Cargando…

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...

Descripción completa

Detalles Bibliográficos
Autores principales: Iwasaki, Yukiko, Fukagawa, Hirohiko, Shimizu, Takahisa
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
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
_version_ 1783397069125320704
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
work_keys_str_mv AT iwasakiyukiko effectofhostmoietiesonthephosphorescentspectrumofgreenplatinumcomplex
AT fukagawahirohiko effectofhostmoietiesonthephosphorescentspectrumofgreenplatinumcomplex
AT shimizutakahisa effectofhostmoietiesonthephosphorescentspectrumofgreenplatinumcomplex