Intrinsically Crosslinked Self-Assembled Long-Lived Polymeric Room-Temperature Phosphorescent Microspheres
Room-temperature phosphorescence (RTP) polymer materials are attractive for flexible electronics and information encryption due to their tunability and processability. However, achieving polymeric RTP systems that simultaneously exhibit high thermal sensitivity, reversible multicolor emission, and long phosphorescence lifetime (τPhos) with high quantum yield (ΦPhos) remains challenging. Here, we report an in-situ cross-linked self-assembly strategy that converts flexible polymers into rigid polymer microspheres, yielding long τPhos, high ΦPhos, and thermally and time-dependent tunable RTP. The resulting microspheres (PM0.1-0.01-1) exhibit a maximum τPhos of 1754 ms and ΦPhos of 42.83%, markedly superior to previously reported intrinsic polymer RTP materials. At 77 K, they display ultralong green emission with a lifetime of 6019 ms and visible afterglow lasting up to 99 s. The cross-linked microspheres enable time-dependent, continuously tunable RTP and thermally responsive color switching, while maintaining excellent phosphorescence stability in aqueous and high-temperature environments. This provides a versatile platform for dynamic information encryption, full-color afterglow LEDs, and temperature sensing. The strategy establishes a general design principle for developing multidimensional, controllable, and stable high-performance polymer RTP materials.