Controllable Band Alignment Transition in InSe-MoS2 Van der Waals Heterostructure

Van der Waals (vdW) heterojunctions with type-II band alignment, in which electrons and holes are localized in distinct layers, play a central role in optoelectronic devices and solar cells. The present study analyzes a type-III band alignment transition in InSe-MoS2 vdW heterostructure, proposed to be controlled via changing interlayer distance or applying perpendicular external electric field. The band position shift of InSe relative to that of MoS2 attributes to a surface polarization mechanism. Changing band offset into type II facilitates possible use and allows greater flexibility for band engineering of InSe-MoS2 heterostructure in optoelectronic and solar energy applications. The present findings provide theoretical guidance to a new approach to improve the optoelectronic properties of vdW heterostructures.