• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.7-12
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• 2013

Tin oxide thin-films have been widely applied in various fields of high-technology industries due to their excellent physical and electric properties. Those applications are found in various sensors, heating elements of windshield windows, solar cells, flat panel displays as tranparent electrodes. In this study, we conducted an experiment for the deposition of $SnO_2$ on glass of 2nd Gen. size for the effective development of large-scale backplanes. As deposition temperatures or flow rates of the $SnCl_4$ as a precursor changed, the thickness of tin oxide thin-films, their sheet resistances, transmittances, and hazes varied considerably.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.426.1-426.1
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• 2014

For high performance thin film solar cells, texturing surface, enhancing the optical absorptionpath, is pretty important. Textured ZnO:Al transparent oxide layer of high haze is commonly used in Si thin film solar cells. In this paper, novel deposition method for aluminum doped zinc oxide (ZnO:Al) on glass substrates is presented to improve the haze property. The broccoli structure of ZnO:Al layer was formed on chemically etched glass substrates, which showed high haze value on a wide wavelength range.The etching condition of the glass substrates can change not only the haze values of the ZnO:Al of in-situ growth but alsothe electrical and optical properties of the deposited ZnO:Al films.The etching mechanism of the glass substrate affecting on the surface morphology of the glass will be discussed, which resulted in variation of texture of ZnO:Al layer. The optical properties of substrate morphology were also analyzed with EDS and FTIR results. As a result, the high haze value of 85.4% was obtained in the wavelength range of 300 nm to 1100 nm. Furthermore, low sheet resistance of about 5~18 ohm/sq was achieved for different surface morphologies of the ZnO:Al films.

• Applied Chemistry for Engineering
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• v.20 no.6
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• pp.612-616
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• 2009

Transparent conductive oxide (TCO) films have been widely used in the field of flat panel display industry. Transparent conductive indium zinc oxide (IZO) thin films with excellent chemical stability have attracted much attention as an alternative material for indium tin oxide (ITO) films. In this study, using a $In_2O_3$ and ZnO powder mixture with a ratio of 90 : 10wt% as a target, IZO films were prepared on polynorbornene (PNB) substrates by electron beam evaporation. The effect of substrate temperature and $O_2$ introduction flow rate were investigated in terms of electrical and optical properties of deposited IZO films. The best electrical and optical properties we obtained from this study were sheet resistance value of $5.446{\times}10^2{\Omega}/{\boxempty}$ and optical transmittance of 87.4% at 550 nm at $O_2$ introduction flow rate of 4 sccm, deposition rate of $2{\AA}$/sec, thickness of 1000 $\AA$ and substrate temperature of $150^{\circ}C$.

• Fashion & Textile Research Journal
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• v.22 no.2
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• pp.233-239
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• 2020

We proposed a simple process of fabricating electroconductive textiles by coating conductive polymer PEDOT:PSS (Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)) on biocompatible PLA (Poly Lactic Acid) nanofiber web for application to smart healthcare. Electroconductive textiles were obtained by a drop-coating process using different amounts of PEDOT:PSS solutions., DMSO (dimethyl sulfoxide) was then used as an additive in the post-treatment process to improve conductivity. The surface morphology of the specimens was observed by FE-SEM. The chemical structures of the specimens were characterized using FTIR. The electrical properties (linear and sheet resistance) of the specimens were measured. The effect of the bending angles on the electrical properties was also investigated to confirm their applicability as wearable smart textiles. FE-SEM and FTIR analysis confirmed that the deposition of PEDOT:PSS on the PLA nanofiber web surface was successful. The conductivity of the PEDOT:PSS/PLA nanofiber web was enhanced up to 1.5 ml with an increasing amount of PEDOT:PSS solutions, but there was no significant difference at 2.0 ml. The optimum condition of PEDOT:PSS deposition was established to 1.5 ml. Even when the specimen coated with 1.5 ml was bent every 30°, the change in the electrical resistance values was still low within 3.7 Ω. It confirmed that stable electrical performance was maintained and proved the applicability as a flexible textile sensor.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.125-125
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• 2011

In this study, we investigated the electrical, optical, structural, and surface properties of indium zinc oxide (IZO)/Ag/IZO multilayer electrode grown by specially designed roll-to-roll sputtering system using the flexible substrate. By the continuous roll-to-roll sputtering of the bottom IZO, Ag, and top IZO layers at room temperature, they were able to fabricate a high quality IZO/Ag/IZO multilayer electrode. At optimized conditions, the bottom IZO layer (40 nm) was deposited on a flexible substrate. After deposition of the Bottom IZO layer, Ag layer was deposited onto the bottom IZO film as a function of DC power (200~500 W). Subsequently, the top IZO layer was deposited onto the Ag layer at identical deposition conditions to the bottom IZO layer (40 nm). We investigated the characteristics of IZO/Ag/IZO multilayer electrode as a function of Ag thickness. It was found that the electrical and optical properties of IZO/Ag/IZO multilayer electrode was mainly affected thickness of the Ag layer at optimized condition. In case of IZO/Ag/IZO multilayer electrode with the Ag power (350W), it exhibited a low sheet resistance of 7.1 ohm/square and a high transparency of 86.4%. Furthermore, we fabricated the touch screen panel using the IZO/Ag/IZO multilayer electrode, which demonstrate the possibility of the IZO/Ag/IZO multilayer electrode grown by roll-to-roll sputtering system as a transparent conducting layer in the touch screen panel.

