Correlation of oxygen defects variations to band gap changes in luminescence properties of SrZnO_2: 0.02 Eu~(3+) phosphors

摘要

The SrZnO2: 0.02 Eu3+ phosphors were prepared by conventional solid-state reactions in O-2, air, N-2 and Ar, respectively. X-ray photoelectron spectroscopy analyses show that the concentration of oxygen defects in samples change obviously under different atmospheres. From the data collected by UV-vis diffuse reflectance spectroscopy and the fluorescence spectra, it is found that Vo and oxygen interstitials can diminish band gaps of samples, promoting an increase in photoluminescence intensities of samples on the based of host-sensitized luminescence effect, in which the effect of oxygen vacancies is stronger than that of oxygen interstitials. The mechanism of band gap narrowing has been explained in detail. (C) 2019 Elsevier B.V. All rights reserved.