Type-II InSe/MoSe2(WSe2) van der Waals heterostructures: vertical strain and electric field effects

Abstract

Two-dimensional (2D) InSe, a new graphene-like semiconducting material, is gaining significant attention due to its particular optoelectronic characteristics. However, the studies of InSe-based van der Waals heterostructures (vdWHs) are in its initial stages, which limits its applications in future nano-devices. In this work, we utilize first-principles calculations to investigate 2D InSe/MoSe₂(WSe₂) vdWHs considering stacking configurations, vertical strain and electric field effects. The results show that the most stable 2D InSe/MoSe₂(WSe₂) vdWHs possess an intrinsic type-II band alignment. Additionally, the vertical strain not only tunes the band gap but also induces the band alignment transition from type-II to type-I in the vdWHs. Besides, application of external electric field can also transfer the intrinsic type-II band alignment to type-I or type-III. This work predicates the feasibility of 2D InSe/MoSe₂(WSe₂) vdWHs and extends the applications of 2D InSe materials in the field of optoelectronics.