Effect of Vanadium doping on optoelectronic and magnetic properties of wurtzite ZnS crystal

In this work, we use the density functional theory calculations to explore the effect of vanadium doping on optoelectronic and magnetic properties of wurtzite ZnS. The calculation results reveal that V-doped ZnS favors spin-polarized state with the total magnetization of 3.0 μ_B per supercell. The ferromagnetic interaction between V spins in the lattice of ZnS is due to double exchange mechanism. Moreover, optical absorptions of undoped and doped systems were discussed and we found that the intensity of the main absorption peak of undoped ZnS becomes weak on V substitution. The spin-allowed d-d absorption peaks of V ions were observed in the near Infra-red light (NIR) and Visible light regions (VIs). The intensity of the intraband d-d absorption increases as the doping concentration increases. The correlation between the fundamental bandgap and the magnetic coupling between V spins shows that the AFM and FM coupled ions increases and decreases the fundamental bandgap, respectively. The results of optical and magnetic properties are interesting from a theoretical point of view and may open opportunities for V; ZnS in optoelectronic and spintronic devices.