• Transactions on Electrical and Electronic Materials
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• v.12 no.3
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• pp.110-114
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• 2011

Polymeric films of high chemical stability and mechanical strength covered with a thin metallic film have been extensively used in various fields as electric and electronic materials. In this study, we have chosen polypropylene (PP) as the polymer due to its outstanding chemical resistance and good creep resistance. We coated thin nickel film on PP films by the electroless plating process. The surfaces of PP films were pre-treated and modified to increase the adhesion strength of metal layer on PP films, prior to the plating process, by an environment-friendly process with atmospheric plasma generated using dielectric barrier discharges in air. The surface morphologies of the PP films were observed before and after the surface modification process using a scanning electron microscope (SEM). The static contact angles were measured with deionized water droplets. The cross-sectional images of the PP films coated with thin metal film were taken with SEM to see the combined state between metallic and PP films. The adhesion strength of the metallic thin films on the PP films was confirmed by the thermal shock test and the cross-cutting and peel test. In conclusion, we made a composite material of metallic and polymeric films of high adhesion strength.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.329-331
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• 1995

Laser ablation was used to fabricate superconducting $YBa_2Cu_3O_{7-x}$ (YBCO) thin films on metallic substrates with an YSZ buffer layer. An ArF excimer laser with an wavelength of 193 nm was used to deposit both YSZ buffer layer and superconducting thin film. The characterizations of thin films were performed and compared. With a 200 nm YSZ buffer layer, c-axis orientation and $T_c$=85 K were obtained for a 200 nm-thick YBCO film.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.86.2-86.2
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• 2015

Cu2ZnSn(S,Se)4 thin film solar cells have been fabricated using sputtered Cu/Sn/Zn metallic precursors on Mo coated sodalime glass substrate without using a toxic H2Se and H2S atmosphere. Cu/Sn/Zn metallic precursors with various thicknesses were prepared using DC magnetron sputtering process at room temperature. As-deposited metallic precursors were sulfo-selenized inside a graphite box containing S and Se pellets using rapid thermal processing furnace at various sulfur to selenium (S/Se) compositional ratio. Thin film solar cells were fabricated after sulfo-selenization process using a 65 nm CdS buffer, a 40 nm intrinsic ZnO, a 400 nm Al doped ZnO, and Al/Ni top metal contact. Effects of sulfur to selenium (S/Se) compositional ratio on the microstructure, crystallinity, electrical properties, and cell efficiencies have been studied using X-ray diffraction, Raman spectroscopy, field emission scanning electron microscope, I-V measurement system, solar simulator, quantum efficiency measurement system, and time resolved photoluminescence spectrometer. Our fabricated Cu2ZnSn(S,Se)4 thin film solar cell shows the best conversion efficiency of 9.24 % (Voc : 454.6 mV, Jsc : 32.14 mA/cm2, FF : 63.29 %, and active area : 0.433 cm2), which is the highest efficiency among Cu2ZnSn(S,Se)4 thin film solar cells prepared using sputter deposited metallic precursors and without using a toxic H2Se gas. Details about other experimental results will be discussed during the presentation.

• Journal of the Korean institute of surface engineering
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• v.55 no.2
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• pp.63-69
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• 2022

Preparing various types of thin films of oxide semiconductors is a promising approach to fabricate efficient photoanodes and photocathodes for hydrogen production via photoelectrochemical (PEC) water splitting. In this work, we investigate the feasibility of an efficient photocathode for PEC water reduction of a p-type oxide semiconductor cupric oxide (CuO) thin film prepared via a facile method combined with sputtering Cu metallic film on fluorine-doped thin oxide (FTO) coated glass substrate and subsequent thermal oxidation of the sputtered Cu metallic film in dry air. Characterization of the structural, optical, and PEC properties of the CuO thin film prepared at various Cu sputtering powers reveals that we can obtain an optimum CuO thin film as an efficient PEC photocathode at a Cu sputtering power of 60 W. The photocurrent density and the optimal photocurrent conversion efficiency for the optimum CuO thin film photocathode are found to be -0.3 mA/cm² and 0.09% at 0.35 V vs. RHE, respectively. These results provide a promising route to fabricating earth-abundant copper-oxide-based photoelectrode for sunlight-driven hydrogen generation using a facile method.

• Transactions on Electrical and Electronic Materials
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• v.12 no.6
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• pp.267-270
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• 2011

In the process of inkjet-printed zinc tin oxide thin-film transistor, the effect of metallic interlayer underneath of source and drain electrode was investigated. The reason for the improved electrical properties with thin molybdenum oxide ($MoO_3$) layer was due to the chemically intermixed state of metallic interlayer, aluminum source and drain, and oxide semiconductor together. The atomic configuration of three Mo $3d_3$ and $3d_5$ doublets, three different Al 2p core levels, two Sn $3d_5$, and four different types of oxygen O 1s in the interfaces among those layers was confirmed by X-ray photospectroscopy.

