consiglio Nazionale delle Ricerche, Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN), Bologna, Italy2University of Belgrade, Vinča Institute of Nuclear Sciences, Belgrade, Serbia

3Consiglio Nazionale delle Ricerche, Istituto per la Microelettronica e i Microsistemi (CNR-IMM), Bologna, Italy4Faculty of Electrical Engineering and Information Technologies, Ss. Cyril and Methodius University, Skopje,

Macedonia

One of the limiting factors in the efficiency of solid state dye solar cells is the relatively low mobility of electrons in the TiO2 mesoporous photoanode with respect to the hole mobility in the organic semiconducting material [1]. To enhance charge separation and improve charge transport, water suspensions of single wall carbon nanotubes (SWCNTs), at different concentrations, were used in the preparation of the titania paste for the photoanode deposition. Already at very low SWCNTs concentration (>0.04 wt%), the conductivity of the mesoporous layer increased by several orders of magnitude with respect to the “undoped” one.

In liquid dye cells, the short circuit current (Isc) increases with the electron mobility associated with the increment in SWCNTs concentration but this is not directly reflected in an equivalent improvement in efficiency because the uncoated SWCNTs at the titania/electrolyte act as charge recombination centers (both Voc anf FF decrease), and, as already observed by other autors [2], the highest enhancement in efficiency is about 10% with respect to SWCNTs free cells; the increment can be enhanced in a further


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step decorating the mesoporous structure by using a colloidal titania nanoparticles solution.

In the case of solid state dye cells, with spiro-OMeTAD as hole conductor, charge recombination at the interface is reduced and the larger electron transport along the nanotubes is dominating leading to a higher increase in efficiency than in the liquid dye cells.

[1] H.J.Snaith, and M.Grätzel, Adv. Mater. 19, 3643, 2007. [2] J.Chen et al., J. Phys. Chem.C 116, 14848, 2012.

Keywords: conversion efficiency, photoanode, Raman spectroscopy, charge recombination, charge collection

(a) SEM image of TiO2/SWCNTs composite; (b) I-V characteristics of TiO2/SWCNTs composite film measured under 1 sun AM 1.5 illumination; (c) Raman images of TiO2/SWCNTs composite films built integrating Raman spectra (d) from 1550 cm-1 to 1650 cm-1

.


Kesterite-based solar cells by electrodeposition-selenization – Effects of precursor morphology and composition on device

properties

Diego Colombara 1, Alexandre Crossay 1, Erika V Robert 1, Laura Vauche 2, Salvador Jaime 2, Pierre Philippe Grand 2, Phillip J Dale 1

1Laboratory for Energy Materials, University of Luxembourg, Luxembourg2NEXCIS, Rousset, France

The need to find alternatives to In, Ga, Cd and Te-based absorber materials in thin-film solar cells is urgent if we want to address availability and toxicity issues in a realistic timeframe. Besides containing only non-toxic and Earth-abundant elements, Cu2ZnSnS4 (CZTS) aka Kesterite is a direct band-gap semiconductor with promising light-absorbing properties as a substitute of Cu(In,Ga)(S,Se)2.

We investigate Kesterite formation by a two stage process [1]: electrodeposition of Cu/Sn/Zn precursors and selenization.

Metal-electroplating is a well-established industrial technology. Therefore, formation of photovoltaic Kesterite thin-films via electrodeposition/chalcogenization is an industrially-relevant process, and devices obtained this way have achieved efficiencies up to 7.3%. However, the synthesis of single-phase high-quality layers via this two-stage route can pose scientific challenges [2]. CZTSe is a quaternary


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system, this implies that the reaction pathway can easily lead to off-stoichiometry with detrimental secondary phase segregation [3].

In this work the effect of the microstructure of the upper Zn-layer on the properties of the resulting CZTSe films and devices was investigated.

Devices obtained from dendritic precursors have poor electrical properties, with efficiencies up to 3.3%. Devices obtained from compact Zn layers have reduced shunt conductance and efficiencies of ca.6%.

[1] Basol, B. M. IEEE Transactions on electron devices 1990, 37, 418[2] Colombara et al. Journal of Solid State Chemistry 2012, 186, 36[3] Scragg et al. ChemPhysChem 2012, 13, 3035

Acknowledgements

LEM team members are gratefully acknowledged for help and discussion. Funding was provided by the EU through the FP7 Programme 2007-2013, grant agreement nº 284486.

Keywords: CZTSe Kesterite, thin film solar cell, electroplating, selenization, precursor morphology, two-stage process

Fig. 1

SEM top views of the different Cu/Sn/Zn precursors employed for the synthesis of CZTSe films (a-b). Optical microscope images of the corresponding selenised films (c-d).


Inorganic Nanostructures for Organic Solar Cells

Tsukasa Yoshida 1, Lina Sun 1, Yuta Ogawa 1, Masao Yoshizaki 1, He Sun 1, Matthew White 2, Niyazi Serdar Sariciftci 2, Kazuhiro Manseki 3

1Research Center for Organic Electronics (ROEL), Yamagata University, Yonezawa, Japan2Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University of Linz, Linz, Austria

3Center of Innovative Photovoltaic Systems (CIPS), Gifu University, Gifu, Japan

While many people are concerned about the stability of organic materials used in organic solar cells, it is ironical to realize that degradation of inorganic materials such as Ca:Al and ITO electrodes is the typical cause of instability of such devices. Also, the device performance often strongly depend on the property of inorganic electrodes for collection of charge carriers. That gives us a motivation to develop methods to synthesize inorganic nanostructures for organic solar cells and hybrid solar cells in novel structures. Chemical solution reactions for size and structure controlled nanoparticles and electrochemical precipitation for nanostructured thin films were developed for electron and hole conducting materials such as ZnO, TiO2 and CuSCN. One of the most beautiful example is the


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electrochemical nanostructuring of CuSCN in nanorod and porous crystal structures. While the former is expected to serve as hole collecting 3D electrode in BHJ solar cells, the latter having a high surface area and well crystallized structure is useful for cathodic dye-sensitization to be combined with dye-sensitized photoanode for tandem solar cells.

Keywords: Electrodeposition, Nanostructure, Hybrid, Solar Cell

Figure


Solar electricity generated and stored with organic materials

Olle InganäsBiomolecular and organic electronics, IFM, Linköpings Universitet, Linköping, Sweden

The conversion of light to electricity with organic photovoltaic devices has taken great strides over the last decade, and power conversion efficiency of 12 % in tandem organic solar cells is reported. The low mobility in these disordered materials limits the design possibilities of devices, as electrodes cannot be located at a far distance from the photocurrent generating elements. The energy dissipation in electrodes is therefore a considerable loss mechanism. We describe some recent contributions towards light management in thin film solar cells based on blends of conjugated polymers and fullerene, where semitransparent electrodes are used as anode and cathode. These semitransparent cells can be improved in efficiency by returning the transmitted light for absorption once more, or


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many times more. With these light trapping approaches, improved photocurrents are obtained. With semi-transparent light scattering traps, also balancing of photocurrent between tandem solar cells is possible.

The electricity generated need storage over time, to make it available at night. We have developed new biopolymer based composite materials incorporating the conjugated polymer polypyrrole and lignin derivatives. The lignin derivative is incorporate as an anion and dopant in the polypyrrole, which act as the electronic wire accessing quinone groups generated from the lignin chemical structure. Much improved charge density is obtained. Inclusion of more redox species is possible, to increase the charge density, and to modify the redox potential where charge is stored. This is demonstrated with alternative smaller quinones, as well as with polyoxymetalates. Supercapacitors built from these electrodes show promise towards storage of intermittent electricity sources.

Keywords: polymer solar cells; supercapacitors; light management

Oral Presentation - 11 / 15:00-15:20 / Hall 2 Surveys and Examples

A Study on Integrated Solar Combined Cycle Power Plant for Turkey

Ahmet Emin Şentürk 1, Coşkun Fırat 2

1Makine Mühendisliği, Gebze Yüksek Teknoloji Enstitüsü, Kocaeli, Turkey2Energy Institute, Istanbul Technical University, Istanbul, Turkey

Integrated solar combined cycle systems (ISCCS) are a promising alternative to both economics and energy for the conversion of solar energy. The performance of the system is tightly linked to the intensity of solar energy input and the transfer method of solar energy to combined cycle. Given the sunshine duration and solar energy intensity, an ISCCS application will be realistic and useful in the meaning of energy production in the suitable regions in Turkey.

In this study, first the situation of Turkey was examined in terms of solar radiation and then the cities which have high potential for solar energy were determined. By applying the necessary criteria to the determined provinces, the town Karapinar of Konya was identified as the most appropriate area for the installation of a CSP plant.

And then, the conditions of the practiced incentive constituents to be utilized under the Renewable Energy Law and the New Incentive System are determined.

The current and future status of Konya province and Karapinar town are discussed in terms of energy investments by the strengths and weaknesses, opportunities and threats (SWOT) analysis which is to be done before the economic analysis of ISCCS.

In the economic analysis of the ISCCS, a payback period is calculated for a sample system. Then, the lifetime net profit of the plant and share of the CSP system over ISCCS are calculated.

Keywords: Integrated solar combined cycle systems, solar radiation, SWOT analysis, economic analysis, Turkey


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Survey of Renewable Energy Businesses in Malawi

Esther Phiri 1, Bob Lloyd 2

1University of Malawi-The Malawi Polytechnic, Blantyre, Malawi.2University of Otago, Dunedin, New Zealand.

Renewable energy (RE) provides energy that is sustainable while at the same time contributing to climate change mitigation and adaptation efforts. RE also provides for energy security through energy diversification and assists in the creation of new industries; and jobs through businesses and organisations. This study was carried out in Malawi, a small densely populated country in Southern Africa in which RE contributes approximately 1 % of the total energy supply of the country. The aims of the study were to investigate the role of the renewable energy companies in the RE industry in Malawi and the status of RE from the point of view of renewable energy companies. It was achieved by undertaking a qualitative evaluation of renewable energy uses, impacts, and barriers to renewable energy supply uptake. The method of data collection was one-on-one interview using a structured questionnaire. The study revealed that solar PV leads the market in Renewable Energy Technologies (RETs) and that great potential exists for RETs in the country. However, the country does not manufacture any RET products hence they are still very expensive. This cost is exacerbated by high transport costs to the rural areas where most of the installations are carried out. Other problems include influx of substandard amorphous solar panels which are cheaper and also overloading of solar PV systems by users. The study recommends among other things: research in the possibility of venturing into manufacture, user training and close monitoring of Solar PV systems’ usage.

Keywords: Renewable Energy Businesses, Solar PV, Malawi


African Network for Solar Energy (ANSOLE): Bridging Africans in Capacity Building and Use of Sustainable Energy Sources and

Technologies

Daniel Ayuk Mbi EgbeLinz Institute for Organic Solar Cells, Physical Chemistry, Johannes Kepler University Linz,

Altenbergerstr. 69, 4040 Linz, Austria

ANSOLE (www.ansole.org) was officially launched in February 2011 in Linz Austria three months after it was initiated in November 2010 in Sousse, Tunisia, by African scientists. It is a platform of exchange among various stakeholders, who are all devoted to promote in a concerted way the use of sustainable energy to address the present acute energy problem in Africa while preserving and protecting the environment. It is a fast growing entity presently represented in more than 30 African countries and has become the African mouthpiece in renewable energy related issues.


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The three main goals of ANSOLE are:

- To foster training and education in renewable energy at various skill levels (capacity building)

- To foster research activities in renewable energy among African scientists working within Africa and those in the diaspora as well as non African scientists directly involved in training and education of African students and experts (capacity building)

- To promote and encourage the use of renewable energy in Africa (economy, development and environmental protection)

The structure of ANSOLE, its services (dissemination of renewable energy related information, students exchange fellowship programmes, organization of meetings in Africa, mediation in research and business activities, etc), its short and long terms objectives are the subject of this presentation.

Keywords: ANSOLE, Capacity building, renewable energy, students exchange programmes


Photovoltaic implementation in Chad. An overview

Yacoub Idriss Halawlaw1,2

1Faculty of Pure and Applied Science (FSEA in French), University of N’Djamena2Laboratory of Studies and research on Local Materials (LERM)

Chad being an oil producing country, it seems at first glance that photovoltaic is not interesting since we can produce energy without recourse to solar energy. But this is a superficial point of view, for oil reserves may be soon exhausted. So the governement of Chad has laounched many projects in implementing Photovoltaic plants, in street lights, water pumping devices.

This is a step of innovation. To succed, it must gather the maximum number of allies.

We intend to make an overview of these projects and analyze their liability and chances of success. We furthermore make projections in the future of such systems

Keywords: Photovoltaic plants, solar energy, innovation, Chad, technology transfer, implementation, sociotechnical analysis


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Solar Energy R&D Landscape and Solar Energy Roadmap of South Africa

Maaza Malik1,2

1UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk ridge, POBox 392, Pretoria-South Africa

2Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure road, Somerset West 7129, POBox 722, Somerset West, Western Cape Province, South Africa.

Summary

Although South Africa has very good solar and wind resources the deployment of renewable energy technologies has been slow to take off. More than 90% of South Africa’s electricity is generated from the burning of coal. Eskom, South Africa’s state-owned utility, has 27 operational stations in South Africa that make up 40.7 GW of the country’s capacity. Additional capacity is from imports and

independent power producers, resulting in a total capacity of about 43.5 GW, which aims to supply the forecasted peak demand of 36 GW.

South Africa receives some of the highest annual irradiation globally. Various solar resource assessments for South Africa indicate that the Northern Cape Province has the highest solar resource in the country. The annual radiation measures from the best sites in the Northern Cape are more than 30% higher than for the best sites in Spain. Upington, for example, has more than 6.5 kWh/m2 daily average global horizontal irradiation. Accordingly, the Department of Energy has established a target for renewable energy production at 10,000 GWh by December 2013. According to the draft National Integrated Resource Plan for Electricity 6,000 GWh of this target is expected from on-grid electricity

generation. Within the context of the South African Solar Energy Technology roadmap, the focus is geared towards 4 sub-sectors: (i) solar photovoltaic’s (incorporating PV and CPV), (ii) concentrated solar power (CSP), (iii) solar heating and cooling with a particular emphasis on solar water heating also referred as solar thermal, and (iv) high temperature solar energy.

This contribution reports on the South African solar energy plan and highlights typical R&D in solar energy within the South African landscape with a focus on the so called “Northern Cape Solar Park Corridor”.

Keywords: Renewables, Solar energy, South Africa.


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Solar Cooker Integrated with Nano-Composite Phase Change Material

Eswaramoothy MuthusamyDepartment of Mechanical Engineering, Vimal Jyothi Engineering College, Chemperi, Kannur-670632.

Kerala, India

This paper communicates the techno-economic analysis of solar cooker integrated with nano-composite phase change materials. The V – trough solar cooker is proposed to capture the solar radiation and concentrated on the selective receiver surface. The bottom of receiver unit is physically attached by encapsulated phase change materials consists of 5% Al2O3 with paraffin wax by weight. The standard thermo-physical properties of nano-composite materials; thermal properties of receiver unit; V trough concentrator are selected to solve its technical feasibility using steady state energy balance equations and different solar radiation values and atmospheric temperatures. The overall efficiency of the proposed system is obtained higher than solar box cooker with phase change material. The simple economic analysis illustrate that this proposed system could be financially viable and physically useful

Keywords: V trough concentrator, Solar cooker, Nano-composite materials, overall efficiency, economic analysis


Improving the Sustainability of Solar Thermal Electric Systems

Roman AdinbergSolar Energy Research Facilities Unit, Weizmann Institute of Science, Rehovot, Israel

Solar thermal storage and fossil fuel hybridization are used to stabilize power delivery and prolong the daily operating cycle of solar thermal power plants. The annual solar capacity factor (briefly, solar fraction) of commercial-scale hybrid power plants employing the state-of-the-art thermal storage systems with a nominal capacity within 10 full load operating hours is below 40%, so that most of the energy is derived from fossil sources.

The present study is concerned with evaluating the effect of thermal storage on the overall power system performance aimed at significantly increased solar fractions than that typically reported for the commercial parabolic trough plants.

The modeling and simulation results of this work show that improved sustainability of a hybrid solar thermal power plant resulted from a much higher solar fraction can be achieved by appropriate adjustment of the solar collector size and the thermal storage capacity without the need to change the power block capacity.

Particularly considered is a typical 50 MW parabolic trough plant having integrated a thermal storage module of 7.5 h capacity that is designed for base load operation in the hybrid mode with a solar fraction of 37%. Doubling both the solar collector size and the thermal storage capacity leads to the increase of the solar fraction value up to 65%. As compared to the reference power plant, the modified system requires an additional investment of 66% that according to the present estimates could be offset in a few years due to the significantly reduced consumption of fossil fuels.

Keywords: Solar thermal, energy storage, power plants


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Invited Lecture / 16:50-17:10 / Hall 2 Surveys and Examples

The Solar Energy Conversion for Developing Countries: The Case of Morocco

Izeddine Zorkani 1, Souad Maliani 1, Sanae Janati Edrissi 1, Anouar Jorio 1, Khalid Bouziane 2

1Faculté des Sciences Dhar E1 Mehraz, B. P. 1796, Fes, Morocco2Université Internationale de Rabat, Rabat, Morocco.

This paper reviews the uses of solar energy, and examines its impact on society and the environment. The Photovoltaic conversion is discussed; we will give a detailed description of different Photovoltaic technologies; the objective is to reduce the cost of solar cells with very high efficiency (> 30%). Recommendations on increasing the use of solar energy in sunbelt countries are discussed; special studies for the case of Morocco will be presented. An estimate will be given to demonstrate the advantages of the use of solar power within Morocco. As part of its strategy towards energy use, Morocco gives priority to developing renewable energy and sustainable development. The Moroccan Project of Solar Energy aims the establishment in 2020 with a capacity of electricity production from solar energy with a total capacity of 2000 MW; the PSM will be presented.

Keywords: Solar Enery, Photovoltaic, Moroccan Project of Solar Energy

Invited Lecture / 17:10-17:30 / Hall 2 Surveys and Examples

Global problems require collaborative solutions

David FaimanBen-Gurion University of the Negev Sede Boqer Campus, 84990 Israel

The paper first draws attention to the fact that science is based on absolute truth, whereas political disputes in general and wars in particular are based on differing interpretations of facts. It has been observed that scientists of radically different political opinions can nevertheless work together successfully on common scientific problems, as was demonstrated by Soviet and Western physicists during the Cold War. Thus, scientific problems can provide a common platform for enabling scientists of differing political persuasions to work together with mutual respect. The second observation in the paper is that Global CO2 production is currently in the vicinity of 400 ppm and rising at a rate in excess of 2 ppm per year. This coincides with approximately one-third of the annual emissions from fossil fuel consumption. The world accordingly needs, desperately, to reduce its use of fossil fuel. In order for solar energy to level off just the electrical part, which is rising at a rate in excess of 700 TWh per year, it would be necessary to install PV plants at the rate of almost 500 GWp of new generating capacity each year. The lecture will argue that such a program is technologically feasible, both regarding land requirements and cell availability - if Concentrator Photovoltaics is used for supplementing the current annual production rate of PV panels. However, it will require international cooperation and collaboration on a scale that has never been attempted. Such cooperation could sow the seeds of a novel World Peace Initiative.

Keywords: Global problems require collaborative solutions

KUTEM is an energy research center established in 2012 at Koç University by funds from TÜPRAŞ. The center constitutes of around 30 faculty members in Engineering, Sciences and Administrative Science & Economics. Research projects are carried out in a newly constructed state-of-the-art laboratory, as well in research laboratories of the affiliated faculty. The research activities of the center are focused on development of new energy technologies in areas which are fossil fuels, biofuels and solar fuels.

Please come and join us as research scientists or Ph.D. students to make our planet a better place by developing environmentally friendly and efficient energy technologies (kutem.ku.edu.tr).

ORAL PRESENTATIONS

SUNDAY18TH OF AUGUST

Sunday, 18th of August

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Heisenberg Uncertainty Principle in Bulk Heterojunction Solar Cells

Alan J.Heeger

Loren Kaake and Daniel MosesUniversity ofCalifornia, Santa Barbara, CA 93106

I will describe the discovery of ultrafast photoinduced electron transfer as the scientific foundation for the creation of a technology for low cost “plastic” solar cells. This initial charge separation occurs at a time scale two orders of magnitude faster than the first step in photo-synthesis in green plants.

We demonstrate by a series oftransient absorption measurements that the Uncertainty Principle can enable ultrafast (< 100 fs) charge transfer over distances of 10-20 nm in the nanoscopically textured material in bulk heterojunction solar cells. Because the spatial extent of the initially photoexcitated wavefunction is determined by the Uncertainty Principle, not by the eigenfunctions of the Schroedinger equation describing the disordered nanostructured material, we expect the emergence of new physics in nanoscience .

I will focus on the details ofthe operating mechanism; the origin ofthe open circuit voltage (Voc), the roJe of morphology on the charge separation and charge collection at the electrodes, the need for charge selective buffer layers and the origin ofthe limitations on the fill factor (FF). I will emphasize the importance ofthe competition between sweep-out and recombination and on studies ofrecombination mechanisms in BHJ solar cells.

Recent results on BHJ solar cells using small molecule donors (rather than polymers) will be briefly summarized.


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Preventing Energy Conflicts in Energy Landscapes: Peace and Security in the Renewable Energy Transformation

Jürgen Scheffran

University of Hamburg, Germany

In many of the world’s conflicts energy resources have been an influential factor. This is partly due to the dual nature of energy: while energy use is important for human life and society, a precondition for social development and economic prosperity, it may also cause risk, destruction and death. Physical power from energy can be converted into political power, and physical force is a tool used in violent acts. Traditionally, energy security has been framed in terms of ensured access to energy resources to meet political and economic goals, while the lack of energy is perceived as a security threat. Security risks and conflicts can also result from the use and misuse of energy, its side-effects and unbalanced distribution. In turn, violent conflicts and social disruption impede access to energy resources. Each component of the energy system can become a target of attack or resistance by state and non-state actors, including dams, reactors and power grids. On the other hand, energy use as well as the prevention of risks and conflicts is a field for international cooperation and global security.

Energy security strongly depends on its geographical and geopolitical context. The components of the fossil-nuclear energy system – coal, oil and natural gas reserves, uranium mines as well as the connecting infrastructures, networks and transportation routes – have shaped the global conflict landscape in the past century. Geopolitical conflict lines may become sharper with growing energy demand, diminishing fossil fuel reserves, uneven distribution of energy resources and increasing North-South imbalances. Fossil energy use also affects the environment in many parts of the world. While most of these impacts are local or regional, global warming caused by greenhouse gas emissions raises concerns about global security risks which are interconnected with regional and local conflict constellations. Nuclear energy poses a range of safety and security issues.

Growing concerns about energy security and climate change have increased interest in renewable energy from wind, hydro, solar, geothermal or bioenergy sources for meeting the society’s electricity, heating and fuel needs. The proposed transformation from fossil fuels to renewable energy sources requires large areas of land and infrastructure, creating new forms of “energy landscapes”. While renewables may have environmental impacts which are largely local and conflict with other land uses, transnational cooperation contributes to technology-transfer, new economic options and development perspectives. A sustainable energy transition seeks to develop environmentally responsible and economically efficient land-use paths.

Small-scale, decentral use of solar energy is widely accepted among citizens. Large-scale solar networks offer opportunities for cooperation between developed and developing countries. This includes power grids between Europe and Africa across the Mediterranean to develop the solar potentials of deserts in North Africa and the Middle East. Other renewable energy systems have specific impacts on the local environment and attract criticism but no major conflicts yet. The conflict potential of renewable energy sources has to be compared to the substantial security risks and conflicts of fossil and nuclear energy sources. To avoid conflicts of large-scale renewable expansion, criteria are developed for economic viability, environmental sustainability, social acceptability and political stability that strengthen security, development opportunities, climate adaptation and capacity building for the local population. To develop the peace potential of renewables and achieve the transformation towards a low-carbon society, energy pathways need to be systematically assessed and compared regarding benefits, costs, risks and conflicts. Mechanisms to support this process include strengthening of public acceptance, mediation and conflict resolution, stakeholder dialogues and participatory decisionmaking. Then there is a chance that the geographies of violence and conflict can be transformed into landscapes of peace and cooperation.

Keywords: Preventing Energy Conflicts in Energy Landscapes: Peace and Security in the Renewable Energy Transformation

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Invited Lecture / 09:30-09:50 / Hall 1 Photonics and Spectroscopy I

The Benefit of Tuning of Electronic Properties in IV–VI Colloidal Nanostructures by Alloy Composition and Architecture, for

Solar Energy Applications

Efrat LifshitzSchulich Faculty of Chemistry, Russell Berrie Nanotechnology Institute, Solid State Institute, Technion-

Israel Institute of Technology, Haifa 32000, Israel

IV–VI (PbTe, PbSe, PbS) colloidal nanostructures, such as quantum dots (QDs) and quantum rods (QRs), are the focus of widespread scientific and technological interest.Theyexhibit a size-tunable energyband-gapin the range of 0.3-1.7 eV, with the broad band absorption profile ranging from near-infrared (NIR) to thevisible range, thus enabling a harvest of a wide spectral window with a substantial benefit in photovoltaic cells. Simple pure nanostructure still exhibit some drawbacks, related to photo-stability at ambient conditions as well as fast relaxation processes (e.g., Auger process, trapping) that reduces the carriers concentration.

Thiswork discusses the formation of PbSe cores covered by another IV-VI semiconductor shell, i.e.,PbS. The shell coverage render the overall heterostructure with chemical stability, as well as induces new physical properties, depending on the core-to-shell band-edge offset, which leads to the generation of either type-Iheterostructures(when the conduction and valence bandsof the shell wrap those of the core) or type-IIheterostructures(when the band-edge of the constituents have staggered alignment). Type-I heterostructures confine the carriers mainly into the core regime, while type-II allocate one carrier in the shell and retain the second carrier within the core. In intermediate alignment, so-called quasi-type-II permits delocalization of one carrier over the entire core/shell structure. Fig. 1 shows a schematic drawing of the different heterostructures (top row) and their anticipated band-edge alignment with the carrier’s distribution curves (bottom row).

Type-II and quasi-type-II induce partial charge separation, influencing the strength of a direct Coulomb and exchange interactions, with immediate change of the radiative lifetime of a single and multiple excitons and theirexcitonbright to dark energy split.

Our workshowed the advantage of alloying in core/shell heterostructuresintegrated either in the core or within the shell constituents. For example, the presence of alloying in PbSe/PbSexS1-xor PbSexS1-x/PbS provides the QDs anf QRs with considerable chemical and photo-chemical stability.An epitaxially grown PbS or PbSexS1-x shell has an extremely small crystallographic mismatch (<=3%) with thePbSe cores,eliminating core/shell interface defects.We recently published theoretical and experimental work exploring the properties of PbSexS1-x and PbSexS1-x/PbSeyS1-y(0<=x(y)<=1) alloyed colloidal QDs, showingthe variability of the electronic properties with the element composition, as well as modification of exciton-phonon interaction, direct Coulomb and exchange interaction, whenever alloy composition was involved.

The experimental evidences, utilizing continuous wave and transient photoluminescence spectra recorded at various temperatures, revealed that the discussed alloyed heterostructures show exceptionally high emission quantum yield, chemical and photochemical stability, energy band-edge temperature stability, alleviating dark-bright splitting by exchange or/and valley-valley interactions, relatively longradiative lifetimes, all in comparison with the properties of primary PbSe core structures. The results reflect the uniqueness of the electronic properties of the heterostructures, controlled by shell width and alloyed composition. For examples, a tunnability of the band-gap energy by composition and architecture is shown in Fig. 2. Such a tuning can be of significant importance when size tunnability


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is not permitted in solar cells structures with small porous materials, or demand for compact self-assembled QDs.

Keywords: The Benefit of Tuning of Electronic Properties in IV–VI Colloidal Nanostructures by Alloy Composition and Architecture, for Solar Energy Applications

Fig.1

Schematic representationof the different core/shell heterostructures (top row) and illustration of the correspondingelectron and hole wave function distributions (bottom row).

Fig.2

Fig. 2.Variation of the ground-state exciton energy, Eg, versus (a) core radius (Rc) and shell thickness (W) in PbSe/PbS QD heterostructures, and (b) shell thickness (W) and composition (x) in PbSe/PbSexS1-x core/alloyed-shell QD heterostructures with Rc=1.5 nm.


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Exciton Diffusion, Charge Separation and Morphology of Polymer:Fullerene Solar Cells

Gordon J Hedley 1, Alexander J Ward 1, Alexander Alekseev 2, Arvydas Ruseckas 1, Calvyn T Howells 1, Ifor D.W. Samuel 1

1Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews2Materials and Condensed Matter Physics, SUPA, School of Physics and Astronomy, University of

Glasgow

Exciton diffusion is a key step in the operation of organic solar cells. We have been developing time-resolved fluorescence based methods for its study using processes such as volume quenching, exciton-exciton annihilation and surface quenching. We compare and contrast these different approaches to the measurement of exciton diffusion and apply them to a range of conjugated polymers and fullerenes. For volume quenching, in which the effect of a low concentration of quencher is used to study exciton diffusion, we separate contributions from energy transfer and diffusion to an interface.

Once exciton diffusion is known it can be used to probe blend morphology. We show this in a blend of the low bandgap polymer PTB7 and the fullerene PC71BM which gives a very high single layer efficiency of 9.2%[1]. We measure ultrafast fluorescence, and nanoscale photocurrent mapping to give a comprehensive study of the dynamics of exciton dissociation into charge carriers, nanoscale morphology and device performance of this high performance blend.

We find that the morphology consists of elongated fullerene-rich and polymer-rich fibre-like domains which are 10-50 nm wide and 200-400 nm long. These elongated domains are embedded in a mixed-phase of the two materials and provide a concentration gradient for directional charge diffusion. Our results suggest that the formation of narrow and elongated domains is desirable in bulk heterojunction solar cells and give insight into the role of solvent additives.

References: [1] Z. He, C. Zhong, S. Su, M. Xu, H. Wu, Y. Cao, Nature Photonics, 2012, 6, 591.

Keywords: organic, photovoltaic, photophysics, morphology


Magneto-photo-current of charge transfer complex in organic blends for photo-voltaic applications

Eitan EhrenfreundPhysics Department, Technion-Israel Institute of Technology, Haifa, Israel

Charge transfer complex states, from which pairs of positive and negative charges can either recombine or dissociate, are one of the main factors controlling the efficiency of bulk hetero-junction organic photo-voltaic (BHJ-OPV) cells. The room-temperature magneto-photocurrent magnetic field dependent response of BHJ-OPV cells is characterized by (a) non-saturating broad (>1 T) component

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with morphology dependent concave/convex profile, and (b) device dependent narrow (~0.01 T) component. This is unlike magneto-conductance or magneto-electro-luminescence in organic devices, where the response is quite narrow (<10-20 mT) having a nearly Lorentzian profile. We attribute the observed broad magneto-photocurrent to short lived charge transfer states where spin mixing is caused by the difference Δg of the donor/acceptor g factors; a mechanism that is more effective at high magnetic fields. We further show that dispersive decay mechanism with a wide distribution of characteristic decay times gives rise to concave/convex transformation as the decay becomes more dispersive.

Keywords: Magneto-photo-current of charge transfer complex in organic blends for photo-voltaic applications

Oral Presentation - 7 / 10:25-10:40 / Hall 1 Photonics and Spectroscopy I

Electronics and Photonics two science in the benefit of solar energy conversion

Mihaela Girtan1 Photonics Laboratory, Angers University, France

This paper gives a personal global point of view on two sciences: electronics and photonics towards plasmonics and solar energy conversion. The new research directions in these two sciences are pointed out by comparison and in the perspective of future new solar devices. A parallel and the equivalence between electronics and photonics are presented. Starting from electron in electronics, photon, solitons and plasmons in photonics, electrical cables - optical fibers, plasmonic wave guides, electrical circuits - optical circuits, electrical transistors - optical transistors, plasmonster, electrical generators - pulsed lasers and spasers, photonics gets step by step all the tools already existing in electronics. Solar energy could be converted in many ways, the most known is the conversion in electricity. Today we need that the energy is in form of electricity because most of the apparatus that we use are based on electricity: informatics, motors, etc. However, the progress in photonics with optical circuits, optical transistors etc., shows that the photonics informatics could be possible. Also the optical manipulation and optical engines concept were already demonstrated experimentally. If the laser propulsion will be achieved, and the optical engines will work, the question that will rise tomorrow is: “Shall we still use the electricity in the future? What will be the solar devices tomorrow?”

Keywords: plasmonics, solar energy, solar cells, photonics


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Advanced Pulse EPR/Moessbauer Spectroscopy and DFT Investigations of Hydrogen Producing Bioinpired Model

Complexes

Özlen F Erdem 1, Edward J. Reijerse 1, Sascha Ott 2, Marcetta Y. Darensbourg 3, Wolfgang Lubitz 1

1Max-Planck-Institute for Chemical Energy Conversion, 45470, Muelheim an der Ruhr2The Ångström Laboratory, 75120, Uppsala, Sweden3Texas A&M University, 77843, College Station, USA

[FeFe] hydrogenases are the most active enzymes in hydrogen conversion. Their active site contains a [2Fe]-subcluster coordinated by CO and CN ligands, as well as a bridging aza-dithiolate. This sub-site is taken as model for the development of inorganic hydrogen conversion catalysts with low over-potentials and mild acidic conditions. Investigation of such model compounds by means of advanced EPR spectroscopy along with the corresponding DFT studies enables to identify how the spin density is distributed over the irons and which role the various components play in the stabilization of the compound in the different states of the catalytic cycle. In this presentation several examples of EPR studies will be shown for various model compounds in Hox and Hox-CO states. For Hox models we observed that most spin density is localized on the distal Fe, whereas for Hox-CO models, it is delocalized over both irons. By means of e.g. orientation-selective 31P ENDOR, 11B HYSCORE we showed that ligand contributions can be distinguished: The diphenyl groups carry most of the spin density and therefore help to stabilize the compound in its [FeIFeII] state. The contribution of the caborane units are found to be mostly steric. Overall, the detailed EPR investigations supported by DFT analysis provide important information about how to construct such model compounds with a high efficiency under mild conditions that will help to develop better catalysts.

Keywords: EPR, Moessbauer, DFT, Hydrogenase, Spectroscopy, Catalyst


Insights on the interface composition in polymer:fullerene Organic Photovoltaics by sophisticated optical sensing

Stergios Logothetidis, Panagiotis G Karagiannidis, Argiris Laskarakis, Despoina Georgiou, Maria Seitanidou

Lab for Thin Films, Nanosystems & Nanometrology (LTFN), Physics Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece

Organic photovoltaics (OPV) are an emerging new technology which is expected to have a significant impact in the generation of electricity from renewable resources. Although novel low band gap materials resulted to power conversion efficiencies of up to 10%, a major research target is the control of the photoactive blend morphology.


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In this work, we investigate the interfacial composition in bulk heterojunction (BHJ) OPVs using polythiophene (P3HT) or polycarbazole derivatives (PCDTBT and Si-PCPDTBT) as electron donors, and fullerenes as electron acceptors. Thermal annealing was applied after the film deposition to increase crystallinity and blend phase separation and drive the quenched spin coated films to a more thermodynamically favorable state. The vertical distribution of donor and acceptor phases in the BHJ were investigated by Spectroscopic Ellipsometry (SE) working in the NIR-Vis-farUV spectral region.

The results show that the phase separation is interplay between crystallization and the incompatibility between the donor and acceptor, which result in segregation of the higher surface energy material to the highest surface energy interface. The above were correlated with the device electrical characteristics. These results reveal the importance of the buffer layers surface energy, which can be used to tune the blend vertical composition and furthermore the OPV performance.

Finally, we discuss the implementation of in-line SE for the robust investigation of the effect of the r2r process parameters on the composition and morphology of gravure printed OPVs.

Keywords: Spectroscopic Ellipsometry, morphology, bulk heterojunction, interfaces, in-line quality control


Effects of Ionizing Radiations on the Performances of CdS/CdTe Solar Cells

Stefan AntoheUniversity of Bucharest, Faculty of Physics, Bucharest, Romania

Photovoltaic cells based on CdS/CdTe thin films, produced by thermal vacuum sublimation, were irradiated with protons and alpha particles, at room temperature. The irradiation energy for both protons and alpha particles was 3 MeV and the fluencies were 1014 protons/cm2 and 1013 alpha particles/cm2, respectively. The prepared samples configuration was a ”superstrate” one having CdS as ”window” layer and CdTe as ”absorber” layer, respectively. The films were deposited by conventional thermal vacuum evaporation technique. The CdS/CdTe is given a post deposition CdCl2 heat treatment which enables grain enhancement, reduces the defect density in the films, promotes the interdiffusion of the CdTe and CdS layers and thereby improves solar cell efficiency. The effects of irradiation were studied by investigating the changes in the electrical and optical properties of the cells. The structures were electrical characterized before and after protons and alpha particles irradiation by measuring the I-V characteristics both in dark and in AM 1.5 conditions and the results were compared. The parameters characterizing a photovoltaic cell, short-circuit current, open circuit photovoltage and fill factor were calculated before and after protons and alpha particles irradiation and the obtained values are comparable, but less for irradiated samples. Moreover, the maximum power obtained for a photovoltaic cell half decreased after alpha particles irradiation. A discussion about the possible origin of those defects is given. In this sense, it was found that proton irradiation in the above mentioned conditions results mainly in the introduction of defects at the CdS/CdTe interface.

Keywords: CdS/CdTe Thin Films, Proton and Alpha Particles Irradiation


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Investigating the nature of charge carrier recombination in organic solar cells with intermodulation spectroscopy

Wolfgang Tress 1, Bergqvist Jonas 1, Tang Zheng 1, Ma Zaifei 1, Inganäs Olle 1, Forchheimer Daniel 2, Haviland David 2, Tholén Erik 3

1Biomolecular and Organic Electronics, IFM, Linköping University, 58183 Linköping, Sweden2Royal Institute of Technology (KTH), Section for Nanostructure Physics, Albanova University Center,

Stockholm SE-106 91, Sweden.3Intermodulation Products AB, Solna SE-169 58, Sweden

The optimum thickness of organic solar cells is limited by the strong dependence of the photocurrent on the electric field which results in a trade-off between the thickness required for large absorption and the fill factor required for high efficiency. There are two underlying phenomena which can explain this field-dependent photocurrent: Either the dissociation of (CT-)excitons depends on the applied field so that it competes with geminate recombination, or the charge carrier collection is inefficient so that free charge carriers are lost to so-called bimolecular recombination. The differentiation of these two fundamental processes is challenging.

We present a novel measurement method called Intermodulation Spectroscopy to directly identify bimolecular recombination with high sensitivity. The illumination intensity is modulated with two independent light sources, each at a slightly different frequency in the kHz regime. We collect the photocurrent response by lock-in measurement at these two frequencies and at their intermodulation products, e.g. sum and difference frequencies. When bimolecular recombination occurs, charge carriers induced from intensity modulation at difference frequencies encounter one another, giving rise to intermodulation, which alternatively can be viewed as a nonlinearity in the intensity vs. current relation. We sweep the whole current-voltage curve by applying a DC voltage while analyzing the intermodulation in the photocurrent. Analyzing the non-linear components of the photocurrent as a function of the linear response allows for a discrimination between geminate (linear) and bimolecular (nonlinear) processes. Investigating different devices we observe that the dominating process differs between the selected polymer:PCBM material systems and device architectures.

Keywords: organic solar cell, recombination, non-linearity


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Developing an Artificial Photosynthetic Reaction Centre

David Leslie Officer 1, Pawel Wagner 1, Klaudia Wagner 1, Nicholas Roach 1, Rhys Mitchell 1, Christopher Hobbs 1, Goutham Kodali 2, P. Leslie Dutton 2

1ARC Centre of Excellence for Electromaterials Science and the Intelligent Polymer Research Institute, University of Wollongong, Wollongong, Australia

2University of Pennsylvania, Perelman School of Medicine, Stellar-Chance Labs, Suite 1005, 422 Curie Boulevard, Philadelphia, PA 19104-6059, USA

The emulation of photosynthesis, the efficient and sustainable utilization of solar energy using renewable materials to produce hydrogen and oxygen from water or convert carbon dioxide into a chemical feedstock represents one of the great scientific challenges of the 21st Century. Replication of just one of the photosynthetic processes, light harvesting by chlorophylls (natural porphyrins) and its application in solar cells, would clearly make a significant contribution to sustainable energy production on earth without major carbon dioxide production. It could also lay the foundation for sustainable hydrogen production as well as fuel and food production through carbon dioxide fixation.

Creating photosynthetic-like processes in devices could provide a new generation of economical photovoltaic devices and lead to sustainable hydrogen production through water splitting. For example, in the dye-sensitised solar cell (DSSC) or Grätzel photoelectrochemical cell, light is harvested using a large surface area of dye (that may be a chlorophyll-like molecule) bound to a mesoporous thin film of nanostructured titanium dioxide and, following charge separation and injection of an electron into the semiconductor, the oxidised dye is reduced by a redox mediator. This has often been likened to the light harvesting component of photosynthesis. The introduction of water into the DSSC could then lead to water oxidation by the photo-oxidised dye and subsequent photosynthetic-like oxygen production, assuming the use of suitable dyes.

We are investigating the introduction of water soluble porphyrins into protein maquettes as a first step towards the development of an artificial photosynthetic device.

Keywords: porphyrins, artificial photosynthesis, maquettes, solar cells, light harvesting

Invited Lecture / 09:30-09:50 / Hall 2 Synthesis of Materials II

Very Low Bandgap Conjugated Polymers for Organic Electronics

Fred Wudl, Rajiv Kumar, Jonathan Yuen, Mingfeng Wang, Toan PhoUCSB

The design and synthesis of donor-acceptor conjugated alternating copolymers with a bandgap lower than 0.6 eV will be presented. These polymers do not behave like “classical” conjugated polymers, particularly in regards to spectroelectrochemistry and magnetic resonance. A possible explanation for their unusual behavior will be discussed.

Keywords: Donor-Acceptor, co-polymers, conjugated polymers


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Design of small molecular donors for organic solar cells

Jean RoncaliGroup Linear Conjugated Systems, CNRS, Moltech Anjou, University of Angers, France

Organic solar cells (OSCs) offer the possibility to develop low-cost and lightweight sources of photovoltaic electrical energy by means of simple technologies with low environmental impact.

Until now, the most efficient OSCs have been based on heterojunctions formed at the interface between electron donor an electron acceptor materials. Whereas a large part of the OSCs developed so far have used soluble π-conjugated (co)polymers as donor material, the polydispersity inherent to polymers can result in problems related to the reproducibility of the synthesis, purification and hence composition and electronic properties of the donor material. This context has contributed to stimulate intensive research work focused on the development of donor materials based on perfectly structurally defined conjugated molecules.

During the past few years, a huge number of molecular donors have been synthesized and evaluated in OSCs. Although this research effort has generated important progress in device efficiency that is now comparable to that of polymer-based devices, many of these donors, especially those designed for solution-process are rather complex molecular structures of high molecular weight obtained by multi-step syntheses and rather low overall synthetic yield.

In this presentation the relationships between the molecular structure and the photovoltaic performances of various classes of donor materials based on push-pull molecules will be discussed. Special emphasis will be placed on the molecular design of materials combining structural simplicity, low molecular weight and synthetic accessibility, all factors that are believed to acquire a growing importance in the future context of industrial large-scale production of OSCs.

Keywords: Design of small molecular donors for organic solar cells


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Oral Presentation - 50 / 10:10-10:25 / Hall 2 Synthesis of Materials II

Characterization, Modeling and Performance Comparison of Organic Bulk Heterojunction Solar Cells Based on P3HT and

Anthracene-Containing PPE-PPV

Safae Aazou 1, Asmaa Ibral 2, Matthew S White 3, Martin Kaltenbrunner 4, Daniel A. M. Egbe 3, Allé Dioum 2, Niyazi Serdar Sariciftci 3, El Mahdi Assaid 2

1Laboratory for Solid State Physics, Interfaces and Nanostructures, Physics Department, Liège University, Liège, Belgium

2Laboratory of Instrumentation, Measure and Control, Physics Department, Chouaïb Doukkali University, El Jadida, B. P. 20 El Jadida Principale, Morocco

3Linz Institute for Organic Solar Cells (LIOS), Department of Physical Chemistry, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria

4Department of Soft Matter Physics, Johannes Kepler University, Altenbergerstrasse 69, 4040 Linz, Austria

In this article, a full comparative study of two different types of organic bulk heterojunction solar cells (OBHJ-SCs) is presented. The OBHJ-SC of the first type is fabricated with the commonly used polymer: poly(3-hexylthiophene) (P3HT). The second is based on a recently synthesized anthracene-containing poly(phenylene-ethynylene)-alt-poly(phenylene-vinylene) (PPE-PPV) bearing randomly distributed segments of octyloxy and segments of 2-ethylhexyloxy side chains and denoted AnE-PVstat. Solar cells are characterized in dark and under A.M. 1.5 illumination, and the incident photon conversion efficiencies (IPCE) of best cells are measured. An electronic circuit, containing photocurrent generator, non-ideal diode with its reverse saturation current and its ideality factor, series and shunt resistances, is chosen to model the fabricated solar cells. Different methods are used to determine each solar cell model physical parameters from the current–voltage characteristics. The AnE-PVstat based OBHJ-SC demonstrated an efficiency of around 4%, and the modeling parameters are reported for the first time. The performance and extracted parameters of the OBHJ-SCs based on the two materials are compared.

Keywords: Organic bulk heterojunction solar cell, model physical parameters, Parameters extraction methods, Lambert W function.


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Doped conjugated polymers as (transparent) electrodes for photovoltaic devices

Valerii M KobryanskiiP.N.Lebedev Physical Institute, Russian Academy of Sciences, Moscow, Russia

The development of new type of anodes and cathodes, as substitutes of currently used materials, is very important for grows of photovoltaic devices market.

In 1977 was shown that process of polyacetylene doping is accompanied by decreasing of absorption band in visual region an appearance of absorption band in near infrared field. Thus, in principle, polyacetylene film doped by electronic acceptors (donors) can be excellent transparent anode (cathode) for photovoltaic devices. Unfortunately standard polyacetylene films contain high concentration of defects. Defects lead to low stability, low mobility of charges and excitations, and high intensity of background absorption. Thus, at present, doped conjugated polymers do not used as electrodes for photovoltaic devices.

In this report the new types of transparent anodes and cathodes based on doped conjugated polymers are discussed. The highly-ordered and low-defect films and coatings of 100% trans-nanopolyacetilene were developed. Process is carried out without thermal treatment. Then, the proton doped films of trans-nanopolyacetylene were developed. The doped nanopolyacetylene films are characterized by optical window in the field 300–800 nm and optical absorption band in near IR field. They can be used as flexible plastic electrodes for development of OLED, OFET and organic solar cells.

Keywords: conjugated polymers, highly ordered, proton doped


Hydrogen-bonded conjugated molecules - changing design paradigms for organic conducting materials

Eric Glowacki, Mihai Irimia Vladu, Siegfried Bauer, Serdar SariciftciJohannes Kepler University

We report on our work concerning organic semiconducting molecules from the family of hydrogen-bonded pigments - inspired by natural chromophoric systems. These molecules are worldwide employed as pigments for inkjet toners, rugged outdoor paints, and cosmetics; they are already mass produced, cheap, and recognized for their stability and nontoxicity. These molecules have poor intramolecular conjugation, and thus fall outside of the accepted design rules for organic semiconducting compounds. Despite this, our results show that films of H-bonded pigments support air-stable ambipolar charge carrier transport with mobilities up to 2 cm2/Vs in organic field-effect transistors. We attribute the charge transport in these materials to the cooperative interactions between dye molecules mediated by H-bonding and π-stacking. Thus, molecules lacking intramolecular conjugation interact to produce


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an intermolecularly π-conjugated network. This communication will report our recent investigation of crystal structure and thin film formation of H-bonded pigments, and their effect on charge transport anisotropy in organic field effect transistors and diode devices. A particular emphasis will be put on the assessment of the structure-property relationships and solid-state packing of these materials.

Keywords: organic electronics, organic photovoltaics, materials chemistry


Isoindigo-based Polymers for High-Performance Solar Cells

Ergang Wang 1, Zaifei Ma 2, Mats Andersson 1, Olle Inganäs 2, Fengling Zhang 2

1Department of Chemical and Biological Engineering/Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden

2Biomolecular and Organic Electronics, IFM, Linköping University, SE-581 83 Linköping, Sweden

Polymer solar cells (PSCs) are promising sustainable solar energy converters, which are attracting more and more attention because of their unique advantages of low cost, light weight, and potential use in flexible devices. To further improve the efficiencies of PSCs for practical applications, it is necessary to develop new conjugated polymers with several merits including low band gap, appropriate HOMO and LUMO positions, high mobility, decent solubility. A facial method to design polymers with these merits is to combine electron-rich (donor) and electron-deficient (acceptor) groups as repeating units, forming internal donor-acceptor (D-A) structures.

Isoindigo is a symmetrical molecule consisting of two indolin-2-one units, which contribute towards its strong electron-withdrawing character.1 On the basis of the D-A structures, we take isoindigo groups as acceptor and carbazole, thiophene, bithiophene and benzo[1,2-b:4,5-b’]dithiophene as donor units, respectively, and then developed a series of D-A types polymers.[1-3] Their photophysical, electrochemical and PV properties were investigated. The best performance was achieved by solar cells based on PBDT-BTI:PC71BM with an efficiency of 7.3%, an open-circuit voltage of 0.72 V, a short-circuit current density of 14.96 mA cm-2 and a decent fill factor of 0.68 under illumination of AM 1.5G simulated solar light (100 mW cm–2). Further optimization is ongoing. The preliminary PV performance demonstrated the high promise of the easily accessible isoindigo groups as electron-deficient units in designing D-A polymers for efficient PSCs.

[1] Chem. Commun. 2011, 47, 4908.[2] J. Mater. Chem. 2012, 5, 2306.[3] J. Am. Chem. Soc. 2011, 133, 14244.

Keywords: polymer solar cells, conjugated polymers, polymer synthesis, solar energy, energy conversion


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A bio-inspired light-harvesting system derived from self-assembled metallochlorins inside nanochannels*

Kasim Ocakoglu 1, Ersan Harputlu 1, Evgeny Ostroumov 2, Chavdar Slavov 2, Alfred R. Holzwarth 2

1Advanced Technology Reseach&Application Center, Mersin University, Ciftlikkoy Campus, TR33343, Yenisehir, Mersin, Turkey.

2Max-Planck-Institut for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470, Mülheim an der Ruhr, Germany.

The development of an efficient light-harvesting system trapping solar energy efficiently for driving solar fuel generation, is a crucial step in designing an artificial photosynthetic device, the Artificial Leaf. We here report a novel nano-structured antenna unit made up of synthetic zinc chlorin (ZnChl) self-aggregates formed inside the nano-channels of a modified anodic aluminium oxide (AAO) nano template. This bio-mimetic artificial antenna unit is a solid-state unit that is much more stable than any of the previous self-assembled nanostructures formed in liquid phases. The AAO membrane containing the self-assembled BChl antenna in its nano-channels combines excellent optical transparency with high chemical and mechanical stability. In order to provide a favorable environment for the formation of supramolecular ZnChl aggregates in the nano-channels of the AAO membranes, the inner walls were coated with a sol-gel matrix forming an inner surface of long hydrophobic chains. We compared the properties of the artificial antenna formed by two different modified Zn-BChls, (ZnChl d and ZnChl-NH2). In order to allow a directed energy transfer processes in the nano-structured ZnChl aggregates, a layer of an energy acceptor unit, the (BPheo a), was applied to the surface of the antenna unit. The energy transfer was characterized by ultrafast fluorescence spectroscopy.

* This research has been financially supported by The Scientific and Technological Research Council of Turkey, TUBITAK (Grant: 110M803) in the framework of ESF-EUROCORES (EuroSolarFuels-10-FP-006) and by the program “Complex Materials: Cooperative Projects of the Natural, Engineering and Biosciences” of the Volkswagen Foundation (funding to ARH and HJMdG).

Keywords: Artificial leaf, photosynthetic device, zinc chlorins, self-assembly, chlorophyll, aggregation.

Chemical structures of zinc chlorin derivatives and the quencher, natural bacteriopheophytin a (BPheo a).

Schematic view of AAO nanotemplates impregnated with Zn chlorin aggregates.


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Colloidal CuZnSnSe1-xSx Nanocrystal Based Hybrid Solar Cells

Mahmut Kus1, Faruk Ozel2, Sumeyra Buyukcelebi2, Mustafa Ersoz3 Niyazi Serdar Sariciftci4

1Selcuk University, Department of Chemical Engineering, 42075, Konya, Turkey2Selcuk University, Advanced Technology Research and Application Center 42075, Konya, Turkey

3Selcuk University, Department of Chemistry, 42075, Konya, Turkey4Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University Linz, Physical Chemistry,

Altenberger Strasse 69, A-4040, Linz, Austria

CuZnSnSe1-xSx (CZTS) nanocrystals (NCs), have a great attention due to its possible application potential instead in pn junction solar cells. Moreover, Their solubility in commong solvents make them solution processable fabrication of thin film devices. In this work, we report synthesis of different colloidal kesterite nanocrystals and their performance in PCBM based bulk heterojunction solar cells. Crystal structures were investigated by XRD, TEM and SEM techniques. Electrochemistry and optical properties were determined with cyclic voltammetry and optic absorption spectroscopy. NC:PCBM bulk heterojunction solar cells were fabricated and characterized to optimize the best device concepts. The best perfomance was observed to be ITO/PEDOT:PSS/CZTS:PSCM blend (1:10)/Al concept that shows 280 µA/cm2 with 300 mV Voc and FF of 0.38. Conversion efficiency was calculated to be 0.03%. Although the efficiency is poor, we have to emphasize that all materials are solution processable and low cost. So these concepts must be investigated to improve the efficiency.

Figure 1. IV Characteristics of CZTS:PCBM solar cells

Acknowledgement: We thank to Selcuk University Scientific Research Council (BAP) for financial supports.


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Organic nanocrystals from latent pigments for environmentally-friendly and biocompatible electronics

Mykhailo Sytnyk 1, Sergii Yakunin 1, Eric Daniel Glowacki 2, Gundula Voss 2, Wolfgang Schöfberger 3, Dominik Kriegner 1, Julian Stangl 1, Rinaldo Trotta 1,

Sajjad Tollabimazraehno 4, Niyazi Serdar Sariciftci 2, Wolfgang Heiss 1

1Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Linz, Austria2Linz Institute for Organic Solar Cells, Johannes Kepler University Linz, Linz, Austria

3Institute of Inorganic Chemistry, Johannes Kepler University Linz, Linz, Austria4Zentrum für Oberflächen- und Nanoanalytik, Johannes Kepler University Linz, Linz, Austria

Colloidal nanocrystals from inorganic semiconductors are well-suited for applications such as bio-labelling and the development of solution processed optoelectronic devices, including photodetectors, light-emitting diodes and solar cells, with improved performances. A serious drawback of the colloidal nanocrystals is their potential toxicity, caused by elements such as Hg, Pb, and Cd, Te, Se and others, which are mandatory for the synthesis of semiconductor nanocrystals, but are extremely harmful for the biosphere.

Thus here we demonstrate a nontoxic alternative to the well-established inorganic nanocrystals. We have developed a synthesis of biocompatible and environmentally-friendly organic NCs which exhibit many beneficial properties on-par with inorganic counterparts. These organic nanocrystals are based on various industrial pigments, such as indigo, epindolidione, quinacridone, and phthalocyanine, which provide stable colloidal solutions. Importantly, tuning synthesis parameters can be used to achieve a wide range of optical properties in terms of different colours. Some of these nanocrystals are highly luminescent and many show excellent charge transport properties in solution-processed thin films. The synthesis is mediated by ligand molecules which are used to control the nanocrystals shape and conductivity in films. By making use of vitamin B2 as ligands, quinacridone nanocrystal photoconductors were fabricated with a high responsivity and external quantum efficiency (times photoconducting gain) with values up to 190 %. These devices are prepared on paper as substrate simply using a hair brush to produce eco-friendly photodetectors with excellent stability and they demonstrate the potential of these organic nanocrystals for light harvesting applications.

Keywords: nanocrystals, latent pigments, colloids, ligands, photodetectors


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Invited Lecture / 13:00-13:20 / Hall 1 Photovoltaic Materials and Devices I

Carrier relaxation through the manifold of localized states in conjugated polymer and small organic molecule BHJ systems

and its implication on photovoltaic device performance

Daniel MosesCenter for Polymers and Organic Solids University of California, Santa Barbara, California, 93106

(USA)

One of the factors that limit the power conversion efficiency is the presence of disorder-induced localized electronic states in the BHJ composite. Understanding and improving the charge carrier transport through the BHJ nanostructure is therefore crucial for the realization of high efficiency organic photovoltaic devices. We investigated the role of localizing traps in various BHJ systems made of conjugated polymers as well as small organic molecules using transient photoconductivity measurements. We also deliberately introduce well-defined electron traps into a PCDTBT:PC60BM BHJ and investigated their effect on the carrier transport in this system. Our studies reveal a thermally activated photoconductivity in the nanosecond time regime that could be correlated with carrier relaxation through the manifold of localized states, a process that determines the temporal dependence of the carrier mobility. We will compare the role of traps in the polymer- and the small molecule-based BHJ, and discuss the implications of both the density and the spectral profile of trap states on the performance of photovoltaic device performance.

Keywords: Carrier relaxation through the manifold of localized states in conjugated polymer and small organic molecule BHJ systems and its implication on photovoltaic device performance

Oral Presentation - 32 / 13:20-13:35 / Hall 1 Photovoltaic Materials and Devices I

Co-evaporated organic photovoltaics based on DSSC dye donor and fullerene acceptor

Xiaofeng WangROEL, Yamagata University

In this study, we demonstrated the use of an unsymmetrical donor-acceptor (D-A) type dye-sensitized solar cell (DSSC) dyes as the electron donor and fullerene C70 as the electron acceptor for bulk-heterojunction (BHJ) organic solar cells. The blend ratio and the thickness of the active layer of indolineC70 blend films were optimized, and solar cells based on these blend films give a maximum power-conversion efficiency (PCE) of 4.5% with a short-circuit current (Jsc) of 9.1 mA cm-2, an open-circuit voltage (Voc) of 0.89 V and a fill factor (FF) of 0.56 was achieved under AM 1.5G solar illumination (100 mW cm-2).

Keywords: organic photovoltaic; dye-sensitized solar cell; novel donor materials


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Oral Presentation - 181 / 13:35-13:50 / Hall 1 Photovoltaic Materials and Devices I

Small-molecule organic photovoltaic cells based on a squaraine dye

Guo Chen 1, Hisahiro Sasabe 1, Daisuke Yokoyama 1, Zhongqiang Wang 1, Xiaofeng Wang 1, Takeshi Sano 1, Ziruo Hong 2, Yang Yang 2, Junji Kido 1

1Department of Organic Device Engineering, Graduate School of Science and Engineering, Research Center for Organic Electronics (ROEL),Yamagata University, Japan

2Department of Materials Science and Engineering, University of California-Los Angeles, USA

Organic photovoltaics (OPVs) have shown great potential for making large-size, flexible and light-weight solar cell devices. A small-molecule organic dye 2,4-bis[4-(N,N-diisobutylamino)-2,6- dihydroxyphenyl] squaraine (DIB-SQ) shows promising properties for photovoltaic cells such as intense absorption in near infrared region (λmax = 700 nm) as solid thin film (Fig. 1a) and deep highest occupied molecular orbital (HOMO) energy level (‒5.3 eV). By using DIB-SQ as a donor material, we can expect large short circuit current density (Jsc), large open circuit voltage (Voc) and thus high power conversion efficiency (PCE) in OPV cell. In this work, we have investigated optical and electronic properties of DIB-SQ in details and explored varied cell architectures. As a result, over 6% of PCE has been achieved by employing a bulk heterojunction (BHJ) cell structure with co-evaporated DIB-SQ and C70 as an active layer (Fig. 1b).

Keywords: Small-molecule, organic photovoltaic cells, squaraine dye

Fig. 1

Fig. 1 (a) Molecular structure of DIB-SQ, and UV-visible absorption of 60 nm-thick DIB-SQ, C70 and DIB-SQ:C70 (1:5) films; (b) Current density-voltage characteristics of the optimized DIB-SQ:C70 BHJ cell under dark and 100 mW/cm2 (AM1.5G solar spectrum) illumination.


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Inorganic, Organic and Hybrid Solar Cells: How different are they?*

David Cahen, Pabita K. NayakDept. of Materials & Interfaces, Weizmann Inst. of Science, Rehovot, Israel 76100

While we know what are the solar cell efficiencies that we can hope to achieve for perfect single crystalline inorganic single crystal-based cells, as demonstrated by the recent results for GaAs p/n cells,1] applying the same criteria to other types of cells is pushing the Shockley – Queisser model “beyond its own limits“.

So, while nothing is wrong with the S-Q treatment, the question arises if, for the newer so-called 2nd and 3d generation cells, it tells the whole story. In other words, are the differences between cell types, that are easily gleaned from comparing S-Q - predicted, to actual performances, merely a matter of insufficient efforts or do basic scientific bounds, beyond those accepted today, exist? [2]

We argue that additional limits exist for newer types of solar cells, including Organic PhotoVoltaics (OPV), many mesoscopic cells and (some of) their siblings. The true hybrid organic-inorganic, perovskite-based cells are one of the notable exceptions, which we ascribe largely to their remarkably high degree of crystallinity. Most strikingly, for organic material-based cells, are the effects of disorder, static disorder, expressed via tail states, and dynamic disorder, apparent, because of the importance of vibronic states.[3]

This then leads to a challenge for hybrid solar cells, which by “virtue” of combining organic with crystalline inorganic materials, introduce the extra limits of pure organics: Can we find ways where the combination of desirable characteristics overcomes the extra limits? Here it is likely that focusing solely on the pure science may be insufficient and factors, related to ease, versatility and cost of fabrication, need to be included to meet the challenge.

* Work done in part in collaboration with A. Kahn (Princeton) and with J. Bisquert.

[1] E. Yablonovitch et al., The opto-electronic physics that broke the efficiency limit in solar cells Conf. Record 38th IEEE PVSC, art. no. 6317891, (2012) pp. 1556-1559

[2] P. K. Nayak et al., Assessing Possibilities & Limits for Solar Cells, Adv. Mater., 23 (2011) 2870-6 http://www.weizmann.ac.il/materials/Cahen/images/Solar_cell_data_01_Jan_2013.pdf (+update on that site)

[3] P. K. Nayak et al., Photovoltaic Efficiency Limits and Material Disorder, En. Env. Sci. 5 (2012) 6022 – 6039.

Keywords: Inorganic, Organic and Hybrid Solar Cells: How different are they


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Oxide absorber materials for All Oxide Photovoltaics

Koushik Majhi, Assaf Anderson, Hannah Noa Barad, Yaniv Bouhadana, Adam Ginsburg, David Keller, Benjamin Kupfer, Eli Rosh Hodesh, Sven Rühle, Klimentiy Shimanovich,

Arie ZabanInstitute for Nanotechnology & Advanced Materials, Bar Ilan University, Ramat Gan, 52900 Israel

Combinatorial synthesis in conjunction with high-throughput (HT) methods have been developed to synthesize novel thin-film absorber materials for low cost all oxide photovoltaics [1]. Most metal oxides (MOs) have a band gap in the UV part of the solar spectrum and it is the aim of the project to synthesize and identify novel multi-component MOs with a band gap at lower energies. Continuous compositional spreads of metal oxides were synthesized via pulsed laser deposition (PLD) and high Throughput techniques were used to study optical structural, optical and electrical properties as a function of composition. The optical transmission spectra of mixed multi-component metal oxides show enhanced light absorption in the visible range. The crystal structure as a function of composition was characterized using scanning XRD and Raman spectroscopy. Application of such light absorbers in PV devices show improved performance compared to the pure metal oxide components of the absorber.

Reference:

1. Rühle, S.; Anderson, A. Y.; Barad, H.-N.; Kupfer, B.; Bouhadana, Y.; Rosh-Hodesh, E.; Zaban, A. All-Oxide Photovoltaics. J. Phys. Chem. Lett. 2012,3, 3755–3764

Keywords: All-oxide photovoltaics, hetero-junction solar cell, optical band gap, high throughput, thin film solar cell, thickness gradient

Invited Lecture / 13:00-13:20 / Hall 2 Solar Fuels and Photochemistry I

Visible Light Semiconductor Photocatalysis for Chemical Solar Energy Utilization

Horst KischDepartment of Chemistry and Pharmacy, University of Erlangen-Nürnberg, Egerlandstr. 1, D-91058

Erlangen, Germany

Human life on earth is based on the solar conversion of water and carbon dioxide to oxygen and carbohydrates, known as photosynthesis. In that fantastic process the green leaf functions as a heterogeneous photocatalyst – it absorbs visible light and generates redox active surface centers through photoinduced charge-separation, followed by interfacial electron transfer (IFET) and subsequent C-C and O-O coupling reactions. As final result tons of organic matter and oxygen are produced, a real large scale organic synthesis process. Simple semiconductor powders suspended in a solution of substrates can mimic the initial steps of photosynthesis, namely charge separation and IFET. In spite of many literature reports claiming the usefulness of semiconductor photocatalysis for organic synthesis, a close inspection reveals that this is justified only in a very few cases. In general,


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formation of well-known compounds was evidenced by physical methods and no attempts were made for isolation on a preparative scale. Extremely rare are C-C coupling reactions. Contrary to this we have found a novel reaction type wherein two or more substrates are combined to one unique addition product. Examples are the reaction of olefins with 1,2-diazenes or imines and the

SC, Vis

R1-H + ArC(X)=NR2 -------------------> ArC(X)(R1) - N(H)R2

sulfoxidation of saturated hydrocarbons by sulfur dioxide and oxygen photocatalyzed by CdS and TiO2, respectively.1 In the lecture we will mention also a photofixation of dinitrogen. Finally, we shall speculate about the future use of semiconductor powders as artificial leafs for solar food production.

(1) H. Kisch, Angew. Chem. Int. Ed. 52(2013)812

Keywords: Visible Light Semiconductor Photocatalysis for Chemical Solar Energy Utilization

Oral Presentation - 14 / 13:20-13:35 / Hall 2 Solar Fuels and Photochemistry I

Photoelectrochemical Reduction of CO2 on Organic Semiconductor Photocathodes for a Sustainable Fuel

Production

Engelbert Portenkirchner, Dogukan Apaydin, Christina Enengl, Stefanie Schlager, Matthew White, Markus Scharber, Niyazi Serdar Sariciftci

Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University Linz , A-4040 Linz, Austria

Using the sunlight as energy source to directly reduce CO2 to higher hydrocarbons would be one of the most elegant solutions concerning a sustainable production of hydrocarbon fuels.

