Polymer matrix drives thermal stimulation-caused dynamic phosphorescence in dispersed chromophores

Polymer matrix has been extensively explored for decades to achieve efficient room-temperature phosphorescence from dispersed chromophores. However, the impact of the polymer matrix on the optical characteristics of chromophores remains elusive. Herein, we report that different asymmetric environments of polymer matrix delicately regulate the thermally stimulated phosphorescence property (estimated maximum total Φ_PL: 92% at 298 K) of the molecularly dispersed chromophores. It essentially controls the degree of exo- and endothermic transition of excited states with the same and different multiplicity. The excited-state calculations demonstrate a significant influence of matrix environment on the dynamic phosphorescence property. Furthermore, we have investigated the impact of matrix-assisted conformers on dynamic phosphorescence for BANHPh and BANMePh in contrast to the completely locked geometry of BANH2. These matrix-induced, tunable phosphorescent emitters have been found to be highly competent in applications such as information encryption and afterglow display.