• Proceedings of the Korean Ceranic Society Conference
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• 2004.04b
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• pp.51.3-51.3
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• 2004

• Transactions on Electrical and Electronic Materials
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• v.10 no.5
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• pp.169-172
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• 2009

The ZnO/CuSn/ZnO (ZCSZ) multilayer films were deposited on polycarbonate substrates using reactive RF and DC magnetron sputtering. The thickness of each layer was 50 nm/5 nm/45 nm, respectively. The ZCSZ films showed a sheet resistance of $44{\Omega}$/Sq, which was an order of magnitude lower than that indium tin oxide (ITO) films. Although the ZCSZ films had a CuSn interlayer that absorbed visible light, both films had similar optical transmittances of 74% in the visible wavelength region. The figure of merit of the ZCSZ films was $1.0{\times}10^{-3}{\Omega}^{-1}$ and was greater than the value of the ITO films, $1.6{\times}10^{-4}{\Omega}^{-1}$. From the X-ray diffraction (XRD) analysis, the ITO films did not show any diffraction peaks, whereas the ZCSZ films showed diffraction peaks for the ZnO (100) and (002) phases. The hardness of the ITO and ZCSZ films were 5.8 and 7.1 GPa, respectively, which were determined using nano-indentation. From these results, the ZCSZ films exhibited greater optoelectrical performance and hardness compared to the conventional ITO films.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.107-107
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• 2011

오늘 날 transparent conductive oxide는 다양한 분야에서 활용되고 있다. 최근에는 태양전지 분야에서도 많이 활용되고 있으며, 초기에는 transmittance 및 낮은 sheet resistance 특성을 가지는 ITO가 많이 활용되었지만 thin film solar cell와 같이 hydrogenation 공정에 약한 ITO보다는 Al-doped ZnO가 사용되기 시작하면서 많은 연구가 진행되고 있다. 본 연구에서는 thin film solar cell 및 silicon heterojunction solar cell에 적용 가능한 Al-doped ZnO에 관한 연구로써 a-Si:H의 Si-H bonds에 영향을 주지 않는 낮은 영역의 substrate temperature와 power로 Al-doped ZnO를 형성하고 상기 parameter에 따른 Al-doped ZnO의 특성 변화에 대해서 분석하였다. 특히 substrate temperature가 변화할수록 carrier concentration 및 sheet resistance가 많은 변화를 보였으며 이로 인하여 transmittance 특성이 온도에 따라 좋아지다가 너무 높은 온도에서는 오히려 좋지 않게 되었다. 이는 너무 높은 carrier concentration은 free carrier absorption에 의해 transmittance 특성을 오히려 좋지 않게 한다. 우리는 본 연구를 통해 92.677% (450 nm), 90.309% (545 nm), 94.333% (800 nm)의 transmittance를 얻을 수 있었다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.197-197
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• 2009

전기도금방법으로 여러형태의 ZnO 나노구조를 ITO/glass 위에 전착하였다. 그 중 sheet 형태의 ZnO 나노구조 위에 $TiO_2$와 CdSe 나노입자를 전기화학적 방법으로 전착하여 유 무기 복합태양전지 및 염료감응형 태양전지의 anode로 적용하였다. 동일조건 하에서 ZnO-CdSe 형태의 전극을 사용하였을 때 Jsc, Voc 값이 상대적으로 다른 전극에 비해 증가하였다.

• Journal of the Korean institute of surface engineering
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• v.36 no.5
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• pp.393-397
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• 2003

The effects of the composition and additives on the blackening and deposition rate of electroless Ni-Zn plating have been examined. Hydrazine resulted in lower sheet resistance of the deposit than sodium hypophosphite. Zinc concentration more than 15 wt% and small amount of ammonium sulfate in the deposits were needed in obtaining Ni-Zn deposit with a black color. An optimum condition was obtained for the black Ni-Zn deposit at an appreciable deposition rate.

