• Archives of Pharmacal Research
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• v.11 no.1
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• pp.56-60
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• 1988

A thin layer flow cell with cell volume of $8\;{\mu}{\ell}$ was constructed. Diffusion currents of ascorbic acid was directly proportional to the 1/3 power of volume flow rates. A linear dynamic range was obtained at the concentration range between $10^{-7}\;M\;and\;10^{-4}\;M$ of ascorbic acid with a detection limit of $10^{-8}\;M$. Ascorbic acid in the multivitamin product was amperometrically determined at TLFC after simply dissolving mg range ground product in $100m{\ell}$ of pH 7.0 phosphate buffer.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.423-427
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• 1999

Electroplating of 80%Ni permalloy thin plate for magnetic core materials. was studied The convected flow of electrolyte was used for stirring methode. The current density could be increased up to 250mA/$\textrm{cm}^2$ by flow cell. The composition of electroplated layer with vespect to current density and flow rate was investigated and experimental equation to predict the composition was made. How cell yielded more uniform thickness distribution than paddle cell did. The composition distribution was also studied. The thickness was the most important factor to the permeability. The permeability of 5$\mu\textrm{m}$plated permalloy was over 2000 at 1 MHz.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.426.1-426.1
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• 2016

We report high work function Aluminum doped zinc oxide (AZO) films as insertion layer as a function of O2 flow rate between transparent conducting oxides (TCO) and hydrogenated amorphous silicon oxide (a-SiOx:H) layer to improve open circuit voltage (Voc) and fill factor (FF) for high efficiency thin film solar cell. However, amorphous silicon (a-Si:H) solar cells exhibit poor fill factors due to a Schottky barrier like impedance at the interface between a-SiOx:H windows and TCO. The impedance is caused by an increasing mismatch between the work function of TCO and that of p-type a-SiOx:H. In this study, we report on the silicon thin film solar cell by using as insertion layer of O2 reactive AZO films between TCO and p-type a-SiOx:H. Significant efficiency enhancement was demonstrated by using high work-function layers (4.95 eV at O2=2 sccm) for engineering the work function at the key interfaces to raise FF as well as Voc. Therefore, we can be obtained the conversion efficiency of 7 % at 13mA/cm2 of the current density (Jsc) and 63.35 % of FF.

• Corrosion Science and Technology
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• v.6 no.6
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• pp.291-296
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• 2007

The corrosion of metals and alloys in flowing liquids can be classified into uniform corrosion and localized corrosion which may be categorized as follows. (1) Localized corrosion of the erosion-corrosion type: the protective oxide layer is assumed to be removed from the metal surface by shear stress or turbulence of the fluid flow. A macro-cell may be defined as a situation in which the bare surface is the macro-anode and the other surface covered with the oxide layer is the macro-cathode. (2) Localized corrosion of the differential flow-velocity corrosion type: at a location of lower fluid velocity, a thin and coarse oxide layer with poor protective qualities may be produced because of an insufficient supply of oxygen. A macro-cell may be defined as a situation in which this surface is the macro-anode and the other surface covered with a dense and stable oxide layer is the macro-cathode. (3) Localized corrosion of the active/passive-cell type: on a metal surface a macro-cell may be defined as a situation in which a part of it is in a passivation state and another in an active dissolution state. This situation may arise from differences in temperature as well as in the supply of the dissolved oxygen. Compared to uniform corrosion, localized corrosion tends to involve a higher wall thinning rate (corrosion rate) due to the macro-cell current as well as to the ratio of the surface area of the macro-anode to that of the macro-cathode, which may be rationalized using potential vs. current density diagrams. The three types of localized corrosion described above can be reproduced in a Jet-in-slit test by changing the flow direction of the test liquid and arranging environmental conditions in an appropriate manner.

• Transactions on Electrical and Electronic Materials
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• v.10 no.3
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• pp.75-79
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• 2009

An intrinsic silicon thin film passivation layer is deposited by the microwave remote-plasma enhanced chemical vapor deposition at temperature of $175^{\circ}C$ and various gas ratios for solar cell applications. The good quality amorphous silicon films were formed at silane $(SiH_4)$ gas flow rates above 15 seem. The highest effective carrier lifetime was obtained at the $SiH_4$, flow rate of 20 seem and the value was about 3 times higher compared with the bulk lifetime of 5.6 ${\mu}s$ at a fixed injection level of ${\Delta}n\;=\;5{\times}10^{14}\;cm^{-3}$. An annealing treatment was performed and the carrier life times were increased approximately 5 times compared with the bulk lifetime. The optimal annealing temperature and time were obtained at 250 $^{\circ}C$ and 60 sec respectively. This indicates that the combination of the deposition of an amorphous thin film at a low temperature and the annealing treatment contributes to the excellent surface and bulk passivation.

• Current Photovoltaic Research
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• v.3 no.4
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• pp.130-134
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• 2015

The high efficiency cell research processes through the KF post deposition treatment (PDT) of the $Cu(In,Ga)Se_2(CIGS)$ thin film has been very actively progress. In this study, it CIGS thin film deposition process when KF PDT 300 to the processing temperature, 350, $400^{\circ}C$ changed to soda-lime glass (SLG) efficiency of the CIGS thin film characteristics, and solar cell according to Na presence of diffusion from the substrate the effects were analyzed. As a result, the lower the temperature of KF PDT and serves to interrupt the flow of current K-CIGS layer is not removed from the reaction surface, FF and photocurrent is decreased significantly. Blocking of the Na diffusion from the glass substrate is significantly increased while the optical voltage, photocurrent and FF is a low temperature (300, $350^{\circ}C$) in the greatly reduced, and in $400^{\circ}C$ tend to reduce fine. It is the presence of Na in CIGS thin film by electron-induced degradation of the microstructure of CIGS thin film is expected to have a significant impact on increasing the hole recombination rate a reaction layer is formed of the K elements in the CIGS thin film surface.

