Oxygen Ratio Effect on Zinc Oxide Films Fabricated by Radio Frequency Magnetron Sputtering for Photoluminescence Type Gas Sensor Application

ZnO thin films were used for fabricating ZnO nanostructures using a novel reducing annealing method. The effect of oxygen ratio on the structural property of ZnO film and further influence on the forming nanostructures were investigated. ZnO thin film with high crystallinity was obtained from the deposition introducing oxygen ratio of 75%. The good crystallinity of ZnO film also contributed to well-controllable vertical aligned ZnO nanostructures during reducing annealing process. The optimized reducing annealing condition for high density of ZnO nanostructures with much oxygen vacancies was reducing annealing process with pre-annealing at 400 °C The obtained ZnO nanostructures showed the photoluminescence sensitivity for hydrogen gas at 300 °C.