• Transactions on Electrical and Electronic Materials
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• v.15 no.4
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• pp.198-200
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• 2014

100 nm thick Ga doped ZnO (GZO) thin films were deposited with RF magnetron sputtering on polyethylene terephthalate (PET) and ZnO coated PET substrate and then the effect of the ZnO thickness on the optical and electrical properties of the GZO films was investigated. GZO single layer films had an optical transmittance of 83.7% in the visible wavelength region and a sheet resistance of $2.41{\Omega}/{\square}$, while the optical and electrical properties of the GZO/ZnO bi-layered films were influenced by the thickness of the ZnO buffer layer. GZO films with a 20 nm thick ZnO buffer layer showed a lower sheet resistance of $1.45{\Omega}/{\square}$ and an optical transmittance of 85.9%. As the thickness of ZnO buffer layer in GZO/ZnO bi-layered films increased, both the conductivity and optical transmittance in the visible wavelength region were increased. Based on the figure of merit (FOM), it can be concluded that the ZnO buffer layer effectively increases the optical and electrical performance of GZO films as a transparent and conducting electrode without intentional substrate heating or a post deposition annealing process.

• Journal of the Korean Society for Heat Treatment
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• v.25 no.6
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• pp.283-291
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• 2012

In order to increase the anti-oxidation property during the tailor welding blanked hot press forming process for a high strength boron steel sheet, we performed a different coating method on the boron-steel sheet such as 87% Al - 13% Si and Fe - 8.87 Zn dipping plating procedure. However, during laser welding process, the Al-Si coated steel sheet has showed a low tensile strength and about half value of elongation than the original boron-steel sheet. Aluminum and silicon, elements of coating layer were diffused into the boron-steel matrix and have shown a low strength result than non-coated specimen. On the other hand, Zinc-coated boron-steel has expectedly showed a excellent tensile strength and micro-harness value in the welded area like original boron-steel.

• Journal of the Korean Society for Heat Treatment
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• v.36 no.6
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• pp.359-366
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• 2023

Changes in microstructure and mechanical properties of Mg-1.0Al-1.0Zn-0.2Mn-0.5Ca (AZMX1100) alloy sheet manufactured by normal casting and twin roll casting process, were studied according to process and heat treatment. Non-uniform microstructure was observed in the initial sheet produced through both processes, and in particular, tilted dendrites and shifted central segregation were observed in the twin roll casting sheet. It was homogenized through hot rolling and heat treatment, and heat treated at 350℃ and 400℃ to compare the effect of heat treatment temperature. Both sheets were homogenized by the hot rolling process, and the grain size increased as the heat treatment temperature and time increased. It was confirmed that the grain size, deviation, and distribution of the second phase were finer and more homogenized in the TRC sheet. Accordingly, mechanical properties such as hardness, formability, and tensile strength also showed better values. However, unlike other previously reported AZMX alloy systems, it showed low formability (Erichsen value), which was judged by the influence of Al2Ca present in the microstructure.

• Journal of Powder Materials
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• v.15 no.4
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• pp.292-296
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• 2008

The electromagnetic (EM) wave absorption properties of the $Fe_{73}Si_{16}B_7Nb_3Cu_1$ nanocrystalline powder mixed with 5 to 20 vol% of Ni-Zn ferrites has been investigated in a frequency range from 100MHz to 10GHz. Amorphous ribbons prepared by a planar flow casting process were pulverized and milled after annealing at 425 for 1 hour. The powder was mixed with a ferrite powder at various volume ratios to tape-cast into a 1.0mm thick sheet. Results showed that the EM wave absorption sheet with Ni-Zn ferrite powder reduced complex permittivity due to low dielectric constant of ferrite compared with nanocrystalline powder, while that with 5 vol% of ferrite showed relatively higher imaginary part of permeability. The sheet mixed with 5 vol% ferrite powder showed the best electromagnetic wave absorption properties at high frequency ranges, which resulted from the increased imaginary part of permeability due to reduced eddy current.

• Journal of Welding and Joining
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• v.31 no.4
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• pp.7-12
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• 2013

The dissimilar welding between magnesium alloy and steel sheet was required in automobile industry to increase the strength of the dissimilar joints. Laser brazing is one of the good joining processes for Mgsteel dissimilar joint. In this study, the effect of coating materials was evaluated on the laser brazing for the dissimilar joint between AZ31 and coated steels such as Zn, Sn and Ni. Diode direct laser was used to braze the lap-edge joint with Mg600 filler wire and Superior #21 flux. The wettability was best on Zn coated steel. The interlayer was formed at the interface between brazement and steel for all coating materials. The strengths of brazed specimen were 146.5N/mm, 204.6N/mm and 101.6N/mm for Zn, Sn and Ni coated steel respectively.