Study of the structure and optical properties of Cu and Mn in situ doped ZnS films by chemical bath deposition

The in situ doping of ZnS films with Cu and Mn ions was obtained by the chemical bath deposition method. The resulting films, with cubic crystalline structure, were specular, adherent, and optically transparent. The analysis from X-ray photoelectron spectroscopy confirmed the effective insertion of Cu and Mn ions and the formation of defects in the crystalline structure of the ZnS films. Moreover, the morphology analysis showed that the presence of the doping ions in the reaction solution promoted the deposition of films with better uniformity. The effects of the doping agents in the optical properties of the ZnS films were also analyzed. First of all, it was observed a red-shift of the optical absorption edge, and therefore, the decrease of the optical band gap. Afterwards, the room-temperature photoluminescence spectroscopy confirmed the effective activation of the ZnS film with Cu and Mn ions, when the luminescence emission centered at 470 nm was shifted to longer wavelengths (green-orange emissions centered at 530 nm). Based in these results, it is concluded that the process reported here could be used as an original alternative for the preparation of ZnS films with a mixture of other doping agents.