A5056836285- Organic Light-Emitting Diodes Research
- Organic Electronics and Photovoltaics
- Conducting polymers and applications
- Thin-Film Transistor Technologies
- Quantum Dots Synthesis And Properties
- Nanomaterials and Printing Technologies
- Luminescence and Fluorescent Materials
- Molecular Junctions and Nanostructures
- Vibration Control and Rheological Fluids
- Semiconductor Lasers and Optical Devices
- Nanofabrication and Lithography Techniques
- ZnO doping and properties
- Chalcogenide Semiconductor Thin Films
- Seismic Performance and Analysis
- Perovskite Materials and Applications
- Advanced Sensor and Energy Harvesting Materials
- Dielectric materials and actuators
- Green IT and Sustainability
- Semiconductor materials and devices
- Lanthanide and Transition Metal Complexes
- Innovative Microfluidic and Catalytic Techniques Innovation
- Advancements in Battery Materials
- Advanced Materials and Mechanics
- Hydrogen Storage and Materials
- Phase-change materials and chalcogenides
Dankook University
2016-2025
Government of the Republic of Korea
2015-2019
University of Oregon
2018
Yong In University
2018
Korea Advanced Institute of Science and Technology
1998-2013
Samsung (South Korea)
2003-2013
Korea Institute of Science and Technology
2005-2008
Applied Materials (United States)
2002
University of Massachusetts Amherst
2002
Plasma Technology (United States)
1992-1995
Abstract Dual emitting cores for thermally activated delayed fluorescent (TADF) emitters were developed. Relative to the corresponding TADF emitter with a single core dual core, 3,3′,5,5′‐tetra(carbazol‐9‐yl)‐[1,1′‐biphenyl]‐2,2′,6,6′‐tetracarbonitrile, showed enhanced light absorption accompanied by high photoluminescence quantum yield. The and power efficiencies of devices cores.
Highly efficient solution‐processed blue thermally activated delayed fluorescent (TADF) devices are developed by designing soluble TADF emitters. The solubility and emission color could be managed introducing F as an electron withdrawing unit instead of CN. Two emitters synthesized show a high external quantum efficiency 20.0% with coordinate (0.16,0.26), it is the best reported in devices. device performances comparable to those vacuum‐processed
Graphene electronic circuits are prepared on paper substrates by using graphene nanoplates and applied to foldable paper-based electronics. The show a small change in conductance under various folding angles maintain an path after repetition of unfolding. Foldable applications with exhibit excellent stability.
Efficient white-light-emitting diodes (WLEDs) have been developed using a polyfluorene-type blue-emitting conjugated polymer doped with green and red phosphorescent dyes. The emission spectrum of the polymer, which has very high luminescent efficiency, shows large spectral overlap absorbance iridium complexes. Also, efficient energy transfer from to complexes is observed. Poly(N-vinyl carbazole) used improve miscibility between because their poor chemical compatibility phase separation. A...
Abstract We have investigated the possibility of fabricating quantum dot light‐emitting diodes (QLEDs) using inkjet printing technology, which is most attractive method for full‐color patterning QLED displays. By controlling (QD) ink formulation and condition, we successfully patterned pixels in 60‐in ultrahigh definition TV format, has a resolution 73 per inch. The inkjet‐printed QLEDs exhibited maximum luminance 2500 cd/m 2 . Although performance low compared with that fabricated...
White light emission was obtained from a light-emitting diode prepared polymer/quantum dot nanocomposites consisting of poly(9,-dihexylfluorene-2,7-divinylene- m-phenylenevinylene-stat-p-phenylenevinylene) (PDHFPPV) and two kinds CdSe nanoparticles with different particle size. Blue the polymer, green ?nm red CdSe, which is triggered by partial excitation energy transfer jointly contribute to white organic?inorganic hybrid device. Also, blue-emitting matrix polymer makes device preparation...
We have investigated the impact of ink formulation on properties an inkjet-printed small molecular mixed host in a phosphorescent organic light-emitting diode (PhOLED). Host solubility, film roughness, and device efficiency improved by blending tris(4-carbazoyl-9-ylphenyl)amine (TCTA) with pyrido[3′,2′:4,5]furo[2,3-b]pyridine (3CzPFP). At ratio 60:40 (TCTA/3CzPFP), brightness increased 33%, roll-off at 1000 cd/m2 dropped to well below 10%, luminance half-lifetime (LT50) 80% comparison single...
We have presented a physical concept for enhancing efficiency and lifetime of doped electrophosphorescent organic light-emitting devices. In order to provide control parameter higher device performance, stepwise doping concentration profile at the emission layer was prepared. A more than 30% improvement power obtained green with ratio layer-hole transport interface. explained carrier trapping mechanism direct recombination an exciton in iridium-based dopant system. When compared device,...
Laser‐induced thermal imaging (LITI) has been used to pattern polymeric light‐emitting devices (see Figure). Most commercial polymers (LEPs) are not suitable for LITI because of strong cohesion within the LEP layer. To reduce this and achieve excellent image quality, transfer layers based on blends LEPs inert were used. The introduction amorphous hole‐transporting materials also enhanced brightness devices.
Abstract Dual emitting cores for thermally activated delayed fluorescent (TADF) emitters were developed. Relative to the corresponding TADF emitter with a single core dual core, 3,3′,5,5′‐tetra(carbazol‐9‐yl)‐[1,1′‐biphenyl]‐2,2′,6,6′‐tetracarbonitrile, showed enhanced light absorption accompanied by high photoluminescence quantum yield. The and power efficiencies of devices cores.
Charge-carrier and exciton confinement is essential for efficiency stability enhancment of electrophosphorescent devices. Emission-layer lifetimes a 4,4′-N,N′-dicarbazole-biphenyl host doped with either red- or green- emitting dye (upper lower figures) show strong dependence near independence, respectively, on the type blocking layer used (four are shown). This explained using energy- level differences corresponding charge-trapping behavior.
Abstract Polypyrrole nanoparticles were prepared by emulsion polymerization, and the surface charge of PPy was controlled mixed surfactant system dodecylbenzene sulfonic acid isooctylphenyl ether. The shape size could be changing concentration surfactant. In addition, it confirmed that with good conductivity obtained this preparation method. Consequently, well dispersed 60–100 nm in diameter cubic whose 56.53 S/cm. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci,