By YANG Bai's Group

Carbonized polymer dots (CPDs) are emerging luminescent nanomaterials with polymer structures and a certain degree of carbonization. They exhibit distinct advantages, such as superior fluorescence, low toxicity, great stability, and ease of manufacture. Here, we realize metal-free room temperature phosphorescence (RTP) in CPDs for the first time via universal, green, and cost-effective hydrothermal crosslinking-polymerization process. The efficient methods allow the manufacture of CPDs with unique RTP properties in air without additional metal complexation or complicated matrix composition. The abundant energy levels in CPDs increase the probability of intersystem crossing and the covalently crosslinked framework structures greatly suppress the nonradiative transitions. Furthermore, we find that RTP is associated with crosslink-enhanced emission effect, which provides further routes to design improved CPDs with diverse RTP performance.

Our findings promote fundamental understanding and shine a new light on the problem of generating metal-free RTP materials. The respective work was published in the prestigious journal Angewandte Chemie in January 2018 (Angew. Chem. Int. Ed. 2018, 57, 2393-2398. Hot Paper))