Pyrazole‐Azobenzene Based Covalent Organic Framework Optoelectronic Synapse Device for Mixed‐Color Information Recognition

ABSTRACT Organic optoelectronic synapse devices have attracted significant interest in the construction of artificial visual systems for visual information recognition and data processing. These devices can facilitate both information reception and processing within a single unit, thereby enabling bio‐inspired, system‐level efficient computation. However, conventional photosensitive elements typically respond only to the intensity of incident light and lack the capability to distinguish between specific wavelengths, which significantly restricts their application in mixed‐color information recognition. In this study, we report the development of an optoelectronic synapse device based on a covalent organic framework containing pyrazole azobenzene(COF‐TAMP). The pyrazole azobenzene moieties in COF‐TAMP undergo stepwise cis‐trans photoisomerization when exposed to light pulses ranging from 405 to 630 nm, enabling at least 20 distinct conductance states across 11 different wavelengths within the visible spectrum. Furthermore, the device exhibits remarkable optoelectronic synaptic behaviours, as demonstrated in paired‐pulse facilitation and depression experiments. Arrays of these multiwavelength‐responsive optoelectronic synapse devices offer significant potential for applications in artificial visual systems and are poised to address color distortions in modern images, thereby providing a novel approach for mixed‐color information perception.