Design and Preparation of Multicolor Long‐Lifetime Fluorescent Material Based on Charge‐Separated States

Abstract Afterglow materials have the advantages of long luminescent lifetime and large stokes shift, which show good application prospects in fields such as probes, anti‐counterfeiting, and organic light‐emitting diode (OLED). Nevertheless, the preparation of multicolor long afterglow materials with simple components remains a challenge. This article proposes a general strategy for preparing room temperature long‐lifetime fluorescent polymer materials. This strategy involves doping various fluorescent small molecules containing electron‐donating groups into polymers containing electron‐withdrawing groups. The results show the two components can form charge‐separated state by long‐range charge transfer, and the excitons recombined in fluorescent molecules and emitted long‐lived fluorescence. After photoactivation, the P3COMe film doped with 1% RhB can emit red fluorescent afterglow. The lifetime can achieve 39.4 ms, and the afterglow can last 4.17 s. Meanwhile, by introducing fluorescent molecules with different luminescent colors, the multicolor long‐lifetime fluorescence is also realized. In addition, the influence of the structure of luminescent small molecules on the afterglow fluorescent properties of their doped films is also elucidated.