Cheng Ying-Chun, Fan Xiao-Chun, Huang Feng, Xiong Xin, Yu Jia, Wang Kai, Lee Chun-Sing, Zhang Xiao-Hong
Institute of Functional Nano & Soft Materials (FUNSOM), Joint International Research Laboratory of Carbon-Based Functional Materials and Devices, Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
Angew Chem Int Ed Engl. 2022 Nov 21;61(47):e202212575. doi: 10.1002/anie.202212575. Epub 2022 Oct 20.
Multiple resonance (MR) type thermally activated delayed fluorescence (TADF) material is currently a research hotspot in organic light-emitting diodes (OLEDs) due to their high color purity and high exciton utilization. However, there are only a handful of MR-TADF emitters with emissions beyond the blue-to-green region. The very limited emission colors for MR-TADF emitters are mainly caused by the fact that so far molecular modifications of MR-TADF do not offer much change in the emission colors. Here, we report a new approach to modifying a prototypical MR core of DABNA by fusing carbazoles to the MR framework. The carbazole-fused molecule (TCZ-F-DABNA) basically maintains the MR-dominated features of DABNA while red-shifting the emission. Its OLED achieves an external quantum efficiency of 39.2 % with a peak at 588 nm, which is a record-high efficiency for OLEDs with peaks beyond 560 nm. This work provides a new approach for significantly tunning emission colors of MR-TADF emitters.
多重共振（MR）型热激活延迟荧光（TADF）材料由于其高色纯度和高激子利用率，目前是有机发光二极管（OLED）领域的一个研究热点。然而，只有少数几种发射波长超出蓝绿色区域的MR-TADF发光体。MR-TADF发光体的发射颜色非常有限，主要是因为到目前为止，MR-TADF的分子修饰在发射颜色上并没有太大变化。在此，我们报道了一种通过将咔唑融合到MR骨架上来修饰典型的DABNA的MR核心的新方法。咔唑融合分子（TCZ-F-DABNA）在保持DABNA的MR主导特征的同时，使发射波长红移。其OLED在588nm处实现了39.2%的外量子效率峰值，这是峰值超过560nm的OLED的创纪录高效率。这项工作为显著调节MR-TADF发光体的发射颜色提供了一种新方法。
