S-Site Substitution Effects on the Structural and Electronic Properties by O, Se, and Te in Monolayer MoS²: First-Principles Calculations

Abstract: We use first-principles calculations density-functional theory to investigate the S-site substitution effects on the structural and electronic properties in monolayer MoS² by O, Se, and Te. The calculated structural parameters show that the changed bond lengths are caused by the different electronegativity and atomic radius. The obtained formation energies indicate that the O doping is exothermic, but the others dopings are endothermic. The electronic structures show that there is a direct-indirect band gap transition from pure monolayer MoS² to chalcogen-doping monolayer MoS². Moreover, the partial density of states is also calculated and analyzed.