In order to clarify the fundamental luminescent mechanism of undoped and Er-doped ZnO thin films synthesized by sputtering method, cathodoluminescence (CL) from the samples formed on several kinds of substrate were measured. There was no explicit peak identified with luminescence from ZnO crystal defects in undoped sample, on the contrary, three sharp luminescent peaks were observed in the case of Er-doped ZnO film due to the internal transition of the additive Er ions in the CL spectrum. The mechanism was investigated in comparison with photoluminescence (PL).
Enhanced photocatalytic activity in Ag-nanoparticle-dispersed BaTiO3 composite thin films: Role of charge transfer