Using reach-through techniques to improve the external power efficiency of silicon CMOS light emitting devices

2010 ◽  
Author(s):  
Monuko du Plessis ◽  
Petrus J. Venter ◽  
Alfons W. Bogalecki
Keyword(s):  
Power Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
External Power ◽  
Silicon Cmos

scholarly journals Pyridinyl-Carbazole Fragments Containing Host Materials for Efficient Green and Blue Phosphorescent OLEDs

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4615
Author(s):  
Dovydas Blazevicius ◽  
Daiva Tavgeniene ◽  
Simona Sutkuviene ◽  
Ernestas Zaleckas ◽  
Ming-Ruei Jiang ◽  
...  
Keyword(s):  
Current Efficiency ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Power Efficiency ◽  
Triplet Energy ◽  
New Host ◽  
High Brightness ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Host Materials

Pyridinyl-carbazole fragments containing low molar mass compounds as host derivatives H1 and H2 were synthesized, investigated, and used for the preparation of electro-phosphorescent organic light-emitting devices (PhOLEDs). The materials demonstrated high stability against thermal decomposition with the decomposition temperatures of 361–386 °C and were suitable for the preparation of thin amorphous and homogeneous layers with very high values of glass transition temperatures of 127–139 °C. It was determined that triplet energy values of the derivatives are, correspondingly, 2.82 eV for the derivative H1 and 2.81 eV for the host H2. The new derivatives were tested as hosts of emitting layers in blue, as well as in green phosphorescent OLEDs. The blue device with 15 wt.% of the iridium(III)[bis(4,6-difluorophenyl)-pyridinato-N,C2′]picolinate (FIrpic) emitter doping ratio in host material H2 exhibited the best overall characteristics with a power efficiency of 24.9 lm/W, a current efficiency of 23.9 cd/A, and high value of 10.3% of external quantum efficiency at 100 cd/m2. The most efficient green PhOLED with 10 wt% of Ir(ppy)3 {tris(2-phenylpyridine)iridium(III)} in the H2 host showed a power efficiency of 34.1 lm/W, current efficiency of 33.9 cd/A, and a high value of 9.4% for external quantum efficiency at a high brightness of 1000 cd/m2, which is required for lighting applications. These characteristics were obtained in non-optimized PhOLEDs under an ordinary laboratory atmosphere and could be improved in the optimization process. The results demonstrate that some of the new host materials are very promising components for the development of efficient phosphorescent devices.

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.

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-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.

High power efficiency in Si-nc/SiO2 multilayer light emitting devices by bipolar direct tunneling

2009 ◽  
Vol 94 (22) ◽  
pp. 221110 ◽  
Author(s):  
A. Marconi ◽  
A. Anopchenko ◽  
M. Wang ◽  
G. Pucker ◽  
P. Bellutti ◽  
...  
Keyword(s):  
High Power ◽  
Power Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Direct Tunneling ◽  
High Power Efficiency

An ambipolar phosphine oxide-based host for high power efficiency blue phosphorescent organic light emitting devices

2009 ◽  
Vol 94 (22) ◽  
pp. 223304 ◽  
Author(s):  
Evgueni Polikarpov ◽  
James S. Swensen ◽  
Neetu Chopra ◽  
Franky So ◽  
Asanga B. Padmaperuma
Keyword(s):  
Phosphine Oxide ◽  
High Power ◽  
Power Efficiency ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices ◽  
Blue Phosphorescent ◽  
High Power Efficiency

Enhancement of hole-injection and power efficiency of organic light emitting devices using an ultra-thin ZnO buffer layer

2009 ◽  
Vol 479 (1-2) ◽  
pp. 520-524 ◽  
Author(s):  
Hsin-Hsuan Huang ◽  
Sheng-Yuan Chu ◽  
Po-Ching Kao ◽  
Yung-Chen Chen ◽  
Ming-Ru Yang ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Power Efficiency ◽  
Hole Injection ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Organic Light ◽  
Organic Light Emitting Devices ◽  
Zno Buffer Layer
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