IDENTIFICATION OF THE IMPURITY PHASE IN CHEMICALLY DEPOSITED CDS THIN-FILMS

Identification of the impurity phase present in chemically deposited C dS thin films and in the precipitate used for screen printing CdS/CdTe solar cells is reported in this paper. X-ray diffraction (XRD) studie s of the films and the precipitate showed that the impurity phase is a mixture of cadmium oxide sulphate (Cd3O2SO4) and cadmium oxide (CdO). Analysis of the films and the powders obtained using thiourea (TU) an d thioacetamide (TA) as sulphurising agents showed that the impurity p hase is predominantly present when TU is used in the chemical bath. Th e high conductivity shown by chemically CdS films (using TU) when anne aled at higher temperatures in air is attributed to the predominance o f the conducting CdO phase in the film.