Li Yungui, Wei Qiang, Cao Liang, Fries Felix, Cucchi Matteo, Wu Zhongbin, Scholz Reinhard, Lenk Simone, Voit Brigitte, Ge Ziyi, Reineke Sebastian
Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP), Institute for Applied Physics, Technische Universität Dresden, Dresden, Germany.
Ningbo Institute of Materials Technology & Engineering, Chinese Academy Sciences, Ningbo, China.
Front Chem. 2019 Oct 23;7:688. doi: 10.3389/fchem.2019.00688. eCollection 2019.
In this work, interactions between different host materials and a blue TADF polymer named P1 are systematically investigated. In photoluminescence, the host can have substantial impact on the photoluminescence quantum yield (PLQY) and the intensity of delayed fluorescence ( ), where more than three orders of magnitude difference of in various hosts is observed, resulting from a polarity effect of the host material and energy transfer. Additionally, an intermolecular charge-transfer (CT) emission with pronounced TADF characteristics is observed between P1 and 2,4,6-tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine (PO-T2T), with a singlet-triplet splitting of 7 meV. It is noted that the contribution of harvested triplets in monochrome organic light-emitting diodes (OLEDs) correlates with . For devices based on intermolecular CT-emission, the harvested triplets contribute ~90% to the internal quantum efficiency. The results demonstrate the vital importance of host materials on improving the PLQY and sensitizing of TADF polymers for efficient devices. Solution-processed polychrome OLEDs with a color close to a white emission are presented, with the emission of intramolecular (P1) and intermolecular TADF (PO-T2T:P1).
在这项工作中，系统地研究了不同主体材料与一种名为P1的蓝色热激活延迟荧光（TADF）聚合物之间的相互作用。在光致发光方面，主体对光致发光量子产率（PLQY）和延迟荧光强度有重大影响，在各种主体中观察到延迟荧光强度存在三个多数量级的差异，这是由主体材料的极性效应和能量转移导致的。此外，在P1与2,4,6-三[3-(二苯基膦酰基)苯基]-1,3,5-三嗪（PO-T2T）之间观察到具有明显TADF特性的分子间电荷转移（CT）发射，其单重态-三重态分裂为7毫电子伏特。值得注意的是，在单色有机发光二极管（OLED）中收集到的三重态的贡献与延迟荧光强度相关。对于基于分子间CT发射的器件，收集到的三重态对内部量子效率的贡献约为90%。结果表明主体材料对于提高PLQY以及使TADF聚合物的延迟荧光敏化以实现高效器件至关重要。展示了溶液处理的多色OLED，其颜色接近白色发射，具有分子内（P1）和分子间TADF（PO-T2T:P1）发射。
