Current-Voltage Characteristics of Single Layer Polymer Light Emitting Diodes Under High Intensity Electrical Excitation

1999 ◽  
Vol 561 ◽  
Author(s):  
B. Ruhstaller ◽  
J.C. Scott ◽  
P.J. Brock ◽  
S.A. Carter
Keyword(s):  
Electric Fields ◽  
High Intensity ◽  
Single Layer ◽  
Electrical Excitation ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Single Carrier ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Polymer Light Emitting Devices

ABSTRACTWe study the current-voltage characteristics of both double and single carrier polymer light emitting devices in the high intensity electrical excitation regime. Single layer devices are investigated with the orange-emitting MEH-PPV as the active polymer. Performing very low duty (≈0.001 %) pulsed electroluminescence measurements with electric fields up to 1*109 V/m, we observe for the hole-dominated devices a space charge limited current with a saturating mobility and a saturating external quantum efficiency of 1%. For double carrier devices, the current starts to saturate in the high-field regime, appoaching Ohmic-like behavior. We report current densities of 100 A/cm2and brightnesses of 7*105 cd/m2. The spectral features are monitored below the onset of degradation.

Enhanced carrier balance by organic salt doping in single-layer polymer light-emitting devices

2009 ◽  
Vol 10 (7) ◽  
pp. 1345-1351 ◽  
Author(s):  
Dong-Hyun Lee ◽  
Jong Hyeok Park ◽  
Heeyeop Chae ◽  
Sung M. Cho
Keyword(s):  
Single Layer ◽  
Organic Salt ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Polymer Light Emitting Devices

Tetraphenylmethane-Based 1,3,4-Oxadiazole as Electron Transporting Materials in Organic Light-Emitting Devices

1999 ◽  
Vol 598 ◽  
Author(s):  
Chin-Ti Chen ◽  
Tzu-Yao J. Lin ◽  
Hsiu-Chih Yeh ◽  
Li-Hsin Jan ◽  
Easwaramoorthy Balasubramaniam ◽  
...  
Keyword(s):  
Glass Phase ◽  
Molecular Design ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Current Voltage ◽  
Electron Transporting Layer ◽  
Current Voltage Characteristics

ABSTRACTA series of tetrahedral tetramers of 2,5-diphenyl substituted 1,3,4-oxadiazole compounds were synthesized and characterized for electron-transporting layer (ETL) in organic light-emitting diode (OLED). The multiple-branch design of the oxadiazole tetramers intends to increase the melting temperature and to generate glass phase of the low molar mass derivative such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD). We observed temperatures of the glass phase transition for the oxadiazole tetramer with appropriate peripheral substituents, indicative of amorphous characteristics of the molecule in spite of highly symmetrical molecular framework. The luminescence-current-voltage characteristics of multilayer OLED devices containing the oxadiazole tetramer or PBD as ETL were examined to evaluate the efficiency of our multiple-branch molecular design.

GaSb-based Nanocomposites as IR-Emitters

2002 ◽  
Vol 737 ◽  
Author(s):  
Ludmila Bakueva ◽  
Sergei Musikhin ◽  
Edward H. Sargent ◽  
Stephan Schulz
Keyword(s):  
Communication Systems ◽  
Infrared Light ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Strongly Nonlinear ◽  
Current Voltage ◽  
Optical Communication Systems ◽  
Capacitance Voltage ◽  
Nonlinear Character ◽  
Current Voltage Characteristics

ABSTRACTNanocomposites consisting of GaSb nanocrystals in a conducting polymer matrix were fabricated and investigated. The current-voltage characteristics of the nanocomposite-based diode structures have a symmetric but strongly nonlinear character. Capacitance-voltage characteristics of the structures were investigated both in the dark and under illumination and compared with those of a pure polymer. At applied voltages exceeding 7–10 V (for different samples) electroluminescence begins and steeply increases. The position of the maximum of the measured electroluminescence spectra can be made to vary in the 1.3 – 1.6 μm wavelengths region by changing nanocrystal size. Photoluminescence spectra have a maximum nearly coinciding with that of electroluminescence but of considerably larger width. The results demonstrate the promise of GaSb-based nanocomposites for infrared light-emitting devices operating in the 1.3–1.6 μm spectral region used in optical communication systems.

Novel iridium complexes as yellow phosphorescent emitters for single-layer yellow and white polymer light-emitting diodes

2016 ◽  
Vol 4 (27) ◽  
pp. 6626-6633 ◽  
Author(s):  
Aihui Liang ◽  
Gui Huang ◽  
Sheng Dong ◽  
Xiaoyan Zheng ◽  
Jia Zhu ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Single Layer ◽  
Iridium Complexes ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Polymer Light Emitting Diodes ◽  
Polymer Light Emitting Devices

Both yellow and white polymer light-emitting devices are achieved using novel yellow phosphorescent iridium complexes with triphenylamine- and fluorene-functionalized cyclometalating ligands as dopants.

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