Influence of the hole transport layer on the performance of organic light-emitting diodes

Journal Article · Fri Jan 01 04:00:00 EST 1999 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.369413· OSTI ID:300135

Giebeler, C; Antoniadis, H ^[1]; Bradley, D D ^[2]; Shirota, Y ^[3]

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1. Hewlett Packard Laboratories, 3500 Deer Creek Road, Palo Alto, California 94304 (United States)
2. Dept. of Physics, The University of Sheffield, Sheffield S3 7RH, (United Kingdom)
3. Dept. of Applied Chemistry, Faculty of Engineering, Osaka University, Yamadaoka, Suita, Osaka 565 (Japan)

We investigate the influence of the hole-transporting layer (HTL) on the performance of bilayer vapor-deposited organic light-emitting diodes. Three different HTL materials were used: m-MTDATA, triphenyl-diamine, and naphthyl-phenyl-diamine. In all cases, Alq{sub 3} was the electron-transporting layer (ETL). We measure and compare the current density-voltage (J{endash}V) and luminance{endash}voltage ({ital L}{endash}{ital V}) characteristics of these devices and we conclude that the operating voltage is controlled by the type of HTL used and the nature of the hole-injecting indium tin oxide/HTL interface. We found that the device quantum efficiency depends not only on the electron transport characteristics of the ETL but also on the energetics of the HTL/ETL interface. Analysis of the J{endash}V characteristics suggests that current flow in bilayer devices cannot be described sufficiently by a single carrier theory; both hole and electron currents should be considered. {copyright} {ital 1999 American Institute of Physics.}

• OSTI ID: 300135
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 1 Vol. 85; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CURRENT DENSITY
ELECTRIC CONDUCTIVITY
ELECTRON MOBILITY
HOLE MOBILITY
INDIUM OXIDES
INTERFACES
LIGHT EMITTING DIODES
ORGANIC COMPOUNDS
QUANTUM EFFICIENCY
TIN OXIDES