A light-emitting electrochemical artificial synapse with dual output of photoelectric signals

Abstract

Despite recent remarkable progress in multiple synaptic devices, searching for artificial synapses with new functions is still an important task in the construction of artificial neural networks. The parallel output functionality of photoelectric signals in artificial synaptic devices is interesting and desirable as on-chip optoelectronic interconnection technology allows the connections between neurons weighted by current and light. In turn, it provides degrees of freedom and reduces circuit lead density in the design of large-scale neural networks. Hence, for the first time, a light-emitting electrochemical artificial synapse (LEEAS) based on poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene vinylene]/poly (ethylene oxide)/lithium salt blends with dual output of photoelectric signals was developed in this study. The electrochemical redox reaction enables the device to achieve synaptic plasticity in biology and emulate the memory enhancement process, high-pass filtering characteristic, and classical Pavlov’s conditioned reflex experiment. In addition, the transient luminescence intensity of the LEEAS induced by identical electric spikes exhibits a synaptic-like potentiation behavior. Owing to the combination of electroluminescence (EL) and synaptic memory behavior, an LEEAS array exhibits a unique image display and storage functions that can memorize displayed images. The LEEAS proposed in this work enriches the diversity of artificial synapses, promoting the diversified design and development of next-generation optoelectronic hybrid artificial neural networks.