scholarly journals Molecular Design Approach Managing Molecular Orbital Superposition for High Efficiency without Color Shift in Thermally Activated Delayed Fluorescent Organic Light-Emitting Diodes

2019 ◽  
Vol 25 (7) ◽  
pp. 1829-1834 ◽  
Author(s):  
Mounggon Kim ◽  
Seong-Jun Yoon ◽  
Si Hyun Han ◽  
Ramin Ansari ◽  
John Kieffer ◽  
...  
Keyword(s):  
Molecular Orbital ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Molecular Design ◽  
Organic Light Emitting Diodes ◽  
Design Approach ◽  
Light Emitting ◽  
Thermally Activated ◽  
Organic Light ◽  
Color Shift

scholarly journals Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)

2018 ◽  
Vol 14 ◽  
pp. 282-308 ◽  
Author(s):  
Thanh-Tuân Bui ◽  
Fabrice Goubard ◽  
Malika Ibrahim-Ouali ◽  
Didier Gigmes ◽  
Frédéric Dumur
Keyword(s):  
Molecular Orbital ◽  
Light Emitting Diodes ◽  
Molecular Design ◽  
Delayed Fluorescence ◽  
Organic Light Emitting Diodes ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
Organic Light ◽  
Recent Advances

The design of highly emissive and stable blue emitters for organic light emitting diodes (OLEDs) is still a challenge, justifying the intense research activity of the scientific community in this field. Recently, a great deal of interest has been devoted to the elaboration of emitters exhibiting a thermally activated delayed fluorescence (TADF). By a specific molecular design consisting into a minimal overlap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) due to a spatial separation of the electron-donating and the electron-releasing parts, luminescent materials exhibiting small S1–T1 energy splitting could be obtained, enabling to thermally upconvert the electrons from the triplet to the singlet excited states by reverse intersystem crossing (RISC). By harvesting both singlet and triplet excitons for light emission, OLEDs competing and sometimes overcoming the performance of phosphorescence-based OLEDs could be fabricated, justifying the interest for this new family of materials massively popularized by Chihaya Adachi since 2012. In this review, we proposed to focus on the recent advances in the molecular design of blue TADF emitters for OLEDs during the last few years.

Molecular Design Opening Two Emission Pathways for High Efficiency and Long Lifetime in Thermally Activated Delayed Fluorescent Organic Light-Emitting Diodes

2021 ◽  
Author(s):  
Ha Lim Lee ◽  
Kyung Hyung Lee ◽  
Jun Yeob Lee ◽  
Ho Jung Lee
Keyword(s):  
Quantum Yield ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Molecular Design ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Thermally Activated ◽  
Photoluminescence Quantum Yield ◽  
Organic Light ◽  
Long Lifetime

High efficiency and long lifetime thermally activated delayed fluorescent (TADF) organic light-emitting diodes (OLEDs) were developed using a novel molecular design with two emission pathways for high photoluminescence quantum yield...

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.

Lowest unoccupied molecular orbital managing function of CN-substituted dibenzofuran in high triplet energy hosts for blue thermally-activated delayed fluorescent organic light-emitting diodes

2021 ◽  
Author(s):  
Sung Yong Byun ◽  
Kyung Hyung Lee ◽  
Jun Yeob Lee
Keyword(s):  
Molecular Orbital ◽  
Light Emitting Diodes ◽  
Delayed Fluorescence ◽  
Organic Light Emitting Diodes ◽  
Triplet Energy ◽  
Thermally Activated Delayed Fluorescence ◽  
Light Emitting ◽  
Thermally Activated ◽  
Organic Light ◽  
Lowest Unoccupied Molecular Orbital

The effect of lowest unoccupied molecular orbital (LUMO) management of high triplet energy electron transport type hosts on the device performance of blue thermally-activated delayed fluorescence (TADF) organic light-emitting diodes...

P-170: Molecular Design of Sensitizer for High Efficiency in Hyper-fluorescent Organic Light-Emitting Diodes

2018 ◽  
Vol 49 (1) ◽  
pp. 1800-1803
Author(s):  
Ji Seon Jang ◽  
Si Hyun Han ◽  
Hye Won Choi ◽  
Kyoung Soo Yook ◽  
Jun Yeob Lee
Keyword(s):  
High Efficiency ◽  
Light Emitting Diodes ◽  
Molecular Design ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light

Spatially optimized quaternary phosphine oxide host materials for high-efficiency blue phosphorescence and thermally activated delayed fluorescence organic light-emitting diodes

2015 ◽  
Vol 3 (43) ◽  
pp. 11385-11396 ◽  
Author(s):  
Dongxue Ding ◽  
Zhen Zhang ◽  
Ying Wei ◽  
Pengfei Yan ◽  
Hui Xu
Keyword(s):  
Phosphine Oxide ◽  
High Efficiency ◽  
Light Emitting Diodes ◽  
Spatial Optimization ◽  
Delayed Fluorescence ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Thermally Activated ◽  
Organic Light ◽  
Host Materials

Spatial optimization of host materials for highly efficient blue organic light-emitting diodes was rationally performed on the basis of a series of ternary and quaternary phosphine oxide materials.

High efficiency above 20% in polymeric thermally activated delayed fluorescent organic light-emitting diodes by a host embedded backbone structure

2019 ◽  
Vol 10 (35) ◽  
pp. 4872-4878 ◽  
Author(s):  
Yun Hwan Park ◽  
Ho Jin Jang ◽  
Jun Yeob Lee
Keyword(s):  
High Efficiency ◽  
Light Emitting Diodes ◽  
Light Emitting Diode ◽  
Organic Light Emitting Diodes ◽  
Light Emitting ◽  
Organic Light Emitting Diode ◽  
Thermally Activated ◽  
Highly Efficient ◽  
Organic Light ◽  
Backbone Structure

A highly efficient polymeric thermally activated delayed fluorescent (TADF) organic light-emitting diode was developed by synthesizing a copolymer with 9-vinylcarbazole (VCz) and TADF repeating units.

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