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Molecular Design of Non‐doped OLEDs Based on a Twisted Heptagonal Acceptor: A Delicate Balance between Rigidity and Rotatability
Author(s) -
Huang Zhenmei,
Bin Zhengyang,
Su Rongchuan,
Yang Feng,
Lan Jingbo,
You Jingsong
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201915397
Subject(s) - oled , intramolecular force , intermolecular force , stacking , quantum yield , quantum efficiency , photochemistry , acceptor , electroluminescence , materials science , chemistry , optoelectronics , fluorescence , nanotechnology , molecule , stereochemistry , organic chemistry , physics , layer (electronics) , quantum mechanics , condensed matter physics
The development of efficient non‐doped organic light‐emitting diodes (OLEDs) is highly desired but very challenging because of a severe aggregation‐caused quenching effect. Herein, we present a heptagonal diimide acceptor (BPI), which can restrict excessive intramolecular rotation and inhibit close intermolecular π–π stacking due to well‐balanced rigidity and rotatability of heptagonal structure. The BPI‐based luminogen ( DMAC‐BPI ) shows significant aggregation‐induced delayed florescence with an extremely high photoluminescence quantum yield (95.8 %) of the neat film, and the corresponding non‐doped OLEDs exhibit outstanding electroluminescence performance with maximum external quantum efficiency as high as 24.7 % and remarkably low efficiency roll‐off as low as 1.0 % at 1000 cd m −2 , which represents the state‐of‐the‐art performance for non‐doped OLEDs. In addition, the synthetic route to DMAC‐BPI is greatly streamlined and simplified through oxidative Ar−H/Ar−H homo‐coupling reaction.