Mesogenic Groups Control the Emitter Orientation in Multi-Resonance TADF Emitter Films.
Mesogenic Groups Control the Emitter Orientation in Multi-Resonance TADF Emitter Films.
复制标题
介晶基团控制多共振 TADF 发射体薄膜中的发射体方向。
DOI：
10.1002/anie.202218911
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Chen D
中科院分区：
文献类型：
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作者：
Chen D
使用热激活延迟荧光（TADF）发射体和显示其跃迁偶极矩（TDM）的优先水平取向的发射体是两种新兴的提高OLED效率的策略。我们提出了液晶多共振TADF（MR-TADF）发射器DiKTa-LC的第一个例子。该化合物在80 °C和110 °C之间具有双相液晶相。重要的是，旋涂膜的TDM显示出优先的水平取向，各向异性因子α为0.28，这在掺杂的聚（乙烯基咔唑）膜中得以保留。基于DiKTa-LC的绿色发射（λEL=492 nm）溶液处理的OLED显示出13.6%的EQE max。因此，我们首次证明了液晶TADF发射体的自组装如何导致迄今为止难以控制的溶液加工膜中跃迁偶极子的取向，这将与高性能溶液加工OLED相关。
The use of thermally activated delayed fluorescence (TADF) emitters and emitters that show preferential horizontal orientation of their transition dipole moment (TDM) are two emerging strategies to enhance the efficiency of OLEDs. We present the first example of a liquid crystalline multi‐resonance TADF (MR‐TADF) emitter,DiKTa‐LC. The compound possesses a nematic liquid crystalline phase between 80 °C and 110 °C. Importantly, the TDM of the spin‐coated film shows preferential horizontal orientation, with an anisotropy factor,a, of 0.28, which is preserved in doped poly(vinylcarbazole) films. Green‐emitting (λEL=492 nm) solution‐processed OLEDs based onDiKTa‐LCshowed an EQEmaxof 13.6 %. 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 OLEDs.