Low-temperature solution-processed amorphous-Ga2O3 optoelectric synapses for neuromorphic computing

Abstract

Optoelectronic synaptic devices present a promising approach to address the limitations of the von Neumann architecture. In this work, the amorphous gallium oxide (a-Ga2O3) optoelectronic synaptic devices were prepared by using a cost-effective sol–gel technique at a relatively low temperature of 400 °C. The a-Ga₂O₃ devices exhibit an exceptionally wide bandgap and a stable, persistent photoconductive effect, allowing for the effective emulation of short- and long-term plasticity, paired-pulse potentiation, and pulse time-dependent plasticity akin to biological synapses. A digital image recognition method and a clothing image recognition method based on the LeNet-5 neural network model also were developed, achieving recognition rates of 97.8 % and 78 %, respectively. These findings are expected to contribute to the advancement of artificial synaptic devices, neural networks, and computing systems capable of optoelectronic operations.