A Flexible 2D Covalent Organic Framework Film for Near‐Infrared Visual Adaptation

2D covalent organic frameworks (2D-COFs) have the potential to be employed as photoelectric active layers due to high crystallinity, structural tunability, and their graphene-like 2D layered features. However, photosensors based on 2D-COFs with near-infrared (NIR) visual adaptation and flexibility remain challenges in this field. In this study, a donor-acceptor 2D-COF film is synthesized via a liquid-liquid interfacial polymerization reaction, exhibiting flexibility and broad-spectrum light absorption properties even spanning NIR. Moreover, the as-prepared visual bionic devices demonstrate photonic adaptive behavior with excellent light intensity and voltage dependences, which can be successfully applied in wireless optical communications. This TpDPP-Py (TpDPP: 5,5'-(2,5-bis(2-ethylhexyl)-3,6-dioxo-2,3,5,6-tetrahydropyrrolo [3,4-c]pyrrole-1,4-diyl)bis(thiophene-2-carbaldehyde), Py: 1,3,6,8-tetrakis(4-aminophenyl)pyrene) COF film will largely promote the development of NIR neuromorphic optoelectronics, thus expanding applications in sustainable and portable devices based on flexible COF film.