CDS-CUXS HETEROJUNCTIONS PRODUCED BY SPUTTERING,R.F.

The object of this study is to produce thin film solar cells by reactive r.f. sputtering, using argon as the sputter gas and H2 as the reactive addition. The cells consist of the semiconductor materials CdS and CuxS which were available in the form of nearly stoichiometric targets. The CdS layer grows in a polycrystalline way with columnar grains of very small diameter. Its thickness could be reduced to 6 μm. The effect of sputtering parameters, such as gas composition, substrate temperature and bias voltage on the optical, electrical and structural properties of the individual layers and those of the heterojunctions were investigated. Optimization of these parameters resulted in an efficiency of 1%. In addition, several heterojunctions were produced by the known exchange reaction of cadmium and copper when the CdS layer is immersed into an aqueous chloride solution. In this case, after optimizing the parameters for the sputtering and dipping process, an efficiency of 0.8% was reached using the same CdS layer thickness of 6 μm. © 1979.