Band gap energy of ZnO x Se 1− x over the entire composition range

A model predicting the band gap energy of ZnOxSe1−x over the entire composition range is set up. It is found that the model can provide a good description for the band gap energy of ZnOxSe1−x. It is also found that the physical mechanisms for the band gap evolution in different composition ranges are different. Although the physical mechanism for the band gap evolution in the Se-rich region differs from that in the O-rich region, the difference between the band gap reductions in the Se-rich and O-rich regions is not large. In addition, it is found that the band gap bowing in the middle composition region is smaller than that in the Se-rich and O-rich regions. The reason is that the middle composition region lies in the bandlike region while the Se-rich and the O-rich composition regions lie in the impurity-like region.