LAUSR

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 SnS2/WSe2 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 SnS2/WSe2. As a contrast, corresponding calculations of monolayer (or bilayer) SnS2 and WSe2 were also implemented. It is shown that monolayer SnS2 and WSe2 are direct (1.583 eV) and indirect (1.476 eV) band gap semiconductors, respectively. For hetero-bilayer SnS2/WSe2, 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 SnS2/WSe2 can be realized by implying in-plane compressing/stretching strain and external electric field. Our results are useful complement to experimental studies of SnS2-based (or WSe2-based) hybrid systems and provide a new route to facilitate fabricate optoelectronic devices where controllable bandgap are needed.