Tunable Electronic, Optoelectronic, and Photocatalytic Properties of MoS ₂ and GaS Monolayers in the MoS ₂ /GaS Heterostructure

Abstract The electronic structure calculations show that the GaS and MoS 2 monolayer and MoS 2 /GaS hetero‐bilayer systems are semiconducting materials. It is also justified by the density of states. In the hetero‐bilayer system, the band gap is reduced. It causes an increase in the absorption, compared to their monolayers, of incident light in the visible region. This may be because of the charge transfer and the interlayer interaction between these monolayers in the heterostructure form. The calculated higher extinction coefficient causes the fast absorption of light, hence, the increased absorption coefficient. The heterostructure system makes the refractive index and reflection coefficient of GaS and MoS 2 monolayers tuneable. The static reflection coefficient is in the following order GaS < MoS 2 /GaS < MoS 2 . It means that the MoS 2 /GaS heterostructure system can increase the static refractive index of GaS and decrease that of MoS 2 monolayers simultaneously. The calculated band edge positions show that the MoS 2 and GaS monolayers have excellent water oxidation and reduction capability, respectively. These predictions show that the proposed heterostructure may be a potential candidate for nanoelectronics and optoelectronics.