Xie Feng-Ming, Li Hao-Ze, Zhang Kai, Shen Yang, Zhao Xin, Li Yan-Qing, Tang Jian-Xin
Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
School of Physics and Electronic Science, Ministry of Education Nanophotonics & Advanced Instrument Engineering Research Center, East China Normal University, Shanghai, 200062, P. R. China.
Angew Chem Int Ed Engl. 2022 Dec 5;61(49):e202213823. doi: 10.1002/anie.202213823. Epub 2022 Nov 9.
Organic materials featuring intramolecular through-space charge transfer (TSCT) excited states are advantageous for efficient thermally activated delayed fluorescence (TADF), although the realization of multiple TSCT systems remains challenging. Herein, a rigid molecule with a three-dimensional dislocated sandwich acceptor-donor-acceptor configuration has been developed by a linking biphenazine (2PXZ) donor and 2,4,6-triphenyl-1,3,5-triazine (TRZ) acceptor through the twin-locking of two spiro-fluorene bridges. The twin-locking construction with multiple TSCT effects suppresses the intramolecular rotations of various segments in 2PXZ-2TRZ, leading to a small singlet-triplet energy difference, a fast reverse intersystem crossing process, and high photoluminescence quantum yield. This material simultaneously possesses the capabilities of TADF and aggregation-induced emission. The device employing 2PXZ-2TRZ as a dopant displays an optimal external quantum efficiency of 27.1 % and a low efficiency roll-off.
具有分子内空间电荷转移（TSCT）激发态的有机材料有利于实现高效的热激活延迟荧光（TADF），尽管实现多个TSCT系统仍然具有挑战性。在此，通过两个螺芴桥的双锁定，将联苯并菲（2PXZ）供体和2,4,6-三苯基-1,3,5-三嗪（TRZ）受体连接起来，开发了一种具有三维错位夹心给体-受体-给体构型的刚性分子。具有多种TSCT效应的双锁定结构抑制了2PXZ-2TRZ中各个片段的分子内旋转，导致单线态-三线态能量差小、反向系间窜越过程快以及高光致发光量子产率。这种材料同时具备TADF和聚集诱导发光的能力。采用2PXZ-2TRZ作为掺杂剂的器件显示出27.1%的最佳外量子效率和低效率滚降。
