Zhao Haisong, Zhao Jinyang, Hua Lei, Zhao Zhennan, Liu Yuchao, Zhang Xinwen, Yan Shouke, Ren Zhongjie
State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
School of Materials Science & Engineering, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou, 213164, China.
Small. 2025 Aug;21(33):e2503089. doi: 10.1002/smll.202503089. Epub 2025 Jun 25.
High-efficiency thermally activated delayed fluorescence (TADF) polymer is one of the excellent choices for solution-processable electroluminescent devices due to their 100% theoretical exciton utilization. Herein, different from the previous TADF copolymers with carbon-carbon main-chains, TADF polymers with silicon-oxygen main-chains are innovatively prepared by easily combing polysiloxanes with TADF and host units. The flexible polysiloxane chains are rigidified by the cation-π interaction between the electropositive silicon atoms and TADF units, resulting in reduced vibrational relaxation and thus the narrow full width at half maximum and high photoluminescence quantum efficiency. Consequently, solution-processed non-doped OLEDs based on the prepared homopolysiloxane PSiBPA reach a maximum external quantum efficiency (EQE) of 27% and EQE of 20% at 500 cd m, which keeps at the forefront of non-doped polymer devices to date. Noteworthily, PSiBPA is the only high-efficiency homopolymer reported so far. Furthermore, PSiBPA presents outstanding mechanical properties.Thus, bendable OLEDs that demonstrate the maximum brightness and EQE barely starting attenuation with a bending radius of 2 mm are showcased. Moreover, the maximum brightness and EQE can still maintain 60% after 50 bends. The design strategy develops a novel approach to optimizing the properties of TADF polymers via cation-π interactions for constructing high-efficiency non-doped and flexible OLEDs.
高效热激活延迟荧光（TADF）聚合物因其100%的理论激子利用率，是可溶液加工电致发光器件的优秀选择之一。在此，与先前具有碳 - 碳主链的TADF共聚物不同，具有硅 - 氧主链的TADF聚合物通过将聚硅氧烷与TADF和主体单元轻松结合而创新制备。柔性聚硅氧烷链通过正电硅原子与TADF单元之间的阳离子 - π相互作用而刚性化，导致振动弛豫减少，从而半高宽变窄且光致发光量子效率提高。因此，基于所制备的均聚硅氧烷PSiBPA的溶液加工非掺杂有机发光二极管（OLED）在500 cd m时达到最大外量子效率（EQE）为27%，在500 cd m时EQE为20%，这使其至今仍处于非掺杂聚合物器件的前沿。值得注意的是，PSiBPA是迄今为止报道的唯一一种高效均聚物。此外，PSiBPA具有出色的机械性能。因此，展示了可弯曲的OLED，其在弯曲半径为2 mm时，最大亮度和EQE几乎不开始衰减。而且，在50次弯曲后，最大亮度和EQE仍可保持60%。该设计策略通过阳离子 - π相互作用开发了一种优化TADF聚合物性能的新方法，用于构建高效非掺杂和柔性OLED。
