AUTHOR=Li Huanhuan , Zhi Yibin , Dai Yizhong , Jiang Yunbo , Yang Qingqing , Li Mingguang , Li Ping , Tao Ye , Li Hui , Huang Wei , Chen Runfeng 

TITLE=Asymmetric Thermally Activated Delayed Fluorescence Materials With Aggregation-Induced Emission for High-Efficiency Organic Light-Emitting Diodes

JOURNAL=Frontiers in Chemistry

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2020.00049

DOI=10.3389/fchem.2020.00049

ISSN=2296-2646

ABSTRACT=<p>The exploitation of thermally activated delayed fluorescence (TADF) emitters with aggregation-induced emission is highly prerequisite for the construction of highly efficient electroluminescent devices in materials science. Herein, two asymmetric TADF emitters of <bold>SFCOCz</bold> and <bold>SFCODPAC</bold> with charming aggregation-induced emission are expediently designed and prepared based on highly twisted strong electron-withdrawing acceptor (A) of sulfurafluorene (<bold>SF</bold>)-modified ketone (<bold>CO</bold>) and arylamine donor (D) in D<sub>1</sub>−A–D<sub>2</sub> architecture by simple synthetic procedure in high yields. High photoluminescence quantum yields up to 73% and small singlet–triplet splitting of 0.03 eV; short exciton lifetimes are obtained in the resultant molecules. Strikingly, efficient non-doped and doped TADF organic light-emitting diodes (OLEDs) facilitated by these emitters show high luminance of 5,598 and 11,595 cd m<sup>−2</sup>, current efficiencies (CEs) of 16.8 and 35.6 cd/A, power efficiencies (PEs) of 9.1 and 29.8 lm/W, and external quantum efficiencies (EQEs) of 7.5 and 15.9%, respectively. This work furnishes a concrete instance in exploring efficient TADF emitter, which is highly conducive and encouraging in stimulating the development of TADF OLEDs with high brightness and excellent efficiencies simultaneously.</p>