Electronic structure calculations for ZnSxSe1−x

Energy band gaps and electron effective mass as well as their composition dependence are the most critical parameters for band structure calculations of semiconductor alloys. Therefore, an accurate knowledge of these parameters is very important. Unfortunately, there is a limited experimental and theoretical information in the literature regarding the electronic band parameters for zinc blende ZnSxSe1−x. This has incited us to carry out such calculations. For this purpose, we have used the empirical pseudo potential method within the Virtual Crystal Approximation and the effect of compositional disorder is treated as an effective potential. The band gap variation versus sulfur concentration x shows two different behaviors: clear diminution of gap energy for low concentrations, and quasi-linear behavior with a small bowing for large values of x. Furthermore, the calculated effective mass shows that the disorder is not only compositional but also structural.