1. Multi‐Layer π‐Stacked Molecules as Efficient Thermally Activated Delayed Fluorescence Emitters.
- Author
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Wang, Xue‐Qi, Yang, Sheng‐Yi, Tian, Qi‐Sheng, Zhong, Cheng, Qu, Yang‐Kun, Yu, You‐Jun, Jiang, Zuo‐Quan, and Liao, Liang‐Sheng
- Subjects
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DELAYED fluorescence , *CHARGE transfer , *MOLECULES , *QUANTUM efficiency - Abstract
Multi‐layer π‐stacked emitters based on spatially confined donor/acceptor/donor (D/A/D) patterns have been developed to achieve high‐efficiency thermally activated delayed fluorescence (TADF). In this case, dual donor moieties and a single acceptor moiety are introduced to form two three‐dimensional (3D) emitters, DM‐BD1 and DM‐BD2, which rely on spatial charge transfer (CT). Owing to the enforced face‐to‐face D/A/D pattern, effective CT interactions are realized, which lead to high photoluminescence quantum yields (PLQYs) of 94.2 % and 92.8 % for the two molecules, respectively. The resulting emitters exhibit small singlet–triplet energy splitting (ΔEST) and fast reverse intersystem crossing (RISC) processes. Maximum external quantum efficiencies (EQEs) of 28.0 % and 26.6 % were realized for devices based on DM‐BD1 and DM‐BD2, respectively, which are higher than those of their D/A‐type analogues. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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