A Comparison between the Electrical and Optical Properties of CdS: In Thin Films for Two Doping Ratios

Indium-doped cadmium sulphide CdS:In thin films were prepared by the spray pyrolysis (SP) technique on glass substrates at a substrate temperature Ts = 490°C. A comparison between the electrical and optical properties of the films for two different doping ratios was made through measuring and analyzing the transmittance curves, photoluminescence spectra (PL) and I-V plots. It was found that the higher doping ratio results in a decrease in the transmittance and PL signal, and a slight increase in the optical bandgap energy. Also it results in a considerable reduction of the resistvity of the films. So choosing the proper doping ratio is important to produce high quality CdS:In thin films suitable for the use as windows in CdS/CdTe solar cells.