Multifunctional Ultralow-Power-Consumption Artificial Optoelectronic Synapses Based on the Heterojunctions of MoO ₃ /WO ₃ for Neuromorphic Computing and Bionic Visual Systems

Due to the high energy and processing efficiencies, brain-inspired optoelectronic synaptic systems provide a promising solution for next-generation artificial vision computing. However, synapses based on single oxides face the challenge of high-power consumption, which seriously limits their practical application. This study presents multifunctional heterojunction optoelectronic synapses with low power consumption. Layered MoO 3 and photochromic WO 3 films are deposited in turn onto the ITO-covered quartz substrates by using the electron beam evaporation technique, and metal-oxide heterojunction synapses of MoO 3 /WO 3 are fabricated. The synaptic devices exhibit versatile neuromorphic functionalities under both electrical and optical modulation. The heterojunction enables long- and short-term plasticity and achieves an accuracy of up to 92.4% in handwritten digit recognition. Under light stimulation, the device successfully demonstrated basic and advanced synaptic functions. More importantly, the power consumption of the synaptic event is only 67.6 fJ, which is far below those of other similar devices and close to biological synapses. The optoelectronic synapse arrays of 4 × 4 are developed to realize real-time visual perception and memory behaviors. This work provides effective strategies and a scientific foundation for developing next-generation ultralow-power artificial intelligence vision chips.