Tight binding calculation of electronic properties of ternary alloy ZnS_xSe_1-x

Using an sp₃s* empirical tight binding method, we calculate energy band gap and electronic band structure of the zinc-blende ternary alloy ZnS_xSe_1-x. The band gap composition is calculated using an extended version of the virtual crystal approximation, which introduce an empirical correction factor that takes into account the non-linear dependence of the band gap with the composition. The results compare well with the experimental data. The ionicity character and the refractive index are also calculated.