Tunable electronic and optical properties of InSe/arsenene heterostructure by vertical strain and electric field

Abstract

We construct seven possible stacking orders of InSe/arsenene heterostructures which consists of 23×23×1 InSe and 4×4×1 arsenene supercells, and investigate the electronic and optical properties of the most stable heterostructure based on the first-principles method. It is demonstrated that it has a direct band gap (Eg) of 0.68 eV and a type-II band alignment, which is conducive to the efficient separation of photonic electrons and holes. Vertical strain and applied electric field can regulate significantly the electronic properties. The InSe/arsenene heterostructure changes from type II to type I and then to type II under different electric fields, resulting in different spatial distribution of the lowest energy electron-hole pairs, and the transition from semiconductor to metal also can be observed under stronger electric fields. InSe/arsenene heterostructure exhibits a wide absorption range, and the absorption strength (edge) can be tuned by the interlayer coupling or external electric field.