• Journal of the Korean institute of surface engineering
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• v.50 no.2
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• pp.72-84
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• 2017

In this work, electrophoretic paint (E-paint) was deposited on AZ31 Mg alloy after four different surface pretreatments: knife abrading, SiC paper abrading, deionized (DI) water immersion and NaOH immersion. The deposition process of E-paint was studied by analyses of voltage-time and current-time curves, amount of deposited paint, current efficiency and surface oxide film resistance and the adhesion of E-paint was examined by tape test before and after immersion in DI water for 500 h at $40$^{\circ}C$. It was found that the induction time for the deposition, the amount of deposited paint and the current efficiency are inversely proportional to the resistances of surface films prepared by different surface pretreatment methods. The electrophoretic painting showed longer inductance time, larger amount of deposited paint and higher current efficiency on the highly conducting surfaces, such as knife-abraded and SiC-abraded surfaces than on the less conducting surfaces, such as DI water-immersed and NaOH-immersed samples. Excellent adhesion was observed on the E-paintings deposited onto knife-abraded and SiC-abraded AZ31 Mg alloy samplesSiC-abraded AZ31 Mg alloy samples.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.9
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• pp.818-824
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• 2008

The Separated Pulsed Laser Deposition (SPLD) technique uses two chambers that are separated by a conic metallic wall with a central orifice. The pressures of ablation chamber and deposition chamber were controlled by the differential vacuum system. We deposited zinc oxide (ZnO) thin films by SPLD method to obtain high quality thin films. When the bias voltage of +500 V was applied between a substrate and an orifice, the ZnO thin film was deposited efficiently. The deposited ZnO thin film at ablation chamber gas pressure of Ar 5 mTorr showed the sharpest ultraviolet absorption edge indicatory the band gap of about 3.1 eV. ZnO thin films were deposited using effect of electric and magnetic fields in the SPLD method. E${\times}$B drift happened by an electric fields and a magnetic fields, activated plasma plume, as a result the film surface became very smooth. When the bias voltage of +500 V and magnet of 0,1 T were applied the ZnO thin films surface state showed high quality. Grain size was 41.99 nm and RMS was 0.84 nm.

• Journal of the Korean Society of Clothing and Textiles
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• v.6 no.2
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• pp.33-40
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• 1982

The removal and redeposition of particulate soil occur simultaneously during the washing process. In order to investigate variables which affect on the redeposition of particulate soil, cotton lawn was soiled in the ion oxide black suspension using Launder-O meter. The amount of deposited soil was estimated by means of the spectrometric analysis of iron on the fabric after soiled. The results are as follows: 1. The presence of surfactants b suspension decreased the deposition of particulate soil and the most effective surfactant was soap and the descending order was NaDBS>CTAB>PONPE. 2. The influnce of temperature on soil deposition was considerable, soil deposition was gradually increased with elevating temperature in ionic surfactants solution such as NaDBS and CTAB but that was decreased above $40^{\circ}C$ in nonionic surfactant solution. 3. The tendency of soil deposition was dwindled by adding electrolytes especially in case of polyvalent anions. 4. From the results of the experiments redeposition of particulate soil was related with suspending power of surfactants and was influenced by factors varing zeta potential.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.240-241
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• 2007

In general, high temperature superconducting coated conductors have intermediary buffers layer consisting of seed, diffusion barrier and cap layers. Simplification of the oxide materials buffer architecture in the fabrication of high temperature superconducting coated conductors is required because the deposition of multi-layers buffer architecture leads to a longer manufacturing time and a higher cost process of coated conductors. Thus, single buffer layer deposition seems to be important for practical coated conductor manufacturing process. In this study, a single gradient layered buffer deposition process of YZO for low cost coated conductors has been tried using DC reactive sputtering technique. About several thick YZO gradient single buffer layers deposited by DC co-sputtering process were found to act as a diffusion layer.

• Journal of the Korean Electrochemical Society
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• v.3 no.2
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• pp.115-120
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• 2000

All solid-state thin film micro-batteries consisting of lithium metal anode, an amorphous LiPON electrolyte and cathode of vanadium oxide have been fabricated and characterized, which were fabricated with cell structure of $Li/LiPON/V_2O_5Pt$. The effect of various oxygen partial pressure on the electrochemical properties of vanadium oxide thin films formed by d.c. reactive sputtering deposition were investigated. The vanadium oxide thin film with deposition condition of $20\%\;O_2/Ar$ ratio showed good cycling behavior. In in-siか process, the LiPON electrolyte was deposited on the $V_2O_5$ films without breaking vacuum by r.f. magnetron sputtering at room temperature. After deposition of the amorphous LiPON, the Li metal films were grown by a thermal evaporator in a dry room. The charge-discharge cycle measurements as a function of current density and voltage variation revealed that the $Li/LiPON/V_2O_5$ thin film had excellent rechargeable properly when current density was $7{\mu}A/cm^2$. and cut-off voltage was between 3.6 and 2.7V In practical experiment, a stopwatch ran on this $Li/LiPON/V_2O_5$ thin film micro-battery. This result means that thin film micro-battery fabricated by in-siか process is a promising for power source for electronic devices.

