Temperature dependent triplet-exciton relay from thermally activated delayed fluorescence (TADF) to self-sensitized triplet–triplet annihilation (TTA) of asymmetrical diphenylsulfone-based blue emitter

Designing thermally activated delayed fluorescence emitters with through-space charge transfer: a theoretical study

“…S4, ESI †), further confirming intramolecular interactions in the compounds. 20,[73][74][75] Fig. 2 presents the calculated excited state properties of AC-BO, QAC-BO, DQAC-DBO, DQAC-SBO, and DQAC-NBO in the gas state.…”

“…18 The reduction of efficiency roll-off can be achieved by enhancing K RISC . [19][20][21][22][23] TADF molecules with through-bond charge transfer (TBCT) properties have been synthesized by constructing p-conjugated donor-acceptor (D-p-A) molecular structures. [24][25][26][27] Furthermore, the nonplanar configuration can weaken intermolecular stacking interactions, suppressing the quenching effect due to aggregation.…”

Realization of highly efficient organic emitting diodes using thermally activated delayed fluorescence (TADF) materials with fast reverse intersystem crossing

“…According to the first-order perturbation theory, k RISC is proportional to the spin–orbit coupling matrix element (〈S| Ĥ soc |T〉) between singlet and triplet states and is inversely proportional to Δ E ST . 18,19 Generally, minimizing Δ E ST would be realized by using twisted D–A molecular structures, which inevitably decreases the value of 〈S| Ĥ soc |T〉. Such a trade-off originates from the inefficient RISC between the singlet CT excited state and triplet CT excited state, thereby minimizing Δ E ST and making it technically impractical to improve k RISC .…”