Organic NIR Afterglow with Emission Wavelengths Beyond 800 nm

• • Achieved NIR afterglow at 820 nm, exceeding the previous 780 nm limit for organic afterglow materials, enabling deeper tissue penetration (>1 cm) and higher signal-to-background ratios in bioimaging. • • Utilized alternating D-A structures with thienyl donors and thiazolo[5,4-d]thiazole/benzothiadiazole acceptors to enhance intramolecular charge transfer (ICT), resulting in a reduced energy gap and efficient triplet exciton stabilization. • • Incorporated multiple S···O intramolecular interactions to strengthen molecular rigidity and suppress nonradiative decays, yielding afterglow lifetimes suitable for persistent imaging (e.g., >100 ms) and high photostability. • • Optimized terminal groups and side chains to control intermolecular interactions, reducing aggregation-caused quenching and achieving high afterglow quantum yields (e.g., >10%) under ambient conditions.