Temperature dependence of the band gap of ZnSe1−xOx

We have studied the temperature dependence of the band gap of molecular-beam-epitaxy-grown ZnSe1−xOx films (x=0–0.021) using photoluminescence spectroscopy from 15 to 280 K. The temperature dependence of the band gap decreases with increasing oxygen concentration, which can be quantitatively explained by an anticrossing interaction between the highly localized oxygen defect states and the extended states of the conduction band.