Commercial polyethylene terephthalate (PET) film has been used as flexible substrate, and chalcogenide materials such as CdS, ZnS have been coated separately on PET film using vacuum thermal evaporation method. The structural characterisation of CdS-PET and ZnS-PET films has been performed by X-ray diffraction (XRD) pattern and Fourier transforms infrared (FTIR) spectroscopy. The surface morphology of CdS-PET and ZnS-PET films has also been investigated using scanning electron microscope (SEM). Temperature dependent mechanical study of chalcogenide-PET films has been carried out using Dynamic Mechanical Analyser (DMA). The stress-strain curves of chalcogenide coated PET films at room and elevated temperatures explain the mechanical response of these films under the different temperature. 1. Introduction Metal chalcogenides (sulfides, tellurides, and selenides) are of great importance for researchers because they are potential candidates for optoelectronic applications such as photodetectors, solar cells, and thin film transistor [1–6]. CdS thin films are regarded as one of the most promising materials for heterojunction thin film solar cells. Wide band CdS has been used as the window material together with several semiconductors such as CdTe, Cu2S, InP, and CuInSe2 with 14–16% efficiency [7, 8]. ZnS thin film has also potential applications in optoelectronic devices such as blue light emitting diodes [9], electroluminescence devices, and photovoltaic cells which enable wide application in the field of displays [10, 11], sensors, and lasers [12]. As the metallized polymer films are used in flexible optoelectronic devices, it is proved by Gupta et al. [13] that most of the metals show excellent adhesion with PET film with the help of stress-strain curves of metalized polymer film for a wide range of temperatures; therefore in the same way an effort has been made to see the effect of wide range of temperatures on chalcogenide (CdS, ZnS) coated polymer film. The change in mechanical stability, stiffness, and elasticity of chalcogenide coated polymer films with temperature is also important issue of study for the application point of view. The mechanical studies of CdS and ZnS coated polymer systems at elevated temperatures are very important for the development of light weight optoelectronic devices. In the present work polyethylene terephthalate (PET) film is used as flexible substrate because of its high mechanical strength. Many techniques have been reported for the deposition of CdS and ZnS thin films. These include evaporation, sputtering, chemical
References
[1]
P. C. DeHart, D. S. Albin, A. Duda et al., in Proceedings of the 17th European Photovoltaic Solar Energy Conference, Munich, Germany, October 2001.
[2]
K. Nair, M. T. S. Nair, A. Fernandez, and M. Ocampo, “Prospects of chemically deposited metal chalcogenide thin films for solar control applications,” Journal of Physics D, vol. 22, no. 6, p. 829, 1989.
[3]
Y. Ueno, H. Minoura, T. Nishikawa, and M. Tsuiki, “Electrophoretically deposited CdS and CdSe anodes for photoelectrochemical cells,” Journal of the Electrochemical Society, vol. 130, no. 1, pp. 43–47, 1983.
[4]
C. Na？cu, I. Pop, V. Ionescu, E. Indrea, and I. Bratu, “Spray pyrolysis deposition of CuS thin films,” Materials Letters, vol. 32, no. 2-3, pp. 73–77, 1997.
[5]
J. Touskova, D. Kindl, and J. Tousek, “Photovoltaic cells on CdS/CdTe heterojunctions,” Physica Status Solidi (A) Applied Research, vol. 142, no. 2, pp. 539–549, 1994.
[6]
M. A. Hasse, J. Qiu, J. M. DePuydt, and H. Cheng, “Blue-green laser diodes,” Applied Physics Letters, vol. 59, no. 11, p. 1272, 1991.
[7]
B. Su and K. L. Choy, “Microstructure and properties of the CdS thin films prepared by electrostatic spray assisted vapour deposition (ESAVD) method,” Thin Solid Films, vol. 359, no. 2, pp. 160–164, 2000.
[8]
X. Wu, J. C. Keane, R. G. Dhere et al., “16.5% efficient CdS/CdTe polycrystalline thin-film solar cell,” in Proccedings of the 17th European Photovoltaic Solar Energy Conference, pp. 995–1000, Munich, Germany, October 2001.
[9]
S. Coe, W. K. Woo, M. Bawendi, and V. Bulovi？, “Electroluminescence from single monolayers of nanocrystals in molecular organic devices,” Nature, vol. 420, no. 6917, pp. 800–803, 2002.
[10]
M. C. Beard, G. M. Turner, and C. A. Schmuttenmaer, “Size-dependent photoconductivity in CdSe nanoparticles as measured by time-resolved terahertz spectroscopy,” Nano Letters, vol. 2, no. 9, pp. 983–987, 2002.
[11]
R. P. Raffaelle, S. L. Castro, A. F. Hepp, and S. G. Bailey, “Quantum dot solar cells,” Progress in Photovoltaics: Research and Applications, vol. 10, no. 6, pp. 433–439, 2002.
