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

Highlights: • Intrinsic monolayer MoS₂ and Sb-doped monolayer MoS₂ are all semiconductors. • The absorption edge of the Sb-doped MoS₂ system shows a slight redshift. • There are two different reflection peaks in both doping systems, and the peaks are much larger than in the intrinsic MoS₂. 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.