Thermally activated delayed fluorescence (TADF) emitters have only realized limited performance in solution-processed organic light-emitting diodes (OLEDs) comparing to in evaporation-processed OLEDs. To address this issue, a novel D-D′-A structure, where A is the electron-accepting group, D is the primary electron-donating group and D′ is the secondary electron-donating group, was proposed to develop efficient solution-processable TADF emitters in this work. As the intermediate D′ spacer weakens the direct intramolecular interaction between D and A groups, D-D′-A structure molecules simultaneously possess intramolecular and intermolecular charge-transfer transition channels, suppressing the aggregation-caused quenching induced by solution process. Accordingly, a novel TADF emitter 2-(3,6-bis(9,9-dimethylacridin-10(9H)-yl)-9H-carbazol-9-yl)thianthrene 5,5,10,10-tetraoxide (DMAC-Cz-TTR) was designed and synthesized. In the optimized evaporation- and solution-processed OLEDs, DMAC-Cz-TTR successfully realized similar maximum external quantum efficiencies (EQEs) of 21.1% and 20.6%, respectively. To the best of our knowledge, this is the first TADF emitter realizing nearly equal performance in both evaporation- and solution-processed OLEDs with over 20% EQEs. The outstanding performance of DMAC-Cz-TTR successfully demonstrates the feasibility of the D-D′-A structure to develop efficient solution-processable TADF emitters.

与蒸发处理的 OLED 相比，热激活延迟荧光 (TADF) 发射器在溶液处理的有机发光二极管 (OLED) 中仅实现了有限的性能。为了解决这个问题，提出了一种新的 DD'-A 结构，其中 A 是受电子基团，D 是初级给电子基团，D' 是二次给电子基团，以开发高效的可溶液加工的 TADF在这项工作中的发射器。由于中间的 D' 间隔区削弱了 D 和 A 基团之间的直接分子内相互作用，DD'-A 结构分子同时具有分子内和分子间电荷转移通道，抑制了溶液过程引起的聚集引起的猝灭。因此，一种新型的 TADF 发射体 2-(3,6-bis(9, 设计并合成了9-二甲基吖啶-10(9H)-基)-9H-咔唑-9-基)噻蒽5,5,10,10-四氧化物(DMAC-Cz-TTR)。在优化的蒸发和溶液处理 OLED 中，DMAC-Cz-TTR 分别成功实现了类似的最大外量子效率 (EQE)，分别为 21.1% 和 20.6%。据我们所知，这是第一个在蒸发处理和溶液处理 OLED 中实现几乎相同性能的 TADF 发射器，EQE 超过 20%。DMAC-Cz-TTR 的出色性能成功证明了 DD'-A 结构开发高效可溶液处理 TADF 发射器的可行性。分别为 1% 和 20.6%。据我们所知，这是第一个在蒸发处理和溶液处理 OLED 中实现几乎相同性能的 TADF 发射器，EQE 超过 20%。DMAC-Cz-TTR 的出色性能成功证明了 DD'-A 结构开发高效可溶液处理 TADF 发射器的可行性。分别为 1% 和 20.6%。据我们所知，这是第一个在蒸发处理和溶液处理 OLED 中实现几乎相同性能的 TADF 发射器，EQE 超过 20%。DMAC-Cz-TTR 的出色性能成功证明了 DD'-A 结构开发高效可溶液处理 TADF 发射器的可行性。