Donor engineering for diphenylsulfone derivatives with both thermally activated delayed fluorescence and aggregation-induced emission properties

Aggregation-induced emission active thermally-activated delayed fluorescence materials possessing N-heterocycle and sulfonyl groups

“…The rate constants for ISC (k ISC ) and RISC (k RISC ) for 2Cz2SB were estimated to be the order of 10 7 and 10 4 s À1 , respectively, which are typical for TADF materials possessing sulfonyl groups. 14,38,39 On the other hand, k ISC and k RISC for 2Mi2SB were the order of 10 8 and 10 6 s À1 , respectively, which are much larger than those of 2Cz2SB. Although unfortunately F PL of 2Mi2SB is not so high probably due to nonradiative deactivation, the Mi moiety can be positioned as one of the better donor parts for TADF materials.…”

Aggregation‐induced emission luminogens for organic light‐emitting diodes with a single‐component emitting layer

“…[76] The resultant material showed dualcharge transfer pathways, that is, intramolecular electrostatic attraction and through-space charge transfer (TSCT) because the Cz donor and DPS acceptor groups were connected at the ortho-position to achieve the spatially close D-A interaction. The dual charge transfer process significantly increased the oscillator strength (f = 0.0207) for faster radiative decay, in comparison with the linearly linked conformation of 4Cz-DPS (f = 0.0074), exhibiting a high PLQY of 91 [77] The materials were prepared with an asymmetric configuration to understand the effect of donor In 2015, Adachi's group constructed nondoped OLEDs with a symmetrical D-A-D configuration and obtained excellent EL performances (EQE max = 18.9%) and negligible efficiency roll-off by using benzophenone, instead of DPS as the acceptor. [5c] In 2017, the same group developed three AIDF emitters with an asymmetric D-A-Dʹ configuration by using dibenzothiophene (DBT) as the donor, benzophenone as the acceptor, and PXZ, PTZ, and DMAC as another donor; these emitters were named DBT−BZ−PXZ, DBT−BZ−PTZ, and DBT-BZ-DMAC.…”

“…A nondoped OLED constructed based on 2Cz–DPS with the configuration of ITO/PEDOT:PSS (30 nm)/mCP (20 nm)/2Cz–DPS (30 nm)/TPBI (40 nm)/LiF (1 nm)/Al exhibited a record‐high EL performances with EQE max , CE max , and PE max values of 28.7%, 82.3 cd A −1 , and 51.8 lm W −1 , respectively. Two D–A–Dʹ‐configured AIDF luminogens based on DPS derivatives, namely, 3CP–DPS–PXZ and 3CP–DPS–DMAC, were explored by Wang et al [77] . The materials were prepared with an asymmetric configuration to understand the effect of donor on their luminescence properties with different donors Dʹ, namely, PXZ and DMAC, herein, 9‐phenylcarbazole was as the fixed donor D. Both emitters exhibited clear AIE behavior, high PLQY in the neat film, as well, observed a very small Δ E ST of 0.03–0.07 eV.…”

Recent progress in thermally activated delayed fluorescence emitters for nondoped organic light-emitting diodes

“…Wang et al also reported two asymmetric AIDF emitters 116 and 117 by using DMAC/PXZ, DPS, and PCz as the D, A, and D′ moieties, respectively. 109 Introducing the PCz moiety can effectively restrain the intermolecular interactions in the aggregated states. Therefore, both emitters exhibit typical AIDF characteristics.…”