First-principles study on the electronic structure, magnetic and optical properties of strain regulated (V, Mn) co-doped HfS2 monolayer

The impact of biaxial strain on the electronic structure, magnetic and optical properties of double impurity co-doped HfS2 monolayers was investigated using first principles methods. The findings indicate that (V, Mn) co-doped HfS2 monolayer behaves as a dilute magnetic semiconductor both before and after the application of strain, with its magnetism attributed to the hybridization of V:3d, Mn:3d, and S:3p orbitals. In the biaxial strain range of -5% to 5%, the ferromagnetism remains unchanged, the band gap decreases with the increase of compressive strain. In contrast, tensile strain leads to an increase in both the band gap. Finally, our analysis of optical properties reveals that (V, Mn) co-doped HfS2 monolayer enhances infrared light absorption coefficient, compressive strains further enhance this absorption coefficient. These results indicate that (V, Mn) co-doped HfS2 monolayer by strain regulation is an effective strategy for designing dilute magnetic semiconductors and optoelectronic devices.