Liu Yanyan, Yang Jiaji, Mao Zhu, Chen Xiaojie, Yang Zhan, Ge Xiangyu, Peng Xiaomei, Zhao Juan, Su Shi-Jian, Chi Zhenguo
PCFM Lab, GD HPPC Lab, Guangdong Engineering Technology Research Centre for High-performance Organic and Polymer Photoelectric Functional Films, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry, Sun Yat-sen University, Guangzhou 510275, China.
State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640, China.
ACS Appl Mater Interfaces. 2022 Jul 27;14(29):33606-33613. doi: 10.1021/acsami.2c07617. Epub 2022 Jul 12.
Developing highly efficient red/near-infrared thermally activated delayed fluorescence (TADF) materials is of great importance for organic light-emitting diodes (OLEDs). Here, we reported an asymmetric TADF emitter (TCPQ), which exhibits a high reverse intersystem crossing rate as well as a low non-radiative rate due to molecular symmetry breaking through multiple donor substitution. The coexistence of multiple donors endows TCPQ with not only near-infrared emission but also excellent device performances. As for the TCPQ-based OLEDs, the 10 and 20 wt % doped devices exhibit outstanding external quantum efficiencies (EQEs) of 21.9 and 19.2% with red emission peaks at 612 and 642 nm, respectively. Meanwhile, the non-doped device achieves an EQE of 5.4% with an emission peak at 718 nm, showing near-infrared emission. These device efficiencies are among the best performances of red/near-infrared TADF-OLEDs, demonstrating that the asymmetry design is a potential strategy for constructing long wavelength TADF materials with high efficiency.
开发高效的红色/近红外热激活延迟荧光（TADF）材料对于有机发光二极管（OLED）至关重要。在此，我们报道了一种不对称TADF发射体（TCPQ），由于通过多个供体取代打破了分子对称性，它表现出高的反向系间窜越率以及低的非辐射率。多个供体的共存不仅赋予TCPQ近红外发射特性，还使其具有出色的器件性能。对于基于TCPQ的OLED，10 wt%和20 wt%掺杂的器件分别在612和642 nm处呈现红色发射峰，具有21.9%和19.2%的出色外量子效率（EQE）。同时，非掺杂器件在718 nm处有发射峰，实现了5.4%的EQE，呈现近红外发射。这些器件效率在红色/近红外TADF-OLED的最佳性能之列，表明不对称设计是构建高效长波长TADF材料的一种潜在策略。
