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Effect of Host Moieties on the Phosphorescent Spectrum of Green Platinum Complex
Highly efficient, operationally stable, and pure-color organic light-emitting diodes (OLEDs) are of considerable significance for developing practical wide-color-gamut displays. Further, we have demonstrated the feasibility of an efficient pure green phosphorescent OLED (PHOLED) by employing a narro...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6384832/ https://www.ncbi.nlm.nih.gov/pubmed/30696004 http://dx.doi.org/10.3390/molecules24030454 |
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author | Iwasaki, Yukiko Fukagawa, Hirohiko Shimizu, Takahisa |
author_facet | Iwasaki, Yukiko Fukagawa, Hirohiko Shimizu, Takahisa |
author_sort | Iwasaki, Yukiko |
collection | PubMed |
description | Highly efficient, operationally stable, and pure-color organic light-emitting diodes (OLEDs) are of considerable significance for developing practical wide-color-gamut displays. Further, we have demonstrated the feasibility of an efficient pure green phosphorescent OLED (PHOLED) by employing a narrow-band platinum complex and a top-emitting structure. The utilization of the thermally activated delayed fluorescence (TADF) material as the phosphorescent host is expected to serve as a promising solution for obtaining operationally stable PHOLEDs with high color purity. However, the emission spectrum of the platinum complex in the TADF host exhibits a considerably broad emission spectrum. This study investigates the cause of the spectral change by evaluating the photoluminescence spectra of the platinum complex in various hosts exhibiting different molecular structures. The triazine unit in the host material was observed to result in exciplex formation between the lowest unoccupied molecular orbital (LUMO) of the host and the highest occupied molecular orbital (HOMO) of the platinum complex. Therefore, the TADF material that sterically hinders the triazine unit is considered to be suitable to prevent both exciplex formation and spectral broadening. |
format | Online Article Text |
id | pubmed-6384832 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-63848322019-02-23 Effect of Host Moieties on the Phosphorescent Spectrum of Green Platinum Complex Iwasaki, Yukiko Fukagawa, Hirohiko Shimizu, Takahisa Molecules Article Highly efficient, operationally stable, and pure-color organic light-emitting diodes (OLEDs) are of considerable significance for developing practical wide-color-gamut displays. Further, we have demonstrated the feasibility of an efficient pure green phosphorescent OLED (PHOLED) by employing a narrow-band platinum complex and a top-emitting structure. The utilization of the thermally activated delayed fluorescence (TADF) material as the phosphorescent host is expected to serve as a promising solution for obtaining operationally stable PHOLEDs with high color purity. However, the emission spectrum of the platinum complex in the TADF host exhibits a considerably broad emission spectrum. This study investigates the cause of the spectral change by evaluating the photoluminescence spectra of the platinum complex in various hosts exhibiting different molecular structures. The triazine unit in the host material was observed to result in exciplex formation between the lowest unoccupied molecular orbital (LUMO) of the host and the highest occupied molecular orbital (HOMO) of the platinum complex. Therefore, the TADF material that sterically hinders the triazine unit is considered to be suitable to prevent both exciplex formation and spectral broadening. MDPI 2019-01-28 /pmc/articles/PMC6384832/ /pubmed/30696004 http://dx.doi.org/10.3390/molecules24030454 Text en © 2019 by the authors. 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 (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Iwasaki, Yukiko Fukagawa, Hirohiko Shimizu, Takahisa Effect of Host Moieties on the Phosphorescent Spectrum of Green Platinum Complex |
title | Effect of Host Moieties on the Phosphorescent Spectrum of Green Platinum Complex |
title_full | Effect of Host Moieties on the Phosphorescent Spectrum of Green Platinum Complex |
title_fullStr | Effect of Host Moieties on the Phosphorescent Spectrum of Green Platinum Complex |
title_full_unstemmed | Effect of Host Moieties on the Phosphorescent Spectrum of Green Platinum Complex |
title_short | Effect of Host Moieties on the Phosphorescent Spectrum of Green Platinum Complex |
title_sort | effect of host moieties on the phosphorescent spectrum of green platinum complex |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6384832/ https://www.ncbi.nlm.nih.gov/pubmed/30696004 http://dx.doi.org/10.3390/molecules24030454 |
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