First-principles study of the magnetic and optical properties of PtSe2 doped with halogen elements F, Cl, and Br

The electronic structure, magnetic and optical properties of halogen-doped two dimensional PtSe2 are investigated by using the first-principles ultra-soft pseudopotential plane wave method based on density functional theory. It is shown that the doped PtSe2 is more stable under Bottom-Se conditions than under Top-Se conditions, and the higher the doping concentration (C-d), the lower the band gap. At C-d = 5.56%, the Cl- and Br-doped PtSe2 are transformed from a non-magnetic semiconductor to a magnetic n-type semiconductor with a magnetic moment (M-B) of 1 mu B; while neither the F-doped PtSe2 nor the pristine PtSe2 is magnetic. When C-d = 11.1%, the F-doped PtSe2 at the first neighborhood becomes magnetic metal with M-B = 1.39 mu B; while that doped at the second nearest neighbor retains a semiconductor with M-B = 0. Thus Cl- and Br-doped PtSe2, as well as the first-neighbor F-doped PtSe2 can be well applied in spintronic devices. The optical properties are enhanced for all three doping systems with an obvious peak appearing in the infrared light region. Absorption and reflectivity curve still has a peak in the infrared light region.