• Journal of Powder Materials
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• v.18 no.6
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• pp.532-537
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• 2011

Thermally stable $TiO_2$/Pt/$SiO_2$ core-shell nanocatalyst has been synthesized by chemical processes. Citrated capped Pt nanoparticles were deposited on amine functionalized silica produced by Stober process. Ultrathin layer of titania was coated on Pt/$SiO_2$ for preventing sintering of the metal nanoparticles at high temperatures. Thermal stability of the metal-oxide hybrid catalyst was demonstrated heating the sample up to $600^{\circ}C$ in air and by investigating the morphology and integrity of the structure by transmission electron spectroscopy. The surface analysis of the constituent elements was performed by X-ray photoemission spectroscopy. The catalytic activity of the hybrid catalysts was investigated by CO oxidation reaction with oxygen as a model reaction.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.181.2-181.2
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• 2016

OLED 소자는 발광 방향에 따라 Bottom Emission 방식과 Top Emission 방식으로 나뉜다. 이 중 대면적 OLED TV 적용에 개구율이 더 높은 Top Emission방식을 선호하는 추세이다. 높은 개구율을 가진 Top Emission OLED소자를 위해서는 투명하고 전도성이 높은 캐소드가 중요하다. 본 연구에서는 Themal Evaporation 시스템을 이용하여 증착한 $SnO_2/Ag-Pd-Cu(APC)/SnO_2$ hybrid 전극의 특성을 연구하고 Oxide/Metal/Oxide(OMO) hybrid 박막의 bending mechanism을 제시하였다. base pressure는 $1{\times}10^{-6}Torr$로 고정하고 $SnO_2$ 박막은 0.34A / 0.32V, APC 박막은 0.46A / 0.40V의 power로 성막하였다. APC와 $SnO_2$의 두께를 변수로 OMO 전극을 제작하였고 그 전기적, 광학적 특성을 Hall measurement, UV/Visible spectroscopy을 이용하여 분석하고 Figure of merit 값을 바탕으로 최적 두께를 설정하였다. UPS(Ultraviolet Photoelectron Spectroscopy) 분석으로 $SnO_2/APC/SnO_2$ 전극의 일함수을 통해 투명 cathode로 쓰였을 때 $SnO_2$ 층이 buffer layer역할을 함을 확인하였다. XPS(X-ray photoelectron spectroscopy)를 이용하여 정성분석과 정량분석을 하였고 OMO hybrid 전극의 bending mechanism 연구를 위해 다양한 bending test (Inner/Outer dynamic fatigue test, twisting test, rolling test)를 진행하였다. 물리적 힘이 가해진 OMO hybrid 전극의 표면과 구조는 FE-SEM(Field Emission Scanning Electron Microscope) 분석을 통해서 확인할 수 있었다.

• Journal of the Optical Society of Korea
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• v.20 no.6
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• pp.807-812
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• 2016

Transparent film heaters (TFHs) based on Joule heating are currently an active research area. However, TFHs based on an indium tin oxide (ITO) monolayer have a number of problems. For example, heating is concentrated in only part of the device. Also, heating efficiency is low because it has high sheet resistance ($R_s$). To address these problems, this study introduced hybrid layers of ITO/Ag/ITO deposited by magnetron sputtering, and the electrical, optical, and thermal properties were estimated for various thicknesses of the metal interlayer. The $R_s$ of ITO(40)/Ag/ITO(40 nm) hybrid TFHs were 5.33, 3.29 and $2.15{\Omega}/{\Box}$ for Ag thicknesses of 10, 15, and 20 nm, respectively, while the $R_s$ of an ITO monolayer (95 nm) was $59.58{\Omega}/{\Box}$. The maximum temperatures of these hybrid TFHs were 92, 131, and $145^{\circ}C$, respectively, under a voltage of 3 V. And that of the ITO monolayer was only $32^{\circ}C$. For the same total thickness of 95 nm, the heat generation rate (HGR) of the hybrid produced a temperature approximately $100^{\circ}C$ higher than the ITO monolayer. It was confirmed that the film with the lowest $R_s$ of the samples had the highest HGR for the same applied voltage. Overall, hybrid layers of ITO/Ag/ITO showed excellent performance for HGR, uniformity of heat distribution, and thermal response time.

• Carbon letters
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• v.25
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• pp.113-116
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• 2018

• Journal of the Korean Society for Precision Engineering
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• v.32 no.5
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• pp.497-497
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• 2015

• Journal of the Korean Applied Science and Technology
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• v.28 no.3
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• pp.329-334
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• 2011

The electrochemical performances of an asymmetric hybrid capacitor were investigated using $LiFePO_4$ as the positive electrode and active carbon fibers(ACF) as the negative electrode. The electrochemical behaviors of a nonaqueous hybrid capacitor were characterized by constant current charge/discharge test. The specific capacitance using $LiFePO_4$/ACF electrode turned out to be $0.87F/cm^2$ and the unit cell showed excellent cycling performance. This hybrid capacitor was able to deliver a specific energy as high as 178 Wh/kg at a specific power of 1,068 W/kg.

