Xue Peiran, Wang Xin, Wang Wuji, Zhang Jingyu, Wang Zijie, Jin Jibiao, Zheng Chao, Li Ping, Xie Guohua, Chen Runfeng
State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nan-jing 210023, China.
Sauvage Center for Molecular Sciences, Hubei Key Lab on Organic and Polymeric Optoelec-tronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, China.
ACS Appl Mater Interfaces. 2021 Oct 13;13(40):47826-47834. doi: 10.1021/acsami.1c13564. Epub 2021 Sep 29.
Circularly polarized luminescence (CPL) molecules, especially those with thermally activated delayed fluorescence (TADF) properties, have attracted considerable attention due to their great potential for chiroptical organic light emitting diode (OLED) devices. Here we developed a new pair of TADF emitters with CPL based on boron complexes using chiral donor (cD) binaphthalene, acceptor (A) biphenyl boron β-diketonate, and donor (D) biphenylamine in a cD-A-D architecture. With this design, both efficient intramolecular charge transfer (ICT) and chiral ICT for high-performance CPL were established, leading to high dissymmetry factors (||) up to 2.2 × 10 in solution and significantly red-shifted emission around 600 nm for red TADF with a quantum yield over 15% in doped films. More impressively, with these chiral TADF emitters, solution-processed red circularly polarized OLEDs (CP-OLEDs) exhibit external quantum efficiencies (EQEs) up to 2.0% and efficient circularly polarized electroluminescence with dissymmetry factors of 2.6 × 10, which are among the best performances of the reported solution-processed orange-red and red TADF CP-OLEDs. These results illustrate the great success of the cD-A-D strategy in designing high-performance CPL TADF emitters with axially chiral boron complexes, providing important clues to understand efficient chiral transfer for large || values and high device performance of CP-OLEDs.
圆偏振发光（CPL）分子，尤其是那些具有热激活延迟荧光（TADF）特性的分子，因其在手性有机发光二极管（OLED）器件中的巨大潜力而备受关注。在此，我们基于硼配合物，利用手性供体（cD）联萘、受体（A）联苯硼β - 二酮酸酯和供体（D）联苯胺，以cD - A - D结构开发了一对新的具有CPL的TADF发光体。通过这种设计，建立了用于高性能CPL的高效分子内电荷转移（ICT）和手性ICT，在溶液中产生了高达2.2×10的高不对称因子（||），并且对于掺杂薄膜中量子产率超过15%的红色TADF，发射峰显著红移至600 nm左右。更令人印象深刻的是，使用这些手性TADF发光体，溶液处理的红色圆偏振OLED（CP - OLED）的外量子效率（EQE）高达2.0%，并且具有2.6×10的不对称因子的高效圆偏振电致发光，这是已报道的溶液处理的橙红色和红色TADF CP - OLED的最佳性能之一。这些结果表明，cD - A - D策略在设计具有轴向手性硼配合物的高性能CPL TADF发光体方面取得了巨大成功，为理解大||值的高效手性转移和CP - OLED的高器件性能提供了重要线索。
