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

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.