First-principles calculation of influence of biaxial strain on the electronic structure and optical properties of ZnSe/InSe van der waals heterojunction

The electronic properties of the InSe monolayer supported on the surface of ZnSe monolayer were studied by the DFT study. In this paper, a first-principles approach was used to study the regulation of the electronic structure and optical properties of InSe/ZnSe heterojunctions by biaxial strain. The results show that the forbidden band width of the InSe/ZnSe heterojunction is 1.040 eV. Due to the built-in electric field generated in the heterojunction system, the recombination rate of photogenerated carriers is reduced, and the light absorption band edge of the heterojunction is extended to the visible light region. After straining the heterojunction, its forbidden band width is reduced. Compared with the unstrained system, the strain has a stronger hindering effect on photogenerated electron carriers, and its photocatalytic ability is greatly improved. The above results show that the construction of the InSe/ZnSe heterojunction and the biaxial strain can significantly control the electronic structure and optical properties of the heterojunction, making it suitable for applications in the fields of narrow band gap and infrared and visible light semiconductor devices, such as photocatalytic materials.