A new electron transporting material for effective hole-blocking and improved charge balance in highly efficient phosphorescent organic light emitting diodes
A highly efficient new benzoimidazole phosphine oxide based electron transporting material, bis(1-phenyl-1H-benzo[d]imidazole )phenylphosphine oxide (BIPO), was designed, synthesized by condensation, nucleophilic substitution and oxidation reactions, and confirmed using various spectroscopic studies...
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Published in | Journal of materials chemistry. C, Materials for optical and electronic devices Vol. 1; no. 11; pp. 2217 - 2223 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
01.01.2013
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Subjects | |
Online Access | Get full text |
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Summary: | A highly efficient new benzoimidazole phosphine oxide based electron transporting material, bis(1-phenyl-1H-benzo[d]imidazole )phenylphosphine oxide (BIPO), was designed, synthesized by condensation, nucleophilic substitution and oxidation reactions, and confirmed using various spectroscopic studies. It shows a thermal stability ( Delta T sub(5%)) of 451 degree C with a glass transition temperature of 129 degree C from the thermogravimetric analysis and differential scanning calorimetry studies. BIPO used as an efficient electron transport layer (ETL) in a green emitting phosphorescent organic light emitting diode, ITO/4,4'-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl (30 nm)/4,4',4''-tris(carbazole-9-yl)triphenylamin e 10 nm)/(4,4'-N,N'-dica rbazole)biphenyl (CBP) host doped with Ir(ppy) sub(3) dopant (5%) (30 nm)/ETL (40 nm)/LiF (1 nm)/Al (100 nm), serves as an effective hole-blocking material and improves the charge balance in the device, resulting in higher device efficiencies of 22.19%, 68.3 cd A super(-1) and 24.4 lm W super(-1) with a maximum luminance of 72 080 cd m super(-2) compared to those (17.03%, 52.0 cd A super(-1) and 20.9 lm W super(-1) with a maximum luminance of 33 490 cd m super(-2)) of a device using a widely used ETL, 1,3,5-tris(m-pyrid-3-yl-phenyl)benzene. These results show that the new BIPO ETL could be very useful in efficient organic light emitting diodes. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 2050-7526 2050-7534 |
DOI: | 10.1039/c3tc00801k |