1. Direct Population of Triplet States for Efficient Organic Afterglow through the Intra/Intermolecular Heavy-Atom Effect
- Author
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Jie Yuan, Yongrong Wang, Binbin Zhou, Wenjing Xie, Botao Zheng, Jingyu Zhang, Ping Li, Tian Yu, Yuanyuan Qi, Ye Tao, and Runfeng Chen
- Subjects
organic afterglow ,S0→T1 absorption ,heavy atom effect ,visible-light excitable ,pattern encryption ,Organic chemistry ,QD241-441 - Abstract
Organic afterglow is a fascinating phenomenon with exceptional applications. However, it encounters challenges such as low intensity and efficiency, and typically requires UV-light excitation and facile intersystem crossing (ISC) due to its spin-forbidden nature. Here, we develop a novel strategy that bypasses the conventional ISC pathway by promoting singlet-triplet transition through the synergistic effects of the intra/intermolecular heavy-atom effect in aromatic crystals, enabling the direct population of triplet excited states from the ground state. The resulting materials exhibit a bright organic afterglow with a remarkably enhanced quantum efficiency of up to 5.81%, and a significantly increased organic afterglow lifetime of up to 157 microseconds under visible light. Moreover, given the high-efficiency visible-light excitable organic afterglow emission, the potential application is demonstrated in lifetime-resolved, color-encoded, and excitation wavelength-dependent pattern encryption. This work demonstrates the importance of the direct population method in enhancing the organic afterglow performance and red-shifting the excitation wavelength, and provides crucial insights for advancing organic optoelectronic technologies that involve triplet states.
- Published
- 2024
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