Liu Huijun, Zeng Jiajie, Guo Jingjing, Nie Han, Zhao Zujin, Tang Ben Zhong
Center for Aggregation-Induced Emission, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, 510640, China.
Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center, for Tissue Restoration and Reconstruction, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China.
Angew Chem Int Ed Engl. 2018 Jul 20;57(30):9290-9294. doi: 10.1002/anie.201802060. Epub 2018 Jun 21.
Non-doped organic light-emitting diodes (OLEDs) possess merits of higher stability and easier fabrication than doped devices. However, luminescent materials with high exciton use are generally unsuitable for non-doped OLEDs because of severe emission quenching and exciton annihilation in neat films. Herein, we wish to report a novel molecular design of integrating aggregation-induced delayed fluorescence (AIDF) moiety within host materials to explore efficient luminogens for non-doped OLEDs. By grafting 4-(phenoxazin-10-yl)benzoyl to common host materials, we develop a series of new luminescent materials with prominent AIDF property. Their neat films fluoresce strongly and can fully harvest both singlet and triplet excitons with suppressed exciton annihilation. Non-doped OLEDs of these AIDF luminogens exhibit excellent luminance (ca. 100000 cd m ), outstanding external quantum efficiencies (21.4-22.6 %), negligible efficiency roll-off and improved operational stability. To the best of our knowledge, these are the most efficient non-doped OLEDs reported so far. This convenient and versatile molecular design is of high significance for the advance of non-doped OLEDs.
非掺杂有机发光二极管（OLED）具有比掺杂器件更高的稳定性和更易于制造的优点。然而，由于纯薄膜中存在严重的发射猝灭和激子湮灭，具有高激子利用率的发光材料通常不适用于非掺杂OLED。在此，我们希望报道一种新颖的分子设计，即在主体材料中整合聚集诱导延迟荧光（AIDF）部分，以探索用于非掺杂OLED的高效发光体。通过将4-（吩恶嗪-10-基）苯甲酰基接枝到常见的主体材料上，我们开发了一系列具有突出AIDF特性的新型发光材料。它们的纯薄膜发出强烈的荧光，并且可以在抑制激子湮灭的情况下充分捕获单线态和三线态激子。这些AIDF发光体的非掺杂OLED表现出优异的亮度（约100000 cd·m⁻²）、出色的外量子效率（21.4 - 22.6%）、可忽略不计的效率滚降和改善的工作稳定性。据我们所知，这些是迄今为止报道的效率最高的非掺杂OLED。这种方便且通用的分子设计对于非掺杂OLED的发展具有重要意义。
