Polymer-Based TADF-Type Organic Afterglow

Polymer-based organic afterglow materials exhibit excellent flexibility and mechanical properties, whereas their afterglow mainly follows a phosphorescence mechanism with limited afterglow efficiency. Here, we report polymer-based TADF-type afterglow materials, which feature a moderate rate of reverse intersystem crossing of 1–10 s –1 to harvest triplet energies and consequently possess an afterglow efficiency of >80%. By doping a specific difluoroboron diketonate dye into polymer matrices, various polymer-based afterglow materials have been obtained. In particular, afterglow elastomers, which have been rarely reported, have also been achieved with a high efficiency of 50% and a long lifetime of 0.19 s. Variable temperature-delayed emission studies and TD-DFT calculations have been performed to support the TADF afterglow mechanism. This study would pave the way for highly efficient polymer-based organic afterglow materials and their promising applications in diverse areas.