High-quality ZnO thin film grown on sapphire by hydrothermal method

High-quality ZnO thin film was grown on (0001) sapphire substrate with a ZnO buffer layer by hydrothermal method under atmospheric pressure. The flat surface of the ZnO film was observed by SEM, and the wurtzite crystalline structure and preferred (0001) orientation of the ZnO film was observed by X-ray diffraction. Raman scattering and photoluminescence verified low density of impurities and defects. Test results overall demonstrate the proposed method simply and effectively synthesizes high-quality ZnO film. (C) 2015 Elsevier B.V. All rights reserved.