TY - JOUR
T1 - The role of fluorine-substitution on the π-bridge in constructing effective thermally activated delayed fluorescence molecules
AU - Li, Yun
AU - Liang, Jiao Jiao
AU - Li, Hong Cheng
AU - Cui, Lin Song
AU - Fung, Man Keung
AU - Barlow, Stephen
AU - Marder, Seth R.
AU - Adachi, Chihaya
AU - Jiang, Zuo Quan
AU - Liao, Liang Sheng
N1 - Funding Information:
We acknowledge financial support from the National Natural Science Foundation of China (Grant No. 61575136 and 21572152) and the National Key R&D Program of China (Grant No. 2016YFB0400700). This project is also funded by the Collaborative Innovation Center of Suzhou Nano Science and Technology (Nano-CIC), by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), by the ‘‘111’’ Project of the State Administration of Foreign Experts Affairs of China, and by the Yunnan Provincial Research Funds on College-Enterprise Collaboration (No. 2015IB016). We also thank Yi Yuan and Dr Yadong Zhang for helpful discussions in design and analysis of the experiment.
Publisher Copyright:
© 2018 The Royal Society of Chemistry.
PY - 2018
Y1 - 2018
N2 - Two thermally activated delayed fluorescence (TADF) emitters 9′-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-fluorophenyl)-9′H-9,3′:6′,9′′-tercarbazole (TCTZ-F) and 9′-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2,6-difluorophenyl)-9′H-9,3′:6′,9′′-tercarbazole (TCTZ-2F) were synthesized and compared to the previously reported molecule 9′-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-9′H-9,3′:6′,9′′-tercarbazole (TCTZ) to explore the possible effects of the fluorine atom(s) on the molecular conformation, electronic coupling between the donor and acceptor groups, and consequently the photophysical behavior of the emitters. Specifically, the TCTZ-F molecule was calculated to have a smaller dihedral angle than TCTZ-2F and a smaller S1-T1 gap than TCTZ, which led it to have the highest photoluminescence quantum yield (PLQY) among this series of compounds. An OLED fabricated with TCTZ-F as the emitter achieved the highest external quantum efficiencies (22.5%) of this series, indicating that fluorination can play a useful role in TADF emitters.
AB - Two thermally activated delayed fluorescence (TADF) emitters 9′-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-fluorophenyl)-9′H-9,3′:6′,9′′-tercarbazole (TCTZ-F) and 9′-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)-2,6-difluorophenyl)-9′H-9,3′:6′,9′′-tercarbazole (TCTZ-2F) were synthesized and compared to the previously reported molecule 9′-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-9′H-9,3′:6′,9′′-tercarbazole (TCTZ) to explore the possible effects of the fluorine atom(s) on the molecular conformation, electronic coupling between the donor and acceptor groups, and consequently the photophysical behavior of the emitters. Specifically, the TCTZ-F molecule was calculated to have a smaller dihedral angle than TCTZ-2F and a smaller S1-T1 gap than TCTZ, which led it to have the highest photoluminescence quantum yield (PLQY) among this series of compounds. An OLED fabricated with TCTZ-F as the emitter achieved the highest external quantum efficiencies (22.5%) of this series, indicating that fluorination can play a useful role in TADF emitters.
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U2 - 10.1039/c8tc01158c
DO - 10.1039/c8tc01158c
M3 - Article
AN - SCOPUS:85047558949
VL - 6
SP - 5536
EP - 5541
JO - Journal of Materials Chemistry C
JF - Journal of Materials Chemistry C
SN - 2050-7526
IS - 20
ER -