Fabrication of ZnO nanocrystals dispersed in glass films for low-temperature optical studies

Transparent ZnO-nanocrystal-dispersed glass films were successfully fabricated by a sol–gel method. Samples were characterized by transmission electron microscope and X-ray diffraction measurements, which show that the samples have good crystallinity. Optical properties of excitons confined in ZnO nanocrystals were studied by measuring absorption and photoluminescence (PL) spectra. Absorption due to free excitons was clearly observed and strong PL lines were observed in the UV region at around the exciton absorption energy.