Design analysis of the thin-film CdS—Cu2S solar cell

A detailed model of the CdS-Cu2S solar cell was used to analyze design limits of cell configurations based on present laboratory technology. The parameters controlling the short-circuit current, open-circuit voltage, and fill factor are treated. The limits for each of these factors is obtained. The results indicate that the attainable conversion efficiency of the CdS-Cu2S solar cell extrapolating from the present processing technology is roughly 10 percent, as compared to a theoretical efficiency of 16 percent, if no losses occurred. A similar analysis for a cell using Cd1-xZnxS in place of CdS yields an attainable efficiency of 15 percent and a theoretical efficiency of over 26 percent. The model identifies those processing parameters which must be improved in order to optimize cell efficiency. Once technology is improved, the processing parameters will be reassessed with an aim towards increasing the maximum attainable efficiency.