• Korean Journal of Materials Research
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• v.20 no.4
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• pp.187-193
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• 2010

Chromium nitride (CrN) samples with two different layer structures (multilayer and single layer) were coated on bipolar plates of polymer electrolyte membrane fuel cells (PEMFC) using the reactive sputtering method. The effects with respect to layer structure on corrosion resistance and overall cell performance were investigated. A continuous and thin chromium nitride layer ($Cr_{0.48}\;N_{0.52}$) was formed on the surface of the SUS 316L when the nitrogen flow rate was 10 sccm. The electrochemical stability of the coated layers was examined using the potentiodynamic and potentiostatic methods in the simulated corrosive circumstances of the PEMFC under $80^{\circ}C$. Interfacial contact resistance (ICR) between the CrN coated sample and the gas diffusion layer was measured by using Wang's method. A single cell performance test was also conducted. The test results showed that CrN coated SUS316L with multilayer structure had excellent corrosion resistance compared to single layer structures and single cell performance results with $25\;cm^2$ in effective area also showed the same tendency. The difference of the electrochemical properties between the single and multilayer samples was attributed to the Cr interlayer layer, which improved the corrosion resistance. Because the coating layer was damaged by pinholes, the Cr layer prevented the penetration of corrosive media into the substrate. Therefore, the CrN with a multilayer structure is an effective coating method to increase the corrosion resistance and to decrease the ICR for metallic bipolar plates in PEMFC.

• Analytical Science and Technology
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• v.17 no.6
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• pp.470-475
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• 2004

The mercury film thin layer flow cell (MFTLFC) which yielded the highest sensitivity for the electrochemical reduction of doxorubicin was constructed by coating the glassy carbon working electrode (GCE; $A=0.208cm^2$) with $5{\mu}L$ of HgO coating solution (0.5% HgO + 0.25% polystyrene/cyclohexanone) and subsequently followed by applying a potential of -0.40 V for 300 sec in the flow stream of an acetate buffer of pH 4.5. The voltammogram of doxorubicin reached the diffusion current plateau at -0.53 V vs. a Ag/AgCl (3 M NaCl) in the MFTLFC. The diffusion current (Id) of doxorubicin at the MFTLFC was 1.7 times greater than the Id obtained at the TLFC employing a bare glassy carbon working electrode. When the peak areas (electric charge) were plotted vs. concentrations of standard anthracyclines, the calibration factors of doxorubicin and daunorubicin were $1.12{\times}10^8{\mu}C/M$ (coefficient of determination; $R^2$: 0.969) and $0.98{\times}10^8{\mu}C/M$> ($R^2$: 0.999), respectively in the concentration range between $1.0{\times}10^{-8}M$ and $1.0{\times}10^{-6}M$.

• Korean Journal of Materials Research
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• v.11 no.8
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• pp.671-678
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• 2001

All solid-state thin film micro supercapacitor, which consists of $RuO_2$/LiPON/$RuO_2$ multi layer structure, was fabricated on Pt/Ti/Si substrate using a $RuO_2$ electrode. Bottom $RuO_2$ electrode was grown by dc reactive sputtering system with increasing $O_2/[Ar+O_2]$ ratio at room temperature, and a LiPON electrolyte film was subsequently deposited on the bottom $RuO_2$ electrode at pure nitrogen ambient by rf reactive sputtering system. Room temperature charge-discharge measurements based on a symmetric $RuO_2$/LiPON/$RuO_2$ structure clearly demonstrates the cyclibility dependence on the microstructure of the $RuO_2$ electrode. Using both glancing angle x-ray diffraction (GXRD) and transmission electron microscopy (TEM) analysis, it was found that the microstructure of the $RuO_2$ electrode was dependent on the oxygen flow ratio. In addition, x- ray photoelectron spectroscopy(XPS) examination shows that the Ru-O binding energy is affected by increasing oxygen flow ratio. Furthermore, TEM and AES depth profile analysis after cycling demonstrates that the interface layer formed by interfacial reaction between LiPON and $RuO_2$ act as a main factor in the degradation of the cyclibility of the thin film micro-supercapacitor.

• Journal of the Korean Ceramic Society
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• v.47 no.1
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• pp.82-85
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• 2010

Recently, thin film processes for oxides and metal deposition, such as physical vapor deposition (PVD) and chemical vapor deposition (CVD), have been widely adapted to fabricate solid oxide fuel cells (SOFCs). In this paper, we presented two research area of the use of such techniques. Gadolinium doped ceria (GDC) showed high ionic conductivity and could guarantee operation at low temperature. But the electron conductivity at low oxygen partial pressure and the weak mechanical property have been significant problems. To solve these issues, we coated GDC electrolyte with a nano scale yittria-doped stabilized zirconium (YSZ) layer via atomic layer deposition (ALD). We expected that the thin YSZ layer could have functions of electron blocking and preventing ceria from the reduction atmosphere. Yittria-doped barium zirconium (BYZ) has several orders higher proton conductivity than oxide ion conductor as YSZ and also has relatively high chemical stability. The fabrication processes of BYZ is very sophisticated, especially the synthesis of thin-film BYZ. We discussed the detailed fabrication processes of BYZ as well as the deposition of electrode. This paper discusses possible cell structure and process flow to accommodate such films.