Structural and Electronic Properties of Heterostructures Composed of Antimonene and Monolayer MoS.

Antimonene is found to be a promising material for two-dimensional optoelectronic equipment due to its broad band gap and high carrier mobility. The van der Waals heterostructure, as a unique structural unit for the study of photoelectric properties, has attracted great attention. By using ab initio density functional theory with van der Waals corrections, we theoretically investigated the structural and electronic properties of the heterostructures composed of antimonene and monolayer MoS. Our results revealed that the Sb/MoS hetero-bilayer is an indirect semiconductor with type-II band alignment, which implies the spatial separation of photogenerated electron-hole pairs. Due to the weak van der Waals interlayer interactions between the adjacent sheets of the hetero-bilayer systems, the band structures of isolated antimonene and monolayer MoS are preserved. In addition, a tunable band gap in Sb/MoS hetero-bilayer can be realized by applying in-plane biaxial compressing/stretching. When antimonene and monolayer MoS are stacked into superlattices, the indirect semiconductors turn into direct semiconductors with the decreased band gaps. Our results show that the antimonene-based hybrid structures are good candidate structures for photovoltaic devices.