Characteristic Resistive Switching of Rare-Earth Oxyhydrides by Hydride Ion Insertion and Extraction

Abstract

Resistive switching induced by ion migration is promising for applications such as random-access memory (ReRAM) and neuromorphic transistors. Hydride ions (H-) are an interesting candidate as the migration ion for resistive switching devices because they have fast diffusion in several compounds at room temperature and doping/dedoping can be used effectively to achieve significant changes in the electronic conductivity. Here, we report reversible resistive switching characteristics in rare-earth oxyhydrides (REHxO(3-x)/2) induced by field insertion/extraction of H-. The current-voltage measurements revealed that the resistive switching response, hysteresis, and switching voltage vary greatly with the H-/O2- ratio in the films. We fabricated a ReRAM device using Ti/YH1.3O0.85/MoOx structure and confirmed the bipolar-type operation with the resistance switching ratio of 1 order of magnitude over 1000 cycles. The composition gradient of H-/O2- in YHxO(3-x)/2 films, in addition to the hydrogen-absorbing ability of the top electrode, is essential for effective device operation. Our findings show that hydride-conducting solid-state electrolytes are suitable for resistive switching device development.