The electrochemical reduction of CO2 however requires a high potential of almost -2 V vs. NHE for a one electron process. By performing a two electron or proton coupled multi-electron CO2 reduction, this required potential can be lowered significantly.

In this work the photoelectrochemical CO2 reduction by a p-type organic semiconductor in combination with a molecular junction using Poly(3-hexylthiophen) (P3HT) and Re(bipy)(CO)3Cl is presented.

Investigation of the charge carrier generation and separation in the semiconductor, the heterogeneous charge transfer to the molecular electrocatalyst, homogeneous catalysis and finally product gas analysis were carried out.

As a reduction product CO is formed that can then be used in various reactors that are designed for the conversion of syngas (i.e. a mixture of CO and H2) into carbon-based fuels following the long-established Fischer-Tropsch (FT) process.

Keywords: CO2 reduction, photochemistry, electrochemistry, organic semiconductor, catalyst


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Oral Presentation - 71 / 13:35-13:50 / Hall 2 Solar Fuels and Photochemistry I

Conversion of CO2 to solar fuels with Microbial Electrolysis Cells

Anita Fuchsbauer, Lisa Puttinger, Marianne Haberbauer, Silvia MartinekPROFACTOR GmbH

To allow further growth of renewable energy supply like solar energy the storage possibilities of electricity need to be improved. Due to the high energy densities chemical energy carriers seem to be especially suitable if generated CO2 neutral.

Within the framework of the project REGSTORE a new innovative combination of electrochemical and biotechnological processes for storing regenerative electric energy under the usage of CO2 as C1 building material for solar fuels is developed. Microbial electrosynthesis has a great potential to directly produce easy and safe manageable energy carriers like alcohols, methane and organic acids from electricity and carbon dioxide. This can be achieved at ambient pressure and moderate temperatures. Here we present a set of experimental results on the screening of various microorganisms and discuss the challenges for this technology from a practical point of view. Several different acetogenic pure cultures and methanogenic mixed cultures were routinely grown on H2 and CO2 under strictly anaerobic conditions and selected for further usage in Microbial Electrolysis Cells (MECs) according to the product analysis. Different electrochemical MEC setups including one chamber and two chamber batch cells and a larger semi continuous MEC were established for short and long time characterization (including LSV and CV measurements). We will further present the results form 750 h operation of the semi continuous MEC. As main products acetate, butyrate and ethanol were detected

Keywords: microbial electrosynthesis, carbon dioxide, microbial electrolysis cell, energy storage, solar fuels


Solar Fuels – breakthrough innovation in the renewable energy industry

Reinhold PriewasserJohannes Kepler University, Linz, Austria

Towards a sustainable energy path the different kinds of biomass (solid, liquid, gaseous) as well as solar and wind energy take on increasing weight. Those energy sources however are facing certain limitations in their progress of implementation. Concerning the use of biomass for energy purposes, finite capacities of biologically productive areas become obvious. Those restrictions lead to a competing use of arable land between generating food, raw materials and energy production. On the other hand, in the case of solar and wind energy volatile availability, difficult storing and their grid-boundedness are the main problems of a progressing implementation. Here, assured and spatially independent energy supply is only possible by installing high-powered long distance networks and powerful back up systems.

Limitations of biomass energy as well as those of solar and wind energy use could be essentially


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mitigated by “Solar Fuels” or in a more common sense “E-Fuels”. These fuels are based on hydrogen, which is produced through solar or wind generated electricity and further synthesized with CO2 into energy-rich hydrocarbons. In contrast to hydrogen, only those energy products are totally compatible for the existing infrastructure of energy transportation and storage as well as for usual end user technologies.

The presentation focuses on the numerous advantages and benefits of thus chemically bound solar and wind energy considered from the technological, the socioeconomic as well as from the ecological point of view.

Keywords: renewable energy sources, radical innovation in solar energy use, Solar Fuels, Electricity toFuels


Design of Nanostructured Sodium Tantalum Oxides for Solar Water Splitting

Harun Tüysüz, Tobias GreweMax-Planck Institut für Kohlenforschung, Mülheim an der Ruhr, Germany

Current world energy consumption is mainly based on non-renewable fossil fuels and needs to be shifted to renewable energy sources because of eventual fossil energy supply depletion and climate change concerns due to carbon dioxide accumulation in the atmosphere. The production of hydrogen by photo- and electrochemical splitting of water is one of the most challenging aspects of alternative renewable clean energy. The material design is an emerging key for the fabrication of materials for various applications, in particularly in catalysis [1, 2]. Herein, we report on preparation of a series of surfactant-free nanostructured sodium tantalum oxide. By varying the reaction parameters, amorphous sodium tantalum oxide, crystalline NaTaO3, Na2Ta2O6 and composite oxides have been successfully prepared. In addition, the photocatalytic behaviors of the prepared materials were investigated for water splitting into hydrogen and oxygen. Unexpectedly, porous amorphous sodium tantalum oxide ( Figure 1a) ) showed much better catalytic activity over the crystalline one. The synthesized Na2Ta2O6 nanocrystals and composite oxides also indicated promising activity for overall water splitting without any co-catalyst in comparison to bulk NaTaO3 (Figure 1b). The highest hydrogen production rate has been obtained with the composite materials where a hetero-junction of the two sodium tantalum oxide phases were in presence of structure [3].

[1] H. Tüysüz, M. Comotti, F. Schüth, Chem. Commun., 2008, 4022.[2] H. Tüysüz, F. Schüth, Advances in Catalysis, 2012, 55, 127.[3] H. Tüysüz, C. Chan, Nano Energy, 2013, 2, 116.

Keywords: Solar Fuels, Solar Energy Conversion, Water Splitting, Hydrogen Production


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Figure 1

TEM image of porous amorphous sodium tantalum oxide (a), and their photocatalytic activity in solar water splitting (closed and open marks represent H2 and O2 evolution, respectively) in comparison to crystalline NaTaO3 (cal.600°C), and bulk NaTaO3-SS (b).

Invited Lecture / 15:00-15:20 / Hall 1 Photovoltaic Materials and Devices II

Investigation of Thin Films of Inorganic Semiconductors for Inverted Structure Hybrid Solar Cells

Serap Günes, Süreyya Aydin Yüksel, Sinem Türkoglu, Aren Yazmaciyan, Fatih OngülYildiz Technical University

Normal geometry of bulk heterojunction (BHJ) solar cells comprises of blend of an electron donor conjugated polymer and an electron acceptor fullerene derivative which is used as a photoactive layer sandwiched between a transparent metal electrode, generally, indium tin oxide (ITO) and a low work function metal, generally, aluminum (Al). In order to overcome the instability problems of normal geometry of BHJ solar cells, inverted device geometry is introduced.

Thin layers of solution processed titanium oxide or zinc oxide have been applied as interfacial layers in the inverted geometry. These materials absorb ultraviolet (UV) light and are transparent in the visible spectrum. New materials absorbing visible, red or infrared part of the solar spectrum, where the maximal photon flux of the sun is located, are off special interest. In this study, we investigated the effect of alternative thin films of inorganic semiconductors such as cadmium sulfide (CdS) or copper indium di sulfide (CuInS2) on the photovoltaic performance of the inverted structure hybrid solar cells. Thin films of inorganic semiconductors with different thicknesses were deposited using spray deposition technique. Current-voltage (I-V) characteristics were performed under dark and AM 1.5 illumination (mW/cm2) conditions. We achieved a power conversion efficiency of ca 0.3 % for the solar cells employing CdS.

Keywords: hybrid solar cells, inorganic semiconductors, inverted type solar cells


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Oral Presentation - 226 / 15:20-15:35 / Hall 1 Photovoltaic Materials and Devices II

Photodegradation effects in a polymer/fullerene organic solar cell

Tracey Clarke 1, Attila Mozer 1, Christoph Lungenschmied 2

1ARC Centre of Excellence for Electromaterials Science, Intelligent Polymer Research Institute, University of Wollongong, Innovation Campus, Squires Way, North Wollongong, NSW 2500, Australia

2Konarka Technologies, 116 John St., Suite 12, Lowell, Massachusetts 01852, USA

Even though efficiency records of organic solar cells based on blends of conjugated polymers and fullerene derivatives have been frequently broken over recent years, insufficient device lifetime may threaten the widespread commercial implementation of this versatile technology. With so much emphasis on increasing power conversion efficiencies, relatively little attention has been applied to the stability of such organic photovoltaic devices. This is a key issue and considerable research is required to investigate mechanisms of degradation and strategies to enhance device lifetime.

The photodegradation study here has been performed on encapsulated photovoltaic devices comprised of the novel silole-based donor-acceptor polymer KP115 blended with PCBM. Photodegradation induces an almost 20 % decrease in power conversion efficiency, primarily as a result of a reduction in short circuit current. The initial burn-in phase of the photodegradation has been examined using a combination of transient absorption spectroscopy and charge extraction measurements, including photo-CELIV (charge extraction by linearly increasing voltage) and time-resolved charge extraction using a nanosecond switch.

These measurements reveal a bimodal KP115 polaron population, comprised of both delocalised and localised/trapped charge carriers. The photodegradation results are consistent with an alteration of this bimodal KP115 polaron population, with the polarons becoming trapped in a broader, deeper density of localised states. The short circuit current therefore decreases after light soaking due to a reduction in the efficiency of trapped charge carrier extraction. Such research is one of the first steps in overcoming the photodegradation that is observed in so many polymer-based solar cells.

Keywords: photodegradation, transient absorption spectroscopy, charge extraction, charge carrier trapping


Growing Silicon nanowires from low cost metallurgical grade silicon powder with a simple electroless Ag assisted etching

method

Ouertani Rachid, Hamdi Abderrahman, Amri Chohdi, Khalifa Marouen, Bouaicha Mongi, Ezzaouia Hatem

Photovoltaic Laboratory Research and Technology Centre of Energy, Borj-Cedria Science and Technology Park, BP 95, 2050 Hammam-Lif, Tunisia.

In the past few years, several methods have been reported for synthesizing Silicon nanowires ( SiNWs). However, almost all of the SiNWs performed were made from substrates. In this work, we present the first results describing how we obtain SiNWs starting from metallurgical grade silicon powder and using a simple electroless but silver assisted etching method. The use of Si powder instead of Si wafers is intended to reduces significantly the cost of fabrication and increases the ease of fabrication. After


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beeing cleaned, filtered and dried, the Si particles were wrapped with Silver powder. The bright mixture of Si-Ag mixture is dipped in a HF:H2O2: H2O in different proportions. The etching duration varies from 10 to 90 minutes. MEB caracterization reveals that SiNWs intertwine and sometimes curl with lengths starting from 0,5 to 5 µm with an average diameters of 100 to 50 nm. Structural analyses shows that SiNWs are crystalline. Absorbance spectrum shows an edge near 1025 nm similar to SiNW grooved in Si wafer.

A slight blue shift of the absorbance in comparison with that of referenced bulk Silicon. The light emitted from the arrays upon laser irradiation is visible to the naked eye and appears orange to red in color much like the nanocrystalline in porous silicon. The photoluminescence (PL) spectrum shows a band centered at 680 nm. Finally SiNWs have been processed successfully using a low cost approach starting from cheap metallurgical Si powder and using a simple metal assisted electroless etching method.

Keywords: Silicon nanowire, electroless etching, Si powder, Ag assisted, PL


A novel technique for measuring carrier mobilities and the recombination coefficient in operational organic solar cells

Bronson Philippa 1, Ronald White 1, Almantas Pivrikas 2

1School of Engineering and Physical Sciences, James Cook University, Townsville 4811, Australia2School of Chemistry and Molecular Biosciences, Centre for Organic Photonics & Electronics (COPE),

The University of Queensland, Brisbane 4072, Australia

Transient experiments such as time of flight (ToF) and charge extraction by linearly increasing voltage (CELIV) are commonly used to characterise operational solar cells. Transport parameters such as carrier mobilities and the recombination coefficient can be obtained from these measurements. However, these techniques can be difficult to apply to operational devices made from high mobility materials. As the mobility increases, the transit time decreases, and the transit time can become comparable with the RC time of the measurement circuit, where R is the circuit resistance and C is the device capacitance. As a consequence, transport measurements on operational devices can be distorted by these “RC effects” and classical techniques can be inapplicable.

We utilise the resistance as a tool to probe carrier transport properties. By systematically varying the external circuit resistance, we develop a new technique for estimating the recombination coefficient and carrier mobilities. This technique is applicable to thin films manufactured from modern, high mobility organic semiconductor materials. We demonstrate it on operational bulk heterojunction organic solar cells.

Keywords: OPV, Mobility, Recombination



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Environmentally Friendly and Cost Effective Way to Produce Thin Film Solar Cells: Ultrasonic Spray Pyrolysis of CIGS/InS

Heterojunctions

Erkan Aydın, Esma Uğur, Nurdan Demirci SankırDepartment of Materials Science and Nanotechnology, TOBB University of Economics and

Technology, Ankara, Turkey

Ultrasonic spray pyrolysis (USP) is one of the most promising atmospheric condition manufacturing technique for the thin film solar cells. Advantages of this method include low solution consumption, very simple and therefore cost effective equipment, and tailorable thin film properties. In this study, copper indium gallium sulfide (CIGS) thin films have been deposited on glass by USP. CIGS, one of the chalcopyrite absorbers, offers unique advantages such as tailorable band gap, high efficiency and stability. Moreover, reduced toxicity compare to the selenium containing absorbers and variety of manufacturing techniques made this material very attractive for large area applications. We have controlled the morphological, structural, optical and electrical properties of the CIGS thin films by simply changing the precursor solution amount and the Ga/(In+Ga) ratio in the solution. Chalcopyrite structure of the films was confirmed by XRD analysis. High absorption coefficient values have been obtained for all samples. Band gap (Eg) of the films were around 1.50 eV, which is very close to the Eg of the bulk CIGS. After improving the physical properties of CIGS absorber layer, InS window layer has been deposited again via USP. According to our best knowledge this is the first report on CIGS/InS heterojunctions deposited by USP. We have investigated the junction properties of the CIGS/InS at room temperature. It has been observed that thickness of the InS layer dramatically affects the diode properties. Further information on the diode properties and possible cell configurations will be provided.

Keywords: Copper Indium Gallium Sulfide, Indium Sulfide, Heterojunction, Ultrasonic Spray Pyrolysis

Cross Section SEM of CIGS/InS Heterojunction


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Multifunctional application of CdS nanostructured layers in solar cells

Oleg Dimitriev 1, Dmytro Grynko 1, Olexander Fedoryak 1, Petro Smertenko 1, Nickolay Ogurtsov 2, Alexander Pud 2, Yuri Noskov 2, Ramesh Laghumavarapu 3,

Diana Huffaker 3

1V. Lashkaryov Institute of Semiconductor Physics, Kiev, Ukraine2Institute of Bioorganic Chemistry and Petrochemistry, Kiev, Ukraine

3University of California Los Angeles, Los Angeles, USA

We report on the development, application and comparison of CdS nanostructured layers in four domains of solar energy conversion, namely, in (i) nanocrystal – polymer cells, (ii) nanocrystal – dye solid cells, (iii) nanocrystal - bulk heterojunction (BHJ) of organic donor and acceptor compounds, and (iv) dye-sensitized electrochemical cells. The role of CdS layer in each of the above structures has been elucidated and the performance of the above solar cells has been compared. The CdS layers have been prepared by vapor-liquid-solid and vapor-solid condensation techniques on indium-tin oxide electrodes in the form of nanowire arrays and nano-textured films, respectively, which were then used as substrates for the formation of hybrid organic-inorganic solar cells. It has been found that CdS plays the active role as the acceptor in the first two types of solar cells, whereas it plays the role of an electron-transporting layer to rectify electron flow from the organic BHJ layer to anode in case (iii). By changing morphology of the CdS layer from textured continuous films to a nanowire arrays we demonstrate improved efficiency of collection of charge carriers due to the increased organic-CdS interface area. Bifunctional role of the CdS layer as a bottom electrode with high electron affinity and as a means to increase hybrid interface for better electron collection from the organic active layer has been demonstrated in cells of (i), (ii) and (iii) types. Electrochemical cells showed a more complex behavior, since both CdS and the adsorbed dye are light absorbing components their.

Keywords: CdS; organic dye; hybrid solar cell; photovoltaics; morphology; nanowire.


Interfacial degradation in organic solar cells

Ayse TurakDepartment of Engineering Physics, McMaster University, Hamilton, Canada

After efficiency, lifetime is the second most important parameter for molecular photovoltaic devices. In organic solar cells (OPVs), heterojunctions play a defining in device stability. They also control the major processes: charge separation relies on effective organic/organic interfaces; charge transport is critically determined by the structure of the thin film, controlled by the organic/inorganic interfaces with substrates; and charge extraction can only occur at high quality inorganic/organic interfaces at the electrodes.

This contribution reviews the current state of the art with regards to interfacial stability of electrode/active layer interfaces to understand the performance of OPVs. From examples relating to interfacial chemical reactions, interfacial morphological changes, and interfacial electronic level modification, a comprehensive picture of the role of the organic-electrode interfaces in device stability can be formed.


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Beginning with a brief overview of general degradation in organic devices, including definitions and measurement approaches, this contribution then focuses on two key interfaces within the device architecture. The first is the bottom contact (substrate) interface, where chemical reactions and dewetting are the two main mechanisms of device degradation. The second is the top contact interface, which is prone to oxidation, interdiffusion, blistering and delamination, and inhomogeneous loss of performance (dark spots). For both bottom and top contact interface degradation, various approaches to overcoming device instabilities are given, with special attention to the various interlayers that have been introduced for improved stability. Examples are given where degradation mechanisms are used advantageously to produce novel devices and surprising solutions to device degradation.

Keywords: organic photovoltaics, interfaces, degradation

Degradation


Transient photoresponse of PbS nanocrystals with inorganic ligands

Wolfgang Heiss 1, Sergii Yakunin 1, Mykhailo Sytnyk 1, Florian Hackl 1, Markus Humer 1, Thomas Fromherz 1, Sajjad Tollabimazraehno 2,

Loredana Protesescu 3, Dmitri Dirin 3, Marina V. Bodnarchuk 3, Maksym V. Kovalenko 3

1Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Linz, Austria2Center for Surface- and Nanoanalytics, Johannes Kepler University Linz, Linz, Austria

3Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH-Zürich, Zürich, Switzerland

Colloidal PbS nanocrystals are highly suitable for the development of light harvesting devices, due to their favorable band gap energy in the near infrared and their simple solution processability. In recent years continuous progress has been made in respect to responsivity and power conversion efficiency, first of all driven by the improved charge transport in nanocrystal films, which are treated by ligand exchange. While in most attempts the ligands are replaced during the layer-by-layer deposition of the nanocrystals, in this work the ligands are replaced already in solution, from organic oleic acid molecules to As2S3 inorganic complexes. Films form these nanocrystals exhibit photoconductivity with high responsivity of 200 A/W, corresponding to a product of external quantum efficiency times gain of 200. The key to this high photonconductive gain is the trapping of electrons after photoexcitation by defects, located closely below the conduction band. By a combination of transient photoluminescence, photoinduced absorbance and photoconductivity experiments the dynamics of carrier trapping and escape is revealed. Interestingly the decay of the transient photoconductivity, found on timescales of milliseconds, depends on the duration of illumination. This behavior is modeled by taking into account a trap state distribution function and a saturation behavior of trap filling. The measured trap states


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distribution function peaks approximately 60 meV below the conduction band edge. Since trap states effectively reduce the open circuit voltage of solar cells, the relative small value found in our system makes this material promising for photovoltaic device applications.

Keywords: nanocrystals, inorganic ligands, photoconductivity, trap states


Improved materials and device architectures for polymer solar cells

Rene A. J. JanssenEindhoven University of Technology, The Netherlands

The recent significant increase in power conversion efficiency (PCE) of polymer-fullerene solar cells largely originates from the successful development of new electron donor polymers. The donor-acceptor (D-A) or push-pull design, where electron rich and electron deficient units alternate along the copolymer chain is commonly used to tune the HOMO and LUMO energy levels and the optical band gap of these polymers. While structure-property relations for energy levels are well established, these are less clear for the actual photovoltaic performance. Creating morphologies in which nanometer-sized, interconnected, semi-crystalline domains of both polymer and fullerene exist seems crucial for high photovoltaic performance. These semi-crystalline domains optimize the conjugation along the polymer backbone and allow delocalizing the carrier wave functions to assist efficient charge separation. High molecular weight and a tendency to crystallize are important in achieving such morphologies.

For a range of diketopyrrolopyrrole-based small band gap polymers it will shown how the molecular weight of semiconducting polymers and the nanomorphology are crucial parameters in obtaining high power conversion efficiencies in the range of 6-8% for single junctions, with optical band gaps down to 1.3 eV. When the new semiconductor materials are combined with a wide band gap material it is possible to make create tandem and multi-junction devices in tandem or triple layer configurations with efficiencies close to 9%. The favorable efficiency of the tandem cell is achieved by an almost perfect complementarity of the absorption spectra of the different absorber layers that reduce thermalization losses. Because of their high voltages, triple junction solar cells can be used for photo-electrochemical water splitting.

The last part of the lecture will address our first attempts to predict bulk heterojunction morphologies that are obtained when casting polymer/fullerene blends from solution. The crucial role of the solvent will be highlighted.

Keywords: Improved materials and device architectures for polymer solar cells


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Invited Lecture / 15:00-15:20 / Hall 2 Solar Fuels and Photochemistry II

Towards highly efficient PbS nanocrystal solar cells

C. Piliego, S. Z. Bisri, M. J. Speirs, D. M. Balazs, Maria Antoniette LoiZernike Institute for Advanced Materials University of Groningen, Groningen, The Netherlands

Colloidal semiconductor nanocrystals (NCs) are solution processable semiconductors that because of their remarkably broad absorption, their large tunability, their high dielectric constant, and high stability under ambient conditions are highly appropriate for optoelectronic device fabrication. Recently, several authors have reported that the use of small conjugated ligands allows overcoming the dichotomy between quantum confinement and the necessity of electrical transport.

With a simple Schottky-like architecture and PbS NCs cross-linked with benzene-dithiols as active layer, power conversion efficiencies above 5% and fill factors of 60% under AM1.5 illumination are obtained [1, 2]. This record efficiency demonstrates that even by using the simplest device architecture, accurate post-synthetic treatments result in substantial improvements in the performance. By drawing a direct correlation between ligand-to-NC ratio in the starting PbS solution and the device parameters, we provide important insights on how to gain experimental control for the fabrication of efficient PbS solar cells. [2, 3]. At the end, I will discuss as PbS NCs together with conjugated polymers can give new possibility towards broad absorption of the solar spectrum.[4]

[1] K. Szendrei, W. Gomulya, M. Yarema, W. Heiss and M. A. Loi, Appl. Phys. Lett. 97, 203501 (2010).[2] C. Piliego, L. Protesescu, S. Z. Bisri, M. V. Kovalenko and M. A. Loi, Energy Environ. Sci. (in print).[3] K. Szendrei, M. Speirs, W. Gomulya, D. Jarzab, M. Manca, O. V. Mikhnenko, M. Yarema, B. J. Kooi, W. Heiss, and M. A. Loi, Adv. Funct. Mater. 22, 1598 (2012).[4] C. Piliego, M. Manca, R. Kroon, M. Yarema, K. Szendrei, M. Andersson, W. Heiss and M. A. Loi, J. Mater. Chem., J. Mater. Chem., 22, 24411 (2012).

Keywords: Towards highly efficient PbS nanocrystal solar cells

Oral Presentation - 267 / 15:20-15:35 / Hall 2 Solar Fuels and Photochemistry II

Easy Accessible Electrocatalytic Assemblies for Water Splitting and Solar Fuel

Khurram Saleem JoyaLeiden Institute of Chemistry, Leiden University, Einsteinweg 55, P.O. Box 9502, 2300 RA, Leiden, The

NetherlandsDepartment of Chemistry, University of Engineering and Technology (UET), GT Road, 54890, Lahore,

Punjab, Pakistan

In-situ formation of catalytic materials on conducting surfaces have immense applications in electrochemical and light-driven water splitting systems and solar fuel devices, but a simple and easy accessible route for developing surface-assembled catalysts under benign conditions (RT, pH=7) is yet to be demonstrated. We here disclose a very simple electrochemical approach to make electrocatalytic materials on electrode surface in a neutral pH system that can be efficiently employed for water


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oxidation, H2 generation and CO2 reduction system. The surface morphology, materials features and catalytic abilities of so generated electrocatalytic materials are identical to those generate by other methods, and catalytic performance of these surface-assemblies for water splitting is remarkable over a wide range of pH (pH 6-11). These electro-assembled catalysts are very efficient for H2/O2 evolution systems, and in combination with suitable CO2 reduction module at the cathode, they are able to generate liquid fuel (formic acid, methanol) from water.

Keywords: Artificial Photosynthesis, Water Splitting, Solar Fuels, Electrocatalysis, Surface-Assemblies


Structural and mechanistic studies of water oxidation catalyzed by cobalt oxide nanoparticles

Karolina Kwapien, Simone Piccinin, Stefano FabrisCNR-IOM DEMOCRITOS Simulation Center and SISSA, Via Bonomea 265, 34136 Trieste, Italy

Solar-driven water splitting is a key photochemical reaction in solar fuel production.[1] In nature, water oxidation occurs in Photosystem II. To mimic the function of this protein complex, an amorphous cobalt-phosphate catalyst (Co-Pi) has been recently reported to effectively promote water splitting.[2] However, the lack of the well-defined structural model of the Co-Pi catalyst prevents the understanding of the reaction mechanism.

We have recently proposed the first realistic models of these amorphous cobalt oxide nanoparticles.[3] The calculations show that the Co-Pi grains consist mostly of a disordered Co-O network with phosphate groups localized on their surface. The cubane Co4O4 motifs are formed at the surface of the amorphous grains and are considered to be responsible for water oxidation activity. Our predicted structures are in good agreement with X-ray Absorption Spectroscopy (XAS) measurements.[4]

In the present work we employ Car-Parrinello molecular dynamics and density functional theory to describe structure and catalytic activity of Co-Pi nanoparticles in water solution. We elucidate the role of the surface phosphate groups as proton acceptors and mediators in protonation of the neighboring oxygen ions. We perform a thermodynamic analysis of the main reaction steps relevant for water oxidation. Our simulations identify useful correlations between the reaction mechanism, thermodynamic efficiency and local structure of the active sites.

[1] N. S. Lewis et al. PNAS 2006, 103, 15729[2] M. W. Kanan et al. Science 2008, 321, 1072[3] X. L. Hu et al. ACSNano 2012, 6, 10497[4] M. W. Kanan et al. JACS 2010, 132, 13692

Keywords: artificial leaf, water splitting, Co-Pi


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Electrochemical reduction of CO2 with immobilized dehydrogenase enzymes

Stefanie Schlager, Daniela Hiemetsberger, Dogukan Hazar Apaydin, Engelbert Portenkirchner, Daniel Voglhuber, Niyazi Serdar Sariciftci

Linz Institute for Organic Solar Cells (LIOS), Institute of Physical Chemistry, Johannes Kepler University Linz, Austria

Enzymatic reduction reactions are well known from biological systems [1]. CO2 is reduced to formate, formaldehyde or methanol by formate dehydrogenase, formaldehyde dehydrogenase and alcohol dehydrogenase respectively with the aid of the coenzyme Nicotinamidadenin dinucleotide (NADH). We present the immobilization [2] of these enzymes in alginate based matrices for a sustainable, repeatable CO2 reduction. Different alginate containing gels were investigated for efficient CO2 conversion [3,4]. Further modification of the gels with PEDOT:PSS increases the conductivity of the material. This offers the opportunity for electrochemical application of the enzyme containing systems and therefore to substitute NADH as electron provider. Production of formate and methanol are shown for the enzymatic CO2 reduction in electrochemical and non-electrochemical experiments. Products were analysed in ion chromatography and gas chromatography. Conductivity of the PEDOT:PSS modified alginate gel was determined by four probe measurement. Electrochemical measurements were performed in a one compartment cell using alginate covered Pt as working electrode. Cyclic voltammograms were recorded for electrochemical characterisation. Results from CO2 saturated samples are compared to N2 purged setups to proof product generation from CO2 reduction.

[1] M. Aresta, A. Dibenedetto, Ref. Mol. Biotechnol., 90, 113-128(2002).[2] T. Reda, C. M. Plugge, N. J. Abram, J. Hirst, PNAS, 105, 10654-10658 (2008).[3] O. Heichal-Segal, S. Rapport, S. Braun, Nat. Biotechnol., 13, 798-800 (1995).[4] Y. Lu, Z.-Y. Jiang, S.-W. Xu, H. Wu, Catal. Today, 115, 263-268 (2006).

Keywords: enzyme, CO2 reduction, biocatalyst, immobilisation, electrochemistry


Increasing the Cost-effectiveness of Advanced Techniques of Treating Industrial Effluents by Means of Solar Cells

Azam Pirkarami, Mohammad Ebrahim OlyaDepartment of Environmental Research, Institute for Color Science and Technology, P. O. Box: 16765-

654, Tehran, Iran.

The organic materials lost in textile, leather, and plastic industries pose a major problem to water sources [1]. Over the years, many techniques have been proposed to treat industrial wastewater. However, these methods are not cost-effective because they consume too much electricity. This prompted us to subject some industrial effluents to four of the most commonly used techniques of treatment (electrocoagulation, photoelectrochemistry, photodegradation, and sonodegradation) [2,


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3]. We utilized solar cells as the source of electricity with the aim of increasing the cost-effectiveness of the methods of treatment. The operating parameters used in the experiments were current density, photocatalyst dose, contaminant concentration, pH, bias potential, temperature, and supporting electrolyte. To judge the efficiency of the processes, the COD (Chemical Oxygen Demand) and TOC (Total Organic Carbon) tests were used. The efficiency of the photocatalyst was studied using SEM and XRD techniques. The post-treatment products were also characterized using FT-IR, HPLC, and GC-MS techniques. Cost analysis was also performed, considering the costs of electrical energy, UV irradiation, electrode material, and electrolyte as major cost items. The results clearly demonstrate that the use of solar cells significantly lowers the costs associated with electricity consumption during the treatment.

Keywords: Cost-effectiveness, Solar Cells, wastewater

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Water-Soluble Chlorophyll Analogues For Red Light Driven Artificial Photosynthesis

Kerstin T. Oppelt 1, Canan Uslan 2, Behice Şebnem Sesalan 3, Günther Knör 1

1Institute of Inorganic Chemistry, Johannes Kepler University, 4040 Linz, Austria.2Institute of Inorganic Chemistry, Johannes Kepler University, 4040 Linz, Austria. /// Department of

Chemistry, Istanbul Technical University, Maslak3Department of Chemistry, Istanbul Technical University, Maslak

We present an efficient biomimetic model reaction for the complete P700 to ferredoxin-NADP+ reductase sequence occurring in natural Photosystem I. For the first time, a robust molecular photocatalyst has been successfully combined with the regioselective two-electron reduction of NAD+ to form NADH powered by red light [1].

Artificial photosynthetic production of NADH in aqueous buffer solutions was achieved with a water soluble tin chlorin sensitizer in a photochemical system with [Cp*Rh(bpy)(H2O)]2+ [2] as a co-catalyst. Coupling of this novel system to subsequent enzymatic dark reactions could also be demonstrated. The photophysical characterization of a water-soluble silicon phthalocyanine complex designed for applications in artificial photosynthesis and solar hydrogen production based on robust and earth-abundant materials will also be presented [3].


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[1] K. T. Oppelt, E. Wöß, M. Stiftinger, W. Schöfberger, W. Buchberger and G. Knör, submitted for publication. [2] E. Steckhan, Organometallics 1991, 10, 1568. [3] C. Uslan, K. T. Oppelt, L. M. Reith, B. Ş. Sesalan, and G. Knör, Chem. Commun. 2013. DOI:10.1039/C3CC44674C.

Keywords: Water-Soluble Chlorophyll Analogues For Red Light Driven Artificial Photosynthesis

Figure


Performance of 100 MWe Solar Thermal Parabolic Trough Power Plant at Cholistan desert in Pakistan

Irshad Ahmed 1, Muhammad Khurram Zafar 2

1Department of Mechatronics, Air University, Islamabad, Pakistan.2Department of Mathematics, Air University, Islamabad, Pakistan.

Pakistan is passing through a very serious electricity crisis. Electricity shortage has disrupted the industry, agriculture, commercial and residential sectors. The main reason for not producing enough electricity is its dependence on oil and gas. The oil is too expensive to afford and gas is not insufficient. Renewable energies such as solar, hydro and wind are available in abundance in the country. Pakistan is slowly moving to use renewable energies on small scale. However, large scale renewable power plants are yet to materialize. Even academic research papers related to the performance of large power plants are hard to find. This study is an effort to explore the thermal and economic performance of a 100 MWe solar thermal power plant in the Cholistan desert. For the study, a software called System Advisor Model (SAM) has been used to optimize the power plant with respect the size of the solar field and thermal storage for minimum levelized cost of energy (LOCE). Hourly data for a typical meteorological year is used for the simulation. The salient results are included in the attached table and diagram.


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Keywords: Energy crisis, Solar thermal power plant, Solar multiple, LCOE, Greenhouse gas avoidance

Annual electricity generated by 100 MW solar thermal power plant at Cholistan desert in Pakistan.

Levelized cost for electricity from 100 MW Solar thermal power plant at Cholistan desert in Pakistan


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Direct photosensitization of MoS3 by polymer-fullerene bulk heterojunction solar cells for hydrogen photo-production

Bruno Jousselme 1, Tiphaine Bourgeteau 1, Romain Brisse 1, Bernard Geffroy 1, Denis Tondelier 2, Christel Laberty Robert 3, Rémi De Bettignies 4, Vincent Artero 5,

Serge Palacin 1

1Laboratoire de Chimie des Surfaces et Interfaces, CEA/ IRAMIS/ SPCSI, 91191 Gif sur Yvette Cedex, France

2Laboratoire de Physique des Interfaces et Couches Minces, Ecole Polytechnique, CNRS, 91128 Palaiseau, France

3Laboratoire de Chimie de la Matière Condensée de Paris-UMR 7574, Université Paris 6, Collège de France, 11 place Marcelin Berthelot 75005, Paris, France

4INES, CEA-DRT/LITEN/DTS/LMPV, Institut National de l’Energie Solaire, Le Bourget du Lac, France5Laboratoire de Chimie et Biologie des Métaux, Université Grenoble 1, CNRS, CEA, 17 rue des Martyrs

38054, Grenoble Cedex 9, France

Providing energy for our planet in a sustainable way is one of the biggest challenges of this century. Among renewable sources of energy, sunlight is by far the most exploitable one, being inexpensive, non-polluting and abundant. Yet efficient harvesting, conversion and storage of solar energy remain a major challenge for smoothing out the temporal fluctuations of solar power and allowing on-demand use. Solar to chemical energy conversion, i.e. production of a fuel that carries a high energetic density stored within chemical bonds, is very promising. In particular, hydrogen produced through water splitting has emerged as a potential fuel for sustainable energy cycles, because its oxidation ‘back’ to water in a fuel-cell efficiently restitutes the stored energy, in the form of electricity and without waste. Up to now, solar hydrogen generation is efficient only in systems that use expensive photovoltaic cells to power electrolysis. Direct and low cost production of hydrogen from sunlight and water would be an ideal long-term solution, but is still a challenging issue.

Photocathodes have been developed with organic solar cell based on a P3HT:PCBM bulk hetero-junction directly coupled with molybdenum sulfide for the production of hydrogen. Both the light-harvesting system and the catalyst were deposited by low-cost solution-processed methods. The photocathodes display photocurrents higher than reference samples, without catalyst or without coupling with a solar cell. Gas chromatography analysis confirms the light-induced hydrogen evolution. The addition of titanium dioxide in the MoS3 film enhances electron transport within thick films and therefore the performance of the photocathode.

Keywords: Organic solar cell, MoS3 catalyst, Hydrogen evolution.


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Energy End Use Efficiency and 100% Renewable Energy means Equality, Freedom, Peace, Democracy and Local Employment

Tanay Sıdkı UyarMarmara University – Turkey

Sun provides the energy needed for life on earth. Heat and light provided by sun, kinetic energy of the moving air, chemical energy stored in biomass, potential energy of water molecules and huge geothermal resources are available on earth free of charge providing a living space for whoever needs it.without requesting any contribution from human beings.

The only request or suggestion from nature to humanity is to live in harmony with nature. It is a suggestion from nature for the benefit of humanbeings, it is a request from nature since humanbeings are not in a position to do a favor for nature. If they do not live in harmony with nature, nature takes it over and gets rid of the humanbeings.

Beginning with 1850s due to huge energy needs of Industrial Revolution and the lack of the renewable energy technologies humanity started to use fossil fuels without considering their externalities causing local and global disasters. Between 1973 and 1978, we face efforts to market waste heat from nuclear weapon material production facilities to solve the energy problems of the world After 1978 nuclear waste heat and after 1992 fossil fuel combustion considered to be as a problem more than a solution mainly in industrialised countries.

For any technology to be considered and implemented as a solution we need to have enough resource available (coal, uranium, wind or solar resource etc.), secondly we need to have the related conversion technology commercially available which will convert the resource to process heat and electricity which are the main types of energy used globally. The third criteria is to have the decision makers supporting the solution rather than problems.

Renewable energy resources were available before,are now available and will be available as long as we have sun. The renewable energy technologies are commercially available today and improving further as the number of the countries with decision makers on the solution side increases. Many countries are now working on the solution and trying to make a transition from fossil and nuclear age to solar age.

Todays agenda is how fast we can realize this transition? What are the barriers and how to overcome or handle this barriers? How quickly we can move in the direction of 100 % renewable energy and achieve our targets.

One critical approach is to target the solution and act accordingly from the beginning. This requires a first step of defining the problem correctly and finding solutions which can be implemented. There is no progress in the solution if you do not stop investing to create more problems. The problem was fossil fuel combustion and nuclear waste heat utilisation in our atmosphere for energy production and consumption. The solution today is energy end use efficiency and 100 % renewable energy.

In this contribution, the global efforts for the solution will be presented together with the conclusions of the IRENEC 2013 conference realized two months ago in Istanbul.

Renewable energy in cooperation with greenhouse gases acting as a blanket of our global prison is responsible for life on earth and ready to contribute further to supply 100 % of the energy needs of the human activities.

Renewable energy utilisation means equality since every plant, animal or human being can benefit


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equally from renewable energy resources; means freedom since is available next to the user without any central authority interference; means peace since,when compared with other energy resources, user is not required to be a part of the energy wars.

Keywords: Energy End Use Efficiency and 100% Renewable Energy means Equality, Freedom, Peace, Democracy and Local Employment

ORAL PRESENTATIONS

MONDAY19TH OF AUGUST

Monday, 19th of August

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Molecular Photovoltaics and Mesoscopic Solar Cells

Michael GrätzelEcole Polytechnique Fédérale de Lausanne (EPFL) Lausanne 1015 Switzerland

Learning from the concepts used by green plants photosynthesis, we have developed nanostructured systems affording efficient solar light harvesting and conversion to electricity and fuels [1]. Solar cells using dyes or semiconducting pigment particles as light harvesters supported by mesoscopic oxide scaffolds have emerged as credible contenders to conventional p-n junction photovoltaics. Separating light absorption from charge carrier transport, dye sensitized mesoscopic solar cells (DSSCs) were the first to employ a three-dimensional nanocrystalline junction for solar electricity production. A molecularly engineered donor-acceptor porphyrine dye w used in conjunction with a Co(II/III) complex based redox electrolyte has reached a solar to electric power conversion efficiency (PCE) of over 12 percent [2] under standard air mass 1.5 (AM1.5) reporting conditions (25°C, 1000 Watt/m2 solar intensity). The PCE of the same system attains 26% under ambient light and indoor conditions. These features along with excellent long-term stability have fostered first commercial applications. The industrial mass production of DSC’s focuses presently on light weight flexible cell embodiments made by a roll to roll process and the fabrication of see-through electricity producing glass panels for building integrated PV application. The production capacity attains attains currently the multi MW/year scale strong growth in sales is expected for the coming years. Recently another breakthrough was witnesses with the advent of hybrid inorganic/organic mesoscopic solar cells using perovskites as light harvesters [3]. Solid-state mesoscopic photovoltatics based on CH3NH3PbI3 pigments supported by a nancorystalline TiO2 scaffold and a solid state organic hole conductors presently attain a power conversion efficiency of 15 % and further substantial improvements in performance appear to be feasible. Finally we shall present our latest research pogress in the area of on the generation of chemical fuelsuse of mesoscopic semiconducting oxides of p-type Cu2O and n-type α-Fe2O3 (hematite) a acting as photo-anode and photo-cathode for solar fuel splitting of water into hydrogen and oxygen and the reduction of CO2 by visible light will also be presented.

References:

1. M. Grätzel Nature. 414 (2001),p 338.

2. A.Yella, H.-W. Lee, H. N. Tsao,1 C. Yi, A.Kumar Chandiran, Md.K. Nazeeruddin, E. W-G Diau,C.-Y Yeh, S. M. Zakeeruddin and M. Grätzel Science 334 (2011) 629.3. J. Burschka, N. Pellet, S.-J. Moon, R. Humphry-Baker, P. Gao, M. K. Nazeeruddin,and M. Grätzel Nature 499 (2013) DOI 10.1038/nature12340.4. J.Brillet1, J.-H. Yum1, M. Cornuz, T. Hisatomi, R. Solarska2, J.Augustynski2, M. Grätzel and K. Sivula. Nature Photonics 6 (2012) 824.5. S. C.Warren, K.Voïtchovsky, H. Dotan, C. M. Leroy, M.Cornuz F.Stellacci, C. Hébert, A. Rothschild and M. Grätzel, Nature Materials 2013. DOI: 10.1038/nmat3684.

Keywords: Molecular Photovoltaics and Mesoscopic Solar Cells


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Converting exhaust carbon into working carbon: from a linear to a circular C-economy

Michele ArestaCIRCC, via Celso Ulpiani 27, Bari 70126, Italy

Anthropogenic carbon dioxide is accumulating into the atmosphere because the natural C-cycle is not able to convert it. High levels of atmospheric CO2 are believed to be responsible of climate changes, being CO2 a greenhouse gas. Among technologies that may control the level of CO2, the capture from concentrated, continuous point sources is under consideration since time. Captured CO2 can either be disposed in natural fields (with further economic and energy costs, up to 60% of the produced energy) or utilized. Low-energy processes have been possible so far (production of chemicals in which the entire CO2 molecule is incorporated) converting a low fraction of the emitted CO2. In a changing paradigm of utilization of energy sources in which perennial sources of primary energy, such as solar energy, wind or even geothermal, are used on large scale at affordable costs, the conversion of CO2 into fuels is targetable that will allow the utilization of larger volumes of CO2. Particular attention is drawing the solar powdered conversion of CO2 that may result in a synthetic photosynthesis that may support carbon-cycling, moving from a linear- to a cyclic-economy, that may eventually contribute to control the CO2 accumulation into the atmosphere and reduce the utilization of natural resources of fossil-carbon. Synthetic photosynthesis will convert CO2 and water into energy rich carbon compounds and oxygen, mimicking what happens in Nature, not repeating the natural process that occurs in leafs. The man-made device that will support such C-cycling is constituted of several parts such as: systems for photons capture, photo-sensitizers for energy transfer, charge separation that generates positive centers where water can be oxidized and electrons that will be used in the reduction of CO2.

Several systems are known that may repeat such sequence, but still they are not ready for industrial exploitation. Key issues that need to be developed in order to have an efficient and durable device for C-cycling are the discovery of more efficient antennae for solar energy capture, the development of metal systems that may capture two-photons and use them for CO2 two-electron-reduction, the construction of efficient and durable centres for water oxidation to oxygen, the identification of selective centres for CO2 reduction to single chemicals. Both homogeneous and heterogeneous systems are known that are able to support a manmade-photosynthesis. In case solid semiconductors are used a key point is the stabilization of charge separation using junctions. that may prevent “electron-hole” recombination.

Keywords: Converting exhaust carbon into working carbon: from a linear to a circular C-economy


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Invited Lecture / 10:30-10:50 / Hall 1 Photovoltaic Materials and Devices III

Molecular Solar Cells and Essential Molecular Orbital Interactions for Unidirectional Electron Transfer and Transport

Shozo YanagidaEmeritus Professor, Osaka University, Suita, Osaka, Japan

Nobel laureates, W. Kohn, R. Hoffmann, and K. Fukui, teach us importance of the frontier molecular orbital picture, i.e., molecular interactions and chemical reactions can be analyzed from the starting point of the electron energy levels of the interacting fragments or molecules. In addition, recent DFT-based personal computer calculations enable our experimental scientists to visualize and understand the underlying molecular orbital (MO) interactions in molecular solar cells, i.e., DSC and OPV.

We recently succeeded in rationalizing the efficient and effective electron flow by DFT-based simulation of Z907-sensitized solar cells in which phenyl-capped aniline tetramer (EPAT) is introduced as a substitute of semiconducting iodine/iodide electrolyte solution. The Z907/EPAT solar cell gives a notable open-circuit voltage and short circuit photocurrent density but the case was not true for N719/EPAT solar cells. DFT-based molecular modeling give energy relationships of the frontier MO of EPAT and Z907 (Figure a). The DFT-simulated equilibrium geometry for the association of Z907 with EPAT has the energy structure of electron density (Figure b), and the electrostatic potential map accompanying the non-covalent bond distances (Figure c). The non-covalent bond distance between the sulfur of SCN and the hydrogen of N-H of EPAT, and the hydrogen-π-stacking distance between Z907 and EPAT suggest that molecular orbital interactions, i.e., van der Waals interactions contributes to the efficient and effective one-way electron transfer at the Z907/EPAT interface(Chem. Commun., 2013, 49, 1416-1418. )

The DFT-based simulation was successfully extended to semiconducting iodine-iodide electrolyes. The underlying molecular orbital interactions will be discussed in the session.

Keywords: Frontier molecular orbitals, DFT, DSC, Z907, van der Waals


Organic Photovoltaics as a Scalable, Sustainable Solar Generation Technology

David S GinleyResearch Fellow/ Group Manager, Process Technology and Advanced Concepts NREL

Organic photovoltaics (OPV) in its many guises has transitioned from a 5% to a nearly 12% technology over the last 5 years with no sign of the leveling off. In addition lifetimes in the range of 15 to 25 years have been observed. This talk will use recent data from the organic photovoltaic field, our own work and economic models to show a perspective on the current state of the art and then talk about the potential of computational materials design for both organic and inorganic components to transform the technology.


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While efficiencies have now surpassed 10% it is clear that both the absorber and contact materials need to be further optimized. The very large possible number of organic materials and that the contacts will have to be tailored to the organic materials suggests the need for a new approach to optimizing materials and interfaces. To this end we have begun to approach each of these areas by coupling high-throughput theory and experiment to develop both new organic and inorganic materials. We will discuss two examples of this approach: one is a computational approach to the development of new donor-acceptor pairs. We have shown that predictions for absorption and Voc can be experimentally realized. We are also developing similar tools to allow for the computation of new contact materials and TCOs. We will highlight in this area development of selective contacts that improve efficiency and lifetime for OPV devices, specifically inorganic hole-transport layers (HTL) and the related electron-transport layers (ETL) for organic photovoltaics. Most of the studied materials belong to the general class of wide-bandgap p-type oxide semiconductors. Coupled to the “conventional TCO’s” the pairing of new materials by design for the HTL and ETL potentially be tailored to a particular bulk heterojunction to improve efficiency and stability tailored to a particular bulk heterojunction. How we can begin to design such materials and then realize them experimentally is the topic of the talk. Potential candidates suitable for HTL applications include SnO, NiO, MO3, Cu2O (and related CuAlO2, CuCrO2, SrCu2O4etc) and Co3O4 (and related ZnCo2O4, NiCo2O4, MgCo2O4 etc.). Materials have been optimized by high-throughput combinatorial approaches. The thin films were deposited by RF sputtering and pulsed laser deposition at ambient and elevated temperatures. Performance of the inorganic HTLs and that of the reference organic PEDOT:PSS HTL were compared by measuring the power conversion efficiencies and spectral responses of the P3HT/PCBM- and PCDTBT/PCBM-based OPV devices showing performance comparable to PEDOT:PSS. This work then shows that materials for solar energy conversion can be much more rapidly developed using a materials by design approach driven by theory and continuously iterated with experiment.

Keywords: Organic Photovoltaics as a Scalable, Sustainable Solar Generation Technology

Oral Presentation - 280 / 11:10-11:25 / Hall 1 Photovoltaic Materials and Devices III

Wide variety metal nanoparticle incorporation into polymer matrix for solar cell application

Vladimir AstachovDepartment of Mechanical, Materials and Manufacturing Engineering, University of Nottingham,

Nottingham, United Kingdom

Polymer solar cells have achieved considerable attention because of their favourable properties such as lightweight, flexibility and durability. The main problem is their low efficiency and high price compared to silicon based solar cells. The solution of this problem is the improvement of the active material in solar cell (both donor and acceptor). Improvement can be achieved if the solar cell absorbs as much as possible light. The active material can absorb light mainly because of few reasons. First reason is the surface morphology. And second reason is the internal nanomorphology of the active layer. In this work several metal nanoparticles were incorporated into hybrid material P3HT/PCBM[70] solar cell in order to improve the absorbance of the active layer. The nanomorphology of the active layer depending on mixture of the solvents and nanoparticles was investigated using atomic force microscopy (AFM), scanning electron microscopy (SEM). Optical techniques such as Fourier-transformed-infrared spectroscopy (FTIR) and absorbance UV-vis spectrometry were used in order to draw conclusions on the chemical bonding and suitability as absorbing layer for solar cells, respectively.

Keywords: nanomorphology, polymer solar cells, (SPR), nanoparticles.


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Oral Presentation - 288 / 11:25-11:40 / Hall 1 Photovoltaic Materials and Devices III

Charge transport in nanoporous materials for solar energy conversion

Steven J KoneznyEnergy Sciences Institute, Yale University, West Haven, CT, USA

The mechanism of charge transport in nanoporous materials plays an important role in many renewable energy strategies. Thin films of annealed nanoparticles have large active areas for solar light harvesting and photocatalysis, though this advantage comes at the expense of limited charge carrier mobilities and collection efficiencies. Although many important contributions have been made in this field, a better understanding of the structure-electronic property relationships is needed in order to design materials with optimal overall solar energy conversion efficiency.

I will present microscopy and temperature-dependent electrical measurements of annealed metal oxide (e.g., TiO2, SnO2, and Fe2O3) nanoparticle thin films that exhibit the characteristic behavior of fluctuation-induced tunneling conductivity (FITC), i.e., a smooth transition from thermally activated to temperature-independent conductivity with decreasing temperature. These data suggest that the FITC mechanism is applicable to most nanoporous metal oxides and appropriate for an even broader class of energy-related materials that share a similar microstructure.

A unique feature of FITC compared to the models previously proposed for nanoporous metal oxides is that electron transport is limited by the physical size and energy level alignment of the interparticle contact junctions, rather than by any homogeneous distribution of hopping or trapping sites throughout the film or by the electronic properties of the nanoparticle cores. This calls for a revised materials design strategy that incorporates optimization of the contact junctions using the FITC model as a guide.

Keywords: charge transport, fluctuation-induced tunneling conductivity, nanoporous materials, nanoporous metal oxides, solar energy conversion, photocatalysis


Recent progress in small-molecule organic solar cells

Karl LeoInstitut für Angewandte Photophysik, Technische Universität Dresden, 01062 Dresden

Carbon-based organic semiconductors have many potential advantages like easy large-area preparation on flexible substrates, large variety of materials, and low cost. Although known for a century, organics have achieved little impact until OLED displays entered the market about a decade ago, demonstrating that organic semiconductors are ready for significant commercial markets. So far, OLED displays are based almost exclusively on small-molecule organic semiconductors due to their advantages in processability and deposition as multilayer devices.

In this talk, I will present an overview over the key features of small-molecule organic solar cells and recent developments in the field. One central research area is the design of the bulk heterojunction


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active layer, requiring a nanoscale phase separation and optimized morphology to achieve efficient operation. This is particularly challenging for small-molecule devices. A key challenge of the field is to find design rules which relate the molecular structure of absorber materials to layer morphology and cell properties. The difficulty is that small changes of the molecular structure, leaving the electronic properties of the individual molecule nearly unchanged, can lead to large changes in the crystal packing and molecular orientation, causing significant differences in the electronic properties in the active layer. Furthermore, I will discuss highly efficient tandem structures with optimized electrical and optical properties. Very efficient recombination contacts can be realized by n- and p-type doped transport layers. Structures based on these approaches have reached efficiencies of 12% and have the potential to reach approximately 20%. Furthermore, these high-efficiency cells also show encouraging lifetimes.

Keywords: Recent progress in small-molecule organic solar cells

Invited Lecture / 10:30-10:50 / Hall 2 General, Technology and Systems

Printed Solar Cells on Paper – A Paradigm Shift

Arved C HueblerInstitute for Print and Media Technology, Chemnitz University of Technology, Chemnitz, Germany

In the recent years printed electronics became an interesting field of technology. New materials like functional polymers and nano composites offer the opportunity to process them as a liquid, e.g. as printing inks. Two years ago, our group introduced a new approach printing solar cells called 3PV, printed paper photo voltaics. With traditional mass printing techniques, without clean room and vacuum processing, we are able to produce in lab scale solar cells on ordinary paper.

This presentation will compare traditional electronics and printed electronics to emphasize the different capabilities. It offers a short overview of the basics of printed electronics in general and the specifics of printed solar cells, focusing on materials, process and functionality.The technical restrictions and challenges and the development opportunities are discussed.

The significant differences of solar cells on paper compared to traditional silicon devices lead to a new framework for possible applications, too. In a second section some new ideas for the use of the 3PV technology are presented.

Keywords: solar cells, printing, paper, printed electronics


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Materials design for organic solar cells: the potential for piezoelectric enhancement of photovoltaic efficiency

Safa Shoaee 1, Joe Brisco 2, Steve Dunn 1, James Durrant 2

1Centre for Plastic Electronics, Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom

2Centre for Materials Research, School of Engineering and Materials, Queen Mary University of London, E1 4NS, UK

My talk will be focused on materials design for organic solar cells. I will start by summarising some of our recent observations concerning key design consideration for the efficiency and stability of polymer / fullerene solar cells, including in particular materials design for efficient charge separation, the impact of film morphology upon this charge separation, and the importance of photo-induced PCBM oligomerisation in stabilising this morphology. I will then go on to discuss in more detail the potential of acoustic vibrations to enhance significantly photocurrent generation and solar to electric power conversion efficiency of a hybrid organic-inorganic P3HT: ZnO nanorod photovoltaic cell. The application of modest external vibration (10 kHz at 75dB, equivalent to a loud office environment) is shown to cause a 45% increase in device efficiency, correlated with a 3-fold increase in charge carrier lifetime. By identifying reduced recombination as the origin of the performance enhancement, and with comparison to control systems, we propose a mechanism based on the piezoelectric properties of ZnO nanorods as the source of the enhancement, with the oscillating piezoelectric dipoles generated by acoustic noise aiding the spatial separation of electrons and holes. This study demonstrates the potential for piezoelectric effects to enhance the solar to electric power conversion, and a novel approach to enhancing the photovoltaic energy conversion applicable to environments with significant levels of ambient vibrations by

Keywords: Materials design for organic solar cells: the potential for piezoelectric enhancement of photovoltaic efficiency

Oral Presentation - 350 / 11:10-11:25 / Hall 2 General, Technology and Systems

HCPV grid-connected power plant for training and research at the University

Abdelfettah Barhdadi 1, My Abdelmjid Sebbar 1, Hassane Jaziri 2, Graziano Beghelli 3, Gianni Borelli 3, Daniele Verdilio 3, Maurizio Carpanelli 3

1Semiconductors Physics and Solar Energy Research Team (PSES), Ecole Normale Supérieure, University Mohammed V Agdal, PO Box: 5118-Takaddoum, Rabat, Morocco

2Biology Department, Ecole Normale Supérieure, University Mohammed V Agdal, PO Box: 5118-Takaddoum, Rabat, Morocco

3BECAR s.r.l, Beghelli Group Viale della Pace, 1 - 40050 Monteveglio, Bologna, Italy

The High Concentration Photovoltaic Technology (HCPV) is a promising alternative option to both PV-flat solutions and Concentrated Solar Power (CSP ) based on heat generation technology, especially for application in desert areas where the high temperatures decrease the flat PV performance on one


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hand and the lack of water prevents the easy deployment of CSP, on the other hand.

As today the low cost, reliability and efficiency of HCPV modules has been demonstrated, while a weak chain is still the solar tracker, a component which is needed to keep the photovoltaic modules constantly aligned with the sun rays. The precision solar trackers, high cost reduction and reliability increase are the challenges to achieve for the HCPV technology definitive take-off.

In this perspective, a new HCPV power plan system from Beghelli Group Industry has been recently installed at home University with the aim of setting up a small RDI platform of CPV technology. This will allow researchers and PhD/Master’s degree students to develop specialized training sessions and to perform proper research activities on novel HCPV systems. The focus is the design, the development, the realization and the testing of complete reliable and cost-effective high concentration Photovoltaic tracker to boost the introduction of HCPV systems in the market.

The presentation of HCPV system, its installation and its operating are the topics that will be explained in this scientific communication. Steps toward the implementation of the first African high concentration photovoltaic platform for training, research and innovation will also be presented and commented.

Keywords: Solar Energy, High Concentration Photovoltaic Technology and Systems, RDI platform

Oral Presentation - 57 / 11:25-11:40 / Hall 2 General, Technology and Systems

Techno-economic investigation of an boiler – solar water heater energy saving system in Al-alBayt University

Mohammad Hamdan Al SmairanEnergy Research Center, Al-alBayt University, Mafraq, Jordan

Jordan is relatively poor in conventional energy resources and must rely on neighboring Arab oil producing countries. One of the most important energy sources in our economy is still oil, which is not renewable considering our lifetime. Jordan is an energy importing country, it imports almost 95% - 97% of its energy needs in the form of oil and petroleum products.

Fuel consumption for heating in Al-alBayt University during the last years was considered high and the energy bill is very expensive for the University, especially with the increase in the oil prices. Meanwhile, Al-alBayt University has 4600 flat plat solar collector.

Integration of boiler with solar energy systems for domestic hot water as well as for building space heating can save energy and therefore, can reduce the energy cost for domestic uses. Due to the increase in the fuel cost, the idea of integration boiler-solar energy saving system shows that a significant market segment is willing to invest in this system.

During our investigation, 84 flat plat solar collector was integrated with the boiler and the initial draft and design of a prototype for the boiler – solar collector integration system has been carried out.

The present investigation main aim is to develop a new energy saving system that integrates solar energy and boiler systems for heating purposes to study the possibility of exploitation of solar collectors in the Al-alBayt University for the purpose of domestic hot water as well as for building space heating.

Keywords: Badia, Jordan, solar collector, boiler, saving system, integration system


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Devoloping Weavable Dye Sensitized Solar Cells Based on Carbon Nanotube Yarns

Josef Velten 1, Özer Göktepe 2, Zharkynay Kuanyshbekova 3, Fatma Göktepe 2, Anvar Zakhidov 1

1The Alan G. MacDiarmid NanoTech Institute, University of Texas at Dallas 800 W. Campbell rd. Richardson, Texas 75083, United States of America

2Namik Kemal University, Çorlu Engineering Faculty, Textile Engineering Department, Çorlu- Tekirdağ/ Turkey

3Kanysh I. Satbaev Kazakh National Technical University, Almaty 050013, Kazakhstan

In this study, we aimed at to develop weavable dye sensitized solar cells (DSSC) by using carbon nanotube (CNT) yarns. For this purpose, fermat CNT yarns were spun from multi walled carbon nanotube (MWCNT) forests firstly. Then these yarns were heat set in a vacuumed furnace and coated with mesoporous TiO2 and this coating process repeated after eight individual yarns were plied together. Finally the electrode of the solar cell was obtained by heat setting these plied and re-coated yarns in the same furnace.. On the other hand archimedian yarns of MWNTs coated with a thin layer of Platinum prepared as a counter electrode to complete the architecture used in this DSSC. This weavable DSSCs enabled us to achieve a power conversion efficiency over 3%.

Keywords: CNT yarns, Dye Sensitized Solar Cells, Photovoltaics

Invited Lecture / 13:00-13:20 / Hall 1 Solar Energy Materials and Devices

Challenges In Printing Organic Solar Cells

Andrew Bruce Holmes, Michael Brown, David J. Jones, R. John Kumar, Balaji Purushothaman, Helga Seyler, Jegadesan Subbiah, Wallace W. H. Wong, Zehun Xiao

School of Chemistry, Bio21 Institute, University of Melbourne, Victoria 3010, Australia

In recent years there has been much interest in the use of blends of organic polymeric and small molecule materials with fullerene derivatives to form bulk heterojunction solar cells. For laboratory-based devices attention has been focused on preparing light harvesting materials consisting of donor-acceptor pi-conjugated molecules or polymers that have the appropriate HOMO-LUMO energy gap that is suitable for absorbing light in the range of the sun’s emission maximum. Other factors that contribute to a high energy conversion efficiency include balanced charge mobility in the p-type and n-type components, morphology control and high open circuit voltage, Voc, short circuit current, Jsc, and fill factor, FF. In this presentation the work of the Victorian Organic Solar Cell Consortium (VICOSC) will be summarised. The talk will illustrate the integrated nature off the project with contributions and skill sets ranging from materials design and synthesis to device physics and printing as well as encapsulation. This combination has produced efficient in-house materials as well as fully printed solar cell modules by a reel-to-reel deposition process

Keywords: Challenges In Printing Organic Solar Cells


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Oral Presentation - 142 / 13:20-13:35 / Hall 1 Solar Energy Materials and Devices

Identifying the surfaces of a running electrochemical cell

Sarp Kaya 1, Hernan Sanchez Casalongue 2, May Ling Ng 2, Hirohito Ogasawara 3, Jesse Benck 4, Thomas Jaramillo 4, Anders Nilsson 2

1Department of Chemistry, Koc University, Istanbul, Turkey2SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory, Menlo Park, USA3Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, USA

4Department of Chemical Engineering, Stanford University, USA

Photo-electrochemical water splitting provides viable methods for generating hydrogen and oxygen using the energy from sunlight. An over-potential is commonly required in order to drive hydrogen and oxygen evolution reactions on the photocathode and photoanode materials, and it is directly related to the stability of the surface species in operational conditions. In addition to the light absorption efficiency, the design of an efficient and feasible photo-electrochemical cell is possible with the control of chemical activity, it is thus crucial to know about the surface intermediates that are controlling the potential dependent hydrogen and oxygen formations reactions. Ambient pressure x-ray photoelectron spectroscopy is a powerful technique that enables us to study water splitting reactions in running cell conditions; that also gives information about surface composition and also electronic structure of the anode/cathode materials under investigation. We demonstrate that MoS3/MoS2 amorphous/crystalline nanoparticles active for hydrogen evolution reaction (alternative to Pt) undergo a severe structural modification in extensive hydrogen evolution conditions without significant drop in activity determined by cyclic voltammograms. Mo and S XPS spectral features obtained in 5-10 Torr water vapor by applying potential indicate MoS3 to MoS2 conversion. The investigations on the complementary oxygen evolution reaction on IrO2 nanoparticles indicate that the surface is terminated by hydrated OH species at low potentials, whereas it is more like OH terminated at high potentials. The overall turnover and over-potentials can be improved by the rational design of the surfaces; the studies in running cell conditions thus remain critical.

Keywords: Ambient pressure XPS, hydrogen evolution, oxygen evolution, MoS2, IrO2

Electrochemical cell


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Evaluation of the Thermo-oxidative Stability of Polyethylene Liner Materials for Hot Water Heat Storages

Klemens Grabmayer 1, Gernot M. Wallner 1, Susanne Beißmann 2, Ulrike Braun 3, David Nitsche 4, Reinhold W. Lang 1

1Institute of Polymeric Materials and Testing (IPMT), Johannes Kepler University, Altenberger Straße 69, 4040 Linz, Austria

2Institute of Analytical Chemistry (IAC), Johannes Kepler University, Altenberger Straße 69, 4040 Linz, Austria

3Bundesanstalt für Materialprüfung, Unter den Eichen 87, 12205 Berlin, Germany4AGRU Kunststofftechnik, Ing.-Pesendorfer-Straße 31, 4540 Bad Hall, Austria

A specific focus of the cooperative research projects SolPol-1/2 is on the development of polymeric liner materials for hot water heat storages. Liner materials are primarily based on polyolefins. A prime requirement for hot water storages is the enhancement of thermo-oxidative and hydrolytic stability fulfilling lifetimes of up to 25 years at continuous operating temperatures of about 70°C. Within this work two polyethylene based grades were investigated using accelerated aging test methods.

Conventional tensile test specimens (ISO 527; specimen type 5A) as well as micro-sized specimens with a thickness of 100 µm were prepared from 2 mm thick compression molded sheets. Accelerated aging tests were carried out in air and water at atmospheric pressure at temperatures up to 115°C as well as in water at enhanced oxygen pressure of 50 bar at 95°C. The specimens were removed at constant intervals and characterized by differential thermal analysis (aging indicator: oxidation induction temperature OITtemperature) and tensile testing (aging indicator: strain at break eB). Moreover, the consumption of stabilizer was investigated by wet-chemical analysis (HPLC, UV and MS detection).

Preliminary results show a consistent trend in the decrease in OITtemperature and stabilizer concentration. At atmospheric pressure, embrittlement of the materials was reached for the micro-sized specimens at 115°C with embrittlement times of 77 days and 140 days. Aging in water at 50 bar partial pressure of oxygen revealed a faster degradation of the materials within 40 days. Based on the overall results a clear and consistent ranking of the investigated materials was possible.

Keywords: Liner materials, Hot water Heat Storage, Polyolefin, Thermo-oxidative Stability, Accelerated Aging


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Charge transport properties of the highly efficient organic photovoltaic material PTB7

Bernd Ebenhoch 1, Stuart A. J. Thomson 1, Kristijonas Genevicius 2, Gytis Juška 2, Ifor D. W. Samuel 1

1Organic Semiconductor Centre, SUPA, School of Physics & Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK

2Department of Solid State Electronics, Vilnius University, Saulėtekio 9 III k., 10222 Vilnius, Lithuania

Solution processed organic solar cells are attractive candidates for electricity generation, because of their potential for low-cost production with low embedded energy by simple printing-like processes. In recent years their efficiency increased dramatically due to the development of new materials. One of the most efficient material combinations is PTB7 (Poly[[4,8-bis[(2-ethylhexyl)oxy] benzo[1,2-b:4,5-b’] dithiophene-2,6-diyl][3-fluoro-2- (2ethylhexy)carbonyl] thieno[3,4-b]thiophenediyl]]) blended with [C70]PCBM ([6,6]phenyl C71 butyric acid methyl ester) to form a bulk heterojunction with a power conversion efficiency reaching up to 9.2 % [1].

