• Korean Journal of Materials Research
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• v.29 no.5
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• pp.311-316
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• 2019

Transparent conducting electrodes are essential components in various optoelectrical devices. Although indium tin oxide thin films have been widely used for transparent conducting electrodes, silver nanowire network is a promising alternative to indium tin oxide thin films owing to its lower processing cost and greater suitability for flexible device application. In order to widen the application of silver nanowire network, the electrical conductance has to be improved while maintaining high optical transparency. In this study, we report the enhancement of the electrical conductance of silver nanowire network transparent electrodes by copper electrodeposition on the silver nanowire networks. The electrodeposited copper lowered the sheet resistance of the silver nanowire networks from $21.9{\Omega}{\square}$ to $12.6{\Omega}{\square}$. We perform detailed X-ray diffraction analysis revealing the effect of the amount of electrodeposited copper-shell on the sheet resistance of the core-shell(silver/copper) nanowire network transparent electrodes. From the relationship between the cross-sectional area of the copper-shell and the sheet resistance of the transparent electrodes, we deduce the electrical resistivity of electrodeposited copper to be approximately 4.5 times that of copper bulk.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.291-294
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• 2011

We studies a model for management of pepper anthracnose based covering method and spraying system in field. 1. Among 82 organic fungicides, 42 materials showed most effective inhibition against mycelia growth of the Colletotrichum acutatum in vitro. 23 formulated biocontrol agents were chosen to control the disease from 42 biocontrol agents in greenhouse. In the end, five kinds (2 plant extracts, 2 biopesiticides, 1 Bordeaux mixture) were selected from 23 materials in the field. 2. The mulching materials of bed covering in fruit season were thin non-woven fabric sheet and black plastic. The use of a fabric sheet was reduced the spread of anthracnose as compared to the plastic covering. 3. The application with the chosen materials was reduced 34% of anthracnose for 7 times sprays to planting 70 days as compared to the untreated control. In yield, nonwoven fabric sheet with formulated biopesticides was increased 17% than black plastic. 4. This result indicated that the developed biocontrol strategy could be an effective and economic crop protection system in organic pepper cultivation field.

• Journal of the Korean institute of surface engineering
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• v.32 no.3
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• pp.433-439
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• 1999

In this study, the diffusion barrier properties of $1000\AA$ thick molybdenum compounds (Mox=1-5 Si) were investigated using sheet resistance measurements, X-ray diffractometry (XRD), and Rutherford back scattering spectrometry (RBS). Each barrier material was deposited by the de and rf magnetron co-sputtering of Mo and Si, respectively, and annealed at $500-700^{\circ}C$ for 30 min in vacuum. Each barrier material was failed at low temperatures due to Cu diffusion through grain boundaries and defects of barrier thin films or through the reaction of Cu with Si within Mo-barrier thin films. It was found that Mo rich thin films were less effective than Si rich films to Cu penetration activating Cu reaction with the substrate at a temperature higher than $500^{\circ}C$.

• Transactions of Materials Processing
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• v.21 no.6
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• pp.348-353
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• 2012

Micro-drawn parts have received wider acceptance as products become smaller and more precise. The subject of this study was the deformation characteristics of ultra thin sheet metal in micro drawing of a rectangular shaped part. The influence of drawing speed and blank holding force on the product quality was investigated in micro-drawing of ultra thin sheet of beryllium copper (C1720) alloy. The specimen had a diameter of 4.8 mm and a thickness of $50{\mu}m$. Experiments were carried out in which, different blank holding force and drawing speed were considered. The product quality was evaluated by measuring the thickness and hardness along two specified directions, namely, the side and diagonal directions. The distribution of the thickness strain showed severe thinning especially around the punch radius in both directions. In the diagonal direction, thickening occurred in the flange area due to the axi-symmetric drawing mode. The increase of blank holding force and/or drawing speed was found to cause severe thinning around the punch radius. The blank holding force had a greater effect on thinning of the product than the drawing speed.

• Transactions on Electrical and Electronic Materials
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• v.13 no.4
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• pp.208-211
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• 2012

In the present study, a ZnO thin film, as a buffer layer of ITO (indium tin oxide) film was deposited on glass substrates by RF magnetron sputtering at low temperature of $150^{\circ}C$. In order to estimate the optical characteristics and compare with the experimental results in Glass/ZnO(100 nm)/ITO(35 nm) multilayered film, the simulation program, EMP (Essential Macleod Program) was adopted. The sheet resistance and optical transmittance of the films were measured using the four-point probe method and spectrophotometer, respectively. From X-ray diffraction patterns, all the films deposited at $150^{\circ}C$ demonstrated only the amorphous phase. Optical transmittance was the highest at a ZnO thickness of 100 nm. The ITO(35 nm)/ZnO(100 nm) film exhibits an optical transmittance of >92% at 550 nm. The multilayered film showed an electrical sheet resistance of 407 ${\Omega}/sq.$, which is significantly better than that of a single-layer ITO film without a ZnO buffer layer (815 ${\Omega}/sq.$).

