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

Abstract

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.