Hyo Joong Lee

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Metal sulfide (PbS and CdS) quantum dots (QDs) were prepared over mesoporous TiO2 films by improved successive ionic layer adsorption and reaction (SILAR) processes. The as-prepared QD-sensitized electrodes were combined with a cobalt complex redox couple [Co(o-phen)3]2+/3+ to make a regenerative liquid-type photovoltaic cell. The optimized PbS(More)
Redox couples based on cobalt complexes were found to be effective in regenerating both inorganic CdSe quantum dot- and organic dye-sensitizers. The hybrid sensitizer composed of CdSe QD and ruthenium sensitizer (Z907Na) dye showed a maximum power conversion efficiency of 4.76% on using cobalt(o-phen)(3)(2+/3+) as a common redox mediator.
The assembly of reduced graphene oxide (rGO) and fullerene (C(60)) into hybrid (rGO/C(60)) wires was successfully performed by employing the liquid-liquid interfacial precipitation method. The rGO sheets spontaneously wrapped C(60) wires through the π-π interaction between rGO and C(60). Structural characterization of the rGO/C(60) wires was carried out by(More)
Novel quinoxaline-based organic sensitizers using vertical (RC-21) and horizontal (RC-22) conjugation between an electron-donating triphenylamine unit and electron-accepting quinoxaline unit have been synthesized and used for dye-sensitized solar cells (DSSCs), leading to the relatively high power conversion efficiencies of 3.30 and 5.56% for RC-21 and(More)
A multilayer of CdSe quantum dots (QDs) was prepared on the mesoporous surface of a nanoparticulate TiO(2) film by a layer-by-layer (LBL) assembly using the electrostatic interaction of the oppositely charged QD surface for application as a sensitizer in QD-sensitized TiO(2) solar cells. To maximize the absorption of incident light and the generation of(More)
Layer cake: Multilayered CdSe quantum dot (QD) sensitizers are layer-by-layer assembled onto ZnO nanowires by making use of electrostatic interactions to study the effect of the layer number on the photovoltaic properties. The photovoltaic performance of QD-sensitized solar cells critically depends on this number as a result of the balance between(More)
A novel multifunctional conjugated polymer (RCP-1) composed of an electron-donating backbone (carbazole) and an electron-accepting side chain (cyanoacetic acid) connected through conjugated vinylene and terthiophene has been synthesized and tested as a photosensitizer in two major molecule-based solar cells, namely dye sensitized solar cells (DSSCs) and(More)
[Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)] (PEDOT:PSS, Baytron P) composite films were prepared under various conditions and their conductivities were studied by the current-sensing atomic force microscopy (CS-AFM) technique. Topographic and current images of pristine and additive-treated PEDOT:PSS as well as electrochemically synthesized(More)
Heparin was modified with adipic dihydrazide and covalently linked to surface-activated silica wafers. X-ray photoelectron spectroscopy was used at each stage of derivatization and showed that successful immobilization had taken place. Surfaces were imaged with atomic force microscopy to determine the uniformity of the heparin layer as well as its(More)
A nanoscale composite sensitizer composed of CuS and CdS quantum dots (QDs) was prepared by a simple but effective layer-by-layer reaction between a metal cation (Cu(2+) or Cd(2+)) and a sulfide anion (S(2-)). The as-prepared composite CuS/CdS QD sensitizer displayed an enhanced photon-to-current conversion over the sensitizing range of the visible spectrum(More)