A comprehensive study on electronic properties of monolayer MOS2 with spin-orbit coupling

Monolayer Molybdenum disulfide (ML-MoS2) has emerged as a promising two-dimensional (2D) material with unique electronic, optical and mechanical properties. In this paper, with the aid of first-principles calculations, we explain the optimization of the structural and computational parameters and discuss the electrical properties of ML-MoS2. The electronic properties were studied comparatively with and without considering the spin-orbit coupling (SOC) effect that shows, ML-MoS2 has a direct bandgap. A decrease in bandgap energy by 100 meV and a k-valley splitting of 100 mV were observed with the inclusion of SOC. The electronic properties were further analyzed using fat band structures and projected density of states (PDOS), which depict the predominant contribution of Mo d(x)(-y)(2)(2), d(xy) and Mo d(z)(2) orbital to the valence band maximum (VBM) and conduction band minimum (CBM), respectively. Strain-induced bandgap variation was also observed due to the deformation of the crystal structures by shifting and splitting of the energy levels.