Affiliation:
1. Shenzhen Key Laboratory of New Information Display and Storage Materials College of Materials Science and Engineering Shenzhen University Shenzhen 518055 P. R. China
2. College of Chemical Engineering Zhejiang University of Technology Hangzhou 310014 P. R. China
Abstract
AbstractAchieving high efficiency and low efficiency roll‐off simultaneously is of great significance for further application of thermally activated delayed fluorescent (TADF) emitters. A balance between radiative decay and reversed intersystem crossing must be carefully established. Herein, we propose a qunolino‐acridine (QAc) donor composing two acridine with both planar (pAc) and bended (bAc) geometries. Combining with triazine, a TADF emitter QAc‐TRZ is assembled. The pAc provides a well interaction with triazine which ensures a decent TADF behavior, while the bAc offers a delocalization of highest occupied molecular orbital (HOMO) which guarantees an enhancement of radiative decay. Remarkably, QAc‐TRZ enables a highly efficient organic light emitting diode (OLED) with maximum external quantum efficiency (EQE) of 37.3 %. More importantly, the efficiencies under 100/1000 cd m−2stay 36.3 % and 31.7 %, respectively, and remain 21.5 % even under 10 000 cd m−2.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Guangdong Province