We report a study of electron and hole mobility and recombination in PTB7:[C70]PCBM using two techniques: time of flight (TOF) and photo-generated charges extracted by linearly increasing voltage (photo-CELIV). The results were compared with measurements on the prototypical materials system P3HT:[C60]PCBM (Poly(3-hexythiophene):[6,6]phenyl C61 butyric acid methyl ester). We found higher charge carrier mobility in PTB7 devices and reduced recombination, and relate these observations to the high fill factor and external quantum efficiency of the PTB7 devices.

References:

[1] Z. He, C. Zhong, S. Su, M. Xu, H. Wu, Y. Cao, “Enhanced power-conversion efficiency in polymer solar cells using an inverted device structure”, NATURE PHOTONICS, VOL 6, 2012

Keywords: Organic Photovoltaic, PTB7:[C70]PCBM, P3HT:[C60]PCBM, mobility, recombination


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Invited Lecture / 14:10-14:30 / Hall 1 Solar Energy Materials and Devices

Phthalocyanines for molecular photovoltaics

Tomas Torres1Organic Chemistry Department, Autonoma University of Madrid

2IMDEA Nanoscience, Cantoblanco

Porphyrinoids are employed as components of photovoltaic and artificial photosynthetic devices [1]. However, synthetic porphyrin analogues such as phthalocyanines [2] have the advantage, as photon harvesters, of exhibiting very high extinction coefficients in a wavelength range that extends to around 700 nm, where the maximum of the solar photon flux occurs. Consequently, Pcs have emerged as excellent light harvesting antennas for incorporation into donor-acceptor systems, mainly in connection with carbon nanostructures as acceptor moieties. During this talk an overview of the results obtained by our group in Madrid will be given [3-5]. [1] Bessho, T.; Zakeeruddin, S.M.; Yeh, C.-Y.; Diau, E. W.-G.; Graetzel, M. Angew. Chem. Int. Ed. 2010, 49, 646-6649.[2] de la Torre, G.; Claessens, C.G.; Torres, T Chem. Commun. 2007, 2000-2015.[3] Martínez-Díaz, M. D.; de la Torre, G.; Torres, T. Chem. Commun. 2010, 46, 7090-7108. [4] Bottari, G.; de la Torre, G.; Guldi, D.M.; Torres, T. Chem. Rev. 2010, 110, 6768– 6816.[5] Ragoussi, M.E.; Cid, J.J.; Yum, J.H.; de la Torre, G.; Di Censo, D.; Graetzel, M.; Nazeeruddin, M.K.; Torres, T. Angew. Chem. Int. Ed. Eng. 2012, 51, 4375 –4378.

Keywords: Phthalocyanines for molecular photovoltaics

Invited Lecture / 13:00-13:20 / Hall 2 General Theory, Technology and Systems

How Solar Cells Work

Peter WuerfelDepartment of Physics, Karlsruhe Institute of Technology, Karlsruhe, Germany

Solar energy conversion proceeds in two steps. In a first step, chemical energy is produced from solar radiation by the generation of electron-hole pairs or excitons in semiconductors or molecules. The amount of their chemical energy depends on their steady state concentrations and is, in the end, limited by thermodynamics. In a second step, chemical energy of electron-hole pairs or excitons is converted to electrical energy. This step is not limited by thermodynamics. It requires the structure of a solar cell. Contrary to a widespread belief, there is no driving force in a solar cell which would drive electrons to one contact and holes to the other contact. Instead, the driving forces, gradients of the quasi-Fermi energies, drive electrons and holes towards both contacts. The necessary asymmetry in the currents is achieved by an asymmetric distribution of their conductivities. This is the reason, why a n-type region is required in front of the electron contact and a p-type region in front of the hole contact. However, a pn-junction is not ideal. It is true that there is a big difference between majority and minority carrier conductivities in the dark provided by the doping. This asymmetry would be sufficient, if it were not for the illumination by which the minority carrier concentrations are increased by many orders of magnitude. The increase of the minority carrier concentrations provides for the chemical energy to be converted into electrical energy, but at the same time it spoils the performance of a pn solar cell. Improvements of the structure are needed and will be discussed.

Keywords: chemical energy, electrical energy, driving forces, ideal structures


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Oral Presentation - 66 / 13:20-13:35 / Hall 2 General Theory, Technology and Systems

All We Need Is Light Photoprocesses In Chemical Education

Michael Walter TauschBergische Universität Wuppertal, Germany

Core principles of chemistry should be communicated in close combination with modern applications from science and technology as well as with everyday experiences of students. Photochemical and photophysical processes are par excellence suitable to fulfill this requirement. Therefore research in chemical education is challenged to explore and develop experiments, concepts and teaching materials which help to interpret and communicate photochemistry in a way that is for students both, exciting and understandable.

The lecture shows an experimental approach to a conceptual framework able to explain all basic phenomena involving light in a reasonable approximation for students in high schools, colleges and universities.

Literature

[1] M. W. Tausch, A. Banerji, U. Scherf: “Classroom Experiments and Teaching Materials on OLEDs with Semiconducting Polymers”, Education Quimica, 24 (1), 17 (2013)[2] M. W. Tausch, J. G. Ibanez, I. Fernandez-Gallardo, A. Robles-Leyzaola, C. Bohrmann-Linde, S. Krees, N. Meuter: “The Basis for Photocatalytic Writing”, Journal of Chemical Education 88, 116 (2011)[3] M. W. Tausch, C. Bohrmann: „Photogalvanic Cells for Classroom Investigations – A Contribution for the Ongoing Curriculum Modernization“, Journal of Chemical Education, 80 (12), 1471 (2003)

Keywords: Photochemical Reactions, Teaching Experiments, Basic Concept


Toward Clean and Sustainable Energy: Fuel Cells and Hydrogen’s Synergy

Larhrafi Malika, Zazi KhalidaCentre National de Recherche Scientifique et Technique (CNRST)

The issues surrounding climate change emissions of greenhouse gases, the depletion of limited fossil fuels, global policy calls for sustainable development and environmental protection have stimulated the creation of a critical mass of opinions and interventions aimed at accelerating the development and adoption of new technologies to reduce emissions. There is no doubt that fuel cells and hydrogen, the cleanest of fuel, are part of these technologies. Hydrogen whose primary trump is the perspective of being able to dispose of them properly, embodies the dreams of inexhaustible continue, clean and sustainable energy sources through the use of intermittent renewable energy sources (wind, sun, waves,) to extract hydrogen by electrolysis of one of the most plentiful reserves on the planet ‘water’. But the exhaustive exploitation of these energy sources in the futur, requires the development of sustainable and profitable methods of production, storage and transportation of hydrogen. The use of renewable energies in hydrogen energy technologies and fuel cells, where they could be stored, may remove obstacles of immediacy and intermitency of these energies and provide a profitable market to these precious resources.

Keywords: hydrogen, fuel cell, sustainable energy


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Light harvesting from first principles in the time-domain

Carlo Andrea Rozzi 1, Sarah Maria Falke 2, Nicola Spallanzani 3, Angel Rubio 4, Elisa Molinari 1, Daniele Brida 5, Margherita Maiuri 5, Giulio Cerullo 5,

Heiko Schramm 6, Jens Christoffers 6, Christoph Lienau 2

1Istituto Nanoscienze – CNR, Centro S3, Modena, Italy2Institut für Physik and Center of Interface Science, Carl von Ossietzky Universität, Oldenburg, Germany

3Dipartimento di Fisica, Università di Modena e Reggio Emilia, Modena, Italy4Dpto. Física de Materiales, Universidad del País Vasco, San Sebastián, Spain

5IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Milano, Italy6Institut für Reine und Angewandte Chemie and Center of Interface Science, Carl von Ossietzky

Universität, Oldenburg, Germany

Nature has developed sophisticated and highly efficient molecular architectures to convert sunlight into chemical energy. It is known that the primary steps, specifically both energy and charge transfer, occur on extremely fast time scales. These processes have traditionally been interpreted in terms of the incoherent kinetics of optical excitations and of charge hopping, but recently signatures of quantum coherence were observed in energy transfer in photosynthetic bacteria and algae [1,2]. We have studied the early steps of photoinduced charge separation in an an organic donor-bridge-acceptor supramolecular assembly [3] by combining Time-dependent Density Functional Theory simulations of the quantum dynamics and high time resolution femtosecond spectroscopy. We discuss the role of the electron-nuclei coupling and of the linking group in the photoinduced charge separation process. Our results provide evidence that the driving mechanism of the charge separation process is a quantum correlated wavelike motion of electrons and nuclei on a timescale of few tens of femtoseconds, thus establishing the role of quantum coherence in artificial light harvesting [4].

[1] G. S. Engel et al. Nature 446, 782-786 (2007)[2] E. Collini et al. Nature 463, 644-647 (2010)[3] G. Kodis et al. J. Phys. Org. Chem. 17, 724-734 (2004)[4] C. A. Rozzi et al., Nat. Comm. 4, 1602 (2013)

Keywords: light-harvesting, time-dependent density functional theory, pump probe spectroscopy

Pump probe

Coherent charge transfer dynamics in a carotene-porphyrin-fullerene triad. (a) Experimental differential transmission map as a function of time delay and probe wavelength recorded following impulsive excitation of the triad at around 550 nm. The blue and red lines highlight the time evolution of the center wavelengths of the porphyrin and charge transfer bands, respectively. These center wavelengths have been extracted from the experimental data by fitting the spectra of both bands to Gaussian lineshape functions. (b,c) Temporal evolution of the amplitude (b) and spectral position (c) of the charge transfer band. The dashed lines are guides to the eye, emphasizing coherent oscillations of both amplitude and center wavelength of the charge transfer resonance.


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Invited Lecture / 14:10-14:30 / Hall 2 General Theory, Technology and Systems

Multiscale Simulation of Molecular Photovoltaic Materials and Devices

Jenny Nelson, Jarvist M. Frost, Florian Steiner, Anne Guilbert, Sheridan Few, Christopher Emmott, Roderick Mackenzie, Thomas Kirchartz

Centre for Plastic Electronics and Department of Physics, Imperial College London, London SW7 2AZ, U. K.

Emerging solar photovoltaic technologies, such as those based on printable molecular or inorganic thin films, are attractive because of their potential to reduce the cost and the carbon intensity of solar electricity. However it is challenging to predict the contribution that such new PV technologies can make to power generation because there is as yet no reliable means to predict device output from knowledge of the materials, and little operational experience.

In the case of molecular based solar cells, device simulation is challenging because the optoelectronic properties of the molecular semiconductor materials and devices are strongly influenced by the chemical structure and microstructure of the materials. In order to relate device performance to molecular structure, two factors must be addressed. The first is to predict relevant optoelectronic parameters (charge mobility, lifetime, generation efficiency and density of states) from chemical structure and molecular packing. The second is to explain OPV device performance in terms of those parameters. The challenge is complicated by the intrinsic disorder and heterogeneity of molecular and nanostructured semiconductors.

We have developed multi-scale methods incorporating electronic structure calculation, molecular dynamics, quantum chemical calculation, and Monte Carlo simulation in order to explain the electronic properties of a variety of OPV materials. We use these methods to rationalise the influence of chemical structure on molecular packing, to explain charge transport properties of a range of materials and to access the energetic disorder that results from variations in conformation and chemical structure. We show how one-dimensional continuum device models can be adapted to incorporate energetic disorder and to understand the processes of charge recombination and current generation in OPV devices.

Finally, we use system scale modelling in order to assess the potential of organic PV technology to contribute to power generation and emissions mitigation in the future.

Keywords: Multiscale Simulation of Molecular Photovoltaic Materials and Devices


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Let It Shine: The 6000-Year Story of Solar Energy

John PerlinThe Department of Physics at UC Santa Barbara

Let it Shine presents the step-by-step development of solar architecture and technology and pertinent energy policies. By providing the background for today’s vibrant solar industry, a deeper understanding emerges of how solar energy applications have evolved and performed and their promise for today’s world. The book is not merely a technological treatise though. It highlights the context in which these developments have occurred and the people who have made the solar revolution possible, revealing a whole new group of unknown technological pioneers, as well as people famous for other accomplishments never before known for their work as the solar advocates and technologists they were. Who would think Socrates as a solar promoter? Yet in a work by his admirer Xenophon, Socrates presents the basic plans for designing a solar house. Vitruvius, a Roman famous to this day as the architect of architects, transmitted the wisdom of the Greeks on building with the sun. Did you know that the first aspiring solar entrepreneur was Leonardo da Vinci? Einstein’s famous treatise on Light Quanta, which won him the Nobel Prize, definitely qualifies the great scientist to be regarded as the father of modern photovoltaics. Then there are the forgotten ones like Gustav Vorherr, who opened up the first school of solar architecture during the 1820s in Munich and his mentor, Dr. Bernhard Christoph Faust, the first person to write a complete book on a solar topic. Thousands of newly trained solar architects trained in the work of Faust fanned out to build solar homes throughout Europe. Sympathetic despots of Bavaria and Prussia required their subjects to build following the teachings of these men, resulting in many solar structures going up in Europe during the first half of the nineteenth century. The climax of their work was the transformation of an urban area in Switzerland becoming the first modern Sun City. And who has heard of Williams Grylls Adams and Richard Evans Day, discoverers in 1876 of photovoltaics, or Charles Fritts, who put up the first roof-top solar array on a New York building in the 1880s?

Keywords: Let It Shine: The 6000-Year Story of Solar Energy


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SELEKTIF Technology Co. Inc. is an innovative SME supported by Small and Medium Companies Association and established in the Istanbul Technical University Campus in Techno City since 2009. The goal of the company is to conduct and promote research and development in the field of solar thermal energy by transferring the results into industrial application.

SELEKTIF has a specific roll to roll nano process technology for surface coating of substrates to enable selective solar thermal properties. It filled a PCT patent which is published by WIPO in May 2012.

Solartechnik Prufung Forschung Institute fur Solartechnik (SPF), Rapperswill, is qualified the Selektif product with solar absorbance coefficient between %93-95 and emittance coefficient between %3-5 with standard deviation less than 0,01. The tested coating is accredited to withstand the thermal loads of a flat plate collector more than 25 years.

Main Office: Arı Teknokent İstanbul Teknik Universitesi Ayazaga Kampusu

Otomasyon Bınası, No:4 34469 Maslak-İstanbul

Branch: Turgut Reis Mah. Karatay sok. No:3A Kat 2 34930

Sultanbeyli-İstanbulTel: +90 216 4988751 Fax: +90 216

4988751e-mail: [email protected] Web: www.selektif.com.tr

POSTERPRESENTATIONS

Poster Presentations

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Abstract:0006

Bilayer Heterojunction Solar Cells Using LC

Nimet Yilmaz Canli 1, Serap Günes 1, Belkız Bilgin Eran 2

1Yildiz Technical University, Department of Physics2Yildiz Technical University, Department of Chemistry

Photovoltaic devices based on organic materials have attracted attention in the last years because of their advantageous properties, such as low cost, light weight, possibility of producing large area and flexible devices. Nowadays several research groups have reported power conversion efficiencies around 10% motivating even more the research in the field. Poly(3-hexylthiophene) (P3HT) has attracted a lot of attention as a donor material, as it has one of the highest charge carrier mobility among the conjugated polymers. The use of a C60 molecule sublimed onto the polymer in a heterojunction or mixed in the polymer film increased drastically the efficiency of the photovoltaic devices.

Schmidt-Mende and co-workers reported a novel methodology of controlling nanostructured p-n junction in OPVs using discotic liquid crystal molecules and they have reported that using liquid crystal molecules, charge transport in OPVs could be enhanced. Furthermore, effects of a chemical additive into polymer/fullerene bulk-heterojunctions have been investigated by several groups. Using chemical additives results in significant improvement of the efficiency of organic solar cells and it is rather simple method as compared to other treatments.

We have investigated the effect of chiral (S)-5-octyloxy-2-[{4-(2-methylbuthoxy)-phenylimino}-methyl]-phenol Liquid Crystalline Compound (Lc) addition into P3HT:C60 solar cells. Based on current-voltage characteristics, the efficiency of devices with liquid crystal is found to be higher than that of devices from pristine blends of P3HT:C60. Significant improvements have been achieved by using this liquid crystal additive.

Keywords: Polymer solar cells, liquid crystal, organic solar cells, conjugated polymers

Abstract:0008

On the stability of the electrical and photoelectrical properties of P3HT:PCBM blend thin films

Mihaela GirtanPhotonics Laboratory, Angers University, France

For the first time the temperature dependencies of the electrical conductivity in dark and under different illuminations were studied for the P3HT and P3HT:PCBM blend films. These dependencies show reversible processes and high sensitivity of the P3HT and P3HT:PCBM to light. For a irradiation under 0.5W/m2 white light at room temperature the decrease of the resistivity as a result of light exposure is 18% for P3HT films and 20% for P3HT:PCBM blend films. By adding the fullerene molecules,


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in the 1:0.8 polymer:fullerene ratio, the electrical resistivity at room temperature of the blend films decrease compared to the polymer film by 40% in dark, by 35% under a irradiance of 0.5W/m2 white light and by 68% under 250W/m2 irradiance. The decrease of the resistivity with the temperature is more pronounced in the presence of light indicating a photon activated process.

The dependences of P3HT:PCBM blend films electrical conductivity during many successive cycles of heatings-coolings in dark followed by heating-cooling cycle under illumination, shows that the results are very reproducible and we distinguish very clear a difference between cycles under illumination and cycles in dark. For P3HT:PCMB films after irradiation, as in all photoconduction processes, the system needs some time to rest for coming back to the initial state. At the same irradiation, the photoelectrical properties of active layers remains stables during many cycles of heatings and coolings between 25°C and 120°C [1].

[1]. M.Girtan, Organic electronics 14 (1), (2013) p. 200 - 205

Keywords: organic solar cells, P3HT:PCBM

Abstract:0012

Theroretical and Experimental Studies on Evacuated Heat Pipe Solar Collector

Rania Ramzi, Samah Maalej, Mohamed Chaker ZaghdoudiLaboratoire Matériaux, Mesures et Applications (MMA), INSAT, Carthage University, Tunis, Tunisia

The paper deals with a theoretical and experimental study of an evacuated Heat Pipe Solar Collector (EHPSC) to be used for solar refrigerating machine.

In the theoretical part of this work, a mathematical model is developed in order to simulate the thermal performance of an EHPSC as a function of different operating conditions such as the solar irradiation, the water inlet temperature, and the water mass flow rate. The model also allows to determine the effect of geometrical parameters such as the heat pipe spacings, diameters, lengths, and numbers.

In the experimental part of the study, an EHPSC is developed and tested. It has 12 copper heat pipes filled with water and having a capillary structure made of helicoidal and trapezoidal capillary grooves, and Compound Parabolic Concentrator (CPC) type reflectors are used. The tests were performed under the meteorological conditions of Tunis, and several operating parameters such as the solar irradiation, the mass flow rate, and the temperature of water flowing through the HPSC are considered. For fixed operating conditions, the experimental results show that the instantaneous efficiency of the HPSC increases during the day. However, it decreases when water mass flow rate and temperature increase. The experimental thermal performance curves (efficiency vs. reduced temperature) allow for the determination of the optical efficiency as well as the solar collector heat losses coefficients.

The comparison between the theroretical simulations and the experimental results shows a good agreement in predicting the water outlet temperature and the EHPSC efficiency.


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Keywords: Heat pipe, Solar Collector, Evacuated tube, Efficiency

View of the EHPSC

Abstract:0015

Evidence of the Excitons Total Dissociation at the p-n Junction a Bilayer Heterojunction Organic Photovoltaic Solar Cell based

on CuPc and C60

Allé Dioum 1, Sossé Ndiaye 1, Mouhamed Bachir Gaye 1, Bassirou Lo 1, El Mahdi Assaid 2, Aboubaker Chédikh Beye 1

1Department of Physics, University of Cheikh Anta Diop, Dakar, Senegal2Department of Physics, University of Chouaib Doukkali, El Jadida, Morocco

Theoretical study of a 3-D modelled bilayer-Heterojunction Organic Solar Cell (bHJ-OSC) based on copper phthalocyanine (CuPc) as electron donor and fullerene (C60) as electron acceptor is reported. The thin film multilayer stacking theory is applied to the bHJ-OSC, with the optical matrix of the Abeles formalism leading to new expression of generation rate and density of exciton photogenerated in the organic photoactive layer of CuPc/C60. The excitons density is investigated considering the excitons dissociation parameters at the different interfaces of the organic photoactive region, i.e. the exciton dissociation velocities Sdp, Sdg, Sdj and Sdn respectively associated to the transparent anode (ITO: Indium thin oxide)/donor (CuPc), the donor (CuPc)/acceptor (C60) and the acceptor (C60)/metallic cathode (Al: aluminium) interfaces. Moreover, the influence of the monochromatic light wavelength λ and the thickness w of the organic photoactive layer (CuPc/C60) on the exciton density is emphasized.

Keywords: Bilayer Heterojunction, Organic Solar Cell, Exciton Dissociation


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3D Schematic of the bilayer heterojunction solar cell device based on CuPc/C60

Assumptions: - The different layers are homogenous and isotropic, - The refraction (n) and extinction (k) indexes are in constant values and independent on layer thickness w - The interfaces are planes, - The cross section is square with gx=gy (grain size) The excitons dissociation velocities are materialized by the parameters Sdp, Sdg, Sdj and Sdn, respectively associated to the anode/donor, perpendicular boundaries surfaces to the plan of p-n junction /incidence area, donor/acceptor and acceptor/cathode interfaces. The different excitons dissociation parameters chosen and defined as above are indicated in figure 1.

Exciton density photogenerated in the CuPc/C60 layer versus the logarithmic of exciton dissociation velocity Sdj at the p-n junction for different values of exciton dissociation velocity Sdn at the acceptor/cathode interface.

In order to check the competitive role of the exciton dissociation velocities Sdj, Sdp and Sdn at the various active interfaces, respectively at the p-n junction, the anode/donor and the acceptor/cathode, the exciton density photogenerated in the photoactive layer CuPc/C60 is plotted in figures 6 and 7 as a function of Sdj for different values of Sdp and Sdn.

Exciton density photogenerated in the CuPc/C60 layer versus the logarithmic of exciton dissociation velocity Sdj at the p-n junction for different values of exciton dissociation velocity Sdp at the anode/donor interface

- Evidence of the efficient exciton dissociation at the p-n junction or donor/acceptor. - 3D modelling study to determine new expression of excitons density photogenerated in the CuPc/C60 organic layer and exciton photogeneration rate. - Introduction of new parameters of excitons dissociation velocity assumed to the different surface and to the p-n junction or donor /acceptor interface.


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Excitons density distribution photogenerated in the photoactive layer (CuPc/C60)

The excitons density photogenerated in the organic photoactive layer CuPc/C60 presents a symmetrical distribution with respect to the z-axis perpendicular to the (gx, gy) plan of the p-n junction. This excitons distribution admits a maximum in the centre of the photoactive layer by presenting a stage (plate) parallely to the p-n junction surface which corresponds to a null gradient.

Excitons density photogenerated in photoactive layer (CuPc/C60) versus the cell’s dept z and the cross section size gx of the cell.

The density of the photogenerated excitons exhibit a maximum at the anode (ITO)/donor (CuPc) interface indicating that most of the excitons are created nearby the front surface. This density decreases very quickly until reaching a minimum quasi null near the p/n junction at z=0. Beyond the p/n junction, this density increases slightly towards the acceptor/cathode interface mostly as a result of exciton generation in this n-type region.

Abstract:0016

Analysis of Electrons Recombination effect on Excess Minority Density of a Bulk-Heterojunction Organic Solar Cell based on

blend of P3HT: PCBM in Transient Decay

Allé Dioum 1, Mouhamed Bachir Gaye 1, El Hadj Omar Guèye 1, Sossé Ndiaye 1, El Mahdi Assaid 2, Aboubaker Chédikh Beye 1

.....

The transient decay occurs between two steady states through operating points of a Bulk-Heterojunction Organic Solar Cell (BHJ-OSC) based on blend of poly (3-hexylthiophene-2, 5-diyl) (P3HT) as electron donor and a soluble derivative of fullerene called [6, 6]-phenyl C61-butyric acid methyl ester (PCBM) as electron acceptor with different thicknesses wb and under various values of a monochromatic


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illumination wavelength λ of the spectrum visible is investigated. Mainly, the influence of electrons recombination at the interfaces of the photoactive layer and the bimolecular recombination inside the blend upon to the excess minority electrons density photogenerated is reported. Attention is also paid to the dependence of the electrons life time, diffusion length, mobility.

Keywords: Organic Solar Cell, Bulk Heterojunction, Blend, Recombination velocity, Electron

Excess minority of electrons density photogenerated in the blend of P3HT: PCBM versus the transit time t for different different eightenvalues ω.

The decay of the excess of electrons photogenerated in the blend of P3HT: PCBM, decreases exponentially versus the transient time t until reaching a null value. In fact, the excess minority of electrons density decreases with the eigthenvalues ω included to the spatial part of the expression of the density in transient state. We can noticed, a predominance of the first order ω=0 which corresponds to fundamental level compared to other one (e.g. ω=1, 2…)

Excess minority of electrons density photogenerated in the blend of P3HT: PCBM versus the transit time t for different value of electron recombination velocity Sa at the anode/blend

The transient decay of this BHJ-OPV under constant illumination of a monochromatic wavelength λ=780 nm, increases with the electrons recombination at the anode/blend interface (figure 5). Thus, the electron recombination at the anode/blend interface acts very favourable to the electrons photogeneration in the bulk of the organic cell. Then, it seems that has a role of pumping system of the carrier (electron) resulting from the excitons dissociation photogenerated in the vicinity of the anode interface which recording the high absorption of the light (i.e. the front side directly illuminated).

Excess minority of electrons density photogenerated in the blend of P3HT: PCBM versus the transit time t for different value of electron recombination velocity Sc at the blend/cathode.

the transient decay both decreases very strongly with the electrons recombination at the blend/cathode interface


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Excess minority of electrons density photogenerated in the blend of P3HT: PCBM versus the transit time t for different value of electron recombination velocity Sg at the blend layer boundary.

the transient decay both decreases very strongly with the electrons recombination at the blend/cathode interface (figure 6) and the at the blend layer boundary (figure 7).

Excess minority of electrons density photogenerated in the blend of P3HT: PCBM versus the transit time t for different value of the bimolecular recombination coefficient relative to the electrons.

Analysis of the figure 8 shows that the bimolecular recombination acts very harmful on the excess minority of electrons density photogenerated in blend of P3HT: PCBM. Indeed, the aim of this study is not determine the bimolecular recombination but to show its influence. Thus we have confirm here once again the harmful effect of the bimolecular recombination on the BHJ-OPV performance.

Excess minority of electrons density photogenerated in the blend of P3HT: PCBM versus the transit time t for different value of the electrons diffusion length Ldiff.

the transient decay grows up strogly until reaching a m aximum versus the electron diffussion length Ln. The slowest values of Ln (Ln=45, 60, 75) inferior to the blend layer thickness wb record the weak values of the excess minority of electrons density with small transient time t (e.g. t>4µs). In fact, when the electron diffusion length is lower than the blend thickness wb, the carrier felt into a possible recombination before reaching the cathode to be collected.


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Excess minority of electrons density photogenerated in the blend of P3HT: PCBM versus the transit time t for different value of the electrons life time.

The excess minority of electrons density photogenerated in the bulk of P3HT: PCBM decreases exponentially versus the transit time t while it increases strongly with the electrons life time.

Schematic 3D bulk heterojunction solar cell device based on blend of P3HT: PCBM

Cartesian coordinate system (o,x,y,z) is associated to the photoactive layer in the centre of the anode (ITO)/blend (P3HT: PCBM) (red) interface. In figure 1 is shown the various parameters charge carriers recombination associated to each interface of the blend photoactive region. Hence: •Sa: electrons recombination velocity at the anode/blend interface •Sc: electrons recombination velocity at the donor (P3HT)/acceptor (PCBM) interfaces •Sg: electrons recombination velocity at the blend/metallic cathode (Al) interface

Abstract:0017

Effect of annealing on the physical properties of iron tin sulphide thin films

Meriem Reghima 1, Anis Akkari 1, Cathy Guasch 2, Michel Castagné 2, Najoua Kamoun Turki 1

1Laboratoire de Physique de la Matière Condensée, Faculté des Sciences de Tunis El Manar, Tunisie (2092), Tunisia.

2Institut d’Electronique du Sud, Unité Mixte de Recherche 5214 UM2-CNRS - Université Montpellier 2, Place Eugène Bataillon, Bat 21 cc083, F-34095 Montpellier Cedex 05 France.

This paper describes the effects of annealing on Fe-doped SnS thin films prepared by chemical bath deposition. The films were initially deposited onto Pyrex substrates, and followed by annealing at various temperatures ranging from 200 to 600 °C for 30mn in nitrogen gas. X-Ray diffraction analysis reveals that a structural transition from zinc-blend to orthorhombic occurred when the annealing temperature is over 500°C. The elemental composition of Sn and S performed by Energy Dispersive Spectroscopy


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are near to the stoechiometric ratio. Optical properties are studied by means of transmission T(λ) and reflection R(λ) measurements, and show the decrease of transmission with increasing annealing temperatures. The band gap energy is found to be in the range of 1.2-1.51 eV, which corresponds to the optimum for photovoltaic applications. Moreover, annealed Fe-doped SnS thin film exhibits a high absorption coefficient near to 105cm-1, indicating that it can be used as the absorbing layer in solar cells. Finally, using thermally stimulated current, it is found that electrically active traps located in the bandgap disappear after heat treatment at 500°C. Further investigations are in progress to include such absorbing layer in a solar cell structure.

Keywords: SnS; thin films; annealing

Abstract:0018

Effect of solution volume and N2 annealing atmosphere on the physical properties of Cu2ZnSnS4

Zeineb Seboui 1, Yvan Cuminal 2, Najoua Turki Kamoun 1

1Laboratoire de Physique de la Matière Condensée, Faculté des Sciences de Tunis El Manar, Tunisie (2092), Tunisia.

2Institut d’Electronique de Sud, Unité de Recherche 5214 UM2-CNRS - Université Montpellier 2 Place Eugène Bat 21 cc083F-34095 Montpellier Cedex 05 France.

Cu2ZnSnS4 (CZTS) thin films have been prepared on Glass substrates using a new solvent (Methanol) by Spray pyrolysis technique. In this work, we study the effect of the solution volume Vsp varying from 100 to 900 ml on structural properties of CZTS thin films (by X-ray diffraction XRD and Raman spectroscopy), morphological and compositional properties (by atomic force microscopy AFM and scanning electronic microscopy SEM) and optical analysis by spectrophotometry. Photoluminescence measurements have been also performed on Cu2ZnSnS4 crystals. Moreover, electrical studies were carried out using Hall effect measurements. X-ray diffraction pattern reveals the presence of kesterite structure with (112) preferential orientation for CZTS thin layers. Optical analysis by means of transmission T(λ) and reflection R(λ) measurements allow to determine the optical absorption coefficient α for all Cu2ZnSnS4 compounds, it is in the order of 104 cm-1. The direct band gap energy value can be deduced, it’s about of 1.52 eV, indicating that Cu2ZnSnS4 compound has absorbing properties favorable for applications in solar cell devices such as Cu2ZnSnS4/In2S3 in which In2S3 is used as optical window and has been well grown in our laboratory [1]. Broad emissions at around 1.27 eV was observed in the photoluminescence spectrum which is assigned to the donor acceptor pair (DAP) emission. Moreover, the effect of N2 annealing atmosphere on the physical properties of CZTS thin films grown at Vsp = 700 ml has been also investigated.

Keywords: Cu2ZnSnS4; absorber material; thin films; solution volume and annealing


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Abstract:0021

Preparation and characterization of photovoltaic structures in ZnO/ITO produced by electrodeposition

Mohamed Bouafia 1, Amel Bakhouche 1, Gerhard Gobsch 2

1Institute of optics and precision mechanics, University of Setif, Setif, Algeria2Institute of Physics, Technical university of Ilmenau, Ilmenau, Germany

In recent years, several studies and intensive research have focused on the development of nanomaterials for photovoltaics. The objective of our work is to contribute to a better control of morphological and optical properties of ZnO structures obtained by electrodeposition on ITO substrates.

Layers of different thicknesses (8 samples) were prepared by varying the electrodeposition time from 1000 to 5000s. The preparation procedure is the preparation of compact layers of ZnO by electro-deposition at low temperature (70 to 80 ° C). After the formation of the layer, the ZnO is electrodeposited from an electrolytic bath containing lower concentrations of Zn^2+) in a solution of KCl (0.1 moll^-1), the precursor being always molecular oxygen (O2).

For more information on the structure and morphology of the deposited layers atomic force microscopy (AFM) and X-ray diffraction (XRD) have been used.

The optical characterization was carried out simultaneously by spectroscopic ellipsometry in order to determine the optical constants, and by Fourier transform infrared spectroscopy (FTIR).

Keywords: photovoltaic, ZnO, ITO, electrodiposition, ellipsometry, AFM, XRD, FTIR

AFM

Ellipsometry


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FTIR

preparation

XRD


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Abstract:0022

Comparative study of Al-Si alloying and phosphorus diffusion gettering of iron in silicon wafers: simulation from impurity to

carrier lifetime

Nabil Khelifati 1, Djoudi Bouhafs 1, S E H Abaidia 2, Abd El Ghani Boucheham 1, Baya Palahouane 1, Messaoud Boumaour 1

1Photovoltaic Cells and Modules Department, Technology Research Centre for Energetic, Algiers, Algeria2Faculty of Science, M’hamed Bougara University, Boumerdes, Algeria

Crystalline silicon (c-Si) is currently the dominant material for photovoltaic solar cells industry. This is mainly due to its high energy conversion-manufacturing cost ratio as compared to other materials such as amorphous silicon (a-Si) or copper indium diselenide (CIS) thin films. However, the contamination of c-Si material by metallic impurities (Fe, Cr, Co, etc...) is considered as their major disadvantage. Indeed, the presence of such impurities can greatly limiting the efficiency potential of solar cells. Nevertheless, most metallic impurities can be partially removed from the bulk of a Si wafer, using extrinsic gettering method. It refers to a thermal process that activates the diffusion of interstitial impurities from the bulk of the wafer to less important superficial regions of high solubility. These regions are generally created by aluminum-silicon (Al-Si) alloying and/or by phosphorus in-diffusion (PD).

In this contribution, a comparative study of Al-Si alloying and phosphorus diffusion gettering of iron in c-Si wafers is presented. The study is carried out using simulation software developed in our Centre. The simulation allowed us follow the evolution of the interstitial iron content in c-Si wafers after each gettering method. Focus is set on the influence of different physical and processing parameters like initial impurity density, size of iron precipitates, Al-Si layer thickness, time and temperature of gettering. The obtained results showed the influence of these parameters on the bulk minority carrier lifetime (τb) and then can be considered as an important step towards the optimization of the experimental conditions of gettering process.

Keywords: Crystalline silicon, Iron, Extrinsic gettering, simulation

Abstract:0023

Characterisation and modeling of lead acid battery

Nadia Achaibou, Djamila Diaf, Walid Merrouche, Idir GaciCentre de Développement des Energies Renouvelables, CDER, Algiers, Alegria

Batteries remain a complicated element, since they are the only dynamic element in a PV system. In fact many phenomenons can occur such as charge and discharge. Many parameters vary during theses processes: voltage, current, density, temperature, resistivity…etc. This leads to a complicated behavior of this element and thus makes predictions of the state of charge much more complicated. Battery state of charge evolution usually consists of measuring manually the electrolyte density; this method can only be employed by people in charge of the maintenance of an installation and is not feasible for a private individual wishing to have at least daily information.


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The selected model is that elaborated by Cuasch. This model is general, it takes into account the discharge, the charge and the overcharge processes, and can be applied for wide range of lead acid batteries used in PV systems.

The Guasch model presents a good performance to represent dynamic and complex battery operation.

This paper reviews this general lead acid batteries model and it agreement with experimental data obtained from tests.

For checking the validity of the mathematical model, the results of numerical simulation are compared with experimental data of Varta Solar 100 Ah battery and Bergan Energy 100 Ah battery. We note easily that the correlation between measured data and those calculated by the Copetti model for ambient temperature of 25 °C is good.

Keywords: battery storage; battery modelling; PV system; lead acid battery

Abstract:0024

Determination of the Optimum Feed Water Depth of an Improved Solar Still

Ronald Makhole, Chifundo Tenthani, Amos MadhlopaUniversity of Malawi, The Polytechnic, Blantyre, Malawi

Solar distillation is a process of purifying water using solar energy. The equipment that does the process of distillation is called solar still. In this study three identical improved stills were tested under the same climatic conditions to determine the optimum feed water depth. The project was conducted at University of Malawi, the Polytechnic. Water was added to each of the three improved solar stills at different depths from 0.005m to 0.04m. The different feed water depths of these improved solar stills were recorded and the daily hourly and total distillate and temperatures of both the raw water in the basins and of the inside of the glasses was recorded for all the stills. The radiant energy reaching the solar stills was considered to be the one that was recorded at Chichiri Automatic Weather station by the Department of Meteorological. Thermometers were used to measure the temperatures and measuring cylinder was used to measure the distillate outputs. The depth of 0.02m was found to be the optimum depth of an improved solar still because of the large mean of distillate amount at this depth as compared to other selected depths which were used in this experiment. The average feed water temperature and condensing surface temperature were 65˚C and 55˚C respectively at optimum feed water depth. The average amount of distillate amount was 2.932 Kg/m2 while the average efficiency of the still was found to be 31.35%.

Keywords: improved solar stills, solar distillation, distillate


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Abstract:0025

Improvement and Performance Testing of Parabolic Trough Solar Cooker for Indoor Cooking

Haftom Asmelash Asmelash Weldekidan 1, Kimambo Cuthberth C.z.m 2

1Department of Industrial Engineering, Mekelle University, Ethiopia2Mechanical and Industrial Engineering, College of Engineering, Tanzinia

Fuel-wood scarcity is a growing problem that has so far been poorly addressed. Solar cooking is one possible solution but its acceptance has been limited partially due to low performance and convenience of use of most of the solar cookers that currently are available. The objective of this research is to increase the temperature of an already constructed concentrating solar cooker and hence the performance. A parabolic trough cooker (PTC), which the cooking section placed indoor whiles the collector part outdoor, have been constructed with soya bean oil conveying the energy between the two. These units are joined by insulated steel tubes. This arrangement allows cooking to be done indoors. In this way it will be possible to reduce the danger of getting burns and eye damages while cooking with it, thereby increasing the utilizability of the product. Ray tracing tests together with Standard Stagnation Temperature (SST) tests indicate that a 30mm diameter copper pipe is the optimum size for the absorber pipe. Some improvements were also made to the storage tank and cooking pot. Temperature readings were taken at different parts of the PTC. Maximum temperatures of 191 0C at the mid absorber pipe and 119 0C at the cooking stove were obtained during the SST and simulated load tests respectively. Finally the efficiency of the solar cooker has been calculated and found to be 6 %, which is twice as high as the previously constructed PTC.

Keywords: solar cooking, trough collector, stagnation test

Abstract:0028

Numerical Analysis of Thin-film Photovoltaic Solar Cells Using Maple

El Mahdi Assaid 1, Safae Aazou 1, Asmaa Ibral 1, El Mustapha Feddi 2

1Equipe d’Optique et Electronique du Solide, Département de Physique, Faculté des Sciences,Université Chouaïb Doukkali, B. P. 20 El Jadida principale, El Jadida, Royaume du Maroc.

2Département de Physique, Ecole Nationale Supérieure d’Enseignement Technique,Université Mohamed V Souissi, B. P. 6207 Rabat-Instituts, Rabat, Royaume du Maroc.

The present paper describes a method for solving numerically the one dimensional (1D) semiconductor steady-state equations in the case of a thin-film photovoltaic solar cell using Maple computer algebra software. The semiconductor equations solved are Poisson’s equation which is a non-linear ordinary differential equation coupled to the electron and hole continuity equations which are linear partial differential equations. Finite difference scheme and Gummel-Scharfetter scheme are used respectively to discretize symbolically Poisson’s equation and charge carriers continuity equations on a network


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of uniform meshes. The three difference equations are linearized and a numerical solution of the system of equations is calculated iteratively according to the Newton-Raphson algorithm and using the Successive Over-relaxation method for the resolution of Poisson’s equation. The numerical simulation code developed is used to determine electrostatic potential, electric field, total charge, electron and hole densities, bands diagram, and electrons and holes currents densities as functions of the depth in the optoelectronic device for a given doping profile across the p-n junction based photovoltaic solar cell.

Keywords : Numerical analysis, Computer-aided simulation, Finite difference scheme, Gummel-Scharfetter scheme, Successive over-relaxation method, Thin film photovoltaic solar cell.

Abstract:0031

Cu-Zn-Sn-S and Cu-Cd-Sn-S thin films prepared by non-vacuum processing

Fawzy Abdelhamid MahmoudFawzy A.Mahmoud

Cu-Zn-Sn-S and Cu-Cd-Sn-S thin films were synthesized by spray pyrolysis method. Transmission electron microscopy (TEM), scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),X-ray diffraction(XRD) and UV-vis-NIR absorbance spectroscopy measurements indicated that the Cu-Zn-Sn-S and Cu-Cd-Sn-S thin films have good crystalline quality. The band gap of Cu-Cd-Sn-S films is estimated to be ~1.3 eV while the band gap of Cu-Zn-Sn-S thin film is estimated to be 1.4.

Keywords: solar cell materials, low cost technique, thin film, absorbing layer

Abstract:0033

The Use Of Carbon Nanomaterials to enhance Solar Energy Systems

Rolant Eba MedjoUniversity of Douala

Carbon is one of the most abundant and fascinating elements on earth. It appears in several allotropes with widely different properties. Among these, are those discovered since 1985. These novel carbons attract intensive attention due to their fundamental and technological interests. They exhibit unique and unusual properties. Novel carbons are promising to revolutionize several fields of science and contribute as major component of nanotechnology. All of them are excellent electronic materials, and are candidates for the post-silicon age. They have enormous potential in electronic device community. The first two decades were devoted in production of high quality samples. Synthesis and characterization are almost concluded. Their unique and unusual properties be used in a wide array of


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practical applications. The overview of Energy environmental history suggests areas of research that should identify crucial points of imperious innovations. In purely scientist recent decades activities, one should realized that conversion of solar energy has been among the most important areas, due to the constantly growing of energy demand and problems relative to other energy production systems. For efficient and environmentally goals, artificial photosynthetic systems undergo cascades of light-induced energy and electron transfer reactions. The absorbed energy is converted into chemicals’. These events take place in organized arrays within specifically tailored environments. The development of absorbing molecules with appropriate absorptive properties for solar energy harvesting going over 20% (present average) is desirable. Carbon-based nanomaterials are designed at each level of solar energy conversion future schemes.

Keywords: Solar energy, Conversion, Novel carbons, Nanoscience and Nanotechnology

Abstract:0034

Influence of hot and dry climate on the reliability of lead acid solar battery

Etienne Tchoffo Houdji 1, Martin Kamta 2, Haman Djalo 1, Joseph Kayem 3

1Department of Renewable Energy, ISS -University of Maroua P.O.BOX 46, Cameroon2Electric Department of IUT, University of Ngaoundéré P.O.BOX 455 Ngaoundéré, Cameroon.

3Department of Processing engineering, ENSAI, University of Ngaoundéré P.O.BOX 455 Ngaoundéré, Cameroon

This paper presents the results of a statistical study of charge and discharge cycles of a lead acid solar battery in the hot and dry climate of Maroua, situated in the far north region of Cameroon. The solar battery is charged with photovoltaic solar panels and discharged in a temperature invariant resistive load. The battery voltage and current, the ambient temperature and the relative humidity of the air are instantaneously recorded by a data acquisition system. The exploitation of these data allows an estimation of the reliability the solar battery as a function of the ambient temperature and the relative humidity of the air.

Cette communication présente les résultats d’une étude statistique des cycles de charge/décharge d’une batterie solaire au plomb/acide en fonction des paramètres du climat chaud et sec de Maroua, Cameroun. La batterie solaire est chargée par un panneau solaire et déchargée sur une charge résistive invariante avec la température. Les niveaux seuils de tension de sortie de la batterie solaire, la température ambiante et le taux d’humidité relative de l’air sont enregistrés au fil du temps par un système d’acquisition de données. L’exploitation de la banque de données expérimentales a permis d’estimer la fiabilité de la batterie solaire en fonction de la température ambiante et du taux d’humidité relative de l’air.

Keywords: Photovoltaic System, Reliability, Lead Acid Solar Battery, Hot and Dry Climate

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Abstract:0039

Natural Pigment Sensitized Solar Cells Based On Zno/Tio2/Fe2o3 Nanocomposite

Chalachew Mebrahtu Asmelash 1, Abi Taddesse Mengesha 1, Girma Goro Gonfa 2, Teketel Yohannes Anshebo 3

1Department of Chemistry, Haramaya University, Dire Dawa, Ethiopia2Department of Physics, Haramaya University, Dire Dawa, Ethiopia

3Department of Chemistry, Addis Ababa University, Addis Ababa, Ethiopia

Ten nanocomposites of zinc-titanium-iron oxide with different ratios of precursor salts were prepared by co precipitation method to use as semiconductors for dye sensitized solar cell. The structural properties of all the as-synthesized powders were examined using XRD through which four of them were selected based on their smallest size. The selected nanosized powders were further characterized using EDS, SEM TEM. UV- vis spectroscopic technique was employed to estimate band-gap energies of prepared nanopowders. The particle sizes were calculated and compared with TEM and XRD results. A solid state photoelectochemical cell based on the selected four nanoparticles sensitized with N719 dye has been constructed and characterized. The current density-voltage characteristics in the dark and under white light illumination and action spectra under monochromatic illuminations have been studied. The stability as well as solar energy conversion efficiency of the as-synthesized semiconductors sensitized by the commercial dye was obtained in the following order: C1<C3<C6<C10. Natural pigments were also extracted using ethanol and water solvents from Guizotia Scabra, Spathodea Nilotica, Salvia Leucantha and Lantana Camara to use as sensitizers. Absorption spectra of the natural dyes were measured and all ethanol extracts of natural sensitizers absorbs in the visible region. Dye sensitized solar cells were constructed using all the natural pigments and four semiconductors. The following best device parameter was achieved by the ethanol extract of Salvia Leucantha and ZnO/TiO2/Fe2O3 nanocomposite semiconductor when the potential is scanned: a Voc of 250 mV, Jsc of 0.014 mAcm-2 at light intensity of 100 mWcm-2.

Keywords: Co-precipitation, semiconductor, dye sensitized solar cell, natural pigments, conversion efficiency


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Abstract:0041

Influences of surface roughness of ZnO electron transport layer on the photovoltaic performance of organic inverted solar

cells

Zaifei Ma 1, Zheng Tang 1, Ergang Wang 2, Mats R. Andersson 2, Olle Inganäs 1, Fengling Zhang 1

1Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden2Department of Chemical and Biological Engineering/Polymer Technology, Chalmers University of

Technology, Göteborg, Sweden

Inverted organic solar cells (ISCs) taking ZnO as electron transport layer (ETL) has been extensively researched due to not only ZnO can considerably improve the stability of the SCs but also ZnO is cheap, environmental-friendly and roll-to-roll processing compatibility.1 Furthermore, the PCE obtained from ISCs based on ZnO is as high as that of conversional OSCs.2 However, the reports about how the surface roughness of the ZnO interlayer influences the performance of the ISCs are limited. Thus we demonstrate the correlation between the surface roughness of the ZnO interlayer used as ETL in ISCs and the PV performance of the ISCs.3

In this work, three different surfaces of the ZnO ETL are studied in ISCs with the polymer poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl] (TQ1) mixed with PC71BM as the active layer. The results obtained from these ISCs show that PCE increases from 2.7% to 3.9% when the root mean square (RMS) roughness of the ZnO layer decreases from 48 nm to 1.9 nm, due to the increased donor-acceptor interfacial area in the active layer and decreased effective interfacial area between photoactive layer and ZnO layer.

1. Krebs, F. C.; Gevorgyan, S. A.; Alstrup, J. J. Mater. Chem.2009, 19, 5442.2. Cephas E. Small; Song Chen; Jegadesan Subbiah; Chad M. Amb; Sai-Wing Tsang; Tzung-Han Lai; Reynolds, J. R.; So, F. Nat. Photonics 2012, 6, 6.3. Ma, Z. F.; Tang, Z.; Wang, E. G.; Andersson, M. R.; Inganas, O.; Zhang, F.L.J. Phys. Chem. C 2012,116(46),24462.

Keywords: Inverted organic solar cells (ISCs), ZnO, electron transport layer (ETL), surface roughness, photovoltaic performance


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Abstract:0045

Optimization of organic solar cells based on triphenylamine used as donor of electrons

Mohammed Makha 1, Mohammed Addou 1, Linda Cattin 3, Mostapha Morsli 3, Jean Chritian Bernede 2

1Laboratoire Optoélectronique et Physico-chimie des Matériaux, Université Ibn Tofail, Faculté des Sciences Kenitra 14000, Morocco

2Institute of Molecular Technology MOLTECH Anjou, University of Angers, Angers 49000 France.3Institut of material of Nantes IMN, University of Nantes, Nantes, F-44000 France.

We investigate the effect of anode buffer layers (ABLs) on the performances of multilayer heterojunction solar cells with thienylenevinylene triphénylamine with peripheral dicyanovi-nylene groups (TDCV–TPA) as donor material and fullerene C60 as acceptor.

The deposition of a CuI layer between the ITO anode and the electron donor significantly im-proves the short circuit current density (Jsc) and fill factor (FF) but reduces the open circuit voltage (Voc). On the other hand, a MoO3 buffer layer increases the Voc but leads to limited Jsc and FF values, thus reducing power conversion efficiency (PCE) (Fig. 1).

In this context, we show that the use of a hybrid anode buffer layer MoO3 /CuI leads to a considerable improvement of the cells performances and a PCE of 2.50% has been achieved. These results are discussed on the basis of the dual function of MoO3 and CuI. While both of them reduce the hole injection barrier, CuI improves the conductivity (Fig. 2) of the organic film through an improvement of molecular order while MoO3 prevents leakage current through the diode. Finally the results of a cursory study of the ageing process provide further support to this interpretation of the effects of the various buffer layers.

Keywords: Organic solar cells, triphenylamine, hybrid buffer layer, CuI, MoO3, hole only,

Abstract:0048

LaF3 Cathode-Buffer Layer for the Enhancement of Ehotocurrent in Organic Solar Cell

Abu Bakar Md Ismail, Md.shahinul IslamDept. of Applied Physics & Electronic Engineering, Rajshahi University, Rajshahi 6205, Bangladesh

Using LaF3 as electrode buffer layer investigation on the electric performances of organic solar cells (osc) has been presented. OSC has been fabricated using the conventional photoactive polymer blend (P3HT (poly (3-hexylthiophene)) and PCBM (Phenyl C61 butyric acid methylester at 1:1 ration). E-beam evaporated indium tin oxide (ITO) has been used here as the anode. Thin lanthanum fluoride (LaF3) between the Al cathode and photoactive material has been deposited also by e-beam-evaporation. So far in our knowledge, for the first time, the investigation on the thin layer of LaF3 between P3HT: PCBM and Al layer for the performance enhancement of OSC, has been investigated in this report. For various


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reasons LaF3 has been chosen as the buffer layer between P3HT: PCBM and Al. A very smooth surface with an average roughness of 2 nm has been observed by the Atomic Force Microscope (AFM). The LaF3 layer was found to increase the photocurrent and hence the efficiency of OSC. Various thicknesses of LaF3 layer have been investigated, and 3nm thick LaF3 layer was found to be the optimum thickness for the enhancement of photocurrent. Despite the high series resistance several order of photocurrent enhancement has been reported.

Keywords: Organic solar cell, Cathode buffer layer, photocurrent

Fig1. LaF3 layer thickness optimization for Open-circuit voltage

Fiig-2: LaF3 layer thickness optimization for short-circuit current


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Abstract:0053

Preparation and Utilization of TiO2-clay composite in Dye Sensitized Solar Cell

Is Fatimah 1, Basitoh Djaelani 1, Tatang Shabur Julianto 1, Imam Sahroni 1, Indriana Kartini 2, Cahyorini Kusumawardani 3

1Department of Chemistry, Universitas Islam Indonesia2Department of Chemistry, Gadjah Mada University, Indonesia

3Department of Chemistry, Yogyakarta State University, Indonesia

In present work, the combination of TiO2-clays and extract of Pericarp Garcinia mangostana L.(mangosteen) in dye sensitized solar cell system is studied. Purpose of research is to synthesize TiO2 nanoparticle in clay matrix as effort to increase semiconductor properties and utilize dye component of mangosteen pericarp in combination to trap light and convert it to clean and renewable energy. Preparation of TiO2-clay was conducted by sol-gel TiO2 pillarization process using varied concentration of titanium isopropoxide as a precursor. As raw material, acid activated-natural montmorillonite was utilized in comparison with the synthetic hectorite in the same pillarization procedure. All synthetic TiO2-clay minerals, the latter including TiO2 procured from commercial sources were characterized by powder X-ray diffraction (XRD), Scanning Electron Microscope(SEM), BET surface area diffuse reflectance UV-Visible. As sensitizer for DSSC testing, anthocyanin dyes extracted from mangosteen pericarp and synthetic dye of rhodamin B were used.

The results showed that TiO2-clay materials have physicochemical properties including porosity and chemical stability and ability to absorb light to be included as electrode in DSSC system. The combination of TiO2-clay with mangosteen pericarp extract demonstrated photoactivity in DSSC system at the minimum Ti content of 10%wt and by comparing both kind of clay minerals, hectorite exhibits higher efficiency (0.04%) compared to acid activated montmorillonite clay minerals (0.03%). These data was initial step for further experiment on TiO2 composite utilization in more economical way instead of bulk TiO2 nanoparticle.

Keywords: Dye sensitized solar cell, Garcinia mangostana L., TiO2/Montmorillonite, Photovoltaic properties

Abstract:0054

Modeling and simulation of solar Photovoltaic house in Sahara area

Benatiallah Ali, Harrouz Abdelkader, Abiadi Fatima, Benatiallah DjeloulAdrar University

Electric energy consumption in the arid Saharan regions is continuingly increasing due to increasing urbanization. Photovoltaic solar energy may be a suitable form of alternative electric energy production due to the abundance of solar energy in this region.


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In this paper we are presenting the general outline of a simulation model used to size and assess the performance a PV installation using DELPH5 programming language. This program allows the user to determine at any moment the performance of the PV installation by comparing the PV electric energy produced and the required consumption load and. It also permits the optimization of the system relative to the factor of time.

Keywords: PV system, modeling, climat effect, optimisation

Abstract:0056

Construction And Evalauation of A PV/T Collector Under Low Concentration Using The Batch Method

Samukonga G. 1, S. Hatwaambo 1, K. Hansingo 1

Department of Physics, Box 32379,University of Zambia

Photovoltaic cells are generally made from doped semiconductors whose conductivity decrease with increase in temperature. It is anticipated that by suppressing the rise in temperature for cells under concentration by using hot water could improve the overall efficiency of the photovoltaic-thermal system. Concentrator photovoltaic-thermal (PVT) hybrid collectors could reduce the cost of solar cells by reducing the solar cell area and employ cheap booster reflectors. The advantage of the water batch method is that transfer fluid in PVT can easily reach practical values of 50oc and above. The thermal energy extracted by the cooling fluid (water) can be used for other purposes. The maximum achieved power output from the PVT was 23W compared to the rated value of 18W. The thermal efficiency reached a maximum of 71.80% while electrical efficiency increased to a maximum value of 23% from a standard reference value of 14% for mono-crystalline solar cells. We observed that thermal and electrical efficiency decreased exponentially with increase in outlet temperature beyond 42oC. Therefore, the stagnant temperature of the prototype was 420C. We also observed that the wind profile is important when designing a PV/T system because high wind profiles favour electrical efficiency than thermal output due to high thermal losses through convection and radiation at high wind speeds.

Keywords: PV/T, Stagnant temperature, Batch method, Compound parabolic concentrator.


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Abstract:0059

Application of the extracts of calyxes of Hibiscus Sabdariffa and leaves of Azardirachta Indica as sensitizers in Dye-

sensitized solar cells

Adenike Omotunde Boyo 1, Paul Ndudim Okafor 1, Surukite Oluwole 1, Ibrahim Abudusalam 2

1Lagos State University,Ojo,Lagos,Nigeria2Fountain University, Oshogbo, Lagos, Nigeria

In this study we explored the application of the methanolic extracts of the calyxes of Hibiscus sabdariffa (H. sabdariffa) and leaves of Azardirachta Indica (A. Indica) as sensitizers in dye-sensitized solar cell (DSSCs). The pHs of the extracts were adjusted to become more acidic (normal pH to pH 3, and then pH 1) and their absorptions were determined at different wavelengths from 350 to 1000nm using spectrophotometer.

The cells were assembled using TiO2 thin films on FTO coated glass. The obtained solar energy conversion efficiency was 0.002 % and 0.00017 % for H. sabdariffa and A. Indica respectively. We found the fill factor (FF) for the cells made with H. sabdariffa 0.739, current density of 0.01mA/c m², and Voc of 0.0124volts and for the Azardirachta indica sensitized solar cells, 0.4, 0.0075mA/cm² and 0.0138volts were found respectively. The FF and efficiency of Hibiscuss sabdariffa extract is higher than that of Azardirachta indica sensitized solar cell. This might be due to the abundance presence of anthocyanins in Hibiscuss sabdariffa and minimal internal looses in the junction of the cell.

The above data show that extracts of the calyxes of Hibiscuss sabdariffa seems more reliable and more promising than extracts of leaves of Azardirachta indica as sensitizers in dye-sensitized solar cells.

Keywords: dye-sensitized solar cell, solar light energy conversion, TiO2,Hibiscus sabdariffa, Azardirachta indica

Abstract:0060

Solar ThermalL a Potential Injera Baking Pwer IN Ethiopia

Asfafaw Haileselassie Tesfay 1, Ole Jørgen Nydal 1, Mulu Bayray Kahsay 2

1Department of Energy and process Engineering, Norwegian University of Science and Technology, Trondheim Norway

2Department of Mechanical Engineering, Mekelle University, Mekelle, Ethiopia

Ethiopia with a population of about 85 million meets 96% of its energy need with bio-mass, charcoal, wood, animal dung and plant residues. More than 50% of this energy goes entirely on baking of Injera. Injera the national food of the country demands 180-220 degree C to be well cooked. This high temperature demand cited in literature’s was not supported by experiments and vary from place to place. In this article Injera baking practice with solar energy collected by a polar mount fixed focus parabolic dish concentrator with steam as heat transfer fluid (HTF) was discussed. The status of electric


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powered baking stoves and sustainability of solar power stoves has been discussed. The research and development of solar thermal application for direct household energy consumption was not well accepted for decades. The main obstacle to this was due to the limit of design to on focus application during sun shine time and energy utilization option was limited to outdoor cooking practice. In addition to the off-focus solar thermal application this paper discussed the integration of solar thermal with heat storage for a sustainable future use. The prototype for direct steam based baking was developed and tested in Mekelle University (Ethiopia) and Phase change material based heat storage prototype was developed and tested at NTNU. Both experiments showed the possibility of solar energy for Injera baking and its sustainability by synchronizing latent heat storage. The bottleneck problem for direct focus cooking has been solved successfully in this research work.

Keywords: Steam based Injera baking, solar Injera baking, PCM heat storage

Abstract:0062

The main objectives of the work described in this paper to model and simulate the autonomous hybrid photovoltaic wind

generator with battery storage (PV/WG). The more accurate and practical mathematic models for characterizing PV

module, wind generat

Benatiallah Ali, Abadi Fatima, Benatiallah DjeloulLeesii Faculty Of Science & Technolgy Adrar University

The main objectives of the work described in this paper to model and simulate the autonomous hybrid photovoltaic wind generator with battery storage (PV/WG). The more accurate and practical mathematic models for characterizing PV module, wind generator and battery storage are adopted, combining with hourly measured meteorological data and load data.

The performance of hybrid systems consisting of different rated power wind generator, PV areas and storage battery are presented.

The hourly average energy generated for the above hybrid system configuration has been compared with hourly load data of typical house.

The hybrid systems considered in the present study consist of a Fortis Espada 800 Watt wind generator, 11 Siemens SP35 (35W) PV panels supplemented with 6 battery storage unit for 1 day autonomy rate. The load is a rural house with 650 Watt.

Modelling and optimization Simulation is performed in a Matlab software environment.

Keywords: optimization solar wind system


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Abstract:0065

Wet-processable electron-transport materials for high-performance polymer light-emitting and photovoltaic devices

Dongcheng Chen, Hua Ye, Shijian SuState Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic

Materials and Devices, South China University of Technology, Guangzhou 510640, China

A new family of neutral alcohol-soluble small molecular materials comprised of electron-rich triphenylamine (TPA) and fluorene featuring phosphonate side chains (FEP) is reported, namely 3TPA-FEP, 2TPA-2FEP and TPA-3FEP, which have different TPA and FEP contents (Scheme 1). Due to their good solubility in polar solvents like alcohol, multilayer optoelectronic devices can be fabricated by a wet process from orthogonal solvents. Polymer light-emitting devices with these materials as a cathode interlayer and Al as the cathode show greatly enhanced efficiencies in contrast to control devices without such a cathode interlayer, and their efficiencies are comparable with or even higher than devices with the low work-function metal Ba/Al as the cathode. In addition, high-performance polymer solar cells based on the poly[N-9’’-hepta-decanyl-2,7-carbazole-alt-5,5-(4’,7’-di-2-thienyl-2’,1’,3’-benzothiadiazole)] (PCDTBT):[6,6]-phenyl C71-butyric acid methyl ester (PC71BM) system are also achieved with power conversion efficiencies of 7.21%, 6.90% and 6.89%, by utilizing 3TPA-FEP, 2TPA-2FEP and TPA-3FEP as the cathode interlayer, respectively. These efficiencies are also much higher than those for control devices without the cathode interlayer. Although TPA is well-known as a hole-transport unit, the current findings indicate that alcohol-soluble TPA-based small molecules are also a promising cathode interlayer for both electron injection and extraction.

Keywords: alcohol-soluble small molecule; cathode interlayer; polymer light-emitting device; polymer solar cell

Scheme 1. Molecular structures of 3TPA-FEP, 2TPA-2FEP and TPA-3FEP


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Abstract:0067

Impedance spectroscopy in lightly doped poly (3-hexylthiophene) devices

P. Anjaneyulu, C. S. Sangeeth, Reghu MenonDepartment of Physics, Indian Institute of Science, Bangalore 560012, India

Poly (3-hexylthiophene) is one of the important material for organic solar cell, and its electrical properties characterization is quite important to understand the performance of these devices.

Carrier density dependent impedance and current-voltage (I-V) measurements were carried out in poly (3-hexylthiophene) devices with both silver and platinum contacts. By varying the carrier density the devices shown deviation from simple RC circuit model which is due to the distributed relaxation time of carriers. The impedance measurements could identify and distinguish the metal-polymer interface. At higher carrier density, a simple RC circuit is enough to explain the impedance data; however, at lower densities a constant phase element (CPE) is required to model the data. This CPE indicates the presence of either distributed trap density or nanoscopic scale variations in the conductivity within the sample. It is observed that as the carrier density is varied the conduction mechanism changes accordingly, which is consistent with the I-V measurements.

Keywords: Impedance spectroscopy in lightly doped poly (3-hexylthiophene) devices

Abstract:0068

Study of physical properties of some transparent oxide semiconductors obtained by thermal oxidation of metallic thin

films

Sorina Iftimie 1, Julien Merigeon 2, Adrian Radu 1, Stefan Antohe 1, M. Kompitsas 3, Mihaela Girtan 2

1Faculty of Physics, University of Bucharest, Romania2LPHIA Laboratory, LUNAM - Angers University, France

3National Hellenic Research Foundation, LATA Laboratory, Athens, Greece

Different metallic (In:Sn, Ti, Ti:Nb, Zn, Zn:Al, Ni) thin films were directly oxidized by thermal treatment to obtain transparent conductive oxides with important electronic and optoelectronic applications. All samples were optical, structural, morphological and electrical characterized, before and after oxidation. The optical investigations were performed using a Perkin Elmer 19 UV-VIS spectrophotometer, transmission and absorption spectra being drawn, at room temperature. The crystalline structure was determined by X-ray diffraction using a Bruker D8 diffractometer and the morphological investigations were made using atomic force microscopy (LP Research Thermomicroscope Autoprobe microscope) and scanning electron microscopy (JEOL microscope). Hall measurements were performed for the oxidized thin films in 7 – 300K range. The goal of this study is to obtain very easy metallic oxides that can be used in transparent electronics applications and optoelectronic devices, particularly photovoltaic cells.


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Acknowledgments: S.I. is grateful to the Pays de la Loire and Angers University for the post-doc fellowship No 2012-12029 financial support and wants to thank Dr. Flavia Pop (Moltech Laboratory, Angers University) for fruitful discussions.

Keywords: metallic thin films, TCO, photovoltaic cells

Abstract:0075

Attempt to manufacture a solar cell by using a simple method of n-type doping of monocrystalline silicon

Diouma KoborDepartment of Physics, Assane Seck of ziguinchor, Ziguinchor, Senegal

The electrical behavior of a semiconductor device depends strongly on the distribution of the dopants within the structure. To make solar cells from monocrystalline silicon, it is necessary to realize a pn diode by implanting phosphorus atoms mainly on a given thickness of the p-type. Different liquid, solid, or gaseous methods are used. These methods often require equipment not available for underdeveloped countries.

In this work, we try to make mono-Si solar cells using an easier doping method. We combined spin-coating thin film deposition method and solid doping technique.

There are many ways of making thin films that can be classified into physical and chemical ways. The best known methods as regards the physical ways are sputtering, thermal evaporation, etc.. These methods require expensive equipment.

In our study, two phosphorous-based gel compounds are prepared and deposited by spin coating. Heat treatment would thus, after deposition of thin layer, diffuse phosphorus atoms into the substrate to obtain a pn diode. Secondary Ions Mass Spectroscopy (SIMS) was used to determine the phosphorus diffusion length and concentration. I-V measurements characteristics in dark and under illumination of 1000 W give curves close to a pn diode behavior.

