ZnxCd1?xS/Cu2S heterojunction solar cells—I: Fabrication and performance

Alloy films of Zn_xCd_1?xS have been prepared by both vacuum evaporation and spray pyrolysis. Junctions of these films with Cu₂S have been formed by the solid state reaction for the evaporated alloy films and by the conventional chemiplating technique for the spray deposited alloy films. The current-voltage characteristics, diffusion length of minority carriers and spectral response of the cells have been determined. Highest conversion efficiency for the evaporated cells is 6.5% corresponding to x = 0 and for the sprayed cells is 5.6% corresponding to x = 0.1. The cell performance has been analysed and further scope of improvement indicated.