Optical properties of ZnO thin film on γ-LiAlO 2 substrate grown by pulsed laser deposition

Abstract

Optical properties were investigated of ZnO thin films grown on (100) γ-LiAlO 2 (LAO) substrates by pulsed laser deposition method. C-axis oriented ZnO film was grown on (100) LAO substrate at the substrate temperature of 550 °C. The transmittances of the films were over 85%. Peaks attributed to excitons were seen in the absorption spectra, indicating that the thin films have high crystallinity. Photoluminescence spectra were observed at room temperature; the peak at 550 nm is ascribed to oxygen vacancies in the ZnO films caused by the diffusion of Li from the substrate into the film during deposition.