Gamma-ray irradiation and the alterations in photoluminescence emissions of undoped and indium-doped ZnO single crystals

We investigate the effect of gamma-ray irradiation on the ultraviolet (UV) emissions of undoped and indiumdoped zinc oxide (ZnO) single crystals. After irradiation, UV emission broadening is observed which is attributed to shallow defects induced in the strained crystal lattice. These defect states play a role in shortening the UV emission lifetimes, and the difference is found to be more pronounced in the doped ZnO crystal. The underlying phenomena responsible for the observed changes in the photoluminescence properties are discussed.