Keywords: Monocristalline silicon, doping, spin coating, thin film, solar cell.

Phosphorus content characterization by SIMS


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Abstract:0077

Conversion of Majority-Carrier Polarity in Solution-Sheared Ambipolar Field-Effect Transistor Based on Diketopyrrolopyrrole

(DPP) with Thermally Removable Groups

Changduk Yang 1, Junghoon Lee 1, A Reum Han 2, Jonggi Kim 1, Yiho Kim 1, Kyu Cheol Lee 1, Dohyuk Yoo 1, Gitish K. Dutta 1, Shanshan Chem 1, Gyoungsik Kim 1,

Joon Hak Oh 2

1Interdisciplinary School of Green Energy, Ulsan National Institute of Science and Technology (UNIST)2School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology

(UNIST)

A narrow bandgap polymeric semiconductor, BOC-PTDPP, comprising alkyl substituted diketopyrrolopyrrole (DPP) and tert-butoxycarbonyl (t-BOC)-protected DPP, is synthesized and used in organic field-effect transistors (OFETs). The polymer films are prepared by solution deposition and thermal annealing of precursors featuring thermally labile t-BOC groups. The effects of the thermal cleavage on the molecular orientations in the polymer thin films are investigated using thermogravimetric analysis (TGA), UV-vis spectroscopy, atomic force microscopy (AFM), Fourier transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD) analysis. Upon utilization of solution-shearing process, integrating the ambipolar BOC-PTDPP into transistors shows p-channel dominant characteristics, resulting in hole and electron mobilities as high as 1.32x10-2 cm2V-1s-1 and 2.63x10-3 cm2V-1s-1. Very intriguingly, the dominant polarity of charge carriers changes from positive to negative after the thermal cleavage of t-BOC groups at 200 oC. The inverter constructed with the combination of two identical ambipolar OFETs exhibits a gain of ~10. Reported here for the first time is a viable approach to make use of solution-shearing technique as applied to a polymeric system. Furthermore, this work highlights the electronically tunable ambipolarity of thermocleavable polymer by simple thermal treatment.

Keywords: diketopyrrolopyrrole, tert-butoxycarbonyl (t-BOC), Ambipolar Field-Effect Transistor

Abstract:0081

Understanding the crystal structure and microstructure of solution processed Cu2ZnSnS4 absorber material using

Transmission Electron Microscopy

Nessrin Awadhullah Kattan 1, David Cherns 2, Bo Hou 3, David Fermin 3

1Bristol Centre for Functional nanomaterial, University of Bristol, Bristol, UK2Department of physics, University of Bristol, Bristol, UK

3Department of Chemistry, University of Bristol, Bristol, UK

In the last two decades, intensive studies curried out on Cu2ZnSnS4 as an ideal alternative absorber layer for photovoltaic devices due to their low cost, abundance and safety to the environment. Cu2ZnSnS4 was synthesized by hot injection method. Crystal structure of as-synthetic material and after annealing was analyzed by selected area and convergent beam electron diffraction techniques.


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TEM is an accurate technique to identify the actual phase of the material since other methods such as X-ray diffraction and Raman spectroscope are controversial. Diffraction patterns of crystalline material confirmed CZTS phase showing superlattice reflections extended along [001] c-axis which reveal to a tetragonal unit cell. Furthermore, Superlattice domains observed in bright field and dark field TEM images that extended parallel with the tetragonal c-axis.

Since it is important to synthesize a good quality of material to improve the performance of solar cell devices, we studied the microstructure and types of defects formed in CZTS nanocrystals using bright field and dark field techniques. In the post annealed stage, the material shows grow of lamellar twin on [111] plane accompanying with forming dislocations at [002] plane that create angle of 70.5⁰ between these two types of defects. This level of defects is not very harmful to the carrier transport as TEM analysis shows low defects density grown in the crystalline material. This study aimed to understand types of defects grown in polycrystalline and crystalline CZTS which could help in improving the quality of absorber material by controlling defects formation during the syntheses process.

Keywords: Cu2ZnSnS4, Kesterite, hot injection method, Electron microscopy.

SAED

SAED pattern of CZTS at [001] plane

Abstract:0083

Simulation studies of a novel Solar GAX cooling system

Daniel Sauceda 1, Nicolas Velazquez 2, Jesus Garcia 2

1Faculty of Engineering, Autonomous University of Baja California, Mexico.2Engineering Institute, Autonomous University of Baja California, Mexico.

A simulation study on a novel solar driven advanced absorption cooling cycle for air conditioning applications is presented, the system uses ammonia-water as working fluid and the generator is a parabolic trough solar collector coupled directly to the cooling cycle, these way, least one heat exchanger is eliminated and the overall efficiency of the system is increased. The collector mass flow rate has been optimized for maximum efficiency and lower generator temperature. The ambient temperature, the low and high pressure of the system, and the temperature of the chilled water have also been studied. The obtained results are compared to previous studies and it is found that the Solar COP of the novel configuration is 20% higher than that of a solar system indirectly coupled, the optimum mass flow rate


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of the collector varies depending of the solar beam radiation and ambient temperature moreover is recommended a control system to adjust this parameter

Keywords: Absorption refrigeration, GAX cycle, Solar cooling, parabolic trough

Abstract:0084

Light trapping with high diffuse reflectance dielectric scatterers in organic single and tandem junction solar cells

Zheng Tang, Anders Elfwing, Jonas Bergqvist, Wolfgang Tress, Olle InganäsBiomolecular and Organic Electronics, IFM, and Center of Organic Electronics, Linköping University, SE-581

83 Linköping, Sweden

In this work, we demonstrate efficient dielectric scatterers based on a mixture of TiO2 nanoparticles and polydimethylsiloxane (PDMS) for light trapping in semitransparent organic solar cells. An improvement of 80% in photocurrent of an optimized semitransparent solar cell is achieved with the dielectric scatterer with ~100% diffuse reflectance for wavelengths larger than 400 nm. We also demonstrate that for a parallel tandem solar cell, the dielectric scatterer generated 20% more photocurrent compared with a silver mirror beneath the cell; and for a series tandem solar cell, the dielectric scatterer can be used as a photocurrent balancer between the sub-cells with different photo-absorbing materials. The power conversion efficiency (PCE) of the tandem cell in series configuration with balanced photocurrents of the sub-cells exceeds that of the optimized standard solar cells. The characteristics of PDMS, such as flexibility and ability to stick conformably to surfaces, also remain in the dielectric scatterers fabricated in this work, which makes the demonstrated light trapping configuration highly suitable for large scale module manufacturing of roll-to-roll printed organic single or tandem junction solar cells.

Keywords: Light trapping, Light scattering, organic solar cells, semitransparent solar cells, tandem solar cells

TOC


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Abstract:0085

Conceptual Design and Simulation of a Small Mobile PV Driven RO Water Desalination Plant to be Deployed at the North West

Coast of Egypt

Hosam Shawky1, Amr Abdel Fatah2, Moustafa Said1, Abdel Hameed El Aassar1

1Desert Research Center, Cairo, Egypt2Arab Organization for Industralization, Cairo, Egypt

Water desalination projects based on reverse osmosis technology are being introduced in Egypt to combat drinking water shortage in remote areas. Reverse osmosis (RO) desalination is a pressure driven process. This paper focuses on the design of an integrated brackish water and seawater RO desalination and solar Photovoltaic (PV) technology. A small Mobile PV driven RO desalination plant prototype without batteries will be designed. Solar-driven reverse osmosis desalination can potentially break the dependence of conventional desalination on fossil fuels, reduce operational costs, and improve environmental sustainability. Moreover, the innovative features incorporated in the newly designed PV-RO plant prototype are focusing on improving the cost effectiveness of producing drinkable water in remote areas. This is achieved by maximizing energy yield through an integrated automatic single axis PV tracking system with programmed tilting angle adjustment. An autonomous cleaning system for PV modules is adopted for maximizing energy generation efficiency. The prototype will comprise a PV cooling system by feed water preheating leading to improved permeate production and improved energy yield. RO plant components will be selected so as to produce 1-3 m3/day of potable water. A basic criterion in the design of this PV-RO prototype is to produce a minimum amount of fresh water by running the plant during peak sun hours. Mobility of the system will provide potable water to isolated villages and population as well as ability to provide good drinking water to different number of people from any source that is not drinkable.

Keywords: Conceptual design, Reverse osmosis, photo voltaic, Desalination, Egypt

Abstract:0086

Economic Analysis of a Stand-Alone Reverse Osmosis Desalination Unit Powered by Photovoltaics for Possible

Application in the North West Coast of Egypt

Dalia AbozaidDesert Research Center, Cairo, Egypt

The availability of fresh water and energy is the key factor in the development of many countries. Potable water supply shortage and recent technological development have led to wider application of conventional, the growing potable water demand in NorthWest Coast of Egypt led to an organized national plan for implementation of desalination technologies. Today, current desalination methods require large amounts of energy, which is costly both in environmental pollution and in money terms. This paper presents the current research activities to establish the appropriate technology


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for adaptation, local manufacturing experiences, unit size, process, economics and cost effective battery less mobile photovoltaic powered groundwater reverse-osmosis (PV-RO) desalinating unit (autonomous desalination system).

Keywords: Economic analysis, Stand-Alone, Reverse osmosis, photo voltaic, Desalination, Egypt.

Abstract:0088

Influence of the performance of an indirect solar dryer by the oriention of the drying air flow

Tchaya Guy Bertrand1, Kamta Martin2, Kapseu César3

1Renewable Energy Department, ISS – the University of Maroua P.O Box 46 Cameroon2 Electric Department, IUT- the University of Ngaoundéré P.O Box 455 Ngaoundéré, Cameroon.

3Engineering Process Departments, ENSAI- the University Ngaoundéré P.O Box 455 Ngaoundéré

This paper presents a comparison of the measurements of temperature and relative humidity in an indirect solar dryer with forced convection, when the flow is either licking or traversing, or mixed. The experimental dryer is equipped with a mechanical system for guide manualy the drying air flow. The experimental results show that the performance of indirect solar dryer is influenced by the mode of circulation of the drying air.

Keywords: Optimisation, séchage, séchoir solaire indirect,

Abstract:0090

Photoelectrical performance in dye-sensitized solar cells with single-walled carbon nanotubes photoanodes

Mürsel Ekrem1, Emre Ünver2, Savaş Sönmezoğlu3, Ahmet Avcı4

1Department of Mechanical Engineering, Necmettin Erbakan University, Konya, Turkey2Graduate School of Natural and Applied Sciences, Selcuk University, Konya, Turkey

3Department of Materials Science and Engineering, Karamanoğlu Mehmetbey University, Karaman, Turkey4Department of Mechanical Engineering, Selcuk University, Konya, Turkey

Dye-sensitized solar cells (DSCs) have attracted considerable attention since they emerged as promising next-generation solar cells with low cost and high efficiency. Apart from the optimization of the nanostructure for light harvesting, an artificial design related to electron transport and recombination at the photoanode is particularly significant for efficient collection of photogenerated carriers. In this study, sandwich structure electrodes consisting of conductive single-walled carbon nanotubes (SWCNTs) and nanocrystalline TiO2 films are prepared as photoanodes of dye-sensitized solar cells (DSSCs). Photovoltaic parameters were found with a short-circuit photocurrent density (Jsc) of 3.42 mA cm-2, an open-circuit photovoltage (Voc) of 0.02 V, a fill factor (FF) of 0.25, and an overall efficiency


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(η) of 0.93%. The improved photoelectrical performance was attributed to the effective separation of photoinduced electrons and holes and the rapid transportation of photogenerated electrons of SWCNT. This sandwich structure electrode represents a promising approach for further improving the efficiency in DSSCs.

Keywords: Dye-sensitized solar cells, Photoanodes, Single-walled carbon nanotubes

Abstract:0093

Performance Evaluation of Solar Cooker with Thermoelectric Generator and Phase Change Materials

Eswaramoothy MuthusamyDepartment of Mechanical Engineering, Vimal Jyothi Engineering College, Chemperi, Kannur-Dist.,

670632, Kerala, INDIA

This research paper communicates the technical study of solar cooker, which consists of thermoelectric generator and phase change materials to generate heat and power to meet the isolated house energy demands. The energy conversion efficiency box type solar cooker was limited to 20% and it thermal performance can be improved to 5% by adding planer concentrator to increase the solar flux falling on the receiver plate, the cooking pot is kept on receiver plate and its uncovered portion is attached by thermoelectric generator with phase change material. The unused heat in receiver plate is transmitted to hot side of thermoelectric generator and rejected heat is stored in phase change materials at minimum constant temperature, the temperature difference is generates electricity by Seebeck Effect. The energy stored in phase change materials is drive the thermoelectric generator during non-availability of solar radiation to generate electricity with ambient temperature change. The standard energy balance equations for individual systems are developed and standard parameters are selected to evaluate its technical study for given design parameters and different operating conditions at Chemperi, Kerala, India. The result shows that the proposed system shows better economic and technical viability to install at insolated rural places where cooking fuels and conventional grid are not reliable.

Keywords: Solar cooker, thermoelectric generator, phase change materials, overall efficiency, combined heat and power


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Abstract:0094

Technical Study of Thermoelectric Generator driven by V-Trough Solar Concentrator (VTSC)

Eswaramoothy MuthusamyDepartment of Mechanical Engineering, Vimal Jyothi Engineering College, Chemperi, Kannur-Dist, Kerala,

India

The parabolic trough and dish type solar concentrator to continuously tracking to capture the concentrated solar radiation and needs additional tracking device and electricity. V trough collector is proposed to derive thermoelectric generator to generate electricity effectively due to its operating temperature. In this paper, Performance analysis of Thermoelectric Generator driven by V-Trough Solar Concentrator (VTSC) is presented. The energy balance equations for receiver of V trough collector, thermoelectric generator with phase change materials are developed and standard operating conditions are selected. The variation of solar radiation and ambient conditions in a year are considered and evaluated for annual performance of the system. The result shows the better thermal and electrical performance is obtained and the proposed system will meet the isolated rural house energy demand.

Keywords: V- Trough Solar Concentrator, Thermoelectric Generator, Phase Change Materials, Thermal and Electrical Performance

Abstract:0095

Synthesis, Characterization and Photocatalytic Activity of Nanostructured Copper (II) Oxide of Different Morphologies

Aderemi Babatunde Alabi1, Nicola Coppede2, Marco Vilani2, Davide Calestani2, Andrea Zappetini2, Olayinka Ajibola Babalola1, Iannotta Salvatore2

1University of Ilorin, Ilorin, Nigeria2CNR-Institute of Materials for Electronics and Magnetism (IMEM) Parma, Italy

Nanostructured copper (II) oxide of different forms namely particles, thin film and sheet have been successfully prepared using simple wet chemical method at both high and low temperatures.

The structure and morphology of the materials were examined by X-ray diffraction and scanning electron microscopy. It was revealed that different morphologies were obtained and the material are crystalline and they all corresponds to monoclinic phase of the crystal lattice. The copper (II) oxide thin film shows a strong absorbing property of the visible light and with an estimated direct transition bandgap of 1.54 eV.

The average grain size of the film is 24.72 nm, while that of the particle and nanosheet are 25.79 nm and 13.8 nm respectively. Photocatalytic degradation of methylene blue was demonstrated with photodegradation efficiency of copper (II) oxide nanoparticle to be 45.12%, while that of the nanosheet is 27%. The different in the efficiency is attributed to the surface area of exposure to the organic dye, determined by their morphologies.

Keywords: Crystalline, Morphology, Grain size, Photocatalysis and Band Gap


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Absorption Spectrum

Absorption Spectrum of CuO Nanostructured film

Photocatalytic Effect of CuO nanoparticles

Photocatalytic effect in degradation of Methylene blue with CuO nanoparticles

Photocatalytic Effect of CuO nanosheets

Photocatalytic degradation of Methylene blue with CuO Nanosheets

SEM image of CuO Nanoparticles

SEM image of the CuO Nanoparticle showing the morphology of the crystaline material

SEM image of CuO Nanosheets

SEM image showing the morphology of the CuO nanosheets synthesized at low temperature

SEM image of CuO Thin Film

SEM of CuO Thin Film showing the morphology (Size and shape of the grains).

Tauc’s Plot for bandgap determination

Tauc’s plot from which the direct bandgap of the material was extrapolated.


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XRD Pattern of CuO Nanoparticles

XRD pattern of the CuO nanoparticle showing the angle of diffraction.

XRD Pattern of CuO Nanosheets

XRD Pattern of CuO nanosheets showing the angle of diffraction of the material

XRD Pattern of CuO Thin Film

XRD Pattern of CuO Thin Film showing the angle of diffraction


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Abstract:0098

Experimental Analysis of different absorber plates on performance of Double slope Solar Still

Ravishankar Sathyamurthy1, Hyacinth J Kennady1, Nagarajan P.k.2, Vijayakumar Dharmaraj3, Sathishkhanna P.4

1Department of Mechanical Engineering, Hindustan Institute of Technology and Science, Chennai2Department of Mechanical Engineering, S.a.engineering College, Chennai


4Department of Electrical And Electronics Engineering, Vivekanandha Institute of Technology And Science, Namakal

In this study, an attempt has been made to see the effect of different absorber materials on the yield of the distillate. The experimental setup is fabricated in GI sheet. The top cover is made of glass of 3mm thickness and to avoid the losses through the solar still it is perfectly sealed. For the experimental investigation three absorber plates Blackened Galvanized iron sheet, Blackened Copper sheet and Blackened Mild Steel sheet were taken. It has been observed that the yield is very low up to noon but increased at after noon. The fresh water production performance of this new still was observed in Hindustan Institute of Technology and Science, Chennai (13°5’ 2” North, 80°16’ 12”East) India. For reducing the cost of solar still, wood chip has used as insulator in the solar still. Few parameters such as glass temperature, water temperature, ambient temperature, air temperature, humid air properties and distillate output with the help of a field experiment and variations are discussed. Solar radiation incident on the solar still is also discussed.

Keywords: Desalination, absorber, distillate output

Abstract:0099

Performance evaluation of triangular pyramid solar still for enhancing productivity of fresh water

Ravishankar Sathyamurthy1, Hyacinth J Kennady1, Nagarajan P.k.2, Vijayakumar Dharmaraj3, Sathishkhanna P.4

1Department of Mechanical Engineering, Hindustan Institute of Technology and Science, Chennai2Department of Mechanical Engineering, S.a.engineering College, Chennai


4Department of Electrical And Electronics Engineering, Vivekanandha Institute of Technology And Science, Namakal

In this study, the effect of geometry on the performance of a tetrahedral solar still was experimentally investigated on Chennai climatic conditions. In this work, a solar still of area 0.95 m2 and a glass cover in a triangular form was designed and fabricated. Environmental parameter includes solar


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intensity, ambient temperatures, and wind speed. Operational parameters are feed water quantity and orientation. Tests were conducted in Hindustan Institute of Technology and Science, Kelambakkam, Chennai, India. The maximum distillate output found was 4.3 lm-2day-1. The results shows that the production of fresh water was increase up to 40% compared to that of other conventional solar stills.

Keywords: Natural convection, solar still, orientation, desalination

Abstract:0100

Silicon Solar Cell under Electromagnetic Waves in Steady State: Electrical Parameters Determination

Issa Zerbo, Martial Zoungrana, Bernard Zouma, Dieudonné Joseph BathieboDepartment of Physics, University of Ouagadougou, Ouagadougou, Burkina Faso

The principal effect that limits solar cell efficiency is the recombination of the photo generated charge carriers before they participate to energy current. This recombination is characterized by electronic (recombination) and electric interdependent parameters that influence the solar cell quality and conversion efficiency. By way of many diagnostic techniques, namely steady state, quasi-steady state, transient and modulation methods both the experimental and theoretical measurements have been developed for determination of single one or several recombination and electrical parameters. Many studies on recombination and electrical parameters of solar cells under constant magnetic field and / or electric field in the bulk due to carrier concentration and under electromagnetic waves have been proposed with one or three dimensional approach: In a previous work, we have presented a one dimensional study in modeling of telecommunication source’s power of radiation influence on silicon solar cell electrical parameters (Rs, Rsh, Jp, Vp, Pp, FF, Rpp) using the I-V and P-V characteristics. Using the I-V and P-V curves we determine the short circuit photocurrent density, the peak photo-current density, the open circuit photo voltage, the peak photo voltage, the peak electric power, the fill factor and the load resistance at the peak power point. In this article, we pursue the previous work introducing the concept of junction recombination velocity initiating the short circuit for determining the value of shunt resistance using its curve versus the junction recombination velocity.

Keywords: 1-Solar cell; 2- Electromagnetic waves; 3- Shunt resistance 4- Series resistance; 5-Peak power, 6- Fill factor, 7- Load resistance.


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Abstract:0104

Triphenylamine-based semiconductors for application in optoelectronic devices

Viktorija Mimaite1, Juozas Vidas Grazulevicius1, Vygintas Jankauskas2

1Department of Organic Technology, Kaunas University of Technology, Kaunas, Lithuania2Department of Solid State Electronics, Vilnius University, Vilnius, Lithuania

Organic electroactive compounds which are able to form stable glasses are used in optoelectronic devices. Triphenylamine derivatives have attractive features due to their high charge carrier mobilities, outstanding thermal stability. Small electroactive molecules are widely studied and used due to their simple synthesis and purification. For dye-sensitized solar cells hole-transporting materials with low ionization potentials are usually required. Structures of the synthesized and characterized triphenylamine-based compounds are shown in Scheme 1. Introduction of methoxy groups into the structure of thriphenylamine-based derivatives 1b,c enables to decrease their ionization potentials approximately by 0.3 eV. Compounds 1a-c form glasses with glass transition temperatures ranging from 74 to 77 ºC and show hole drift mobilities approaching 10-2 cm2/(Vs) at high electric fields.

Glass-forming aromatic hydrazones can be regarded as promising materials for the application in dye-sensitized solar cells. Dye-sensitized solar cell was fabricated with melt processed hydrazone 2 as hole conductor. A solid state solar cell with power conversion efficiency of 0.075 % at 1 sun was obtained. The ionization potentials values of the amorphous films of hydrazones 2 and 3a,b are comparable (5.22 eV-5.29 eV). Compound 3b having three hydrazine moieties showed better charge-transporting properties than hydrazones 2 and 3a with one hydrazine substituent. The possibility of self-polymerization of triphenylamine-based monomers 3a,b was demonstrated. The monomer 3b can be converted into insoluble network.

Keywords: Hydrazone, Triphenylamine, Charge mobility, Solar cell

Scheme 1. Chemical structures of synthesized triphenylamine-based compounds


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Abstract:0105

Ability Of Solar Energy Usage In Rural Communities

Abedalrzaq Suleman Alshqirate1, Mahmoud Ahmmad Hammad2, Alaa Mohammad Al Qteimat3

1Department of Basic and Applied Sciences, Alshoubak University College, Al-Blqa’ Applied University, Al-Salt, Jordan

2Mechanical Engineering Department, University of Jordan, Amman, Jordan3Al-Tafeeleh Technical University, Al-Tafeeleh, Jordan

The fossil fuel costs were led the world to use the free and naturally available energy from the sun to produce electric power A computer simulation study was developed to conclude a solar thermal power using a parabolic solar concentrator. The Euro Trough (ET) Concentrator was used as case study with different working fluids which were: Pressurized water, Boiling water and Oil (Therminol-VP1).

A parabolic trough technology is consists of a concentrator collector field which converts solar irradiation into thermal energy which will be used as input for a Rankine power cycle.

Jordan is one of countries that suffers a scarce of energy resources, so using of renewable energy is gained momentum of the government decision makers. The distribution of direct solar irradiance at different days around the year was calculate and exhibited for Ma’an city (A small town at the south of Jordan) as a case study. A comparison between simulated results and that found in literature were carried out with good conformity. It was found that using water (pressurized or boiling) in the receiver tube is better than the Therminol-VP1 oil. And the pressurized water has the highest value of efficiency compared to the boiling water and Therminol-VP1 oil.

Keywords: computer simulation, solar thermal energy, trough solar concentrator

Abstract:0109

Effect of solution concentration and substrate nature on Poly(3-hexylthiophene) thin layers

Naffouti Wafa1, Mehdi Ahmed2, Ben Nasr Tarek1, Kamoun Turki Najoua1

1Faculty of Sciences of Tunis2University of Montpellier 2

Poly (P3HT) thin films have been synthesized on a glass and SnO2:f substrates using a spin coating method. Atomic force microscopy, spectrophotometry and spectrofluorimetry techniques are used to examine the effect of the experimental conditions on the morphological and optical properties. Films grown on SnO2 substrate were relatively uniform with an average surface roughness of about 14.1 nm. A band gap energy of 2.3 eV was obtained from T (λ) and R(λ) measurements, value close to the theoretical optimum 2 eV [1] indicating that P3HT compound is a suitable compound for solar cell applications. Photoluminescence measurements (PL) showed an emission peak at 530 nm assigned to π - π * transition and reduction of constraint in the case of P3HT/SnO2:F.

Keywords: Solar Cells, Organic thin films, Poly(3-hexylthiophene)


152

Abstract:0110

Annealing effect on the physical properties of the iron doped indium oxide thin films prepared by spray pyrolysis

Beji Nasreddine1, Ajili Mejda1, Guasch Cathy2, Kamoun Turki Najoua1

1Faculté des sciences de Tunis2Institut Electronique du Sud, Université de Montpellier II

Iron-doped indium oxide (In2O3:Fe) thin films were prepared on glass substrates by spray pyrolysis system. The spray solution prepared from indium chloride (InCl3) dissolved in bidistilled water and FeCl2 was added into the solution for iron doping. The atomic percentages of dopant in In2O3-based solution were y = [Fe2+]/[In3+] = 0, 2, 4 and 6%. A best cristallinity was obtained for y equal to 6%. For this value of y thin films were heated in nitrogen. The annealed temperature (Tr) was varying from 200 to 400oC by a step of 100°C and the annealed time was fixed at 45 min. The structural, electrical and optical properties of annealed 6 at.% iron doped In2O3 films, were investigated. X-ray diffraction spectra revealed the presence of cubic structure with (400) preferential orientation. The optical transmittance of In2O3 thin films is high in the visible range (in the order of 82%) and the best transmittance is obtained for Tr equal to 200°C. The electrical properties of 6 at.% iron doped In2O3 films, which corresponds to the best cristallinity, were investigated. It was found that the lowest resistivity (27x10-4Ω.cm) was obtained at the annealing temperature of 300°C. However, before annealing the resistivity was in the order of 5829x10-4 Ω.cm. The lowest resistivity and the highest optical transmittance in the visible range will be two favorable conditions to use this material as transparent conducting oxide (TCO) or as optical window in the photovoltaic devices.

Keywords: Thin films, indium oxide, spray pyrolysis, solar cells

Abstract:0114

Computational Screening of Perovskites for One- and Two-photon Water Splitting

Ivano Eligio Castelli, Kristian Sommer Thygesen, Karsten Wedel JacobsenCenter for Atomic-scale Materials Design, Department of Physics, Technical University of Denmark, Kgs.

Lyngby, Denmark

The development of sustainable energy forms is one of the most important problems of our time because of the ever increasing energy consumption together with the CO2 related climate problems. The conversion of solar light into electrons and holes and the subsequent electrolysis of water to hydrogen and oxygen is one of the possible ways to address the world’s pressing energy supply and storage problem. The properties determining the usefulness of a material to be used as light harvester in a photoelectrochemical cell include (i) a band gap in the visible range with band edges well positioned with respect to the redox levels of water, (ii) good mobility allowing electrons and holes to reach the surface before recombining, (iii) chemical/structural stability under irradiation, and (iv) low cost and nontoxicity. We have performed a computational screening for new materials with focus on one- and


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two-photon water splitting [1,2] using a recently implemented DFT-functional, called GLLB. We find 20 and 12 promising materials for visible light harvesting in the one-and two-photon schemes in the space of 20000 cubic perovskites. In addition, we have applied the screening procedure to the layered perovskite structure, with the focus on how to change the thickness of the layers to tune the bandgap. We also perform a screening for experimentally known materials to use in combination with silicon in a tandem photovoltaic cell.

References [1] Energy Environ. Sci., 5, 5814 (2012). [2] Energy Environ. Sci., 5, 9034 (2012).

Keywords: DFT, computational screening, photoelectrochemical cell, perovskites, semiconductors

Candidates

Materials identified as candidates for the photocatalytic water splitting device. The calculated band edges are in black for the direct and in red for the indirect gap. The levels for hydrogen and oxygen evolution are also included.

Abstract:0115

Organic charge-transporting molecular materials for photovoltaic applications

Juozas Vidas GrazuleviciusDepartment of Organic Technology, Kaunas University of Technology, Kaunas, Lithuania

We synthesized glass-forming hole transporting materials based on carbazole substituted with one or two bis-(4-methoxy-phenyl)-amino groups at C-3 and/or C-6 position of the carbazolyl group for the application in solid-state DSSC. We demonstrated the similar photovoltaic performances of the di-substituted carbazole derivative compared to the reference hole transporter material spiro-OMeTAD. Power conversion efficiency of 3.44% was achieved with 3,6-di(4,40-dimethoxydiphenylaminyl)- 9-phenylcarbazole with a Jsc of 9.47 mA cm-2.

Star shape carbazole trimers with the properties of molecular glasses were synthesized and tested in solid-state DSSC. Their optical gaps (2.76 eV) are high enough to avoid the screen effect with the used indoline sensitizer (D102). Solid-state dye sensitized solar cell ITO/TiO2/D102/T4MPCA/Au was realized and a power conversion efficiency of 2.23 % with Jsc of 8.85 mA cm-2 was achieved under standard AM 1.5 simulated solar irradiation.

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Glass-forming aromatic hydrazones can be also regarded as promising materials for the application in dye-sensitized solar cells. Dye-sensitized solar cell was fabricated with melt processed hydrazone as hole conductor. A solid state solar cell with power conversion efficiency of 0.075 % at 1 sun was obtained.

Perylene bisimides containing carbazolyl and triphenylamino electron-donor groups in the bay region can be of interest for the application in organic solar cells. The materials wide absorption window extending to near infrared region of the spectrum and demonstrate efficient photoinduced intramolecular electron transfer. Complementary ambipolar charge transport was observed in differently linked carbazolyl substituted perylene bisimides while the triphenylamino substituted material exhibited electron drift mobility (>10-3 cm2V-1cm-1) under ambient conditions.

Keywords: Organic semiconductor, molecular glass, solar cell

Abstract:0117

3D modelling of magnetic effects on silicon solar cell electric parameters: series resistance, shunt resistance and junction

capacity

Zoungrana Martial1, Zerbo Issa1, Zouma Bernard1, Sam Raguilnaba2, Bathiebo Dieudonné Joseph1

1Département de Physique, UFR-SEA, Université de Ouagadougou, Burkina Faso2Département de Physique, Institut des Sciences Exactes et Appliquées, Université Polytechnique de Bobo

Dioulasso, Burkina Faso

The solar cells are submitted to the influences of magnetic fields of various origins and intensities: terrestrial magnetic field (5.10-5 T), magnetic component of the electromagnetic wave coming from radios emitters, televisions emitters and telecommunications emitters: (AM antenna, power of radiation: 50W-5kW, B <= 1,29.10-7 T; FM antenna, power of radiation: 500W - 2MW, 4.10-8 T <= B <= 2,58.10-6 T). However, many experimental studies proved magnetic field influences on the solar cells properties: magnetic field influence on carrier’s mobility and photocurrent, magnetic field influence on photovoltage and electron effective mass.

In this work we present a 3D modeling of the magnetic field influence on electrical parameters (Rs, Rsh,C) of a polycrystalline silicon solar cell under intense multispectral illumination. For intense light, the electric field in the base of the solar cell has to be considered; taking into account this electric field and the applied magnetic field in our model lead to two major things: Firstly, new analytical expressions of the continuity equation, the photocurrent and the photovoltage are proposed; secondly an equivalent electrical model of the solar cell under constant magnetic field is proposed and the influence of the magnetic field is pointed out on electrical parameters such as shunt and series resistances and space charge capacitance.

Keywords: Magnetic field, Shunt Resistance, Series Résistance, SCR capacitance


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Abstract:0124

Hybrid TiO2/P3HT photovoltaic devices using a carboxyl Poly(3-hexyl thiophene) derivative

Adriana Pereira Ibaldo1, Roberto Mendonça Faria2, Helmut Neugebauer3, Niyazi Serdar Sariciftci3

1Institute of Physics, University of Brasília – Brazil2Bernhard Gross Polymers Group – Institute of Physics of São Carlos, University of São Paulo – Brazil

3Linzer Institut für Organische Solarzellen – Johannes Kepler Universität, Linz – Austria

We have studied hybrid TiO2/P3HT photovoltaic devices as well as the influence of using the carboxyl P3HT derivative poly[3-(5-carboxypentyl)thiophene-2,5-diyl] (P3HaT) on device performance. The presence of the carboxyl group introduces dipoles pointing from TiO2, shifting the quasi-Fermi levels of oxide, leading to Voc up to 100 mV higher compared to devices containing only P3HT. Furthermore, the effect of thermal annealing on the photovoltaic response for such devices was investigated. We have observed changes of Jsc and FF values, which reflect thermal-induced polymer conformational changes, which are more pronounced for TiO2/P3HT devices, whereas thermal-promoted chemisorption of the carboxyl groups of P3HaT in TiO2/P3HaT:P3HT devices balance these effects. Finally, after 6 months the devices not only still show photovoltaic response, but increased values for Jsc, FF and power conversion efficiency for TiO2/P3HaT:P3HT devices are observed.

Keywords: hybrid photovoltaic devices; titanium dioxide; P3HT

Figure 1

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Abstract:0127

Modelling and analysis of improved solar still integrated with Nano-composite phase change materials

Emil Baby, Muthusamy EswaramoortyDepartment of Mechanical Engineering, Kannur University, Kerala, India

An improved solar still is an urgent need of purified drinking water for rural communities. Thermal conductivity of phase change materials will be improved by mixing phase change materials with nano-materials and its helps to increase the heat release rate during night time for improved productivity. The solar still with designed volume of composite nano-phase change materials will work during 24 hours in day. This paper communicates modeling and analysis of single slope solar still integrated with nano-composite phase change materials. The phase change material is mixer of nano-powder (Al2O3) and paraffin wax. Thermal modeling of solar still with nano composite phase change material is developed based on standard assumptions. A set of design variables and different operating parameters are selected to evaluate the system. It is concluded from the results the proposed system is gives 3% better annual efficiency than paraffin wax alone solar still.

Keywords: Solar still, phase change material (PCM), Aluminum Oxide Nano- material, Nano-composite phase change materials, overall annual efficiency.

Abstract:0128

Effective charge collection from dye-sensitized nanocrystalline TiO2

Masatoshi Yanagida, Mitsunori HondaGlobal Research Center for Environment and Energy based on Nanomaterials Science (GREEN),National

Institute of Materials Science(NIMS)

The nanocrystalline TiO2 film electrode consists of sintering 5-400 nm diameter particles on a transparent conductive oxide (TCO) glass, and has especially been utilized for dye-sensitized solar cells (DSCs). The photoresponse of the short-circuit photocurrent density (JSC) in DSCs is much slower (micro- to milliseconds) than that of classical inorganic semiconductor devices (nano- to picoseconds) because of the small electron diffusion (<10^(–3) cm2 s–1) in the nanocrystalline TiO2 film. During slow transport, an electron in TiO2 can recombine with the oxidized dye on TiO2 or with I3- in the electrolyte. To efficiently collect electrons in the slow electron transport, we investigate three type structures of charge collection electrodes in DSCs are compared. One type structure is a sandwich-type DSC (SW-DSC), in which the TiO2 film is sandwiched between a TCO glass front electron collection electrode and a sputtered Ti back collection electrode. Second is a normal DSC (N-DSC), which has no back electrode. Third is a back contact type DSC (BC-DSC), in which a sputtered Ti back electrode is deposited on a TiO2 film opposite side of the normal glass as an optical window.


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References1, M. Yanagida, Y. Numatab, K. Yoshimatsub, M. Ochiaic, H. Naito, L. Han, Electrochimica Acta 87(2013)309-316.2, M. Yanagida, Y. Numata, K. Yoshimatsu, S. Satoh and L. Han Adv. Nat. Sci.: Nanosci. Nanotechnol. 4 (2013) 015006.

Keywords: dye-sensitized solar cells,nanocrystalline TiO2 film,charge collection

Scheme of DSCs

Abstract:0134

Hydrogen-bonded diketopyrrolopyrrole pigment semiconductors for organic electronics applications

Halime Coskun1, Eric Daniel Glowacki1, Lucia Leonat1, Heinz Langhals2, Marek Grzybowski3, Daniel Gryko3, Niyazi Serdar Sariciftci1

1Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University, Linz, Austria2Department of Chemistry, LMU University of Munich, Germany

3Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland

Diketopyrrolopyrroles (DPPs) have recently gained attention as a building-block for organic semiconducting polymers and small molecules, however they have not been explored in their hydrogen-bonded (H-bonded) pigment forms for such applications. The H-bonded pigment form of DPPs, however, is frequently employed for coloring applications where durability is necessary. Herein we report on the performance of three H-bonded DPP pigments in organic field-effect transistors which show ambipolar carrier mobility in the range 0.01 – 0.2 cm2/Vs. Additionally organic diodes with operational stability in air can be fabricated. Their semiconducting properties are correlated with crystal structure, where an H-bonded crystal lattice supports close and relatively cofacial π-π stacking. We propose that such H-bonded pigment crystal structures can be used as a design technique for effective organic semiconductors.The use of stable organic industrially-established pigments like DPPs enables cheap and mass-producible organic electronics.

Keywords: Diketopyrrolopyrroles, ofets, organic electronics, organic semiconductor, pigments,


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Abstract:0135

Synthesis and Physical Properties of an Anthracene-Containing PPE-PPV

Sameh Boudiba1, Cristophe Ulbricht2, Jacek Gasiorowski2, Reghu Menon3, Sabrina Bouguessa1, Abdelkarim Gouasmia1, Louiza Boudiba1, Niyazi Serdar Sariciftci2,

Daniel A.m. Egbe2

1Laboratory of Organic Materials And Heterochemistry, University Of Tebessa, Algeria2Linz Institute for Organic Solar Cells, Physical Chemistry, Johannes Kepler University, Linz Austria

3Department of Physics, Indian Institute Of Science, Bangalore 560012, India

In recent years many industrial and academic research laboratories have focused on the photo physical proprieties of soluble π-conjugated polymers.[1] Their ease of processability and their tunable electronic and optical properties make them attractive candidates for advanced materials in the field of organic electronics and photonics.

Anthracene-containing conjugated polymers have stirred up a great deal of attention in the past two decades, due to their academic interest and potential technological applications. In the present contribution we report on the synthesis and characterization of a new anthracene-rich poly(arylene-ethynylene)-alt-poly(arylene vinylene) bearing 2-ethylhexyloxy side chains (AnE-AnVbb, Scheme 1). In a polycondensation reaction dialdehyde 1[2] and bisphosphonate 2[3] were reacted following the Horner-Wadsworth-Emmons (HWE) olefination mechanism to form the desired conjugated polymer (Scheme 1).

Scheme 1: Synthesis of the anthracene rich polymer AnE-AnVbb

The chemical structure of the new polymer was confirmed by 1H NMR and FTIR spectroscopy. The photophysical behavior in chlorobenzene solution was found to be concentration dependent. A dielectric function was obtained upon spectroscopic ellipsometry (SE) study in thin film. The electrochemical characterization by cyclic voltammetry showed two non reversible oxidation as well as reversible reduction peaks. Furthermore, the chemical doping of AnE-AnVbb in iodine vapor was investigated. Optical characterization using SE as well as ATR-FTIR revealed the existence of four transitions connected with four polaronic absorption existing in the gap. The conductivity of the polymer was found to be below detection limit, however, after doping, an increase up to 0.69 Scm-1was achieved.

Keywords: anthracene, conjugated polymer, synthesis, photophysical properties, doping


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Abstract:0138

Hybrid solar cells based on ternary CuPc:P3HT:PCBM Bulk heterojunction

Derouiche Hassen, Abdelatif Belhadj MohamedLaboratory of Photovoltaic, Tunisia

Hybrid (organic–inorganic) solar cells based on ternary CuPc:P3HT:PCBM bulk hetrojunction, were fabricated and tested using a photo-anode layer of polyaniline (PANI)-poly(vinylidene difluoride) (PVDF)/ITO and a photo-cathode of nanostructured TiO2/Al. The effect of CuPc doping of P3HT: PCBM composite on the performance of the solar cells was explored and the cells were characterized by current voltage (I-V) measurements under a solar simulator generating AM1.5 light (1000 W/m2) irradiance. It was found that solar cells containing CuPc is likely to improve open-circuit voltage VOC and the fill factor FF in a way superior to that containing only P3HT:PCBM as photo-active layer.

Keywords: Hybrid solar cells, Ternary composites, bulk heterojunction

Abstract:0140

Atmospheric Air Plasma Modification and Thin Film Deposition on Polyimide Substrates for Flexible Thin Film Solar Cell

Applications

Esma Uğur, Erkan Aydın, Nurdan Demirci SankırDepartment of Materials Science and Nanotechnology, TOBB University of Economics and Technology,

Ankara, Turkey

Flexible materials such as polymers and metal foils have been gaining more attention in the thin film solar cell area. The lightweight and mechanical robustness of these materials made it possible to use roll-to-roll manufacturing and adapt the final device onto non-smooth surfaces. Among the polymeric substrates polyimide have been extensively used in photovoltaic and electronic applications due to its very high chemical and thermal stability. However, surface properties of the polyimide must be improved in order to increase the adhesion of the metal back contact and the other layers deposited onto this contact. In this study, atmospheric air plasma has been used to modify polyimide surface. This method is very easy to apply and cost effective. Surface energy of the samples treated for various plasma time and substrate-to-head distance has been determined from the contact angle measurements. In order to determine the applicability of this modification technique to the thin film solar cell area, molybdenum (Mo) thin films have been deposited onto plasma treated polyimide. After that process, different absorber layers such as copper gallium indium sulfide and copper sulfide have been deposited on the Mo thin film. It has been determined that the atmospheric air plasma dramatically affected the electrical and structural properties of the Mo films. Hence, the quality of the absorber layer deposited on Mo film has been improved via plasma treatment.


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Keywords: Flexible solar cell, polyimide, atmospheric air plasma

Air plasma of polyimide and contact angle pictures

Abstract:0143

Numerical study of the thermal performances of a PCM-AIR Heat echanger

Imen Jmal, Mohamed Bouaziz, Mounir BaccarNational Engineering School of Sfax

Thermal energy storage plays a significant role in the solar energy conservation in order to expand its use over time. To exploit solar energy continuously, we require a storage system of solar energy. Phase Change Material (PCM) is used in these systems in order to store heat. Latent heat storage in a PCM is very interesting because of its high-energy storage density and isothermal behavior during the phase change process. Hence, heat accumulated during sunshine period, can be restituted to be used for air conditioning purposes in buildings.

In this perspective, we propose in this work a numerical study based on an enthalpy formulation. The current study numerically investigates the melting and the solidification of a PCM in a heat exchanger with and without fins. This numerical approach gives simultaneously the temperature distributions in the PCM storage system, temporal propagation of the solidification front during the solidification of the PCM when it is exposed to a cold air flow. Also, we give in this study the transient evolution of the air temperature profile.

Keywords: PCM, solidification, heat exchanger, fins, numerical Study.


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Abstract:0152

Hybrid Solar Cells Employing Cu2S Thin Films

Hasan Yüksel Güney1, Gülbeden Çakmak1, Süreyya Aydın Yüksel2, Serap Güneş2

1Department of Physics, Kocaeli University, 41380 Kocaeli, Turkey.2Department of Physics, Yildiz Technical University, 34210, Esenler/Istanbul, Turkey.

Cu2S thin films were used as hole collection layer in hybrid solar cells. The devices were fabricated in the form of ITO/Cu2S/P3HT:PCBM/Al. Thin films of Cu2S were deposited using spray pyrolysis technique at substrate temperature of 300oC±5. We achieved an open circuit voltage (Voc) of 360 mV and a short circuit current density (Jsc) of 2.67 mA/cm2, leading to a power conversion efficiency of (PCE) 0.24 %.

This study was supported by the Research Found of the Kocaeli University (Project number: 2011-61).

Keywords: Cu2S, hybrid solar cell, spray pyrolysis.

Abstract:0153

Characterization of sol-gel grown Cu2ZnSnS4 thin films

Süleyman Kahraman, Samet Çetinkaya, Hacı Ali Çetinkara, Hüsnü Salih GüderDepartment of Physics, Mustafa Kemal University, Hatay, Turkey

As a promising and alternative solar absorber material, the copper-zinc-tin-sulfide compound (Cu2ZnSnS4) has been drawing attention in recent years for the production of cheap thin-film solar cells owing to the high natural abundance and non-toxicity of all the constituents, a tunable direct-band-gap energy and a large optical absorption coefficient. In addition, to overcome the problem of expensive vacuum-based methods, solution-based approaches are being developed for Cu2ZnSnS4 deposition. In this study, we have produced Cu2ZnSnS4 thin films via the sol-gel technique and subsequent sulfurization. The effects of the sulfurization temperature on the structural, morphological, compositional and optical properties of the films were investigated. X-ray diffraction and Raman spectroscopy analyses confirmed the formation of phase-pure CZTS films. The crystallinity of the films increased with an increasing sulfurization temperature. From the surface images and the results of the composition analysis, it was found that the films are uniform, composed of homogenously distributed grains and have compositions with Cu deficit. The values of the optical absorption coefficients for the films were found to be 104 cm-1 based on absorbance spectroscopy. The optical band-gap values were estimated between to be between 1.32 and 2.27 eV depending on the sulfurization temperature.

Keywords: Cu2ZnSnS4, absorber, thin film, XRD, Raman


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Fig. 1

XRD patterns of the CZTS samples sulfurized at a) 200, 300, 400 and 500oC, and b) 700oC.

Fig. 2

Raman spectroscopy analyses of the samples.

Abstract:0154

Visible light-driven water splitting at hybrid photoanodes

Michal Bledowski, Lidong Wang, Radim BeranekRuhr University Bochum

The development of photochemical systems capable of mimicking the natural photosynthesis has attracted significant interest motivated by the need to secure the future supply of clean and sustainable energy. One of the most attractive approaches is solar-driven splitting of water into hydrogen and oxygen. Due to the complex chemistry involved in four-electron oxidation of water to dioxygen, the major challenge in photoelectrochemical water splitting is the development of cheap, efficient and stable photoanodes.

Our recent work has involved the development of a novel class of photoanodes based on visible-light photoactive inorganic/organic hybrid materials – nanocrystalline TiO2 modified at the surface with


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polyheptazine. The optical absorption edge of the TiO2-polyheptazine hybrids is red-shifted into the visible as compared to the bandgaps of both of the single components, which is due to the formation of an interfacial charge-transfer complex between polyheptazine (donor) and TiO2 (acceptor). In other words, the direct optical charge transfer leads to generation of electrons with a relatively negative potential in the conduction band of TiO2, while the holes photogenerated in the surface polyheptazine layer can drive water photooxidation, as evidenced by visible light-driven evolution of dioxygen on hybrid electrodes modified with IrOx or CoOx nanoparticles acting as oxygen evolution co-catalysts. We have found that particularly the photoelectrochemical in-situ deposition of metal oxide co-catalysts is highly beneficial in terms of establishing a good coupling between the absorber and the co-catalyst. Our current attempts at improving the efficiency of kinetic charge separation in such hybrid photoanodes will be discussed.

Keywords: water splitting, photooxidation, organic–inorganic hybrid composites

Abstract:0156

Analysis of Energy Conversion Performance of Photovoltaic/Thermal (PV/T) Collector and Photovoltaic (PV) Module

Halil İbrahim Dağ1, Günnur Koçar2, Ömer Faruk Yüksel3

1Solimpeks Solar Energy Corp., Fevzi Çakmak Mah., 10753 sk., No.3 Karatay-Konya, Turkey2Solar Energy Institute, Ege University, 35100 Bornova-Izmir, Turkey

3Department of Physics, Faculty of Science, Selçuk University, 42075 Konya, Turkey

In this study, the productions of the photovoltaic module and also the water-type photovoltaic/thermal (PV/T) collector are realized and their conversion performance analyses are performed. Identical single crystal silicon PV cells are used in the productions of both PV/T collector and also PV module. In the production of PV/T collector, the thermal part is integrated with the PV cells by using the lamination technique. The energy conversion performances of PV/T collector and PV module are measured under the same solar conditions. The electric and thermal energy conversion performance of PV/T collector, and the electric conversion performance of PV module are measured as a function of time. In addition, the solar radiation values are simultaneously recorded. Finally, the energy conversion analyses of them are made comparatively.

Keywords: PV/T hybrid collector, PV/T performance, photovoltaic.


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Abstract:0161

Effect of Impurities in Semiconducting Polymers on Solar Cell Performance

Özlem Usluer1,3, Mamatimin Abbas2, Eric Cloutet1, Cyril Brochon1, Guillaume Wantz2, Laurence Vıgnau2, Lionel Hırsch2, Georges Hadziioannou1

1Université Bordeaux 1, Laboratoire de Chimie des Polymères Organiques (LCPO), CNRS (UMR 5629), ENSCPB,16 avenue Pey Berland, 33607 Pessac Cedex, France

2Université Bordeaux 1, Laboratoire de l’Intégration du Matériau au Système (IMS), CNRS (UMR 5218), Site ENSCPB,16 avenue Pey Berland, 33607 Pessac Cedex, France

3Department of Chemistry, Mugla Sitki Kocman University, kotekli, Mugla 48000, Turkey

Conjugated polymers have been extensively investigated over the last few decades due to their potential applications in organic electronics such as organic photovoltaic cells (OPVs), organic light emitting diodes (OLEDs), and organic field-effect transistors (OFETs). During the synthesis of the conjugated polymers, transition metallic-based materials is often used as catalysts. Residual catalysts and other organic or inorganic impurities present in the conductive polymers may act as charge traps or photoquenchers affecting strongly their intrinsic properties consequently reducing the performance of the optoelectronic devices.

In this work, we aim to investigate methods to remove impurities in polymers and compare the device performances in OPVs to non-purified one.

Here, as a preliminary investigation, high molecular weight semi-conducting polymers were synthesized by the Grignard metathesis method (i.e. using a Ni-based catalysis) and Suzuki cross-coupling (i.e. using a Pd-based catalysis) polymerizations processes respectively [1,2]. The polymers were purified by different purification

METHODS: precipitation, complexation Soxhlet extraction respectively [3,4]. After each purification process, a fraction was analyzed to determine its composition in impurities by various techniques such as SEC, 1H NMR, ICP-MS, RBS and PIXE. In addition, the effect of impurities on electro-optical properties of the studied semi-conducting polymers was carried out via the fabrication of organic bulk heterojunction solar Cells (OSCs).

References:

[1] Iovu,M.C. et al. Polymer 2005, 46, 8582-8586.[2] Brabec et al., Adv. Mater. 2006, 18, 2884-2889.[3] Xiao, S. S., Qiu, C., Qiu, C. X., United States Patent Application Publication, US20040254336A1.[4] McCullough, R. D., Iovu,M.C., WO 2008/063731 A2.

Keywords: Conducting polymer, organic Solar Cell, impurities


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Abstract:0162

Light energy harvesting with nano-dipoles

Michele Garbugli1, Matteo Porro2, Vittoria Roiati2, Aurora Rizzo3, Giuseppe Gigli4, Annamaria Petrozza2, Guglielmo Lanzani2

1Dept. of Physics, Politecnico di Milano, p.zza Leonardo da Vinci 32, 20133 Milano, Italy2Center for Nano Science and Technology@Polimi, Istituto Italiano di Tecnologia, via G. Pascoli 70/3, 20133 Milano, Italy.

3National Nanotechnology Laboratory (NNL), Istituto Nanoscienze- CNR, c/o Distretto Tecnologico, via per Arnesano 16, I-73100 Lecce, Italy

4Center for Bio-Molecular Nanotechnologies (CBN) of IIT@NNL-UniLe- Lecce, via Barsanti, Arnesano, 73010 Lecce, Italy

We propose a new approach for converting light energy into electrical energy, based on the photogeneration of nano-dipoles at the interface between organic semiconductors.

Organic photovoltaics in third generation solar cells exploits electron donor–acceptor (D–A) extended interfaces in the so-called bulk heterojunctions, whose working principle and major issues are well known. We show that the ability of the D–A pair to efficiently transfer an electron upon light absorption can be exploited in a different way if the D–A pairs are organized in ordered arrays.

In our flat evaporated interface, a macroscopic polarization is induced by the coherent sum of these oriented nano-dipoles, once light is shine from the acceptor side.

The polarized medium, sandwiched between two capacitor plates, will induce a current in the external circuit that can be used to generate power through a load resistance, as happens in pyroelectric detectors.

In this way one can convert light energy into electrical energy without generating a current through the active layer. Such an approach gets rid of the transport issue in the device engineering, whilst internal quantum efficiency remains high.

We provide a proof of concept and we discuss the ideal limit of the device based on numerical simulations.

Simulations show that the proposed device can be an appealing opportunity with giant conversion efficiency provided some technological issues are overcome.

Photo-physical analysis (photoinduced absorption spectroscopy and electroabsorption) have been performed to investigate further the working device.

Keywords: Organic photovoltaics, interface dipoles, light harvesting

Equivalent electrical circuit


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Flowchart

Proof of concept and fit

Schematic of working principle

Schematic of the working principle of the device based on photogeneration of nano dipoles


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Abstract:0163

Naphthalimide-functionalized fluorene and carbazole derivatives

Dalius Gudeika1, Juozas Vidas Grazulevicius1, Vygintas Jankauskas2


Two of the most exploited aromatic units constituting the multichromophoric systems are carbazole and fluorene, which, in fact, by proper substitution are capable of delivering multifunctional properties. For instance, carbazoles, known as classic hole transporters, are also utilized as light-emitting materials [1]. Meanwhile, fluorenes, which are famous for high fluorescence efficiency, easy wavelength-tunability, and therefore, employed as an active media in OLEDs [2] and organic lasers [3] have also been employed in photovoltaic devices [4]. In this work, a series of fluorene and carbazole derivatives substituted with naphthalimide at 2- and 2,7-positions were synthesized (Fig.1). The structures of all the synthesized compounds were proved by methods. The properties of the synthesized materials were investigated by UV and fluorescence spectrometries, thermogravimetry, differential scanning calorimetry, cyclic voltametry, time-offlight technique. 1H NMR, 13C NMR, IR spectroscopy, mass spectrometry and elemental analyses methods. The properties of the synthesized materials were investigated by UV and fluorescence spectrometries, thermogravimetry, differential scanning calorimetry, cyclic voltametry, time-of-flight technique.

References:

[1] Cho, I.; Kim, S. H.; Kim, J. H.; Park, S.; Park, S. Y. J. Mater. Chem. 2012, 22, 123-129.[2] Yap, B. K.; Xia, R.; Campoy-Quiles, M.; Stavrinou, P. N.; Bradley, D. D. C. Nat. Mater. 2008, 7, 376-380.[3] Komino, T.; Nomura, H.; Yahiro, M.; Endo, K.; Adachi, C. J. Phys. Chem. C 2011, 115, 19890-19896.[4] McNeill, C. R.; Halls, J. J. M.; Wilson, R.; Whiting, G. L.; Berkebile, S.; Ramsey, M. G.; Friend, R. H.; Greenham, N. C. Adv. Funct. Mater. 2008, 18, 2309-2321.

Keywords: Naphthalimide, fluorene, carbazole

Fig. 1. The chemical structures of naphthalimide-substituted fluorene (1, 2) and carbazole (3, 4) compounds.


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Abstract:0164

Latitude Based Model for Tilt Angle Optimization for Solar Collectors in Morocco

Driss Lahjouji, Hassane DarhmaouiSchool of Science & Engineering, Al Akhawayn University in Ifrane, Ifrane, Morocco

This paper inspects the different parameters that intervene in the determination of the optimum tilt angle for maximum solar energy collection. It proposes a method for calculating the optimum tilt angle based upon the values of the daily global solar radiation on a horizontal surface. A computer program using the mathematical model to calculate the solar radiation incident on an inclined surface as a function of the tilt angle is implemented. Four years data of daily global solar radiation on a horizontal surface in 28 sites in Morocco is used. The program assumes a due south orientation of the collectors and it determines the optimum tilt angle for maximum solar radiation collection for sites in Morocco. A regression analysis using the results of the computer simulation is conducted to develop a latitude based tilt angle optimization mathematical model for maximum solar radiation collection for the sites. We tested both a linear and a quadratic model (of the form ax²+bx+c) for representing the relationship between the annual optimum tilt angle and site’s latitude. The quadratic model is better; it provides very high prediction accuracy. 99.94% of the variation in the annual optimum tilt angle is explained by the variability in site’s latitude with an average residual angle of only 0.65° for all 28 sites studied. It also gives an average percentage decrease in the annual solar radiation of only 0.0068% when compared with actual optimum tilt angles.

Keywords: Tilt angle optimization, solar radiation, regression analysis, latitude based model

Abstract:0165

Improvements in Photovoltaic module efficiency through transparent layer of Polyacrylamide hydrogel as robust

cooling system

Ehsan Moaseri1, Majid Karimi2, S. Mostafa Nowee1

1Chemical Engineering Department, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran2Chemical Engineering Department, Quchan Institute of Engineering and Technology, Quchan, Iran

Temperature control plays a pivotal role in both short-term and long-term utility of Photovoltaic cells. Elevation of module’s cell temperature leads to decrease in module efficiency and even impacts the life span of the cell. In this study, a robust cooling system has been introduced for Photovoltaic cells through incorporation of a transparent layer of Polyacrylamide hydrogel on the surface module.

A layer of Polyacrylamide hydrogel was located on the surface of module (Figure 1). This polymer is able to absorb water molecules and transfer them throughout the hydrogel layer. Huge amount of water molecules can be stored inside the polymer chains (320 times more than its own weight). Refrigeration of the cell was carried out by reducing the stored heat in the module by evaporation of the water


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molecules cumulated in the polymer chains. The bottom of the hydrogel layer was immersed in a water container to compensate the water evaporation. Also, a storage tank was designed to keep the water container full.

Polyacrylamide hydrogel benefits from excellent optical transparency, high thermal stability and well anti-reflectivity features. These characteristics along with its reasonable cost and good reproducibility make it an ideal choice to be applied as cooling layer on the surface of Photovoltaic cells.

Various characterizations have been implemented to evaluate the efficiency of the proposed cooling system. Results imply that adoption of the proposed cooling system has led to drastic drop in module temperature and consequently notable improvement in the electrical yield of the cell (up to 10%).

Keywords: Photovoltaic cell, Cooling system, Transparent layer, Polyacrylamide hydrogel

Figure (1) Schematic configuration of the proposed cooling system

Schematic configuration of the proposed cooling system

Abstract:0168

In vitro Synthesis of LHCII Proteopolymersomes

Thomas ZapfDepartment of Nanobiotechnology, Laboratory for Synthetic bioarchitectures, University of Natural

Resources and Life Sciences, Vienna, Austria

The process of light harvesting is present in all photosynthesizing organisms ranging from simple Archea to plants. Throughout evolution the core structure and function of the light harvesting complex has remained preserved. Photosynthesis is one of the most important and successful strategies of nature and although there are decades of research on this process uncertainties remain. We present a novel approach to synthesize the light harvesting complex II (LHCII), using a coupled transcription-translation cell-free wheat germ extract system, and integrating it directly into a biomimetic diblock-copolymer membrane system. This serves to enhance its stability outside chloroplast membranes for in vitro studies. Polymeric bilayered vesicles are formed from BD21 in the presence of chlorophyll extract, derived from pea leaves, for chlorophyll incorporation into the membrane. The oriented and direct integration of the LHCII into the polymer vesicles is probed for using Surface Plasmon Resonance, TEM and Western blotting. Imaging of the resulting LHC II proteopolymersomes by TEM is performed in


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order to assess quantity and to analyze integration. The aim of this project is to study LHC integration and reconstitution in polymeric membranes and to open the possibility for technological usage of LHCII.

Keywords: Light harvesting, Photosystem, Polymersomes

Abstract:0171

High voltage flexible dye-sensitized solar cells employing ZnO photoelectrode sensitized with D35 dye in Co redox couple

Tatsuhiro Chiba1, Tsutomu Kitazawa1, Shogo Mori2, Tsukasa Yoshida1

1Reseach Center for Organic Electronics (ROEL), Yamagata University2Materials and Chemical Engineering Course, Faculty of Textile Science and Technology, Shinsyu University

We have been developing flexible dye-sensitized solar cells based on screen printing of ZnO nanoparticles that yields highly conductive, strongly adhesive and stable photoelectrode without applying high temperature sintering. One of the weakness of ZnO solar cells has been their low voltage to limit the efficiency. We have found that adsorption of triphenylamine dye, D35 (Fig. 1), on ZnO results in highly rectifying dye layer to achieve close to 1 V in combination with Co(II/III) redox couple.

The cell employing Co redox exhibits superior performance to those with TPAI and DMPImI, achieving Jsc = 7.04 mA cm-2, Voc = 924 mV, FF = 0.40 and η = 2.61% (Fig. 2). Despite of the high kinetic reversibility of the Co(II/III) redox couple, the dark current in the Co cell is much smaller than those of the iodide cells. A highly compact packing of D35 molecules on ZnO surface is expected to passivate the surface for reduction of Co(III) species so that a high electron concentration, thus a high voltage, is achieved under illumination. Indeed, such a character is not seen for most other organic dye sensitizers showing leaky dark profile and only small voltages. Not only the voltage but also the photocurrent was much higher for the Co cell, achieving a reasonably high IPCE of 70% at the maximum (Fig. 3). The poor FF is obviously the limiting factor for the Co cell, that most likely arise from the limited hole transporting ability of the Co redox.

Keywords: Dye-sensitized solar cell;ZnO;D35 dye;Cobalt redox

Fig.1 Structure of D35 dye


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Fig.2 I-V curves of ZnO/D35 flexible cells with various electrolytes.

Fig.3 Photocurrent action spectra of ZnO/D35 flexible cells with various electrolytes

Abstract:0172

Solution processed charge carrier transport layers and electrodes for polymer solar cells

Jonas Hanisch, Cordula Wessendorf, Jerrit Wagner, Matthias Pysik, Tina Wahl, Erik Ahlswede

Zentrum für Sonnenenergie- und Wasserstoff-Forschung Baden-Württemberg (ZSW), Stuttgart, Germany

Polymer solar cells have attracted much attention in the last years because of the possibility to produce lightweight, flexible, colored, and if desired semitransparent devices. They have the potential to be a cheap alternative compared to the established technologies due to a very small material consumption and the feasibility of coating the layers from solution.

To reach this goal really all layers should be solution-processed. Furthermore all used materials and applied processes must be inexpensive. At the same time a high power conversion efficiency and an adequate stability of the cells is required.


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We investigated various vacuum-free deposited opaque as well as transparent (e.g. Ag nanowires) electrodes. In addition solution-processed charge carrier transport layers for electrons (ETL) and holes (HTL, e.g. MoOx and ITO nanoparticle solutions) are tested in solar cells.

For this purpose we built cells in the more stable inverted structure and in the standard architecture as reference. Thus we could demonstrate the substitution of the layers deposited by vacuum processes with layers coated from solution.

These layers are predominantly deposited by doctor blading to guarantee a transfer of the materials and methods to a large-scale and suitable process for an industrial realization.

Keywords: polymer solar cell, charge carrier transport layer, electrode, solution processed, doctor blading

Abstract:0176

Solar Powered Poultry Egg Incubator with Phase Change Heat Storage Subsystem

Onyekwere Ojike, Wilfred Ifeanyi OkonkwoDepartment of Agricultual Engineering, University of Nigeria, Nsukka, Nigeria

The design, construction and performance evaluation of a solar powered poultry egg incubator with phase change material is presented in this study. The system, which has 50 egg capacity, consists of a double-glazed flat plate solar collector of an area 2.2m2 integrated with a paraffin type phase change material (PCM) energy storage subsystem. The PCM is contained in four equal black rectangular steel boxes each neatly laid side by side so that their top formed absorber plate with a selective surface. Top of the absorber plate serves as an air heater while air flow through the system is by natural convection. The incubator is incorporated with a PV subsystem made of PV module, a deep cycle battery, a charge controller, an electronic temperature regulator, two 15W DC bulbs and a DC motor with air inlet door connected to it. Both the solar collector and the PV subsystem maintained the chamber temperature within the range of between 36oC to 39oC needed for egg incubation. Relative humidity of 50% to 75% is maintained by the use of water trough placed in the chamber. The performance evaluation of the system over an ambient temperature range of between 18–36 °C, and a daily global irradiation range of between 4.9–19.9 MJ m2.involved both physical monitoring of the temperature, the relative humidity of the incubator and the use of fertilized poultry eggs to determine the efficiency of the incubator. Results showed an average egg hatchability of 62.37% using the incubator was obtained.

Keywords: Solar, incubator, design, evaluation


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Abstract:0177

TIO2 Sensibilised oxide by electrodeposited platinium film

Naamoune Farid1, Messali Salima2

.....

Titanium has the ability to cover the surface in an aqueous solution of an oxide layer (TiO2) with semiconducting properties are utilized for the conversion of solar energy. TiO2 oxide in passivating character (gap: 3.2 eV), is surface modified by implanting a thin platinum film. The electrochemical study in voltammetric mode, was able to show the influence of various experimental parameters (nature of the electrolyte concentration, scanning speed and final potential) on the growth of the oxide layer. When the oxide is in depletion regime, the electron transfer across the oxide layer is made by tunneling via intermediate states. The modification of a noble metal oxide significantly improves transfer properties of anodic and cathodic charging. The positive results obtained on the titanium oxide of platinum could be applying photo-conversion.

Keywords: titanium oxide, platinum film, voltamperometric study, charge transfer, gap.

Abstract:0178

Up-conversion photoluminescence in Er3+-doped titania/nanoporous TiO2 bi-layer electrodes for efficiency

enhancement of dye-sensitized solar cells

Hoda Hafez1, Hala Shibl1, Mona Saif2, Rifai Rifai1, Sabry Abdel Mottaleb3

1Nano-Phochem. Lab., Environmental Studies and Research Institute, University of Sadat City, Minoufiya, Egypt

2Faculty of Education, Ain Shams University, Roxy, Masr El-Gedida, Cairo, Egypt.3Nano-Photochemistry and Solarchemistry Lab., Department of Chemistry, Faculty of Science, Ain Shams

University, Abbassia, 11566 Cairo, Egypt

In the present work, a novel approach to extend the spectral response of the dye-sensitized solar cells (DSSCs) has been achieved by spectral modification of the cell absorbance based on the phenomenon of up-conversion (UC). This has been done by applying a bi-layer photoelectrode design from Er3+-doped titania/nanoporous TiO2 thin layers. The nanostructure and morphology of the different x%Er3+-doped TiO2 thin films where, x= 0.00, 0.01, 0.02 and 0.05 mole%, have been prepared and investigated by XRD, SEM, and UV-Vis diffuse reflectance. The visible emission properties of the different Er3+-doped TiO2 thin layers have been examined under different excitation wavelengths in the range of (700-800nm) where, the photoluminescence from intra-4f transitions of erbium ions in TiO2 matrix have been explained.