• Korean Journal of Metals and Materials
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• v.49 no.2
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• pp.187-191
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• 2011

In order to obtain a suitable back contacting electrode for $Cu(InGa)Se_2$-based photovoltaic devices, a molybdenum thin film was deposited using a chemical vapor transport (CVT) during the hydrogen reduction of $MoO_3$ powder. A $MoO_2$ thin film was successfully deposited on substrates by using the CVT of volatile $MoO_3(OH)_2$ at $550^{\circ}C$ for 60 min in a $H_2$ atmosphere. The Mo thin film was obtained by reduction of $MoO_2$ at $650^{\circ}C$ in a $H_2$ atmosphere. The Mo thin film on the substrate presented a low sheet resistance of approximately $1{\Omega}/sq$.

• Journal of the Korean Society for Heat Treatment
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• v.25 no.3
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• pp.134-137
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• 2012

We have considered the effect of electron irradiation energy of 300, 600 and 900 eV on structural, electrical and optical properties of $In_2O_3$ films prepared with RF magnetron sputtering. In this study, the thin film crystallization, optical transmittance and sheet resistance are dependent on the electron's irradiation energy. The electron irradiated $In_2O_3$ films at 900 eV are grown as a hexagonal wurtzite phase. The sheet resistance decreases with a increase in electron irradiation energy and $In_2O_3$ film irradiated at 900 eV shows the lowest sheet resistance of $110{\Omega}/{\Box}$. The optical transmittance of $In_2O_3$ films in a visible wave length region also depends on the electron irradiation energy. The film that at 900 eV shows the higher figure of merit than another films prepared in this study.

• Korean Journal of Materials Research
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• v.31 no.3
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• pp.150-155
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• 2021

Zinc oxide (ZnO) based transparent conducting oxides (TCO) thin films, are used in many applications such as solar cells, flat panel displays, and LEDs due to their wide bandgap nature and excellent electrical properties. In the present work, fluorine and aluminium-doped ZnO targets are prepared and thin films are deposited on soda-lime glass substrate using a RF magnetron sputtering unit. The aluminium concentration is fixed at 2 wt%, and the fluorine concentration is adjusted between 0 to 2.0 wt% with five different concentrations, namely, Al2ZnO98(AZO), F0.5AZO97.5(FAZO1), F1AZO97(FAZO2), F1.5AZO96.5(FAZO3), and F2AZO96(FAZO4). Thin films are deposited with an RF power of 40 W and working pressure of 5 m Torr at 270 ℃. The morphological analysis performed for the thin film reveals that surface roughness decreases in FAZO1 and FAZO2 samples when doped with a small amount of fluorine. Further, optical and electrical properties measured for FAZO1 sample show average optical transmissions of over 89 % in the visible region and 82.5 % in the infrared region, followed by low resistivity and sheet resistance of 3.59 × 10-4 Ωcm and 5.52 Ω/sq, respectively. In future, these thin films with excellent optoelectronic properties can be used for thin-film solar cell and other optoelectronics applications.

• Journal of Welding and Joining
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• v.16 no.5
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• pp.86-92
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• 1998

High speed wire seam weldability of tin coated thin gage sheet steels was investigated. Thickness and coating weight ranges of the test materials were 0.21~0.35mm and 1.1/1.1~2.8/11.2g/$m^2$, respectively. Test results indicated that the surface roughness value, Rz decreased as increasing the coating weight. The Rz was thought to be one of the important factors to influence the optimum welding condition range, $\triangle$Q. The $\triangle$Q showed close relationship with welding conditions such as welding pressure and travel speed. Higher welding pressure widened the $\triangle$Q while higher travel speed reduced the $\triangle$Q value. Results also demonstrated that tin coating weight should be optimized based on the weldability or the serviceability after welding. At th HAZ of sheet materials with thinner coating layer, tin depleted zone was produced since molten film of the coating material on the base metal agglomerated by the surface tension, which could result in reducing the corrosion resistance of the HAZ in the service environment.

• Korean Journal of Metals and Materials
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• v.50 no.7
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• pp.545-548
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• 2012

The optical and electronic properties of Indium Tin Oxide (ITO) thin films deposited on a RF-plasma treated glass substrate were investigated by X-Ray Photoelectron Spectroscopy (XPS), Ultra-violet Photoelectron Spectroscopy (UPS), Reflected Electron Energy Loss Spectroscopy (REELS). The modification of glass substrates was carried out by varying the time of the plasma surface treatment in an oxygen atmosphere. The focus of this research was to examine how the optical and electronic properties of ITO thin films change with the plasma treatment time. The surface energy increased since the carbon bonds were removed from the surface after the glass substrate received the surface treatment. The ITO thin films produced on the glass substrate with surface treatment showed that the high optical transmittance was approximately 85%. The measured band gap energy was as high as 3.23 eV when the plasma treatment time was 60 s and the work function after the treatment was increased by 0.5 eV in comparison to that before the treatment of 60 s. The ITO thin film exhibited an excellent sheet resistance of $2.79{\Omega}/{\Box}$. We found that the optical and electronic properties of ITO thin films can be improved by RF-plasma surface treatment.