Liu Guogang, Chen Tong, Zhou Guanghui, Xu Zhonghui, Xiao Xianbo
School of Software Engineering, Jiangxi University of Science and Technology, Nanchang 330013, P. R. China.
School of Energy and Mechanical Engineering, Energy Materials Computing Center, Jiangxi University of Science and Technology, Nanchang 330013, P. R. China.
ACS Sens. 2023 Apr 28;8(4):1440-1449. doi: 10.1021/acssensors.2c02365. Epub 2023 Mar 27.
Nonvolatile electrical control is the core of future magnetoelectric nanodevices. In this work, we systematically explore both the electronic structures and transport properties of multiferroic van der Waals (vdW) heterostructures consisting of a ferromagnetic FeI monolayer and a ferroelectric InS monolayer using density functional theory and the nonequilibrium Green's function method. The results reveal that the FeI monolayer can be reversibly switched between semiconducting and half-metallic properties by nonvolatile control of the InS ferroelectric polarization states. Correspondingly, the proof-of-concept two-probe nanodevice based on the FeI/InS vdW heterostructure exhibits a significant valving effect by modulating the ferroelectric switching. Moreover, it is also found that the preference of nitrogen-containing gases such as NH, NO, and NO for adsorption on the surface of FeI/InS vdW heterostructures strongly depends on the polarization direction of the ferroelectric layer. In particular, the FeI/InS heterostructure shows reversible capture behavior for NH. As a result, the FeI/InS vdW heterostructure-based gas sensor demonstrates high selectivity and sensitivity. These findings may open up a new route for the application of multiferroic heterostructures to spintronics, nonvolatile memories, and gas sensors.
非易失性电控制是未来磁电纳米器件的核心。在这项工作中，我们使用密度泛函理论和非平衡格林函数方法，系统地研究了由铁磁FeI单层和铁电InS单层组成的多铁性范德华（vdW）异质结构的电子结构和输运性质。结果表明，通过对InS铁电极化状态的非易失性控制，FeI单层可以在半导体和半金属性质之间可逆切换。相应地，基于FeI/InS vdW异质结构的概念验证双探针纳米器件通过调制铁电开关表现出显著的阀效应。此外，还发现含氮气体如NH、NO和NO在FeI/InS vdW异质结构表面的吸附偏好强烈依赖于铁电层的极化方向。特别是，FeI/InS异质结构对NH表现出可逆的捕获行为。因此，基于FeI/InS vdW异质结构的气体传感器具有高选择性和高灵敏度。这些发现可能为多铁性异质结构在自旋电子学、非易失性存储器和气体传感器中的应用开辟一条新途径。