Bi-layer film electrodes from Er3+-doped titania/nanoporous TiO2 thin layers have been fabricated and applied in DSSCs. The photon-to current conversion efficiencies (η) of the cells based on 0.01, 0.02 and 0.05 mole% Er3+-doped TiO2 thin layers are 4.74%, 5.17 and 4.18%, respectively, which is higher than that of pure TiO2 film electrode (η = 4.17%). A maximum efficiency enhancement of (24%) has


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been achieved by applying 0.02 mole% Er3+-doping. This enhancement has been attributed to the up-conversion photoluminescence characteristics of Er3+ ions.

Keywords: Up-conversion; Photoluminescence; Erbium-doped titanium dioxide; Dye-sensitized solar cells.

Abstract:0180

Environmental Friendly, Low Cost Quasi Solid State Dye Sensitized Solar Cell: Polymer Electrolyte Introduction

Hala Mohamed Shibl1, Hoda Said Hafez1, Rifai Ibrahim Rifai1, M. S. A. Abdel Mottaleb2

1Nano-Environmental Photochemistry Laboratory, Environmental Studies and Research Institute, Minoufiya University, Sadat Branch, Minoufiya, Egypt

2Nano-Photochemistry and Solarchemistry Laboratory, Department of Chemistry, Faculty of Science, Ain Shams University, Abbassia, Cairo, 11566, Egypt

The most efficient DSSCs reported till date contains liquid electrolytes with I-/I3- redox couple. However, the disadvantages of liquid electrolytes lead to reduce the impact of DSSCs. In the present work, the I-/I3- liquid electrolyte was replaced by quasi-solid gel polymer electrolytes (GPEs) using polyethylene glycol (PEG, Mwt=20,000), which are incorporated in small fractions (0, 1, 5, 10,15 and 20% w/v) into the liquid iodine/iodide electrolyte matrix. The roughness and homogeneity of the GPEs on the surface of the TiO2 electrodes was monitored by atomic force microscope (AFM) which indicates the physical cross linking of polymer chains in a gel network. The conductivity (σ) and the thermal stability (TGA) of the GPEs compared with the liquid electrolyte were studied in details.

The photovoltaic characteristics (Voc, Isc, fill factor (FF) and efficiency (η)) of the DSSCs based GPEs were recorded, The results revealed the DSSCs assembled with the gel polymer electrolyte reports a higher short circuit density (JSC) and lower or similar open circuit voltage (VOC) than the cells with liquid electrolyte. The overall light-to-electrical-energy conversion efficiencies (η) of the cells based GPEs showed a relatively higher stability over a period of time compared with those based liquid electrolyte, indicating that the quasi-solid nature of the GPEs may impart flexibility to DSSCs so that some large-scale productions such as roll-to-roll process can be realized.

Keywords: Quasi solid state DSSCs; Gel polymer electrolyte. Polyethylene glycol


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Abstract:0182

On the Development of High Performance Elastomers Seal Systems for Hydrogen Transport and Dispensation

Umut D Cakmak, Zoltan MajorInstitute of Polymer Product Engineering, Johannes Kepler University, Linz, Austria

The well known limitation of fossil fuels requires the adaptation of current energy conversion systems (temperature control, mobility) to this circumstance. Various models describe the exhaustion scenarios with faster or slower prognoses. However, a better estimation of the adaption of the energy conversion technologies can be found in the policy goals for the future such as the EU Roadmap 2050 targets (80% below 1990 levels greenhouse gas emissions). This means in terms of mobility a move from combustion to zero-emission engines, as it has already started with electro vehicles. A promising alternative are hydrogen fuel cells, which would combine the advantages of electro powered cars with low refueling times and the capability to drive extended distances. Fuel cells and hydrogen fuel were addressed in many research activities and practical solutions were presented, in field testing and are already in use. Moreover, the uses of solar energy for the electrolysis of hydrogen from water, which can be converted back to electricity, were also presented. Unfortunately, the rapid gas decompression (see Fig.1) failure of the elastomeric seals especially in the refueling dispenser system of hydrogen remained unaddressed. This phenomenon which occurs under high pressures (700 bar) and high temperature changes was first observed intensively investigated by the Polymer Team (Nishimura) at the Kyushu University in Japan. Based on this severe failure mode of the seals a research project in a European consortium with the collaboration of many research groups was set-up to develop high performance elastomer seals for hydrogen transport and dispensation.

Keywords: Hydrogen Fuel Cell, Elastomeric Sealing, Dispenser, Rapid Gas Decompression

Fig.1

Illustration of the contact state of the tested sealing with the applied pressure including the crucial decompression phase. The pictures on the right show the RGD-failure and the damage.


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Abstract:0185

Bio-inspired Zinc Chlorins for Dye Sensitized Solar Cells*

Kasim Ocakoglu1, Sule Erten Ela2, Khurram Saleem Joya3, Ersan Harputlu1

1Advanced Technology Reseach&Application Center, Mersin University, Ciftlikkoy Campus,TR33343,Yenisehir,Mersin, Turkey.

2Institute of Solar Energy, Ege University, Bornova, Izmir 35100, Turkey.3Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, P.O. Box 9502, 2300 RA, Leiden, The

Netherlands.

Capturing light energy and transforming it efficiently into electricity in a solar cell device offers an attractive solution to the future energy quests triggered with fossil fuel prices and related environmental issues. Dye sensitized solar cells (DSSC) are successful alternatives provide a cheaper mean then traditional semiconductor based PV system. During the developmental journey and technical modification of the DSSC’s, various dye modules have been implemented that were derived from ruthenium polypyridyl complexes. However, ruthenium dyes are expensive and their preparations include lengthy purification steps. In order to bypass the limitations imposed by expensive dyes using rare metals complexes, scientific attention has turned to go for cheaper and easy accessible light-harvesting (LH) molecules. In nature, plants have developed outstanding light-harvesting systems that use supramolecular chlorophyll (Chl) aggregates for efficient light capture and transfer into energy. Using the natural concept, we started getting interest in using BChl based biomimetic dyes to make DSSC. Here we report a DSSC with synthetically modified zinc chlorin (Zn-Chl) dyes to make a cheaper assembly for light conversion into electricity. We have prepared the semi-synthetic Zn-Chls in which the 31-hydroxy group has been substituted by amino group for the attachment with TiO2 matrices. In addition, the density functional theory (DFT) calculations are also used to estimate the photovoltaic properties of Zn-Chl derivatives in the design stage.

* This research has been financially supported by The Scientific and Technological Research Council of Turkey, TUBITAK (Grant: 110M803) in the framework of European Science Foundation (ESF-EUROCORES-EuroSolarFuels-10-FP-006).

Keywords: Dye sensitized solar cell, zinc chlorins, chlorophyll.

A model structure of zinc chlorin (Zn-Chl).


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Abstract:0186

A Unified Study of Recombination in Polymer:Fullerene Solar Cells

Armantas Melianas1, Lars Mattias Andersson1, Yingyot Infahasaeng2, Zheng Tang1, Arkady Yartsev2, Olle Inganäs1, Villy Sundström2

1Biomolecular and Organic Electronics, Department of Physics Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping, Sweden

2Chemical Physics, Lund University, P.O. Box 124, SE-22100 Lund, Sweden

Further material design and device engineering of polymer/fullerene solar cells can benefit greatly from knowledge about the dominant recombination pathways in these materials. Obtaining such information, however, is not always trivial. Since timescales, measurement conditions, and sample geometries tend to differ significantly for different recombination measurement techniques, the conclusions therefrom can vary even for the same material systems.

Here, results from two of the most common and straightforward techniques for recombination studies, pump-probe transient absorption (TA) and extraction of photo-generated carriers by linearly increasing voltage (photo-CELIV) are correlated with each other. We have followed photogenerated charge carrier density over four orders of magnitude in concentration and over six orders of magnitude in time. The recombination kinetics obtained with the two methods are shown to be mutually fully consistent. However, viewed separately the data also illustrate the risk of incomplete or even disagreeing interpretations regarding the underlying recombination mechanism due to differences in the experimentally accessible time range.

Deviations from an ideal bimolecular recombination process are explained with a time dependent charge carrier mobility, the time dependence of which is quite important in the future development of organic solar cells.

Keywords: Organic Photovoltaics (OPVs), Conjugated Polymer, Recombination, Transient Absorption (TA), Photogenerated Charge Extraction (photo-CELIV)

Recombination loss of photogenerated charge carriers

Calculated from the fits of experimental data. Charge separation dynamics are ignored in this figure.


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Abstract:0187

Synthesis and Properties of Indolo[3,2-B]Carbazole-Based Hydrazones for Optoelectronic Devices

Egle Stanislovaityte, Jurate Simokaitiene, Juozas Vidas GrazuleviciusDepartment of Organic Technology, Kaunas University of Technology, Kaunas, Lithuania

Great variety of different compounds were reported during last decades as charge transporting materials for the application in optoelectonic devices. Among the high-performance compounds indolo[3,2-b]carbazole derivatives are among the most popular ones. The large planar and rigid conjugated structures of these derivatives allow efficient charge-injection and transfer. We synthesized indolo[3,2-b]carbazole derivatives containing reactive oxiranyl, vinylbenzyl and vinyloxyethyl groups which can be used for preparation of polymeric or even cross-linked hole-transporting layers by photoinduced or thermal polymerization. To improve the properties of these compounds we derivatized them with hydrazine moieties. Most of the compounds are capable of glass formation, with the glass transition tmeperatures in the range of 18–84 °C. The ionization potential values measured by electron photoemission in air and cyclic voltamperometry methods are close, 4.99–5.18 eV and 4.94–5.00 eV, respectively. Electron affinity values are in the range of -2.28– (-2.21)eV. The hole drift mobilities of amorphous films of compounds established by xerographic time-of-flight technique are 8×10-5-5.5×10-4 cm/Vs at electric field of 6.4•10 5 V/cm.

Keywords: INDOLO[3,2-b]CARBAZOLE, HYDRAZONES, SYNTHESIS, PROPERTIES

Scheme


179

Abstract:0192

Porous Solar Ponds for Seasonal Storage

Mohamed Jomaa SafiIndustrial Department, National Engineering School of Tunis, Tunis, Tunisia

It is well known that the main problem encountered with solar energy is its dispersion in time and space. Indeed, seasonal storage is necessary.

An efficient and friendly solution is that of solar pond. It consists of a pond with three layers stratified in density. The upper layer UCZ collects the solar radiation.. The second intermediate layer NCZ acts as thermal insulator and prevents heat loss so that temperatures ranging from 40°C to 100°C are maintained in the bottom layer LCZ. This natural solution has been reproduced and tested in heating, electricity generation, and desalination by many countries since the fifteenth. Unfortunately, the lifetime of a solar pond doesn’t exceed 10-15 years due to some problems especially the double diffusion movement which appears in the bottom, grows with time, and destroys the stratification. Thus the pond stops storing heat. To overcome this problem we suggested, the use of porous media in the LCZ to inhibit the convective movement. After laboratory experiences, we extended our investigations by testing in field 2 ponds of 4m2 each:

- The first one is a standard gradient solar pond,

- and, the second one includes porous media in the LCZ.

The results showed that temperature fluctuations encountered in standard ponds vanished thanks to the presence of porous media and the behaviour of the pond becomes more stable extending its lifetime.

Keywords: solar pond, storage, double diffusion, porous media

Abstract:0193

Effect of thermal treatment on nc-SiH thin films growing by PECVD at different substrate temperature

Sana Ben Amor, Wissem Dimassi, Seif El Whibi, Hatem EzzaouiaPhotovoltaic Laboratory Research and Technology Centre of Energy, Borj-Cedria, Tunisia

Nanocrystalline hydrogenated silicon films (nc-SiH) films were deposited by plasma enhanced chemical vapor deposition (PECVD) under different substrate temperature. After deposition, these films sustained a thermal treatment at 850°c realized in an infrared furnace under Argon for 3 min. The correlation between the characteristics of Si-Hn bonds before and after thermal treatment was investigated. Furthermore, the deposition rate and the carrier life time were also studied. Finally, a correlation between structural and optical properties has been found.

Keywords: Nanocrystalline hydrogenated silicon, PECVD, Substrate temperature, Thermal treatment


180

Abstract:0195

Preparation and structural characterization of nano-sized structure Zn0.8Cd0.2S prepared by simple dip coating

Naglaa Roushdy Mohamed Ahmed1, Alaa Farag2, Mohamed Abdel Rafea1, Osama El Shazly3, Wahidy Wahidy3

1Electronic Materials Department, Advanced Technology and New Material institute, City for Scientific Research and Technology Applications, New Borg El Arab City, Alexandria, Egypt.

2Thin Film Laboratory, Physics Department, Faculty of Education, Ain Shams University, Heliopolis, Roxy, Cairo 11757, Egypt.

3Physics Department, Faculty of Science, Alexandria University, Egypt.

In this work, nanocrystalline powder of Zn0.8Cd0.2S was synthesized using dip coating technique. Thin films of Zn0.8Cd0.2S were prepared by the same technique onto glass substrates. The composition analysis was made by the energy dispersive X-ray analysis (EDX). X-ray analysis of the Zn0.8Cd0.2S was performed to investigate the crystalline structure and determine the characteristic structural parameters such as the mean crystallite size (D), the internal lattice strain (ε), the dislocation density (), the lattice deformation stress () [?]and the lattice strain energy density (u) using the three Williamson-Hall (W-H) models. The surface morphology of the prepared Zn0.7Cd0.3S was studied using the scanning electron microscopy (SEM). The high resolution transmission electron microscope (HRTEM) was used to check the crystallinity of the prepared samples. The thickness of Zn0.8Cd0.2S film measured by the SEM cross sectional image.

Keywords: XRD parameters, (W-H) models, SEM, HRTEM

Abstract:0196]

Down-converting lanthanide doped TiO2 photoelectrodes for efficiency enhancement of dye-sensitized solar cells

H. Hafez1, M. Saif2, M. S.a. Abdel Mottaleb3

1Environmental Studies and Research Institute (ESRI), Minoufiya University, Sadat Branch, Sadat City, Egypt

2Department of Chemistry, Faculty of Education, Ain Shams University, Cairo, Egypt3Nano-Photochemistry and Solarchemistry Lab., Department of Chemistry, Faculty of Science, Ain Shams

University, Abbassia, Cairo, Egypt

Lanthanide (Ln3+) doped TiO2 down-conversion photoelectrodes (Ln3+ =Eu3+ and Sm3+ ions) are used to enhance the photovoltaic efficiency of dye-sensitized solar cells (DSSC). We report on achieving fill factors of 0.67 and 0.69 and efficiencies of 5.81% and 5.16% for Sm3+ and Eu3+, respectively. This is compared to the 4.23% efficiency for the undoped-titania photoelectrodes. This enhancement is probably due to the improved UV radiation harvesting via a down-conversion luminescence process by the lanthanide ions. The structure, optical and photoluminescence properties of the down-converting photoelectrode are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM),


181

energy dispersive X-ray (EDX) and room temperature photoluminescence excitation and emission spectrofluorimetric measurements.

Keywords: Down-conversion, DSSC, Lanthanide, TiO2

Abstract:0197

Doping Sensitive Optical Scattering in Zinc Oxide Nanostructures Films for Solar Cells

Faruk Ballipinar, Ratheesh R. Thankalekshmi, Alok C. RastogiBinghamton University, State University of New York, Binghamton, New York, USA

The nanostructured ZnO thin films are used in solar cells as heterojunction window layer as well as to enhance the junction area. Nanostructures also offer advantage of light scattering property to transmit more light into the absorber layer of solar cells. The optical and light scattering property of the nanostructured ZnO thin films doped with Al and Cu have been studied. The homogeneously doped ZnO nanostructured films were synthesized by a flux sublimation technique at ~ 300°C temperature. The structural studies show hexagonal nanocrystal growth in Al doped ZnO film and nanowire structure in Cu doped ZnO film. These doped ZnO films consistently showed two direct band gaps. The low energy band gap of Al and Cu- doped ZnO films originates from the macroscopic structural feature in the film, and the higher energy band gap due to the quantum confinement of nanostructure clusters in the film. Increased transmission in the lower wavelength region is caused by the forward light scattering by the nanostructure. Simulation of the optical absorption spectra of the Al and Cu- doped ZnO films using the modified Mie scattering theory shows consistent match with the experimental absorption spectra. The results show that increased forward scattering of light could be harvested by increasing the nanoparticle density which will enhance the photocurrent generation from the thin film solar cells by using doped ZnO nanostructured film as a window layer o as a transparent conducting electrode.

Keywords: Nanostructures; Mie theory; Al and Cu-doped ZnO; solar cells.


182

Abstract:0198

Poly(3-arylthieno[3,2-b]thiophenes for Bulk Heterojunction Solar Cells

Asli Capan1, Elif Alturk Parlak2, Nesrin Tore3, Turan Ozturk4

1Istanbul Technical University, Maslak, Istabul/Turkey2The Scientific and Technological Research Council of Turkey, TUBITAK, (National Metrology Institute)

Gebze, Kocaeli/TURKEY3Gebze Institute of Technology, Gebze/Kocaeli/Turkey

4TUBITAK UME, Chemistry Group Laboratories, PBox 54, 41470, Gebze-Kocaeli, Turkey

Poly(arylthieno[3,2-b]thiophenes) (PTT) 1 – 4 were synthesized through Suzuki coupling reactions of arylthienothiophenes (TT) 5 - 10 with 2,5-diborolaneylthiophene.1 Among the polymers, solar cell devices of 1, 2 and 4 were fabricated, which had a structure of glass/ITO/PEDOT:PSS/polymer:PC61BM/Al. Bulk heterojunction photovoltaic cells were prepared as blends of PTTPh, PTTPh-OCH3, PTTPh-N(CH3)2 and PC61BM in a 1:1 ratio, which delivered power conversion efficiencies of 0.43%, 0.039% and 0.027%, respectively, without addition of additives or device optimization.

1- A. Capan, H. Veisi, A. C. Goren, T. Ozturk Macromolecules, 2012, 45, 8228 - 8236

Keywords: Thienothiophene, polythienothiophene, organic solar cell

Polythienothiophenes


183

Abstract:0199

Photostimulated Processes in Boron-doped CdS and CdS-Cu2S Structures

Vagif Novruzov1, Murat Tomakin1, Eyup Fahri Keskenler2, Zuhal Yagmur1, Gokcehan Karaca1

1Department of Physics, Recep Tayyip Erdogan University, Rize, Turkey2Department of Nanotechnology Engineering, Recep Tayyip Erdogan University, Rize, Turkey

Growth of CdS and CdS-Cu2S films doped with different concentrations of Boron has been done using spray pyrolysis method. X-ray diffraction patterns showed that the pure and B-doped samples were grown along the (100), (002), (101) plane directions with hexagonal lattice structure. With the increasing of doping concentration in CdS films after UV illumination showed a shifting to the preferable orientation of (002) plane in crystalline structures. Although it was observed a decrease in crystallite size and c lattice parameter in non-illuminated pure and B-doped CdS, it was the very opposite case for illuminated ones. After UV illumination, resistivity of undoped CdS sample was changed from 1.81×107 Ω-cm to 9.42×103 Ω-cm, but there was no significant variance in B-doped films. AFM images show that illuminated samples have more homogeneous surface, which can be attributed to a new phase (B2O3) phenomenon on the surface. The optical transmittances of the samples in this work exhibited that Boron doped ones are more transparent. Furthermore, UV application has increased the transparency of the B-doped CdS films. The photoluminescence spectra of these samples present that thin films are more durable in the presence of Boron dopant. It is reported for undoped and B-doped CdS-Cu2S films that 10 hours illumination of UV light has not affected the photoelectrical parameters (Voc and Isc) of B-doped CdS-Cu2S solar cells.

The boron has high electronegativity (2.04), and the B3+ has high Lewis acid strength (10.7) than that of Cd+2. Finally, physicochemical properties of Boron have favorable effects on films.

Keywords: CdS, CdS-Cu2S, Photostimulated, Solar cell, Thin film

Abstract:0201

Biomass Usage Like a Natural Solar Cell

Merve IlıksuDepartment of Chemical Engineering, Istanbul Technical University, Istanbul, Turkey

As the World has a great problem with emissions, clean energy sources are becoming more important. Solar energy is one of the promising alternatives. Conversion of solar energy to electricity as well as storage and transport technologies are important subjects for solar energy usage. It can be said that photosynthesis is a natural way of producing solar fuels. Sunlight is absorbed by plants, bacteria and algae. Solar power converts carbon dioxide and water to carbohydrates and oxygen. There are certain kinds of algae and a few other plant species which are very efficient at storing absorbed solar energy in the form of biomass. Photosynthesis efficiency of the plants can be up to 6% of total solar radiation.


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Using plants or algae is cost effective compared to high technology solar cells. A good example is hybrid poplar, a fast growing plant for energy forestry.

Biotechnological research also managed to improve the photosynthesis properties in a couple of different aspects. For instance, under natural conditions some algae can produce very clean hydrogen gas, which happens to be a very clean fuel too.

In this poster presentation, a survey over fast growing and effective biomass plants and their properties will be given, to highlight the importance of biomass as a medium in which solar energy can be stored efficiently.

Keywords: Biomass, natural solar panels, photosynthesis

Abstract:0202

Improvement of the Electrical Properties of the Layers of Porous Silicon Metallization by Nickel

Sonia Ben Slama, Masseoud Hajji, Hatem EzzaouiaTechnopole Borj Cedria

This work presente the influence of nickel on the surface and the absorbance of porous silicon inorder to improve the photovoltaique of a rendemanet.

porous silicon layers were elaborated by electrochemical etching of heavily deped p-typa silicon substrates.the metallization of porous silicon was carried by dip-coating in diluted aquous solution of nickel.this substrat were systematically analysed by uv-vis spectrophotometer,fourier transmission infrared spectroscopy:ftir,X-ray diffraction:XRD.

Keywords: electrical properties porous silicon nickel

Abstract:0205

Numerical analysis of Copper Indium Gallium Di-selenide (CIGS) based solar cells by SCAPS-1D

Soumaila Ouedraogo1, François Zougmore1, Jean Marie Ndjaka2

1UFR-SEA, Université de Ouagadougou, Ouagadougou, Burkina Faso2Departement de Physique, Université de Yaoundé 1, Yaoundé, Cameroun

In this work, we used a one dimensional simulation program SCAPS-1D (Solar Cell Capacitance Simulator in 1 Dimension) to investigate Copper Indium Gallium Di-selenide (CIGS) based solar cells properties. Starting with a conventional ZnO-Al/i-ZnO/CdS/CIGS structure, we simulated the parameters of current-voltage characteristics, and showed how the absorber layer thickness, hole-density and band-gap, influence the short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor (FF) and

185

efficiency of solar cells. Our simulation results showed that all electrical parameters are greatly affected by the absorber thickness (w) below 1000 nm, due to the increase of back-contact recombination and very poor absorption. Increasing hole-density (p) or absorber band-gap (Eg) improves Voc and leads to high efficiency, which value equals 16.1 % when p = 1016 cm-3 and Eg = 1.2 eV. In order to reduce back-contact recombination, the effect of a very thin layer with high band-gap, inserted near the back-contact and acting as electrons reflector, the so-called back-electron reflector (EBR), has been investigated. We found that the performance of the solar cell is very improved, when ultra-thin absorbers (w < 500 nm) are used; the corresponding gain of Jsc due to the EBR is 3 mA/cm2. Our results are in good agreement with those reported in the literature from experiments.

Keywords: CIGS, SCAPS, Simulation

Abstract:0206

The effect of annealing on nanocrystalline hydrogenated silicon deposited by PECVD at different H2 gas flows

Sana Ben Amor, Wissem Dimassi, Sonia Ben Slema, Hatem EzzaouiaPhotovoltaic Laboratory Research and Technology Centre of Energy, Borj-Cedria, Tunisia

In this paper, we have studied the effect of thermal treatment on nanocrystalline hydrogenated silicon (nc-Si:H) thin films deposited by PECVD at different hydrogen flow rates. The optical properties of nc-SiH were determinated from reflection spectra. The crystallite volume fraction and the crystallite size were calculated from Raman spectra. Besides, the type of hydrogen bonds were investigated using FTIR spectra. Finally, the carrier life time have been also studied

Keywords: Nanocrystalline hydrogenated silicon, PECVD, hydrogen flow rates, Thermal treatment


186

Abstract:0207

Solar Energy Conversion to Chemicals: Photocatalytic Selective Oxidation of 5-(Hydroxymethyl)-2- furaldehyde to

2,5-Furandicarbaldehyde in Water by Using TiO2 Nanoparticles

Oguzhan Alagoz1, Sedat Yurdakal2, Bilge Sina Tek2, Vincenzo Augugliaro3, Vittorio Loddo3, Giovanni Palmisano3, Leonardo Palmisano3

1Kimya Mühendisliği Bölümü, Mühendislik Fakültesi, Afyon Kocatepe Universitesi, 03200, Afyon, Turkey2Kimya Bölümü, Fen-Edebiyat Fakültesi, Afyon Kocatepe Universitesi, 03200, Afyon, Turkey

3Dipartimento di Energia, Ingegneria dell’Informazione e Modelli Matematici, Università degli Studi di Palermo, 90128 Palermo, Italy

5-(Hydroxymethyl)-2-furaldehyde (HMF) was selectively oxidized to 2,5-furandicarbaldehyde (FDC) in aqueous medium by using home-prepared (HP) anatase, rutile, and brookite TiO2 nanoparticles. HP samples were prepared via a sol-gel method by using TiCl4 as the TiO2 precursor. Commercial TiO2 catalysts were also used for comparison. All samples were characterized by BET specific surface area, XRD, TGA, and SEM, and the reactivity results showed that HP catalysts are predominantly amorphous and give rise to selectivities toward FDC more than twice that of commercial and well-crystallized catalysts.

HMF is a common species present in almost all sweets because sugars easily degrade to HMF. Moreover, many catalytic processes involving production of HMF from fructose, glucose, polysaccharides, and biomass feedstocks have been recently investigated. It is therefore challenging to find efficient and green synthetic methods able to transform HMF, which is a common byproduct, to valuable species.

Whereas no photocatalytic oxidation of HMF to FDC has been reported until now, the literature reports many investigations on the selective catalytic oxidation of HMF to FDC that is a widespread chemical needed to obtain many industrially relevant compounds. These processes exhibit high values of selectivity to FDC in the 60-99% range, but they do not satisfy the conditions of the “green” chemistry. The present investigation reports the first photocatalytic green oxidation of HMF to FDC. The reaction has been carried out in aqueous medium in a batch reactor by using home-prepared (HP) and commercial TiO2 photocatalysts under near-UV irradiation.

Keywords: 5-(Hydroxymethyl)-2-furaldehyde, Selective oxidation, Photocatalytic green synthesis, TiO2, 2,5-Furandicarbaldehyde

The green synthesis of 2,5-furandicarbaldehyde


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Table 1. Crystalline phase, crystallinity, physically adsorbed water, BET specific surface area (SSA), agglomerate size, andcrystallite size of the catalysts and their photocatalytic performance for the oxidation of HMF to FDC(a)

catalyst crystalphase (b)

crystal-linity (%)

ad-sorbed water

SSA agglom-erate size (nm)

crystal size (nm)

r0 ×10exp6(c)

t1/2 (d)(hours)

Selectivity (e) %

SA R 100 0 2.5 240 52 181 3.5 10.9

Merck A 74 0.5 10 170 60 62 3 12.6

P25 A:R 90 0.5 10 80 26:18 (A:R)

28 1.15 12.0

HPB B - 0.7 70 50 10.9 8.2 2.60 21.0

HPR R 12.8 0.7 105 36 6.8 2.2 13.0 25.0

HPA A 2.85 0.9 189 45 3.6 2.4 4.0 22.5

HPA (f) A 2.85 0.9 189 45 3.6 0.6 16.0 26

(a) Catalyst amount: 0.2 g L-1. Initial HMF concentration: 0.5 mM. (b) A: anatase. R: rutile. B: brookite. (c) Initial reaction rate. (d) Irradiation time needed to reach a HMF conversion of 50%. (e) Selectivity = (produced FDC moles)/(converted HMF moles) × 100 at 20% conversion. (f) Run performed in thepresence of 50 mM methanol

Abstract:0208

Metoxytriphenylamine-based hole-transporting molecular glasses for optoelectronic applications

Monika Cekaviciute1, Jurate Simokaitiene1, Juozas Vidas Grazulevicius1, Dmytro Volyniuk1, Vygintas Jankauskas2


Optoelectronic devices using organic materials as active elements involve charge transport as an essential operation process and therefore require effective charge-transporting materials. Derivatives of triphenylamine represent one of the largest and one of the most widely studied class of organic electroactive materials. In most of the applications the ability to transport positive charges of the derivatives of triphenylamine is exploited. In this presentation we reported on the synthesis and investigation of the properties of new glass-forming methoxy-substituted triphenylamine derivatives.

Coumpounds were synthesized by one step procedure i.e. by condensdation in the presence of ±-10-camphorsulphonic acid or by acid promoted Friedel-Crafts-type subsitution reaction. They were identified by IR-, ¹H NMR-, 13C NMR- and mass spectrometries. The synthesized compounds were found to constitute glass-forming materials with glass transition temperatures in the range of 82-165 ºC as characterized by differential scanning calorimetry. Time-of-flight hole drift mobilities of the glassy layers of the synthesized compounds exceed 10ˉ² cm²/Vs at high electric fields.

Keywords: Triphenylamine, Glass-forming, Photophysical properties, Charge-transporting


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Synthesized coumpounds structures

Abstract:0209

Effect of electrostatic field on morphology development of Bulk hetrojunction layer in polymer solar cells

Fatemeh Davoudi1, Milad Mehranpour1, Rasul Ajeian2

1Department of polymer, Islamic Azad University, Science and Research Branch, Iran2Department of Physic, Science and Technology University, Iran

Polymeric solar cells are one of the most interesting subjects in recent years because of their potential as a low cost photovoltaic device. For efficient bulk hetrojucntion (BHJ) solar cells we need a three dimensional co-continues homogeneous morphology in active layer. There are several researches on the effect of annealing time, annealing temperature and composition ratio.

The aim of present work was to investigate the effect of electrostatic field as morphology controller of P3HT/PCBM bulk hetrojucntion layer during vaporizing of solvent at spin coated active layer.

For reaching to this purpose a device equipped with electrostatic field and temperature control at vacuum or inert atmosphere was designed.

All the samples were prepared by spine coat procedure and transfer to designed device for solvent vaporizing and pre-annealing under preset atmosphere, temperature and electrostatic fields.

Morphology of final active layers investigated by SEM, then active layers were assembled at physical vapor device (PVD), the structure of the BHJ solar cell was (GLASS/ITO/PEDOT:PSS/P3HT:PCBM/LiF/AL), and efficiency (PCE%) of final assembled solar cell was compared.

Keywords: Solar cells, Polymer, Morphology,hetrojucntion


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Abstract:0212

NanoArchitecture: A Strategic Approach to Sustainable Nanomaterial Design for Energy Harvest

Beri Nsoyani MbenkumCentro Nacional de Microelectrónica (IMB-CNM), Department of Micro & Nano Systems, Campus UAB,

08193 Bellaterra (Barcelona), Spain

Substantial advancement in the development of efficient solar energy systems is heavily reliant on the ability of scientists to engineer the architecture of the materials, via non-toxic, sustainable exploitation of natural and artificial resources. Clean solar energy has huge long-term global benefits: It will increase energy security through reliance on indigenous, inexhaustible and mainly import-independent resource, enhance sustainability, reduce pollution and lower energy consumption costs.

Despite a global awareness on the dire need for solar energy, not all countries are readily adopting the technology. Majority of countries with the convenient climate can´t afford the existing expensive technologies while those with the financial resources haven’t suitable climatic conditions to benefit from the technology. Designing affordable, efficient solar energy systems requires branching out to unprecedented, platforms, in order to expand their hemispherical use is vital to compensate the performance versus cost dilemma.

Nanomaterials manifest exotic physical properties not exhibited in the corresponding bulk material. The condition(s) under which a nanomaterial forms tailors its structure and property. Hence, via tunable nanomaterial architecture, solar technology has potential to advance considerably.

Silicon (Si) is non-toxic, naturally abundant and the most established material in solar energy systems. This presentation addresses the development of silicene nanotubes (SiNTs), an allotrope of Si. The architecture of SiNTs can be tailored in order to trigger physical properties relevant for solar energy harvest. To enhance light trapping in ultrathin solar cells, it is shown how the plasmonic properties of gold nanoparticles are tuned without changing their size or shape.

Keywords: Silicene Nanotubes, Self-Assembly, Nanoarchitecture, Nanoplasmonics, chemical vapor deposition


190

Abstract:0213

Indium free colloidal CuZnSnSe1-xSx Nanocrystals

Mahmut Kus1, Faruk Özel2, Sumeyra Buyukçelebi2, Mustafa Ersöz3, Niyazi Serdar Sariciftci4

1Department of Chemical Engineering, Selcuk University, Konya, Turkey2Advanced Technology Research and Application Center, Selcuk University, Konya, Turkey

3Department of Chemistry, Selcuk University, Konya, Turkey4Linz Institute for Organic Solar Cell, Johannes Kepler University, Linz, Austria

CuZnSnSe1-xSx (CZTS) nanocrystals (NCs), as an alternative for CIS, have a great attention due to its possible application potential instead of CIS crystals. Moreover, colloidal forms of such crystals make them solution processable materials for thin film device applications. Herein, we report synthesis of different colloidal kesterite nanocrystals and their performance in PCBM based bulk heterojunction solar cells. XRD, TEM and SEM techniques were used in structural analysis (Figure 1). Optical and electrochemical properties were investigated. Finally NC:PCBM bulk heterojunction solar cells were fabricated and characterized to optimize the best device concepts. The best device was observed to be ITO/PEDOT:PSS/CZTS:PSCM blend (1:10)/Al concept that shows 280 µA/cm2 with 300 mV Voc and FF of 0.38. Conversion efficiency was calculated to be 0.03%. Although the efficiency is poor, we have to emphasize that all materials are solution processable and low cost. So these concepts must be investigated to improve the efficiency.

Keywords: Kesterite, CZTS, hybrid solar cell

Figure 1

XRD patterns of CZTS, CZTSe and CZTSeS nanocrystals.


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Abstract:0214

Performance research of space heating system for sauna applications

Bashar Mudhaffar Abdullah1, Jumta Salimon3, Abdulrahman Th. Mohammad2, Sohif Bin Mat1, M. Y. Sulaiman1, K. Sopian1

1Solar Energy Research Institute, University Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia2Department of Mechanical Engineering, Baqubah Technical Institute, Foundation of Technical Education,

Baghdad, Iraq3School of Chemical Sciences and Food Technology, Faculty of Science and Technology, University

Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia

The application of solar energy, space heating becomes technically feasible and economically competitive. In this paper, space heating system designs and installs to study the feasibility of space heating system for sauna applications in Malaysia. The system consists of an energy-collection cycle and an energy radiating cycle. This paper presents the results of theoretical and experimental performance of the system and its principle components. The results show that the temperature inside the space heating varied between 39 oC and 51 oC.

Keywords: heating system; sauna applications

Abstract:0216

Pulsed Laser Deposited Cu2O/ZnO heterojunction for photovoltaic applications

SFU Farhad1,2, David Cherns1

1HH Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK.2Industrial Physics Division, BCSIR Laboratories,Dhaka 1205, Bangladesh.

There has been renewal and increasing interest in fabricating and studying for chemically stable ZnO/Cu2O junction as the starting materials are inexpensive, widely abundant, and non-toxic more importantly high theoretical efficiency of Cu2O based single photovoltaic cell (~20%) although best performing cell of this junction have not exceeded 4% to date [1]. For highly efficient n-ZnO/p-Cu2O based solar cell, one of the key requirements is to produce single phase highly-crystalline ultrathin metal oxides absorber layer to attain high transport properties and low recombination losses thereby facilitate poor minority carrier diffusion length of the active layer. Both ZnO and Cu2O high quality thin films were grown at relatively low temperature by a simple pulsed laser deposition system to realize highly efficient solar cells. Deposition condition as well as post annealing of the individual films were found to be crucial to control optical, structural and electrical properties of the individual films. A number of solar cells were made and characterized to investigate how the cell properties depend on structure and composition of each layer.

Reference:

[1]. Yuki Nishi, et al., Thin Solid Films (2012)

Keywords: Inorganic Solar Cell, Pulsed Laser Deposition, Copper(I) Oxide


192

Abstract:0218

Chemically modified polypyrrole electrodes for electrochemical CO2 reduction

Stefanie Schlager1, Engelbert Portenkirchner1, Dogukan Hazar Apaydin1, Jacek Gasiorowski1, Markus Clark Scharber1, Reghu Menon2, Niyazi Serdar Sariciftci1

1Linz Institute for Organic Solar Cells (LIOS), Institute of Physical Chemistry, Johannes Kepler University Linz, Austria

2Department of Physics, Indian Institute of Science, Bangalore 560012, India

Carbon dioxide is one of the major greenhouse gases and contributes greatly to global warming. In this work a study on electrochemical carbon dioxide reduction as a clean and renewable energy source is presented. A comparison of pyridine treated polypyrrole (PPy) electrodes, applied on different substrates, is shown. In contrast to previous research [1,2] an organic semiconductor is used to support the pyridine catalyst for CO2 reduction [3]. Organic semiconductors like polymers provide several favorable properties, such as unlimited availability, tunable bandgaps and easy processability. At first on the working electrodes, such as platinum foil or carbon felt, polypyrrole is electropolymerized. Further PPy is modified with pyridine, as supporting catalyst. In the electrochemical setup a Pt counter electrode and a Ag/AgCl quasi reference electrode were used. Cyclic voltammetry (CV) measurements were performed to confirm catalytic properties of the PPy with incorporated pyridine after purging the electrochemical setup with N2 and CO2, respectively. Comparison of the cyclic voltammograms recorded during CO2 reduction on the pristine PPy electrodes as well as at the same electrode after modification with pyridine, show that the electrochemical reduction of CO2 is catalyzed by pyridine.

1 E. Barton Cole, P. Lakkaraju, D. Rampulla, A. J. Morris, E. Abelev, A. B. Bocarsly, J. Am. Chem. Soc., 132, 11539-11551(2010).2 E. Portenkirchner, K. Oppelt, C. Ulbricht, D. A. M. Egbe, H. Neugebauer, G. Knör, N. S. Sariciftci, J. Organomet. Chem., 716, 19-25 (2012).3 S. Cosnier, A. Deronzier, J. C. Moutet, J. Electroanal. Chem., 207, 315-321 (1986).

Keywords: Co2 reduction, polypyrrole, catalysis, modified working electrode


193

Abstract:0221

Extensive Study on Defect Structure of ZnO for Solar Energy Conversion and Spintronics*

Kasim Ocakoglu1, Selma Erat2, Saadet Yildirimcan1, Fatih M. Emen3, Emre Erdem4

1Advanced Technology, Research and Application Center, Mersin University, Mersin, Turkey.2Department of Electrical-Electronics, Faculty of Engineering, Toros University, Mersin, Turkey.

3Department of Chemistry, Faculty of Arts and Science, Mehmet Akif Ersoy University, TR 15030, Burdur, Turkey.

4Institut für Physikalische Chemie I, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg, Germany.

Zinc Oxide (ZnO) is an attractive material particularly in the area of photonics, electronics, acoustics and sensing. We have been working on both thin films and nanopowder of ZnO for solar energy conversion and new spintronic devices (spin LED’s, spin valve transistors), respectively. The thin films were produced by following procedure: firstly ZnO seeds were deposited on glass substrates by spin coating technique. After drying these seeds, the hydrothermal technique (1.5 h, 75 ºC) was followed in order to get thin films. The field emission-SEM images show that the substrate is coated with a highly uniform and dense array of ZnO nanorods, with an average diameter of 70 nm and length of ~500 nm. The photoconductivity and electrical measurements of these vertically aligned ZnO nanorod arrays is still on going issues. On the other hand, we investigate the defect structure of ZnO nanopowder (produced by hydrothermal technique) depending on growing time and the concentration of Mn doping by Multi-frequency Electron Paramagnetic Resonance (EPR) Spectroscopy (X-band (9.47 GHz) and Q-band (34.2 GHz). The crystallite size of ZnO nanopowder increases from 25 nm to 50 nm with increasing growing time from 1h to 36h. The dislocation density and strain of the samples were calculated by using the X-ray powder diffraction results.

* This research has been financially supported by The Scientific and Technological Research Council of Turkey, TUBITAK (Grant: 110M803) in the framework of European Science Foundation (ESF-EUROCORES-EuroSolarFuels-10-FP-006) and the Deutsche Forschunsgemeinschaft, DFG (Grant: Er 662/1-1).

Keywords: ZnO, EPR, semiconductor spintronics, defect structure.


194

Abstract:0223

An Optimization of PbS Quantum Dots as a Light Harvesting materials

Shaimaa Ali1, Philipp Stadler2, Sergii Yakunin3, Wolfgang Heiß3, Salah Sabry Ahmed Obayaa1, Mabrouk Kamel El Mansy4, Daniel Ayuk Mbi Egbe2,

Nayazi Serdar Sariciftci2

1 Center for Photonic and Smart Materials (CPSM), Zewail City of Science and Technology, Sheikh Zayed District, 6th of October City, 12588, Giza, Egypt

2Linz Institute for Organic Solar cells, Physical Chemistry, Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria

3Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenberger str. 69, 4040 Linz, Austria

4Department of Physics, Faculty of Science, Benha University, Benha, Egypt.

Lead sulfide quantum dots exhibit unique spectral features that combine solution processing and photon harvesting by matching the band gap to the solar spectrum. In our study, we applied hot-injection synthesis to yield colloidal quantum dots stabilized with oleic acid with an excitonic absorption at 1.3 eV. For the photovoltaic device, thin films have been fabricated by means of dip coating in multi-step layer by layer process following an atomic ligand passivation route. The as-prepared quantum solid shows excellent electronic properties including narrow trap bands and high mobility – as characterized by transient photo-induced absorption and field-effect transistors. The time-resolved PL measurements show that atomic ligands do not quench emission of PbS nanocrystals drastically so they are more preferable for photovoltaic application than other type of ligands used to improve electronic transport in quantum dots. We studied photoconductivity properties of quantum dots after ligand exchange and found that although the samples have moderate photoconductive gain they show rather high bandwidth of the response that makes this material promising for application in fast photodetectors. We found that both the film quality and the optoelectronic features make the system most interesting for a single-junction photovoltaic device.

Keywords: Quantum dots, PbS, Solar cells, Time-resolved PL


195

Abstract:0224

Antireflection coating combining silicon nitride and silicon nanoparticles

Modou Beye, Amadou Seidou MaigaDepartment of Applied Sciences and Technology, University Gaston Berger, Saint Louis, Senegal

Scattering from nanoparticles, mostly metal, has emerged as an efficient light trapping technique in solar cells. Metal nanoparticles embedded in a dielectric layer and patterned on it or directly onto a substrate have been found to reduce the reflectance from a solar cell active layer surface over a broad spectral range. Recently, a new approach enabling further reduction of the reflection from the silicon surface and not involving metals has been proposed, in which a two-dimensional periodic array of silicon nanoparticles on a silicon nitride spacer layer is used. Simulations and experimental results showed an average reflectance lower than 2% over a wide spectral range and for angles of incidence up to ± 60°. However, in most publications, a Si3N4 spacer layer of fixed refractive index 2.0 is used. Thus, the effect of the spacer layer refractive index is not considered. In this paper, we investigate this effect on the performance of the above mentioned antireflection coating. The effect of embedded silicon nanoparticles is also studied. Simulated results show that a refractive index of 2.2 provide better performances, yielding a weighted reflectance of 4.3% in the spectral range 300 – 1100 nm. A relative increase of 6.1% in the short circuit current density over a silicon solar cell with the standard Si3N4 coating is predicted. Stability of the reflectance under oblique incidence for angles lower than 40° is observed. Conversely, the embedded silicon nanoparticles are found to yield a negative effect.

Keywords: Silicon nitride; Silicon nanoparticles; Antireflection coatings; Solar cells


196

Abstract:0225

Thermal and economical analysis of the solar preheating of steam boiler feed water

Fabrício dos Santos Dantas, Manoel Antônio da Fonseca Costa FilhoPPG-EM/UERJ, Prog. Pós-grad. Eng. Mecânica, Universidade Estadual do Rio de Janeiro, Brazil

This paper presents a technical and economical feasibility assessment of solar preheating of steam boiler feed water for opened vapor systems. Data from a medium sized dairy industry in Rio de Janeiro State (Brazil) is used to compose a case study.

Forty two computer simulations were carried out in TRNSYS to the solar heating system adopted, in a range of design parameters corresponding to the 5% best economical results of a series of 2700 simpler simulations (φ-f-chart method), programmed on MATLAB.

State’s capital typical meteorological year hourly weather data was used.

Revenue was based on the avoided consumption of fuel for natural gas, LPG and fuel oil. Investment cost was composed from both commercial and literature values.

Final economical assessment showed unfavorable, but the results made it possible to address environmentally sound public policies to encourage industrial solar energy use.

Keywords: thermal solar dairy industry

Configuration of solar heating system

General configuration of the simulated feed water solar heating system. All simulations use this configuration, with different design parameters. This figure will be enhanced for the poster.

Storage Volume Cost

This is an example of the curve fittings used to address aquisition scale economy in the system investment cost. It’s composed of both commercial and literature data.


197

Abstract:0228

A TCO-Free Back Contact Dye Sensitised Solar Cell

Joseph Giorgio, Grant Mathieson, Gordon G. Wallace, David L. OfficerIntelligent Polymer Research Institute, University of Wollongong, Wollongong, Australia

Transparent conductive oxides (TCO) in dye-sensitised solar cells (DSSCs) place considerable limits on the size of a cell module, leading to a number of module development challenges. These challenges can be overcome if the TCOs are replaced with metal electrodes. Metal cathodes have been investigated in traditional DSSC constructions and metal anodes can be utilised in back-illuminated DSSCs. However, the back-illuminated design suffers from a drop in efficiency due to the electrolyte light absorption. If metal electrodes are utilised for both the cathode and anode considerable advantages to devices can be obtained, and many obstacles in regards to cell design can be overcome.

The back contact DSSC (BCDSSC) has been reported in a number of papers, which provide device efficiencies as high as 8.4%. However, these designs typically limit scalability. We have developed a new design of BCDSSC using a perforated titanium foil anode affording a device efficiency of over 5% in low light conditions (10% of AM 1.5) for a 1 cm2 cell. The advantages of this BCDSSC variant include the total elimination of TCO glass, flexible devices can be manufactured and the high anode conductivity allows scalability.

Keywords: Dye Sensitised Solar Cell, Back Contact, Solar Photovoltaic, TCO-Free

Abstract:0232

Structure and Size controlled Nanocrystalline ZnO by Microwave Assisted Hydrothermal Reaction and Their

Application to Dye-sensitized Solar Cell (DSSC)

He Sun, Tsukasa YoshidaDepartment of Research Center for Organic Electronics (ROEL), Yamagata Univercity, Yonezawa, Japan

Efficiency improvements in flexible DSSCs are expected by employing tailor-made ZnO. We have developed a method to quickly crystallize ZnO by microwave assisted hydrothermal reactions. Structure of the nanocrystals not only for their shape and size, but preferentially exposed crystal facets, could significantly influence important parameters such as dye adsorption capability, electron transporting property and electron lifetime.

Aqueous solutions containing 0.2 M of Zn(CH3COO)2 and 0 to 1.0 M of triethanolamine (TEOA) as structure directing agent (SDA) were used as starting mixtures to which appropriate amount of KOH was added to adjust pH between 8 and 13. Reaction temperature of 150°C was maintained for 30 min. Precipitates obtained after the reaction was centrifuged, washed several times and dried in oven at 100oC.


198

Well crystallized ZnO was obtained in all cases as confirmed by XRD. Morphology and particle size were checked by SEM. The influence of pH and that of the TEOA/Zn(CH3COO)2 ratio are shown in Figs. 1 and 2, respectively. At pH 8, dumbbell-like particles exceeding 10 μm were obtained that reduces the size and changes to a football-like shape at pH 9. Above pH 10, the particle became less than 200 nm and crystallize in a hexagonal bi-pyramidal shape, indicating preferential exposure of (103) facets. For TEOA/Zn(CH3COO)2 ratio=2, we found size reduction down to ca. 50 nm. When more or less TEOA was used, the size tended to increase, although excess of TEOA obviously caused aggregation to form spherical particles as assemblies of smaller particles.

Keywords: ZnO,Dye-sensitized Solar Cell,Microwave,Hydrothermal reaction

Fig.1 The influences of increasing pH on the size and morphology of ZnO.

Fig.2 The influences of changing the concentration ratio of TEOA/Zn(OAc)2 on the size and morphology of ZnO.


199

Abstract:0233

Trace magnetic impurities and their possibly strong influence on magnetic properties in organic materials-OMAR effect

Marek HavlicekJohannes Kepler University, Linz Institute For Organic Solar Cells

The idea to produce a strong intrinsic ferromagnetic organic material without additional doping with 3d elements was a dream of many scientists around the world for decades. Especialy important would be such a material when being magnetic above room temperature. Its technological applications would be enormous such as magnetic touch screens, spin valves, position detectors etc.

Most of the concepts rely on unpaired spins (dangling bonds) and their ferromagnetic interactions. Such materials show usually very weak magnetization. Moreover the existence of ferromagnetic organic material at RT is questionable. More natural would be

to attribute the origin of the ferromagnetism in such materials to trace ferromagnetic impurities such as iron and its allotropes. These contaminants are almost always present and their typical amounts range from units to hundreds of ppm. It was shown recently that many so called organic ferromagnets were actually iron contaminated.,

The presence of such magnetic impurities may then have a significant effect on another strongly discussed phenomenon-Organic Magnetoresistance (OMAR). Since its origin is not still well understood we investigate the effect of trace amounts of magnetic impurities in different organic materials and different geometries in a magnetic field on magnetoresistance. For magnetic impurity analysis and its behaviour at different temperatures we use Electron Spin Resonance (ESR).

Keywords: OMAR, magnetoresistance, organic polymer, ESR

Abstract:0234

Synthesis of Hydrogenated Amorphous Carbon (a-C:H) Thin Film by Single RF Plasma System

Dogan Mansuroglu1, Kadir Goksen2, Sinan Bilikmen1

1Physics Department, Middle East Technical University, Ankara, Turkey2Physics Department, Duzce University, Duzce, Turkey

Methane (CH4) plasma was used to pro duce hydrogenated amorphous carbon (a-C:H) films by a single capacitively coupled radio frequency (rf) powered plasma system. There are two parallel electrodes inside the chamber on top of each other; upper one has rf power with 13.56 MHz frequency and the other one is connected to the ground. The thin films were deposited on glass slides with different size and on silicon wafers. The influence of the plasma species to film characteristics was studied by changing the plasma parameters; rf power (100-300 W), CH4 flow rate (2-5 sccm), deposition time (15, 30 min), at constant pressure of 0.2 torr. The changes of plasma chemistry during the deposition were investigated by optical emission spectroscopy (OES). The emission lines of the species of CH, C, H and H2


200

were recorded. The sp3-to-sp2 hybridization ratio and H content play a significant role in determination of the chemical properties of films in the plasma. The chemical structural properties were examined by fourier transform infrared (FTIR) spectroscopy. The optical properties of the films were explored by UV-visible spectroscopy and thickness was measured by a profile meter. The film quality and deposition rate were increased by raising the power and the flow rate. Ionization rate shows higher values at higher power and increasing the amount of CH4 inside the chamber also increases the ionization. The deposition rate was increased by increasing the deposition time and thickness of the films on thicker substrates was higher than that of thinner substrates.

Keywords: Plasma, polymer thin film, methane

Abstract:0235

Synthesis and numerical modeling of Cu2ZnSnS4 (CZTS) thin film based absorber for photovoltaic applications

Herve Joël Nkuissi Tchognia1, Youssef Arba1, Jean Marie Ndjaka2, Bouchaib Hartiti1, Abderraouf Ridah1, Philippe Thevenin3

1LPMAER, Department of Physics, Hassan II Mohammedia University, Mohammedia, Morocco2Department of Physics, University of Yaoundé I, Yaoundé, Cameroon

3LMOPS, University of Lorraine, Metz, France

Copper zinc tin sulfide (Cu2ZnSnS4, CZTS) has attracted significant attention in over recent years as a next generation of absorber materials in thin film solar cells due to the high natural abundance of all constituents, tunable direct band gap energy and large absorption coefficient [1].

In this work, we report the synthesis and the application of Cu2ZnSnS4 (CZTS) as absorber material in heterojunction solar cells. CZTS thin films were synthesized using a solution route namely sol-gel, which is a simple and low cost method for a large production of thin films materials. The sol-gel precursor solution was made from metal salts of copper (II) chloride (CuCl2), zinc (II) chloride (ZnCl2), Tin (IV) chloride (SnCl4), and thiourea (CS (NH2)2) and a mixture of ethanol/water as solvent. The spin-coated films were annealed in air at temperatures above 300°C. The morphological and structural properties of the absorber layer were analyzed by Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). From numerical simulations using the Analysis of Microelectronic and Photonic Structures (AMPS-1D) simulator, we evaluated the overall properties of the CZTS solar cell.

Keywords: Cu2ZnSnS4, sol-gel, spin coating, photovoltaic material, numerical simulation, AMPS-1D.


201

Abstract:0236

Investigation of Physical Properties of Self-assembled Zinc chlorin Nanorods Suitable for Artificial Light-Harvesting

Materials*

Kasim Ocakoglu1, Ersan Harputlu1, Anna Tarnowska2, Daniel T. Gryko2

1Advanced Technology Reseach&Application Center, Mersin University, Ciftlikkoy Campus, TR33343, Yenisehir, Mersin, Turkey.

2Warsaw University of Technology, Faculty of Chemistry, Noakowskiego 3, 00-664 Warsaw, Poland.

Photosynthetic light-harvesting (LH) antennas have attracted much attention from the viewpoint of their beautiful supramolecular nanostructures. This construction of highly ordered supramolecular structural design and organized on surfaces across multiple length scales represents an important issue within the fast-growing field of light harvesting devices. One of the most promising methods for the construction of these supramolecular assemblies relies on the self-organization ability of π-conjugated systems. Supramolecular nanostructures of self-aggregated zinc chlorin (ZnChl) derivatives have been widely investigated by spectroscopic and microscopic techniques. The semisynthetic ZnChl self-aggregated in nonpolar organic solvents to give precipitates and molecular cables formation and stability of the rod nonpolar organic solvent. The resulting insoluble self-aggregated solids were investigated on a variety of substrates, including hydrophobic, neutral and hydrophilic substrates, by visible absorption, as well as AFM, conductive AFM (C-AFM) and STM techniques. The self-aggregates of ZnChls formed rods with an approximately 6-12 nm diameter and wires with further extended growth of the rods. After all investigating molecular cables forms on the different substrate, to monitor the transport of charges along individual nanowires, we applied C-AFM method. The conductivity result of zinc chlorophyll nano-wires was 30 pA (picoampere). So these nano-wires appear highly promising for organic photovoltaics and micro-electronics.

* This research has been financially supported by The Scientific and Technological Research Council of Turkey, TUBITAK (Grant: 110M803) and Polish National Science Center (844/N-ESF-EuroSolarFuels/10/2011/0) in the framework of European Science Foundation (ESF-EUROCORES-EuroSolarFuels-10-FP-006).

Keywords: Artificial light-harvesting antennas, zinc chlorins, self-aggregation, chlorophyll, nanostructures.


202

Abstract:0239

Application of Carbon Nanotubes as Transparent Electrodes For Solar Cells

Osman Urper, Elif Arici, Nilgun K.yavuzDepartment of Energy, Istanbul Technical University, Istanbul, Turkey

One of the key parameter for the efficiency of the solar cell is the light harvesting. Hereby, together with the absorbance properties of the active layer, the optical transmittance of the front-electrode plays an important role.

Indiun tin oxide (ITO) is the mostly used electrode material for organic solar cells. In long term, because of the rarity of Indium as source material, there is a need to replace ITO by alternatives. Indium tin oxide (ITO) is not only expensive in fabrication but also mechanically brittle, which increases the fabrication cost and also limits the flexibility of solar cell devices. In recent years, several transparent electrode materials are tested to replace ITO. Among these materials, carbon nanotubes (CNTs), seems to be a promising alternative having its unique features such as optical transmissions not only in visible but also in IR range of the sun light together with its electrical and flexibility properties.

In this poster, we will introduce the synthesis methods of single and multiwalled carbon nanotubes, and present the fabrication methods of transparent CNT layers from solution. We will characterize the transparency, surface morphology and electrical properties of the layers and discuss its advantages for photovoltaic applications.

Keywords: CNTs, Organic Solar cell, ITO, CVD

Abstract:0240

Optical Characterization of PVK/ ZNSE Hybrid Nanocomposites for Photovoltaic Application

Aida Benchaaabne1, Ziad Benhamed1, Mohamed Abderahmane Sanroury2, Fayçal Kouki1, Andreas Zeinert3, Habib Bouchriha1

1Department of Physics, Elmanar University, Tunis,Tunisia2Department of Chemistry, Elmanar University, Tunis,Tunisia

3Department of Physics, Picardie Jules Verne University, Amiens,France

Recently, polymer/inorganic nanocomposites have attracted much attention due to their low cost, substrate flexibility [1], ease processing [2] and size tunable absorption-emission.

A wide variety of inorganic semiconductor materials is developed such as cadmium selenide CdSe, cadmium telluride CdTe and zinc selenide ZnSe[3].For the polymer component, polyphenylenevinylenes and their derivatives are mostly applied in electronic devices, among these derivatives, Poly(N-vinylcarbazole) (PVK) is a good hole transporting material in photovoltaic devices [4]. It has been mixed with inorganic compounds to achieve a good conductivity [5] for new promising optoelectronic devices.

In this work, optical properties of hybrid organic/inorganic layers PVK/ZnSe are investigated as a function of the nanoparticle volume fraction by using the effective medium (EMM),the layers are deposited by


203

spin coating method on glass substrate and their transmission and reflection spectra are performed in the range of 200-800nm. Optical constants such as index reflection n and extinction coefficient k are extracted and injected in the EMM formula to determine dielectric permittivity and absorption coefficient. The optical band gap of the hybrid structure is also obtained and it is dependence with nanoparticle volume fraction. We show an increase of the conductivity after ZnSe doping (6.6 10-11Ω-1.cm-1), depending on ZnSe concentration. Structural characterisation of the PVK/ZnSe nano-composite films is investigated by scanning electron microscopic (SEM).

Keywords: optical properties; nanocomposite films;PVK;ZnSe nanoparticles;energy band gap

Abstract:0241

Photovoltaic Effect of Nanostructured TiO2 Layers in Dye Sensitized Solar Cells

Sule Erten ElaEge University, Solar Energy Institute, 35100, Bornova-Izmir, Turkey

Hybrid solar cells are typically composed of an electron transporting inorganic semiconductor material and a sensitizer material [1, 2]. A sensitizer, as the light-harvesting component in a dye-sensitized solar cell (DSSC), is of paramount importance to photovoltaic performance. The sensitizer is attached to the surface of a mesoporous wide band-gap semiconductor serving as electron transporter. The critical factors that influence sensitization are the excited-state redox potential, which should match the energy of the conduction band edge of the oxide, light excitation associated with vectorial electron flow from the light-harvesting moiety of the dye toward the surface of the semiconductor surface, conjugation across the donor and anchoring groups, and electronic coupling between the lowest unoccupied molecular orbital (LUMO) of the dye and the TiO2 conduction band. [1-3]. In this study, metal-free organic sensitizer comprising donor, electron-conducting, and anchoring groups is engineered at a molecular level and synthesized for sensitization of mesoscopic titanium dioxide injection solar cells. In order to see the TiO2 thickness dependence study of the triphenylene diamine based sensitizer on photovoltaic properties, we have fabricated dye sensitized solar cells having TiO2 films of various thicknesses. TPD-sensitized solar cell devices using a 10 (transparent) + 4 (scattering) μm thin TiO2 layer yielded a short-circuit photocurrent density of 7.70 mA/cm2, an open-circuit voltage of 800 mV, and a fill factor of 0.54, corresponding to an overall conversion efficiency of 3.34 % under standard AM 1.5 sun light.

Keywords: Dye sensitized solar cells, organic dye, TPD

Fig. 1. Schematic drawing for TiO2 layers and efficiency


204

Abstract:0243

Influence of magnetic field on the electrical parameter of a bifacial silicon solar cell front side illuminated by a

multispectral light under steady state

Armel Duvalier Péné1, Moustapha Sane2, Laurent Bitjoka3, César Kapseu3, George Elambo Nkeng4, Bouchaid Hartiti1, Gregoire Sissoko2

1Department of Physics,Hassan II Mohammedia-Casablanca University, Mohammedia, Morocco2Department of Physics, University Cheikh Anta Diop, Dakar, Senegal

3National Advanced School of Agro-Industrial Sciences, University of Ngaoundere, Ngaoundere, Cameroon4National School of Public Works of Yaounde, Yaounde, Cameroon

This paper presents the influence of external magnetic field on the electrical parameters of a bifacial silicon solar cell under steady state and front side illuminated by a multispectral light. Based on the continuity equation, excess minority carrier’s density, photocurrent density and photovoltage have been determined. This lead to the shunt and series resistances and the diffusion capacitance of the bifacial cell.

For all the studied parameters, we exhibited the effect of the external magnetic and the operating point of the cell through the junction recombination velocity

Keywords: Bifacial, magnetic field, capacitance, shunt resistance, serie resistance

Abstract:0244

Fabrication of Thin Film Nanocrystalline TiO2 Solar Cells using Ruthenium Complexes with Carboxyl and Sulfonyl Groups

Sule Erten Ela1, Kasim Ocakoglu2

1Solar Energy Institute Ege University, Bornova, 35100 Izmir, Turkey2Advanced Technology Research & Application Center, Mersin University, Ciftlikkoy Campus, TR-33343

Yenisehir, Mersin, Turkey

Dye sensitized solar cells based on nanocrystalline TiO2 electrodes have attracted intensive interest for scientific and industrial applications due to their high photo to electricity conversion efficiency and low production cost [1, 2]. Also, metaloxide nano-particle layers are of extensive use in the organic photovoltaics (OPV), as a hole blocking layer in inverted geometry bulk-heterojunction (BHJ) solar cells. One of the essential strategies for improving the performance of solar cells is provided by modification of the organic or metalorganic dyes [3, 4].

In this study, two ruthenium complexes with carboxyl and sulfonyl groups have been synthesized, [RuII(L1)2(NCS)2] RuIIbis(4,7-diphenyl-1,10-phenanthroline-disulfonic acid disodium salt)-di(thiocyanate) [K313], [RuII(L1)2(dcbpy)] RuII bis(4,7-diphenyl-1,10-phenanthroline-disulfonic acid disodium salt)(4,4´-dicarboxy-2,2´-bipyridyl) [K314] as photosensitizers. UV-Vis, fluorescence emission, AFM and CV measurements are also supplied for ruthenium complexes. Photovoltaic properties of


205

dye sensitized nanocrystalline semiconductor solar cells based on Ruthenium complexes which bear carboxyl and sunfonyl groups have been tested under standard AM 1.5 sunlight. Under the standard global AM 1.5 solar conditions, K314 and K313-sensitized solar cells demonstrate short circuit photocurrent densities of 14.92 mA/cm2 and 11.23 mA/cm2 and overall conversion efficiencies of 5.09% and 4.02%, respectively.

Keywords: Dye sensitized solar cells, nanocrystalline TiO2, Ruthenium complexes

Fig. 1. Ground State Optimization at B3LYP/LANL2DZ

Abstract:0245

Photovoltaic Applications of Polymer/Multiwalled Carbonnanotube Composites

Dolunay ŞakarDepartment of Chemistry, Yildiz Technical University, İstanbul, Turkey

In order to improve the conversion efficiency, the major research in third-generation photovoltaic cells is directed towards absorbing more sunlight using nanotechnology, for example ‘carbon nanotubes (CNTs)’, ‘quantum dots (QDs)’, and ‘hot carrier’ solar cells. CNTs have been identified as a revolutionary material system with the potential to transform the electronics industry and integrated in organic photovoltaic devices both as an electron acceptor material and as a transparent electrode.[1]

In this study, solar cells based on polymer/multiwalled carbon nanotube composites (MWCNT) of different configurations were prepared and characterized by optical and electrical techniques to probe the properties of organic solar cells fabricated from P3HT and PCBM bulk-heterojunction by adding polymer/MWCNT composites[2].

I am grateful to Prof. N.S. Sariciftci to give me the visiting opportunity at LIOS and thank to Higher Education Council of Turkey (YÖK) for financial supports.

References[1] T. K. Manna and S. M. Mahajan Nanotechnology in the Development ofPhotovoltaic Cells, 1-4244-0632-3/07/$20.00 ©2007 IEEE.[2] Dolunay SAKAR, Sven Pegel, Liane Häußler, Jürgen Pionteck, Petra Pötschke, Brigitte Voit, “ Electrical, morphological, thermal, and mechanical characterization of melt mixed polyarylene/multiwalled carbon nanotubes composites and blends with poly(phenylene oxide)”, Polymers for Advanced Technologies.

Keywords: polymer, multiwalled carbonnanotubes, solar cells


206

Abstract:0246

CdTeSe and CdTe/CdS quantum dots-sensitized TiO2 photoelectrodes

Canan Başlak1, Mahmut Kuş2, Yunus Çengeloğlu1, Mustafa Ersöz1

1Chemistry Department, Selcuk University, Konya, Turkey2Chemical Engineering Department, Selcuk University, Konya, Turkey

Quantum dot (QD) sensitized solar cells have been extensively studied because they are alternative materials with low cost than existing silicon cells. Semiconductor QDs such as CdS [1], CdSe [2], PbS [3] InAs and InP have been used as sensitizers that absorb light in the visible region. QDs have a higher absorption coefficient than organic dyes [4], so they are reduce the dark current and increase the overall efficiency of a solar cell [5]

In this study, in order to increase the incident photon to current conversion efficiency of solar cells, the effects of CdTeSe and CdTe/CdS nanocrystals as sensitizer layer on TiO2 have been investigated. The performances of solar cells were compared with synthesized nanocrystals with different composition. I-V measurement results of solar cells based CdTe/CdS and CdTeSe, are shown in Figure a) and b).

