Preparation and characterization of zinc sulfide thin films through the sulfuration of sprayed zinc oxide thin films

In this study, the preparation of the zinc sulfide thin film by a substitution oxygen-sulfur inside sprayed ZnO compounds are investigated. First, the spray pyrolysis method has been used to grow the ZnO layers on glass substrates at 450 °C. The annealing process time was 12 hours. After a suitable cooling phase, the whole substrate-layer was introduced into a sealed tube. Consecutively, sulfur powder was introduced and vaporized under vacuum conditions inside the sealed tube containing the formerly ZnO prepared thin film. The structural properties of the prepared samples were characterized by X-ray diffraction (XRD) technique. We found that ZnS thin film have the cubic structure with a preferred orientation along (111) plane without any impurities and secondary phases. UV-VIS measurements show that the average transmittance of the ZnS thin films is between 63 and 73%. The optical band gaps for the ZnS and ZnO thin films were estimate too and it was 3.67 - 3.28 eV respectively.