Visible‐Light Manipulated Reversible and Ultralong Phosphorescence of Carbon Dots Through Dynamic Cross‐Linking

Abstract Dynamic organic room‐temperature phosphorescence (RTP) materials are highly promising for various applications. However, developing photo‐responsive RTP systems with simple fabrication, high reversibility, and visible‐light responsiveness presents a significant challenge. Herein, in situ embedding of boron‐doped carbon dots (B‐CDs) in amorphous polymer (pPBA) is achieved by a two‐step polymerization and carbonization process. Impressively, the B‐CDs@pPBA composite exhibits visible‐light‐activated ultralong RTP with full reversibility and a lifetime on–off ratio exceeding 280. By correlating photophysical properties with structural characterization results, it is concluded that photoinduced intensifying of the crosslinking between B‐CDs and pPBA is responsible for the dynamic RTP. More interestingly, the B‐CDs@pPBA film is found to display bending actuation and reversible deformable behavior upon light exposure. Finally, potential applications of such photo‐responsive systems in programmable information storage and encryption are demonstrated. This research may pave a new way for the development of dynamic RTP nanomaterials and promote their use in a wide range of promising applications.