The phase of CuxS in the CdS-CuxS photovoltaic cell

Abstract

Photovoltaic cells have been prepared by immersing single crystals and evaporated layers of cadmium sulphide in a hot aqueous solution containing cuprous ions, at varying temperatures. Poor efficiency is obtained if cells are plated between 20 and 70 degrees C. The photovoltaic sensitivity increases dramatically with increasing plating temperature in the range 80-90 degrees C, and then more slowly with further increase in that parameter. A study of as-plated crystals using the technique of reflection electron diffraction has shown that the CdS layer is formed with the chalcocite phase, Cu₂S, when the high plating temperatures are used, whereas the djurleite phase Cu_1.96S is formed at lower temperatures. A cell with a layer of chalcocite has a major band of sensitivity at 0.90 mu m in contrast with a cell with a layer of djurleite which has a major band of sensitivity at 0.70 mu m.