Controllable and Cost‐Efficient Three‐Terminal GaN Nano‐Synapse for Brain‐Inspired Computing

Although the development of highly controllable and low‐cost three‐terminal synaptic nano‐devices is essential for advancing neuromorphic electronics, achieving precise alignment of single nanowire and stable electrical gating still remains severely challenging. Here, we propose and demonstrate a three‐terminal artificial synaptic nano‐device based on the GaN nanowire successfully, enabled by a dielectrophoretic‐assisted assembly strategy that ensures controllable nanowire placement. Benefiting from this cost‐efficient method and with an engineered gate‐coupled interface, the nano‐device exhibits robust and gate‐tunable synaptic plasticity, including short‐/long‐term memory transition, paired‐pulse facilitation, and spike‐timing‐dependent plasticity. By modulating optical spike parameters and gate voltages, the key cognitive behaviors such as learning–forgetting–relearning are effectively emulated, with negative gating significantly accelerating memory reinforcement. They are mainly attributed to the gate‐regulated optoelectronic mechanisms, particularly carrier modulation and oxygen‐vacancy‐induced persistent photoconductivity. Thanks to the excellent regulatory capability of electrical gating, the postsynaptic current of nano‐device can be enhanced over 1,000%. Furthermore, the recognition accuracy can surpass 95% accuracy by gating modulation when integrated into a spiking neural network. This work highlights the promise of three‐terminal nano‐synapses as effective and cost‐efficient building blocks for next‐generation neuromorphic systems.