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Characterisation of CdS/CdTe heterojunction solar cells by current-voltage measurements at various temperatures under illumination
Author(s)
Gaewdang, Thitinai
Wongcharoen, Ngamnit
Wongcharoen, Tiparatana
Date Issued
May 8, 2012
Type
Conference Paper
Abstract
Heterojunction CdS/CdTe thin film solar cells were fabricated with a superstate structure consisting of the successive layers: soda lime glass/ITO/CdS/CdTe/back contact. ZnTe:Cu films were deposited on the back surface of the CdTe layer presenting as ohmic back contact. The substrate was soda lime glass coated with ITO films by rf magnetron sputtering serving as the transparent front contact. A thin layer of CdS with thickness about 80 nm was applied by chemical bath deposition. Close-spaced sublimation of the CdTe films was accomplished by placing a CdTe source in a close proximity (6 mm) to the substrate in vacuum chamber with low pressure about 3×10 -2 mbar. The source was heated to 550 °C and the substrate to 450 °C. This arrangement causes Cd and Te to sublime from source and diffuse to the substrate. The fabricated cells were investigated using current-voltage (I-V) in the temperature range 20-300 K under a standard AM1.5 illumination in order to define the transport mechanism in the heterojunction. Tunnelling enhanced interface recombination has been found to dominate carrier transport mechanism in the junction at all investigated temperatures. © 2011 Published by Elsevier Ltd.
Citation
Energy Procedia, 15, 299-304, 2012