Covalent Organic Framework‐Based Optoelectronic Memristors: Structural Design, Optoelectronic Modulation and Neuromorphic Applications

Abstract

Covalent organic frameworks (COFs) offer a tunable platform for optoelectronic memristors by coupling light absorption with history‐dependent conductance, yet their potential remains underexplored. This review systematically examines how structural features, including linkage chemistry, donor–acceptor organisation, dimensionality, layer stacking, photochromic groups, redox centres and pore environments, govern the generation and stabilisation of excited, charged, isomeric and ionic states. It then traces the translation of these states into device‐level conductance modulation via molecular switching, photoredox reactions, charge trapping, interfacial photogating and ion or filament motion, with special emphasis on film quality, electrode contacts and semiconductor heterointerfaces. Functional capabilities such as temporal plasticity, bidirectional programming, spectral encoding, adaptive vision, denoising, motion recognition and task‐specific sensing are critically assessed, distinguishing genuine device responses from software simulations and physically integrated arrays. From this analysis, three design rules emerge: charge separation must operate within a reversible kinetic window, the stored state should be identifiable independently of conductance, and framework architecture must align with the device current path. The primary opportunity lies in linking chemically defined state variables to optically addressable conductance, whereas major challenges include incomplete mechanistic validation, limited device statistics, environmental instability and the lack of fully integrated addressable COF arrays. The review concludes with priorities for mechanism‐resolved characterisation, scalable processing and circuit integration.