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Effects of the Thickness of N,N′-diphenyl-N,N′-di(m-tolyl)-benzidine on the Electro-Optical Characteristics of Organic Light-Emitting Diodes

We examined the electro-optical characteristics of organic light emitting diodes according to the N,N′-diphenyl-N,N′-di(m-tolyl)-benzidine (TPD) thicknesses. The thicknesses of TPD were varied from 5 nm to 50 nm. The current density of the device with a TPD thickness of 5 nm was 8.94 times higher th...

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Autores principales: Park, Sang-Geon, Lee, Won Jae, Song, Min Jong, Shin, Johngeon, Kim, Tae Wan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6471192/
https://www.ncbi.nlm.nih.gov/pubmed/30909501
http://dx.doi.org/10.3390/ma12060966
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author Park, Sang-Geon
Lee, Won Jae
Song, Min Jong
Shin, Johngeon
Kim, Tae Wan
author_facet Park, Sang-Geon
Lee, Won Jae
Song, Min Jong
Shin, Johngeon
Kim, Tae Wan
author_sort Park, Sang-Geon
collection PubMed
description We examined the electro-optical characteristics of organic light emitting diodes according to the N,N′-diphenyl-N,N′-di(m-tolyl)-benzidine (TPD) thicknesses. The thicknesses of TPD were varied from 5 nm to 50 nm. The current density of the device with a TPD thickness of 5 nm was 8.94 times higher than that with a thickness of 50 nm at a driving voltage of 10 V. According to the conduction–current characteristics of conductors, the current densities improved with a decreasing TPD thickness. Different from the current density–voltage characteristics, the current efficiency–current density characteristics showed an improved efficiency with a 50 nm TPD thickness. The current efficiencies of a device with a 5 nm TPD thickness at a driving voltage of 10 V was 0.148 and at a 50 nm TPD thickness 0.993 cd/A, which was 6.7 times higher than the 5 nm TPD thickness. These results indicated that hole transport in Organic Light-Emitting Diode (OLED) devices were more efficient with thin 5 nm TPD than with thick 50 nm TPD, while electron transport was more efficient with thick 50 nm TPD, which caused conflicting results in the current efficiency-current density and current density-voltage characteristics according to TPD thicknesses.
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spelling pubmed-64711922019-04-27 Effects of the Thickness of N,N′-diphenyl-N,N′-di(m-tolyl)-benzidine on the Electro-Optical Characteristics of Organic Light-Emitting Diodes Park, Sang-Geon Lee, Won Jae Song, Min Jong Shin, Johngeon Kim, Tae Wan Materials (Basel) Article We examined the electro-optical characteristics of organic light emitting diodes according to the N,N′-diphenyl-N,N′-di(m-tolyl)-benzidine (TPD) thicknesses. The thicknesses of TPD were varied from 5 nm to 50 nm. The current density of the device with a TPD thickness of 5 nm was 8.94 times higher than that with a thickness of 50 nm at a driving voltage of 10 V. According to the conduction–current characteristics of conductors, the current densities improved with a decreasing TPD thickness. Different from the current density–voltage characteristics, the current efficiency–current density characteristics showed an improved efficiency with a 50 nm TPD thickness. The current efficiencies of a device with a 5 nm TPD thickness at a driving voltage of 10 V was 0.148 and at a 50 nm TPD thickness 0.993 cd/A, which was 6.7 times higher than the 5 nm TPD thickness. These results indicated that hole transport in Organic Light-Emitting Diode (OLED) devices were more efficient with thin 5 nm TPD than with thick 50 nm TPD, while electron transport was more efficient with thick 50 nm TPD, which caused conflicting results in the current efficiency-current density and current density-voltage characteristics according to TPD thicknesses. MDPI 2019-03-22 /pmc/articles/PMC6471192/ /pubmed/30909501 http://dx.doi.org/10.3390/ma12060966 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
Park, Sang-Geon
Lee, Won Jae
Song, Min Jong
Shin, Johngeon
Kim, Tae Wan
Effects of the Thickness of N,N′-diphenyl-N,N′-di(m-tolyl)-benzidine on the Electro-Optical Characteristics of Organic Light-Emitting Diodes
title Effects of the Thickness of N,N′-diphenyl-N,N′-di(m-tolyl)-benzidine on the Electro-Optical Characteristics of Organic Light-Emitting Diodes
title_full Effects of the Thickness of N,N′-diphenyl-N,N′-di(m-tolyl)-benzidine on the Electro-Optical Characteristics of Organic Light-Emitting Diodes
title_fullStr Effects of the Thickness of N,N′-diphenyl-N,N′-di(m-tolyl)-benzidine on the Electro-Optical Characteristics of Organic Light-Emitting Diodes
title_full_unstemmed Effects of the Thickness of N,N′-diphenyl-N,N′-di(m-tolyl)-benzidine on the Electro-Optical Characteristics of Organic Light-Emitting Diodes
title_short Effects of the Thickness of N,N′-diphenyl-N,N′-di(m-tolyl)-benzidine on the Electro-Optical Characteristics of Organic Light-Emitting Diodes
title_sort effects of the thickness of n,n′-diphenyl-n,n′-di(m-tolyl)-benzidine on the electro-optical characteristics of organic light-emitting diodes
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6471192/
https://www.ncbi.nlm.nih.gov/pubmed/30909501
http://dx.doi.org/10.3390/ma12060966
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