Molecular design approach of increasing the triplet energy of host materials using pyrrole as a core structure

RSC Advances ◽  
2015 ◽  
Vol 5 (121) ◽  
pp. 100378-100383 ◽  
Author(s):  
Mounggon Kim ◽  
Sang Kyu Jeon ◽  
Jun Yeob Lee
Keyword(s):  
Molecular Design ◽  
Core Structure ◽  
Design Approach ◽  
Triplet Energy ◽  
Host Materials

Molecular design and synthetic approach to C2,C3,C4-modified carbazoles: high triplet energy bipolar host materials for efficient blue phosphorescent organic light emitting diodes

2019 ◽  
Vol 55 (56) ◽  
pp. 8178-8181 ◽  
Author(s):  
Rajendra Kumar Konidena ◽  
Kyung Hyung Lee ◽  
Jun Yeob Lee
Keyword(s):  
Light Emitting Diodes ◽  
Molecular Design ◽  
Organic Light Emitting Diodes ◽  
Synthetic Approach ◽  
Triplet Energy ◽  
Light Emitting ◽  
Organic Light ◽  
Host Materials ◽  
Blue Phosphorescent

Herein, we report the first examples of the design of and synthetic approach to C3/C4 and C2/C3/C4-modified carbazole based high triplet energy bipolar host materials for blue phosphorescent organic light emitting diodes.

Molecular design of triazine and carbazole based host materials for blue phosphorescent organic emitting diodes

2015 ◽  
Vol 17 (20) ◽  
pp. 13553-13558 ◽  
Author(s):  
Mounggon Kim ◽  
Sang Kyu Jeon ◽  
Seok-Ho Hwang ◽  
Jun Yeob Lee
Keyword(s):  
Molecular Design ◽  
Methyl Substituent ◽  
Triplet Energy ◽  
Host Materials ◽  
Blue Phosphorescent

The triplet energy of the host was managed by inserting a methyl substituent in the phenyl linkage between triazine and carbazole.

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.

Fluorene-Based Phosphine Oxide Host Materials for Blue Electrophosphorescence: An Effective Strategy for a High Triplet Energy Level

2011 ◽  
Vol 17 (9) ◽  
pp. 2592-2596 ◽  
Author(s):  
Donghui Yu ◽  
Yongbiao Zhao ◽  
Hui Xu ◽  
Chunmiao Han ◽  
Dongge Ma ◽  
...  
Keyword(s):  
Energy Level ◽  
Phosphine Oxide ◽  
Effective Strategy ◽  
Triplet Energy ◽  
Host Materials

Controlling the exciton lifetime of blue thermally activated delayed fluorescence emitters using a heteroatom-containing pyridoindole donor moiety

2017 ◽  
Vol 4 (4) ◽  
pp. 619-624 ◽  
Author(s):  
Gyeong Heon Kim ◽  
Raju Lampande ◽  
Joon Beom Im ◽  
Jung Min Lee ◽  
Ju Young Lee ◽  
...  
Keyword(s):  
Molecular Design ◽  
Delayed Fluorescence ◽  
Energy Splitting ◽  
Triplet Energy ◽  
High Quantum Efficiency ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Exciton Lifetime ◽  
Low Efficiency ◽  
Donor Moiety

We demonstrate a promising molecular design approach to achieve short exciton lifetime, small singlet and triplet energy splitting and high photoluminescence quantum yield in thermally activated delayed fluorescence emitters for high quantum efficiency and low efficiency roll-off characteristics in OLEDs.

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