References

1) Chang, C. H.; Lee, Y. L. Appl. Phys. Lett. 2007, 91, 053503.2) Rincon, M. E.; Jimenez, A.; Orihuela, A.; Martinez, G. Sol. Energy Mat. Sol. Cells 2001,70, 163.3) Plass, R.; Pelet, S.; Kruger, J.; Gratzel, M.; Bach, U. J. Phys. Chem. B 2002, 106, 7578.4) Menny Shalom, Snir Dor, Sven R hle, Larissa Grinis, and Arie Zaban, J. Phys. Chem. C 2009, 113, 3895–3898.5) K. Prabakar, Hyunwoong Seo, Minkyu Son, Heeje Kim, Materials Chemistry and Physics 2009, 117, 26–28.

Keywords: solar cells, quantum dots, nanocrystals

Figure a)

I-V characterization of CdTe/CdS film sensitized on TiO2


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Figure b)

I-V characterization of CdTeSe film sensitized on TiO2

Abstract:0247

Photosystem I-based biophotovoltaics on nanostructured hematite*

Kasim Ocakoglu1, Joanna Kargul2, Tomasz Krupnik2, Ersan Harputlu1, Saadet Yildirimcan1, Fahrettin Yakuphanoglu3

1Advanced Technology Research & Application Center, Mersin University, Ciftlikkoy Campus, TR-33343 Mersin, Turkey.

2Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096 Warsaw, Poland.3Department of Physics, Faculty of Science, Firat University, TR-23119, Elazig, Turkey.

The conversion of solar energy into chemical energy is one of the most clean, renewable and efficient processes compared to other energy sources such as coal and petroleum. Today, the need to develop inexpensive renewable energy sources is continuing to stimulate scientific research towards more efficient and low cost photovoltaic devices. To this end, we have used photosystem I (PSI) with its inbound light harvesting antenna system as the natural and efficient photosensitizer within the dye-sensitized solar cell (DSSC). PSI is one of the most efficient electron transfer systems, with its quantum efficiency of energy conversion close to 1. The efficient electronic coupling between PSI and two types of semiconductors, TiO2 and hematite, was utilized for engineering of a novel biomimetic DSSC, whereby the n-type semiconductors were deposited on fluorine doped tin oxide (FTO) and anodic aluminum oxide (AAO) templates. We show that PSI provides an efficient self-organized natural photosensitizer and charge separator within the DSSC anodic half-cell, following immobilization of this macromolecular complex over TiO2 or hematite semiconductors. We observed that the PSI-hematite anode was more efficient for solar energy conversion compared to PSI-TiO2. Moreover, application of FTO further improved the efficiency of the biohybrid DSSC compared to the AAO-based system.

*This research has been financially supported by The Scientific and Technological Research Council of Turkey, TUBITAK (Grant: 110M803) and the Polish Ministry of Science and Higher Education (grant no. 844/N-ESF-EuroSolarFuels/10/2011/0 to JK) in the framework of European Science Foundation (ESF-EUROCORES-EuroSolarFuels-10-FP-006).

Keywords: Photosystem I, Fe2O3, hematite, TiO2, biophotovoltaic, nanostructure, solar cell.


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Abstract:0250

Multi-exciton generation in graphene nanostructures

Jülide Yıldırım, Özgür ÇakırDepartment of Physics, Izmir Institude of Technology, İzmir, Turkey

Inverse Auger effect leads to formation of multiple excitons from a single exciton, leading to an enhanced efficiency in conversion of photons to carriers. Inverse Auger effect is the generation of excitons via the nonradiative intraband relaxation of high energy carriers due to Coulomb interaction between the carriers. Inverse Auger effect, which is relatively weak in bulk structures, is enhanced in quantum confined structures due to relaxation of momentum conservation. Bulk neutral graphene has zero bandgap energy, with a linear energy dispersion about the Fermi level. Due to quantum confinement, graphene nanoribbons and graphene flakes develop a bandgap. The emergence of a bandgap makes these structures eligible for solar cell applications. Also due to quantum confinement in graphene nanoribbons and nanoflakes, the momentum conservation is relaxed, and an increase in multiexciton generation rates is expected. A theoretical analysis of inverse Auger Effect is carried out for graphene nanoribbons, and graphene flakes. Tight binding methods are employed to obtain the electronic structure and to calculate the Coulomb matrix elements for the inverse Auger effect. Dipole matrix elements and oscillator strengths are also calculated using the tight binding results.

References:

[1] J. A. McGuire, M. Sykora, J. Joo, J. M. Pietryga, V. I Klimov, Nano Lett. 10, 2049(2010)[2] A. Shabaev, Al. L. Efros, and A. J. Nozik, Nano Lett. 6 2856(2006)[3] N. M. Gabor et al. Science 325, 1367(2009)[4] T. Winzer, E. Malic, Phys. Rev. B Rapid Comm. 85, 241404(R) (2012)

Keywords: Inverse Auger effect, graphene nanoribbons/flakes, oscillator strength, multi-exciton generation,quantum dots

Abstract:0251

Benzotriazole Based Conjugated Polymers for Bulk Heterojunction Organic Solar Cell Applications

Ali Cirpan1, Dogukan Hazar Apaydın2, Gönül Hızalan1, Naime Akbaşoğlu Ünlü1, Levent Toppare1

1Department of Chemistry, Middle East Technical University, 06800 Ankara, Turkey2Department of Polymer Science and Technology, Middle East Technical University, 06800 Ankara, Turkey

Benzotriazole is widely used as an acceptor group in D-A-D type conjugated polymers. Due to ease of processibility in chemical reactions benzotriazole group can be functionalized and tailored according to desired purpose. In these studies tiophene functionalized benzotriazol groups, namely, 4,7-bis(thien-2-yl)2-dodecyl-benzo[1,2,3]triazole (TBT) were copolymerized with fluorene and benzothiadiazol groups via Suzuki Coupling resulting in low band gap alternating conjugated copolymers. Organic solar cell


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devices having a conventional sandwich structure, ITO/PEDOT:PSS/Copolymer:PC60BM /LiF:Al, were constructed and characterized in terms of their solar cell parameters like PCE, Voc, Jsc and IPCE. Among those polymers, TBT and fluorene containing conjugated copolymer was further investigated fort he efficiency improvement studies. In addition, all of the polymers’ hole mobilities were investigated via Space Charge Limited Current method.

Keywords: Organic Solar Cells, Conjugated Polymers, Donor-Acceptor-Donor

Abstract:0252

Thermal annealing effects on the fine structure and performance of P3HT: PCBM based organic solar cells

fabricated in air

Omayma Abdel Aziz Ghazy, Mervat Mohamed Ibrahim, Faten Ismael Abou Elfadl, Eman Mohamed Shehata, Hany Mohamed Moharam, Mohammed Ragaa Balboul

National Ceadiation Research and Technology

Morphology control of the active layer in organic solar cells is essential for efficient energy conversion. The active layers based on (3-hexylthiophene) (P3HT) as an electron donor and the fullerene derivative [6, 6]-phenyl-C61-butyric acid methyl ester (PCBM) as an electron acceptor were fabricated in air. The effect of the annealing at 80 and 140 C on the nanostructure morphology of the active layer and its relation to the solar cell performance was studied. Enhanced absorptions and shifts for the peaks of both P3HT and PCBM upon annealing were found in the UV-visible absorption spectra. The development of crystalline peaks in both the two phases was detected by the x-ray diffraction for the annealed samples. AFM results indicated that a rougher surface was obtained for the higher annealing temperature (140 C). J-V characteristics of the organic solar cells (OSCs) based on the annealed active layers showed an enhanced performance for the sample annealed at 140 C compared to the sample annealed at 80 C with efficiencies of 2.7 % and 0.31 % respectively. The higher efficiency is attributed to improved crystallinty in the two phases..

Keywords: organic solar cell, P3HT, PCBM, annealing

Graphical absract


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Abstract:0254

Design and Production of Small Scale PV Module Laminated By Pressure Method

Muhammet Tahir Güneşer1, Osman Çiçek2, Erzat Erdil1

1Electrical and Electronics Engineering, Karabük University, Karabuk, Turkey2Arac Rafet Vergili Vocational School, Kastamonu University, Kastamonu, Turkey

The principle of the photovoltaic effect is utilized in order to converting solar energy into electricity. Therefore, the most important part of solar energy systems are mostly silicon-based PV modules. Spreading of the use of solar energy is expected with the studies that aimed to increase the efficiency of PV modules lifetime and for their efforts. To obtain PV modules, silicon blocks cut in thin wafers and got the PV cells after managing required electrical contacts. PV cells should be subjected to lamination progress for a long-lasting and efficient. The lamination step is known as most costly phase of the PV module production stages.

In this study, small scaled PV modules are produced to supply the energy to run the traffic signs and signalization devices that use LED technology. It is aimed to design a procedure whereby production of PV modules could be realized under ordinary conditions by persons having no prior technical skill. With this goal, a simple to use, lamination system is designed using the Solidworks software program and produced. The electrical and mechanical parts are organized in such a manner that the lamination process could be effected either by using vacuum or high pressure. Both methods are used in preparing PV modules. Visual inspection and performance of modules prepared by either method showed no significant difference. However, the high pressure method provides an advantage since under ordinary conditions, it is easier to obtain high pressure, even mechanically. The designed lamination system is also light weight and portable.

Keywords: Solar cell, PV module production, laminating systems, laminator

Abstract:0255

New azomethines consisting of thiophene and triphenylamine units for photovoltaic application

Marzena Grucela Zajac1, Jacek Gasiorowski2, Eric Daniel Glowacki2, Dogukan Hazar Apaydin2, Niyazi Serdar Sariciftci2, Ewa Schab Balcerzak1

1Department Of Mathematics Physics And Chemistry, Institute Of Chemistry, University of Silesia, Katowice, Poland

2Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University of Linz, Linz, Austria

The unique combination of properties including high thermal stability, low dielectric constant, high breakdown voltage, good planarization, wear, radiation and chemical resistance, good adhesion properties, low thermal expansion and excellent mechanical properties all make polyazomethines (PAZ) interesting for a variety of applications.1, 2


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Novel polymers for applications in organic electronics were prepared via condensation of thiophene diamine with 4,4’-diformyltriphenylamine and 4,4’,4”-triformyltriphenylamine, respectively. The structures of the resulting polymers are presented in Fig. 1. The chemical structure was confirmed by the 1H-NMR and FTIR spectroscopy.

The thermal stability was evaluated by thermogravimetric analysis (TGA). The obtained polymers exhibited decomposition temperature (Td) around 300°C. The electrochemical behavior was studied by cyclic voltammetry (CV). As calculated from CV, the electrochemical energy band gap (Eg) of these compounds was around 2.8 eV. Optical properties of the prepared polyimines were investigated in solution by UV-Vis and photoluminescence (PL) measurements. In order to assign physical (optical) properties of PAZ thin films, the NIR-Vis-UV spectroscopic ellipsometry (SE) was applied. Using SE the complex dielectric function ( ) as well as complex refractive index ( ) were determined. The devices ITO/PAZ:PCBM/Al were prepared and I-U curves were measured in the dark and under simulated illumination (AM 1.5G, 82 mW/cm2), showing a pronounced photovoltaic effect.

M. Grucela-Zajac is grateful for the financial support of the DoktoRIS project and UPGOW project co-financed by the European Union within the European Social Found.

Keywords: polyazomethines, electrochemystry, photovoltaic

Chemical structure of investigated compound

Abstract:0256

Efficiency and Economical Assessment of South Facing Solar Collectors for Building Applications

Afsin Gungor1, Abdulkadir Kocer2

1Department of Mechanical Engineering, Akdeniz University, Antalya, Turkey2Vocational School of Technical Sciences, Akdeniz University, Antalya, Turkey

Solar energy technologies are renewable and are essential components of a sustainable energy future. However, solar energy technologies are not yet playing the important role they deserve in the reduction of buildings’ fossil energy consumption and consequent greenhouse gas emissions. In this study, efficiency and economical analysis of solar collectors for building applications have been analyzed. These analyses have been performed in view of the optimum tilt angle for the south facing single axis solar collector and its economical criticism. The results show that the optimum tilt angle changed between 1° (June) and 65° (December) throughout year in Antalya, Turkey. This wide period of optimum tilt angle is proved that solar tracking system is an attractive solution to shorten the economical payback period.

Keywords: Solar energy, Alternative energy, Tilt angle

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Abstract:0257

Photovoltaic characteristics of dye sensitized solar cells based on natural dyes

Shenouda Shanda Shenouda Fam1, Eman M Abdou2, Hoda S Hafez3, Madeha Fadel1, Ibrahim S Yahia1, Esam Bakir2, Sabry Abdel Mottaleb2

1Semiconductor and Nano-science Labs, Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt

2Nano-Photochemistry and Solar chemistry Laboratories, Department of Chemistry, Faculty of Science, Ain Shams University, Abbassia, 11566 Cairo, Egypt

3Environmental Studies and Research Institute (ESRI), University of Sadat City, Sadat City, Egypt

In this study, natural dyes such as Black berry and Hibiscus extracted from Berry and Rosella have been employed as light absorbers in dye sensitized solar cell (DSSC). TiO2 nanomaterial was deposited on Florine doped tin-oxide (FTO) substrate to be used as photoanode. Structure of the TiO2 film photoactive electrode was investigated by X-ray diffraction (XRD), diffuse reflectance spectrometer, scanning electron microscope (SEM) and transmission electron microscope (TEM). The effect of illumination intensity on the photovoltaic parameters such as open circuit voltage, short circuit current density, output power, fill factor and efficiency of these cells was investigated in the range 10:100 mW/cm-2. The cell efficiencies were 0.25% and 0.27% for Black berry and Hibiscus, respectively.

Keywords: dye sensitized solar cells-natural dyes

Abstract:0258

Transport Mechanism Studies of eta Solar Cell

Robinson Juma Musembi1, Bernard Odhiambo Aduda1, Julius Mwakondo Mwabora1, Marin Rusu2, Kostantinos Fostiropoulos2, Martha Lux Steiner2

1University of Nairobi2Helmorltz - Zentrum fur Materialen und Energie

Transport mechanism characterization have been carried out on In(OH)xsy modified highly structured TiO2/Pb(OH)xSy/PEDOT:PSS solar cell based on the novel eta concept. Temperature dependent optoelectrical characterization have been perfoermed in the temperature range 200-300K at illumination intensities between 0.05mW/cm2 and 100mW/cm2. The diode ideality factor n under illumination has been found to vary between 1.2 and 1.6, whereas in the dark it ranges 6.9 <n<10.1. the solar cell device has been found to undergo a thermally activated recombination under illumination, while when the device is in the dark, tunneling enhanced recombination process dominates. The solar cell efficiency shows a logarithmic dependence on illumination in the whole temperature range investigated, achieving its maximum at an illumination of approx 45 mW/cm2. A schematic energy band diagram which explains the photoelectrical properties of the device has been proposed to colloborate our results.

Keywords: eta cell, Lead sulphide, PEDOT:PSS


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Abstract:0261

Solar Energy Conversion to Electricity

Steve Biko OmoloEPIXSOLAR

As a self-declared ambassador of solar power in Kenya, my interest centers on Solar Energy Conversion to Electricity using the solar photovoltaic. Epixsolar is a small company that purchases electricity-powered appliances from major distributors, and then supplies them to the solitude regions within Kenya. The prospective customers include the low-income earners. The Company saves Kenyans from paying the huge bills for the Hydro-electric power

Current developments

The use of solar photovoltaic is fast growing, both at the domestic and commercial usage levels. Contemporarily, solar power campaigns and media coverage is fast popularizing the use of solar power. The less-privileged members of the society acknowledge the fact that paraffin prices have become volatile due the unstable global economy. Alongside the BOXX, Epixsolar helps in distributing solar powered gadgets and the solar charging units within Kenya

Energy Policies in Kenya: A major dilemma

Kenya as a republic is currently suffering from the widening gap between energy demand and the energy supply. However, in seeking for a growing economy, the Kenyan Government has encouraged the private sectors to help in developing and marketing the other renewable energy sources such as the solar power. The technology contributes towards satisfying specific individual’s energy demands

Lessons learnt

Kenya has the potential to utilize solar energy; if and only the experts outlay a perfect marketing strategy for the solar powered appliances and the solar charging units. Otherwise, the technology would lie under-utilized, and the low-income lot would not enjoy the affordable Solar technology.

Keywords: SBO

Abstract:0262

The effect of functionalized single wall carbon nanotube on the stability of P3HT-PCBM based bulk heterojunction solar

cells

Gülbeden Cakmak1, Hasan Yüksel Güney1, Süreyya Aydın Yüksel2, Serap Günes2

1Department of Physics, Kocaeli University, Kocaeli, Turkey2Department of Physics, Yildiz Technical University, Istanbul, Turkey

One of the most preferred device structures of organic solar cells is the bulk heterojunction (BHJ) architecture since this architecture leads to higher power conversion efficiencies (PCE) as compared to others [1]. However, there are still some limitations, such as low charge carrier mobility, charge recombination due to limited exciton diffusion length and life time. One way to solve charge transport

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problem in organic solar cells is combining carbon nanotubes with conjugated polymers because of potential advantages of carbon nanotubes such as smaller exciton diffusion lengths and enhanced charge transport. In addition, such devices may be more stable. The stability is also a critical parameter[2,3].

In this study, we investigated the stability effect of the functionalized single wall carbon nanotube (SWNT) as a doping material on BHJ solar cells consisting of poly –(3-hexylthiophene) (P3HT) as a donor material and [6,6] phenyl C61 butyric acid methyl ester (PCBM) as an acceptor material. The PCE of solar cells containing functionalized SWNT and P3HT:PCBM decreased by 3.33 % after 114 days whereas solar cells without SWNT decreased by 20,25 % as compared to the initial measured values.

Study was supported by the Research Found of the Kocaeli University (Project number: 2010/52).

References

[1] S. Gunes,H. Neugebauer, and N. S. Sariciftci, Chem. Rev. 107 (2007) 1324-1338. [2] B. Paci, A. Generosi, D. Bailo, V. Rossi Albertini, R. de Bettignies, Chemical Physics Letters 494 (2010) 69–74.[3] E. Voroshazi, B. Verreet, T. Aernouts, P. Heremans, Solar Energy Materials & Solar Cells 95 (2011) 1303–1307,

Keywords: Carbon nanotube, organic solar cells, stability

Abstract:0263

New Organic Materials For Photovoltaic Application – Aromatic Drugs

Petro Semenovich SmertenkoDepartment of Optoelectronics, V.Lashkaryov Institute of Semiconductor Physics of National Academy of

Sciences of Ukraine

Some novel types of hybrid architectures for solar cell on Si patterned substrates and organic pharmaceutical drugs (PD) have been developed. Water, organic and mixed solvents of thiamine diphosphate hydrochloride (TD), procainamide hydrochloride (PRO), clonidine hydrochloride (CLON), cyanocobolamine (CYCAM), metamizole sodium (MS), laevomycetin (LM) were used for chemical deposition films at room temperature under ambient laboratory conditions. PV performance as function of the PD molecular structure, hybrid morphology, deposition regime and power solar energy has been analysed using SEM, optical microscopy, XRA, FTIR spectroscopy, spectral photoresponse study and PV diagnostics.

“Pharmacotherapy” of n+pp+ Si solar cell by TD, PRO, and MS films deposited has increased its Efficiency up to 18 % in comparing to initial value < 10 %. To realize the organic-inorganic heterostructures thin (10-100 nm) layers of heteroatom aromatic pharmaceutical drugs were deposided from chemical solution on Si patterned surface at the room temperature and the laboratory ambient conditions. The hybrids have shown the solar energy conversation with efficiency of about from 3.7 % up to 8.4 % in dependence on organics, chemical solution media and surface and/or interface morphology. Such hybrid organic-inorganic architecture designs with PD yields a number of advantages: (i) absence of high temperature thermal treatment and high vacuum; (ii) absence of purification and additional doping; (iii) the best use of the solar spectrum due to Si substrate; (iv) use of the low cost and not aggressive organic medium.

Keywords: Aromatic drug, Solar cell, room temperature condition


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Abstract:0265

Optimizing ZnO nanoparticle surface for bulk heterojunction hybrid solar cells

Fengling Zhang1, Shuyan Shao1, Kaibo Zheng2, Tonu Pullerits2, Karel Zidek2, Pavel Chabera2

1Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden2Department of Chemical Physics, Lund University, Lund Swede

The performance of hybrid solar cells composed of polymer and ZnO is mainly hindered by the defects of ZnO. Here, we investigate the effects of ZnO nanoparticle surface modification with poly(ethylene oxide) (PEO) on the performance of bulk heterojunction hybrid solar cells based on poly[2-methoxy-5-(2’-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) and ZnO nanoparticles. The reference device using ZnO nanoparticles as electron acceptor shows an open-circuit voltage (VOC) of 0.83 V, a short-circuit current (JSC) of 3.00 mA/cm2, a fill factor (FF) of 0.46 and a power conversion efficiency (PCE) of 1.15%. After modification with very small amount of PEO, the PCE will be enhanced, which is attributed to less surface traps of ZnO nanoparticles with PEO modification. With optimized PEO (0.05%) modified ZnO nanoparticles as electron acceptors, the device typically shows a VOC of 0.86 V, a JSC of 3.84 mA/cm2, a FF of 0.51 and a PCE of 1.68% due to less recombination loss of carriers, smaller series resistance, and improved the electrical coupling between ZnO nanoparticle and MEH-PPV. However, further increase PEO content to 0.3% will deteriorate device performance.

Keywords: Hybrid solar cells, PEO, ZnO, MEH-PPV

Abstract:0266

Active layers deposited on nanopatterned PEDOT:PSS templates for organic photovoltaic devices

Andrea Radivo1, Endale Tsegaye Mohammed2, Enrico Sovernigo1, Simone Dal Zilio1, Massimo Tormen1, Alessandro Pozzato1

1CNR-IOM, TASC laboratory, LILIT group. Italy2Addis Ababa University. Ethiopia

A promising approach for increasing OPV cells efficiency consists of implementing new cell architectures, controlled at the nanoscale, that optimize light harvesting, exciton splitting and charge collection. Nanoimprint lithography (NIL) represents an excellent candidate for patterning conjugated materials at nanometre resolution, high-throughput and low cost.

This work aims at controlling the morphology of active layers by depositing them either by Physical Vapor Deposition or from solution on high aspect ratio nanostructures made of Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS), patterned by a modified NIL process.

The nanostructures of the PEDOT:PSS film affects the morphology of the active material, that can be deposited sequentially as donor and acceptor layers, or as a single bulk heterojunction layer, filling


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partially or completely planarizing the topography of PEDOT:PSS patterned layer.

By this approach PEDOT:PSS electrodes with a “finger-like” nanoscale features, interdigitated within the active layer are obtained, structure that may favor charge collection and increase light harvesting by trapping effects.

PEDOT:PSS gratings of 80nm linewidth and aspect ratio of up to 5 were produced, resulting also in increased conductivity by up to five order of magnitude, with respect to unstructured films. The PEDOT:PSS structures where filled with different active materials and cells were produced, demonstrating a relative increase of 20% efficiency.

Keywords: PEDOT:PSS, Organic photovoltaics, Nanoimprinting, ligth trapping

Filled PEDOT-PSS line grating.JPG

High aspect ratio PEDOT structure.JPG

Pentacene covered PEDOT-pss lines grating


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Abstract:0269

Power Conversion Efficiency Improvement in Benzotriazole and Fluorene Bearing Conjugated Polymer Based Organic

Solar Cells

Dogukan Hazar Apaydin1, Dilber Esra Yildiz2, Levent Toppare3, Levent Toppare4, Ali Cirpan3, Ali Cirpan4, Ali Cirpan5

1Department of Polymer Science and Technology, Middle East Technical University, 06800 Ankara, Turkey2Department of Physics, Faculty of Arts and Sciences, Hitit University, 19030 Corum, Turkey

3Department of Chemistry, Middle East Technical University, 06800 Ankara, Turkey4The Center for Solar Energy Research and Applications (GUNAM), Middle East Technical University, 06800

Ankara, Turkey5Department of Micro and Nanotechnology, Middle East Technical University, 06800 Ankara, Turkey

In this study, an alternating conjugated copolymer, poly((9,9-dioctylfluorene)-2,7-diyl-(4,7-bis(thien-2-yl)2-dodecyl-benzo[1,2,3]triazole)) (PFTBT), was blended with PCBM (1:1, w/w) and spin coated on ITO substrates. Spin coating speed varied in order to obtain different active layer thicknesses. Solar cell parameters depending on the active layer thickness were investigated. For that matter, organic solar cell devices having ITO/PEDOT:PSS/PFTBT:PC60BM/LiF:Al structure were constructed and J–V characteristics of the constructed devices were investigated both in dark and under simulated illumination (AM 1.5G, 100 mW/cm2). The power conversion efficiency (PCE) of the devices was varied according to active layer thickness and the best power conversion efficiency was recorded as 1.06%. Furthermore, the incident-photon-to-current-efficiency (IPCE) measurements were carried out and the best efficiency was found to be 51%.

Keywords: Benzotriazole, organic solar cell, thickness dependent efficiency

Abstract:0270

Optical characterization of PVK/ZnSe hybrid nanocomposites for photovoltaic application

Aida Ben Chaaabne1, Ziad Ben Hamed1, Mohamed Abderahmane Sanroury2, Fayçal Kouki1, Andreas Zeinert3, Habib Bouchriha1

1Laboratory of Advanced Materials And Quantum Phenomena, Department of Physics, Faculty of Sciences of Tunis, 2092 El-Manar I, Tunis, Tunisia

2Laboratory of Structural Organic Chemistry: Synthesis And Physico-Chemical Studies, Department of Chemistry, Faculty Of Sciences Tunis, 2092 El-Manar I, Tunis, Tunisia

3Laboratory of Physics of Condensed Materials, University of Picardie Jules Verne, 33 Rue St. Leu, 80039, Amiens, France

Polymer/inorganic nanocomposites have attracted much attention due to their low cost, substrate flexibility [1], ease of processing [2] and size tunable absorption-emission properties. For the polymer component, poly(N-vinylcarbazole) (PVK) is a good hole transporting material in photovoltaics [3]. It has been mixed with inorganic compounds to achieve good conductivity [4] for new promising


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optoelectronic devices. In this work, optical properties of hybrid organic/inorganic PVK/ZnSe layers are investigated as a function of the nanoparticle volume fraction using the effective medium model (EMM). The layers are deposited by spin coating technique on glass substrate and their transmission and reflection spectra were performed in the range 200-800nm. Optical constants such as reflection index n and extinction coefficient k are extracted and injected in the EMM formula to determine dielectric permittivity and absorption coefficient. The optical band gap of the hybrid structure was also obtained as a function of nanoparticle volume fraction. The results show an increase of the conductivity after ZnSe doping (6.6 10-11Ω-1.cm-1), depending on ZnSe concentration. Structural characterisation of the PVK/ZnSe nano-composite films was carried out using scanning electron microscopic.

References:

[1] C. Kastner,S. Rathgeber,D. A. M. Egbeand H. Hoppe, J. Mater. Chem. A, 2013, 1, 3961–3969[2] M.C. Scharber N.S. Sariciftci, Efficiency of Bulk-Heterojunction Organic Solar Cells, Progress in Polymer Science (2013)[3] G. Kaune, W. Wang, E. Metwalli, M. Ruderer, R. Roßner, S.V. Roth, and P. M¨uller-Buschbaum,Eur. Phys. J. E 26, 73–79 (2008).[4] A.J. Heeger, N.S. Sariciftci, E.B. Namdas, Semiconducting and Metallic Polymers,Oxford University Press, 2010. 978-0-19-852864-7

Keywords: Optical properties; Nanocomposite films;PVK;ZnSe nanoparticles;Energy band gap

Abstract:0271

Phenanthroimidazole-based derivatives as potential charge transporting materials for photovoltaics

Ramunas Lygaitis, Rita Butkute, Juozas Vidas GrazuleviciusFaculty of Chemical Technology, Kaunas University of Technology, Kaunas, LT 50254, Lithuania

Phenanthroimidazole derivatives are recognized as efficient emissive or charge transporting materials for various organic electronics applications. Here we report on the synthesis and properties of new 2,7- and 3,6-substituted phenanthroimidazole-based derivatives (Scheme 1). The phenanthroimidazole core was modified attaching carbazole and diphenylamine moieties using Cu and Pd-catalysed chemistry. The thermal, optical, photophysical, electrochemical and photoelectrical properties were investigated. The hole mobility of 0.001 cm2/Vs was determined by time-of-light technique in the layer of one of the compounds. The ionisation potential was determined by means of cyclic voltammetry and it ranges from 4.96 eV to 5.52 eV. The investigation showed that the synthesised compounds are potential semiconducting materials which could be used in various fields of organic electronics. Compounds possessing low ionisation potentials and high hole mobilities could be used as hole transporting layers for dye sensitised solar cells application.

Keywords: phenanthroimidazole, glass transition, hole transport, ionisation potential


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The structures of the synthesised compounds

Abstract:0272

Evaluation of high efficient silicon solar cells with mono-crystalline silicon absorber and the impact of high energy particle damage by electroluminescence measurements

Heinz Christoph Neitzert1, Giovanni Landi2, Kai Broszio3, Frank Wünsch4, Marinus Kunst5

1Dept. of Industrial Engineering (DIIn), Salerno University, Fisciano, Italy2Faculty of Mathematics and Computer Science, FernUniversität Hagen, Germany

3Faculty of Electrical Engineering and Computer Science, TU Berlin, Germany4 Roth & Rau, Hohenstein-Ernstthal, Germany

5Institute for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin, Germany

We characterized solar cells from different provenience and with different structure, but all with a mono-crystalline silicon absorber layer, using electroluminescence measurements under forward bias conditions. The investigated solar cells comprised classical pn-homojunctions, either with classical contact configuration or with interdigitated back contact configuration, and also amorphous silicon on crystalline silicon heterojunctions. The observed electroluminescence signal around 1150nm is due to silicon band-to-band recombination. We measured the spectral distribution and extracted as parameters the peak wavelength, the overall peak emission intensity, the peak amplitude and the FWHM value. A very good correlation between emission intensity and solar cell efficiency has been found, even using very different device structures.

One type of the investigated solar cells - namely the high efficiency conventional pn-solar cells has subsequently been subjected to a degradation induced by the irradiation with protons at an energy of 0.5MeV and different fluences up to a maximum value of 5x10^5 protons/cm^2. The projected range of the protons in Silicon, as calculated by TRIM simulation, at this energy is about 7um. This means, that the damaged region is relatively close to the solar cell surface and concentrated in the pn-junction region. The quenching of the electroluminescence is shown to be a good measure for the evaluation of the irradiation damage. The fluence dependence of the degradation of the solar cell efficiency and of


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the the EL intensity are directly correlated. Additionally we measured also the effective excess charge carrier lifetime degradation after irradiation on reference samples by the contactless TRMC-technique.

Keywords: crystalline silicon solar cell, electroluminescence, proton irradiation, TRMC measurements

Figure 1

High efficiency pn-Silicon homojunction solar cell degradation as a function of proton fluence

Figure 2

Correlation between the change in the differential luminescence efficiency and the change in the solar cell efficiency for a high efficiency pn-Silicon homojunction cell irradiated with different fluences of 0.5MeV protons

Figure 3

TRMC transients for Si wafers before and after irradiation with different fluences of 0.5MeV protons


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Abstract:0275

Effect of Singlewall Carbon Nanotube and TiO2 layer Addition on the Performance of P3HT:PCBM Based Organıc Solar Cells

Adem Yar, Okan Demir, Ahmet AvcıDepartment of Mechanical Engineering,Selçuk University,Konya,Turkey

In this study organic solars cells of which active layers were introduced 0,025 % (wt) multiwall carbon nanotube were produced in ambient atmosphere and the effect of carbon nanotube on the cell performance was investigated. Cell layers were coated via spin coating method and were annealed at certain temperatures. Morphological characterization of the produced solar cells were carried out by Scanning Electron Microscope and Atomic Force Microscope, and the optical characterization was carried out by absorbance measurements. By addition of carbon nanotube to the active layer increase in current density, efficiency and fill factor were observed. Further, absorbance analyses showed that coating the active layer in ambient atmosphere caused cells to degrade. Additionally, sol-gel TiO2 was coated onto the active layer and its effects on the cell performance were investigated.

Keywords: Organic solar cells, P3HT:PCBM, Single wall carbon nanotube, TiO2

Effect of SWCNT addition on the I-V characteristics of the solar cell

Abstract:0276

Optimizing the electrodeposition parameters of SnS thin film from non-aqueous solution for CdS/SnS solar cells

Shaimaa Abdullah Elyamny1, Marwa Fathy Bahnasy1, Abd El Hady Bashir Kashyout1, Ahmed Adel Beshara2, Gamal Daniel Roston2

1Electronic Materials Research Department, Advanced Technology and New Materials Research Institute, City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, P.O. Box

21934, Alexandria, Egypt2Department of Physics, Faculty of Science, Alexandria University.

SnS thin film was electrodeposited on CdS/ITO/glass substrate from non-aqueous solution at room temperature. Electrodeposition is used because it is a simple and economically viable technique, which produces films of good quality for device applications. The deposition bath consists of 0.2 M of DL-Tartaric acid saturated with sulfur and 0.02-0.06 M from anhydrous SnCl2 dissolved in ethylene


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glycol. SnS film was deposited galvano-statically at a current density range of 0.5-2 mA/cm² for 5-30 min. Structural, morphological, elemental and optical analyses were studied for as-deposited and heat treated films using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and UV-Vis spectrophotometer, respectively. For fabricated ITO/CdS/SnS solar cells, Capacitance–voltage and Current-voltage were measured under dark and illuminated conditions.

Keywords: Electrodeposition, non-aqueous, CdS/SnS solar cell

Abstract:0279

A Simple Lamination Unit to Manufacture Small Scale Modules

Mustafa Gökdağ, Muhammet Tahir Güneşer, Erzat ErdilDepartment of Electrical-Electronics Engineering, Karabuk University, Karabuk, Turkey

Small-scale solar modules have large area of applications from traffic hazard lights to charging portable devices. The importances of small modules are that they are cost effective, light weight, easily portable, less space and easy to use etc. In photovoltaic module production the encapsulation method between glass and tedlar using the ethylene vinyl acetate as a pottant is still most known and standard method in industry. This method requires a special lamination device. A simple lamination unit may be used in producing small-scale modules giving the developing countries a chance to increase their productions and to decrease unemployment, and also to use environment friendly energy. In this study a lamination device which is able to produce up to 10 Wp PV modules were designed. PV modules were successfully laminated and produced using the device. Heat cool cycle was made faster and more modules can be manufactured within unit time. Shifting of cells inside the sandwich was prevented using a simple technique. The design of casting allows vacuum pump to easily get air and waste gas outside. A PID temperature controller unit with J-type thermocouple whose sensing terminal lies toward to inside of casting was used to control the temperature of casting according to the process requirements. An example application with manufactured module was done and some measurements were taken to test the module.

Keywords: Solar Module Lamination, Module Production, Charging portable devices with solar energy

Lamination device


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Produced module

Abstract:0281

Effect of Active Layer Thickness on Solar Cell Parameters and Mobility

Gönül Hızalan1,3, Hande Ünay2, Naime Akbaşoğlu Ünlü1, Ali Cırpan1,2,3, Levent Toppare1,2,3,4

1Department of Chemistry, Middle East Technical University, 06800 Ankara, Turkey2Department of Polymer Science and Technology, Middle East Technical University, 06800 Ankara, Turkey

3The Center for Solar Energy Research and Application (GÜNAM), Middle East Technical University, 06800 Ankara, Turkey

4Department of Biotechnology, Middle East Technical University, 06800 Ankara, Turkey

The reasons behind the increasing interest in organic solar cells can be summarized as; polymers offer fast, simple processing, low cost and large volume processing. In addition to these, optical and electronic properties of the polymers can be tuned easily via chemical modifications. Polymers are good chromophores that have high absorption coefficients, about 10e5 1/cm. The absorption spectrum of the active layer must match with the solar spectrum and the active layer must be sufficiently thick for efficient collection of photons. At first glance, decreasing the band gap of the polymer and increasing the active layer thickness seem like to lead to high efficiencies. However, they lead to lowering of Voc and burdening the charge transport, respectively.

Here, we report the fabrication and characterization of solar cells using the polymer, poly (2-(2-octyldodecyl)-4-(selenophen-2-yl)-7-(5-(thiophen-2-yl)selenophen-2-yl)-2H benzo[d][1,2,3] triazole) in bulk heterojunction with the fullerene derivative (PC60BM). The characterizations are carried out under illumination of AM 1.5 G. Polymer –PC60BM blends are spin coated with different active layer thicknesses to investigate the effect of thickness on solar cell parameters and hole mobility.

Keywords: Organic solar cells, Active Layer Thickness, Hole Mobility

Structure of the polymer


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Abstract:0283

Patterned Semiconductor Nanocrystals by Using Block Copolymers and Their Application in Hybrid Solar Cell Devices

Sumeyra Buyukcelebi1, Mahmut Kus2, Aysenur Erdogan1, Mustafa Ersoz1

1Department of Chemistry, Selcuk University, Konya, Turkey2Department of Chemical Engineering, Selcuk University, Konya, Turkey

Films of block copolymers have been recognized for the preparation of various functional nanostructures, which may be used in surface nano patterning, lithography, and templating for the fabrication of organic-inorganic electronic, optical, and magnetic devices [1]. Among various lithographic technologies, the patterning method using a self-assembled block copolymer has advantages of size control and low cost over other methods [2]. Such nanopatterns supply optimum contact area at p-n junction interface and lead to increase in performance. On the other hand, BCPs are promising materials also for large area printed electronics [3].

In this study, We investigated the phase separation in BCP-nanocrystal blends to obtain comb-like structure for optimum p-n junction area. Oleic acid capped CdSe nanocrystals were mixed with poly (styrene-b-methylmethacrylate) (PS-b-PMMA) block copolymers, then spin casted on ITO coated glasses. Microphase separation was observed after thermal annealing the films. After completing the phase separation, Ar/O2 plasma was used to remove PS and PMMA block to obtain nanocrystal blocks on ITO surface. AFM results showed that, nanocrystal block can be obtained with this procces. Figure 1 shows the theory of this work. AFM images were given in figure 2. Finally, CdSe-P3HT polymer hybrid solar cells were fabricated and characterized to compare the efficiencies of patterned and nonpatterned devices.

Keywords: block copolymers (PS-b-PMMA), hybrid solar cells, microphase separation, nanocrystals (CdSe), nanopattern

Figure 1. Schematic wiev of the theory of study

Figure 2. AFM images of films patterned of PS-b-PMMA/CdSe mixtures


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Abstract:0285

Use of Spiro Alkylated Fluorenes in Weak Donor-Strong Acceptor Type Polymers for Organic Photovoltaics

Applications

Serafettin Demic1, Hakan Bilgili2, Deniz Aykut Ergün2, Ceylan Zafer2, Sermet Koyuncu3

1İzmir Katip Çelebi University, Izmir, Turkey2Ege University Solar Energy Institute, Izmir, Turkey

3Çanakkale On Sekiz Mart University, Çanakkale, Turkey

Organic photovoltaics is an alternative choise of renewable energy. Achieving significant improvements in processing and manufacturing would push it a relative alternative to silicon based photovoltaics [1]. Conjugated polymers are promising materials interms of many aspects (electronic properties, low cost, versatility, thin film&flexibility, easy processing) [2]. To achieve high power conversion efficiency (PCE) in photovoltaic applications, electron donor and acceptor moieties should be chosen carefully. For an ideal polymer, a weak electron-donating unit conjugated to a strong electron-withdrawing unit should simultaneously decrease the HOMO energy level and the band gap of the D/A polymer and therefore to increase Voc and Jsc of the device [3].

It is well documented that BHJ devices fabricated using P3HT and PCBM give PCE of about 5% [4]. There are several groups worldwide working on novel low bandgap donor polymers to enhance PCE further up to 10% using PCBM as acceptor [5].

In this study, we present three new donor-acceptor type co-polymers based on fluorene (spirofluorene/octylfluorene) and benzothiadiazole/benzoselenadiazole to be used as donor material in BHJ type organic photovoltaic cells while the PC71BM is used as the acceptor. The highest PCE of the cells fabricated from the polymers FC12DTBT as 3.76% while the standard cell with polymer-F8DTBT gave an efficiency of 3.47% (under AM 1.5 condition).

References

1) J. MingJiang, M. Yuan, K. Dinakaran, A. Hariharanand, J. Mater. Chem. A,2013,1,4415.2) TM. Clarkeand, J. Durrant, Chem. Rev. 2010,110,6736–6767.3) JM. Jiang, MC. Yuan, K. Dinakaran, A. Hariharanand, KH. WeiJ. Mater.Chem. A, 2013,1,4415.5)http://www.konarka.com/index.php/site/pressreleasedetail/konarkas_power_plastic_achieves_world_record_83_efficiency_certification_fr

Keywords: Solar Cells, spiroalkyl, fluorene, donor-acceptor type polymers


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Abstract:0286

Incorporation of Conjugated Polyelectrolytes in Organic Solar Cells

Cigdem YumusakDepartment of Physics, Faculty of Arts and Sciences, Yildiz Technical University, Istanbul, Turkey

Mixed ionic/electronic conduction in conducting polymers introduces new physics/chemistry and an additional functionality in organic optoelectronic devices. These materials combine the optical and electrical qualities of conjugated polymers with the properties of polyelectrolytes can be modified by electrostatic interactions. The incorporation of an ionic species in a conjugated polymer matrix results in the increase in electrical conductivity associated with the electrochemical doping of the material. The conductivity increase in these materials arises from the introduction of charged polaronic species on the polymer backbone, which is charge-compensated by a counterion. Here we present the role of ionic charge carriers in the active layers of organic field effect transistors, organic light emitting diodes and organic solar cells.

Keywords: organic solar cells, conjugated polyelectrolytes, organic optoelectronics, doping of conducting polymers, electrochemical doping

Abstract:0289

Comparison between Synthesis Techniques to obtain ZnO Nanorods and its Effect on Dye Sensitized Solar Cells

Sule Erten Ela, Alisah Cagatay CakirEge University, Solar Energy Institute, 35100, Bornova-Izmir, TURKEY

Among environment-friendly and renewable energy sources, dye sensitized solar cells have always been high on the list of likely candidates [1]. As one of the most important oxide semiconductor materials, ZnO has attracted considerable attention due to its good optical, electrical, and piezoelectrical properties [2].

This study reports reproducible, low-temperature solution-based process for the preparation of crystalline ZnO nanorods. Also, ZnO nanorod structured dye sensitized solar cells using ruthenium dye (Z907) have been fabricated and characterized. The formation and growth of zinc oxide nanorods are successfully achieved. We analyzed three different synthesis method using solution phase method, autoclave and microwave. Analysis of ZnO nanorods shows that calcination at lower temperature is resulted in a nanorod growth. Well-aligned ZnO nanorods are obtained with the length of 330-558 nm and diameters of 14-36 nm. The XRD, SEM, and PL spectra have been provided for the characterization of ZnO nanorods. Microwave-assisted ZnO nanostructured dye sensitized solar cell devices yielded a short-circuit photocurrent density of 6.60 mA/cm2, an open-circuit voltage of 600 mV, and a fill factor of 0.59, corresponding to an overall conversion efficiency of 2.35 % under standard AM 1.5 sun light


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References[1] (a) B. O’regan, M. Gratzel, Nature, 353 (1991) 737. (b) Hagfeldt A, Gratzel M, Acc. Chem. Res., 33 (2000) 269[2] a)S. Erten-Ela, M.D. Yilmaz, B. Icli, Y. Dede., S. Icli, and E.U. Akkaya, Organic Letters, 10 (2008) 3299, b) A. Cagatay Cakir, Sule Erten-Ela, Advanced Powder Technology, Vol. 23, Issue 5, pp. 655-660, 2012.

Keywords: dye sensitized solar cell, nanocrystalline materials, nanostructured zinc oxide, X-ray diffraction (XRD), scanning electron microscopy (SEM)

Fig. 1. Schematic drawing of dye sensitized solar cell

Abstract:0290

Photovoltaic Characterizations of CdO nanoparticles, ZnO nanorods and ZnO:CdO nanocomposites in Dye Sensitized

Solar Cells

Hizir Sarica, Sule Erten ElaEge University, Solar Energy Institute, 35100, Bornova-Izmir, TURKEY

Energy is currently the most important problem facing mankind. In recent years, transparent conductive oxides (TCOs) have attracted much attention owing to their potential applications in electronics and photovoltaic devices [1]. ZnO and CdO is one of the most important TCO materials and it is an n-type semiconductor [2].

In this study, nano-CdO materials and nanorod ZnO materials are prepared using hydrothermal methods. Different types of nano-CdO materials and ZnO nanorod materials are obtained. Different morphologies of nanomaterials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) measurements. Dye sensitized solar cells have been fabricated and characterized to test the efficiencies of nano-CdO, nanorod ZnO and ZnO:CdO nanocomposite materials using organic and organometalic dyes.

References[1] (a) B. Oregan, M. Gratzel, Nature, 353 (1991) 737. (b) Hagfeldt A, Gratzel M, Acc. Chem. Res., 33 (2000) 269[2] a) S. Erten-Ela, S. Cogal, S. Icli, Inorganica Chimica Acta, 362 (2009) 1855.


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b) A. Cagatay Cakir, Sule Erten-Ela, Advanced Powder Technology, Vol. 23, Issue 5, pp. 655-660, 2012.

Keywords: Dye Sensitized Solar Cell, Nano-CdO, nanorod ZnO, ZnO:CdO composite, SEM, AFM

Fig. 1. Schematic Drawing of DSSC

Abstract:0291

Study of the electrical and structural properties of thin layers of amorphous silicon deposited by PECVD on porous silicon

metallized

Sonia Ben Slama, Masseoud Hajji, Hatem EzzaouiaTechnopole Borj Cedria

The aim of this work is studying electrical and structral properties of amorphous silicon layers.Porous silicon were elaborated by the elactrochemical method,the metallization of porous silicon was carried out by immersion of substrates in solution of nickel.Amorphous silicon thin films were deposited by PECVD.

Keywords: properties layers nickel porous silicon


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Abstract:0293

Effect of etching parameters on morphology and optical properties of porous nanowire silicon obtained by metal

assisted Vapor phase etching method

Ouertani Rachid, Amri Chohdi, Hamdi Abderrahman, Salma Aouida Aouida, Khalifa Marouen, Bouaicha Mongi, Bessais Brahim, Ezzaouia Hatem

Photovoltaic Laboratory Research and Technology Centre of Energy, Borj-Cedria Science and Technology Park, BP 95, 2050 Hammam-Lif, Tunisia.

On the basis of vapor etching (VE) technique and metal assisted electroless etching techniques, we cmbine, in this work, these two techniques to obtain porous silicon nanowires (PSiNWs). Firstly, the metal nanoparticles were deposited on P-type silicon wafers.Secondly, the SiNW arrays were formed by exposing the wafers to the vapor of HF- H2O2 or HF- HNO3. Better results have been obtained with silver and H2O2 as reducting metal and oxidizing agent, repectivily. The HF concentration of the etching solutions is maintained constant, while the H2O2 concentrations vary from 0.1 to 0.5 M. The etching times vary from 20 to 120 min, respectively. H2O2 concentration is the key factor of the porosity varieties, while the etching time could increase the thickness of the porous layer and the wire lengh.

MEB images of the etched samples show uniform distribution of the grown SiNWs on the whole wafers and their direction is not always vertical to the substrate surface direction. MEB caracterization reveals that SiNWs are not vertical but curl and intertwine with lengths starting from 0,5 to 5 µm with an average diameters of 100 to 50 nm. For relatively high concentration of H2O2, the tips of the nanowires congregate together.

PL spectrum and the FTIR analysis confirm that the surface of the HF-treated porous SiNWs are composed of Si–Hx and Si–O bonds. The emission intensity from the local porous structure quickly enhances with the porosity. The PL schift is explained by contribution of the SiO2 and the quantum confinment effect.

Keywords: porous Silicon, Silicon nanowire, electroless etching, metal assisted, PL, FTIR


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Abstract:0294

Adaptation and Evaluation of a Small Scale Solar Dryer

Adewale Sunday Mofolasayo1, Azuka Henry Otuonye2, Busayo Solomon Famuyiwa4, Aderonke Taiwo Yahaya4, Richard O. Igbinadolor1, John Olusegun Ojediran3

1End Uses Research Department, Cocoa Research Institute of Nigeria, Ibadan, Nigeria2Crop Protection Division, Cocoa Research Institute of Nigeria, Ibadan Nigeria

3Department of Agricultural Engineering, Landmark University, Omu Aran, Nigeria4Department of Farming Systems and Extension Research, Cocoa Research Institute of Nigeria

The erratic weather conditions occasioned by climate change has triggered extreme meteorological conditions such as excessive rain causing prolonged humid conditions which is unfavourable to cocoa drying. Poorly dried cocoa beans is the major cause of mould growth which produces toxin such as Ochratoxin A which lead to a low premium paid for such bean or total rejection where tolerable limit is exceeded. The use of alternatives such as wood or fossil fuel fired artificial dryers often generates quality problems in addition to high operating costs. Consequently, a small scale solar dryer was constructed to facilitate drying during humid conditions. The dryer has an overall dimension 5070 x 1800 x 1600 mm length, breadth and height respectively. The drying bed measured 2 x 1.6 x 0.03 m length breadth and depth respectively. The dryer has the capacity to dry 100 kg fresh cocoa beans per batch. The roof material was transparent polyethylene sheet which protect the drying beans during rain. Two collector wings which spanned the north-south direction had 4 inch hardcore materials embedded. The hardcore was coated black to trap solar radiation during the day and release heat during the cool period of the night.

Preliminary evaluation of the dryer showed the bean dried to safe moisture level of 8% within 7 days. Visual examination showed no development of fungi. Cut test revealed a high brown bean percentage. The dryer reduced labour required to cover or pack the beans during rain.

Keywords: solar dryer, cocoa, climate change, acidity

Abstract:0296

Enhancement of natural convection in an asymmetrically heated vertical channel by an adiabatic auxiliary plate

Hatem Laatar1, Soumaya Taieb2, Jalloul Balti1

1Département de Physique, Faculté des Sciences de Bizerte, University of Carthage, 7021 Jarzouna, Tunisia2LETTM, Département de Physique, Faculté des Sciences de Tunis, Tunis El Manar University, 1060 Tunis, Tunisia

The effect of an auxiliary plate on natural convection in an asymmetrically heated channel is studied numerically in laminar regime. The computational procedure is made by solving the unsteady two dimensional Navier-Stokes and energy equations. This nonlinear system is integrated by a finite volume approach and then solved in time using the projection method, allowing the decoupling pressure from velocity. More than hundred simulations are performed to determine the best positions of the auxiliary plate that enhance the induced mass flow and the heat transfer rate for modified Rayleigh numbers


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ranging from Ram=102 (1.E2) to Ram=105 (1.E5). Contour maps are plotted and then used to precise the enhancement rates of the mass flow and the heat transfer for any position of the auxiliary plate in the channel. The numerical results (velocity, pressure and temperature fields) provide detailed information about the evolution of the flow structure according to the geometric configurations studied. In addition, they permit to explain why the mass flow rate and Nusselt number are enhanced for certain positions of the auxiliary plate and are on the contrary deteriorated for others.

Keywords: vertical channel, auxiliary plate, mass flow rate, Nusselt number, heat transfer enhancement, numerical simulation.

Abstract:0297

Multi-electron transfer systems for solar energy storage

Sherine O Obare, Liyana A. Wajira Ariyadasa, Clara P AdamsDepartment of Chemistry, Western Michigan University

Nanoscale metallic particles are of great interest due to their importance in advanced technological applications. Synthetic procedures that produce gram-scale, well defined and monodisperse metallic nanoparticles with controlled size and shape, especially within the 1-4 nm size range is a continuing challenge in nanoscale science. We have developed new organic ligands that when used as stabilizers for metal nanoparticles, provide the ability to gain control of the particle size in one-step synthetic procedures. Monodisperse metallic nanoparticles were synthesized and characterized using spectroscopic, microscopic and x-ray techniques. We have further investigated the electrochemical quantized double-layer (QDL) charging differences of 1-4 nm metallic nanoparticles. Within this size range, the electronic properties transition from a bulk-like continuum of electronic states to molecule-like, discrete electronic orbital levels. Such properties have led us to investigate their charging and discharging at large band-gap semiconductor interfaces. The results are paramount toward understanding and developing advanced materials for solar energy storage. We demonstrate the efficiency of the semiconductor/metal nanoparticle interfaces for the storage of solar energy and for using this energy as needed, specifically, in the various chemical reactions.

Keywords: Nanoscale materials, electron storage, size-control, solar energy


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Abstract:0298

Preparation and Physical Properties of Polymer for Photovoltai Applications

Abdelqader Ibrahim Imragaa1, Ahmed Iraqi2

1Abdelqader Imragaa, benghazi university, Benghazi, Libya2Ahmed Iraqi, University of Sheffield, Sheffield S3 7HF, UK

Polymer bulk heterojunction solar cells based on composites of electron-donating conjugated polymers and electron accepting molecules such as fullerenes, offer promise for the realisation of printable, portable and flexible photovoltaic devices with relatively low cost.

In recent years, organic solar cells utilizing conjugated polymers have attracted widespread interest. These polymers are promising in terms of their electronic properties, low cost, versatility of functionalization, thin film flexibility, and ease of processing. These factors indicate that organic solar cells, although currently producing relatively low power conversion efficiencies (~7%) 1-3 compared to inorganic solar cells, have the potential to compete effectively with alternative solar cell technologies. However, in order for this to be feasible, the efficiencies of organic solar cells need further improvement. This is the focus of extensive studies worldwide.

In this contribution, we report the preparation and characterisation of low band-gap semiconducting materials consisting of donor/acceptor type alternating copolymers of 2,7-linked carbazole units with bithiophene repeat units and 5,7-bis(5-bromothiophen-2-yl)-2,3-bis(4-(2-ethylhexyloxy) phenyl) thieno[3,4-b]pyrazine repeat units. The optical and electrochemical properties of these polymers are presented.

Keywords: Electroactive polymers, synthesis of novel polymers and functional materials, electroluminescence, solar cells

Abstract:0299

Density Functional Theory studies of spacer effect in Donor-Acceptor copolymer for organic solar cell

Azazi Amel, Mabrouk Ali, Alimi KamelDepartment of physics, Monastir University, Monastir, Tunisia

In this study, new low band gap copolymers are theoretically investigated on the basis of quantum chemical simulation. We use density functional theory (DFT) to elucidate the photophysical properties of some new copolymer for solar cells applications where the key design rules to achieve a high quantum-efficiency and high open-circuit voltage.

These theoretical methods and calculation techniques not only promote deeper understanding of the connection between chemical structures and the photophysical properties of the donor–acceptor system but also can be used to rational design novel donor–acceptor system. The effects of spacer unit, as vinylene and ethynylene groups, on their structural, optical, electronic, charge transporting, and photovoltaic properties were investigated. These groups play an important role in terms, planarity,


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band gap, and interchain packing, as well as for the performance of the resulting the bulk heterojunction (BHJ) structure solar cells. Then, the energy diagram of the organic active layer at the metallic contact is presented.

This study gives a pathway for further improving the efficiency of heterojunction solar cells and indicates a novel concept for developing new active layer materials.

Keywords: Low band gap, charge transfer, DFT, solar cells, energy diagram.

Abstract:0300

New carbazole-PCBM bulk heterojunction based materials for organic solar cells

Najah Bouzayen, Boubaker Zaidi, Kamel AlimiUniversity of Monastir, Research Unit: New Materials and Electronic Organic Devices UR11ES55, Faculty of

Sciences of Monastir, Monastir 5000, Tunisia

Recently, organic solar cells (OSCs) have shown very promising performances in optoelectronic applications due to their potential to deliver low cost devices. However, one of the major problems of OSCs is the lower PCE and smaller photocurrent than that of silicon based solar cell which can be resolved by the development of novel materials that can enhance the matching of absorption spectra with the solar spectrum. Considerable attentions have been paid for the development of new materials and morphological structures in order to enhance device performance and indeed impressive PCE of 6-8%. Such structures have been elaborated with low bang gap polymers as electron donor and fullerene derivatives as electron acceptor of a single bulk hetero-junction (BHJ) active layer, in which the electron donor and electron acceptor (fullerene derivative) was deposited from a common solvent. Nanostructured films based on low band gap donor-acceptor (D-A) small molecules with carbazole and benzothiazole as electron donor units and (6,6)-phenyl- C60- butyric acid methyl ester (PCBM) as electron acceptor, were fabricated and characterized before being used as an active layer in a bulk heterojunction photovoltaic device. The photon absorption and the quenching properties of the excited electrons were observed through ultraviolet and photoluminescence (UV, PL) spectroscopies. Then, the photoinduced electron transfer process involved by the two materials, with different ionization potential and electron affinity enhanced the power conversion efficiency of the solar device.

Keywords: Bulk heterojunction, small molecules, carbazole, PCBM, organic solar cells.

Carbazole derivative PCBM


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Abstract:0301

Hierarchical ZnO nanostructure based solid-state dye-sensitized solar cell

Zoltán Szabó, Eszter Fülöp, Róbert Erdélyi, János VolkDepartment of Nanocomposites, MTA TTK MFA, Budapest, Hungary

High aspect ratio ZnO nanowires are thought to be a potential candidate for next generation dye-sensitized solar cells (DSSC) because they can ensure a high electron mobility direct pathway to the anode of the photovoltaic cell. However, in order to attain an efficient light absorption by the chemisorbed dye molecules the roughness factor of the nanowire array has to be increased dramatically. We report a novel low temperature, wet chemical fabrication route for high specific surface “cactus-like” hierarchical ZnO nanostructure which based on a regular array of thick (250-350 nm) vertical pillars and thin (20-30 nm) horizontally grown secondary nanowires which ensure the enhanced specific surface. The hexagonal seed pattern for the regular nanopillar arrays was fabricated in photoresist layer by nanosphere photolithography using self assembled polystyrene nanosphere “lenses”. The aqueous chemical growth of the nanopillars is followed by a conformal deposition of ZnO nanocrytal seeds and a second wet chemical growth step. The randomly grown nanowire, the regularly ordered pillars and the different hierarchical ZnO structures based cells were compared by measuring the quantity of the adsorbed dye molecules and by the I-V measurements. The higher specific surface area of the hierarchical structures bound more dye molecules causing higher short circuit current. Better photovoltaic performances were achieved by optimizing the spiro-OMeTAD concentration and spin coating parameters to obtain more efficient infiltrating and covering properties.

Keywords: DSSC, aqueous chemical growth, ZnO, hierarchical nanostructure, spiro-OMeTAD, solid state

Cactus-like ZnO nanostructure


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Abstract:0303

Studying the effect of hydrothermal temperature on the properties of TiO2 nanotubes

Hesham Ali Hamad, Marwa Fathy Ibrahim, Abd El Hady Bashir KashyoutAdvanced Technology and New Materials Research Institute (ATNMRI), City of Scientific Research and

Technological Applications (SRTA-City)

TiO2 nanotubes have been prepared by a simple hydrothermal method from anatase TiO2 nanoparticles. Influences of the different hydrothermal temperatures on the TiO2 nanotubes properties were investigated. Micro-structural and morphological properties of the TiO2 nanotube powders were carefully characterized. Results indicate that anatase TiO2 nanotubes with high aspect ratio (Outer diameter 4 nm and length 50 nm), perfect tubular architecture, and smooth surface were successfuly synthesized at 140 °C for 48 hrs. A dye-sensitized solar cell (DSSC) was then assembled as ITO glass/[TiO2-nanotube (N3 dye)]/I2 + LiI electrolyte/Pt/ITO glass. An ultimate photovoltaic efficiency 4.3% (active area 1 cm2) at 100 mWcm-2 (Xe(Hg) lamp) of the assembled DSSC device can be obtained for the TiO2-nanotube annealed at 450 °C for 30 min.

Keywords: DSSCs, TiO2 nanotubes, hydrothermal, Electron Microscope

Abstract:0304

Apraisal of production of solar photovoltaic cells from cameroonian minerals

Lae Titia Marelle Yossa Ndjientcheu, César KapseuProcess Engineering, National Advanced School of Agro-Industrial Sciences,University of

Ngoundere,Ngaoundere,Cameroon

Cameroon is an Africa in miniature (paradise of minerals). All the Africa is found in Cameroon. As far minerals are concerned, many minerals are found in Cameroon include sand and/or quartz. These minerals contain silica from which silicon is obtained to produce solar photovoltaic cells. This study identifies the areas in Cameroon where sand/quartz are found. This study shows also that it is possible to produce solar cells from Cameroonian minerals. The bottlenecks are the following: equipments, knowhow and training. Cameroon can trust in its minerals to be the future emergent country.

Keywords: silica, silicon, solar cell, sand, quartz, photovoltaic


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Abstract:0305

Apraisal of production of solar photovoltaic cells from cameroonian minerals

Cesar Kapseu, Lae Titia Marelle Yossa NdjientcheuDepartment of Process Engineering of National Advanced School of Agro- Industrial Sciences of University

of Ngaoundere, Cameroon

Cameroon is an Africa in miniature (paradise of minerals). All the Africa is found in Cameroon. As far minerals are concerned, many minerals are found in Cameroon include sand and/or quartz. These minerals contain silica from which silicon is obtained to produce solar photovoltaic cells. This study identifies the areas in Cameroon where sand/quartz are found. This study shows also that it is possible to produce solar cells from Cameroonian minerals. The bottlenecks are the following: equipments, knowhow and training. Cameroon can trust in its minerals to be the future emergent country

Keywords: silica, silicon, solar cell, sand, quartz, photovoltaic

Abstract:0306

Photonics for innovative light management in photovoltaic modules

Bernhard Lamprecht, Gerhard PeharzInstitute for Surface Technologies and Photonics - Joanneum Research

We present photonic structures that optimize the light management within state-of-the-art photovoltaic modules. About 80% of the photovoltaic modules produced today use solar cells made of Silicon wafers. While international research on solar cells aiming at an increase of efficiency is well established the efforts to realize the roughly equal potential on module level are comparatively low. A substantial part of the light impinging the surface of a photovoltaic module is not absorbed by the solar cells:

• Most of the industrially produced solar cells have a full area rear-side metallization and a front-side metallization with a grid design. At this front-side grid typically 7-9% of the light impinging the solar cell is reflected or absorbed by the metal. This part of the light is lost and does not contribute to the generation of electricity.

• Additional optical losses within photovoltaic modules are related to the fact that not the full module area is covered with solar cells. Due to fabrication issues 10-15% of the module area are inactive gaps between cells or between a cell and the frame, respectively.

• Consequently about 20% of the light impinging the module area is lost due to the loss mechanism described above.

In this work we present optical structures which aim to decrease the optical losses by at least 50%. This would correspond to a power increase of about 10% for state-of-the-art modules. As a characteristic example for the realization we show planar light redirecting structures fabricated by UV nanoimprint lithography.

Keywords: photovoltaic modules, photonics, light management, nanoimprint lithography


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Abstract:0307

Synthesis and optical investigation of new conjugated polymer for organic optoelectronic devices

Chemek Mourad1, Khlayfia Dalila1, Florian Massuyeau2, Jany Wéry2, Eric Faulques2, Alimi Kamel1

1University of Monastir, Tunisia2University of Nantes, France

A new conjugated polymers based on Poly(N-vinylcarbazole) (PVK) and Poly(3-hexylthiophene) (P3HeT) was chemically synthesized using FeCl3 as an oxidant. vibrationnal, thermal and structural properties were studied by infrared spectroscopies, ATG analysis, TEM and SEM micrographic. Optical properties were investigated firstly by optical absorption and steady state fluorescence technique, then using the means of transient fluorescence spectroscopies. The use of PVK under the chemical synthesis was permitted to obtain new organic material, with better optical properties. The obtained material was mixed with single-walled carbon nanotubes in chloroform solution for various weight percent. Optical investigation on the prepared composites shows a charge transfers were occurred between the backbone of the copolymer and the carbon nanotubes.

Keywords: Poly(3-hexylthiophene),Poly(N-vinylcarbazole), single-walled carbon nanotubes, vibrational spectroscopy, optical absorption, steady-state and time resolved photoluminescence,

Abstract:0310

Synthesis and Characterization of CdSe, PbSe and CdTe Quantum Dots for Solar Energy Conversion

Marwa Fathy Bahnasi, Abd El Hady B. Kashyout, Ali A. ZidanElectronic Materials Research Department, Advanced Technology and New Materials Research Institute,

City of Scientific Research and Technological Applications

A simple route for the fabrication of CdSe, PbSe and CdTe quantum dot semiconductors are presented. The synthesis is based on the pyrolysis of organometallic reagents by injection into a hot coordinating solvent. This provides temporally discrete nucleation and permits controlled growth of macroscopic quantities of the nanocrystallites. XRD, HR-TEM, UV-Visible and PL were used to characterize the synthesized quantum dots. The results showed CdSe quantum dots with sizes ranging from 3 nm to 6 nm and PbSe quantum dots are about 6 nm and CdTe quantum dots are about 5 nm. The XRD exhibits clear peaks that confirm the wurtzite structure for CdSe and the cubic (zinc blende) for CdTe and PbSe. UVand PL results show that there are different band gaps for these materials which enabled the control of the optical properties and hence using them in different optoelectronic and solar cells devices. Quantum dots are used for sensitization of prepared TiO2 solar cell and showed improved efficiencies.

Keywords: Synthesis and Characterization of CdSe, PbSe and CdTe Quantum Dots for Solar Energy Conversion


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Abstract:0311

Theoretical model to relate morphology to device efficiency

Emine Neşe1,2, N. Clarke1

1Department of Chemistry, University of Durham, Durham, DH1 3LE, UK2Department of Physics, University of Dicle, Diyarbakır, Turkey

A computationally efficient method for modelling device performance, based on a mesoscopic drif-diffusion model in 3d microstructures, is developped. The photoactive layer modelling is based on numerically generated morphologies. This combined morphology/device performance modelling enabled us to explore how the efficiency depends on exciton/electron/hole mobilities, microstructure and length-scale as well as the surface effect.