• Journal of Electrochemical Science and Technology
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• v.9 no.2
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• pp.93-98
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• 2018

$MnO_2$, a metal oxide used as an electrode material in electrochemical capacitors (EDLCs), has been applied in binary oxide and conducting polymer hybrid electrodes to increase their stability and capacitance. We developed a method for electrodepositing Mn-Ni oxide/PANI, Mn-Ni oxide/PEDOT, and Mn-Ni-Ru oxide/PEDOT films on carbon paper in a single step using a mixed bath. Mn-Ni oxide/PEDOT and Mn-Ni-Ru oxide/PEDOT electrodes used in an electro-osmotic pump (EOP) have shown better efficiency compared to Mn-Ni oxide and Mn-Ni oxide/PANI electrodes through testing in water as a pumping solution. EOP using a Mn-Ni-Ru oxide/PEDOT electrode was also tested in a 0.5 mM $Li_2SO_4$ solution as a pumping solution to confirm the effect of the $Li^+$ insertion/de-insertion reaction of Ruthenium oxide on the EOP. Experimental results show that the flow rate increases with the increase in current in a 0.5 mM $Li_2SO_4$ solution compared to that obtained when water was used as a pumping solution.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.05a
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• pp.215-225
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• 2002

In order to enhance the thermal stability of binder materials of bonded type solid lubricants, several combinations of metal-alkoxide based sol-gel materials such as methyltrimethoxysilane(MTMOS), $titaniumisopropoxide(Ti(Opr^{j})_{4})$, $zirconiumisopropoxide(Zr(Opr^{j})_{4})$ and $aluminumbutoxide(Al(Obu^{t})_{4})$ were chemically modified by epoxy-, acrylic- and fluoro-silane compounds, respectively, in this work. Friction and wear characteristics of these hybrid ceramic materials were tested with a micro tribe-tester where a reciprocating steel ball slid on a test material, and the tribological property was also evaluated with respect to both heat-curing temperature and tile time. Test results generally showed that hybrid ceramic materials modified by epoxy-silane compounds had a low friction compared to others. And the higher heat-curing temperature and the longer heat treatment time resulted in the higher friction and the lower wear. IR spectroscopic analyses revealed that it was caused mainly by the increased metal oxide content in hybrid ceramics when the heat-curing temperature was over $320^{\circ}C$.

• Tribology and Lubricants
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• v.18 no.5
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• pp.324-332
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• 2002

In order to enhance the thermal stability of binder materials of bonded type solid lubricants, several metal-alkoxide based sol-gel materials such as methyltrimethoxysilane(MTMOS), titaniumisopropoxide$(Ti(Opr^i)_4),$ zirconiumisopropoxide $(Zr(Opr^i)_4)$ and aluminumbutoxide$(Al(Obu^t)_4)$ were chemically modified by epoxy-, acrylic- and fluoro-silane compounds, respectively. Friction and wear characteristics of these hybrid ceramic materials were tested with a micro tribo-tester, and evaluated with respect to both heat-curing temperature and the time. Test results generally showed that hybrid ceramic materials modified by epoxy-silane compounds had a low friction compared to others. And the higher het-curing temperature and the longer heat treatment time resulted in the higher friction and the lower wear. IR spectroscopic analyses revealed that these results were caused mainly by the increased metal oxide content in hybrid ceramics when the heat-curing temperature was over $320^{\circ}C.$

• Korean Journal of Materials Research
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• v.24 no.10
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• pp.543-549
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• 2014

A zinc oxide (ZnO) hybrid structure was successfully fabricated on a glass substrate by metal organic chemical vapor deposition (MOCVD). In-situ growth of a multi-dimensional ZnO hybrid structure was achieved by adjusting the growth temperature to determine the morphologies of either film or nanorods without any catalysts such as Au, Cu, Co, or Sn. The ZnO hybrid structure was composed of one-dimensional (1D) nanorods grown continuously on the two-dimensional (2D) ZnO film. The ZnO film of 2D mode was grown at a relatively low temperature, whereas the ZnO nanorods of 1D mode were grown at a higher temperature. The change of the morphologies of these materials led to improvements of the electrical and optical properties. The ZnO hybrid structure was characterized using various analytical tools. Scanning electron microscopy (SEM) was used to determine the surface morphology of the nanorods, which had grown well on the thin film. The structural characteristics of the polycrystalline ZnO hybrid grown on amorphous glass substrate were investigated by X-ray diffraction (XRD). Hall-effect measurement and a four-point probe were used to characterize the electrical properties. The hybrid structure was shown to be very effective at improving the electrical and the optical properties, decreasing the sheet resistance and the reflectance, and increasing the transmittance via refractive index (RI) engineering. The ZnO hybrid structure grown by MOCVD is very promising for opto-electronic devices as Photoconductive UV Detectors, anti-reflection coatings (ARC), and transparent conductive oxides (TCO).