Face‐to‐Face Orientation of Quasiplanar Donor and Acceptor Enables Highly Efficient Intramolecular Exciplex Fluorescence

Autor: Teng Teng, Jinfan Xiong, Chuluo Yang, Chi-Ming Che, Chao Wu, Kai Li, Weiqiang Liu, Gang Cheng
Rok vydání: 2020
Předmět:
Zdroj: Angewandte Chemie International Edition. 60:3994-3998
ISSN: 1521-3773
1433-7851
Popis: Intramolecular through-space charge-transfer (TSCT) excited states have been exploited for developing thermally activated delayed fluorescence (TADF) emitters, but the tuning of excited state dynamics by conformational engineering remains sparse. Designed here is a series of TSCT emitters with precisely controlled alignment of the donor and acceptor segments. With increasing intramolecular π-π interactions, the radiative decay rate of the lowest singlet excited state (S1 ) progressively increased together with a suppression of nonradiative decay, leading to significantly enhanced photoluminescence quantum yields of up to 0.99 in doped thin films. A high-efficiency electroluminescence device, with a maximum external quantum efficiency (EQE) of 23.96 %, was achieved and maintains >20 % at a brightness of 1000 cd m-2 . This work sheds light on the importance of conformation control for achieving high-efficiency intramolecular exciplex emitters.
Databáze: OpenAIRE
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