Please use this identifier to cite or link to this item:
http://repository.kln.ac.lk/handle/123456789/11248
Title: | Growth of CdS and CdTe thin film semiconductors and fabrication of CdS/CdTe solar cells |
Authors: | Kumarasinghe, K.D.M.S.P.K. de Silva, D.S.M. Pathiratne, K.A.S. Dharmadasa, I.M. Salim, H.I. Abdul-Manaf, N.A. Ravirajan, P. Balashangar, K. |
Keywords: | Thin films Semiconductors Solar cells |
Issue Date: | 2015 |
Publisher: | Faculty of Graduate Studies, University of Kelaniya |
Citation: | Kumarasinghe, K.D.M.S.P.K., De Silva, D.S.M., Pathiratne, K.A.S., Dharmadasa, I.M., Salim, H.I., Abdul-Manaf, N.A., Ravirajan, P. and Balashangar, K. 2015. Growth of CdS and CdTe thin film semiconductors and fabrication of CdS/CdTe solar cells, p. 194, In: Proceedings of the International Postgraduate Research Conference 2015 University of Kelaniya, Kelaniya, Sri Lanka, (Abstract), 339 pp. |
Abstract: | Thin films of CdS and CdTe semiconductor materials were electrodeposited onto glass/fluorine doped tin oxide conducting glass surfaces using a potentiostat/galvanostat equipped with a three electrode cell. Aqueous electrolytic bath containing CdCl2 and (NH4)2S2O3 was used for the electrodeposition of CdS thin films. CdTe thin films were electrodeposited onto glass/FTO/CdS substrates from aqueous solution having high concentrations of CdSO4 and low concentrations of TeO2 and CdCl2. The glass/FTO/CdS/CdTe/Cu-Au solar cell devices were prepared by thermal evaporation of Cu and Au on CdTe surface. CdS films grown were annealed at ~400 °C for 15 minutes in air and photo-electro chemical (PEC) cell measurements were performed to identify the electrical conductivity type. Both as-deposited and annealed CdS layers were identified as n-type in electrical conduction. CdS thin films were shown enhanced PEC responses upon heat treatment. The respective band gap values for as-deposited and heat treated CdS were 2.35±0.05 eV and 2.40±0.05 eV which were close to the band gap of bulk CdS. XRD analysis of as-deposited CdS layers revealed the presence of hexagonal CdS materials with the major peak arising from (002) plane. Following the CdTe deposition on glass/FTO/CdS substrate, the surface of CdTe layers were coated with a 0.1% CdCl2 solution and structures were annealed at ~400°C for 10 minutes in air. Band gaps for CdTe layers were found to be 1.45±0.02 eV for both as-deposited and annealed samples which exhibited the band gap of bulk CdTe. There was a little improvement in cubic (220) and (311) peaks of XRD spectra of annealed CdTe layers compared to the as-deposited material, but annealing exhibited a small reduction of cubic phase preferential orientation (111). SEM images showed that CdS and CdTe layers were fairly uniform. The fabricated solar cell devices showed the efficiency of 2.1% with Voc ~330 mV, Jsc~20 mA cm-2 and FF~33% under the illumination of air mass (AM) 1.5 conditions (100 mW/cm2, 1 Sun). |
URI: | http://repository.kln.ac.lk/handle/123456789/11248 |
Appears in Collections: | IPRC - 2015 |
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