We report intense dopant-matrix afterglow systems with an afterglow efficiency (Φ AG ) of 47% and an afterglow lifetime (τ AG ) of 1.3 s. Luminescent difluoroboron β-diketonate (BF 2 bdk) dopants and their deuterated counterparts are designed with naphthalene and carboxylic acid groups. After doping into benzoic acid (BA) matrices, room-temperature afterglow brightness and afterglow duration of the BF 2 bdk-BA materials have unexpectedly been found to reach the levels of those at 77 K, which indicates that hydrogen bonding between BF 2 bdk and BA, as well as the deuteration technique, can reduce k nr + k q of BF 2 bdk triplets to very small values even at room temperature. Detailed studies reveal that the BF 2 bdk possesses typical 1 ICT characters in the S 1 state and distinct 3 LE composition in the T 1 state, and thus shows a high Φ ISC and a small k P to obtain a high Φ AG and a long τ AG . Besides, triplet−triplet annihilation has been found in the dopant-matrix system at high doping concentrations to further increase Φ AG .

When compared to their fluorescence counterparts, stimuli-responsive organic afterglow materials exhibit distinct advantages to function normally even in the presence of strong background fluorescence. However, the types of these 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 TADFtype 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.