Ferroelectric Switching Behavior in Two-Dimensional Semiconductor α-In<sub>2</sub>Se<sub>3</sub> for Nonvolatile Memory
Zhengxin Li, Yangyang Chen, Jian Yuan, Wanting Xu, Xiaoqing Yang, Haotian Wang, Chuanbing Cai, Takashi Taniguchi, Kenji Watanabe, Yanfeng Guo, Zhiyong Liu, Wei Ren
Abstract
Ferroelectric memristors, a type of nonvolatile resistive switching memory, have enormous potential in applications, including information storage and neuromorphic computing. The recent focus on two-dimensional (2D) ferroelectrics highlights their significance as a promising platform for the next generation of functional electronic devices. Here, we report ferroelectricity in exfoliated 2D α-In 2 Se 3 flakes through piezoelectric force microscopy and transport measurement. An out-of-plane ferroelectricity is directly characterized by a box-in-box ferroelectric domain pattern. In-plane ferroelectricity is also proved in α-In 2 Se 3 planar ferroelectric devices by the large hysteresis loop, while the out-of-plane ferroelectricity is further observed by the electric field gating effect. Remarkably, this 2D α-In 2 Se 3 -based ferroelectric semiconductor field-effect transistor exhibits a high on/off ratio as well as good cyclability. Additionally, few-layer graphene/α-In 2 Se 3 /few-layer graphene ferroelectric heterojunctions are also fabricated, which showcase the potential of α-In 2 Se 3 for vertical ferroelectric memristors.