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Exciton Up-Conversion by Well-Distributed Carbon Quantum Dots in Luminescent Materials for an Efficient Organic Light-Emitting Diode
In this work, we proposed an efficient and straightforward up-conversion process to enhance the external quantum efficiency in a red-emission organic light-emitting diode (OLED). The carbon quantum dots in the luminescent materials initiated the up-conversion by doping the (6,6)-phenyl-C61-butyric a...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2022
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9000295/ https://www.ncbi.nlm.nih.gov/pubmed/35407292 http://dx.doi.org/10.3390/nano12071174 |
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author | Pei, Zingway Wei, Han-Yun Liu, Yi-Chun |
author_facet | Pei, Zingway Wei, Han-Yun Liu, Yi-Chun |
author_sort | Pei, Zingway |
collection | PubMed |
description | In this work, we proposed an efficient and straightforward up-conversion process to enhance the external quantum efficiency in a red-emission organic light-emitting diode (OLED). The carbon quantum dots in the luminescent materials initiated the up-conversion by doping the (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) in an amount of 0.001 wt. %, and the external quantum efficiency (EQE) increased from approximately 80% to 9.27% without spectrum change. The time-resolved photoluminescence was applied to understand the mechanism of EQE enhancement in the PCBM-doped OLED. Two decay-time constants fit the TRPL. After PCBM doping, the extended PL intensity indicated increased time constants. The time constants increased from 1.06 and 4.02 ns of the reference sample to 3.48 and 11.29 ns of the PCBM-doped material, respectively. The nonradiative energy transfer (NRET) mechanism was proposed responsible for the decay-time enhancement. The excitons in the PCBM, either by excitation or injection, will transfer to the phosphorescent material nonradiatively. As the PCBM has lower energy levels than the luminous material for electrons, the backward exciton transfer is a kind of up-conversion. With the increased amounts of excitons in the luminescent material, the luminescent external quantum efficiency and the decay-time increased. This up-conversion method is not limited to the red-emission OLED; it could also be applied to blue or green emission. |
format | Online Article Text |
id | pubmed-9000295 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2022 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-90002952022-04-12 Exciton Up-Conversion by Well-Distributed Carbon Quantum Dots in Luminescent Materials for an Efficient Organic Light-Emitting Diode Pei, Zingway Wei, Han-Yun Liu, Yi-Chun Nanomaterials (Basel) Article In this work, we proposed an efficient and straightforward up-conversion process to enhance the external quantum efficiency in a red-emission organic light-emitting diode (OLED). The carbon quantum dots in the luminescent materials initiated the up-conversion by doping the (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) in an amount of 0.001 wt. %, and the external quantum efficiency (EQE) increased from approximately 80% to 9.27% without spectrum change. The time-resolved photoluminescence was applied to understand the mechanism of EQE enhancement in the PCBM-doped OLED. Two decay-time constants fit the TRPL. After PCBM doping, the extended PL intensity indicated increased time constants. The time constants increased from 1.06 and 4.02 ns of the reference sample to 3.48 and 11.29 ns of the PCBM-doped material, respectively. The nonradiative energy transfer (NRET) mechanism was proposed responsible for the decay-time enhancement. The excitons in the PCBM, either by excitation or injection, will transfer to the phosphorescent material nonradiatively. As the PCBM has lower energy levels than the luminous material for electrons, the backward exciton transfer is a kind of up-conversion. With the increased amounts of excitons in the luminescent material, the luminescent external quantum efficiency and the decay-time increased. This up-conversion method is not limited to the red-emission OLED; it could also be applied to blue or green emission. MDPI 2022-04-01 /pmc/articles/PMC9000295/ /pubmed/35407292 http://dx.doi.org/10.3390/nano12071174 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Pei, Zingway Wei, Han-Yun Liu, Yi-Chun Exciton Up-Conversion by Well-Distributed Carbon Quantum Dots in Luminescent Materials for an Efficient Organic Light-Emitting Diode |
title | Exciton Up-Conversion by Well-Distributed Carbon Quantum Dots in Luminescent Materials for an Efficient Organic Light-Emitting Diode |
title_full | Exciton Up-Conversion by Well-Distributed Carbon Quantum Dots in Luminescent Materials for an Efficient Organic Light-Emitting Diode |
title_fullStr | Exciton Up-Conversion by Well-Distributed Carbon Quantum Dots in Luminescent Materials for an Efficient Organic Light-Emitting Diode |
title_full_unstemmed | Exciton Up-Conversion by Well-Distributed Carbon Quantum Dots in Luminescent Materials for an Efficient Organic Light-Emitting Diode |
title_short | Exciton Up-Conversion by Well-Distributed Carbon Quantum Dots in Luminescent Materials for an Efficient Organic Light-Emitting Diode |
title_sort | exciton up-conversion by well-distributed carbon quantum dots in luminescent materials for an efficient organic light-emitting diode |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9000295/ https://www.ncbi.nlm.nih.gov/pubmed/35407292 http://dx.doi.org/10.3390/nano12071174 |
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