scholarly journals White Organic Light-Emitting Diodes Using Two Phosphorescence Materials in a Starburst Hole-Transporting Layer

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Tomoya Inden ◽  
Tomoya Hishida ◽  
Masayuki Takahashi ◽  
Masato Ohsumi ◽  
Naoki Ohtani
Keyword(s):  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
The Other ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Active Layers ◽  
Organic Light ◽  
Hole Transporting ◽  
Sample Structure ◽  
Different Thickness

We fabricated two kinds of white organic light-emitting diodes (WOLEDs); one consisted of two emissive materials of red and blue, and the other of three emissive materials of red, green, and blue. The red and blue emissive materials were phosphorescent. We evaluated the thickness dependence of the CIE coordinate, the external quantum efficiency (EQE), and the luminance by changing the thicknesses of the Ir(btp)2acac and FIrpic layers. Samples consisting of three emissive materials revealed the best CIE coordinate and the best EQE in the same sample structure. On the other hand, the samples consisting of two emissive materials revealed the best CIE coordinate and the best EQE in different structures. The best CIE coordinate of (0.33, 0.36) was observed by changing the thicknesses of the stacked active layers. The best EQE was 9.73%, which was observed in the sample consisting of different thickness of stacked active layers.

White and Unsaturated Color Organic Light Emitting Diodes

1995 ◽  
Vol 413 ◽  
Author(s):  
A. Dodabalapur ◽  
M. Strukelj ◽  
R. H. Jordan ◽  
L. J. Rothberg ◽  
T. M. Miller
Keyword(s):  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Optically Active ◽  
Organic Light Emitting Diodes ◽  
Maximum Luminance ◽  
Light Emitting ◽  
Active Layers ◽  
Organic Light ◽  
Emission Color ◽  
The Individual

ABSTRACTWe describe the principles of operation and device characteristics of novel organic light emitting diodes in which the emission originates in a number of optically active layers. The effective emission color can be controlled by adjusting the thicknesses of the individual layers, and in this manner white and other unsaturated color LEDs with external quantum efficiency > 0.5% have been fabricated. The maximum luminance that has been achieved is ∼4,700 Cd/m2.

scholarly journals High efficiency blue organic light-emitting diodes with below-bandgap electroluminescence

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maria Vasilopoulou ◽  
Abd. Rashid bin Mohd Yusoff ◽  
Matyas Daboczi ◽  
Julio Conforto ◽  
Anderson Emanuel Ximim Gavim ◽  
...  
Keyword(s):  
High Efficiency ◽  
Light Emitting Diodes ◽  
High Mobility ◽  
Organic Light Emitting Diodes ◽  
Triplet Energy ◽  
Material Interface ◽  
Light Emitting ◽  
Thermally Activated ◽  
Organic Light ◽  
Hole Transporting

AbstractBlue organic light-emitting diodes require high triplet interlayer materials, which induce large energetic barriers at the interfaces resulting in high device voltages and reduced efficiencies. Here, we alleviate this issue by designing a low triplet energy hole transporting interlayer with high mobility, combined with an interface exciplex that confines excitons at the emissive layer/electron transporting material interface. As a result, blue thermally activated delay fluorescent organic light-emitting diodes with a below-bandgap turn-on voltage of 2.5 V and an external quantum efficiency (EQE) of 41.2% were successfully fabricated. These devices also showed suppressed efficiency roll-off maintaining an EQE of 34.8% at 1000 cd m−2. Our approach paves the way for further progress through exploring alternative device engineering approaches instead of only focusing on the demanding synthesis of organic compounds with complex structures.

Low driving voltage and high stability organic light-emitting diodes with rhenium oxide-doped hole transporting layer

2007 ◽  
Vol 91 (1) ◽  
pp. 011113 ◽  
Author(s):  
Dong-Seok Leem ◽  
Hyung-Dol Park ◽  
Jae-Wook Kang ◽  
Jae-Hyun Lee ◽  
Ji Whan Kim ◽  
...  
Keyword(s):  
High Stability ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Driving Voltage ◽  
Rhenium Oxide ◽  
Light Emitting ◽  
Organic Light ◽  
Hole Transporting

An oligocarbazole-encapsulated heteroleptic red iridium complex for solution-processed nondoped phosphorescent organic light-emitting diodes with over 10% external quantum efficiency

2017 ◽  
Vol 5 (23) ◽  
pp. 5749-5756 ◽  
Author(s):  
Lingcheng Chen ◽  
Shumeng Wang ◽  
Zhimin Yan ◽  
Junqiao Ding ◽  
Lixiang Wang
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Iridium Complex ◽  
Solution Processed ◽  
Light Emitting ◽  
Organic Light

By fully encapsulating the heteroleptic red Ir complex with carbazole dendrons, solution-processed nondoped electrophosphorescent devices reveal over 10% EQE.

Solution-processable highly efficient deep-red and orange organic light-emitting diodes based on multi-functional Ir(iii) complexes

2017 ◽  
Vol 5 (38) ◽  
pp. 10029-10038 ◽  
Author(s):  
Woosum Cho ◽  
Ganguri Sarada ◽  
Athithan Maheshwaran ◽  
Yeong-Soon Gal ◽  
Yeonsig Nam ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Improve Performance ◽  
Light Emitting ◽  
Highly Efficient ◽  
Organic Light ◽  
Hole Transporting ◽  
Solution Processable

Linking the hole transporting/electron transporting functional moieties to the Ir(iii) complex is a key strategy to improve performance of PhOLEDs.

scholarly journals An external quantum efficiency of >20% from solution-processed poly(dendrimer) organic light-emitting diodes

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Fatemeh Maasoumi ◽  
Ross D. Jansen-van Vuuren ◽  
Paul E. Shaw ◽  
Emma V. Puttock ◽  
Ravi Chandra Raju Nagiri ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Organic Light Emitting Diodes ◽  
Solution Processed ◽  
Light Emitting ◽  
Organic Light
Sign in / Sign up

Export Citation Format

Share Document