Comparative first-principle analysis of un-doped and V3+-doped α-ZnAl2S4 spinel

The experimental and theoretical studies of the optical properties of pure α-ZnAl2S4 and α-ZnAl2S4:V3+ crystals were carried out. The ab initio and crystal field calculations of the structural and optical properties of α-ZnAl2S4:V3+ were compared with the corresponding experimental data. It was shown that the lowest vanadium 3d states are located at about 1.36 eV above the valence bandʹs top. The complete energy level scheme of the α-ZnAl2S4:V3+ system, which includes the hostʹs electronic band structure and impurity ionʹs energy levels, was suggested on the basis of the performed calculations.