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Nanocrystal Solar Cell NanoPaint™ for Solar Car

Sarah Swisher, Huai-Yuan Michael Tseng, Kyle Braam

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OutlineMotivation: the Global Energy CrisisReview current PV technologyInorganic Nanocrystal solar cell

BenefitsResearch resultsFuture potential

NanoPaint™ for charging electric vehicles

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Global Energy IssuesLimited supply of fossil fuelsEnergy securityPolitical instabilityEconomicsEnvironmental: CO2, global warming,

pollution…. all this combined with an increasing

population!

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Hydroelectric

Tide

Wind

Geothermal

Solar

0.1

1.5

15.0

150.

0

1,50

0.0

15,0

00.0

150,

000.

0

1

2

4

12 120,000

Global Renewable Energy Resources (TW)

Solar energy that strikes the earth’s surface per hour: 4.3 x 1020 JWorld energy consumption in one year: 4.1 x 1020 J

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Solar Cell Operation

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Figures of MeritOpen circuit voltage, VOC

Short circuit current, ISC

Energy conversion efficiency, ηThermodynamic efficiency limitQuantum efficiency, EQE and IQEMaximum power point, PMAX

Fill Factor, FF

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PV Progress in Research

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TECHNOLOGY DETAILSNanocrystal Solar Cell

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What are nanocrystals ?

2 ~ 10 nm10 ~ 50 atoms

Eg

1S(e)

1P(e)

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Why Nanocrystals Solar Cell?

Low-Cost

Large area

Flexible substrate

Solution process

Printing

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Assumption in Shockley-Queisser

Approach which circumvents assumption

ExamplesTheoretical efficiency

One photon = one electron-hole pair

Multiple absorption path solar cells

Impact ionization 42%

One quasi-Fermi level separation

Multiple energy level solar cells

Intermediate bandQuantum well solar cells 87%

Constant temperature = cell temperature = carrier temperature

Multiple temperature solar cells.

Hot carrier solar cells 66%

Why Nanocrystals Solar Cell ?

30%

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P3HT/CdSe nanorods Hybrid

Wendy U. Huynh, Janke J. Dittmer, A. Paul Alivisatos. Science 295, 2425 (2002)

poly-3(hexylthiophene)

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CdTe/CdSe nanorods

Gur I, Fromer N. A, Geier M. L, Alivisatos A. P. Science 2005; 310: 462-465.

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CIGS Nanoparticle Precursor

Inkjet printable

Roll-to-Roll

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CIGS Nanoparticle Precursor

Vijay K. Kapur*, Ashish Bansal, Phucan Le, Omar I. Asensio. Thin Solid Films 431 –432 (2003) 53–57

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CIGS Nanoparticle Precursor

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ComparisonP3HT/CdSe NR CdTe/CdSe NR CIGS NP

Isc (mA/cm2) 5.7 13.2 37.3 37.9Voc (V) 0.7 0.45 0.52 0.44

Fill Factor 0.4 0.49 0.71 0.61Efficiency (%) 1.7 2.9 13.6 10.1

Substrate ITO/Glass ITO/Glass Glass Mo foil

Printability Poor Poor Good (inkjet/screen printing)

Temperature Low Medium MediumReliability Non-stable Air stable Air Stable

Environmental Unfriendly Unfriendly Friendly

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APPLICATIONNanoPaint™ for Solar Car

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Solar Car

North American Solar ChallengeCars drive at speed limit: 65 mphWinning time: 51 hours, 41 minutes, and 53

seconds

University of Michigan Solar car University of California Berkeley Solar Car

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Solar Electric Vehicles Astrolab solar concept car from Venturi

Electric

Solar cells: 21% efficient1 Day of sun=11 miles

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Solar Electric Vehicles 1992 Mazada 929 Luxury Sedan

Solar cells run fan to cool car and can recharge the car’s battery

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Solar Electric Vehicles2010 Prius

Solar roof package: $3,600Powers fan to cool the interior by 20 degreesOnly available for certain models

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Solar Electric VehiclesSolar Electric Vehicle photovoltaic module

16% efficient, 215 Watts1 Day of sun =range of 5 to 8 miles $4,000

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Solar Electric VehiclesDisadvantages of models

Cost: single crystallineWeightStructure

Solution:Solar Cells based on CIGS nanoparticles“Solar Cell NanoPaint™”

Source: http://www.cartuningcentral.com/how-to-paint-a-car

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Solar Cell NanoPaint™

Our painting process of the CIGS nanoparticle on the solar car was covered by

National Geographic Channel

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Solar Cell NanoPaint™Market Comparison

Solar Electric Vehicles

Solar CellNanoPaint™

Optimized Solar Cell NanoPaint™

Material Single Crystalline CIGS Nanoparticle CIGS NanoparticleEfficiency 16% 10% 19%

Weight Moderate low LowArea 1.507 m2 7.67 m2 7.67 m2

Lifetime Long-20 years long-20 years Long-20 yearsPower Output 215 Watts 767 Watts 1457 WattsDriving range 5-8 Miles 18-28 Miles 34-51 MilesEnvironmental

Hazardmoderate Low Low

Cost $4,000 low-$2000 Lower-$1500

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Solar Cell NanoPaint™ Market Analysis

Increasing hybrid electric vehicle sales will drive demand for Solar Cell NanoPaint™

Market Analysis

Market Hybrid Electric vehicles

Total number of Vehicles in the US 247 Million

Number of Hybrid Vehicles currently available in US

1-2 Million

Revenue Assuming 1% Conversion of Available Hybrids

40 Million Dollars

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Hybrid Sales In the US

Source: http://www.cartuningcentral.com/how-to-paint-a-car

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ConclusionPhotovoltaicsNanoparticle Systems

P3HT/CdSeCdTe/CdSeCIGS nanoparticle

CIGS NanoPaint™ Solar CellSolar hybrid electric vehicle