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.

二维范德华异质结构具有出色的电子性能，为未来纳米级电子器件的发展提供了新的平台。利用基于密度泛函理论的第一性原理计算，我们系统地研究了SnS ₂ / WSe ₂异质双层系统的电子性能。我们主要关注平面内双轴应变和外部电场对异质双层SnS ₂ / WSe ₂的能带结构的影响。作为对比，还执行了单层（或双层）SnS ₂和WSe _2的相应计算。显示单层SnS ₂和WSe ₂分别是直接（1.583 eV）和间接（1.476 eV）带隙半导体。对于异质双层SnS ₂ / WSe ₂，在六个被认为独立的堆叠结构中，最稳定的系统表现为II型能带对准，带隙为0.269 eV。此外，可以通过暗示面内压缩/拉伸应变和外部电场来实现异质双层SnS ₂ / WSe _2中的可调带隙。我们的结果是对基于SnS ₂的（或基于WSe ₂的）混合系统进行实验研究的有益补充，并为在需要可控带隙的情况下制造光电器件提供了新途径。