Tuning magnetic and optical properties of monolayer WSe2 by doping C, N, P, O, S, F, and Cl: First principles study

Nonmetal (NM) doping is a promising method to functionalize WSe2. In this work, the electronic, magnetic, and optical properties of NM (C, N, P, O, S, F, and Cl) doped monolayer WSe2 are systematically investigated by first principles study. It is found that NM atoms prefer to occupy at Se sites rather than interstitial positions. A general odd-even rule is proposed for NM doping to regulate magnetic properties, that is, doping with NM with an odd (or even) number of valence electrons will (or not) induce a magnetic moment in WSe2. More importantly, N doping increases the infrared (IR) light absorption area of WSe2 by 10.46 times. The reason is that the impurity level appearing above the valence band maximum increases light absorption. This work will provide a theoretical guidance for promoting the application of monolayer WSe2 in spintronic devices and optoelectronic devices.