基于二维JanusGeS双层铁电隧道结的电子输运

Electron Transport in Ferroelectric Tunnel Junctions Based on Two-Dimensional Janus GeS Bilayers

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JanusGeS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 firstprinciples 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 GeSbilayer-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.