[12]
V. I. Klimov, A. A. Mikhailovsky, S. Xu et al., “Optical gain and stimulated emission in nanocrystal quantum dots,” Science, vol. 290, no. 5490, pp. 314–317, 2000.
[13]
S. Gupta, M. Dixit, K. Sharma, and N. S. Saxena, “Mechanical study of metallized polyethylene terephthalate (PET) films,” Surface and Coatings Technology, vol. 204, no. 5, pp. 661–666, 2009.
[14]
S. Gupta, D. Patidar, N. S. Saxena, K. Sharma, and T. P. Sharma, “Electrical study of Cu-CdS and Zn-CdS schottky junctions,” Optoelectronics and Advanced Materials, Rapid Communications, vol. 2, no. 4, pp. 205–208, 2008.
[15]
H. Uda, H. Yonezawa, Y. Ohtsubo, M. Kosaka, and H. Sonomura, “Thin CdS films prepared by metalorganic chemical vapor deposition,” Solar Energy Materials and Solar Cells, vol. 75, no. 1-2, pp. 219–226, 2003.
[16]
K. Anuar, Z. Zulkarnain, N. Saravanan, M. Nazri, and R. Sharin, “Effects of electrodeposition periods and solution temperatures towards theproperties of CdS thin films prepared in the presence of sodium Tartrate,” Materials Science, vol. 11, no. 2, pp. 101–104, 2005.
[17]
J. H. Lee and D. J. Lee, “Effects of CdCl2 treatment on the properties of CdS films prepared by r.f. magnetron sputtering,” Thin Solid Films, vol. 515, no. 15, pp. 6055–6059, 2007.
[18]
P. P. Sahay, R. K. Nath, and S. Tewari, “Optical properties of thermally evaporated CdS thin films,” Crystal Research and Technology, vol. 42, no. 3, pp. 275–280, 2007.
[19]
S. Gupta, V. Shaktawat, K. Sharma, N. S. Saxena, and T. P. Sharma, “Mechanical property of CdS coated PET and mica films,” AIP Conference Proceedings, vol. 1004, no. 1, pp. 328–333.
[20]
M. Dixit, V. Shaktawat, K. Sharma, N. S. Saxena, and T. P. Sharma, “Mechanical characterization of polymethyl methacrylate and polycarbonate blends,” AIP Conference Proceedings, vol. 1004, no. 1, pp. 311–315.
[21]
K. Menard, Dynamic Mechanical Analysis: A Practical Introduction, CRC Press, Boca Raton, Fla, USA, 1999.
[22]
W. D. J. Callister, “Characteristics, applications and processing of polymers,” in Materials Science and Engineering: An Introduction, W. D. J. Callister and D. G. Rethwisch, Eds., John Wiley & Sons, 2000.
[23]
C. R. Martins, Y. M. De Almeida, G. C. Do Nascimento, and W. M. De Azevedo, “Metal nanoparticles incorporation during the photopolymerization of polypyrrole,” Journal of Materials Science, vol. 41, no. 22, pp. 7413–7418, 2006.
[24]
P. Ziegler, M. F. Vallat, H. Haidara, and J. Schultz, “Polyester/aluminium adhesion: improvement by heat treatments,” Journal of Materials Science, vol. 32, no. 7, pp. 1809–1813, 1997.
[25]
S. Lalitha, R. Sathyamoorthy, S. Senthilarasu, A. Subbarayan, and K. Natarajan, “Characterization of CdTe thin film—dependence of structural and optical properties on temperature and thickness,” Solar Energy Materials and Solar Cells, vol. 82, no. 1-2, pp. 187–199, 2004.
[26]
M. Baboo, M. Dixit, K. Sharma, and N. S. Saxena, “The Structure and thermomechanical properties of blends of trans-polyisoprene with cis-polyisopren,” International Journal of Polymeric Materials, vol. 58, no. 12, pp. 636–646, 2009.
[27]
D. Singh, K. Singh, G. Singh et al., “Optical and structural properties of ZnO-PbO-B2O3 and ZnO-PbO-B2O3-SiO2 glasses,” Journal of Physics: Condensed Matter, vol. 20, no. 7, Article ID 075228, 2008.
[28]
R. R. Singh, D. Kaushik, M. Sharma, D. K. Gupta, and R. K. Pandey, “Studies on surface processing and passivation of p-Hg1？xCdxTe,” Semiconductor Science and Technology, vol. 23, no. 1, Article ID 015016, 2008.
[29]
Z. B. Sun, X. Z. Dong, W. Q. Chen, S. Shoji, X. M. Duan, and S. Kawata, “Two- and three-dimensional micro/nanostructure patterning of CdS-polymer nanocomposites with a laser interference technique and in situ synthesis,” Nanotechnology, vol. 19, no. 3, Article ID 035611, 2008.
