Cohosts with efficient host-to-emitter energy transfer for stable blue phosphorescent organic light-emitting diodes

Author(s):  
Soo-Ghang Ihn ◽  
Eun Suk Kwon ◽  
Yongsik Jung ◽  
Jong Soo Kim ◽  
Sungho Nam ◽  
...  

We present a high-performance blue phosphorescent organic light-emitting diode exhibiting a low operating voltage (4.1 V), high external quantum efficiency (23.4%, at 500 cd m-2) with a low efficiency roll-off...

Author(s):  
Pan Li ◽  
Yepeng Xiang ◽  
Shaolong Gong ◽  
Wei-Kai Lee ◽  
Yu-Hsin Huang ◽  
...  

Incorporating both preferential orientation of organic emitters in the emitting layer and high photoluminescence quantum yield (PLQY) is a challenging issue in the organic light-emitting diode (OLED) field. In this...


2011 ◽  
Vol 21 (4) ◽  
pp. 373
Author(s):  
Nguyen Nang Dinh ◽  
Nguyen Phuong Hoai Nam ◽  
Do Ngoc Chung

With the aim of improving the photonic efficiency of an organic light emitting diode a blend of electroluminescent polymers, poly[9-vinylcarbarzole] (PVK) and poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) was prepared. The energy transfer in the blend was investigated through the comparison of absorption, photoluminescence (PL) and current-voltage (I-V) characteristics of the blend and standard polymers. The obtained results showed that energy transfer from PVK to MEH-PPV enable to form localized excited-state complexes (e.g. exciplexes) in MEH-PPV. The PL intensity of the blended polymers was enhanced as the relative content of MEH-PPV was increased, and particularly, the highest improved PL was observed for an weight fraction of 15 wt{\%} of MEH-PPV in PVK. Organic light emitting diodes made from these blends would exhibit a large photonic efficiency.


Author(s):  
Bahadur Sk ◽  
Vasudevan Thangaraji ◽  
Nisha Yadav ◽  
Gyana Prakash Nanda ◽  
SANNIBHA DAS ◽  
...  

Non-doped, delayed fluorescence organic light-emitting diodes (OLEDs) provide a route to high performance devices and simplified device fabrication. Here, two ambipolar anthracene derivatives containing a hole-transporting di-ptolylamine or a carbazole...


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tsubasa Sasaki ◽  
Munehiro Hasegawa ◽  
Kaito Inagaki ◽  
Hirokazu Ito ◽  
Kazuma Suzuki ◽  
...  

AbstractAlthough significant progress has been made in the development of light-emitting materials for organic light-emitting diodes along with the elucidation of emission mechanisms, the electron injection/transport mechanism remains unclear, and the materials used for electron injection/transport have been basically unchanged for more than 20 years. Here, we unravelled the electron injection/transport mechanism by tuning the work function near the cathode to about 2.0 eV using a superbase. This extremely low-work function cathode allows direct electron injection into various materials, and it was found that organic materials can transport electrons independently of their molecular structure. On the basis of these findings, we have realised a simply structured blue organic light-emitting diode with an operational lifetime of more than 1,000,000 hours. Unravelling the electron injection/transport mechanism, as reported in this paper, not only greatly increases the choice of materials to be used for devices, but also allows simple device structures.


2013 ◽  
Vol 311 ◽  
pp. 424-429
Author(s):  
Kan Lin Chen ◽  
Chien Jung Huang ◽  
Zong Jin Wu ◽  
Chih Chieh Kang ◽  
Wen Ray Chen ◽  
...  

A blue organic light-emitting diode (OLED) with a double hole-transporting (DHT) structure has been developed. The blue color purity was improved by modulation the thickness of CBP layer. When the thicknesses of left CBP and right CBP are respectively 8 nm and 2 nm, the more pure blue coordinates are (0.155, 0.079), which are very close to the blue coordinates of the national television system committee (NTSC) standard (0.14, 0.08). Furthermore the current density, brightness and the luminous efficiency of device with the left CBP of 8 nm and the right CBP of 2 nm are respectively 144.7 mA/cm2, 1065 cd/m2 and 0.93 cd/A.


2004 ◽  
Vol 85 (23) ◽  
pp. 5769-5771 ◽  
Author(s):  
Masayuki Fujita ◽  
Tetsuya Ueno ◽  
Kuniaki Ishihara ◽  
Takashi Asano ◽  
Susumu Noda ◽  
...  

2018 ◽  
Vol 6 (40) ◽  
pp. 10793-10803 ◽  
Author(s):  
Shian Ying ◽  
Dezhi Yang ◽  
Xianfeng Qiao ◽  
Yanfeng Dai ◽  
Qian Sun ◽  
...  

High-performance WOLEDs realizing high efficiency and low efficiency roll-off simultaneously were achieved by strategically managing triplet excitons in the emission layer.


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