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[摘要]：Polycrystalline CdTe and CdS films were prepared by thermal evaporation technique with thicknesses 1.0 mu m and 0.1 mu m, respectively The prepared films were deposited at substrate temperature 423 K, then annealed under vacuum at various annealing temperatures. Anisotype CdS/CdTe heterojunction has been prepared. The structure of the films was examined by X-ray diffraction. Hall measurements confirmed the conductivity types for CdTe and CdS to be p- and n-, respectively. Electrical characteristics of the junction (C-V and I-V measurements) showed that the junction was abrupt. Heat treatment (T-a) of the junction caused a decrease in the capacitance with increasing the reverse bias voltage. Also, both zero bias capacitance and built in voltage are decreased with increasing T-a. Carrier concentration around the junction was increased with increasing T-a. Transport mechanism of forward current coincides to tunneling-recombination mechanism; this was confirmed by I-V measurement. (C) 2009 Elsevier Ltd. All rights reserved. |
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