Synthesis of zn se nanocrystals (1)
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Synthesis Of ZnSe Nanocrystals, Study of its properties and applications. By : JITESH KUMAR(BE/15007/12) ATISH SINHA(BE/15009/12) GAURAV RAJ ANAND(BE/15067/12) Under the guidance of Prof. S.K CHAUBEY 1 [email protected]
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Transcript of Synthesis of zn se nanocrystals (1)
Synthesis Of ZnSe Nanocrystals, Study of its properties and applications.
By :JITESH KUMAR(BE/15007/12)ATISH SINHA(BE/15009/12)
GAURAV RAJ ANAND(BE/15067/12)Under the guidance of Prof. S.K CHAUBEY
CONTENTS
• Abstract• Introduction• Objective• Methodology• Work Done• Results• Applications• References
ABSTRACT
Highly crystalline, well-dispersed ZnSe nanocrystal with a relatively narrow particle size distribution was successfully synthesized by using solvo-thermal mechanism using ZnCl2, Se powder , hydrazine hydrate and ethylene glycol. The samples were characterized by means of X-ray diffraction (XRD), and Fourier transform infrared (FT-IR). All the desired properties of nanocrystals prepared here imply the possibility of high quality ZnSe nanocrystals developed under the appropriate reaction conditions. These properties were further applied in various applications like Cancer Detection and improving existing solar cells.
Introduction
Nanocrystals• A nanocrystal is a crystalline particle with at least one
dimension measuring less than 1000 nanometers (nm), where 1 nm is defined as 1 thousand-millionth of a meter (10-9 m).
• The size of nanocrystals distinguishes them from larger crystals. For example, silicon nanocrystals can provide efficient light emission while bulk silicon does not and may be used for memory components.
• Semiconductor nanocrystals having dimensions smaller than 10nm are also described as quantum dots.
Application of Nanocrystals:
• Illumination • Flat panel display • Refining of Crude Oil into Diesel • Optical and Infrared Lasers • Removal of pollutants and toxins • Solar panels • Drug Manufacture • Protein Analysis • Bio-tags for gene identification• Cancer Detection
Zinc Selenide:• Zinc selenide (ZnSe) is a light-yellow, solid compound comprising zinc (Zn)
and selenium(Se).• It is an intrinsic semiconductor with a band gap of about 2.70 eV at 25 °C
(77 °F). • ZnSe rarely occurs in nature, and is found in the mineral that was named
after Hans Stille called "stilleite“.
Properties of ZnSe:• ZnSe can be made in both hexagonal (wurtzite) and cubic (zincblende)
crystal structure.• It is a wide-bandgap semiconductor of the II-IV semiconductor
group (since zinc and selenium belong to the 12th and 16th groups of the periodic table, respectively).
• The material can be doped n-type doping with, for instance, halogen elements. P-type doping is more difficult, but can be achieved by introducing gallium .
Applications of Zinc Selenide:• ZnSe is used to form II-VI light-emitting
diodes and diode lasers. It emits blue light.• ZnSe doped with magnesium (ZnSe:Mg) has been used
as an infrared laser gain medium emitting at about 2.4 µm.
• In daily life, it can be found as the entrance optic in the new range of "in-ear" clinical thermometers, seen as a small yellow window
• ZnSe activated with tellurium is a scintillator with emission peak at 640 nm, suitable for matching with photodiodes. It is used in x-ray and gamma ray detectors.
OBJECTIVE
• Synthesis of Zinc Selenide Nanocrystals • Study of its optical and electrical properties • Preparation of Doped ZnSe • Application in Cancer Detection • Application in Photovoltaic Cells
Methodology
• The methodology used in preparation of ZnSe nanocrystals by us is called solvo thermal synthesis method.
• In this case, we use water as a solvent, because of which it is called hydrothermal synthesis.
• Solvothermal synthesis is a method for preparing a variety of materials such as metals, semiconductors, ceramics, and polymers.
• The process can be used to prepare many geometries including thin films, bulk powders, single crystals, and nanocrystals.
• The method can be used to prepare thermodynamically stable and metastable states including novel materials that cannot be easily formed from other synthetic routes.
• Over the last decade, a majority (~80%) of the literature concerning solvothermal synthesis has focused on nanocrystals.
• A magnetic stirrer was used for this process, which was set at different RPMs for a good number of hours for mixing and drying.
• A microwave was used for further drying.
WORK DONE
Chemicals Required:• 1. Selenium Powder - 2gms • 2. Zinc Chloride - 4gms • 3. Ethylene Glycol - 54mL • 4. Hydrazine Hydrate – 18.5mL • 5. Distilled Water – 126mL • 6. Mg – 0.4gms
• In the typical synthesis of ZnSe, highly pure ZnCl2 powder (99.9%) and elemental Selenium (99.999%) was used without further purification. Ethylene glycol and Hydrazine hydrate were also used.