• Journal of the Korean Electrochemical Society
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• v.12 no.1
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• pp.81-87
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• 2009

An indium-tin oxide (ITO) coated spinel manganese oxide (${LiMn_2}{O_4}$, LMO) is prepared and its high-temperature ($55^{\circ}C$) cycle performance and rate capability are examined. A severe electrolyte decomposition and film deposition is observed on the un-coated ${LiMn_2}{O_4}$ cathode, which leads to a significant electrode polarization and capacity fading. Such an electrode polarization is, however, greatly reduced for the ITO-coated (> 2 mol%) LMO cathode, which leads to an improved cycle performance. This can be rationalized by a suppression of electrolyte decomposition, which is in turn indebted to a decrease in the direct contact area between LMO and electrolyte. The suppression of film deposition on the ITO-coated LMO cathode is confirmed by infra-red spectroscopy. The rate capability is also improved by the surface coating, which may be resulted from a suppression of resistive film deposition and high electric conductivity of ITO itself.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.9
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• pp.931-935
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• 2012

In this study, we fabricate and investigate low-temperature solid oxide fuel cells with a ceramic substrate/porous metal/ceramic/porous metal structure. To realize low-temperature operation in solid oxide fuel cells, the membrane should be fabricated to have a thickness of the order of a few hundreds nanometers to minimize IR loss. Yttrium-doped barium zirconate (BYZ), a proton conductor, was used as the electrolyte. We deposited a 350-nm-thick Pt (anode) layer on a porous substrate by sputter deposition. We also deposited a 1-${\mu}m$-thick BYZ layer on the Pt anode using pulsed laser deposition (PLD). Finally, we deposited a 200-nm-thick Pt (cathode) layer on the BYZ electrolyte by sputter deposition. The open circuit voltage (OCV) is 0.806 V, and the maximum power density is 11.9 mW/$cm^2$ at $350^{\circ}C$. Even though a fully dense electrolyte is deposited via PLD, a cross-sectional transmission electron microscopy (TEM) image reveals many voids and defects.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.742-748
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• 2005

Transparent conductive indium-tin oxide (ITO) films are widely used as transparent electrodes for flat panel displays. Many of the ITO films for practical use have been prepared by magnetron sputtering, chemical vapor deposition, electron beam evaporation, etc. An oxide target composed of 10 wt% $SnO_2$ and 90 wt% $In_2O_3$ has been deposited onto polycyclic olefin polymer (POP) substrate by electron beam evaporation. POP has a higher glass transition temperature ($Tg=330^{\circ}C$) than other conventional polymers. In this study, the effects of substrate temperature and the $O_2$ introduction flow rate were investigated in terms of physical, electrical and optical properties of deposited ITO films. We investigated the effects of processing variables such as substrate temperature and the oxygen introduction flow rate. The best electrical and optical properties of deposited ITO films obtained from this study were electrical resistivity value of ${\rho}=1.78{\times}10^{-3}{\Omega}{\cdot}cm$ and optical transmittance of about 85% at 8 sccm (Standard Cubic Centimeter per Minute) $O_2$ introduction flow rate, $5{\AA}/sec$ deposition rate, $1000{\AA}$ deposited ITO thickness and $200^{\circ}C$ substrate temperature.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.418.1-418.1
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• 2016

Atomic layer deposition (ALD)를 이용하여 증착된 aluminum oxide ($Al_2O_3$)는 우수한 패시베이션 특성을 가지고 있다. $Al_2O_3$ 박막은 많은 수소를 가지고 있기 때문에 화학적 패시베이션에 의한 실리콘 표면을 패시베이션 할 수 있다. 또한 $Al_2O_3$는 강한 고정전하를 가져 전계 효과 패시베이션을 할 수 있다. 따라서 $Al_2O_3$ 박막을 태양전지에 적용할 경우 높은 효율을 기대할 수 있다. 실리콘 태양전지를 제작하기 위해 소성공정(> $800^{\circ}C$)은 필수이다. $Al_2O_3$ 박막은 많은 수소를 가지고 있기 때문에 소성공정시 수소가스를 방출하여 $Al_2O_3$ 박막에 블리스터를 형성시킨다. 이 블리스터는 $Al_2O_3/Si$ 계면에서 발생하여 패시베이션 특성을 감소시킨다. 블리스터를 억제하기 위해 수소의 양을 조절할 필요가 있다. 이 실험에서는 plasma-assisted atomic layer deposition (PAALD)으로 $Al_2O_3$를 증착하였다. PAALD의 RF power를 200 W부터 800 W까지 조절하여 $Al_2O_3$ 막에 포함되는 OH의 농도를 조절하였다. $Al_2O_3$ 박막에 포함되는 OH 농도는 X-ray Photoelectron Spectroscopy (XPS)를 이용하여 분석하였다. 열처리공정 후, 화학적 패시베이션에 의한 유효 반송자 수명 (${\tau}_{eff}$) 향상이 나타났다 소성공정 후 블리스터가 형성되지 않는 조건에서 화학적 패시베이션과 전계 효과 패시베이션에 의해 ${\tau}_{eff}$가 증가하였다. 블리스터가 형성되었을 때 기존 논문들과 같이 패시베이션 특성이 감소하였다. 패시베이션 특성의 감소는 블리스터에 의한 화학적 패시베이션의 감소 때문이며 전계 효과 패시베이션은 오히려 증가하였다. 이를 통해 고온에서 열안정성을 갖는 $Al_2O_3$ 박막을 만들었으며 블리스터가 형성되지 않았고 패시베이션 특성이 증가하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.8
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• pp.584-592
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• 2012

Room temperature powder spray in vacuum process, so called Aerosol deposition (AD) is a room temperature (RT) process to fabricate thick and dense ceramic films, based on collision of solid ceramic particles. This technique can provide crack-free dense thin and thick films with thicknesses ranging from sub micrometer to several hundred micrometers with very fast deposition rates at RT. In addition, this technique is using solid particles to form the ceramic films at RT, thus there is few limitation of the substrate and easy to control the compositions of the films. In this article, we review the progress made in synthesis of piezoelectric thin/thick films, multi-layer structures, NTC thermistor thin/thick films, oxide electrode thin films for actuators or sensor applications by AD at Korea Institute of Materials Science (KIMS) during the last 4 years.