Artificial optoelectronic synapses based on Ga 2 O 3 metal–semiconductor–metal solar‐blind ultraviolet photodetectors with asymmetric electrodes for neuromorphic computing

Abstract Research on optoelectronic synapses that can integrate both detection and processing functions is essential for the development of efficient neuromorphic computing. Here, we experimentally demonstrated an Ga 2 O 3 ‐based metal–semiconductor–metal (MSM) solar‐blind ultraviolet (UV) photodetector (PD) with asymmetric interdigital electrodes. The Ga 2 O 3 PD exhibits a responsivity of 732 A/W under a forward bias of 6 V. The tunable conductance properties of PDs provide a novel approach to synaptic performance. The proposed PDs as artificial synapse realized several essential synaptic function, including excitatory postsynaptic current, paired‐pulse facilitation, long‐term potentiation, the transition from short‐term memory to long‐term memory, and learning experience behaviors successfully. At a reverse bias, an ultra‐low energy consumption of 140 fJ was achieved. In addition, the optoelectronic synapses demonstrated a recognition accuracy of over 95% in the MNIST handwritten number recognition task. These results suggest that Ga 2 O 3 MSM solar‐blind UV PDs have high potential for efficient optoelectronic neuromorphic computing applications.