Chem: Enhancing multi-resonance thermally activated delayed fluorescence emission via through-space heavy-atom effect

Title：

Enhancing multi-resonance thermally activated delayed fluorescence emission via through-space heavy-atom effect

Authors：

Qi Zheng¹, Yang-Kun Qu¹, Peng Zuo¹, Hai-Tian Yuan¹, Yue-Jian Yang¹, Yu-Chen Qiu¹, Liang-Sheng Liao^1,2, Dong-Ying Zhou¹* and Zuo-Quan Jiang¹*

Institutions：

¹Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China.

²Macao Institute of Materials Science and Engineering Macau University of Science and Technology, Taipa, Macau SAR 999078, P. R. China.

Abstract：

Recent research has focused on the heavy-atom effect in organic luminescent materials, especially in multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters. Traditional strategies involve directly conjugating heavy atoms to the chromophore, which often broadens the emission spectrum. This study explores an unconventional approach using the through-space heavy-atom effect, positioning heavy-atom moieties with nonconjugated short-range interaction with the chromophore. This method successfully demonstrates the intramolecular external heavy-atom effect proposed in the 1970s in cutting-edge high-efficiency emissive materials. Comparative analysis of these emitters confirms the spatial heavy-atom effect, maintaining the spectroscopic properties of MR chromophore while significantly improving external quantum efficiency in organic light-emitting diodes (OLEDs). These emitters also mitigate efficiency roll-off, showcasing the potential of spatial interactions to enhance MR-TADF materials for OLED applications.

IF：

19.1

Link：

https://doi.org/10.1016/j.chempr.2024.10.020