Effect of oxygen vacancy on electronic structure and optical spectra of SrO crystal

Abstract

Intrinsic defects affect the electronic structure and optical properties of crystals, so their identification is crucial to develop device technology materials. The SrO crystal is an important basic chemical raw material which has attracted special interests as basic heterogeneous catalyst recently. In this work, we used first-principles calculation to study the effect of oxygen vacancy on the electronic structure and optical spectra of SrO crystals. In order to get more accurate results, finite-size correction scheme was employed to correct the defect formation energy and hybrid density functional was performed to reproduce the band gap. We found that V0 introduces a deep impurity level which causing a red shift of the absorption spectrum in SrO crystals. The optical absorption band of F and F+ color centers peak at 2.49eV and 3.06eV, respectively, which are consistent with the experimental results. Meanwhile, the optical emission bands calculated for F and F+ color centers in SrO crystals peak at 2.14 eV and 2.50 eV, respectively. We predict that photoluminescence bands peaks at 554 nm (2.24eV) may be attributed to the F centers and the green emission in SrO crystal (514 nm, 2.53eV) may be caused by F+ centers. Our study will benefit to the apply and design of the novel SrO crystal.