Two-dimensional Janus Polarization Functioned by Mechanical Force.

Two-dimensional (2D) polarization materials have emerged as promising candidates for meeting the demands of device miniaturization, attributed to their unique electronic configurations and transport characteristics. Although the existing inherent and sliding mechanisms have been increasingly investigated in recent years, strategies for inducing 2D polarization with innovative mechanisms remain rare. In this study, we introduce a novel 2D Janus state by modulating the puckered structure. Combining scanning probe microscopy, transmission electron microscopy, and density functional theory calculations, we realized force-triggered out-of-plane and in-plane dipoles with distorted smaller warping in GeSe. The Janus state is preserved after removing the external mechanical perturbation, which could be switched by modulating the sliding direction. Our work offers a versatile method to break the space inversion symmetry in a 2D system to trigger polarization in the atomic scale, which may open an innovative insight into configuring novel 2D polarization materials. This article is protected by copyright. All rights reserved.