• In this synthesis process, ZnCl2 (4.0 g) and elemental selenium (2.0 g) was taken with deionized water, ethylene glycol and hydrazine hydrate in the volume ratio of 7:3:1 respectively in a 200ml capacity conical flask.
• The solution is then put on a magnetic stirrer for a good number of hours at 60 degree celcius and then filtered out.
• The filtered sample is then dried in microwave for apprx. 10 mins at 120 degree celcius.
EQUATIONS: 1. ZnCl2 + Se + X ZnSe X = C2H6O6 + N2H4 + H2O 2.ZnCl2 + Se + X + Mg ZnSe:Mg
ZnSe IV
Operations: Smooth 0.150 | Background 1.000,1.000 | ImportFile: SAIFXR160217C-04 (ZnSe-IV).raw - Step: 0.020 ° - Step time: 29.1 s - WL1: 1.5406 - kA2 Ratio: 0.5 - Generator kV: 35 kV - Generator mA: 35 mA - Type: 2Th/Th locked
Lin
(Cou
nts)
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2-Theta - Scale
3 10 20 30 40 50 60 70 80
ZnSe IV
Operations: Smooth 0.150 | Background 1.000,1.000 | Import8)
7)6)5)4)3)2)1)File: SAIFXR160217C-04 (ZnSe-IV).raw - Step: 0.020 ° - Step time: 29.1 s - WL1: 1. Obs. Max: 47.747 ° - FWHM: 0.439 ° - Raw Area: 5.503 Cps x deg.
Obs. Max: 43.699 ° - FWHM: 0.370 ° - Raw Area: 9.752 Cps x deg. Obs. Max: 32.924 ° - FWHM: 0.209 ° - Raw Area: 10.32 Cps x deg. Obs. Max: 31.768 ° - FWHM: 0.237 ° - Raw Area: 23.03 Cps x deg. Obs. Max: 29.726 ° - FWHM: 0.316 ° - Raw Area: 28.02 Cps x deg. Obs. Max: 23.535 ° - FWHM: 0.345 ° - Raw Area: 11.14 Cps x deg. Obs. Max: 22.370 ° - FWHM: 0.251 ° - Raw Area: 13.76 Cps x deg. Obs. Max: 15.169 ° - FWHM: 0.211 ° - Raw Area: 17.13 Cps x deg.
Lin
(Cou
nts)
01002003004005006007008009001000110012001300140015001600170018001900200021002200230024002500260027002800290030003100320033003400
2-Theta - Scale
3 10 20 30 40 50 60 70 80
2th=
15.1
74 °
,d=5
.834
06
2th=
20.4
89 °
,d=4
.331
20
2th=
22.3
57 °
,d=3
.973
402t
h=23
.523
°,d
=3.7
7899
2th=
24.6
17 °
,d=3
.613
49
2th=
29.7
31 °
,d=3
.002
492t
h=30
.488
°,d
=2.9
2969
2th=
31.7
67 °
,d=2
.814
562t
h=32
.933
°,d
=2.7
1756
2th=
34.9
42 °
,d=2
.565
75
2th=
40.6
60 °
,d=2
.217
152t
h=41
.574
°,d
=2.1
7051
2th=
43.6
95 °
,d=2
.069
91
2th=
45.3
59 °
,d=1
.997
812t
h=46
.437
°,d
=1.9
5389
2th=
47.7
62 °
,d=1
.902
74
2th=
49.3
32 °
,d=1
.845
79
2th=
51.2
62 °
,d=1
.780
72
2th=
55.9
41 °
,d=1
.642
37
2th=
58.4
89 °
,d=1
.576
752t
h=59
.911
°,d
=1.5
4268
2th=
61.3
44 °
,d=1
.510
03
2th=
63.4
19 °
,d=1
.465
52
2th=
67.1
13 °
,d=1
.393
56
RESULTS FROM XRD• The general plot shows very less Intensity peak
areas for most of 2θ , though with some fluctuations.
• The area under the Intensity count is almost constant for most of the region.
• Peak areas change due to imperfect structure.• Peak values are changed due to absorption of light
by the structure of material.• The fluctuation in the graph is due to the
impurities.• This shows overall good crystalline properties.
RESULTS FROM FTIR• Transmittance is high for a wide range of wave no.• This means that the absorbance is quite low.• This shows presence of mostly very fine
nanoparticles.• The sharp bottoms represent the impurities.• This goes along with the properties expected of the
Zinc Selenide.• It can be used solar cells, lasers etc.
Intended Applications
• Early detection of breast cancer using total biochemical analysis of peripheral blood components: a preliminary study.
Cancer Detection• The aim of this study was to evaluate the feasibility of
detecting breast cancer by analyzing the total biochemical composition of plasma as well as peripheral blood mononuclear cells (PBMCs) using infrared spectroscopy.
• PBMCs and plasma were isolated and dried on a zinc selenide and measured under a Fourier transform infrared (FTIR) microscope to obtain their infrared absorption spectra. Differences in the spectra of PBMCs and plasma between the groups were analyzed as well as the specific influence of the relevant pathological characteristics of the cancer patients.
