Liu Tiantian, Chen Xiaojie, Zhao Juan, Wei Weichun, Mao Zhu, Wu William, Jiao Shibo, Liu Yang, Yang Zhiyong, Chi Zhenguo
PCFM Lab, GDHPPC Lab, Guangdong Engineering Technology, Research Center for High-performance Organic and Polymer Photoelectric Functional Films, State Key Laboratory of OEMT, School of Chemistry, Sun Yat-sen University Guangzhou 510275 China
State Key Laboratory of OEMT, School of Materials Science and Engineering, Sun Yat-sen University Guangzhou 510275 China
Chem Sci. 2021 Feb 23;12(14):5171-5176. doi: 10.1039/d1sc00272d.
Pure organic emitters with full utilization of triplet excitons are in high demand for organic light-emitting diodes (OLEDs). Herein, through modulation of electron donors and introduction of phenyl rings as π spacers, we present three pure organic fluorophores (BCz, BTCz and BPTCz) with the hybridized local and charge-transfer (HLCT) excited state feature for OLED fabrication. Importantly, the introduction of π spacers in BPTCz not only enhances locally excited character with a fast radiative decay but also promotes intermolecular interactions to suppress non-radiative decays, contributing to a high solid-state fluorescence efficiency over 90%. Significantly, BPTCz not only endows its doped OLEDs with an external quantum efficiency (EQE) up to 19.5%, but also its non-doped OLED with a high EQE of 17.8%, and these outstanding efficiencies are the state-of-the-art performances of HLCT-based OLEDs.
对于有机发光二极管（OLED）而言，充分利用三线态激子的纯有机发光体需求旺盛。在此，通过调节电子供体并引入苯环作为π间隔基，我们展示了三种具有杂化局域和电荷转移（HLCT）激发态特征的纯有机荧光团（BCz、BTCz和BPTCz）用于OLED制造。重要的是，在BPTCz中引入π间隔基不仅增强了具有快速辐射衰减的局域激发特性，还促进了分子间相互作用以抑制非辐射衰减，从而实现了超过90%的高固态荧光效率。值得注意的是，BPTCz不仅赋予其掺杂OLED高达19.5%的外量子效率（EQE），还赋予其非掺杂OLED高达17.8%的高EQE，而这些出色的效率是基于HLCT的OLED的最先进性能。
