A simple preparation technique of ZnO thin film with high crystallinity and UV luminescence intensity

In this study, the Zn thin films were evaporated on the glass substrates at room temperature (RT). Then the substrates were transferred into a thermal tube furnace to form the ZnO thin films. This oxidation processes were carried out in the air by two steps: 250 °C for 2 h and then 400, 450, 500, 550 or 600 °C for another 1 h. The X-ray diffraction (XRD) and the scanning electron microscopy (SEM) studies indicate that the ZnO thin film obtained at 500 °C has the best crystallinity. The RT photoluminescence (PL) measurements also show that the film oxidized at 500 °C exhibits the highest ultraviolet (UV) emission intensity at 370 nm with the narrowest full-width at half-maximum (FWHM) of 110 meV. By optimizing the process parameters of this simple technique, high quality ZnO thin films can be acquired.