Optoelectronic properties of two-dimensional InN/WGe2As4 heterostructure with a robust type-II band alignment

Abstract

Two-dimensional van der Waals (vdW) heterostructures show great potential for use in electronic and optoelectronic devices due to their exceptional performance. The diversity of lattice stacking way endows 2D vdW heterostructures with superior tunability of electronic properties. This study systematically investigates the structural, mechanical, and optoelectronic properties of InN/WGe₂As₄ heterostructure based on first-principles calculations. Electronic structure calculations reveal that the InN/WGe₂As₄ heterostructure is a type-II semiconductor with an indirect bandgap of 0.51 eV. The optical absorption peaks in the ultraviolet region of the InN/WGe₂As₄ heterostructure are significantly stronger than those of InN and WGe₂As₄ monolayers. Furthermore, both biaxial tensile strain and decreasing interlayer distance could effectively decrease the bandgap and therefore lead to a red shift of optical absorption. In particular, the InN/WGe₂As₄ heterostructure exhibits a robust type-II band arrangement, which remains stable under the influence of biaxial strain and varying interlayer distance. The findings offer a route to achieve the robust type-II band arrangement heterostructure, which is helpful for the implementation of optoelectronic nanodevices with stable characteristics.