Controlling the Emitter Orientation in Solution-processed Films through Introduction of Mesogenic Groups within a Multi-resonance Thermally Activated Delayed Fluorescence Emitter
Controlling the Emitter Orientation in Solution-processed Films through Introduction of Mesogenic Groups within a Multi-resonance Thermally Activated Delayed Fluorescence Emitter
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DOI：
10.26434/chemrxiv-2022-dc4zm
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发表时间：
2022-02
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通讯作者：
Dongyang Chen;F. Tenopala‐Carmona;Julius A Knöller;A. Mischok;David Hall;S. Suresh;Tomas Matulaitis;Y. Olivier;Pierre Nacke;F. Giesselmann;S. Laschat;M. Gather;E. Zysman‐Colman
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作者：
Dongyang Chen;F. Tenopala‐Carmona;Julius A Knöller;A. Mischok;David Hall;S. Suresh;Tomas Matulaitis;Y. Olivier;Pierre Nacke;F. Giesselmann;S. Laschat;M. Gather;E. Zysman‐Colman
使用热激活延迟荧光发射体和显示其跃迁偶极的优先水平取向的发射体是两种新兴的提高有机发光二极管效率的策略。我们提出了液晶多共振热激活延迟荧光发射器，DiKTaLC的第一个例子。纯DiKTaLC薄膜的光致发光量子产率为41%，单重态-三重态能隙ΔEST为0.20 eV，延迟寿命τd为70.2 µs。该化合物在80 °C至110 °C之间具有双分散液晶相。更重要的是，旋涂膜的跃迁偶极矩显示出优先的水平取向，各向异性因子a为0.26。因此，我们证明了第一次如何自组装的液晶TADF发射器可以导致到目前为止难以捉摸的控制在溶液处理的薄膜中的跃迁偶极子的取向，这将是相关的高性能的溶液处理的有机发光二极管。
The use of thermally activated delayed fluorescence emitters and emitters that show preferential horizontal orientation of their transition dipole are two emerging strategies to enhance the efficiency of organic light-emitting diodes. We present the first example of a liquid crystalline multi-resonance thermally activated delayed fluorescent emitter, DiKTaLC. The neat film of DiKTaLC shows a photoluminescence quantum yield of 41%, a singlet-triplet energy gap, ΔEST, of 0.20 eV, and a delayed lifetime, τd, of 70.2 µs. The compound possesses a nematic discotic liquid crystalline phase between 80 °C and 110 °C. More importantly, the transition dipole moment of the spin-coated film shows preferential horizontal orientation, with an anisotropy factor, a, of 0.26. We thus demonstrate for the first time how self-assembly of a liquid crystalline TADF emitter can lead to the so-far elusive control of the orientation of the transition dipole in solution-processed films, which will be of relevance for high-performance solution-processed organic light-emitting diodes.