Electroforming‐Free Artificial Synapses Based on Proton Conduction in α‐MoO3 Films

Abstract Artificial synapses based on oxides are essential for constructing brain‐inspired computation systems, due to their dynamically tunable defect concentrations. However, defects in the pristine state of most oxides are usually not sufficient, unavoidably resulting in an irreversible electroforming process, which usually produces undesired side effects, such as device variations and failures. Electroforming‐free memristive devices are realized with single‐phase α‐MoO3 films. By introducing protons into α‐MoO3 through annealing in H2/Ar atmosphere, the destructive electroforming process is avoided, which results in uniform switching behavior with high yield and minimal spatial/temporal variations. In addition, synaptic functions such as short‐term memory and long‐term memory are successfully emulated with the device, and the image memorizing function is embodied by memorizing the letter “Y” out of three letters “X, Y, Z” in a 5 × 5 array.