Tunable electronic properties of SnS2/WSe2 hetero-structure: A frist principle study

Abstract

The two-dimensional van der Waals hetero-structures have excellent electronic properties, which provide a new platform for the development of nanoscale electronic devices in the future. Utilizing the first principle calculation based on density functional theory, we systematically study the electronic properties of SnS 2 /WSe 2 hetero-bilayer systems. We mainly focused on the effect of the in-plane biaxial strain and external electric field on the energy band structures of hetero-bilayer SnS 2 /WSe 2 . As a contrast, corresponding calculations of monolayer (or bilayer) SnS 2 and WSe 2 were also implemented. It is shown that monolayer SnS 2 and WSe 2 are direct (1.583 eV) and indirect (1.476 eV) band gap semiconductors, respectively. For hetero-bilayer SnS 2 /WSe 2 , among six considered independent stacking structures, the most stable system is manifested as type-II band alignment with a bandgap of 0.269 eV. Moreover, a tunable band gap in hetero-bilayer SnS 2 /WSe 2 can be realized by implying in-plane compressing/stretching strain and external electric field. Our results are useful complement to experimental studies of SnS 2 -based (or WSe 2 -based) hybrid systems and provide a new route to facilitate fabricate optoelectronic devices where controllable bandgap are needed. • Structural and electrical properties of SnS 2 /WSe 2 hetero-bilayers are investigated using DFT-D2 and HSE06 functionals with GGA approximation. • The SnS 2 /WSe 2 hetero-bilayer is an indirect semiconductor with type-II band alignment. • Band gaps of SnS 2 /WSe 2 hetero-bilayers could be modulated by in-plane biaxial compressing/stretching and vertical electric field. • Interlayer interactions of SnS 2 /WSe 2 hetero-bilayers could induce the type–II–to-type-I band alignment transition and semiconductor-to-metal transition.