Premium
Modulating the Electron‐Donating Ability of Acridine Donor Units for Orange–Red Thermally Activated Delayed Fluorescence Emitters
Author(s) -
Chen Tianheng,
Lu ChenHan,
Chen Zhanxiang,
Gong Xu,
Wu ChungChih,
Yang Chuluo
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202004719
Subject(s) - acridine orange , moiety , fluorescence , photochemistry , benzothiophene , orange (colour) , electron donor , oled , isoquinoline , chemistry , acridine , toluene , acceptor , common emitter , quantum efficiency , materials science , stereochemistry , optoelectronics , organic chemistry , apoptosis , thiophene , catalysis , optics , biochemistry , physics , food science , layer (electronics) , condensed matter physics
The development of thermally activated delayed fluorescence (TADF) emitters with orange–red emission still lags behind that of their blue, green, and yellow counterparts. Recent research to address this problem mainly focused on developing new acceptor units. There were few donor units designed especially for orange–red emitters. Herein, with benzothiophene fused to a diphenylacridine donor unit, a new donor moiety, namely, 5,5‐diphenyl‐5,13‐dihydrobenzo[4,5]thieno[3,2‐ c ]acridine (BTDPAc), was designed and synthesized. Benefiting from the strong electron‐donating ability of the new donor moiety, a new TADF emitter, 2‐[4′‐( tert ‐butyl)(1,1′‐biphenyl)‐4‐yl]‐6‐[5,5‐diphenylbenzo[4,5]thieno[3,2‐ c ]acridin‐13(5 H )‐yl]‐1 H ‐benzo[ de ]isoquinoline‐1,3(2 H )‐dione (BTDPAc‐PhNAI), shows an orange–red emission with a maximum at 610 nm in dilute toluene solution. Also, with the help of the diphenyl rings of the donor unit, high photoluminescence quantum yields were achieved for BTDPAc‐PhNAI over a wide concentration range. Consequently, an orange–red organic light‐emitting diode based on BTDPAc‐PhNAI achieved a high external quantum efficiency of nearly 20 %, which was comparable to state‐of‐the‐art device performances with similar emission spectra.