First-principles study of antimony-doped monolayer molybdenum disulfide: Electronic structure and optical properties

Abstract

Based on the first principles of density functional theory, the electronic structure and optical properties of intrinsic monolayer molybdenum disulfide (MoS2) and antimony (Sb)-doped monolayer MoS2 have been studied, including the formation energy, band structure, state density, differential-charge density and optical properties that have been calculated. These calculated results indicate that the intrinsic monolayer MoS2, Sb-substituted Mo-doped monolayer MoS2, and Sb-substituted S-doped monolayer MoS2 are all semiconductors with band gaps of 1.68 eV, 1.06 eV, and 1.47 eV, respectively. Thus, doping with Sb can better modify the band structures for MoS2. Moreover, by calculating the differential charge density, it is found that doping with Sb atoms can stimulate more large charge transfers in monolayer MoS2. More importantly, after Sb doping, the absorption of visible and ultraviolet light by MoS2 nanomaterials is enhanced. The absorption edge of the Sb-doped MoS2 system shows a slight redshift. In addition, for the reflectivity of the two doping systems, there are two different reflection peaks in both doping systems, and the peaks are much larger than in the intrinsic MoS2. These theoretical results are expected to provide useful guidelines for the design of photoelectron nanodevices based on monolayer MoS2.