PACS numbers: 72.20.Ee, 72.20.Jv, 72.80.Le, 82.35Cd, 881

Keywords: Theoretical model to relate morphology to device efficiency

Abstract:0312

Off-Grid Photo-Voltaic System Deployment as Alternate Energy Source in Rural Community in Pakistan

Mudassir Yasin BalochSchool of Information Technology & Engineering(SITE),University Of Ottawa,Canada

Pakistan’s electricity supply and demand difference has increased to rocketing 4,300 MW in June 2013 and power outage duration has been increased to 22 hours a day in sizzling summer which has gripped the whole nation socially and economically, so in current scenario, distributed energy sources like P-V based electricity generation system can help to energize remote load that is either far to reach national grid or national grid is unable to meet 24/7 electricity demand of a facility in Pakistan because alone Photo-voltaic and wind energy has generation capacity of 300,000 MW with very low carbon foot print, we have designed the system keeping in mind the whole electricity needs of a household, we will present the pictures of implemented system at the end of paper along with its analysis, it was implemented last summer in a small town of Pakistan on roof top of a building with the help of financial support from local community of town, for financial analysis we have assumed that project’s start up investment has been taken from bank as financial loan when such financial support is not available from local community and in order to see the system cost payback period, due to financial concerns, we had later on decided to step down our system for practical implementation from 3.1 kW to 1.0 kW and as a result total investment needed was reduced from US$ 21,000 in our calculations to US$ 8,000.

Keywords: implemented system, off-grid,P-V,Pakistan,electricity short fall,financial constraints,solar radiance,CAPEX


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Abstract:0314

Paper in organic electronics

Lucia Nicoleta Leonat, Eric Daniel G&322;owacki, Matthew White, Markus Scharber, Gundula Voss, Niyazi Serdar Sariciftci

Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University, Linz, Austria

Paper is omnipresent in our everyday life. We use it for printing, packaging, constructions, cleaning, etc. For sure paper is an important part of our future, as in the past years scientists introduced paper and cellulose based products, as substrate materials for low cost organic electronic devices. Among the most attractive properties of paper are its biodegradability, biocompatibility, flexibility, versatility and low cost. Here, recent work about electronic devices on paper is presented.

Keywords: paper, organic electronics

Abstract:0315

A Review on Recent Advances in Solar Cooking Applications

Rajith C.v, Eswaramoothy MuthusamyDepartment of Mechanical Engineering,Vimal Jyothi Engineering College, Chemperi, Kannur-670632,

Kerala, India

The increasing cost of modern cooking fuels and it’s uncertain in availability, peoples in the developing countries looking for an alternative energy cooking. Solar energy based cooking is the best compared to biomass based cooking due to indoor air pollution which causes health problems. An energy efficient and cost effective solar cooking is attracting the users and research on these issues is under progress from all over the world. In this paper, a detailed literature review is carried out on applications of solar cooking based on geometry, working principles, thermal modeling and economic analysis. Environmental impacts and future research and development potential of solar cookers are also considered in the study.

Keywords: V trough Solar Cooker, PCM Storage, Enhanced Heat Transfer


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Abstract:0316

Improved of cathode performance of nano-sized LiFePO4/CF composite using PTFE as carbon-floride source for lithium ion

batteries

Ercan Avci, Muhsin Mazman, Davut UzunTUBITAK, Marmara Research Center, Energy Institute, Battery Research Laboratory, Gebze, Kocaeli, Turkey

LiFePO4 (LFP) is considered to be one of the most promising cathode material for the next generation high-power lithium ion batteries due to its low cost, high safety, non-toxicity and a competitive theoretical capacity. They are envisioned to be used in electric vehicles and stationary energy storage systems for storing solar and wind power.

We report here a facile and efficient solid state synthesis of carbon and fluor coated lithium iron phosphate (LiFePO4/CF) cathode material is achieved via polymer-pyrolysis method using polytetrafluoroethylene (PTFE). The current investigation is comparatively analyzed with the results of the composites of LiFePO4/C (LFP/C) synthesized using polyetyhylene (PE), polystyrene-block-polybutadiene (PS) and sucrose as carbon precursors.

LFP/CF composite prepared using PTFE exhibits remarkable improvement in capacity, cyclability and rate capability compared to those of LFP/C prepared using PE, PS and sucrose as carbon precursors. The specific discharge capacities as high as 162 mAh g-1 (theoretical capacity: 170 mAh g-1) at 0.2 C (5 h.) and 112 mAh g-1 at 10 C (6 min.) rates were achieved with LFP/CF (Fig. 1). In addition, the composite exhibits a long-term cycling stability with the capacity loss of only 8% after 1000 cycles. PTFE shifts the size distribution of the composite to nanometer scale (approximately 120 nm), however the addition of sucrose and the other polymers do not have such an effect. According to TEM and XPS analysis, LFP particles are mostly coated with a few nanometers thick C-F layer forming a core-shell structure.

Keywords: Lithium ion battery, LiFePO4 cathode, carbon coating

Rate capability of different LFP composites.


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Abstract:0321

Synchrotron based analysis of the Cu(In,Ga)Se2/CdS and Cu(In,Ga)Se2/ZnS interfaces using soft x-ray photoemission spectroscopy (SXPS) and near edge x-ray absorption fine

structure spectroscopy (NEXAFS)

Bünyamin Ümsür, Wolfram Calvet, Iver Lauermann, Martha Ch. Lux SteinerInstitute for Heterogeneous Materials Systems, Helmholtz-Zentrum-Berlin, Berlin, Germany

Thin film solar cells based on the chalcopyrite absorber material Cu(In,Ga)Se2 have the highest potential to reduce fabrication costs in photovoltaics since material consumption and requirements in production are low. Until now, efficiencies above 20% (lab-scale) and above 15% (fabrication-scale) have been obtained for single junction devices, starting to compete with silicon-based devices. It is assumed that besides defects in the bulk material, the interface between the absorber and buffer layer mainly based on CdS plays an important role with respect to band alignment and appearance of interface states causing recombination in this region. One research aim is to replace CdS by a less toxic alternative such as ZnS. A second point that has to be considered is inter-diffusion. Especially, the diffusion of Cd into the chalcopyrite absorber with its impact on PV cell performance is not clarified yet. In order to study this more in detail, synchrotron radiation based techniques such as SXPS and NEXAFS with a tunable light source are well suited. In this work we have investigated Cu(In,Ga)Se2 absorbers covered by thin layers of CdS and ZnS by means of chemical bath deposition (CBD). In a second step, the samples have been annealed under ambient conditions up to 200 °C to study possible changes induced by inter-diffusion. To get a closer insight into the relevant interface region, the ZnS or CdS films have been removed by a short etching step in diluted HCl prior to the investigation with synchrotron light.

Keywords: Photovoltaics, Thin films, Chalcopyrite, SXPS, NEXAFS, Interface

Abstract:0323

New Push-Pull Type Material Having Spirobifluorene as π-spacer for DSSCs

Kadir Demirak1, Mustafa Can2, Hakan Bilgili1, Cihan Ozsoy1, Ceylan Zafer1, Serafettin Demic3, Ebubekir Sıddık Icli1

1Ege University, Solar Energy Institute, 35100-Izmir, Turkey2Izmir Katip Celebi University, Faculty of Engineering and Architecture, Department of Engineering

Sciences, 35620-Izmir, Turkey3Izmir Katip Celebi University, Faculty of Engineering and Architecture, Department of Materials Science

and Engineering, 35620-Izmir, Turkey

Two novel organic photo-sensitizers based on spirobifluoerene were designed, synthesized and characterized for efficient dye-sensitized solar cells. Their absorption spectra, electrochemical and photovoltaic properties have been investigated. Soluble alkoxy derivative of triarylamine used as donor, spirobifluorene as π-spacer and cyanoacrylic acid as acceptor and anchoring group as well. The

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unsymmetrical sensitizers synthesized, anchored onto TiO2 and were tested in a volatile electrolyte. MK-160 and MK-162-sensitized solar cells give a short-curcuit current of 4.46 mA/cm2 and 4.92 mA/cm2, an open-curcuit voltage of 530 mV and 520 mV and a fill factor of 0.62 and 0.59, resulting an overall conversion efficiencies of 1.45 % and 1.52 % where Z907 has 14.51 mA/cm2, 620 mV, 0.45 and 4.08 % photovoltaic parameters under standart AM 1.5 illumination.

Keywords: DSSC, spirobifluorene, push-pull

J-V curves of MK-160 and MK-162 sensizitized solar cells

Abstract:0324

Influence of annealing duration on polysilicon formed by solid phase crystallization (SPC) process on glass substrate

Mehmet Karaman1, Özge Tüzün Özmen2, Raşit Turan3

1Center for Solar Energy Research an Applications (GÜNAM), Middle East Technical University; Ankara, Turkey

2Department of Physics, Düzce University, Düzce, Turkey3Department of Physics, Middle East Technical University,Ankara, Turkey

A-Si thin films need to crystallization for the conversion to poly-Si thin film. Solid Phase Crystallization (SPC) technique is one of the favourable way to crystallize the a-Si which is evaporated by e-beam evaporated amorphous silicon (a-Si) on low cost foreign substrate such as glass. The deposition of a-Si is followed by the thermal annealing at 600°C for different durations from 8h to 36h. This long range of crystallization annealing duration give the chance to analyze the transition from amorphous phase to crystalline phase. The crystallinity and stress analysis were performed by Raman Spectroscopy. The sample annealed for 8h gave a Raman peak with a large amorphous phase around 480cm-1 which indicates the amorphous phase in the film. Annealing for 8h was followed by the annealing for 10.5h and 12h. However, the intensity of Raman results are quite low due to the a-Si+poly-Si mixtured structure. Starting from 15h annealing at 600oC, Raman analysis shows the fully crystallization for all annealing durations. The stress analysis was studied by the Raman peak positions. The results shows that all samples have the tensile stress due to the mismatch of thermal expension coefficient of Si film and glass substrate. The preferred orientation and crystallite sizes of thin films were depicted by using X-ray diffraction (XRD) technique. The orientation of <111> was the preferred orientation for all SPC samples. Additionally, the crystallite size value of 160Å was achieved by using SPC at 600oC for 15h.

Keywords: Electron Beam, Amorphous Silicon, Crystallization

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Abstract:0326

Voltage effect on magneconductance in an ambipolar polymer device

Moufid Radaoui1, Amel Benfredj1, Marek Havlicek2, Samir Romdhane1, Daniel Egbe2, Habib Bouchriha1

1Laboratoire Matériaux Avancés et Phénomènes Quantiques, Faculté des Sciences de Tunis, Université El Manar, 2092 Campus Universitaire, Tunis, Tunisia

2Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University Linz, Altenbergerstr. 69, 4040 Linz, Austria

Thin film of An anthracene containing poly(p-phenylene-ethynylene)-alt-poly(p-phenylene-vinylene) (PPE-PPV) denoted AnE-PV stat was prepared using spin coating technique. The diode structure is an ITO/PEDOT:PSS/AnE-PVstat/LiF/Al. We report the observed magneto-conductance (MC) under a weak magnetic field (<1T). Positive MC is observed and reaches up to 2.4% at a magnetic field of 0.7T. It is found that with the increase of the voltage, the MC effect decrease. The experimental data is analyzed in the context of the e-h pair model, based on the Stochastic Liouville Equation. The experimental data has been well reproduced by the model described above. From these fittings, we provide an estimate for several parameters such as the hyperfine field, recombination and dissociation rates of the singlet and triplet states.

Keywords: magnetoconductance, e-h pair model, AnE-PVstat

Abstract:0328

Biodegradation of Agricultural Waste and Pigdung in Anaerobic Digester

Nkiruka Francisca OparakuNational Center for Energy Research and Development,university of Nigeria,Nsukka

Anaerobic fermentation of municipal, agricultural and domestic wastes in a digester to produce biogas; methane gas and mixtures of other gases, could help in reduction of environmental degradation occasioned by indiscriminate felling of trees and dumping of refuse. Biogas is a colourless and flammable gas used for cooking, lighting and electricity generation. In this experiment, agricultural waste; Carpet grass (Avonopus affinis), cassava peels (Manihot esculenta) and pig dung were used for biogas production. The wastes were prepared as A-AV1 (50% of pig dung and 50% of carpet grass), C-AV2 (only pig dung), D-AV3 (30%carpet grass and 70% of pig dung), F-AV4 (10% carpet grass and 90% of pig dung) B- MA1(50% of pig dung and 50% of cassava), E -MA2(30% cassava and 70% of pig dung), G- MA3 (10% cassava and 90% of pig dung). They were subsequently charged into nine 32L capacity digesters in ratio of approximately 1:1 of water to waste, and waste to waste was.1:1, 3:7, 1:9 and the control that had only pig dung were subjected to anaerobic digestion under a 30 day retention period and temperature range of 35 to 37°C, which of course, is within the range for the optimum production of biogas. Results obtained showed that the D-AV3 (30%carpet grass and 70% of pig dung)


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had higher cumulative biogas yields, while C- AV3 (only pig dung) had the lowest volume of gas. Results indicate that the carpet grass has the capability of producing biogas more than pig dung under the same condition.

Keywords: Biogas production, carpet grass,cassava, pig dung. co-digestion, flammable gas, mesophilic temperature

Abstract:0330

Structural and Optical properties of Aluminum Doped ZnO Thin Film Synthesized by SILAR Technique

Adeleke Joshua Toyin, Alabi Aderemi Babatunde, Daramola Oladotun Olanrewaju, Ayeni Adewale Bidemi

Department of Physics, University of Ilorin, Ilorin, Nigeria

Aluminum doped zinc oxide (AZO) thin film was synthesized and deposited on microscopic glass substrate via successive ion layer adsorption and reaction (SILAR) route. Fourier Transform Infra-Red (FTIR) spectroscopy analysis was carried out to identify the elemental constituents of the AZO film. Variation of the optical and structural properties of the film with annealing temperature was studied using UV – VIS and XRD techniques respectively. From the results obtained, FTIR gives O-H stretching of hydroxyl group at 3132.50cm-1 Zn-O stretching of ZnO at 363.59cm-1 and an Al-O stretching at 954.80cm-1. The absorbance of the AZO film was found to be low in the VI/NIR regions (200nm) and high in the UV region (400nm). Its absorbance increases while its band gap decreases with increase in the annealing temperature. Structural analysis from the XRD reveals that c – axis orientation was significantly enhanced due to Al incorporation. The crystallite size obtained for different annealing temperatures are 17.57 nm for AZO at 350 oC, 19.58 nm for AZO at 450 oC, and 24.97 nm for AZO at 550 oC. Doping as well as the annealing temperature was observed to significantly modify the film structural and optical properties.

Keywords: Al-ZnO, SILAR, FTIR, thin films, XRD, annealing

Abstract:0332

Designing & Manufacturing of a Standalone Two Axis Active Solar Tracker Using a Microcontroller

Samed Çetinkaya, Süleyman Kahraman, Hacı Ali Çetinkara, Hüsnü Salih GüderDepartment of Physics, Mustafa Kemal University, Hatay, Turkey

As an alternative to carbon-based fuels, the development of green energy resources has become one of the most important tasks for researchers in recent decades. Among the diverse, renewable energy sources, solar energy is probably the best for meeting the energy demands of modern society. In recent

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years, due to a rapid increase in the demand for renewable energy sources, the production of solar cells has increased significantly.

Many researchers have conducted to develop some methods to increase the efficiency of photovoltaic systems. One efficient method is to track the sun during the day through a solar tracker system. Many of the solar panels currently used on the world are fixed and they cannot collect the sunlight in a right angle all day. It is obvious that the efficiency of solar conversion can be increased in case of using a tracker. Up to now, remarkable studies have been published on sun tracking and there are lots of patents. But those systems are typically expensive and quite complicated.

In this study we have designed and manufactured a simple and low cost two axis solar tracking system consist of a 16F84A microcontroller, two stepper motors, a Darlington transistor.

Keywords: Solar tracking system, Microcontroller, Stepper motor, Light Dependent Resistor (LDR).

Abstract:0333

Structural, Optical and Electrical properties of nanocrystalline Cu2O thin films grown by Pulsed Laser Deposition

Syed Farid Uddin Farhad1,2, David Cherns1

1School of Physics, University of Bristol, HH Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL, United Kingdom.

2Industrial Physics Division, BCSIR Laboratories, Dhaka 1250; Bangladesh Council of Scientific and Industrial Research, Bangladesh.

Phase pure Cu2O is desirable as an absorber material for solar cells using ZnO electrodes because of its reported bandgap (~2.1 eV), a suitable band alignment with ZnO, and the ability to dope both n- and p-type. Pulsed laser deposition (PLD) has been used to grow Cu2O on ZnO and other substrates at low substrate temperatures and in oxygen ambient. Transmission electron microscopy and X-ray diffraction analyses showed a single phase Cu2O with (111) and (200) textures while growing at 200 C and 25 C substrate temperatures respectively. Electrical measurements, including conductivity and electrochemical Mott-Schottky measurements, showed n-type behaviour with resistivity as low as ~6×10-3 Ω.cm, much lower than previously reported results at ~25 C without any oxygen injection in the PLD chamber. The as grown Cu2O thin films also showed a transition from highly conductive n-type to semi-insulating (~9×106 Ω.cm) and finally p-type behaviour as the oxygen concentration was increased. UV-Vis diffuse reflectance spectroscopy was used to estimate the optical bandgap of the polycrystalline thin films to be in the range 2.01 -2.10 eV.

The paper will describe the growth, structural and electrical properties of the Cu2O films, and the properties of Cu2O solar cells grown on ZnO electrodes.

Keywords: Phase pure Cu2O, n-type, PLD, low resistive Cu2O


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Abstract:0338

Custom-made, Cultural Identity blended Training in PV Sizing, Installation and Maintenance in Kenya

Justus Simiyu, Charles Obure, Sebastian Waita, Bernard AdudaDepartment lof Physics, University of Nairobi, Nairobi, Kenya

Solar electrification has emerged as a leading alternative to grid-based rural electrification in many developing countries, Kenya being one of them. This has become the appropriate technology for rural electrification as it is a market-driven subsector as opposed to the government controlled rural electrification programme which has been slow to penetrate. Slow penetration of the national grid to rural Kenya has been occasioned by several factors among them being the large geographical imbalance in electricity demand and supply. The pv market has been mainly stand alone solar home systems but the trend has changed with introduction of emerging concepts such as pv mini grids, solar lanterns, grid tied pv systems. Solar lanterns as much as they provide clean and higher quality light, they closely resemble the very traditional kerosene tin lamps. They have therefore been readily acceptable as they still appear ‘cultural’ in shape and also portability besides being more affordable compared to solar home system.

There is need for capacity building to handle these emerging technologies effectively. The Department of Physics developed a custom made pv training to suit the diversity of the Kenyan culture that covers the known solar home systems and the new solar lanterns concept. This has attracted NGOs, international funding agencies and the government to engage training centers to facilitate the capacity building. A curriculum for the same training has been developed at basic, intermediate and advanced training with the university mandated to train the advanced level that includes grid connected and hybrid systems.

Keywords: rural electrification, culture, solar lanterns, pv education

Abstract:0339

Structural and optical properties of glassy Ge20Se80-xSx as photovoltaic material

Mostafa Saad Ali, Mahmoud Mohamed Dongol, Mohammed Mohammed NassaryNano & Thin Film Lab, Physics Department, Faculty of Science, South Valley University, 6-Kilo Road, Qena

83523, Egypt

The structural properties of bulk Ge20Se80-xSx with(x=25, 15) glasses prepared by melt-quench technique have been studied using x-ray diffraction. Analysis of the total distribution function T(r) has been used to investigate the short range order of Ge20Se80-xSx glasses.

Optical properties of the as-deposited films of Ge20Se80-xSx prepared by thermal evaporation technique, were investigated using spectrophotometric measurements of both transmittance(T) and reflectance(R) at normal incidence of light in the wavelength range, 200-1100 nm. The obtained data


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of refractive index, and absorption index, were used to estimate the type of transition and the optical band gap Eg

Keywords: Chalcogenide, Glasses, Thin films, X-ray diffraction, Optical properties,photovoltaic material

Abstract:0340

Experimental Study of Flat-Plate Solar Collector System Dynamics Control Oriented to Increase Energy Capturing

Efficiency

Momen Mohammad SughayyerMechanical Engineering Department, Palestine Polytechnic University, Hebron, Palestine

Internationally, many countries are investing in solar energy projects, mainly for producing electricity and heating. In Palestine, using solar energy for water heating in domestic and commercial applications accounts for a very significant part of daily energy use. Basically, most of the adopted systems comprise flat-plate solar collectors, storage tanks, and water as working fluid. The systems designs are based on fixed solar plate and storage capacitance, which reduces the heat capturing efficiency, especially in winter season.

In this contribution, a control strategy that is based on a variable capacitance heat storage system is proposed. Given, different applications require appropriate sizing of the main components; the flow rate to obtain the sought efficiency and the storage capacity are assumed to be variable. For this purpose, an experimental system has been adopted to simulate the real system and to identify the system parameters and the dynamical behavior, which is based on the size of the collectors and the average heat load. The adopted solar water heating system is designed to meet local typical domestic needs for the whole day. Experimental data for solar radiation, wind speed, and ambient temperature are obtained. Also, the measurements included the flow and the inside tank temperatures at different levels for different conditions. The obtained parameters are used in the system dynamics control that allow for higher solar energy capturing and heat-transfer efficiencies.

Keywords: Solar energy, flat-plate, capturing efficiency, control, variable storage


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Abstract:0341

Molecular Engineering of Carbazole Based Metal Free Organic Dyes for Electrochemical Solar Cells

Deniz Aykut1, Ayşenur Karaönder2, Emre Sefer2, Sermet Koyuncu2, Ceylan Zafer1

1Solar Energy Instutute, Ege University, TR-35100 Izmir, Turkey2Canakkale Onsekiz Mart University, Can Vocat Sch, TR-17400 Canakkale, Turkey

Dye-sensitized solar cells (DSSCs) have attracted attention of the researhers due to high efficiency with low cost easy fabrication and good stability [1]. Since discovery from Graetzel et al [2], the search for new materials with good performance as well as the improvement in device fabrication has been a subject of importance. Novel organic dyes, which have a bicarbazole derivative as an electron donor and a cyanoacrylic acid moiety as an electron acceptor and an anchoring group, connected with quinoxaline bridging thiophene as a pi-conjugated system, were designed and synthesized. Three kinds of alkyl chain contained 4,6 and 12 carbon were used in order to hinder back electron transfer. Electrochemical and optical properties of carbazole based dye were studied by impedance spectroscopy, cyclic voltametry, UV-Vis absorbtion and fluorescence spectroscopy, respectively. Besides, we studied PV performance of dye-sensitized solar cells using an ionic liquid as the electrolyte.

We gratefully acknowledge the support from Scientific and Technical Research Council of Turkey (TUBITAK); project number: 110T830

Keywords: Metal Free Organic Dyes, Carbazole, Electrochemical Solar Cell

IPCE Graph

IPCE Spectra of TPDC dyes.

J-V Graph

Current Density-Voltage Graphics of TPDC dye under standart conditions


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Structure

Molecular Structure of TPDCX

Abstract:0343

Improving the efficiency of organic photovoltaic cells based on the CuPc/C60 couple by using ZnO thin film as buffer layer

Mazabalo Baneto1, Yendoube Lare1, Koffi Jondo1, Kossi Napo1, Jean Christian Bernède2

1CUER-UL, Department of Physics, University of Lomé, Lomé - Togo2LAMP, Faculty of Sciences and Techniques, University of Nantes, Nantes-France

Zinc oxide is a material that belongs to the family of transparent conductive oxides (TCO). Its nontoxicity, abundant availability in the earth, easy fabrication, good electrical and optical behavior compared with other materials such as tin oxide (SnO2) and indium tin oxide (ITO) make this material favorable for multiple applications. Its conductivity can reach 104 (Ω.cm)-1 by doping. Thus it can be used as a buffer layer in the multi-heterojunction organic solar cells to resolve the problem of charge transport at the interface [electrode / organic material] where exists a potential barrier.

The effect of zinc oxide (ZnO) buffer layer on the performances of inverted multilayers organic solar cells has been studied. Aluminium doped ZnO (ZnO:Al) conductive films and insulating ZnO films obtained by chemical bath deposition have been probed. The ZnO buffer layer has been introduced between the ITO cathode and the Organic acceptor. The cells are based on the multilayer junctions with structure ITO / ZnO or ZnO: Al / BCP/C60/CuPc/MoO3/Au/Al

The organic photovoltaic cells performances improvement depends of the ZnO layer introduced. ZnO:Al conductive layers decreases the potential barrier at the interface cathode/organic. This allows decreasing the series resistance which improves significantly the cell efficiency.

Insulating ZnO increases only slightly the solar cells performance by increasing significantly the shunt resistance and therefore the open circuit voltage of the cells.

Keywords: Zinc oxide, chemical bath deposition, organic solar cells.


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Abstract:0344

Improvement of Electrical Performance of Inorganic-Organic Hybrid Solar Cells by Dopping of CuInS2 and CuInS2:ZnS Core

–Shell Quantum Particles in Polymer

Cihan Özsoy, Deniz Aykut, Burak Gültekin, Ceylan ZaferSolar Energy Institute, Ege University, Izmir, Turkey

The quantum dot based organic hybrid solar cell has attracted a great attention due quantum dot’s unique properties such as quantum confinement effect, multiple exciton production and easily modification of band gap. We present here the effect of optimal dopping ratio of CuInS2 core quantum dots with different shell, oleylamine and ZnS. It was aimed that as the light reached to quantum dot, electron promoted to upper energy level and electron transport and confined to the shell and hole was confined to the core[1,2]. Thus gradually doped poly(3-hexylthiophene 2,5 diyl): ([6,6]-phenyl-C71 butyric acid methyl ester) (P3HT:PCBM) bulk heterojunction have been taken into account in order to improve the efficiency. For this purpose crystal structure of CuInS2 core was determined by XRD, and diameter distribution of oleylamine and ZnS coated quantum dots was obtained by SAXS analysis. Photovoltaic performance was investigated under 1.5 AM (100mW/cm2) and incident photo current efficiency (IPCE) was performed in order to obtain the external quantum efficiency. Atomic force microscope (AFM) was used in order to monitor the changes in the surface morphology.

Keywords: Quantum Dot, Organic Solar Cell, Hybrid Solar Cell

I-V curve of Quantum Dot-Dopped Organic Solar Cell


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Abstract:0345

Synthesis and Measurement of the Optoelectronic Properties of Cadmium Sulfide Thin Films via Non-standard Spectroscopic

Techniques

Prosper Ahmed AmuquandohDepartment of Industrial Engineering and Information Technology, University of Trieste, Italy

The deposition of materials in the thin film form has been the subject of intense research over the past decades due to their applications in optoelectronic devices. Cadmium sulfide is one of the most investigated thin film semiconductors because of its proven application as a window material in thin film solar cells. The synthesis and measurement of the optoelectronic properties of Cadmium Sulfide (CdS) thin films using non-standard spectroscopic techniques are reported. The CdS thin films were synthesized via the chemical bath deposition method. An alkaline solution of Cadmium Sulfate (5.4 mg), thiourea (282 mg), ammonium hydroxide (7 ml) and water (43 ml) was prepared and heated in a 75 ºC water bath. The resulting CdS thin films were adsorb onto clean glass substrates. The spectral responsivity of the CdS thin films was measured using a monochromator–grating based spectral responsivity measurement system, in the voltage biasing mode. The electrical property (i.e sheet resistance) was measured via the von der Pauw method. Three samples were considered: a standard CdS film, an annealed film, and an annealed and doped film. The spectral responsivities of all the three samples peaked between 440.00 nm and 480.00 nm. The highest spectral responsivity [i.e 2.35×10^(-5) A/W] and lowest sheet resistance [i.e 1.07×10^10 Ω/sq] were observed for the later sample, with the former one showing the lowest responsivity [1.85×10^(-5) A/W] and highest sheet resistance (i.e 1.04×10^12 Ω/sq]. For all the samples, it was observed that the spectral responsivity increased with bias voltage.

Keywords: CdS, Thin films, Chemical bath deposition, spectral responsivity, Sheet resistance

Abstract:0347

Material structure – photovoltaic performance relationship for organic bulk heterojunction solar cells based PPV-PPE

conjugated polymer

Olga A. Mukhacheva1, Pavel A. Troshin1, Andrey E. Goryachev1, Daniel A. M. Egbe2, Niyazi Serdar Sariciftci2

1Institute for Problems of Chemical Physics of Russian Academy of Sciences, Semenov Prospect 1, Chernogolovka, Moscow region, 142432, Russia

2Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz, Austria

Several conjugated PPV-PPE copolymers were studied as electron donor materials in bulk heterojunction organic solar cells in combination with a library of electron acceptor fullerene derivatives. It was shown that molecular structure and solubility of the fullerene counterpart affect significantly photovoltaic performance of both polymers. Use of [60]PCBM as electron acceptor material yielded quite moderate


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power conversion efficiencies. The best results were achieved when some fullerene derivatives with better suiting molecular structures and solubility were applied. In some cases the photovoltaic performance of the polymer/fullerene blends shows direct correlation with the molecular structures of the materials.

The obtained results suggest that every newly designed conjugated polymer should be evaluated in solar cells using a library of fullerene derivatives instead of just conventional PCBMs. We believe that only this combinatorial approach might bring the best performing donor/acceptor combinations for future generations of efficient organic solar cells.

Keywords: solar cells, fullerene derivatives

Abstract:0351

Cost effective route for the preparation of CZTS thin films for low cost solar cells

Ahmed Ihlal1, Hassan Kirou1, Lahbib Alahyane1, Abdeslam Elfanaoui1, Elhoucine Elhamri1, Elhassane Ihalane1, Khalid Bouabid1, Xavier Portier2

1Laboratoire Matériaux et Energies Renouvelables (LMER), University Ibn Zohr, Dep. Physique, Faculté des Sciences B.P.8106, Hay Dakhla, 80000, Agadir, Morocco

2CIMAP, ENSICAEN/ UMR CNRS 6176, 6-Boulevard du Maréchal Juin 14050 Caen Cedex

Due to their promising potential to reach cost effective PV-generated electricity, thin film based solar cells are continuing to gain more and more popularity. Recently, CIGS based solar cells on polymer flexible substrate have achieved new record efficiency of 20.4% close to their counterpart based on crystalline silicon. However, toxicity of certain elements and scarcity of other elements such as Indium is expected to limit the potential yield of CIGS based PV to less than 100 Gigawatts per year and thus cannot meet the Terawatt level of renewable electricity needed to ensure a sustainable development worldwide. Thus, searching alternative earth-abundant metallic elements is a challenge for the scientific community. Zinc and Tin are nowadays tested as an alternative for Indium. CZTS based solar cells, since the announcement of IBM a breaking record efficiency of 11.1%, are being near the level needed for commercial solar panels. In this study, we present our recent results concerning the preparation CZTS thin films using simple and cost effective growth techniques: SILAR and electrodeposition. Influence of deposition parameters on the optical and structural properties of our films are presented and discussed.

Keywords: CZTS, Thin films, solar cells, cost effective, electrodeposition, SILAR


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Abstract:0352

Electrophoretic deposition of TiO2/Nb2O5 composite electrode thin films for photovoltaic application

John Njagi Nguu1, Robinson Musembi2, Francis Nyongesa2, Bernard Aduda2

1Department of Science & Engineering, Daystar University, Kenya2Department of Physics, University of Nairobi, Kenya

Nano-sized powders of titanium dioxide (TiO2) and niobium (v) oxide (Nb2O5) were used to fabricate TiO2/Nb2O5 composites thin films by electrophoretic deposition (EPD) technique. In EPD technique, charged particles suspended in a liquid are forced to move towards and deposit on an oppositely charged electrode upon application of electric field. The TiO2 and Nb2O5 powders, together with magnesium nitrate hexahydrate pellets, were suspended in propan-2-ol inside an EPD cell. The electrodes, placed 1.2cm apart, were immersed in the suspension and a DC potential applied across them. Key EPD process parameters, which include applied DC electric field, deposition time, and solid concentration in suspension, were optimized through visual inspection and from UV-Vis-NIR spectrophotometer spectra. The deposited thin films with highest (55%) transmittance were obtained using deposition time of 90s, powder concentration of 0.01g/40ml, and applied DC voltage of 35V. This combination (90s, 0.01g/40mL, & 35V) became the optimum EPD values for fabricating TiO2/Nb2O5 composite thin films. The XRD micrographs confirmed that TiO2 and Nb2O5 particles were present in the composite film. Visual inspection of and SEM images of the composite electrode thin films showed that porous films of high quality with well controlled morphology can be deposited using the EPD technique.

Keywords: Electrophoretic deposition (EPD), Transmittance, TiO2/Nb2O5 composite electrode thin films, Solar energy materials, Photovoltaic applications

Abstract:0353

Energy efficient house with integrated photovoltaics – a case study from South Africa

Sosten Ziuku1, Edson L. Meyer2

1Energy Technology Institute, SIRDC, Harare, Zimbabwe2Institute of Technology, University of Fort Hare, Alice 5700, South Africa

An energy efficient dwelling with building integrated photovoltaics has been built and monitored at the University of Fort Hare, Alice campus, South Africa. This was part of an initiative to implement energy efficiency measures and utilize renewable energies in the residential sector. The PV generator was mounted on the northern roof as part of the building envelope thereby replacing the conventional roofing material as well as supplying the electrical energy requirements of the building appliances. Flat plate solar water heaters supply hot water to the household. Passive solar design concepts were used to ensure passive indoor heating and cooling using direct solar access and natural ventilation, respectively. A data acquisition system that monitors electrical and thermal performance of photovoltaic panels was installed. Indoor and outdoor weather conditions were also recorded. This paper discusses thermal


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and electrical performance of the energy efficient solar house. Indoor temperatures were observed to remain within the thermal comfort range for more than 80% of the time. The energy efficient solar house has the potential to mitigate 12.40 tonnes of CO2 equivalent per annum. The integration of photovoltaic panels as an architectural feature of energy efficient houses was proven to be technically feasible and economically viable in South African conditions. The project showcases renewable energy utilization to policy makers and stakeholders in the building sector.

Keywords: Building integrated photovoltaics, passive solar design, mitigating ghg, payback period.

Abstract:0354

Solar Energy for Environmental Remediation

Dickson Mubera AndalaMultimedia University of Kenya

Environmental pollution is an intractable global environmental problem that emanates from increased anthropogenic activities such as agricultural, mining, manufacturing, pharmaceutical and petroleum industries. This work describes the use of nanotechnology in waste water treatment through the utilization of solar energy in photoremediation of organic pollutants. We exploit the use titanium dioxide nanofibers and nanoparticles to remove both organic and inorganic pollutants in water. The titanium dioxide nanoparticles are adsorbed onto a reactor through which contaminated water flows under sunlight irradiation to initiate photooxidation and reduction. The rate of photodegradation of the pollutants was monitored by by UV-visible spectroscopy. The main advantages of this technique lies in its ease of use, portability of the reactor and recyclability making it cheap to use in rural areas analogous to solar energy panels.

Keywords: Titania dioxide, photoremediation

Abstract:0358

Unsteady Double Diffusive Natural Convection in Porous Media-Application to CO2 Storage in Deep Saline Aquifer Tank

Souhail Bouzgarrou1, Hosni Souhail Harzallah2, Kalifa Slimi3

1National Engineering School of Tunis2National Engineering School of Monastir

3Institut supérieur du Transport et de la Logistique de Sousse

In this paper, we aim to investigate numerically the storage of CO2 at supercritical conditions in deep saline aquifer reservoirs. Numerical simulations were carried out on non-deformable saturated porous material inside a vertical enclosure, assumed to be impermeable and insulated on three sides. The porous medium is considered to be homogeneous and isotropic with constant thermo-physical properties with the exception of the density of the fluid varying according to Boussinesq approximations.


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A dynamic model assuming that flow is two-dimensional and obeying to Darcy’s law for motion has been used. We assume also that the thermal equilibrium assumption (LTE) is valid. The set of the conservation equations along with the appropriate initial and boundary conditions have been resolved numerically by the classical finite volume method (Patankar, 1980).

Spatio-temporal variations of different state variables such as pressure, velocity, temperature and concentration were numerically simulated and plotted versus different controlling parameters particularly, thermal and solutal Rayleigh numbers, RaT and Ras; Lewis number; Le and the reservoir’s aspect ratio, A. Great attention was paid to examine the sensitivity of fluid flow and heat and mass transfer rates according to the reservoir form and the operating conditions.

Keywords: unsteady, natural convection, thermosolutal, porous medium, numerical simulation, deep saline aquifer tank, CO2 Storage

Abstract:0360

Growth and characterization of ZnO nanowire for photovoltaic application obtained by MOCVD

Georgies Alene AsresDepartment of Physics, Arba Minch University, Arba Minch, Ethiiopia

Solar cell is a potential source of renewable energy. In terms of technology, price and materials used the solar cell has three basic generations. It is believed by many scientists that “third generation” solar cell devices offer a potential breakthrough in meeting current and future global electricity supply. There are different approaches to realize the third generation solar cell devices. The purpose of this project is to enforce the development of a new concept type II Zinc Oxide (ZnO) nanowire core Cadmium telluride (CdTe) shell based solar cell, one approach for the realization of the third generation solar cell device. The specific objective is to grow a ZnO nanowires on fluorine doped polycrystalline tin oxide (SnO2) substrate with the required dimension and orientation, which is a building block for this new concept solar cell.

The method we have used to synthesize the ZnO nanowire is metal-organic chemical vapor deposition (MOCVD). In the experiments we have changed three different growth conditions: deposition time, growth temperature and growth pressure and investigate their influence on the ZnO NWs especially on their morphology. ZnO NWs were successfully synthesized on a fluorine-doped polycrystalline SnO2 substrate by using Zinc Acetylacetonate(Zn(AcAc)2)and oxygen as a precursor. We have analyzed the effect of the three different growth conditions on the morphology and size of the grown ZnO NWs by using state of the art materials characterization techniques such as SEM and XRD.

Keywords: ZnO, nanowire, solar cell, chemical vapor deposition, characterization


256

Abstract:0361

Xray2RDF: a computer program to obtain the radial distribution function from X-ray diffraction data

Mostafa Saad Ali, Mahmoud Mohammed Dongol, Mohammed Mohammed NassaryNano & Thin Film Lab, Physics Department, Faculty of Science, South Valley University, 6-Kilo Road, Qena

83523, Egypt

Xray2RDF is a computer program to obtain the radial distribution function(RDF) from X-ray diffraction data of amorphous materials.Xray2RDF has been written in matlab. Xray2RDF can compute the following structural information: total radial distribution functions(T(r)) and structure factors for X-ray scattering, coordination numbers, bond-angle. User-friendly interface, convenient input and output of the measured and calculated data in the form of Excel and text files are also a feature of this software

Keywords: radial distribution function; amorphous structure determination; structure factor;matlab

Xray2RDF interface

the GUI of the program

Abstract:0362

The Synthesis of Oligothiophene Derivatives: Conductivity and Thermal Properties

Emel Karaboga1, Emin Istif1, Demet Karaca Balta1, Sureyya Aydin Yuksel2, Nergis Arsu1

1Yildiz Technical University, Chemistry Department2Yildiz Technical University, Physics Department

Oligothiophenes and their functional derivatives have been extensively studied because of their numerous applications in OLEDs, OFETs, chemosensors, biosensors, and electrochromic devices among others. The structurally defined and monodisperse oligomers are excellent model compounds for the corresponding polydisperse polymers, which include chain length distributions, defects and


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interruptions of the conjugated chains. The investigating of the various properties in dependence of the chain length allows establishing valuable structure-property relationships and extrapolations to the polymer.

Functional oligothiophenes are generally synthesized by either oxidative homocoupling or metal-catalyzed C-C-coupling, such as Kumada, Suzuki, Sonogashira, Stille, and Negishi type reactions.

In this study various oligothiphenes were synthesized by using Suzuki type reactions. Synthesized oligothiophene’s end was capped with thioxanthone naphthalene.

The effect of thiophene chain length and the end group on the hole/electron mobility and conductivities were determined by space charge limited current model using current density voltage characteristics. Thermal properties and organic photovoltaic applications of novel oligothiophenes were also investigated in detail.

References;

[1]. H. Shirakawa, E.J. Lewis, A.G. McDiarmid, C.K. Chiang and A.J. Heeper, J. Chem. Soc. Chem. Commun., 1977, 578.[2]. D.K. Balta, N. Cetiner, G. Temel, Z. Turgut, N. Arsu, “An annelated thioxanthone as a new Type II initiator”, J. Of Photochem. And Photobiol. A-Chemistry, 2008, 199 (2-3), 316-321.[3]. Amaresh Mishra, Chang-Qi Ma and Peter Bauerle, “Functional oligothiophenes: Molecular design for multidimensional nanoarchitetures and their applications” Chem. Rev. 2009, 109, 1141-1276.

Keywords: oligothiophenes, conductivity, thioxanthone

Abstract:0363

Sustainability 0f Bioenergy in Rural Tranformation

Nkiruka Francisca Oparaku, Ogbonna Ukachukwu OparakuNational centre for Energy Research, University of Nigeria, Nsukka

Clean energy is one of the main hurdles confronting rural com munities in the emerging world. Technologies that promote clean and sustainable energy include renewable energy sources, such as hydroelectricity, solar energy, wind energy, wave power, geothermal energy, artificial photosynthesis, and tidal power, and also technologies designed to improve energy efficiency and, bioenergy or biofuel. Biofuels include biodiesel (from plant oils), bioethanol (from plant sugar sources) and biogas (from organic waste materials), gasification (rice husks, saw dust, agricultural and organic wastes). Access to sustainable energy is essential for reducing poverty, malnutrition and hunger, improving health, increasing levels of literacy and education, and significantly improving the lives of women and children Renewable enrgy have the potential to deliver a number of benefits including reduction in green house gas emissions, improved air quality and increased energy. Sustainable energy is the sustainable provision of energy that meets the needs of the present without compromising the ability of future generations to meet their needs.

Keywords: biogas, gasification, biodiesel, ethanol, biomass, pyrolysis, pollution, fossil, clean


258

Abstract:0364

Effect of Solar, Electric oven Processing and smoking on the nutritional qualities of Trachurus trecae

Nkiruka Francisca Oparaku1, Chiamaka Francisca Nwaka2

1National centre for Energy Research, University of Nigeria, Nsukka2Zoology Department, University of Nigeria

Fish is highly perishable and prone to fungi, enzyme and microbial attack. Appropriate processing technologies is therefore, needed to enable maximal use of raw material. Reduction in post harvest losses of fish products could result in profitability of farmers. The effects of various processing methods (oven drying, solar drying, smoking) on the proximate composition and organoleptic properties of Trachurus trecae were investigated. The objectives of this work were to know the best processing methods that could improve organoleptic and nutritional characteristics of the fishes. Cunene horse Mackerel fish is the common name of Trachurus trecae. The fish is highly cherished as fish food especially by the low income earners. Methods of processing and storage and its duration generally causes depletion in essential nutrients and minerals in frozen and stored fin fishes.The result of the proximate composition of the fish species showed that, the protein content of Trachurus trecae processed by oven drying, solar drying and smoking were 45.71%, 53.23% and 21.14% respectively; the moisture contents were 33.50%, 17.21% and 19.21% respectively; the ash contents are 8.83%, 2.12% and 4.32% respectively; the carbohydrate contents are 6.413%, 3.12% and 2.65% respectively and the lipid the nutrient in the fish and equally prolong the shelf life of the fish products. Solar dryer could concentrating heat gradually on the product being dried by absorbing the sun energy.This study clearly indicates that solar is a good technology for fish processing and proximate values obtained could help the consumers in choosing fish based on nutritional values.

Keywords: Oven drying, solar drying, smoking, processing

Abstract:0366

Photopysical Properties of Oligothiophenes End-Capped With Thioxanthone Naphthalene

Emin Istif, Emel Karaboga, Demet Karaca Balta, Nergis ArsuYildiz Technical University, Chemistry Department

In parallel to the remarkable development of π-conjugated polymers as conductors and semiconductors, a renaissance of oligothiophenes was launched in 1989 by Garnier and Fichou. They realized that also shorter conjugated oligomers such as R-sexithiophene can be used as an active semiconductor materials in organic field-effect transistors (OFETs).

Later on, the implementation of structurally defined end-capped oligothiophenes in organic light emitting diodes (OLEDs) was demonstrated in 1993, and that of R-quinquethiophene and R-octithiophene in organic solar cells (OSC) was demonstrated in 1995.


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The advantages of oligothiophenes are that their physical properties can be easily tuned to the desired properties by changing the structure, for example, solubilizing chains, end-capping groups insertion of various functional groups and changing the oligomer lengths.

In this study, the synthesis and characterization of various oligothiophenes was achieved and Thioxanthone naphthalene was used as end-capping group for various oligothiophenes. These new oligothiophenes will give us opportunity to investigate the effect of end-capping groups. Beside of this, the effect of chain length of thiophene oligomers was also investigated. Ground and excited state photophysical properties like UV-Vis absorption and fluorescence emissions, fluorescence quantum yields, triplet lifetimes were investigated.

References;

[1]. H. Shirakawa, E.J. Lewis, A.G. McDiarmid, C.K. Chiang and A.J. Heeper, J. Chem. Soc. Chem. Commun., 1977, 578.[3]. D.K. Balta, N. Cetiner, G. Temel, Z. Turgut, N. Arsu, J. Of Photochem. And Photobiol. A-Chemistry, 2008, 199 (2-3), 316-321.[4]. Amaresh Mishra, Chang-Qi Ma and Peter Bauerle, Chem. Rev. 2009, 109, 1141-1276

Keywords: Thioxanthone, Oligothiophene, Photophysical Properties

Abstract:0367

Novel hybrid interfaces for photovoltaics by multi scale modeling of self-assembled molecular interlayers

Alessandro MattoniConsiglio Nazionale delle Ricerche, Istituto Officina dei Materiali (CNR-IOM) Cagliari

The conversion of solar energy directly into electricity by solar cells is a great opportunity to satisfy to the world energy demand of clean, cheap and renewable energy. The development of novel materials and interfaces for photovoltaics is a constantstimulus for the theoretical and computer-based research on novel interfaces and nanomaterials.

Theoretical modeling is an effective support to the development of materials and technologies and also a fascinating field of research that contributes to the diffusion of science and that is involving an increasingly large number of scientific groups worldwide.

Here, I will discuss the activity and the numerical methodologies developed at the Consiglio Nazionale delle Ricerche (CNR-IOM ) in Cagliari ( ITALY ) in the field of polymer based hybrid interfaces for photovoltaics. In particular, I will report some examples in the field of multi-scale modeling of organic/inorganic nano materials for solar cells[1] and on novel concepts that possibly driving the improvement of photovoltaic performances of hybrid interfaces through the use of self-assembled interlayers (such as pyridines [2,3], macrocyclic compounds [1]).

This work is funded by the Italian Institute for technology through IIT-SEED project POLYPHEMO and by Regione Autonoma della Sardegna.

[1] Melis C., et al. (2011). ACS NANO, vol. 5, p. 9639- 9647 [2] Canesi E.V., Binda M. (2012) ENERGY & ENVIRONMENTAL SCIENCE, vol. 5, p. 9068-9076[3] Malloci G. et al., (2013) Journal of Physical Chemistry C

Keywords: hybrid nanomaterials, theoretical modeling, polymers, photovoltaics


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Abstract:0368

Electronic / Substituents Influence On Imidazole Ring Donor-Acceptor Capacities Using 1H-Imidazo[4,5-f][1,10]

phenanthroline Frameworks

Abiodun Omokehinde Eseola1, Oluseyi Adepitan1, Helmar Gorls2, Winfried Plass2

1Department of Chemical Sciences, Redeemer’s University, Private Mail Bag 3005, Redemption Camp, Mowe, Ogun State – Nigeria.

2Institut für Anorganische und Analytische Chemie, Friedrich-Schiller-Universität Jena, Humboldtstraße 8, 07743 Jena, Germany.

Azole based materials are finding interest in solar and OLED research.1-4 However, useful understanding of the electronic character of the imidazole ring is necessary in order to fruitfully utilize the imidazole function in organic electronics. Eight imidazole-based compounds 4-methyl-2,6-bis(4,5-diphenyl-1H-imidazol-2-yl)phenol (A-dp), 2-(1H-phenanthro[9,10-d]imidazol-2-yl)phenol (B-2H), 5-methoxy-2-(1H-phenanthro[9,10-d]imidazol-2-yl)phenol (B-2H4M), 3-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol (C-3H), 2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)-4-methoxyphenol (C-2H5M), 4-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)-2-methoxyphenol (C-4H3M), 2-(2-methoxyphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (C-2M) and 2-(2,4-dimethoxyphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline (C-2,4M) were synthesized and characterized by elemental, spectroscopic and X-ray single crystal analyses. Two structures of A-dp were grown from ethanol and THF and revealed that A-dp crystallized in monoclinic (P2(1)/c) space group while A-dp.2THF crystallized in the triclinic (P-1) space group. A-dp.2THF was devoid of any kind of networks whereas absence of solvent adducts in the ethanol sample produced 1-dimentional single-stranded helixes.

Contrary to reported literature conclusion that 1H-imidazole alkylation should increasing the donor strength of the imidazole N-base, protonation-deprotonation equilibrium studies on the compounds suggest that push / pull of electron density on the 2-carbon of the imidazole ring by electron-rich / electron-withdrawing substituents is necessary to influence donor capacity of the N-base electrons. Furthermore, the notable increase in pKa,N: values due to ortho/para-directing methoxy substituents supports the conclusion that electron density push towards 2-position of the imidazole ring is important for improving N-base donor strengths. DFT calculation results using B3LYP/6-311+G level of theory were conducted to explore possible theoretical explanations.

Keyword: Intermolecular / intramolecular interactions; pKas; protonation-deprotonation, donor / acceptor strengths


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Abstract:0369

Battery Based Stand Alone Photovoltaic System

Mehmed Hamid Vishkasougheh1, Muhsin Mazman2, Mahbare Dogrusoz3, Bahadir Tunaboylu1, Bahadir Tunaboylu2, Ali Ata3

1Industrial Engineering, Istanbul Sehir University, Altunizade Mah. Kusbakısı sok, No: 27, Üsküdar, Istanbul, Turkey

2TÜBİTAK Marmara Research Center, Energy Institute, Gebze, Turkey3Department of MaterialScienceandEngineering,Faculty of Engineering,Gebze Institute of Technology, TR-

41400 Gebze/Kocaeli, Turkey

Abstract_ In this study an a-Si PV panel as electricity generator and Nano-phosphate LiFePO4 battery as the produced electricity storage system has been considered.In order to determine the real framework of this system weather and solar radiation of three cities in Turkey has been considered. The effect of temperature on the panels and its impact on efficiency has been investigated. A solar simulator has been used to determine the batteries performance in time frame of one year.

In this study a battery based stand alone photovoltaic system is considered. The generation system is contained of three panels of amorphous Silicon solar cells with efficiency of 7% and the storage system is contained eight packages of Nano phosphate LiFePO4 batteries with nominal voltage of 3.2 v.Each panel dimension is 1250*323*25 mm.

In order to come up with an estimate framework for this system, weather conditions in terms of solar radiations and temperature of three cities in Turkey is considered [1]. Istanbul, Ankara and Adana are the three cities, which are chosen according to the solar radiation amount in Turkey. I-V calculation is done for the system for the mentioned cities. Table I and IIare representing current and voltage calculations for three cities in each month.

The results showing this mobile package can be useful for lots of applications especially for remote areas that don’t have access to electricity. Furthermore, advantages like low weight, durability and cheap production price make this system more unique.

Keywords: Battery Based Stand Alone Photovoltaic System

Table-I

Max Current/Month Panel Current in Istanbul (A) Panel Current in Ankara (A) Panel Current in Adana (A)January 0.015361188 0.112991782 0.143317901February 0.221872377 0.298626852 0.328052971March 0.386631327 0.465635802 0.493711921April 0.552740278 0.613118634 0.639844753May 0.679796991 0.718849228 0.746025347June 0.70562311 0.764201466 0.810453704July 0.603942515 0.725599228 0.750975347August 0.542664159 0.562190278 0.609792515September 0.35702909 0.477785802 0.52628804November 0.188670139 0.267674614 0.317076852October 0.062963426 0.100215664 0.148717901December 0.002170293 0.006290741 0.063413426

Max working current for each city according to its solar radiation and temperature


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Table-II

Max Voltage/Month Panel Voltage in Istanbul (v) Panel Voltage in Ankara (v) Panel Voltage in Adana (v)January 29.38365706 28.65771059 28.3919213February 27.80613912 27.24045694 26.98471765March 26.54914977 25.95834259 25.7176783April 25.27708542 24.82141753 24.59582824May 24.29539965 24.00502106 23.77440677June 24.07986036 23.64429248 23.27351389July 24.85103183 23.92964606 23.71913177August 25.31674971 25.17156042 24.78570683September 26.73400336 25.82266759 25.426764November 28.03119271 27.44038553 27.03443194October 28.99780347 28.72752488 28.3316213December 29.4726735 29.45580278 28.99277847

Max working voltage for each city according to its solar radiation and temperature

Abstract:0384

Influence of the radio-frequency power on the physical and optical properties of plasma polymerized thin films deposited

by PECVD method

Manaa Chadlia1, Michael Lejeune2, Fayçal Kouki1, Habib Bouchriha1, Mohamed Benlahsen2

1Depatment of physics, Faculté des sciences de Tunis, Tunis, Tunisie2Depatement of Physics, pole sientifique Amiens, France

This study focuses on the changes of the microstructural, optical and electrical properties of thin films of organic polymers elaborated by Radiofrequency Plasma Enhanced Chemical Vapor Deposition (PECVD). Using cyclohexane as precursor gas, we studied the evolution of the deposited films as a function of RF power and of annealing temperature. Cyclohexane was chosen as the gas precursor because of its mechanical properties (high hardness). Nitrogen was used as doping gas during deposition in order to improve the electrical conductivity of the films.

The thin layers were deposited at different RF power (40W to 200W) keeping fixed other deposition parameters i.e. the gas flow and deposition time. The samples were then annealed in ambient atmosphere at 300 °C for one hour. A variety of different experimental techniques such as Fourier transform infrared spectroscopy (FTIR), optical UV-visible spectrophotometry and the electrical conductivity in the I(V) mode were used to characterize the films in their initial state (as deposited) as well as after annealing. The infrared measurements show that with “as deposited” state, the increase in the RF power induces an increase of the film density as a consequence of the increase in the density of Carbone double bonds (C=C) at the expense of CHX bonds. Regarding the electrical properties, the transverse mode measurements show an increase in the electrical conductivity measured at room temperature with increasing power. For all annealed samples we observed a systematic increase in the conductivity of our films.

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Optical measurements for the annealed samples show a decrease in the optical transmission with increasing RF power. This behavior is associated with an enhancement of the refractive index and therefore to the film densification. For the annealed samples we observed two different kinds of behavior: For the first group the layers deposited at low power (<= 120W), we noticed a decrease in the refractive index due to the decrease of density. On the contrary, for the films deposited at higher power there was an increase in the refractive index as a result of the increase of density. Furthermore, the first group of films deposited at low power becomes permanently transparent due to the annealing effect.

As a conclusion, the nitrogen doped cyclohexane thin films obtained by PECVD technique have interesting electro-optical properties with reduced internal stress.

Keywords: Cyclohexane, Plasma-Enhanced Chemical Vapor Deposition, FTIR, spectroscopy UV visible, electric properties.

Abstract:0387

Enhanced Capacitance of the Hydrogenated barium titanate film based metal–insulator–metal

Béchir Yangui1, Fathi Jomni3, Fadhel El Kamel2, Patrice Gonon4

1Laboratory for the Organization and Properties of Materials, University el Manar Tunis2Facuclté des Sciences de Gabès, Gabès University, Gabès, Tunisia

3Faculté des Sciences de Tunis, University el Manar Tunis4Microelectronics Technology Laboratory (LTM), Joseph Fourier University -Grenoble, France

Hydrogenated barium titanate film based metal–insulator–metal (MIM) systems show high dielectric constant and have therefore been proposed as solid state supercapacitors. Hydrogen was incorporated in the dielectric layer during the low temperature deposition process. An investigation of the electrical properties has revealed that hydrogen contributes to the conduction process as mobile ionic species as well as donor trap levels. At temperature higher than -30 °C protons contribute to the conduction mechanism as mobile ionic species. Such mechanism is thermally activated with 0.37 eV. In addition, protons have been proposed to induce n-type conductivity by generating shallow donor levels within the bandgap in titanates. Therefore, the trap we detect at 0.15 eV could be associated with such a donor level. Moreover, in disordered systems, protons were shown to engender hydrogen bonds in the structure. These bonds have to be related to a common feature for the oxides protonic conductors. As a result, the dielectric relaxation observed at temperature ranging from -75 to -30 °C could be related to the oscillation of the hydroxide bond due to the destruction of the hydro-gen bond. Activation energy for this process is around 0.25 eV.

Keywords: Hydrogenated barium titanate film, supercapacitors.


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Abstract:0389

Photoinduced polarons in bulk-heterojunctions: A detailed spectroscopic view to in-gap states

Philipp Stadler1, Jacek Gasiorowski1, Kurt Hingerl2, Matthew S. White1, Stefanie Schlager1, Helmut Neugebauer1, N. Serdar Sariciftci1

1Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University of Linz, Austria2Center for Surface- and Nanoanalytics, Johannes Kepler University of Linz, Austria

The bulk-heterojunction concept for organic solar cells brought up polythiophenes as standard donor part in terms of stability and efficiency. The thiophene family developed further with shrinking the band gap introducing co-polymer units – with an eye on enhancing the near infrared absorption. We picked P3HT and PBDTTT-c as common family prototypes representing the shift from visible to near infrared and we resolved the spectral features in detail within the band-gap. With our study we elucidate the polaronic states during photoexicitation – involving the strong vibronic contribution in conjugated polymers – and approaching closely the situation in a solar cell on operation. For this, we combined means of ellipsometry and ATR- FTIR and we characterized our thiophene candidates in the excited states in-situ. We present a detailed picture of the in-gap states with resolving each oscillator by a spectroscopic model and, furthermore, having confirmed the findings from photoexcited bulk-heterojunctions in persistently chemically doped thin-films.

Keywords: Photoinduced polarons in bulk-heterojunctions: A detailed spectroscopic view to in-gap states

Abstract:0392

Laser induced photocurrent approach to study the degradation of organic solar cells

Olena Kozlova1, Siegfried Bauer1, Reinhard Schwoediauer1, Markus Scharber2, Thomas Stockinger1

1Soft Matter Physics, Johannes Kepler University, Linz, Austria2LIOS, Johannes Kepler University, Linz, Austria

Organic solar cells have a promising future as a clean and cheap source of energy. However their stability is still a key issue. In this work we study the degradation of solar cells using Laser-Beam-Induced-Current (LBIC) technique. During the characterization a solar cell is illuminated spot by spot with a focused laser beam and the corresponding photocurrent is measured. With this method the regions with low efficiencies as well as different defects are observed. The LBIC technique also allows for characterization of metal electrodes by observing their discontinuities. Observing the evolution of the low efficiency regions and defects allows for better understanding of mechanisms of degradation of solar cells and comparing of stability of different kinds of solar cells.

Keywords: Laser induced photocurrent, degradation of solar cells, organic solar cells, P3HT:PCBM solar cells


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Abstract:0395

Chemistry of indigos – derivatizing a natural material for organic electronics

Zeynep Bozkurt, Eric Daniel Glowacki, Gundula Voss, Elisa Tordin, Niyazi Serdar Sarıçiftçi

Linz Institute for Organic Solar Cells (LIOS), Johannes Kepler University

Indigo and its derivatives are dyes and pigments with a long and distinguished history in organic chemistry. Recently, applications of this ‘old’ molecule as a functional organic building block for organic electronics applications have renewed interest in these molecules and their remarkable chemical and physical properties.

We have demonstrated that indigo and several of its derivatives show ambipolar charge transport in the range 1×10-2 – 0.5 cm2/Vs, with exceptional operational stability in air.1-4 Our recent research has focused on solution-based chemistry on the normally insoluble indigo, through the use of thermally-cleavable protection groups. Chemistry based on this protect-deprotect route enables enormous possibilities for the derivitization of indigo molecules. Using soluble protected dibromoindigos, we have succeeded in applying C-C coupling reactions such as Sonagashira and Suzuki couplings, allowing the attachment of π-conjugated units to the indigo core. Applying the protect-deprotect route also allows processing of the soluble precursors into films, followed by heating to regenerate the indigo pigment. Herein we discuss our recent progress on derivatizing the indigo molecule for enhanced performance in organic electronics applications.

Keywords: Organic electronics, Natural materials, sustainability

Abstract:0396

Photoelectrical performance in dye-sensitized solar cells with single-walled carbon nanotubes photoanodes

Mürsel Ekrem1, Emre Ünver2, Savaş Sönmezoğlu2, Ahmet Avcı3

1Department of Mechanical Engineering, Necmettin Erbakan University, Konya, Turkey2Department of Materials Science and Engineering, Karamanoğlu Mehmetbey University, Karaman, Turkey

3Department of Mechanical Engineering, Selcuk University, Konya, Turkey

Dye-sensitized solar cells (DSCs) have attracted considerable attention since they emerged as promising next-generation solar cells with low cost and high efficiency. Apart from the optimization of the nanostructure for light harvesting, an artificial design related to electron transport and recombination at the photoanode is particularly significant for efficient collection of photogenerated carriers. In this study, sandwich structure electrodes consisting of conductive single-walled carbon nanotubes (SWCNTs) and nanocrystalline TiO2 films are prepared as photoanodes of dye-sensitized solar cells (DSSCs). Photovoltaic parameters were found with a short-circuit photocurrent density (Jsc) of 3.42 mA cm-2, an open-circuit photovoltage (Voc) of 0.02 V, a fill factor (FF) of 0.25, and an overall efficiency (η) of 0.93%. The improved photoelectrical performance was attributed to the effective separation


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of photoinduced electrons and holes and the rapid transportation of photogenerated electrons of SWCNT. This sandwich structure electrode represents a promising approach for further improving the efficiency in DSSCs.

Keywords: Photoanodes, Single-walled carbon nanotubes, Dye-sensitized solar cells

Abstract:0397

The complex refractive index of conjugated polymers

Markus Scharber1, Jacek Gasiorowski1, Serdar N. Sariciftci1, Kurt Hingerl2

1Linz Institute for Organic Solar Cells, Johannes Kepler University Linz2Center for Surface and Nanoanalytics, Johannes Kepler University Linz

We have determined the complex refractive index of several different conjugated polymers using spectroscopic ellipsometry and found that the refractive index increases with decreasing the optical bandgap of the organic semiconductors. We will discuss the origin of this effect, its implications on the development of high performance absorber materials and light managements schemes for organic solar cells.

Keywords: organic solar cells power conversion efficiency semiconductors optical properties

Abstract:0399

New Porphyrin -Based Spectrophotometric Sensor For Ago Detection

A. Palade1, G. Fagadar-Cosma2, A. Lascu1, I. Creanga1, M. Birdeanu3, V. Barsan4, E. Fagadar-Cosma1

1Institute of Chemistry Timisoara of Romanian Academy, 24 M. Viteazu Ave, 300223-Timisoara, Romania2”Politehnica” University of Timisoara, Faculty of Industrial Chemistry and Environmental Engineering,

Victoriei Square 2, 300006-Timisoara, Romania,3National Institute for Research and Development in Electrochemistry and Condensed Matter, 1 Plautius

Andronescu Street, 300224-Timisoara, Romania4IFIN-HH, Magurele-Bucharest 077125, Romania

An approach to obtain silver colloids of different sizes by reduction of silver nitrate with sodium citrate in bare form and stabilized with polyethyleneglycol was intended in the purpose of developing new hybrid porphyrin-based materials with extended opto-electronic properties. The plasmons were comparatively analyzed by UV-vis and AFM investigations. Unexpectedly, the stabilized colloid tends to aggregate giving rise to honeycomb like architectures.

A new complex based on 5-(4-carboxy-phenyl)-10,15,20-triphenyl-porphyrin and freshly synthesized silver colloid was obtained and can be further used as a new optical sensor for Ag0 detection in very


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small concentrations (2.5x10-9 M to 0.82x10-7 M), broadening the known detectable concentration range for rare metals and improving their recovery.

The investigation of the behaviour of Ag+ ions towards the same bare porphyrin led to obtaining of Ag (II) 5-(4-carboxy-phenyl)-10,15,20-triphenyl-porphyrin as a result of disproportionation of Ag(I) ions.

Keywords: metal-organic hybrid nanomaterial, carboxy-functionalized porphyrin, silver colloid, UV-vis absorption, AFM

Abstract:0400

Crystalline Sodium Tantalates Produced via Hydrothermal Synthesis for Photocatalytic Hydrogen Production

Tobias Grewe, Harun TüysüzMax-Planck Institut für Kohlenforschung, Mülheim an der Ruhr, Germany

The world-wide concerns about fossil fuel shortage and increasing carbon dioxide

emission that causes the global warming force society to find alternative renewable and clean energy sources. Among the alternatives, solar energy has attracted considerable attention because of its potential to provide huge amounts of the required energy. Solar energy can be utilized to produce hydrogen as solar fuel from photoelectrolysis or photocatalytic water

splitting. Sodium tantalates have shown promising catalytic activities for the generation of H2 under irradiation even without any co-catalyst.[1] Herein, we report the preparation of a series of NaTaO3, Na2Ta2O6 and composite sodium tantalates. The crystal structure, band gap, morphology and textural parameters of the samples can be controlled via a feasible hydrothermal route by changing the pH and reaction time. At lower pH pyrochlore-type Na2Ta2O6 with an average particle size of around 27 nm was synthesized. By slightly increasing the alkali concentration, another Na2Ta2O6 sample with an average particle size of

15 nm and higher surface area was obtained. Further increasing the alkali concentration produces a series of composite materials based on a mixture of Na2Ta2O6-NaTaO3. In addition, large NaTaO3 cubes were prepared at very high alkali conditions. Pyrochlore-type sodium tantalate with the smallest particle size showed the highest activity for water-splitting by reaching a H2 production rate of over 60 mmol/h/gcat and excellent material stability.

Moreover, the photocatalytic activity of NaTaO3-Na2Ta2O6 composite samples showed higher activity than Na2Ta2O6 with comparable surface areas, which was correlated to the junction between two crystalline phases of sodium tantalate. These results show that nano crystalline sodium tantalates prepared by hydrothermal route have great potential in renewable energy development due to their simple preparation process and high photocatalytic activity.[2]

[1] H. Tüysüz, C. Chan, Nano Energy 2013, 2, 116-123.

[2] T. Grewe, K. Meier, H. Tüysüz, 2013, submitted.

Keywords: Crystalline Sodium Tantalates Produced via Hydrothermal Synthesis for Photocatalytic Hydrogen Production


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Figure 1.

SEM image of Na2Ta2O6 photocatalyst (a) and photocatalytic activity for H2 production (b).