• Proceedings of the Korean Vacuum Society Conference
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• 2003.02a
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• pp.72-72
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• 2003

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.688-691
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• 1997

Good quality superconducting $YBa_2Cu_30_{7-{\delta}}$(YBCO) thin films were grown on Hastelloy (Ni-Cr-Mo alloys) with yttria-stabilized zirconia(YSZ) buffer layers by in situ pulsed laser deposition in a multi-target processing chamber. Generally, Hastelloy exhibits excellent resistance to corrosion, fatigue, thermal shock, impact, and erosion. However, it is difficult to make films on flexible metallic substrates due to interdiffusion problems between metallic substrates and superconducting overlayers. To overcome this difficulty, it is necessary to use YSZ buffer layer since it will not only limit the interdiffusion process but also minimize the surface microcrack formation due to smaller mismatch between the film and the substrate. In order to enhance the crystallinity of YBCO films on metallic substrates, YSZ buffer layers were grown at various temperatures different from the deposition temperature of YBCO films. On YSZ buffer layer grown at higher temperature than that for depositing YBCO film, the YBCO thin film was found to be textured with c-axis orientation by x-ray diffraction and had a zero-resistance critical temperature of about 85K.

• Korean Journal of Materials Research
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• v.30 no.9
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• pp.441-446
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• 2020

Synthesizing nanostructured thin films of oxide semiconductors is a promising approach to fabricate highly efficient photoelectrodes for hydrogen production via photoelectrochemical (PEC) water splitting. In this work, we investigate the feasibility as an efficient photoanode for PEC water oxidation of zinc oxide (ZnO) nanostructured thin films synthesized via a simple method combined with sputtering Zn metallic films on a fluorine-doped tin oxide (FTO) coated glass substrate and subsequent thermal oxidation of the sputtered Zn metallic films in dry air. Characterization of the structural, optical, and PEC properties of the ZnO nanostructured thin film synthesized at varying Zn sputtering powers reveals that we can obtain an optimum ZnO nanostructured thin film as PEC photoanode at a sputtering power of 40 W. The photocurrent density and optimal photocurrent conversion efficiency for the optimum ZnO nanostructured thin film photoanode are found to be 0.1 mA/㎠ and 0.51 %, respectively, at a potential of 0.72 V vs. RHE. Our results illustrate that the ZnO nanostructured thin film has promising potential as an efficient photoanode for PEC water splitting.

• Journal of the Semiconductor & Display Technology
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• v.2 no.4
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• pp.31-35
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• 2003

We present a formation technique of thin film heater for heat transfer components. Thin film structures of Cr-Si have been prepared on top of alumina substrates by magnetron sputtering. More samples of Mo thin films were prepared on silicon oxide and silicon nitride substrates by electron beam evaporation technology. The electrical properties of the thin film structures were measured up to the temperature of $500^{\circ}C$. The thickness of the thin films was ranged to about 1 um, and a post annealing up to $900^{\circ}C$ was carried out to achieve more reliable film structures. In measurements of temperature coefficient of resistance (TCR), chrome-rich films show the metallic properties; whereas silicon-rich films do the semiconductor properties. Optimal composition between Cr and Si was obtained as 1 : 2, and there is 20% change or less of surface resistance from room temperature to $500^{\circ}C$. Scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) were used for the material analysis of the thin films.

• Journal of the Korean Ceramic Society
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• v.45 no.3
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• pp.161-166
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• 2008

The multi-films of a metallic film and a transparent conducting oxide (TCO, indium-tin oxide, ITO) film were formed on the stainless steel 316 and 304 plates by a sputtering method and an E-beam method and then the external metallic region of the stainless steel bipolar plates was converted into the metal nitride films through an annealing process. The multi-film formed on the stainless steel bipolar plates showed the XRD patterns of the typical indium-tin oxide, the metallic phase and the metal substrate and the external nitride film. The XRD pattern of the thin film on the bipolar plates modified showed two metal nitride phases of CrN and $Cr_2N$ compound. Surface microstructural morphology of the multi-film deposited bipolar plates was observed by AFM and FE-SEM. The metal nitride film formed on the stainless steel bipolar plates represented a microstructural morphology of fine columnar grains with 10 nm diameter and 60nm length in FE-SEM images. The electrical resistivity of the stainless steel bipolar plates modified was evaluated.