American Chemical Society
jz2c01917_si_001.pdf (12.16 MB)

Tuning Hybridized Local and Charge-Transfer Mixing for Efficient Hot-Exciton Emission with Improved Color Purity

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journal contribution
posted on 2022-07-15, 16:09 authored by Yaxin Wang, Zilong Guo, Yixuan Gao, Yiran Tian, Yingyi Deng, Xiaonan Ma, Wensheng Yang
Delayed fluorescence (DF) emitters with high color purity are of high interest for applications in high-resolution displays. However, the charge transfer required by high emitting efficiency usually conflicts with the expected color purity. In this work, we investigated the S1/S0 conformational relaxation, spin–orbital coupling (SOC), and vibronic coupling of hot-exciton emitters while hybrid local and charge transfer (HLCT) state tuning was achieved by a structural meta-effect. The meta-linkage leads to suppressed S1/S0 conformational relaxation and weakened vibronic coupling, while the unsacrificed emitting efficiency is largely ensured by multiple rISC channels (Tn → Sm) with thermally accessible triplet–singlet energy gap (ΔEST) and effective SOC. We demonstrated that the unique excited-state mechanism provides opportunities to improve the emitting color purity of hot-exciton emitters without sacrificing emitting efficiency by HLCT state tuning with simple chemical structural modification, for which hot-exciton emitters might play a more important role for high-resolution organic light-emitting diode displays.