题目：

Enhancing Reverse Intersystem Crossing of Multiple Resonance Type Thermally Activated Delayed Fluorescence Emitter by Introducing Spatial Perturbation

作者：

Xin Xiong¹, Jia-Qi Li¹, Ting-Feng Chen¹, Xiao-Chun Fan¹, Ying-Chun Cheng¹, Hui Wang¹, Feng Huang¹, Hao Wu¹, Jia Yu¹, Xian-Kai Chen^1,2*, Kai Wang^1,3* and Xiao-Hong Zhang^1,2*

单位：

¹Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, 199 Ren-Ai Road, Suzhou 215123, China

²Jiangsu Key Laboratory of Advanced Negative Carbon Technologies Soochow University Suzhou, Jiangsu 215123, P. R. China

³Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices Soochow University Suzhou, Jiangsu 215123, P. R. China

摘要：

For multiple resonance (MR) type thermally activated delayed fluorescence (TADF) emitters, electron cloud distributions of their π-conjugated planes are crucial for determining their eventual performance. Currently, modulation attempts of MR-TADF emitters are mainly inside the π-conjugated planes. Possible out-of-plane interactions may also significantly impact the photophysical properties, but the exploration is quite limited. Here, a novel concept of using out-of-plane (e.g., π–π and lone pair-π) interactions to introduce spatial perturbation (SPPT) to improve TADF performance is proposed. Two newly developed MR-TADF emitters, namely,o-BNPOandBNPO, which both consist of a popular MR framework,DtBuCzB, and diphenylphosphine oxide (DPPO), are compared in depth. In particular, foro-BNPO, evident π–π interaction is observed between one side of theDtBuCzBπ-conjugated plane and a phenyl ring fromDPPO, and lone pair-π interaction with the oxygen atom fromDPPOis noticed on the other side, resulting in significantly accelerated reverse intersystem crossing and better TADF without sacrificing narrowband emission features. Ultimately, in organic light-emitting diodes with sensitizer-free emitting layers, both emitters achieve similar narrowband emissions, while theo-BNPO-based device demonstrates a much higher external quantum efficiency of 36% and milder efficiency roll-off.

影响因子：

19.924

分区情况：

一区

链接：

https://onlinelibrary.wiley.com/doi/full/10.1002/adfm.202313726