In the scope of two-dimensional (2D) material study, blue phosphorus (BP) is a new graphene-like layered structure that has been successfully synthesized in the experiment after it was theoretically proved to be thermostable. These 2D structured functional materials have great potential in the next-generation nanoscale electronic devices for their unique features. Here, we composite BP and monolayer WX2 (X = S/Se/Te) based on van der Waals force (vdW) interaction to obtain well-defined type-II band alignment heterostructures. A systematic theoretic study was conducted to explore the interlayer coupling effects and the bands’ re-alignment of the BP–WX2 heterostructure after the strain was applied. Nowadays, many researches have proved that 2D materials can be used to degrade pollutants or used as a potential photovoltaic cell material to obtain high performance. We here twist BP and WX2 (X = S/Se/Te) into different angles to lay a theoretical framework on the band alignment and carriers’ separation. It reveals that the electronic properties of freestanding BP and WX2 can be roughly preserved in the corresponding heterostructures. Upon applying strain, band alignment exhibits significant adjustability through varying external strain. The heterostructures are type-II in a certain strain range, within which the carriers can be effectively separated spatially. These heterostructures undergo a transition from semiconductor to metal when a certain strain is imposed. This work not only provides a deep insight into the construction of heterostructures, but presents a new possibility for strain engineering that is both flexible and feasible and can be used for diverse applications.

中文翻译：

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蓝磷-WX2 (X = S/Se/Te) 垂直异质结构的应变可调带对齐：来自第一性原理研究

在二维（2D）材料研究范围内，蓝磷（BP）是一种新的类石墨烯层状结构，在理论上证明其具有热稳定性后，在实验中成功合成。这些二维结构功能材料因其独特的特性在下一代纳米级电子设备中具有巨大的潜力。在这里，我们基于范德华力 (vdW) 相互作用复合 BP 和单层 WX2 (X = S/Se/Te)，以获得明确定义的 II 型能带排列异质结构。进行了系统的理论研究，以探索施加应变后 BP-WX2 异质结构的层间耦合效应和能带重新排列。如今，许多研究证明，二维材料可用于降解污染物或用作潜在的光伏电池材料以获得高性能。我们在这里将 BP 和 WX2 (X = S/Se/Te) 扭曲成不同的角度，为带对齐和载流子分离奠定理论框架。这表明独立的 BP 和 WX2 的电子特性可以大致保留在相应的异质结构中。在施加应变时，带对齐通过改变外部应变表现出显着的可调节性。异质结构在一定应变范围内为II型，在该范围内载流子可以有效地在空间上分离。当施加一定的应变时，这些异质结构经历从半导体到金属的转变。这项工作不仅深入了解异质结构的构建，