Understanding Microscopic Operating Mechanisms of a van der Waals Planar Ferroelectric Memristor

Abstract

Ferroelectric memristors represent a promising new generation of devices that have a wide range of applications in memory, digital information processing, and neuromorphic computing. Recently, van der Waals ferroelectric In2Se3 with unique interlinked out-of-plane and in-plane polarizations has enabled multidirectional resistance switching, providing unprecedented flexibility in planar and vertical device integrations. However, the operating mechanisms of these devices have remained unclear. Here, through the demonstration of van der Waals In2Se3-based planar ferroelectric memristors with the device resistance continuously tunable over three orders of magnitude, and by correlating device resistance states, ferroelectric domain configurations, and surface electric potential, the studies reveal that the resistive switching is controlled by the multidomain formations and the associated energy barriers between domains, as opposed to the commonly assumed Schottky barrier modulations at the metal-ferroelectric interface. The findings reveal new device physics through elucidating the microscopic operating mechanisms of this new generation of devices, and provide a critical guide for future device development and integration efforts.