二维范德华 Janus 材料两侧为不同原子，使得其具有内禀的结构不对称性和面外极化。一 类新型的二维 Janus 材料 GeS 被发现可用于制备低能耗、高响应速度的铁电隧道结。基于第一性 原理计算，我们发现 Janus GeS 双层有三种堆叠模式，它们的横向滑动和垂直位移都可以调节隧 道结中的电子输运。此外，基于 GeGe 接触的 GeS 双层的铁电隧道结表现出最高的开/关比。我 们的研究将滑移铁电的概念扩展到一类新型的二维范德华 Janus 材料，并揭示了这些材料在实际 器件中可能的电阻开关机制。我们的工作为基于二维范德华 Janus 材料的低能耗、快速开关纳米 器件的设计提供了理论指导。 

The two-dimensional van der Waals (2D vdW) Janus materials have different atomic species on both sides to ensure their structural asymmetry and inherent out-of-plane polarizations. A novel 2D vdW Janus material, GeS, was found to develop ferroelectric tunnel junctions (FTJs) with low energy consumption and high response speed. Based on our first-principles calculations, it is found that the Janus GeS bilayers own three stacking modes, and their lateral sliding and vertical displacement can both modulate the electron transport in GeS bilayer-based tunnel junctions. In addition, the FTJ based on GeGe-contacting GeS bilayer exhibits the highest on/off ratio. Our study expands the concept of sliding ferroelectricity to a new class of 2D vdW Janus materials and reveals the possible resistance switching mechanism of these materials in real devices. Furthermore, it provides theoretical guidance for the design of low-energy-consumption and fast-switching nanodevices based on 2D vdW Janus materials.