In this work, zinc oxide (ZnO) thin films were synthesized by thermal oxidation of zinc selenide films in oxygen atmosphere without introducing any catalysts or additives. According to the X-ray diffraction and morphology analysis, the ZnO films were hexagonal wurtzite structure, indicating the high crystalline quality. Strong emission peak at around 370 nm (ultraviolet) and weak emission peak at 525 nm (green) were observed in the photoluminescence spectra. The dependence of photoluminescence intensity on annealing conditions was investigated in the experiment. With the increase of annealing temperature and time, the photoluminescence intensity reached a peak at 450 degrees C for 45 min in oxygen, which was considered to be the optimal condition. (C) 2017 Elsevier B.V. All rights reserved.