Regulation of Irradiation‐Dependent Long‐Lived Room Temperature Phosphorescence by Controlling Molecular Structures of Chromophores and Matrix

Abstract Long‐lived room temperature phosphorescent (LRTP) materials have attracted widespread attention due to their unique luminescence phenomenon and application prospects in the fields of information encryption and bioimaging. However, achieving intelligent response LRTP from amorphous polymers under atmospheric conditions is fascinating but challenging. Here, a series of irradiation‐dependent LRTP systems with ultralong phosphorescent lifetime and high quantum yields are fabricated by a consuming triplet oxygen strategy, and the LRTP performance exhibits obvious chromophore structure and polymeric molecular weight dependence. By extending the UV irradiation time, the phosphorescence lifetime can be increased by hundreds of times, which can exceed 2 s. Experimental results prove that the molecular weight of the polymer matrix, the doping concentration, and the structure of the chromophore have a crucial influence on the stimulus‐response speed and phosphorescence properties of the materials. This kind of intelligent and irradiation‐dependent LRTP material has excellent application prospects in the field of multi‐level information encryption. This work will effectively promote the development of stimulus‐responsive LRTP materials under atmospheric conditions.