Two-stage chemical bath deposition for well-covered and stoichiometric ZnS thin films

A two-stage chemical bath deposition (CBD) was reported to modify the thin film deposition of zinc sulfide (ZnS) material, which is a promising candidate as a buffer layer in chalcopyrite solar cells. During the proposed process, two bath temperatures were used subsequently: substrates were immersed in the bath with temperature 85°C for first-stage deposition, followed by the bath with temperature 70°C for the second-stage deposition. As a result, the ZnS film deposited by the proposed two-stage CBD process demonstrated the more desirable film coverage and stoichiometric Zn/S ratio on the soda lime glass substrate than the one without.