Abstract:0401

Synthesis And Characterization of A Water-Soluble Silicon Phthalocyanine Complex Designed For Solar Hydrogen

Production Powered By Red Light

Canan Uslan1, Canan Uslan2, Kerstin T. Oppelt1, Lorenz M. Reith1, Behice Şebnem Sesalan2, Günther Knör1

1Institute of Inorganic Chemistry, Johannes Kepler University, 4040 Linz, Austria.2Department of Chemistry, Istanbul Technical University, Maslak 34469, Istanbul, Turkey.

The development of novel photosensitizers with optimized properties is an important branch of solar energy research [1]. For the construction of an “artificial leaf” based on molecular components, it is necessary to mimic the key-properties of the natural light-harvesting antenna pigments and to replace the catalytic function of the redox-active components present in photosynthetic reaction centers.

In this context, the detailed photophysical and photochemical characterization of a novel water soluble silicon phtalocyanine complex will be presented [2,3] with a special focus on photoinduced electron transfer processes relevant for solar fuel production [3].

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[1] G. Knör, U. Monkowius, Adv. Inorg. Chem., 2011, 63, 235.[2] C. Uslan, B. Ş. Sesalan, Inorg. Chim. Acta 2013, 394, 353.[3] C. Uslan, K. T. Oppelt, L. M. Reith, B. Ş. Sesalan, G. Knör, Chem. Commun. 2013. DOI:10.1039/C3CC44674C.

Keywords: Synthesis And Characterization Of A Water-Soluble Silicon Phthalocyanine Complex Designed For Solar Hydrogen Production Powered By Red Light

Figure

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Abstract:0406

Pt-Al2O3 nano-structured selective absorbers for high temperature photothermal concentrated solar power

applications

Z.Y. Nuru1-2, B.D. Ngom1-2,3 , Y. Azoumah 1-2, 4, I. Youm1-2, 5, C. Sella1-2,6, S. Rahman1-2,7, S. Berthier1-2, 7, M. Maaza1-2,

1-UNESCO Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk ridge, POBox 392, Pretoria-South Africa,

2- Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1Old Faure road, 7129, POBox 722, Somerset West, Western Cape Province, South Africa.

3-Physics Dept., University of Cheikh Anta Diop of Dakar, Dakar Fann, South Africa4-Solar Energy and Energy Saving Laboratory (LESEE), Institut International d’Ingénierie de l’Eau et de

l’Environnement (2iE), 01 BP 594 Ouagadougou Burkina Faso5-Centre d’Etudes et de Recherches sur les Energies Renouvelables (CERER) Rte du Service

Géographique (HB-87) X Rue HB-478, Hann Bel-Air B.P. 476, Dakar-Senegal6-Photonics Centre, MASCIR, Rabat-Morocco

7-Institut des Nanosciences, Paris VI, Jussieu, Paris-France,

Summary

In the recent years Concentrated Solar Power (CSP) has become a small but increasing integral part of the electricity supply of many countries of the world. CSP technology uses high temperature solar heat to operate engines. It offers unique features such as the possibility of a sustainable base load electricity supply and the possible hybridization with a simultaneous use of the engine waste heat for secondary applications such as desalination or as booster units in established coal energy generation based stations. Therefore this technology can help in solving two of the main global problems especially occurring in countries belonging to the desert belt of the world or with high DNI geographical landscape. South Africa is currently embarking in defining its solar energy road map and implementation of its solar energy strategy by 2015. This contribution reports recent experimental results obtained on high temperature Pt-Al2O3 selective solar absorbers engineered and approved in

terms of CSP requirements and durability as well as lifetime. The optimized Pt-Al2O3 selective solar

absorber coatings exhibit the following parameters: (i) high solar absorptance of about a ≈ 0.90-0.98, (ii) low thermal emittance ε < 0.08 at T <650 ºC, low reflectance (ρ ≈ 0) at λ <= 3µm with a high reflectance (ρ≈1) at λ >= 3µm at T<= 650°C in air, and are thermally stable up to 700 ºC, in air, with improved durability.

Keywords: Solar absorbers, Photothermal conversion, Thermal stability, Cermets, Nano-particles, Platinum, Alumina.


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Abstract:0407

Indigenous African dyes based Nitrogen greenly doped titania Gratzel Solar Cells

A. Dialo1-2, S. Zongo1-2, B.D.Ngom1-2,3 , Y.Azoumah 1-2, 4, I.Youm1-2, 5, N. Robertson1-2, 6, W. Soboyejo1-2, 7, M. Maaza1-2

1- UNESCO Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk ridge, POBox 392, Pretoria-South Africa,

2- Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1Old Faure road, 7129, POBox 722, Somerset West, Western Cape Province, South Africa.

3-Physics Dept., University of Cheikh Anta Diop of Dakar, Dakar Fann, South Africa4-Solar Energy and Energy Saving Laboratory (LESEE), Institut International d’Ingénierie de l’Eau et de

l’Environnement (2iE), 01 BP 594 Ouagadougou Burkina Faso5-Centre d’Etudes et de Recherches sur les Energies Renouvelables (CERER) Rte du Service

Géographique (HB-87) X Rue HB-478, Hann Bel-Air B.P. 476, Dakar-Senegal6- Chemistry Dept., University of Edinburgh, King’s Buildings, West Mains Road, Edinburgh EH9 3JJ, UK

7-Nelson Mandela African University of Science & Technology, Km 10, Airport road, Abuja-Nigeria.

A Gratzel DSC unit with a Ru based sensitizer has a dye uptake of ca. 10-7 mol cm-2 (layer thickness d=10 mm), which corresponds to 1 g of dye per m2. Hence the price of the dye per Watt peak “Wp” can be estimated using the equation: Ptotal =Sc. Mdye. Pmass / IAM1.5 x η, where Ptotal is the price per Wp, Sc is the coverage surface, Mdye is the molecular mass of the dye (g mol-1), Pmass is the price per mass (€ g-1) while IAM1.5 is the light intensity of an AM 1.5 (Wm-2) sun-simulator with η being the efficiency of the DSC. For ruthenium based DSCs, Pmass is strictly dependent on the production scale. Actually its commercial price is estimated to be ~300 € g-1 but, large scale production, could reduce it in the future to a cost level of about 30 € g-1 resulting in a Ptotal of ~0.8 € per Wp. So the cost of the dye for a DSC based panel of 3 kWp would be about ~2400 €. Even, for organic dyes, the production costs and the Ptotal are estimated similar to ruthenium dyes. Moreover, the actual production is still far to satisfy large scale demand. Besides the cost related matter (Ru based dyes count for the 10–15% the total expense of DSCs), indirect environmental charges, due to the chemical byproducts disposal, need to be considered. Natural pigments which consist of chlorophylls, anthocyanins or betalains could be exploited as sensitizer in DSCs. This poster reports on the photonics properties of Hibiscus Sabdarifa dye extract and their integration in N doped nano-TiO2 /graphene electrodes based DSCs.

Keywords: Dye solar cells, Sentisizer, Natural dyes, Hibiscus Sabdarifa, Nano TiO2, Graphene electrodes,


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Abstract:0408

Smart hybrid thermochromic VO2 based nano-coatings for solar heat management and air conditioning minimization

B.M. Itani1-2, L. Mathevula1-2, B.D.Ngom1-2,3 , G. Merad1-2, 4, K. Bouziane1-2, 5, A. Gibaud1-2, 6, M. Maaza1-2

1- UNESCO Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk ridge, POBox 392, Pretoria-South Africa,

2- Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 Old Faure road, 7129, POBox 722, Somerset West, Western Cape Province, South Africa.

3-Physics Dept., University of Cheikh Anta Diop of Dakar, Dakar Fann, South Africa4- Unité de Recherche Matériaux et Energies Renouvelables, Univ. de Tlemcen, B.P. 119, 13000 Tlemcen,

Algeria.5-Centre des Energies Renouvelables, Universite Internationale de Rabat, Rabat-Morocco

7-Physiscs Dept., Universite du Maine, Le Mans-France.

Due to its singular Mott type 1st order transition, VO2 nano-structured coatings deposited onto glass substrates exhibit a unique reversible infrared modulation triggered by an external temperature stimuli. In the infrared range, equivalent to solar heat, such VO2 nano-coatings are optically transparent and optically opaque for Infrared Radiations “IR i.e solar heat” below and above Tc~ 68ºC, respectively. Such a behavior is known as thermochromism. Once doped with tungsten, such a transition temperature can be reduced to Tc ~25ºC and consequentially, W:VO2 nano-coatings are active under normal atmospheric solar heat radiations. Therefore, these W:VO2 nano-coatings deposited onto the glass windows of cars and/or buildings can be used to regulate solar-radiations induced heat. Therefore, this family of VO2 based smart windows will act as a self-control air conditioning component. This solar induced heat regulation and self-management offered by the W:VO2 based windows, is not only green but very effective energy saving technology in the vital and growing air conditioning sector. It could play a pivotal role in view of the current global warming trend and energy savings. This contribution reports on solar heat regulation of relatively large W doped thin coatings of VO2 synthesized by a cost effective process.

Keywords: Mott transition, Vanadium dioxide, Thermochromism, Solar heat regulation, Air conditioning, W doping.


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Abstract:0409

Growth dynamic of self assembled polymerized C60 nanorods for organic solar cells applications

C. Mtshali1-2, P. Sechogela1-2, T. Kerdja1-2,3, M. Izzerouken1-2,4, H. Haneda1-2,5, M. Maaza1-2

1-UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Muckleneuk ridge, POBox 392, Pretoria-South Africa,

2-Nanosciences African Network (NANOAFNET), iThemba LABS-National Research Foundation, 1 OldFaure road, Somerset West 7129, POBox 722, Somerset West, Western Cape Province, South Africa.

3-Centre de Development des Technologies Avancees, Baba Hassan, Algiers-Algeria4-Centre de Recherche Nucléaire de Draria (CRND), BP.43, Sebbala, Draria, Algiers, Algeria5-National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki, 305-0044, Japan

Since its discovery by Kroto et al, C60 and other fullerene derivatives based nanomaterials have opened several technological opportunities in various fields including photonics, electronics, sensing and specifically solar energy,….. Indeed, due to its donor and acceptor properties, C60 has been a key component in the 3rd generation organic solar cells. As in the case of Gratzel dye solar cells where the

1-D tubular shape anisotropy of TiO2 nanotubes has been proven to play an effective role in enhancing the carrier free mean path and hence minimizes the e-h recombination, C60 nanorods could play a similar functionality in the organic cells. Such tubular 1-D C60 nanorods can be generated through a polymerization process. One can distinguish 3 methods of synthesis of the highly shape anisotropic C60 nanorods: (i) laser irradiation or UV-photo-polymerization of C60, (ii) high pressure-high temperature of C60, and (iii) catalytically assisted growth, as well as (iv) the cost effective Rao-Miyazawa liquid-liquid interfacial methodology. This later is a room temperature low pressure strategy involving a thermodynamically slow dynamic driven growth process. It consists of interfacing a solution of C60 in C6H5CH3 and CH3CHOHCH3 allowing a C60 dimerization process (formation of germs of C120) inducing a formation of 1-D chains of C60 which in its turn give birth to long longitudinal nano-wires type crystals. This contribution reports on the growth dynamics governing the self-assembly mechanism of the C60 nanorods via Wiener’s method. The average value of the interfacial diffusion coefficient Dint governing the growth of the C60 nanorods, is deduced to be of the order of 3.32 10-6 m2 /s.

Keywords: Organic solar cells, C60, Self-assembly, Growth dynamic, C60 nanorods, Shape anisotropy.


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Abstract:0410

Economic and Energetic analysis for optimizing the length of flat- plate solar air heating collectors

Nassar Yasser Fathi, Mohamed Alamen SharifSolar Energy Laboratory, Faculty of Engineering & Technology – University of Sebha

One dimensional steady state mathematical model has been developed for study the thermal behavior of two types of flat-plate solar air heating collectors. The model allows demonstration the influence of the collector’s dimension leading to optimize the length of the collector. The model implemented numerically using finite-difference technique with mass flow rate of 0.01 kg/s per unit area of solar collector and the incident solar radiation equal to 900W/m2. The analysis has been done for a large range of areas. Illustrative results such as the temperatures of the

components of the collectors (glass cover, absorber plate, air flowing through the collector and the rear plate), efficiency and useful heat extracted from the collector are graphically presented. The obtained results from both the energetic and economic analysis showed that, for the first type of the flat-plate solar air heating collector, the optimum length is 4.05 meters, moreover, it dawdles its energy collected past for lengths greater than 6 meters. There is no optimum length for the second type, but there is no much energy gain for lengths greater than 6 meters anyhow, the economic analysis showed that the length must be greater than 2.5 meters for both types of collectors.

Keywords: Economic and Energetic analysis for optimizing the length of flat- plate solar air heating collectors

Abstract:0414

Tin Chlorin, A Stable Chlorophyll-Like Sensitizer For Red Light Driven Artificial Photosynthetic Nadh-Formation

Kerstin T. Oppelt1, Eva Wöß1, Martin Stiftinger2, Wolfgang Schöfberger1, Günter Knör1

1Institute of Inorganic Chemistry, Johannes Kepler University, 4040 Linz, Austria.2Institute of Analytical Chemistry, Johannes Kepler University, 4040 Linz, Austria.

The accumulation and chemical storage of reduction equivalents with a functional molecular model of Photosystem I is presented. A robust water soluble tin porphyrin sensitizer and a rhodium-based redox catalyst are coupled to mediate regioselective two-electron reduction of NAD+ to NADH driven by red light.

We report on the reaction of NAD+ to NADH [1-4] using a water soluble tin chlorin sensitizer in a photochemical system with [Rh(bpy)Cp*H2O]2+ [5,6] as a co-catalyst as well as the application of this system for the enzymatic reduction of ketones and aldehydes to alcohols. This process can be considered as a simple biomimetic model reaction for the P700 to ferredoxin-NADP+ reductase sequence occurring in natural photosynthesis.


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[1] J. Kim, Chem. Comm. 2011, 47, 10227. [2] A. Harriman, Journal of Photochemistry 1985, 29, 139. [3] J. Handman, Nature 1984, 307, 534. [4] K. Kalyanasundaram, Photochemistry of polypyridine and porphyrin complexes, Academic Press London: London, 1992. 462. [5] E. Steckhan, Organometallics 1991, 10, 1568. [6] F. Hollmann, J. Mol. Cat. B. 2003, 19, 167.

Keywords: Tin Chlorin, A Stable Chlorophyll-Like Sensitizer For Red Light Driven Artificial Photosynthetic Nadh-Formation

Figure

Abstract:0417

PbS quatum dots in hybrid inorganic-organic tandem solar cells

M. J. Speirs1, C. Piliego1, L. Protesescu2, M. Kovalenko2, M. A. Loi1

1Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, Groningen, 9747 AG. The Netherlands

2ETH Zurich, Rämistrasse 101, 8092 Zurich, Switzerland

Inorganic semiconducting quantum dots (QDs) are a promising class of materials in the field of solution-processable photovoltaics. They possess high absorption coefficients and high mobility compared to organic materials. Moreover, their optical properties can be tuned by varying the crystal size. This makes them prime candidates for use in various device structures including tandem cells, where using materials with complementary absorption ranges is critical to achieving full spectral coverage and current matching between the tandem subcells.

PbS QDs have been reported to yield highly efficient solar cells and recently we have achieved exceptional power conversion efficiencies of 5.2% in Schottky devices[1,2]. Using this highly efficient material in more sophisticated device structures and in combination with high-performance polymer-fullerene blends should yield even higher efficiencies. Hybrid inorganic-organic structures such as these are still a very much unexplored, yet promising class of solar cells. In this work we will present our progress in the fabrication of tandem solar cells featuring PbS quantum dots in combination with polymer-fullerene


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blends, successfully implementing a novel metal-metaloxide combination as interlayer, with which we obtain a Voc exceeding 90% of the sum of the Voc’s of the subcells and a PCE of 2,2%.

[1] Szendrei, K. and Gomulya, W. and Yarema, M. and Heiss, W. and Loi, M. A., Appl. Phys. Lett. 97, 203501 (2010); doi: 10.1063/1.3518067.[2] Piliego, C and Protesescu, L and Bisri, S.Z. and Kovalenko, M.V. and Loi, M.A., Energy Environ. Sci. (accepted)[3] Piliego, C. and Manca, M. and Kroon, R. and Yarema, M. and Szendrei, K. and Andersson, M.R. and Heiss, W. and Loi, M.A., J. Mater. Chem., 2012,22, 24411-24416

Keywords: PbS quatum dots in hybrid inorganic-organic tandem solar cells

Abstract:0418

Tracing Charge Transfer State in Polymer-Fullerene Bulk-Heterojunctions

Marianna Manca1, Claudia Piliego1, Ergang Wang2, Mats R. Andersson2, Andrea Mura1,3, Maria A. Loi1

1Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, Groningen, 9747 AG, The Netherlands

2Department of Chemical and Biological Engineering/Polymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden

3 Dipartimento di Fisica, Universita degli Studi di Cagliari, I-09042 Monserrato, CA, Italy

The charge transfer state (CTS) is an intermediate excited state at the interface between two intermixed materials, in general a polymer (donor) and a fullerene derivative (acceptor). In this state the exciton couple, generated after photo excitation, is weakly coulombically bounded: the electron has been already promoted to the next acceptor molecule but is still correlated to the parent hole in the donor.

The CTS can be depicted as an intermediate step between the photogenerated excitons and the generation of free charges. Therefore a better understanding of the CTS dynamics in polymer-fullerene blends is fundamental due their relevance in the organic solar cell working mechanism [1].

Evidences of the presence of CTS in polymer-fullerene blends have been provided combining optical absorption, steady-state photoluminescence (PL) spectroscopy and time resolved measurements [2-4].

However, to fully understand the nature of this state its spatial localization in the polymer-fullerene blends has to be studied.

In this work by coupling a confocal laser scanning microscopy (CLSM) to spatially resolved photoluminescence signals, we can select and excite different regions of the sample, correlating local sample composition to the photoluminescence spectrum. In this way we are able to probe spectroscopically the presence of the CTS, providing at the same time, a spatial resolution of the CTS position in the blend. Our experiments point out that the CTS is mainly localized in the regions where the two materials are more intimately mixed.

*Marianna Manca, Claudia Piliego, Ergang Wang, Mats R. Andersson, Andrea Mura and Maria Antonietta Loi, “Tracing Charge Transfer States in Polymer-Fullerene Bulk-Heterojunctions” J. Mater. Chem. A, 1, 7321-7325 (2013).


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[1] Markus C. Scharber, Christoph Lungenschmied, Hans-Joachim Egelhaaf, Gebhard Matt, Mateusz Bednorz, Thomas Fromherz, Jia Gao, Dorota Jarzab and Maria A. Loi ”Charge transfer excitons in low band gap polymer based solar cells and the role of processing additives” Energy Environmental Science 4, 5077 (2011)]. [2] Arne C. Morteani, Richard H. Friend and Carlos Silva “Exciton trapping at heterojunctions in polymer blends” The Journal of Chemical Physics 122, 244906–244906–7 (2005). [3] Maria A. Loi, Stefano Toffanin, Michele Muccini, Michael Forster, Ulrich Scherf, and Markus C. Scharber “Charge Transfer Excitons in Bulk Heterojunctions of a Polyfluorene Copolymer and a Fullerene Derivative” Advanced Functional Materials 17, 2111–2116 (2007). [4] Claudia Piliego e Maria A. Loi “Charge transfer state in highly efficient polymer–fullerene bulk heterojunction solar cells” Journal of Materials Chemistry 22, 4141 (2012).

Keywords: Tracing Charge Transfer State in Polymer-Fullerene Bulk-Heterojunctions

Abstract:0420

Natural Pigments for Electrochemical Capture and Release of Carbon Dioxide

Dogukan Hazar Apaydın, E. Glowacki, E. Portenkirchner, N. S. SarıçiftçiLinz Institute for Organic Solar Cells (LIOS), Institute of Physical Chemistry, Johannes Kepler University Linz,

Austria

With the increase industrialization across the globe the amount of CO2 emission increased rapidly. The main sources are fosil fuel power plants, fuel processing plants and other industrial factories. Sudden release of CO2 from these sources to the atmosphere cause an increase in Greenhouse effect. Several groups in academia are trying to reduce CO2 for the use in solar fuel applications. However before reducing it one should consider how to capture CO2. The capture of CO2 is usually in industrial scale and industrial processes use solvents, solid sorbents or membranes for the capture of CO2. All of these systems either require high amount of solvents or high purity oxygen gas resulting in an increased but necessary cost[1].

Another method is the electrochemical capture of CO2. However, this requires the use of some high temperature (400-650oC) processed materials like molten salts or special Platinum, Lithium/Zirconium compounds[2-4].

Recently, air stable natural pigments were proven to have high charge carrier mobility due to their strong intermolecular interaction resulting in π-stacking and crystalline ordering[5]. These molecules also go into two-electron reduction and oxidation process upon applied potentials.

In this study, Quinacridone and poly(6,6-dithieno indigo) were utilized as CO2 capturing compounds in the presence of CO2 upon applied potential. Aformentioned compounds were deposited on ITO slides either by thermal evaporation (Quinacridone) or electrochemical polymerization. These molecules tend to release absorbed CO2 via electrochemical oxidation as well as mild heating conditions (120-150oC).

References:

[1] Carbon Dioxide Capture and Storage, Ingovernmental Panel on Climate Change, Cambridge University Press, 2005


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[2] E. Ruiz, D. Cillero, A. Morales, G. S. Vicente, G. Diego, P. J. Martinez, J. M. Sanchez, Electrochimica Acta, dx.doi.org/10.1016/j.electacta.2013.04.146[3] S. Camparani, P. Chiesa, G. Manzolini, International Journal of Greenhouse Gas Control, 2010, 4, 441-451[4] Y. Duan, Journal of Renewable and Sustainable Energy, 2011, 3, 013102[5] E. D. Glowacki et al, er. 2013, 25, 1563–1569

Keywords: Natural Pigments for Electrochemical Capture and Release of Carbon Dioxide

Abstract:0421

Effect of varying one moiety in the backbone of thiophene containing PPE-PPV conjugated copolymers on charge carrier

mobility and photovoltaic performance

Getachew Adam Workneh1,2, Teketel Yohannes1, Alberto Montaigne2, Christoph Ulbricht2, Matthew White2, Niyazi Serdar Sariciftci2, Daniel A. M. Egbe2

1Addis Ababa University, Faculty of Science, Department of Chemistry,PO.Box 1176, Addis Ababa, Ethiopia.2Linz Institute for Organic Solar Cells (LIOS), Physical chemistry, Johannes Kepler University Linz,

Altenbergerstrasse 69, 4040 Linz, Austria.

By varying one moiety with thiophene, bithiophene or 3,4-ethylenedioxythiophene at the X position in the thiophene containing poly(p-phenylene-ethynylene)-alt-poly(p-phenylene-vinylene)s (PPE-PPV) copolymers with a general structural design (Ph-C≡C-X-C≡C-Ph-CH=CH-Ph-CH=CH-) bearing identical side chains at the phenylene rings were synthesized. The effect of this structural alteration on the properties such as photophysics, electrical, charge carrier mobility and morphology of the materials and its impact on their photovoltaic performance were studied. Due to the functionalization with octyloxy and 2-ethylhexyloxy side chains these polymers are well soluble in common organic solvents such as chloroform, chlorobenze and dichlorobenzene. The copolymer with a single thiophene ring at the X positions showed the highest VOC of 930 mV and the copolymer with a bithiophene unit at X position showed the highest short-circuit current density and charge carrier mobility. Where as the copolymer with 3,4-ethylenedioxy thiophene showed the lowest photovoltaic performance.

Keywords: Effect of varying one moiety in the backbone of thiophene containing PPE-PPV conjugated copolymers on charge carrier mobility and photovoltaic performance

Figure 1 Figure 2


278

Abstract:0425

Fabrication and a complete structural, optical and electrical analyses of porous Ge nanostructures embedded in a

dielectric matrix

B. Altuntas1,2, S. Ilday2,3, R. Turan1,2 , S. Mirabella4, S. Cosentino 4, R. Raciti4, A. Terrasi 4

1Department of Physics, Middle East Technical University, 06800, Ankara, TURKEY2Center for Solar Cell Research and Applications (GÜNAM), Middle East Technical University, 06800,

Ankara, TURKEY3Department of Micro and Nanotechnology, Middle East Technical University, 06800, Ankara, TURKEY

4Dipartimento di Fisica e Astronomia and CNR-INFM, MATIS, Università di Catania, I-95123, Catania, ITALY

The primary goal of this thesis is to synthesize porous Ge nanostructures embedded in a dielectric matrix and perform a complete structural, optical and electrical characterization. Ge nanostructures can be a good candidate for use in third-generation solar cells, since they are alternative to Si nanostructures owing to their potentially higher photon conversion efficiencies. So far, most of the research is focused on the use of quantum dot structures in photovoltaic applications, although they provide quantum confinement of excitons, their drawback is the difficulties in electrical connection, which relies on tunneling probability through the dielectric matrix. As an alternative, we propose fabrication of porous Ge nanostructures embedded in a dielectric matrix via magnetron-sputtering technique, which is an interconnected Ge nanocrystal network where the electrical connection does not require any tunneling mechanism. We also suggest a way to preserve the quantum confinement effect by carefully tailoring the Ge content and engineering the structure of dielectric matrix.

Keywords: Fabrication and a complete structural, optical and electrical analyses of porous Ge nanostructures embedded in a dielectric matrix: Possibility of third-generation solar cell applications

Abstract:0426

Optimization of Metal Assisted Texturing for Multi Crystalline Si Solar Cells

Fırat Es1,2, Mustafa Kulakci1,2, Rasit Turan1,2

1The Center for Solar Energy Research and Applications (GUNAM), Middle East Technical University, Dumlupinar Blvrno: 1, 06800 Ankara, Turkey

2Department of Physics, Middle East Technical University, Dumlupinar Blvr no: 1, 06800 Ankara, Turkey

Processes putting low stress on wafers such as electroplating and high tech handling equipment enable the usage of thinner wafers for crystalline silicon cell production. Usage of thinner wafers will decrease the final cost per watt of the produced cell by decreasing the amount of silicon used per cell. However, thin wafers suffer from low light absorption which results in a decrease in short circuit current density. Thus, surface texturing is becoming one of the most crucial steps in the thin crystalline silicon solar cell fabrication. Mono-crystalline silicon shows excellent light trapping and low reflection properties when textured with alkaline solutions due to its anisotropic etching properties. However, for multi-


279

crystalline cells, texturing is accomplished by isotropic etching of the surface, which results in inferior light trapping and reflection properties to mono-crystalline cells.

In this study, metal assisted etching technique has been optimized to be applied for multi-crystalline silicon solar cell texturing. Since electroless etching is a solution based method, it is easily applicable to the industrial large area process. Also reflection properties as well as cell parameters of the cells could be adjusted by changing parameters of etching solution and duration to find the optimum performance for multi-crystalline silicon solar cells.

Keywords: Optimization of Metal Assisted Texturing for Multi Crystalline Si Solar Cells

Abstract:0427

Single Step Doping for Selective Emitter Crystalline Si Solar Cells

Emine Hande Ciftpinar1,2, Fırat Es2,3, Olgu Demircioğlu2,3,Mete Gunoven2,3, Rasit Turan1,2,3

1Department of Physics, Middle East Technical University, Dumlupinar Bulvari no:1 , 06800 , Ankara Turkey 2The Center for Solar Energy Research and Applications (GÜNAM), Middle East Technical University,

Dumlupinar Bulvari no:1 , 06800 , Ankara Turkey 3Micro and Nanotechnology Graduate Program, Middle East Technical University, Dumlupinar Bulvari no:1

, 06800 , Ankara Turkey

Selective emitter cell technology is one of the recent approaches to reach higher efficiency values on crystalline Silicon solar cells. In selective emitter design, the region under the front metal contact is heavily doped for lower contact resistance, while the remaining part of the emitter is lightly doped for higher carrier lifetime. Thus, emitter saturation current reduces, open circuit voltage of the cell increases and blue response of the cell improves. Selective emitter cells could be processed by several different methods such as; etch back process, laser doping, ion implantation, doping paste utilization and masked diffusion. In all these methods (except etch back process), two diffusion steps are required to obtain the desired doping profiles for selective emitter configuration. In the case of etch back approach, a critical wet etching step should be carried out for the same purpose. These additional process steps make the production more complex, less reliable and also increase the overall cost. An alternative approach is based on diffusion through a patterned dielectric layer by a single step doping. The dielectric layer under the metal fingers is removed by laser scribing so that the dopant concentration beneath front metallization fingers becomes higher compared to the rest of front surface area.

In this work, the single step doping through laser grooved oxide layer has been studied. Oxide thickness, doping, laser scribing and alkali cleaning steps have been optimized to reach the sheet resistance values needed for an efficient cell design. c-Si solar cells have been fabricated using that new selective emitter approach. And depending on the observed improved blue response in the external quantum efficiency(EQE), it was deduced that cells based on that new selective emitter structure could be used to reach higher conversion efficiency values compared to standard cell design.


280

Explanatory Pages

In this study, both selective emitter and reference cells were processed simultaneoulsy where additional oxidation, laser scribing and corresponding cleaning steps were applied for selective emitter cells.

Figure 1: Cell Performance of a Selective Emitter and a Standard Solar Cell

As shown in Figure 1, selective emitter cell resulted in better current than the standard cell. Moreover, although standard cells gave slightly higher efficiency values compared to selective emitter cells, expected blue response improvement could be observed as shown in Figure 2. Also; relatively lower efficiency values was attributed to the misalignment problems during metallization step.

Figure 2: External Quantum Efficiency Measurements


281

Abstract:0429

Paper – a new material for organic solar cells

Lucia Nicoleta Leonat1, Matthew White1, Eric Daniel Glowacki1, Markus Scharber1, Tino Zillger2, Mozzam Ali2, Arved Hübler1, Niyazi Serdar Sarıçiftçi1

1Linz Institute for Organic Solar Cells (LIOS), Physical Chemistry, Johannes Kepler University, Linz, Austria2Inistitute for Print and Media Technology, Chemnitz University of Technology, Chemnitz, Germany

In latest research, paper has become a very attractive material for building organic electronic devices that involve inexpensive materials and processes. Among the most attractive properties of paper are its biodegradability, biocompatibility, flexibility, versatility and low cost. But paper also presents high roughness and open porous structure which means that its surface shows low mechanical barrier properties for building organic thin layers from solutions.

This work presents some of the challenges and results obtained using paper as a substrate for organic solar cells. Here we used glossy paper coated with a thin Zn foil that acts as electrode but also as a mechanical barrier preventing the absorption of chemicals into the paper and improving the roughness. Organic solar cells were built using an inverted structure, with a metallic bottom electrode and a transparent conducting top electrode. Finally we explored transparent top contacts for their conductive versus transparency aspects.

Keywords: Paper – a new material for organic solar cells


282

Abstract:0430

Fabrication of Cu 2 ZnSnS 4 (CZTS) Nanofibers for Solar Cell Applications

Faruk Özel1,2, Burak Büyükbekar2,3, Hüseyin Sakalak2,3, Mahmut Kus2,4, Mustafa Selman Yavuz1,2 and Mustafa Ersöz2,4

1Department of Chemical Engineering, Selcuk University 42075, Konya, Turkey2Advanced Technology Research and Application Center, Selcuk University 42075, Konya, Turkey

3Department of Metallurgy and Materials Engineering, Selcuk University 42075 Konya, Turkey4Department of Chemistry, Selcuk University 42075, Konya, Turkey

Chalgenide based solar cells make possible a critical pathway to cost parity between photovoltaic (PV) and conventional energy sourges [1]. This indium-free quaternary chalcogenides (i.e. Cu 2 ZnSnS 4 (CZTS)) have driven much attention for their potential application in low cost solar cells due to their many advantages including an appropriate direct band gap (1.0-1.5 eV), high absorption coefficient, extremely low toxicity, high radiation stability, as well as relative abundance (indium free) of this elements [2].

In this work, we firstly achieved the synthesis of Cu 2 ZnSnS 4 nanofibers via electrospinning and metal deposition technique. These nanofibers are ranging from 150 nm to 700 nm depending on the concentration of the solution and solution material. The electrospinning process was carried out by using an aqueous solution containing copper chloride, zinc chloride, and tin (II) chloride. Homogeneous distribution characteristic of fibers has an average diameter of 200±10 nm. Figure 1 show SEM images of CZTS fibers.

Figure 1. SEM images of CZTS fibers.

References[1] T.K. Todorow, K.B. Reuter, D.B. Mitzi, Adv. Mater. 22, E156-E159 (2010)[2] J.-J. Wang, J.-S. Hu, Y.-G. Guo, L.-J. Wan, NPG Asia materials 4, 1038 (2012)


283

Abstract:0431

Solar Hydrogen Production based on Alloyed CdSeS Nanocrystals

Emre Aslan1, Osman Okan Birinci2,3, Imren Hatay Patir1, Mahmut Kus2,3, Mustafa Ersöz1,3

1Department of Chemistry, Selcuk University, Konya, Turkey, 2Department of Chemical Engineering, Selcuk University, Konya, Turkey

3 Advanced Technology Research & Application Center, Selcuk University Konya, Turkey.

Due to the running out of conventional fossil fuels, alternative energy sources have great attention [1]. Anomg these alternative sources, photocatalytic H2 production from water splitting by using semiconductors as photocatalysts has drawn considerable attention as a promising way of resolving global energy and environmental problems. Semiconductor nanocrystals, such as cadmium sulphide (CdS) and cadmium selenide (CdSe), have been used to generate hydrogen [2, 3]. But we have not reached any report on alloyed nanocrytals for solar photocatalytic hydrogen production.

In this study, we synthesized CdSeS with different composition and used them as photocatalyst for solar hydrogen production. X-ray diffraction (XRD), TEM, SEM, cyclic voltammetry (CV) and gas chromatography techniques are used for analysis and characterization. Catalytic activities of CdSeS nanocrystals have been compared with CdSe and CdS core nanocrystals. The results showed that CdSeS alloys show better activity than CdSe, CdS cores. Figure 1 shows the temporal evolution based on different nanocrytals.

Fig. 1. The evolution of hydrogen as a function of time (hour).

AcknowledgementsWe thank to TUBITAK (PN: 211T185) for financial support of this work.

References[1] Jing, D., Guo, L., Zhao, L., Zhang, X., Liu, H., Li, M., Shen, S., Liu, G., Hu, X., Zhang, X., Zhang, K., Ma, L., Guo, P., International Journal of Hydrogen Energy 35 ( 2010 ) 7087 – 7097[2] Zong, X., Yan, H., Wu, G., Ma, G., Wen, F., Wang, L., and Li, C., J. Am. Chem. Soc. 130 (2008) 7176–7177[3] Frame, F. A., Osterloh, F. E., J. Phys. Chem. C 114 (2010) 10628–10633

LIST OF PARTICIPANTS

List of Participants

286

Abdalaziz S A Aljabour

[email protected] Selçuk Üniversitesi Selçuk Üniversitesi Ileri Teknoloji Araştırma Ve Uygulama Merkezi Aleaddin Keykubat Kampüsü-konya

Konya Türkiye

Abdelfettah BARHDADI

[email protected] Mohammed V Agdal University

Ecole Normale Supérieure, semiconductors Physics And Solar Energy Research Team, Po Box 5118-takaddoum, Rabat

Rabat Morocco

Abdelkrim Kahoul [email protected] Faculty Of Engineering, University Sétif-1

Depart. Chemical Engineering, Faculty Of Engineering, University Sétif-1

Sétif Algeria

Abdenour Kabir [email protected] University 20 Août 1955-skikda

Pb 26 Route D'el-hadaiek Skikda Algeria

Adem Yar [email protected] Selçuk University Selçuk Üniversitesi Mühendislik Fak. Makina Müh. Bölümü

Konya Türkiye

Adenike Boyo [email protected] Lagos State University Lagos State University p.m.b.0001 Lasu Post Office badgry Expressway,ojo, Lagos,nigeria

Lagos Nigeria

Aderemi Babatunde Alabi

[email protected] University Of Ilorin, Ilorin, Nigeria

Department Of Physics university Of Ilorin p.m.b. 1515 ilorin

Ilorin Nigeria

Adewale Oriyomi Mudasir

[email protected] Zago Energy Ltd Lagos Lagos Nigeria

Adewale Sunday Mofolasayo

[email protected] University Of Agriculture, Abeokuta, Nigeria

Cocoa Research Institute Of Nigeria km 14 Ibadan-ijebu Ode Road, Idi Ayunre, P. M. B. 5244

Ibadan Nigeria

Adriana Pereira Ibaldo

[email protected] University Of Brasília Bss 283/57 - Icc Centro campus Darcy Ribeiro - Asa Norte brasília - Df postal Code: 70919-970

Brasília Brazil

Afolabi Micheal Ojo [email protected] Akinade Nigeria Limited 18 Adekunle Street Isolo Lagos Nigeria

Ahmet Emin Şentürk

[email protected] Gebze Instıtute Of Technology

Gebze Yüksek Teknoloji Enstitüsü P.k:41400 Malzeme Bilimi Ve Mühendisliği Binası Z-15 Gebze/kocaeli

Kocaeli Türkiye

Ahmet Nuri Ozcivan [email protected] Katip Celebi University Merkez Kampus, Cigli, Izmir Izmir Türkiye

Alan Jay Heeger [email protected] University Of California Santa Barbara

Department Of Physics university Of California

Santa Barbara

United States

Ali Cirpan [email protected] Middle East Technical University

Department Of Chemistry middle East Technical University universiteler Mahallesi dumlupinar Bulvari, No:1 06800 Ankara, Turkey

Ankara Türkiye

Amel Azazi [email protected] Faculty Of Sciences Of Monastir

Faculty Of Sciences Of Monastir Monastir Tunisia

Amel Benfredj-romdhane

[email protected] Tunis El Manar Département De Physique, Faculté Des Sciences De Tunis, Campus Universitaire El Manar

Tunis Tunisia

Andrea Radivo [email protected] University Of Trieste / Cnr Erta Di St'anna 128/1 Trieste Italy

Andrew Bruce Holmes

[email protected] University Of Melbourne 30 Flemington Road Melbourne Australia

Anita Fuchsbauer [email protected] Profactor Gmbh Im Stadtgut A2 Steyr-Gleink Austria

Anvar Zakhidov [email protected] The University Of Texas At Dallas

800 Campbell Road Richardson, Tx

United States

Name&Surname E-mail Affiliation Address City Country


287

Aren Yazmaciyan [email protected] Yildiz Technical University Yildiz Teknik Universitesi Davutpasa Kampusu, Fen Edebiyat Fakultesi, Davutpasa Cad. Esenler

Istanbul Türkiye

Arrigo Calzolari [email protected] Cnr-nano Institute Of Nanoscience

Via Campi 213a Modena Italy

Arved C Hübler [email protected] Tu Chemnitz Reichenhainer Str. 70 Chemnitz Germany

Atef Mohamed Amer

[email protected] Zagazig University Chemistry Depart., Faculty Of Science, Zagazig University, Zagazig, Egypt

Zagazig Egypt

Aušra Tomkeviciene [email protected] Kaunas University Of Technology

Radvilenu Rd. 19 Kaunas Lithuania

Aykut Aydin [email protected] Bilkent University 1506. Cad. No:12/1 cigdem Mah. / Cankaya

Ankara Türkiye

Ayse Turak [email protected] Mcmaster University 1280 Main St W Hamilton Canada

Ayşe Bedeloğlu [email protected] Bursa Technical University Bursa Technical University fiber And Polymer Engineering Department gaziakdemir Mah. Mudanya Cad. No4/10 16190 Bursa turkiye

Bursa Türkiye

Ayşenur Erdoğan [email protected] Selçuk Üniversitesi Selçuk Üniversitesi İleri Teknoloji Araştırma Ve Uygulama Merkezi Aleaddin Keykubat Kampüsü-konya

Konya Türkiye

Balazs Hetenyi [email protected] Bilkent University Department Of Physics bilkent University ankara 06800 Turkey

Ankara Türkiye

Bashiru Bolaji Balogun

[email protected] University Of Nigeria University Of Nigeria, Nsukka, enugu State, Nigeria

Nsukka Nigeria

Béchir Yangui [email protected] Faculté Des Sciences De Tunis

Faculté Des Sciences De Tunis campus Universitaire

Tunis Tunisia

Bedoui Denden Zouhour

[email protected] University Science Monastir/tunis

68 Isole El Agba Monastir Tunisia

Behnaz Bazoubandi [email protected] Ferdowsi University Of Mashhad

Iran,mashhad,hashemie 34.no 54 Mashhad Iran

Bello Okanlawon Hakeem

[email protected] Owo Gen Technical Company Ltd

30 Okota Rd Okota Nigeria

Benedict Molibeli Taele

[email protected] National Universtity Of Lesotho

Department Of Physics And Electronics, national University Of Lesotho, p.o. Roma 180, Lesotho

Maseru Lesotho

Bentahar Nourredine

[email protected] M'hamed Bougara University

Avenue De L'independance Boumerdes Algeria

Beri Nsoyani Mbenkum

[email protected] Centro Nacional De Microelectrónica (csic)

Instituto De Microelectronica De Barcelona centro Nacional De Microelectronica campus De La Universidad Autonoma De Barcelona S/n

Bellaterra (barcelona)

Spain

Bernd Ebenhoch [email protected] University of St Andrews North Haugh St Andrews United Kingdom

Bernhard Lamprecht

[email protected] Joanneum Research Forschungsgesellschaft Mbh

Franz Pichler Str. 30 Weiz Austria



288

Bettaibi Soufiene Soufiene

[email protected] Tunis Faculty Of Sciences Of Tunis, Department Of Physics, Thermal Radiation Unit, University Of Tunis El Manar

Tunis Tunisia

Birgit Paulik [email protected] University Linz Altenberger Straße 69 Linz Türkiye

Bouadila Salwa [email protected] The Research And Technology Center Of Energy

Hammam Lif, B.p. 95, 2050 Tunis, Tunisia

Ben Arous Tunisia

Boualem Abidri [email protected] University Université Djillali Liabès de Sidi Bel-abbes, Algeria

Sidi Bel-abbes

Algeria

Brima Alie Conteh [email protected] Ansevinternational 33 Lumley Street Freetown Sierra Leone

Bruno Jousselme [email protected] Cea Saclay 91191 Gif-sur-yvette France France

Bulembi Ndongala Pitshou

[email protected] Groupe De Recherche-action Pour Le Developpement Integral

23 Bis Kimbondo, C/mont-ngafula Kinshasa Congo, Democratic Republic of the

Bulent Basol [email protected] Encore Solar 6541 Via Del Oro, Suite B, San Jose, California

San Jose United States

Burak Gültekin [email protected] Ege University Ege Universtiy Solar Energy Institute 35100, Bornova Izmir

Izmir Türkiye

Burcu Altuntaş [email protected] Middle East Technical University

Üniversiteler Mah. Dumlupınar Bulv. No:1 Çankaya

Ankara Türkiye

Bünyamin Ümsür [email protected]

Helmholtz Zentrum Berlin Albert-einstein-str. 15 Berlin Germany

Cahyorini Kusumawardani

[email protected] Yogyakarta State University Karangmalang, Depok, Sleman yogyakarta

Yogyakarta Indonesia

Can Erkey [email protected] Türkiye

Canan Baslak [email protected] Selcuk University Selcuk University Sicence Faculty Chemistry Department

Konya Türkiye

Carlo Andrea Rozzi [email protected] Cnr Via Campi 213a Modena Italy

Cesar Kapseu [email protected] University Of Ngaoundere P O Box 455 Ngaoundere Cameroon

Ceylan Zafer [email protected] Ege University Ege University, Solar Energy Institute Bornova

Izmir Türkiye

Chadlia Manaa [email protected] Tunis El Manar Faculté Des Sciences De Tunis El Manar

Tunis Tunisia

Chaker Zaghdoudi [email protected] Institut National Des Sciences Appliquées Et De Technologie (insat)

Centre Urbain Nord Bp N° 676 Tunis Tunisia

Changduk Yang [email protected] Interdisciplinary School Of Green Energy

Unist Gil 50, Eonyang Eup, Ulju Gun

Ulsan South Korea

Chifundo Martin Tenthani

[email protected] University Of Malawi Private Bag 303 chichiri, Blantyre 3

Blantyre Malawi

Chihi Adel [email protected] Centre Des Recherches Et Des Technologies De L'energie Technopole Borj Cedria

Centre Des Recherches Et Des Technologies De L'energie Technopole Borj Cedria b.p N°95 2050 - Hammam Lif - Tunisie

Borj Cedria Tunisia

Ching W Tang [email protected] University Of Rochester Gavett Hall, University Of Rochester PO Box 270166

Rochester United States

Christina Enengl [email protected] Jku Altenbergerstraße 69 4040 Linz Linz Austria



289

Cigdem Yumusak [email protected] Yildiz Technical University Ytu Davutpasa Kampusu fen-edebiyat Fakultesi, E-blok fizik Bolumu esenler

Istanbul Türkiye

Dalia El-sayed Abozied

[email protected] Desert Research Center 2148 Merag City, Maadi Cairo Egypt

Dalius Gudeika [email protected] Kaunas University Of Technology

Radvilėnų Pl. 19 Kaunas Lithuania

Daniel Ayuk Mbi Egbe

[email protected] Johannes Kepler University Linz

Altenbergerstr. 69 Linz Austria

Daniel Moses [email protected] University Of California Center For Polymers And Organic Solids

Santa Barbara, California

United States

Daniel Nocera [email protected] Harvard University 12 Oxford Street Cambridge United States

David Cahen [email protected] Weizmann Institute Of Science

Perlman 620 Rehovot Israel

David Faiman [email protected] Ben-gurion University Sde Boker Campus Midreshet Ben-gurion

Israel

David Ginley [email protected] National Renewable Energy Laboratory

15013 Denver West Parkway Golden, Co United States

David Leslie Officer [email protected] University Of Wollongong University Of Wollongong innovation Campus northfields Avenue

Wollongong Australia

Derya Eren [email protected] Türkiye

Desta Antenehe Gedefaw

[email protected] Chalmers University Of Technology

Chalmers University Of Technology, polymer Technology, kemivagen 10

Gothenburg Sweden

Diana Susarova [email protected] Ras Academician Semenov Avenue 1, Chernogolovka, Moscow Region, Russia

Chernogolovka Russia

Diego Colombara [email protected] Université Du Luxembourg 41, Rue Du Brill Belvaux Luxembourg

Dilek Dogutan Kiper [email protected] Harvard University 12 Oxford Street Cambridge United States

Divine Osamiromwen Ojuh

[email protected] Benson Idahosa University G. R. A. Benin City Nigeria

Dmitriy Novikov [email protected] Ras Academician Semenov Avenue 1, Chernogolovka, Moscow Region, Russian Federation

Chernogolovka Russia

Dogan Mansuroglu [email protected] Middle East Technical University

Middle East Technical University Physics Department Room 129

Ankara Türkiye

Doğukan Hazar Apaydın

[email protected] Johannes Kepler University Altenberger Street, 69 Linz Türkiye

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290


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Elham Sadullah Altalibi

[email protected] University Of Mosul University Of Mosul education College / Chemistry Dept. mosul iraq

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[email protected] Mosul University College Of Education Mosul Iraq

Emin Istif [email protected] Yıldız Technical University Esenşehir Mahallesi, Medeniyet Sokak, Birlik Sitesi, A Blok Daire 3

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Diyarbakir Türkiye

Emmanuel Dami Kajewole

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Estavromenos Heraklion Greece

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Eric Daniel Glowacki [email protected] Johannes Kepler University Altenbergerstrasse 69 Linz Austria

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Ehitajate Tee 5 Tallinn Estonia (Eesti)

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Simorgh Complex- Jourmand St- Orumian St. Ajudanie St. Tehran - Iran

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33 El-behooth Street, Dooki, Giza, Egypt

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Hamadi Khemakhem

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Hande Emine Çiftpınar

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[email protected] Ain Shams University 390 Zahiaa Nasr City Cairo Egypt

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P.o.box 2807 Osu Accra Ghana

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Arıteks Boyacılık Hacı Şeramet 4. Sok. Yulaflı Çorlu

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Ifor Samuel [email protected] University Of St Andrews School Of Physics And Astronomy north Haugh

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Imadalou Mourad [email protected] Ecole Normale Supérieure De Kouba Alger-algérie

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Imen Jmal Kammoun

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Fysikvej 307 Kgs. Lyngby Denmark

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Fsdm, B.p.1796, Fes-atlas Fes Morocco

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Jean Roncali [email protected] Cnrs University Of Angers 2 Bd Lavoisier Angers France

Jenny Nelson [email protected] Türkiye

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John Njagi Nguu [email protected] Daystar University P.o.box 44400 nairobi Nairobi Kenya

John Perlin [email protected] University Of California, Santa Barbara

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Santa Barbara

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Industriestr. 6 Stuttgart Germany

Joseph Giorgio [email protected] University Of Wollongong Aiim Building innovation Campus university Of Wollongong

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Juergen Scheffran [email protected] GermanyJuozas Vidas Grazulevic

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Donelaicio 73 Kaunas Türkiye

Justus Simiyu [email protected] University Of Nairobi Department Of Physics, P.o. Box 3019 - 00100 Narob

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Kadir Demirak [email protected] Ege University Ege University Solar Energy Institute

Izmir Türkiye

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Bp37 Le Belvedere 1002 Tunis Tunis Tunisia

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Via Bonomea 265 Trieste Italy

Kasim Ocakoglu [email protected] Mersin University Advanced Technology Research & Application Center, Mersin University, Ciftlikkoy Campus

Mersin Türkiye

Kerstin Oppelt [email protected] Johannes Kepler University Linz

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Kessel Pombe Joseph

[email protected] Higher Institut Of Sahel Po.box: 46 Maroua Cameroon

Kessel Pombe Joseph

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Unité De Recherche De Matériaux Et Energies Renouvelables (urmer), Département De Physique, Université De Tlemcen, B.p119 (13000).

Tlemcen Algeria

Khurram Saleem Joya

[email protected] Leiden University Einsteinweg 55 Leiden Netherlands

Klemens Grabmayer


Altenberger Straße 69 Linz Austria

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Koushik Majhi [email protected] Institute For Nanotechnology & Advanced Materials

Dr. Koushik Majhi institute For Nanotechnology & Advanced Materials, bar Ilan University, ramat Gan, 52900 israel

Ramat Gan Israel

Kyucheol Lee [email protected] Unist Unist-gil 50, Ulsan 689-798, Republic Of Korea.

Ulsan South Korea

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[email protected] Berlin Technical University Technische Universität Berlin institut Für Chemie ak Fischer tk-gebäude sek. Tk01 raum Tk128 straße Des 17. Juni 135

Berlin Germany

Lidong Wang [email protected] Ruhr-university Bochum Universitätsstr. 150; Nc 4/073 Bochum Germany

Lucia Nicoleta Leonat

[email protected] Jku Altenbergerstraße 69 Linz Austria

Mahmut Kus [email protected] Selcuk University Selcuk University, Department Of Chemical Engineering Kampus

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Iran-mashhad-sanabad 47-eram 1

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Marek Havlicek [email protected] Linz Institute For Organic Solar Cells

Altenberger Str. 69 Linz Austria

Maria Antonietta Loi

[email protected] University Of Groningen Nijenborgh 4 Groningen Netherlands

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Mark Speirs [email protected] University Of Groningen Nijenborgh 4 Groningen Netherlands

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[email protected] University Of Silesia Institute Of Chemistry 9 Szkolna Str.

Katowice Poland

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1-2-1 Sengen Tsukuba, Ibaraki

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23 Bis Kimbondo, C/ Mont-ngafula

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Michael Walter Tausch

[email protected] Bergische Universität Wuppertal

Gaußstr. 20 l13-01 Wuppertal Germany

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Mohamed Abd Alobeady

[email protected] Mosul Iraq Mosul Iraq

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Setif Algeria

Mohamed Keli [email protected] Mohammadia School Of Engineers

Mohammadia School Of Engineers, Agdal, Rabat.

Rabat Morocco

Mohamed Remram [email protected] Constantine1 Route Ain El Bey Constantine Constantine Algeria

Mohammed Jamal Dini

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Box 4388 Adum Kumasi Kumasi Ghana

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Radvilenu Pl. 19 Kaunas Lithuania

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National Engineering School Of Sfax box Mail N° 1173

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[email protected] National University Of Sciences & Technology

Nust sector H-12 islamabad, Pakistan.

Islamabad Pakistan

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Islamabad Pakistan

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Izmir Türkiye

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Karabuk Türkiye

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Altenbergerstr. 69 Linz Austria

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Moanstir Tunisia


297


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[email protected] Faculty Of Sciences Of Sfax Faculty Of Sciences Of Sfax, B.p. 1171

Sfax Tunisia

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Istanbul Türkiye

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[email protected] Linz Institute For Organic Solar Cells (lios)

Altenbergerstrasse 69 Linz Austria

Nkiruka Francisca Oparaku

[email protected] University Of Nigeria, Nsukka

911 Murtalla Mohammed Str, Unn Nsukka Nigeria

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Konya Türkiye

Oleg Dimitriiev [email protected] Institute Of Semiconductor Physics Nas Of Ukraine

Pr. Nauki 41 Kyiv Ukraine

Olena Kozlova [email protected] Johannes Kepler Universitty Altenbergstrasse 69 Linz Austria

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Olgu Demircioğlu [email protected] Türkiye

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Universiteler Mah. Dumpupinar Bulv. No.1 Çankaya

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Onana Onana Pascal Belon

[email protected] Agropav 2705yde-messa Yaounde Cameroon

Onur Yaşgüçlükal [email protected] Trakya University Dogruyol Sok. Şafak Apt. No:16/7 Yeşilköy Bakırköy

Istanbul Türkiye

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Nsukka Nigeria

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Kastamonu Türkiye

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Germany


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[email protected] Chulalongkorn University Chula Unisearch 254 Chulalongkorn University, Pyathai Road, Pathumwan District

Bangkok Thailand

Patrick Denk [email protected] JKU Altenbergerstraße 69, 4040 Linz,

Linz Austria

Patrice Ngan Kee Ngan

[email protected] Solartehc Infos.sa Rue Des Ecoles Akwa Douala Cameroon

Peter Wuerfel [email protected] Karlsruhe Institute Of Technology Kit

Private Address: oppelner Str. !5 D Karlsruhe Germany

Petro Semenovich Smertenko

[email protected] V.lashkaryov Institute Of Semiconductor Physics Of National Academy Of Sciences Of Ukraine

45, Prospekt Nauki Kyiv Ukraine

Philipp Stadler [email protected] Johannes Kepler University Linz


Prosper Ahmed Amuquandoh

[email protected] Energy Commission Of Ghana

Ministries Post Office, airport Residential Area, behind Alliance Franciase

Accra Ghana

Ramunas Lygaitis [email protected] Kaunas University Of Technology

Radvilenu 19 Kaunas Lithuania

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Reinhold Priewasser

[email protected] Johannes Kepler University Linz/austria


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Po Box 513 Eindhoven Netherlands

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Ridha Chargui Chargui

[email protected] Faculty Of Sc. Of Tunisia 3 Rue 6753 Tunis. Tunisia Tunis Tunisia

Robinson Juma Musembi

[email protected] University Of Nairobi P.o. Box 30197 Nairobi Kenya

Rolant Eba Medjo [email protected] University Of Douala Faculty Of Science, University Of Douala, Cameroon

Douala Cameroon

Roman Adinberg [email protected] Weizmann Institute Of Science

234 Herzl St. Rehovot Israel

Sabry A Abdel-mottaleb

[email protected] Ain Shams University Abbassia, Cairo Cairo Egypt

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El Jadida Morocco

Salih Okur [email protected] Izmir Katip Çelebi University Balatçık Campus, Çiğli Izmir Türkiye

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Samed CETİNKAYA [email protected] Mustafa Kemal University Mustafa Kemal University, Tayfur Sokmen Campus, Art And Science Faculty. Departmant Of Physicstayfur Sokmen Campus, Alahan, Antakya,31034, Hatay

HATAY Türkiye

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Faculty Of Sciences And Nature Sciences And Life tebessa University constantine Road, 12002 Tebessa Algeria

Tebessa Algeria


299


Samir Romdhane [email protected] Tunis El Manar Département De Physique, Faculté Des Sciences De Tunis, Campus Universitaire

Tunis Tunisia

Sana Ben Amor [email protected] Technopole Borj Cedria Borj Cedria Hammam Lif Tunisia Hammam Lif

Tunisia

Sandra Enengl [email protected] Jku Altenbergerstraße 69 4040 Linz Linz Austria

Sara Gusner [email protected] Jku University Of Linz Altenbergerstraße 69 Linz Austria

Selcan Ates [email protected] Izmir Institute Of Technology

Iyte gulbahce Koyu, Urla Izmir Türkiye

Selma Mayda [email protected] Izmir Institute Of Technology

Department Of Physics, Gulbahce, Urla, Izmir

Izmir Türkiye

Serafettin Demic [email protected] Izmir Katip Celebi Üniversity Ataturk Organize Sanayi Bolgesi a.o.s.b. Mahallesi Havaalani Sosesi no:33/2 cigli

Izmir Türkiye

Serap Günes [email protected] Yildiz Technical University Yildiz Technical University, Fac. Of Arts And Science, Physics Dept. Davutpasa Campus, Esenler

Istanbul Türkiye

Sermet Koyuncu [email protected] Canakkale Onsekiz Mart University

Canakkale Onsekiz Mart University can Vocational College can

Canakkale Türkiye

Serpil Edebali [email protected] Selcuk University S.u. Faculty Of Engineering Dept. Of Chemical Engineering Campus

Konya Türkiye

Serpil Tekoglu [email protected] Karlsruhe Institute Of Technology

Engesserstrasse 13 building 30.34 germany

Karlsruhe Germany

Seyfettin Gürel [email protected] Türkiye

Shaimaa Ali Mohamed Ahmed

[email protected] Zewail City Of Science And Technology

Sheikh Zayed District 6th Of October City 12588 giza, Egypt

Cairo Egypt

Shashi Sharma [email protected] University Of Rajasthan 1282, First Floor, Vinay Path, Barkat Nagar, Tonk Phatak (jaipur)

Jaipur India

Sherine Obare [email protected] Western Michigan University

2645 Arrowwood Lane Kalamazoo United States

Shozo Yanagida [email protected] Osaka University 8-1, Mihoga-oka, Ibaraki Japan

Siddik Icli [email protected] Ege Univ. Lojmanlar Kampusu, Ege Univ., Bornova

Izmir Türkiye

Sihem Jaziri [email protected] Faculté Des Sciences De Bizerte

Jarzouna Bizerte Tunisia bizerte Tunisia

Sinem Tuncel [email protected] Gebze Institute Of Technology

Gebze Institute Of Technology faculty Of Science Department Of Chemistry P.o. Box 141 Gebze

Kocaeli Türkiye

Skouri Safa [email protected] The Research And Technology Center Of Energy

Hammam Lif, Tunisia Tunis Tunisia

Sonay Karaman [email protected] Türkiye

Sonia Ben Slama [email protected] Technopole Borj Cedria B.p 95 Hamam-lif Borj-cedria Türkiye

Sorina Iftimie [email protected] University Of Bucharest 405 Atomistilor Magurele Romania

Stefan Antohe [email protected] University Of Bucharest 405, Atomistilor Street Magurele-ilfov

Romania

Stefanie Schlager [email protected] Johannes Kepler University Linz


Stergios Logothetidis

[email protected] Aristotle University Of Thessaloniki

Aristotle University Campus Thessaloniki Greece


300


Steven J Konezny [email protected] Yale University P.o. Box 27394 West Haven, Ct

United States

Sule Erten Ela [email protected] Ege University Ege Unıversıty Solar Energy Institute 35100 Bornova Izmir

35100 Türkiye

Sumeyra Buyukcelebi

[email protected] Selcuk University Selcuk University, Advanced Technology Research And Application Center Konya Turkey

Konya Türkiye

Sureyya Aydin Yuksel

[email protected] Yildiz Technical Uni. Davutpasa Campus Istanbul Türkiye

Tanay Sıdkı Uyar [email protected] Marmara University Marmara University Faculty Of Engineering Department Of Echanical Engineering Goztepe Campus Kadıköy

Istanbul Türkiye

Tareq Abu Hamed [email protected] Arava Institute Kibbutz Ketura Eilot Israel

Teketel Yohannes Anshebo

[email protected] Addis Ababa University Chemistry Department/materials Science Program p. O. Box 1176 addis Ababa University, addis Ababa, Ethiopia

Addis Ababa

Ethiopia

Thomas Zapf [email protected] University Of Natural Resources And Life Sciences, Vienna

Muthgasse 11/2 1190 Vienna austria

Vienna Austria

Tobias Grewe [email protected] Max-planck-institute Für Kohlenforschung

Kaiser-wilhelm-platz 1 Mülheim Germany

Tomas Torres [email protected] Autonoma University Of Madrid

C/ Francisco Tomas Y Valiente, 7 cantoblanco

Madrid Spain

Tracey Clarke [email protected] University Of Wollongong Aiim Facility, Building 231, Innovation Campus, Squires Way

North Wollongong

Australia

Tsukasa Yoshida [email protected] Yamagata University Jonan 4-3-16 Yonezawa Japan

Tsutomu Miyasaka [email protected] Toin University Of Yokohama 1614 Kurogane-cho, Aoba Yokohama Japan

Tuğbahan Yılmaz Alıç

[email protected] Selçuk Üniversitesi Selçuk Üniversitesi İleri Teknoloji Araştırma Ve Uygulama Merkezi Aleaddin Keykubat Kampüsü-konya

Konya Türkiye

Ubachukwu Stanley [email protected] Media Right Agenda No 5 Gonder Close Zone 1 Abuja Abuja Nigeria

Ufuk Abacı [email protected] Kocaeli University Türkiye

Ufuoma Okpugwo [email protected] Youth Federation For World Peace

Bujumbura Street,wuse 2 Abuja Nigeria

Ullrich Scherf [email protected] Bergische Universitaet Wuppertal

Macromolecular Chemistry Group Gauss-Str. 20

Wuppertal Germany

Ulrich Scherf [email protected] Türkiye

Umut Dogar Cakmak

[email protected] Johannes Kepler University Altenbergerstr. 69 Linz Austria

Valeriy Kobryanskiy [email protected] P.n.lebedev Physical Institute, Ras, Russia

Leninsky Pr. 53 Moscow Russia

Vasyl Chyhin [email protected] Lviv Academy Puluya Str. 13, 61 Fl. Lviv Ukraine

Victor Busa- Osowo Bisong

[email protected] Cowry Asset Management Ltd

Plot 1319 karimu Kotun Street victoria Island lagos

Lagos Nigeria

Victor Klimov [email protected] Los Alamos National Laboratory

Ms-j567 Los Alamos United States

Viktorija Mimaite [email protected] Kaunas University Of Technology

Radvilenu Pl. 19 Kaunas Lithuania


301


Vittoria Roiati [email protected] Iit-italian Institute Of Technology

Via Barsanti Arnesano (lecce)

Italy

Vlad Andrei Antohe [email protected] Université catholique De Louvain

Place Croix Du Sud 1, Bâtiment Boltzmann A(+1), A.121, Bte.: L7.04.01,

Louvain-la-neuve

Belgium

Vladimir Astachov [email protected] University Of Nottingham University Park Nottingham United Kingdom

Walter Kohn [email protected] Uc Santa Barbara 236 La Vista Grande Santa Barbara

United States

Wolfgang Heiss [email protected] Johannes Kepler University Altenbergerstraße 69 Linz Austria

Wolfgang Tress [email protected] Linköping University - Linköping Sweden

Xiao-feng Wang [email protected] Yamagata University Jonan 4-3-16 Yonezawa Japan

Yacoub Idriss Halawlaw

[email protected] Türkiye

Yasemin Topal [email protected] Selcuk University Selçuk Üniversitesi Alaaddin Keykubat Kampüsü Teknokent Binasi konya / Selçuklu

Konya Türkiye

Yasin Kanbur [email protected] Karabuk University Karabük Üniversitesi mühendislik Fakültesi metalurji Ve Malzeme Mühendisligi Bölümü

Karabük Türkiye

Yongfang Li [email protected] Chinese Academy Of Sciences

No.2, The North First Street Of Zhongguancun

Beijing China

Yulia Ievskaya [email protected] University Of Cambridge Trinity Hall Wychfiled storey's Way CAMBRIDGE United Kingdom

Zafra Lerman [email protected] Malta Conferences Foundation

1911 Grant St. Evanston United States

Zaïbi Mohamed-ali [email protected] Esstt 5 Avenue Taha Hussein Tunis Tunisia

Zeynep Bozkurt [email protected] Johannes Kepler University Altenbergerstrasse 69 Linz Austria

Zeynepcan Akar [email protected] St. Lawrence University Yanarsu Sok. Pirelli Sitesi B Blok no:15 Da:16 Etiler istanbul, Turkey

Istanbul Türkiye

Zheng Tang [email protected] Linköping University Linköping University Linköping Sweden

Zied Ben Hamed [email protected] Faculté Des Sciences 13 Street Kaadine,babsoika Tunis Tunisia Tunisia

Zinat Aliyu [email protected] Mic-de-frank International Limited

Shop 14 Dilimu Market Jos Nigeria Jos Nigeria

Zoltán Szabó [email protected] HAS Research Centre For Natural Sciences

Konkoly Thege M. str. 29-33. Budapest Hungary

Zoungrana Martial [email protected] University Of Ouagadougou Département De Pyhsique/ Ufr-sea université De Ouagadougou

Ouagadougou 03

Burkina Faso

Zuhoor Fathi Dawood

[email protected] University Of Mosul Chemistry Department, College Of Education, University Of Mosul

Mosul Iraq

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SPONSORS

The organisation of the Solar Energy for World Peace would not possible without the generous support of our sponsors and supporting organisations. Therefore, our particular thanks go to the following organisations and companies:

Austrian Science Foundation

World PeaceSolar Energy for

August 17-19, 2013Istanbul / Turkey

w w w . s o l a r 4 p e a c e . o r g

Local OrganisationHalaskargazi Cad. Tavukçu Fethi Sok. Köşe Palas Apt. No:28/3 Osmanbey - Şişli - İstanbul / TURKEYTel:+90 (212) 296 66 70 pbx Fax:+90 (212) 296 66 [email protected] www.brosgroup.net

Conference Secretary: Sara GusnerTel: +43-732-2468 1770 / Fax: +43-732-2468 8770E-mail: [email protected]

Conference Chairman:O.Univ.Prof.Mag.Dr. DDr.h.c. Niyazi Serdar Sariciftci, Ordinarius (Chair) Professor for Physical ChemistryJohannes Kepler University of Linz, Austria E-mail: [email protected]

Solar Energy for World Peace

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