2D Triazine Covalent Organic Frameworks for Ultrafast Self‐Powered Green‐Light Photodetection

Covalent organic frameworks (COFs) are crystalline porous materials constructed by covalently linking organic monomers, offering advantages such as lightweight, high thermal stability, and tunable bandgaps. In this study, p-type Tp-TTA COF films with a covalent triazine backbone are synthesized via an interfacial synthesis method and integrated with n-type silicon (n-Si) to form a 2D Triazine COF-based photodetectors. The p-type Tp-TTA COF/n-Si green light self-powered photodetector exhibits ultrafast response times (rise time of 60 µs, decay time of 47 µs). Its ultrafast response speed enables it to outperform all current COF-based photodetectors and most self-powered green light photodetectors based on 2D materials. Furthermore, the obtained p-type Tp-TTA COF films show excellent self-supporting properties and flexibility, fabricating a novel freestanding flexible metal-semiconductor-metal (MSM) structure Tp-TTA COF photodetector. After 90 bending cycles, the optical response of the freestanding flexible MSM-structure Tp-TTA COF photodetector shows minimal degradation (only 0.7%), demonstrating its potential for flexible and wearable devices. This study not only expands the application prospects of COF materials in the optoelectronic field but also offers new insights for the design of flexible multifunctional devices, highlighting the broad transformation potential of COFs as a new class of functional materials.