• Several bands in the FTIR spectra of both blood components significantly distinguished patients with and without cancer.
Conclusion In summary, ZnSe nanocrystals were successfully
synthesised by using solvo thermal route using Zinc Chloride, Ethylene Glycol, Hydrazine Hydrate ,which was further dried. Through this method, highly crystalline, well-dispersed ZnSe nanocrystal with an average diameter of 0.23 nm and a relatively narrow particle size distribution can be obtained. It is also expected that solvothermal method could be extended to synthesize the other semiconductor nanocrystals.
Further the results show its applicability in Cancer Detection and fabrication of Solar cells.
REFERENCES1. Chung Sua, Yi-Ting Hsieha, Chi Paib and I-Wen Suna - “Voltammetric Study of Selenium and Two-Stage
Electrodeposition of Photoelectrochemically Active Zinc Selenide Semiconductor Films in Ionic Liquid Zinc Chloride-1-Ethyl-3-Methylimidazolium Chloride” - Journal of Electrochemical Society 2015 volume 162, issue 7
2. Sandeep Arya, Saleem Khan, Parveen Lehana , Ishan Gupta, Suresh K - “Electrical properties of electrodeposited zinc selenide (ZnSe) nanowires”- Journal of Materials Science: Materials in Electronics -September 2014, Volume 25, Issue 9, pp 4150-4155
3. Biljana Pejova -” Optical phonons in nanostructured thin films composed by zincblende zinc selenide quantum dots in strong size-quantization regime: Competition between phonon confinement and strain-related effects” - Journal of Solid State Chemistry Volume 213, May 2014, Pages 22–31
4. Aparna C. Deshpandea, Shashi B. Singha, Majid Kazemian Abyaneha, Renu Pasrichab, 5. S.K. Kulkarni - Low temperature synthesis of ZnSe nanoparticles – 20086. Lin Yang, Lingyun Liu, Dingquan Xiao, Jianguo Zhu - Preparation and characterization of ZnSe nanocrystals by a
microemulsion-mediated method – 20117. Kyle H. Montgomery, Jong-Hyeok Jeon, Qiang Zhang, Maria C. Tamargo, Jerry M. Woodall- ZnSe: A Material to Improve
Efficiencies for Current Solar Cell Multi-junction Stacks - Materials Research Society Spring Meeting, April 13 – 17, 20098. Junli Xu a, , Wei Wanga, Xia Zhang a, Xinjuan Chang a, Zhongning Shi b, Geir Martin Haarberg c - Electrodeposition of ⇑
ZnSe thin film and its photocatalytic properties - Journal of Alloys and Compounds , January 20159. Udi Zelig, Eyal Barlev, Omri Bar, Itai Gross, Felix Flomen, Shaul Mordechai, Joseph Kapelushnik, Ilana Nathan,Hanoch
Kashtan, Nir Wasserberg,# and Osnat Madhala-Givon# - Early detection of breast cancer using total biochemical analysis of peripheral blood components: a preliminary study – BMC Cancer- May 2015
10. Shyam Ranjan Kumar,a Mohan Nuthalapatia and Joydeep Maity- Development of nanocrystalline ZnSe thin film through electrodeposition from a non aqeous solution, Scripta Materilia – May 2012
11. I.T. Zedan a, , A.A. Azabb, E.M. El-Menyawy b - Structural, morphological and optical ⁎properties of ZnSe quantum dot thin films, Spectrochimica Acta – October 2015
12. A.A. Khurram a, , Faisal Jabar b, M. Mumtaz b, Nawazish A. Khan c, M. Nasir ⇑Mehmood - Effect of light, medium and heavy ion irradiations on the structural and electrical properties of ZnSe thin films, Nuclear Instruments and Methods in Physics Research- August 2013
13. A.P. Pardo Gonzalez, H.G. Castro-Lora, L.D. López-Carreño, H.M. Martínez, N.J. Torres Salcedo - PhysicalpropertiesofZnSethin films depositedonglass and siliconsubstrates, Journal of Physics and Chemistry of Solids – January 2014
14. Steven C. Erwin, Lijun Zu, Michael I. Haftel, Alexander L. Efros, Thomas A. Kennedy & David J. Norris - Doping semiconductor nanocrystals, Nature – May 2005
15. Narayan Pradhan ,† David Goorskey ,‡ Jason Thessing ,† and Xiaogang Peng *† - An Alternative of CdSe Nanocrystal Emitters: Pure and Tunable Impurity Emissions in ZnSe Nanocrystals, J. Am. Chem. Soc., 2005, 127 (50), pp 17586–17587
16. Shinjita Acharya†, D. D. Sarma§, Nikhil R. Jana† and Narayan Pradhan*†‡ - An Alternate Route to High-Quality ZnSe and Mn-Doped ZnSe Nanocrystals, J. Phys. Chem. Lett., 2010, 1 (2), pp 485–488
