Acceptor–Donor–Acceptor‐Type Orange–Red Thermally Activated Delayed Fluorescence Materials Realizing External Quantum Efficiency Over 30% with Low Efficiency Roll‐Off

2021 ◽  
pp. 2007724
Author(s):  
Durai Karthik ◽  
Young Hun Jung ◽  
Hyuna Lee ◽  
Soonjae Hwang ◽  
Bo‐Min Seo ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Donor Acceptor ◽  
Low Efficiency

Rational design of efficient orange-red to red thermally activated delayed fluorescence emitters for OLEDs with external quantum efficiency of up to 26.0% and reduced efficiency roll-off

2020 ◽  
Vol 8 (5) ◽  
pp. 1614-1622 ◽  
Author(s):  
Jixiong Liang ◽  
Chenglong Li ◽  
Yuanyuan Cui ◽  
Zhiqiang Li ◽  
Jiaxuan Wang ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Rational Design ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Donor Acceptor ◽  
Low Efficiency

A class of novel donor–acceptor orange-red to red thermally activated delayed fluorescence (TADF) emitters with a maximum external quantum efficiency (EQE) of up to 26.0% and extremely low efficiency roll-off have been designed and synthesized.

An Unsymmetrical Thermally Activated Delayed Fluorescence Emitter Enables Orange-Red Electroluminescence with 31.7% External Quantum Efficiency

2021 ◽  
Author(s):  
Xuan Zeng ◽  
Yu-Hsin Huang ◽  
Shaolong Gong ◽  
Pan Li ◽  
Wei-Kai Lee ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
The Past ◽  
Donor Acceptor

The thermally activated delayed fluorescence (TADF) emitters based on donor-acceptor (D-A) configuration were continuously developed in the past few years, whereas the unsymmetrical TADF emitter with A-D-A' configuration has never...

scholarly journals Utilizing Electroplex Emission to Achieve External Quantum Efficiency up to 18.1% in Nondoped Blue OLED

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Xuejun Zhan ◽  
Zhongbin Wu ◽  
Yanbin Gong ◽  
Jin Tu ◽  
Yujun Xie ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Delayed Fluorescence ◽  
Organic Light Emitting Diodes ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
Electron Transporting Layer ◽  
Donor Acceptor ◽  
First Time

For the first time, electroplex emission is utilized to enhance the performance of nondoped blue organic light-emitting diodes (OLEDs). By decorating the twisted blue-emitting platform and adjusting the electronic structure, three molecules of 3Cz-Ph-CN, 3Cz-mPh-CN, and 3Ph-Cz-CN with a donor-acceptor structure are synthesized and investigated. When external voltage is applied, electroplex emission, which contributes to the emission performance of OLED, can be realized at the interface between the emitting layer and the electron-transporting layer. Accordingly, high external quantum efficiency of 18.1% can be achieved, while the emission wavelength of the device can be controlled in the blue region. Our results provide the possibility to enhance the performance of OLED through electroplex emission, in addition to the generally investigated thermally activated delayed fluorescence (TADF). Excitedly, when 3Ph-Cz-CN is used as host material in orange-emitting phosphorous OLEDs (PO-01 as the dopant), unprecedented high external quantum efficiency of 27.4% can also be achieved.

Over 20% external quantum efficiency in red thermally activated delayed fluorescence organic light-emitting diodes using a reverse intersystem crossing activating host

2018 ◽  
Vol 6 (20) ◽  
pp. 5363-5368 ◽  
Author(s):  
Ji Han Kim ◽  
Dong Ryun Lee ◽  
Si Hyun Han ◽  
Jun Yeob Lee
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Delayed Fluorescence ◽  
Organic Light Emitting Diodes ◽  
Intersystem Crossing ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
Organic Light

Highly efficient red thermally activated delayed fluorescence organic light-emitting diodes were developed using a reverse intersystem crossing activating host derived from phenylcarbazole and pyridofuropyridine.

High efficiency pure blue thermally activated delayed fluorescence molecules having 10H-phenoxaborin and acridan units

2015 ◽  
Vol 51 (46) ◽  
pp. 9443-9446 ◽  
Author(s):  
Masaki Numata ◽  
Takuma Yasuda ◽  
Chihaya Adachi
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Delayed Fluorescence ◽  
New Materials ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated

New materials emitting pure blue thermally activated delayed fluorescence achieve 20% external quantum efficiency and exhibit nearly concentration-independent photoluminescence.

Benzothienopyrimidine as a co-planar type rigid acceptor for high external quantum efficiency in thermally activated delayed fluorescence emitters

2019 ◽  
Vol 7 (25) ◽  
pp. 7643-7653 ◽  
Author(s):  
Chan Seok Oh ◽  
Ha Lim Lee ◽  
Wan Pyo Hong ◽  
Jun Yeob Lee
Keyword(s):  
Hydrogen Bonding ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Efficiency ◽  
Delayed Fluorescence ◽  
Planar Structure ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated

Thermally activated delayed fluorescence (TADF) emitters based on a new benzothienopyrimidine acceptor, which is rigid and can form a co-planar structure via hydrogen bonding, were developed as high-efficiency TADF emitters.

scholarly journals Thermally activated delayed fluorescence with 7% external quantum efficiency from a light-emitting electrochemical cell

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Petter Lundberg ◽  
Youichi Tsuchiya ◽  
E. Mattias Lindh ◽  
Shi Tang ◽  
Chihaya Adachi ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Active Material ◽  
Fluorescence Emission ◽  
Single Layer ◽  
Delayed Fluorescence ◽  
Electrochemical Cells ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated

AbstractWe report on light-emitting electrochemical cells, comprising a solution-processed single-layer active material and air-stabile electrodes, that exhibit efficient and bright thermally activated delayed fluorescence. Our optimized devices delivers a luminance of 120 cd m−2 at an external quantum efficiency of 7.0%. As such, it outperforms the combined luminance/efficiency state-of-the art for thermally activated delayed fluorescence light-emitting electrochemical cells by one order of magnitude. For this end, we employed a polymeric blend host for balanced electrochemical doping and electronic transport as well as uniform film formation, an optimized concentration (<1 mass%) of guest for complete host-to-guest energy transfer at minimized aggregation and efficient emission, and an appropriate concentration of an electrochemically stabile electrolyte for desired doping effects. The generic nature of our approach is manifested in the attainment of bright and efficient thermally activated delayed fluorescence emission from three different light-emitting electrochemical cells with invariant host:guest:electrolyte number ratio.

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