The effect of biaxial strain on the electronic structures and optical properties of GaS/SSnSe heterojunction: A first-principles calculations

Due to their tunable electronic structures and superior optical properties, vertically stacked heterojunctions have received considerable attention. In this paper, the electronic structure, charge transfer, and optical properties of the GaS/SSnSe heterojunction are investigated by first-principles calculations. According to our findings, the GaS/SSnSe heterojunction is a semiconductor with an indirect band gap and a Type-I band alignment. The band alignment of the heterojunction can be linearly tuned by the biaxial strain, which induces a semiconductor-to-metal transition. Moreover, the absorption coefficient of the heterojunction becomes higher and the absorption spectrum appears blue-shifted compared to each monolayer material. The above findings provide a theoretical support for the application of the heterojunction in ultraviolet light detection and tunable devices fields.