Tuning electronic and optical properties of two–dimensional vertical van der waals arsenene/SnS2 heterostructure by strain and electric field

[Display omitted] •We designed a type-II arsenene/SnS2 vdWH with the band gap of 0.870 eV.•This vdWH has excellent optical absorption from visible to ultraviolet region.•Both strain and electric field can easily tune its electronic and optical properties. The structure and electronic properties of two-dimensional vertical van der Waals arsenene/SnS2 heterostructure are investigated based on the first-principles calculations. The results show that the arsenene/SnS2 bilayer forms a type-II heterostructure with the indirect band gap of 0.870 eV, which is conducive to separating the photogenerated electron-hole pairs. Importantly, the electronic properties of the arsenene/SnS2 heterostructure can be effectively adjusted by applying an external electric field and biaxial strain. Both compressive and tensile strains can decrease the band gap of the arsenene/SnS2 heterostructure, while compressive strain reduces the band gap faster, and the band alignment will have a transition from type-II to type-I when the tensile strain increases to 8%. The band gap of the arsenene/SnS2 heterostructure changes linearly under the external electric field from -1.0 to 1.0 V/Å, while the type-II property is robust in the arsenene/SnS2 heterostructure, not changed by the electric field we consider. Compared to the isolated arsenene and SnS2 monolayers, the arsenene/SnS2 heterostructure has the enhanced optical abaorption from visible to ultraviolet region, especially possessing the absorption peak up to 35.1% in the ultraviolet. Interestingly, there exhibits red shift under tensile strain or negative electric field, and blue shift under compressive strain or positive electric field. Our proposed arsenene/SnS2 heterostructure has great potential applications in electronic and optoelectronic devices.