Solar-blind optoelectronic synapses enabled by amorphous Ga2O3/SiC heterostructure

Solar-blind optoelectronic synapses are attractive for front-end neuromorphic processing under deep-ultraviolet illumination, yet Ga2O3-based two-terminal systems remain largely confined to electrically driven memristive switching. Here, we demonstrate a sputtered amorphous Ga2O3/SiC heterostructure for two-terminal solar-blind optoelectronic synaptic operation. Ga2O3 provides solar-blind absorption, while the SiC region serves as the transport/readout channel, enabling separation of optical excitation and electrical conduction. The device exhibits excitatory postsynaptic current, paired-pulse facilitation, tunable short-term-to-long-term memory, and learning–forgetting–relearning behavior under 254 nm pulses. Results indicate that the synaptic behavior is governed by solar-blind absorption in Ga2O3, interfacial charge transfer, and defect-mediated relaxation. This work offers a scalable heterostructure approach for solar-blind neuromorphic optoelectronic devices.