Tang Rui, Xu Shuo, Lam Tsz-Lung, Cheng Gang, Du Lili, Wan Qingyun, Yang Jun, Hung Faan-Fung, Low Kam-Hung, Phillips David Lee, Che Chi-Ming
Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China.
Department of Chemistry, South University of Science and Technology of China, Shenzhen, Guangdong 518055, P. R. China.
Angew Chem Int Ed Engl. 2022 Aug 15;61(33):e202203982. doi: 10.1002/anie.202203982. Epub 2022 Jun 23.
A critical step in advancing the practical application of copper-based organic light-emitting diodes (OLEDs) is to bridge the large gap between device efficiency and operational stability at practical luminance. Described is a panel of air- and thermally stable two-coordinate Cu emitters featuring bulky pyrazine- (PzIPr) or pyridine-fused N-heterocyclic carbene (PyIPr*) and carbazole (Cz) ligands with enhanced amide-Cu-carbene bonding interactions. These Cu emitters display thermally activated delayed fluorescence (TADF) from the LL'CT(Cz→PzIPr/PyIPr*) excited states across the blue to red regions with exceptional radiative rate constants of 1.1-2.2×10 s . Vapour-deposited OLEDs based on these Cu emitters showed excellent external quantum efficiencies and luminance up to 23.6 % and 222 200 cd m , respectively, alongside record device lifetimes (LT ) up to 1300 h at 1000 cd m under our laboratory conditions, highlighting the practicality of the Cu -TADF emitters.
推动铜基有机发光二极管（OLED）实际应用的关键一步是弥合器件效率与实际亮度下的运行稳定性之间的巨大差距。本文描述了一组具有空气稳定性和热稳定性的双配位铜发光体，其特点是含有体积较大的吡嗪基（PzIPr）或吡啶稠合的N-杂环卡宾（PyIPr*）以及咔唑（Cz）配体，具有增强的酰胺-铜-卡宾键相互作用。这些铜发光体在从蓝色到红色的区域内，从LL'CT（Cz→PzIPr/PyIPr*）激发态显示出热激活延迟荧光（TADF），其辐射速率常数高达1.1 - 2.2×10 s 。基于这些铜发光体的气相沉积OLED分别显示出高达23.6%和222200 cd m 的出色外量子效率和亮度，同时在我们的实验室条件下，在1000 cd m 时记录的器件寿命（LT）长达1300小时，突出了铜-TADF发光体的实用性。
