Ab-Initio and Experimental Study of the Electronic and Optical Properties of Layered 2D Molybdenum Disulphide

Abstract

Molybdenum disulphide (MoS₂) in its two-dimensional (2D) mono- to few layers is applied in numerous photonic applications owing to its wide bandgap. In this work, the electronic and optical properties of monolayer MoS₂ were successfully investigated by ab initio study through density functional theory (DFT) calculation and experimental work. A 2D monolayer MoS₂ model was simulated using CASTEP in the framework of plane-wave pseudopotential. The simulated bandgap is 1.7 eV which is interestingly close to those determined bandgap of MoS₂ prepared through the liquid-phase exfoliation method. This confirmed the successful formation of 2D layered MoS₂ in the proposed fabrication process. The MoS₂ model also predict well the experimentally derived absorption range which has a significant peak at around ~600 nm wavelength ascribed to the excitonic property.