• Korean Journal of Materials Research
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• v.20 no.10
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• pp.513-517
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• 2010

There have been many efforts to modify and improve the properties of functional thin films by hybridization with nano-sized materials. For the fabrication of electronic circuits, micro-patterning is a commonly used process. For photochemical metal-organic deposition, photoresist and dry etching are not necessary for microscale patterning. We obtained direct-patternable $SnO_2$ thin films using a photosensitive solution containing Ag nanoparticles and/or multi-wall carbon nanotubes (MWNTs). The optical transmittance of direct-patternable $SnO_2$ thin films decreased with introduction of nanomaterials due to optical absorption and optical scattering by Ag nanoparticles and MWNTs, respectively. The crystallinity of the $SnO_2$ thin films was not much affected by an incorporation of Ag nanoparticles and MWNTs. In the case of mixed incorporation with Ag nanoparticles and MWNTs, the sheet resistance of $SnO_2$ thin films decreased relative to incorporation of either single component. Valence band spectral analyses of the nano-hybridized $SnO_2$ thin films showed a relation between band structural change and electrical resistance. Direct-patterning of $SnO_2$ hybrid films with a line-width of 30 ${\mu}m$ was successfully performed without photoresist or dry etching. These results suggest that a micro-patterned system can be simply fabricated, and the electrical properties of $SnO_2$ films can be improved by incorporating Ag nanoparticles and MWNTs.

• Journal of the Korean Chemical Society
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• v.31 no.1
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• pp.102-109
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• 1987

Some characteristics of $SnO_2$ film which was deposited on a slide glass substrate, using dibutyl tin diacetate and oxygen, by the chemical vapor deposition were observed. The optimum condition for the preparation of the film was found to be at 420$^{\circ}C$ of substrate temperature for 20 min of deposition. Important optical, electrical, and structural features of the film were examined. It was found that the typical $SnO_2$ film on the untreated substrate was 4000${\AA}$ in thickness, transmitted 90% of the visible liglit, and provided 5800 ohms/${\square}$ of the sheet resistance. It was also found that the surface treatments of the slide glass by acid leaching were beneficial. The film structure was found to be a mixture of polycrystalline tetragonal stannic oxide confirmed by the X-ray diffraction and to be spherical fine grains concluded by the scanning electron microscopy.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.4
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• pp.935-938
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• 2010

Indium-tin-oxide (ITO) films show a low electrical resistance and high transmittance in the visible range of an optical spectrum. The transparent electrodes have to get resistivity and sheet resistance less than $1{\times}10^{-3}{\Omega}/cm$ and $10^3{\Omega}/sq$ respectively and transmittance over 80% at wavelength of 380nm~780nm. This study establishes DC magnetron sputtering process condition on ITO thin film by measuring electrical and optical properties of the thin film. As results, we obtained $300\;{\mu}{\Omega}cm$ resistivity of ITO films with good transmittance (above 90 %) under 90:10 wt% composition rate of $In_2O_3:SnO_2$. Also, we understood that the ITO thin film by DC magnetron sputtering depends on the deposition condition, especially substrate temperature, and the composition rate of $In_2O_3:SnO_2$ that is one of the most critical parameters was successfully optimized for high qualified transparent electrodes.

• Journal of the Korean institute of surface engineering
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• v.49 no.1
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• pp.54-61
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• 2016

Screen printing of commercially available Ag paste is the most widely used method for the front side metallization of Si solar cells. However, the metallization using Ag paste is expensive and needs high temperature annealing for reliable contact. Among many metallization schemes, Ni/Cu/Sn plating is one of the most promising methods due to low contact resistance and mass production, resulting in high efficiency and low production cost. Ni layer serves as a barrier which would prevent copper atoms from diffusion into the silicon substrate. However, Ni based schemes by electroless deposition usually have low thermal stability, and require high annealing process due to phosphorus content in the Ni based films. These problems can be resolved by adding W element in Ni-based film. In this study, Ni-W-P alloys were formed by electroless plating and properties of it such as sheet resistance, resistivity, specific contact resistivity, crystallinity, and morphology were investigated before and after annealing process by means of transmission line method (TLM), 4-point probe, X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM).

• Journal of the Korean institute of surface engineering
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• v.49 no.2
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• pp.202-210
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• 2016

This study was intended to investigate the effect of the amount of magnesium addition and heat treatment in the Al-Mg coating film in order to improve corrosion resistance of aluminum coating. Al-Mg alloy films were deposited on cold rolled steel by physical vapor deposition sputtering method. Heat treatment was fulfilled in an nitrogen atmosphere at the temperature of $400^{\circ}C$ for 10 min. The morphology was observed by SEM, component and phase of the deposited films were investigated by using GDLS and XRD, respectively. The corrosion behaviors of Al-Mg films were estimated by exposing salt spray test at 5 wt.% NaCl solution and measuring polarization curves in deaerated 3 wt.% NaCl solution. With the increase of magnesium content, the morphology of the deposited Al-Mg films changed from columnar to featureless structure and particle size was became fine. The x-ray diffraction data for deposited Al-Mg films showed only pure Al peaks. However, Al-Mg alloy peaks such as $Al_3Mg_2$ and $Al_{12}Mg_{17}$ were formed after heat treatment. All the sputtered Al-Mg films obviously showed good corrosion resistance compared with aluminum and zinc films. And corrosion resistance of Al-Mg film was increased after heat treatment.