Photoluminescence and XPS analyses of Mn2+ doped ZnS nanocrystals embedded in sol–gel derived hybrid coatings

Photoluminescence and X-ray photoelectron spectroscopy studies of Mn2+ doped ZnS nanocrystals in inorganic–organic hybrid coatings prepared by a sol–gel process are presented. A 25-fold enhancement of photoluminescence was observed after UV irradiation for 6 h in an ambient atmosphere. X-ray photoelectron spectroscopy results indicate a chemical shift of binding energy from ZnS to ZnSO4 after UV irradiation. X-ray diffraction results show a decrease of ZnS nanocrystal size during UV irradiation. The cause of these phenomena was discussed based on a photochemical reaction on ZnS nanocrystal surface.