Molecular engineering by σ-linkers enables delayed fluorescence emitters for high-efficiency sky-blue solution-processed OLEDs
Molecular engineering by σ-linkers enables delayed fluorescence emitters for high-efficiency sky-blue solution-processed OLEDs
复制标题
α-连接体的分子工程可实现延迟荧光发射器，用于高效天蓝色溶液处理的 OLED
DOI：
10.1016/j.cej.2021.133078
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发表时间：
2022
影响因子：
15.1
通讯作者：
Yang Chuluo
中科院分区：
文献类型：
--
作者：
Chen Yanying;Li Nengquan;Huang Zhongyan;Xie Guohua;Yang Chuluo
基于9,9-二甲基吖啶给体和刚性氧桥环化硼受体，设计合成了两种新型热激活延迟荧光（TADF）发射体Me2AcBO和F2AcBO，用于高效蓝色溶液处理有机发光二极管（oled）。Me2AcBO和F2AcBO具有通过非共轭连接剂偶联两个单独的TADF单体而衍生的双结构。这两种新型发射体具有三维分子结构、优异的热/形态性能、97%以上的高光致发光量子产率和106s−1量级的高系统间逆向交叉率，极大地促进了器件效率的提高。溶液处理的基于Me2AcBO和F2AcBO的天蓝色TADF oled的外部量子效率最高，分别为11.0%和10.9%，国际照明委员会（CIE）坐标为（0.14,0.25）。有趣的是，在亮度为1000 cd/m2时，基于Me2AcBO和基于F2AcBO的器件的效率滚降分别为33%和34%。本研究提出了一种新的策略，以实现高效的天蓝TADF发射器用于溶液处理的oled。
Two novel thermally activated delayed fluorescence (TADF) emitters, namely Me2AcBO and F2AcBO, based on the 9,9-dimethrylacridine donor and a rigid oxygen-bridged cyclized boron acceptor, were designed and synthesized for highly efficient blue solution-processed organic light-emitting diodes (OLEDs). Me2AcBO and F2AcBO feature a twin structure derived by coupling two individual TADF monomers through non-conjugated linkers. The two new emitters exhibit 3D molecular structures, excellent thermal/morphological properties, high photoluminescence quantum yields over 97%, and high reverse intersystem crossing rates on the order of 106s−1, which greatly benefit the high device efficiency. Solution-processed sky-blue TADF OLEDs based on Me2AcBO and F2AcBO achieved the maximum external quantum efficiency of 11.0% and 10.9%, respectively, with Commission Internationale de L’Eclairage (CIE) coordinates of (0.14, 0.25). Interestingly, relatively low efficiency roll-offs of 33% and 34% at the luminance of 1000 cd/m2were demonstrated for Me2AcBO and F2AcBO based devices, respectively. This study presents a novel strategy to realize highly efficient sky-blue TADF emitters for solution-processed OLEDs.