Lithium incorporation enhanced resistive switching behaviors in lithium lanthanum titanium oxide-based heterostructure

Abstract

• Self-rectifying resistive switching device based on lithium lanthanum titanium oxide. • The simplified device has a high rectification ratio and on/off ratio. • Schottky barrier assisted model explains the electronic bipolar resistive switching. • Li + migration accelerates electron injection and enhances the performance of the device. Resistive switching devices with a high self-rectifying ratio are important for achieving the crossbar memristor array that overcomes the sneak current issue. Herein, we demonstrate a single amorphous lithium lanthanum titanium oxide (LLTO) layer based Pt/LLTO/Pt device possessing a self-rectifying ratio higher than 1 × 10 4 that is comparable to the reported devices with complicated multi-layer stacking structures. Moreover, the device shows forming-free and highly uniform bipolar resistive switching (BRS) characteristic that facilitates the potential applications. The trap-controlled and trap-free space charge limited conductions are demonstrated to dominate the high and low resistance states of the device, respectively. The fast migration of lithium ions under external voltage accelerates the electron injection across the Pt/LLTO interface and also the space charge accumulation in the LLTO layer, and as a result, the high performance of the Pt/LLTO/Pt device was achieved. As demonstrated Pt/LLTO/Pt device sheds a light on the potential applications of the lithium ionic conductors in self-rectifying resistive switching devices.