Properties and efficiency of Cu2S-CdS sprayed layer photocells

The paper describes some electrooptical properties of CdS sprayed films and photocells related to their preparation conditions and structure. It is shown that the properties of CdS layers, made with solutions of CdCl2 and thiourea (S/Cd equals 1) and deposited on glass substrate at a substrate temperature of 380 C, are similar to those of evaporated layers, except for sensitivity to oxygen adsorption. The low layer resistivity observed after desorption may be due to doping with chlorine ions coming from residual CdCl2 and impurities. The backwall photocells exhibit efficiencies of about 4-5 percent. The use of purer initial material and a slight compensation are needed to produce better results by widening the space charge region. With CdZnS layers in place of pure CdS, a large increase in photovoltage can be obtained and efficiencies greater than 8 percent can be attained.