Abstract Two-dimensional (2D) van der Waals heterostructures (vdWHs) have attracted significant attention due to their potential applications in nanoscale electronic devices. Based on the first-principles calculations, we design the SnSe/SnTe and SnSe/SnTe/SnSe vdWHs with dynamical stability and thermal stability and investigate their mechanical and electronic properties. We find that the SnSe/SnTe and SnSe/SnTe/SnSe vdWHs have better flexibility than other 2D vdWHs. The SnSe/SnTe and SnSe/SnTe/SnSe vdWHs show reduced direct bandgap and indirect bandgap, respectively. They can also realize the transition between direct and indirect bandgap, and even exhibit the metallic property under external strains. Furthermore, the SnSe/SnTe and SnSe/SnTe/SnSe vdWHs exhibit stable ferroelectric spontaneous polarizations with small potential barriers. The ferroelectric spontaneous polarization of SnSe/SnTe vdWH increases rapidly as the biaxial tensile strain (

中文翻译：

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SnSe/SnTe范德华异质结构的应变可调铁电性

摘要二维 (2D) 范德华异质结构 (vdWHs) 由于其在纳米电子器件中的潜在应用而引起了广泛关注。基于第一性原理计算，我们设计了具有动态稳定性和热稳定性的 SnSe/SnTe 和 SnSe/SnTe/SnSe vdWH，并研究了它们的机械和电子性能。我们发现 SnSe/SnTe 和 SnSe/SnTe/SnSe vdWH 比其他 2D vdWH 具有更好的灵活性。SnSe/SnTe 和 SnSe/SnTe/SnSe vdWH 分别显示出降低的直接带隙和间接带隙。它们还可以实现直接和间接带隙之间的过渡，甚至在外部应变下表现出金属特性。此外，SnSe/SnTe 和 SnSe/SnTe/SnSe vdWH 表现出稳定的铁电自发极化和小的势垒。