Steady semiconducting properties of PtSe2 monolayer under non-metal atom and transition metal atom doping
Based on density functional theory, the electronic structure and magnetic properties of PtSe2 monolayer doped by different atoms were studied. The Pt and Se atoms are replaced by transition metal atom (Mn) and non-metal atom X (X=N, P, As), respectively. The pristine PtSe2 monolayer is semiconductor with indirect band gap of 1.352eV. For one non-metal atom doping, the doped systems exhibits indirect band gap magnetic semiconducting properties and the magnetic moment is less than 1µB and mainly comes from the hybridization of Pt-5d and X-p orbit. N-doped system still keeps magnetic semiconducting properties under strain (from -10% to 13%) and the band gap varies from 0.059eV to 1.308eV. For two X doped systems, three different configurations are considered. The doped systems keep indirect band gap semiconducting properties except for the third nearest neighbor N-doped (direct band gap). But for all of N-doped and the second nearest neighbor P-doped systems, the magnetic moment increases to more than double. Meanwhile, all of X-doped PtSe2 monolayer systems exhibits p-type semiconducting characteristics. For (Mn, X) co-doped systems, the magnetic moments are mainly localized in Mn 3d orbital and there is strong p-d hybridization between Mn atom and X atoms. (Mn, N/P) co-doped system still exhibits magnetic semiconducting properties. These results are important for designing semiconductor devices, electronic spin devices based on PtSe2 monolayer.