Constructing van der Waals heterostructures can be considered as an effective strategy for generating new physical phenomena that merit for high-efficiency nanodevices. Here, we construct the ${\mathrm{PbI}}_2$/${\mathrm{SnSe}}_2$ heterostructure using first-principles calculations and explore its electronic structure and optical performance as well as the effects of electric fields. The ${\mathrm{PbI}}_2$/${\mathrm{SnSe}}_2$ heterostructure owns an indirect band gap and exhibits type-I band alignment, making it promising candidate for light emission applications. Furthermore, the optical absorption of the ${\mathrm{PbI}}_2$/${\mathrm{SnSe}}_2$ heterostructure in both the visible light and ultra-violet regions is enhanced as compared with that of the ${\mathrm{PbI}}_2$ and ${\mathrm{SnSe}}_2$ monolayers. Furthermore, in the ${\mathrm{PbI}}_2$/${\mathrm{SnSe}}_2$ heterostructure, the electric fields can convert the type-I to type-II band alignment and tune the transition from semiconductor to metal. Our results provide useful guidance for practical application in high-efficiency nanodevices.

构建范德华异质结构可以被视为一种有效的策略，可产生对高效纳米器件有益的新物理现象。在这里，我们构造${\mathrm{铅}}_2$/${\mathrm{硒}}_2$使用第一性原理计算异质结构，并探索其电子结构和光学性能以及电场的影响。的${\mathrm{铅}}_2$/${\mathrm{硒}}_2$异质结构具有间接带隙，并表现出I型能带排列，使其成为有希望的发光应用候选者。此外，光的吸收${\mathrm{铅}}_2$/${\mathrm{硒}}_2$ 与可见光区和紫外线区相比，可见光区和紫外线区的异质结构都得到了增强。 ${\mathrm{铅}}_2$ 和 ${\mathrm{硒}}_2$单层。此外，在${\mathrm{铅}}_2$/${\mathrm{硒}}_2$异质结构，电场可以将I型转变为II型能带排列，并调节从半导体到金属的跃迁。我们的结果为在高效纳米器件中的实际应用提供了有用的指导。