• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.694-702
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• 2014

The micron-sized ITO(indium tin oxide) particles were prepared by spray pyrolysis from aqueous precursor solutions for indium, and tin and organic additives solution. Organic additives solution with citric acid(CA) and ethylene glycol(EG) were added to aqueous precursor solution for Indium and Tin. The obtained ITO particles prepared by spray pyrolysis from the aqueous solution without organic additives solution had spherical and filled morphologies whereas the obtained ITO particles with organic additives solution had more hollow and porous morphologies with increasing mole of organic additives. The micron-sized ITO particle with organic additives was changed fully to nano-sized ITO particle whereas the micron-sized ITO particle without organic additives was not changed fully to nano-sized ITO particle after post-treatment at $700^{\circ}C$ for 2 hours and wet-ball milling for 24 hours. The size of primary ITO particle by Debye-Scherrer formula and surface resistance of ITO pellet were measured.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1529_1530
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• 2009

The process conditions for fabricating p-type silicon pillars were optimized by controlling current density, bath temperature. To get best process flexibility for pillar arrays formation, three factors affecting pillar formation were changed. First, the solution bath was designed to keep constant temperature during the experiment irrespective of external temperature. Second, the counter Pt electrode was changed from rod type to mesh to obtain uniform distribution of current density. Third, Cr-Cu alloy electrode instead of Cu was used to increase electrode current density.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.593-593
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• 2013

나노패턴 제작은 차세대 초고밀도 반도체 메모리기술과 바이오칩 등 나노기술의 핵심 분야로, 나노패턴 구조를 나노-바이오 전자소자 및 반도체 산업분야에 적용할 경우 시장 선점 및 막대한 부가가치 창출 등을 통해 국가경쟁력 강화에 크게 기여할 것으로 기대된다. 하지만 대면적 패턴형성이 어려워 뿐만 아니라 $300^{\circ}$ 이상의 열처리 과정에 의한 생산성이 떨어진다. 또한 나노구조가 잘 이루어진 차원, 표면상태, 결정성, 화학적 조성을 갖도록 하는 합성 및 제조상의 어려움 때문이다. 이에 반해 자기정렬 ITO Dot 형성은 상기 기술한 1차원 나노구조형성을 하는 것에 비하여, 나노구조를 제작하기 위하여 공정이 단순하며, 비용 및 생산성 측면에서 유리 할 것으로 생각된다. 이에 본 연구는 E-beam을 이용하여 형성된 ITO 박막에 HCl solution을 이용하여 자기정렬 ITO Dot 형성 후 n-AlGaInP Vertical LED[VLED] 표면에 nano pillar의 두께에 각기 다르게 형성하였으며, 최종적으로 제작된 VLED의 전기적, 광학적 특성을 조사하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.801-804
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• 2002

Electrochemical capacitors are becoming attractive energy storage systems particularly for applications involving high power requirements such as hybrid systems consisting of batteries and electrochemical capacitors for electric vehicle propulsion. Both of amorphous cobalt oxide and manganese dioxide were prepared by sol-gel process reported in our previous work. Nanostructured supramolecular oligomer of 1,5-diaminoanthraquinone(DAAQ) coated metal oxides were successfully prepared by electrochemical oxidation from an acidic non-aqueous medium. We established process parameters of the technique for the formation of nano-structured materials. Furthermore, improved the capacitive properties of the nano structured metal oxide electrodes using controlled solution chemistry. $CoO_2$ and $MnO_2$-based composite electrode showed relatively good electrochemical behaviors in acidic electrolyte system with respect to specific capacity and scan rate dependency.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.248-248
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• 2006

The notable feature of the Cu(II) coordination polymer investigated here is its ability to self-assemble into a double-stranded helical structure with regular grooves along the helical axis, through the combination of metal-chloride dimeric interactions and repulsive interactions, as an organizing force. It is also remarkable that the double-stranded helices self-organize into a 2-D columnar structure in both the bulk state and aqueous solution. These results represent a unique example that weak metal-ligand bridging interactions can provide a useful strategy to construct stable double-stranded helical nanotubes.

• Journal of Electrochemical Science and Technology
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• v.7 no.1
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• pp.1-12
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• 2016

The production of oxygen and hydrogen from solar water splitting has been considered to be an ultimate solution for energy and environmental issues, and over the past few years, nano-sized semiconducting metal oxides alone and with graphene have been shown to have great promise for use in photocatalytic water splitting. It is challenging to find ideal materials for photoelectrochemical water splitting, and these have limited commercial applicability due to critical factors, including their physico-chemical properties, the rate of charge-carrier recombination and limited light absorption. This review article discusses these main features, and recent research progress and major factors affect the performance of the water splitting reaction. The mechanism behind these interactions in transition metal oxides and graphene based nano-structured semiconductors upon illumination has been discussed in detail, and such characteristics are relevant to the design of materials with a superior photocatalytic response towards UV and visible light.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.12
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• pp.2624-2630
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• 2002

Organic/inorganic hybrid materials have rapidly become a fascinating research field. In this study, $polyimide/TiO_2$ composites were synthesized from nano-sized anatase $TiO_2$ and two types of polyimide, that is, BPDA-PPD and PMDA-ODA. Nano-sized $TiO_2$ particles were prepared from $TiOEt_4$ solution by the sol-gel method. The synthesized PI/$TiO_2$ composites were characterized by using XRD, TGA, FT-IR, TEM, and Atomic Force Microscope(AFM). $TiO_2$ particles were dispersed well in polyimides and the mechanical and thermal stability of polyimide was improved with $TiO_2$ nano particles.

• Clean Technology
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• v.11 no.3
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• pp.153-164
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• 2005

This study found a reliable evaluation for four kinds of pb-Free plating solutions and it's layers, through pure Sn, SnAg, SnBi and SnCu. These four kind of solutions are widely used to pb-Free plating. Hull-cell, Harring-blum, coverage, throwing power, current efficiency, stability, life-time, composition, hardness, roughness, abrasion, scratch, solderability, corrosion, contact angle, morphology, SIR(Surface insulation resistance) and Whisker test were experimented. Also, Using ICP, XRF, FE-SEM, EDS, temperature/humidity chamber, solderability tester, hardness tester, roughness tester, abrasion tester, salt spray tester, contact angle tester, SIR tester, and microscope. In this paper could be shown the systematic and various analysis for reliability about four kinds of pb-Free plating solutions, processes and it's deposit surface.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.10
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• pp.122-127
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• 2012

A nano-electro-mechanical (NEM) memory simulator has been developed by using Matlab. The simulator can be used for the prediction of hysterisis curves, applied forces, steady- or transient-state behavior, program/erase energy consumption and potential energy. Predicting NEM memory behavior by simple user interface, the simulator will make the design of NEM memory cells simpler.

• Progress in Superconductivity
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• v.3 no.2
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• pp.188-192
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• 2002

To introduce flux pinning center in HTS-BSCCO system, nano-size MgO particles were uniformly distributed within the Bi-2223 grain by partial hydration of MgO. The existing method MgO doped Bi-2223 used nato-size MgO powders, which resulted in agglomeration during mixing or grain growth during heat-treatment due to the high surface energy of the fine particles. By hydration of the MgO surface, the agglomeration of the MgO powders was avoided and the size of remaining MgO core was controlled by changing hydration medium and time. The thin film obtained by spin coating of (Bi_$1.8/Pb_{0.4}$)$Sr_2$$_{Ca}$$2.2/Cu_3$ $O_{y}$ nitrate solution mixed with hydrated MgO showed the even distribution of nano-size MgO particles in the Bi-2212 grains.s.s.