Retina‐Like Chlorophyll Heterojunction‐Based Optoelectronic Memristor with All‐Optically Modulated Synaptic Plasticity Enabling Neuromorphic Edge Detection

• Published in: Advanced functional materials Vol. 34; no. 51
• Main Authors: Jiang, Jian, Shan, Xuanyu, Xu, Jiaqi, Sun, Yuting, Xiang, Tian‐Fu, Li, Aijun, Sasaki, Shin‐ichi, Tamiaki, Hitoshi, Wang, Zhongqiang, Wang, Xiao‐Feng
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.12.2024
• Subjects: all‐optically modulated synaptic plasticity; Chl heterojunction; Chlorophyll; Deionization; Edge detection; Heterojunctions; Light modulation; Memristors; Optoelectronic devices; optoelectronic memristor; Zinc oxide; Zinc oxides
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.202409677

Optoelectronic memristors, which possess the potential capacities of in‐sensor computing, promote the development of highly efficient neuromorphic vision. In this work, a novel optoelectronic memristor based on chlorophyll (Chl) heterojunction is proposed, which consists of two types of Chl derivatives (zinc methyl 3‐devinyl‐3‐hydroxymethyl‐pyropheophorbide‐a and methyl 131‐deoxo‐131‐dicyanomethylene‐pyropheophorbide‐a). Chl heterojunction improves the optoelectronic performance of the device due to its ability to efficiently separate photogenerated electron‐hole pairs. The device exhibits the synaptic potentiation and inhibition behaviors under light stimulations of 430 and 730 nm, respectively, thus demonstrating the all‐optically modulated synaptic plasticity. The switching mechanism can be attributed to the photo‐ionization/deionization of oxygen vacancies at the zinc oxide (ZnO)/Chl interface. In addition, the image pre‐processing functions of contrast enhancement and noise reduction are implemented in a memristive array. In particular, the edge detection function has been implemented by utilizing reversible optical modulation, which highlights the object outline. The optoelectronic memristor based on the Chl heterojunction proposed here provides a promising foundation for advancing neuromorphic vision. An all‐optically modulated optoelectronic memristor is designed based on a heterojunction consisting of two types of chlorophyll derivatives for the first time, mimicking the biological visual functions, especially the edge detection function of retinal bipolar cells, through the interaction between the chlorophyll heterojunctions and ZnO under illumination of different optical wavelengths.