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Optimizing Charge Transfer and Out‐Coupling of A Quasi‐Planar Deep‐Red TADF Emitter: towards Rec.2020 Gamut and External Quantum Efficiency beyond 30 %
Author(s) -
Li Zhe,
Yang Dezhi,
Han Chunmiao,
Zhao Bingjie,
Wang Huiqin,
Man Yi,
Ma Peng,
Chang Peng,
Ma Dongge,
Xu Hui
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202103070
Subject(s) - quantum yield , triphenylamine , quantum efficiency , photoluminescence , materials science , oled , optoelectronics , common emitter , color rendering index , gamut , acceptor , electroluminescence , planar , fluorescence , light emitting diode , optics , nanotechnology , physics , computer graphics (images) , layer (electronics) , condensed matter physics , computer science
Herein, we report a deep‐red TADF emitter p CNQ–TPA , composed of quinoxaline‐5,8‐dicarbonitrile ( p CNQ) acceptor and triphenylamine (TPA) donor. p CNQ–TPA supported its OLED with desired CIE coordinates of (0.69, 0.31) and the record maximum external quantum efficiency of 30.3 %, which is the best red TADF diode with Rec.2020 gamut for UHDTV. It is showed that through tuning p CNQ–TPA doping concentration, intra‐ and inter‐molecular charge transfer are balanced to synchronously improve emission color saturation and TADF radiation, and remedy aggregation‐induced quenching, rendering photoluminescence quantum yield (PLQY) reaching 90 % for deep‐red emission peaked at ≈690 nm. Quasi‐planar structure further endows p CNQ–TPA with an improved horizontal ratio of emitting dipole orientation, which increases light out‐coupling ratio to 0.34 for achieving the state‐of‐the‐art device efficiencies.