Ga₂O₃-Based Optoelectronic Synapse With Piezo/Photo-Gated Modulation for Multimodal Perception

Ga2O3 leverage high deep-ultraviolet (DUV) responsivity and persistent photoconductivity (PPC) to enable low-power synaptic devices. However, limited PPC relaxation controllability in existing Ga₂O₃ synapses restricts tunable plasticity. This work demonstrates a piezo/photo-gated modulated Ga₂O₃/ZnO synaptic device for multimodal perception. The device exhibits reconfigurable synaptic plasticity—including paired-pulse facilitation, short-to-long-term plasticity transition, and dynamic weight modulation — under 254 nm light pulses. Crucially, compressive strain (−0.57%) enhances synaptic weight change by 22% (from 1076.3% to 1310.2%), attributed to strain-induced band bending at the heterojunction interface that regulates carrier separation and oxygen vacancy recombination. This strain-modulated behavior enables intelligent health care to the human body, where electrocardiogram pattern recognition achieves 83.5% accuracy using a single-layer neural network. This study establishes a viable approach for developing functionally tunable photoelectric synapses with co-integrated sensing-memory-processing capabilities for artificial tactile-perception systems.