Preparation and characterization of ZnS thin films by chemical bath deposition and electron-beam evaporation

Zinc sulphide thin films were prepared by chemical bath deposition (CBD) and the properties of these films are compared with those deposited by Physical vapour deposition (PVD). The variation in the optical and electrical properties of the CBD grown ZnS films with the pH of the reaction mixture was investigated. The chemically deposited ZnS films showed a wide band gap of 3.93eV and a transparency of more than 80% in the visible region. The lowest resistivity of ~104 Ωcm was obtained for the films prepared from a chemical bath of pH 10.6. The refractive index, extinction coefficient and the dielectric constants of CBD ZnS films are also reported.