Seok-Ho Hwang

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A novel tetrakis(terpyridinyl)porphyrin derivative and its Ru(II) complexes were efficiently synthesized using microwave enhanced synthesis and shown to possess photovoltaic properties. Transmission electron microscopy and selected area electron diffraction were used to investigate its nanowire self-assembly.
Mathematics and art converge in the fractal forms that also abound in nature. We used molecular self-assembly to create a synthetic, nanometer-scale, Sierpinski hexagonal gasket. This nondendritic, perfectly self-similar fractal macromolecule is composed of bis-terpyridine building blocks that are bound together by coordination to 36 Ru and 6 Fe ions to(More)
Highly efficient green thermally activated delayed fluorescent organic light-emitting diodes with an external quantum efficiency of 31.2% were investigated by using 3-(3-(carbazole-9-yl)phenyl) pyrido[3',2':4,5]furo[2,3-b]pyridine (3CzPFP) derived from carbazole and pyrido[3',2':4,5]furo[2,3-b]pyridine. The host material showed well-matched(More)
CdS nanoparticles on the surface of single-walled carbon nanotubes (SWNTs) were templated and stabilized through the initial attachment of 1 --> 3 C-branched amide-based dendrons and were both photophysically and morphologically characterized. The CdS clusters were shown to be ca. 1.4 nm in diameter as calculated from their optical absorption spectra and(More)
Carbazole- and triazine-derived thermally activated delayed fluorescent (TADF) emitters, with three donor units and an even distribution of the highest occupied molecular orbital, achieve high external quantum efficiencies of above 25% in blue and green TADF devices.
Benzofurocarbazole and benzothienocarbazole were used as electron donors of thermally activated delayed fluorescence (TADF) emitters and the performances of the TADF devices were examined. The benzofurocarbazole and benzothienocarbazole donor moieties were better than carbazole as the electron donors of the TADF emitters.
The general concepts, design criteria, and physical parameters, such as component placement and electroluminescence, that relate to the construction of OLED devices are described, followed by a discussion of the current literature detailing the use of branched and dendritic materials as the key electroluminescent elements of single- and multi-layered(More)
A ribbon-shaped chiral liquid crystalline (LC) dendrimer with photochromic azobenzene mesogens and an isosorbide chiral center (abbreviated as AZ3 DLC) was successfully synthesized and its major phase transitions were studied by using differential scanning calorimetry (DSC) and linear polarized optical microscopy (POM). Its ordered structures at different(More)
We synthesized 3-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-methylphenyl)-9-phenyl-9H-carbazole (TrzmPCz) as a new bipolar host material for blue phosphorescent organic light-emitting devices and investigated the electro-optical properties of the blue devices fabricated using the TrzmPCz host. We managed the triplet energy of the host by inserting a methyl(More)