Modulation of band structure and optical properties of InSe/ZnSe vertical van der Waals heterojunction under external electric field and Biaxial strain

This article comprehensively investigates the electronic structure and optical properties of InSe/ZnSe vertical van der Waals heterostructures (vdWHs) under biaxial strain modulation and external electric field by using the first-principles calculations based on density functional theory (DFT). Notably, we find the tunability of band gap and electronic performance under biaxial strain and external electric field, as well as the transition from semiconductor to metal. Compared with the single monolayer, InSe/ZnSe vdWHs enhances the light absorption ability, the tensile strain causes the redshift of the optical absorption spectrum of the heterostructure; while the compressive strain enhances the light absorption ability of the InSe/ZnSe vdWHs e in the ultraviolet light region, the external electric field enhances the light absorption ability of InSe/ZnSe vdWHs in the visible light region. The phonon spectrum and elastic constants confirm the dynamic and mechanical stability of InSe/ZnSe vdWHs, proving that it not only exists in theory, but also has the hope of being manufactured in the laboratory. This study provides a theoretical basis for the potential applications of InSe/ZnSe vdWHs in optoelectronic devices and strain-sensitive technologies.