High‐Power‐Efficiency White Thermally Activated Delayed Fluorescence Diodes Based on Selectively Optimized Intermolecular Interactions

2020 ◽  
Vol 30 (45) ◽  
pp. 2005165
Author(s):  
Jing Zhang ◽  
Chunmiao Han ◽  
Fengsheng Du ◽  
Chunbo Duan ◽  
Ying Wei ◽  
...  
Keyword(s):  
Intermolecular Interactions ◽  
High Power ◽  
Power Efficiency ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
High Power Efficiency

scholarly journals Intermolecular interactions in molecular crystals and their effect on thermally activated delayed fluorescence of helicene-based emitters

2018 ◽  
Vol 6 (39) ◽  
pp. 10557-10568 ◽  
Author(s):  
Anastasia Klimash ◽  
Piotr Pander ◽  
Wim T. Klooster ◽  
Simon J. Coles ◽  
Przemyslaw Data ◽  
...  
Keyword(s):  
Intermolecular Interactions ◽  
Molecular Crystals ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Donor Acceptor

In crystals of donor–acceptor helicene molecules, thermally activated delayed fluorescence (TADF) is strongly enhanced by the presence of occluded hexane molecules.

scholarly journals Acceptor plane expansion enhances horizontal orientation of thermally activated delayed fluorescence emitters

2020 ◽  
Vol 6 (41) ◽  
pp. eaba7855
Author(s):  
Yepeng Xiang ◽  
Pan Li ◽  
Shaolong Gong ◽  
Yu-Hsin Huang ◽  
Chun-Yu Wang ◽  
...  
Keyword(s):  
Power Efficiency ◽  
Delayed Fluorescence ◽  
Organic Light Emitting Diodes ◽  
Dipole Orientation ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
Horizontal Orientation ◽  
Formidable Challenge ◽  
Influence Of Substituents

Manipulating orientation of organic emitters remains a formidable challenge in organic light-emitting diodes (OLEDs). Here, expansion of the acceptor plane of thermally activated delayed fluorescence (TADF) emitters was demonstrated to selectively modulate emitting dipole orientation. Two proof-of-the-concept molecules, PXZPyPM and PXZTAZPM, were prepared by introducing a planar 2-phenylpyridine or 2,4,6-triphenyl-1,3,5-triazine substituent into a prototypical molecule (PXZPM) bearing a pyrimidine core and two phenoxazine donors. This design approach suppressed the influence of substituents on electronic structures and associated optoelectronic properties. Accordingly, PXZPyPM and PXZTAZPM preserved almost the same excited states and similar emission characteristics as PXZPM. The expanded acceptor plane of PXZPyPM and PXZTAZPM resulted in a 15 to 18% increase in horizontal ratios of emitting dipole orientation. PXZPyPM supported its green device exhibiting an external quantum efficiency of 33.9% and a power efficiency of 118.9 lumen per watt, competitive with the most efficient green TADF OLEDs reported so far.

scholarly journals High efficiency and low roll-off green OLEDs with simple structure by utilizing thermally activated delayed fluorescence material as the universal host

Nanophotonics ◽  
2016 ◽  
Vol 6 (5) ◽  
pp. 1133-1140 ◽  
Author(s):  
Bo Zhao ◽  
Yanqin Miao ◽  
Zhongqiang Wang ◽  
Kexiang Wang ◽  
Hua Wang ◽  
...  
Keyword(s):  
Current Efficiency ◽  
Power Efficiency ◽  
High Efficiency ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Phenyl Sulfone ◽  
Decay Measurement ◽  
Green Fluorescent ◽  
Fluorescence Material

AbstractWe achieved high-efficiency and low-roll-off green fluorescent and phosphorescent organic light-emitting diodes (OLEDs) simultaneously by adopting the thermally activated delayed fluorescence material of bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone as the universal host. At a luminance of 1000 cd/m2, fluorescent OLEDs based on C545T get a current efficiency, power efficiency, and external quantum efficiency (EQE) of 31.8 cd/A, 25.0 lm/W, and 9.26%, respectively. This is almost the highest efficiency based on C545T at the luminance of 1000 cd/m2 to date. On the other hand, phosphorescent OLEDs with Ir(ppy)3 as the emitter realize a maximum current efficiency, power efficiency, and EQE of 64.3 cd/A, 62.4 lm/W, and 18.5%, respectively. More important, the EQE remains 17.8% at the representative luminance of 1000 cd/m2 and the roll-off ratio is just 3.78%. The transient photoluminescence decay measurement demonstrates that the up-conversion of host triplet excitons plays a key role in the high efficiency and low roll-off. More detailed discussions are also given.

Achieving high power efficiency and low roll-off OLEDs based on energy transfer from thermally activated delayed excitons to fluorescent dopants

2015 ◽  
Vol 51 (60) ◽  
pp. 11972-11975 ◽  
Author(s):  
Shipan Wang ◽  
Yuewei Zhang ◽  
Weiping Chen ◽  
Jinbei Wei ◽  
Yu Liu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Power Efficiency ◽  
High Efficiency ◽  
Delayed Fluorescence ◽  
Triplet Energy ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
External Power ◽  
Triplet Energy Transfer

A high-efficiency fluorescent organic light-emitting device with a maximum external power efficiency (PE) of 53.4 lm W−1 was fabricated through efficient triplet energy transfer from a thermally activated delayed fluorescence (TADF) host to conventional fluorescent dopants.

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