Jin Yu-Xin, Chen Zi-Qi, Zhang Kai, Yang Chen-Zong, Pan Ze-Hui, Ding Lei, Sun Yan-Qiu, Wang Chuan-Kui, Fung Man-Keung, Fan Jian
Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, China.
Shandong Province Key Laboratory of Medical Physics and Image Processing Technology School of Physics and Electronics, Shandong Normal University, 250014, Jinan, China.
Chemistry. 2023 Oct 9;29(56):e202301921. doi: 10.1002/chem.202301921. Epub 2023 Sep 7.
Robust scaffolds were typically applied in thermally activated delayed fluorescence (TADF) molecules to suppress the non-radiative decay, trigger the fast spin-flipping, and enhance the light out-coupling efficiency. Herein, we disclosed for the first time the positive effect of flexible conformation of ancillary groups on the photophysical properties of TADF emitter. The red TADF emitter Ph-TPA with flexible conformation demonstrated small excited-state structural distortion and low reorganization energy compared to the counterpart Mc-TPA with a rigid macrocycle. Consequently, Ph-TPA showed an excellent photoluminescent quantum yield (PLQY) of 92 % and a state-of-the-art external quantum efficiency (EQE) of 30.6 % at 630 nm. This work could deepen our understanding of structure-property relationships of organic luminophores and help us to rationalize the design of efficient TADF materials.
坚固的支架通常应用于热激活延迟荧光（TADF）分子中，以抑制非辐射衰减、触发快速自旋翻转并提高光出耦合效率。在此，我们首次揭示了辅助基团的柔性构象对TADF发光体光物理性质的积极影响。与具有刚性大环的对应物Mc-TPA相比，具有柔性构象的红色TADF发光体Ph-TPA表现出较小的激发态结构畸变和较低的重组能。因此，Ph-TPA在630 nm处表现出92%的优异光致发光量子产率（PLQY）和30.6%的先进外量子效率（EQE）。这项工作可以加深我们对有机发光体结构-性质关系的理解，并帮助我们合理设计高效的TADF材料。
