Photoelectric-Modulated Artificial Synapse Based on Ga 2 O 3 -Based Memristor for Neuromorphic Computing

The Ga2O3-based memristors, fabricated via electron beam evaporation (EBE), exhibit both volatile and nonvolatile resistive switching behaviors. The nonvolatile Ga2O3-based memristors exhibit remarkable resistive switching properties, featuring outstanding cyclic stability, a substantial switching window (>100), and notably low SET/RESET voltages. The observed dual switching modes are attributed to filamentary conduction driven by metallic Cu filaments assisted by oxygen vacancies. The studied Ga2O3-based devices demonstrate both electrically and optically tunable synaptic functionalities, including paired-pulse facilitation (PPF), spike-rate-dependent plasticity (SRDP), spike-timing-dependent plasticity (STDP), potentiation and depression behaviors, as well as light-induced memory characteristics and learning-forgetting capabilities. Intriguingly, high recognition precision of 89.14% on Fashion-MNIST and 97.84% on modified National Institute of Standards and Technology database (MNIST) indicates that wide bandgap semiconductor Ga2O3-based memristors hold immense potential for advancing future neuromorphic computing.