中国科学院大学黄辉团队报道了反斯托克斯光致发光实现的有机全光子人工突触。相关研究成果发表在2023年5月11日出版的《美国化学会杂志》。

所有光子突触器件具有可见信号和高时空分辨率的优点，有望打破冯·诺依曼瓶颈。尽管有机突触在易于分子调制和较低能耗方面优于无机突触，但有机全光子人工突触从未被报道过。

该文中，在具有反斯托克斯光致发光的有机半导体（3,6-二甲基-9H-咔唑-9-基）（噻吩-2-基）甲酮（S₂OC）中，前所未有地观察到了所有光子突触特性。令人印象深刻的是，来自更高激发态（S3）的荧光强度表现出突触性能，其通过由系统间交叉、三重态-三重态湮灭和能量转移组成的通道随着照射时间不断增加。更重要的是，建立了分子结构和突触性能之间的关系。基于突触的光塑性特性，在所有光子突触阵列中实现了非接触的多级抗反转录和成像识别。

该项工作为调节有机突触的分子结构提供了一种通用的策略，为有机半导体在人工智能中的应用铺平了道路。

附：英文原文

Title: Organic All-Photonic Artificial Synapses Enabled by Anti-Stokes Photoluminescence

Author: Hao Chen, Yuqi Hou, Yuhao Shi, Yincheng Zhang, Song Wang, Qian Peng, Hui Huang

Issue&Volume: May 11, 2023

Abstract: All-photonic synaptic devices with the merits of visible signals and high spatiotemporal resolution are promising to break the Von Neumann bottleneck. Although organic synapses outperform their inorganic counterpart for easy molecular modulation and lower energy consumption, the organic all-photonic artificial synapse has never been reported. Here, all-photonic synaptic characteristics were unprecedentedly observed in an organic semiconductor, (3,6-dimethyl-9H-carbazol-9-yl)(thiophen-2-yl) methanone (S2OC), with anti-Stokes photoluminescence. Impressively, the intensity of fluorescence from the higher excited state (S3) exhibited synaptic performance, which constantly increased with irradiation time through a channel composed of intersystem crossing, triplet–triplet annihilation, and energy transfer. More importantly, the relationship between the molecular structure and synaptic performance was established. Based on the synaptic photoplasticity property, noncontacted multilevel anticounterfeiting and imaging recognition were realized in all-photonic synapse arrays. This work provides a universal strategy for tuning the performances of organic synapses upon regulating the molecular structures, which paves the way for the application of organic semiconductors in artificial intelligence.

DOI: 10.1021/jacs.2c13471

Source: https://pubs.acs.org/doi/10.1021/jacs.2c13471