The Physics of Organic Light-Emitting Devices

1999 ◽  
Vol 558 ◽  
Author(s):  
J. Campbell Scott ◽  
George G. Malliaras ◽  
Luisa Bozano ◽  
Sue A. Carter ◽  
Sergio Ramos
Keyword(s):  
Electrical Properties ◽  
Charge Transport ◽  
Power Efficiency ◽  
Operating Voltage ◽  
Basic Principles ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Numerical Studies ◽  
Organic Light ◽  
Quantitative Understanding

ABSTRACTQualitatively, the basic principles behind the operation of OLEDs are well established. In order to optimize device parameters such as power efficiency and operating voltage, to explore the limits of performance and to understand changes in the electrical properties as diodes age, it is necessary to develop a quantitative understanding of each of the relevant processes: injection of electrons and holes at the cathode and anode, charge transport, recombination and exciton formation, and emission. In this paper, we summarize our experimental, theoretical and numerical studies to address these issues.

High Brightness White Organic Light Emitting Devices Employing Phosphorescent Iridium Complex as RGB Dopants

2007 ◽  
Vol 364-366 ◽  
pp. 1072-1076
Author(s):  
Rui Li Song ◽  
Yu Duan
Keyword(s):  
Power Efficiency ◽  
Light Emitting Diode ◽  
Iridium Complex ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light Emitting Diode ◽  
Organic Light ◽  
Color Mixing ◽  
Coordinate Changes ◽  
Cie Chromaticity

An efficient phosphorescent white organic light-emitting diode (WOLED) was realized by using a bright blue-emitting layer, iridium (III) bis [(4, 6-di-fluoropheny)-pyridinato-N, C2’] picolinate doped 4.4’-bis (9-carbazolyl)-2, 2’-dimethyl-biphenyl, together with tris (2- Phenylpyridine) iridium and bis (1-phenyl-isoquinoline) acetylacetonate iridium (III) were codoped into 4,4’-N,N’-dicarbazole-biphenyl layer to provide blue, green, and red emission for color mixing. The device emission color was controlled by varying dopant concentrations and the thickness of blue and green-red layers as well as tuning the thickness of exciton-blocking layer. The maximum luminance and power efficiency of the WOLED were 37100cd/m2 at 17 V and 7.37lm/W at 5V, respectively. The Commission Internationale de 1’Eclairage (CIE) chromaticity coordinate changes from (0.41, 0.42) to (0.37, 0.39) when the luminance rangeed from 1000cd/m2 to 30000cd/m2.

Efficiency Enhancement of Tandem Organic Light-Emitting Devices Fabricated Utilizing an Organic BEDT-TTF and HAT-CN Charge Generation Layer

2015 ◽  
Vol 15 (10) ◽  
pp. 8070-8074
Author(s):  
Dae Hun Kim ◽  
Tae Whan Kim
Keyword(s):  
Current Efficiency ◽  
Operating Voltage ◽  
Efficiency Enhancement ◽  
Charge Generation ◽  
Electrical And Optical Properties ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Highest Occupied Molecular Orbital ◽  
Organic Light Emitting Devices

The electrical and optical properties of tandem organic light-emitting devices (OLEDs) fabricated utilizing an organic bis(ethylenedithio)-tetrathiafulvalene (BEDT-TTF) and 1,4,5,8,9,11- hexaazatriphenylenehexacarbonitrile (HAT-CN) charge generation layer (CGL) were investigated to enhance their efficiency. While the operating voltage of the tandem OLEDs with a BEDT-TTF and HAT-CN CGL at 50 mA/cm2 was 11.2 V lower than that of the tandem OLEDs without a CGL, the current efficiency of the tandem OLEDs with a BEDT-TTF and a HAT-CN CGL at 50 mA/cm2 was 0.8 cd/A higher than that of the tandem OLEDs without a CGL. An increase in the current efficiency and a decrease in the operating voltage of the tandem OLEDs with a BEDT-TTF and an HAT-CN CGL were attributed to the enhancement of the electron injection due to its existence in the highest occupied molecular orbital level of the BEDT-TTF between the HAT-CN and the tris-(8- hydroxyquinoline)aluminum layer.

High-Efficient Non-Doped Type White Organic Light-Emitting Devices Using an Electron/Exciton Blocker

2005 ◽  
Vol 475-479 ◽  
pp. 1799-1804
Author(s):  
Wenfa Xie ◽  
Shi Yong Liu
Keyword(s):  
Power Efficiency ◽  
Maximum Power ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
White Region ◽  
Organic Light ◽  
High Efficient ◽  
Organic Electroluminescent ◽  
Cie Coordinates ◽  
Organic Light Emitting Devices

Non-doped type white organic electroluminescent (EL) devices have the following structure ITO/m-MTDATA (30nm) /NPB (20-dnm) /rubrene (0.1nm) /NPB (dnm) /DPVBi (20nm) /TPBi (20nm) /Alq (10nm) /LiF/Al were fabricated. The EL spectrum of the devices are dependent on the d and when d=3, the CIE coordinates of the device were well within the white region for voltage raging from 3V to 15V. This device has a luminance of 18950cd/m2 at 15V and maximum power efficiency of 5.65cd/A at 6V.

Sign in / Sign up

Export Citation Format

Share Document