CsPbBr3/graphene nanowall artificial optoelectronic synapses for controllable perceptual learning

作者：Runze Li, Yibo Dong, Fengsong Qian, Yiyang Xie, Xi Chen, Qiming Zhang, Zengji Yue, Miṅ Gu · 发表于：PhotoniX · 年份：2023 · DOI：10.1186/s43074-023-00082-8 · 被引用次数：58 · 研究领域：Advanced Memory and Neural Computing、Photoreceptor and optogenetics research、Neural Networks and Reservoir Computing

Abstract The rapid development of neuromorphic computing has stimulated extensive research interest in artificial synapses. Optoelectronic artificial synapses using laser beams as stimulus signals have the advantages of broadband, fast response, and low crosstalk. However, the optoelectronic synapses usually exhibit short memory duration due to the low lifetime of the photo-generated carriers. It greatly limits the mimicking of human perceptual learning, which is a common phenomenon in sensory interactions with the environment and practices of specific sensory tasks. Herein, a heterostructure optoelectronic synapse based on graphene nanowalls and CsPbBr 3 quantum dots was fabricated. The graphene/CsPbBr 3 heterojunction and the natural middle energy band in graphene nanowalls extend the carrier lifetime. Therefore, a long half-life period of photocurrent decay - 35.59 s has been achieved. Moreover, the long-term optoelectronic response can be controlled by the adjustment of numbers, powers, wavelengths, and frequencies of the laser pulses. Next, an artificial neural network consisting of a 28 × 28 synaptic array was established. It can be used to mimic a typical characteristic of human perceptual learning that the ability of sensory systems is enhanced through a learning experience. The learning behavior of image recognition can be tuned based on the photocurrent response control. The accuracy of image recognition keeps above 80% even under a low-frequency learning process. W...