Enhanced Electroluminescence Based on a π-Conjugated Heptazine Derivative by Exploiting Thermally Activated Delayed Fluorescence
Heptazine derivatives have attracted much attention over the past decade by virtue of intriguing optical, photocatalytic as well as electronic properties in the fields of hydrogen evolution, organic optoelectronic technologies and so forth. Here, we report a simple π-conjugated heptazine derivative...
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doaj-d5a21a802732445aa927f280e6ecdef12021-05-13T04:43:08ZengFrontiers Media S.A.Frontiers in Chemistry2296-26462021-05-01910.3389/fchem.2021.693813693813Enhanced Electroluminescence Based on a π-Conjugated Heptazine Derivative by Exploiting Thermally Activated Delayed FluorescenceJie Li0Heqi Gong1Jincheng Zhang2Shiyi Zhou3Li Tao4Lihua Jiang5Qiang Guo6College of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu, ChinaCollege of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu, ChinaCollege of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu, ChinaCollege of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu, ChinaCollege of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu, ChinaCollege of Electrical Engineering & New Energy, Hubei Provincial Engineering Technology Research Center for Power Transmission Line, China Three Gorges University, Yichang, ChinaCollege of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu, ChinaHeptazine derivatives have attracted much attention over the past decade by virtue of intriguing optical, photocatalytic as well as electronic properties in the fields of hydrogen evolution, organic optoelectronic technologies and so forth. Here, we report a simple π-conjugated heptazine derivative (HAP-3DF) possessing an n→π* transition character which exhibits enhanced electroluminescence by exploiting thermally activated delayed fluorescence (TADF). Green-emitting HAP-3DF shows relatively low photoluminescence quantum efficiencies (Φp) of 0.08 in toluene and 0.16 in doped film with bis(2-(diphenylphosphino)phenyl) ether oxide (DPEPO) as the matrix. Interestingly, the organic light-emitting diode (OLED) incorporating 8 wt% HAP-3DF:DPEPO as an emitting layer achieved a high external quantum efficiency (EQE) of 3.0% in view of the fairly low Φp of 0.16, indicating the presence of TADF stemming from n→π* transitions. As the matrix changing from DPEPO to 1,3-di (9H-carbazol-9-yl)benzene (mCP), a much higher Φp of 0.56 was found in doped film accompanying yellow emission. More importantly, enhanced electroluminescence was observed from the OLED containing 8 wt% HAP-3DF:mCP as an emitting layer, and a rather high EQE of 10.8% along with a low roll-off was realized, which should be ascribed to the TADF process deriving from exciplex formation.https://www.frontiersin.org/articles/10.3389/fchem.2021.693813/fullelectroluminescenceheptazinethermally activated delayed fluorescenceorganic light-emitting diodeexciplex |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Jie Li Heqi Gong Jincheng Zhang Shiyi Zhou Li Tao Lihua Jiang Qiang Guo |
spellingShingle |
Jie Li Heqi Gong Jincheng Zhang Shiyi Zhou Li Tao Lihua Jiang Qiang Guo Enhanced Electroluminescence Based on a π-Conjugated Heptazine Derivative by Exploiting Thermally Activated Delayed Fluorescence Frontiers in Chemistry electroluminescence heptazine thermally activated delayed fluorescence organic light-emitting diode exciplex |
author_facet |
Jie Li Heqi Gong Jincheng Zhang Shiyi Zhou Li Tao Lihua Jiang Qiang Guo |
author_sort |
Jie Li |
title |
Enhanced Electroluminescence Based on a π-Conjugated Heptazine Derivative by Exploiting Thermally Activated Delayed Fluorescence |
title_short |
Enhanced Electroluminescence Based on a π-Conjugated Heptazine Derivative by Exploiting Thermally Activated Delayed Fluorescence |
title_full |
Enhanced Electroluminescence Based on a π-Conjugated Heptazine Derivative by Exploiting Thermally Activated Delayed Fluorescence |
title_fullStr |
Enhanced Electroluminescence Based on a π-Conjugated Heptazine Derivative by Exploiting Thermally Activated Delayed Fluorescence |
title_full_unstemmed |
Enhanced Electroluminescence Based on a π-Conjugated Heptazine Derivative by Exploiting Thermally Activated Delayed Fluorescence |
title_sort |
enhanced electroluminescence based on a π-conjugated heptazine derivative by exploiting thermally activated delayed fluorescence |
publisher |
Frontiers Media S.A. |
series |
Frontiers in Chemistry |
issn |
2296-2646 |
publishDate |
2021-05-01 |
description |
Heptazine derivatives have attracted much attention over the past decade by virtue of intriguing optical, photocatalytic as well as electronic properties in the fields of hydrogen evolution, organic optoelectronic technologies and so forth. Here, we report a simple π-conjugated heptazine derivative (HAP-3DF) possessing an n→π* transition character which exhibits enhanced electroluminescence by exploiting thermally activated delayed fluorescence (TADF). Green-emitting HAP-3DF shows relatively low photoluminescence quantum efficiencies (Φp) of 0.08 in toluene and 0.16 in doped film with bis(2-(diphenylphosphino)phenyl) ether oxide (DPEPO) as the matrix. Interestingly, the organic light-emitting diode (OLED) incorporating 8 wt% HAP-3DF:DPEPO as an emitting layer achieved a high external quantum efficiency (EQE) of 3.0% in view of the fairly low Φp of 0.16, indicating the presence of TADF stemming from n→π* transitions. As the matrix changing from DPEPO to 1,3-di (9H-carbazol-9-yl)benzene (mCP), a much higher Φp of 0.56 was found in doped film accompanying yellow emission. More importantly, enhanced electroluminescence was observed from the OLED containing 8 wt% HAP-3DF:mCP as an emitting layer, and a rather high EQE of 10.8% along with a low roll-off was realized, which should be ascribed to the TADF process deriving from exciplex formation. |
topic |
electroluminescence heptazine thermally activated delayed fluorescence organic light-emitting diode exciplex |
url |
https://www.frontiersin.org/articles/10.3389/fchem.2021.693813/full |
work_keys_str_mv |
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