Polarization-Modulated Solar-Blind Optoelectronic Synapse Based on Anisotropic β-Ga2O3 Crystal for Logic Operations and Motion Perception

Photoelectronic synapses exhibit remarkable potential in neuromorphic systems due to their unique multimodal sensing and brain-like information processing capabilities. However, their complex device architectures and limited functionalities remain critical bottlenecks. In this study, we innovatively developed a polarization-sensitive optoelectronic synaptic device based on β-Ga₂O₃ single crystals. Through systematic characterization, we revealed the synergistic advantages of the (100)-oriented β-Ga₂O₃ crystal in terms of persistent photoconductivity (PPC) effects and anisotropy. The developed solar-blind polarization-sensitive synaptic device demonstrated polarization-dependent postsynaptic current (EPSC), short-term memory (STM), and advanced learning–forgetting–relearning behavior. Notably, we achieved in situ switching between the OR/AND and NOR/NAND logic gates through polarization modulation. For neuromorphic computing applications, the device exhibited superior synaptic weight modulation capabilities, enabling the control of conductance states via a photoenhancement/electrosuppression mechanism and achieving a 77.6% classification accuracy on a Fashion MNIST data set. Notably, we realized a multimodal signal fusion function, achieving a 98.2% real-time recognition accuracy for missile motion perception. This work fundamentally advances the development and application of neuromorphic optoelectronics by realizing synaptic functions through polarization control.