Zhao Juewen, Ye Jun, Du Xiaoyang, Zheng Caijun, He Zeyu, Yang Haoyu, Zhang Ming, Lin Hui, Tao Silu
School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054, P. R. China.
School of Materials Science and Chemical Engineering, Ningbo, 315211, P. R. China.
Chem Asian J. 2020 Dec 1;15(23):4093-4097. doi: 10.1002/asia.202001091. Epub 2020 Nov 4.
Widely investigated thermally activated delayed fluorescence (TADF) can be achieved by intramolecular and intermolecular charge transfer between an electron donor and electron acceptor which corresponds to a TADF material and exciplex, respectively. However, the development of efficient organic light-emitting diodes (OLEDs) based on an exciplex lags far behind the development of those based on efficient TADF materials. In this work, a novel D-A type electron donor TPAFPO was designed and synthesized. TPAFPO:PO-T2T exhibits a small ΔE of 79 meV and significant delayed emission, demonstrating TADF characteristics. OLEDs based on TPAFPO:PO-T2T exhibit a low turn-on voltage of 2.4 V and high an EQE value of 17.0%. Besides, NIR OLEDs utilizing TPAFPO:PO-T2T as host exhibit a turn-on voltage of 3.0 V and high EQE of 9.2% with a NIR emission peak at 690 nm. Furthermore, solution-processed exciplex and NIR devices also can maintain high efficiencies of 15.1% and 8.1%, respectively.
被广泛研究的热激活延迟荧光（TADF）可通过电子供体与电子受体之间的分子内和分子间电荷转移来实现，这分别对应于一种TADF材料和激基复合物。然而，基于激基复合物的高效有机发光二极管（OLED）的发展远远落后于基于高效TADF材料的OLED的发展。在这项工作中，设计并合成了一种新型的D-A型电子供体TPAFPO。TPAFPO:PO-T2T表现出79 meV的小ΔE和显著的延迟发射，展现出TADF特性。基于TPAFPO:PO-T2T的OLED具有2.4 V的低开启电压和17.0%的高外量子效率（EQE）值。此外，以TPAFPO:PO-T2T作为主体的近红外OLED具有3.0 V的开启电压和9.2%的高EQE，近红外发射峰位于690 nm处。此外，溶液处理的激基复合物和近红外器件也分别能够保持15.1%和8.1%的高效率。
