Electronic structures and magnetic properties in nonmetallic element substituted MoS2 monolayer

Based on density functional theory using ab initio calculations, the electronic structure and magnetic properties of the B-, C-, N-, O-, F-, Cl-, Br-, and I-doped MoS2 monolayer are investigated. The B-, C-, and N-doped systems are p-type doping, while the halogen-doped systems are n-type doping. C-doping leads fairly deep and highly localized states in the gap of MoS2 without spin-splitting. O-doping result in a narrower band-gap for MoS2. At the PBE level, results show that all the doped systems, expect for C-doping and O-doping, exhibit half-metallic behaviors with a total magnetic moment of similar to 1.0 mu B. At the HSE level, the Br-doped case remains half-metallic, while the other doped cases revert to magnetic semiconductor. The magnetic moment mainly comes from the unpaired Mo-4d orbitals and the p orbital of the dopant, as well as the S-3p states. The formation of local magnetic moment depend on the local structure around the dopant, the localization of Mo-4d, variable valency of Mo cation, and the partially filled anion-p orbitals of the dopant itself. The long-range half-metallic ferromagnetic order is attributed to the double-exchange interactions. (C) 2015 Elsevier B. V. All rights reserved.