Electronic structures and optical properties of ZrS2 monolayer by n- and p-type doping

Based on density functional theory, the electronic structures and optical properties of ZrS2 monolayer doped with group V and VII atoms are investigated, where dopants are incorporated by substituting S atom. We find pristine ZrS2 monolayer is semiconductor with indirect band gap of 1.109eV, however for As-doping ZrS2 monolayer, magnetic moment is induced and exhibits half-metallic feature. The formation energy increases with increasing impurity atom size for each doped case and it is relatively easier to incorporate impurity atoms under Zr-rich experimental situation. Numerical results also suggest that N-, P- or As-doping is effective for p-type conductivity, while F, Cl, Br and I impurities are suitable as n-type carriers. From the optical parameters we have obtained, one can conclude the pristine and doped ZrS2 monolayers are transparent and which will be more transparent when the incident light frequency increases. Meanwhile, absorption effect of ultraviolet light enhances with the increase of incident light energy and the absorption edge occurs red shift phenomenon in each doped system. Our finding offers a meaningful routine for designing electronic spin devices, UV photodetector and UV filter.