Competing Ferroelectric Polarization and Defect Migration Induced Resistive Switching in β′-In2Se3

Layered β'-In₂Se₃ has garnered significant attention due to its intriguing multiferroic properties. Until now, most studies have focused on a material-level understanding, with limited exploration of device-level properties. This work systematically investigates the in-plane resistive switching behavior of β'-In₂Se₃. Besides resistive switching resulting from ferroelectric polarization reversal, the critical role of defect migration is unveiled in determining the overall electrical characteristics of β'-In₂Se₃ devices. Specifically, we elucidate the contribution of electric-field-induced Se vacancy migration to resistive switching through time-dependent current evolution, in situ electric force microscopy, and density functional theory calculations. By considering the interplay between free carriers, bound charges, and mobile defects, a comprehensive physical picture of the complex resistive switching behavior of β'-In₂Se₃ devices is established. This work provides crucial insights into understanding and manipulating the resistive switching behavior of 2D vdW ferroelectric devices.