• 한국진공학회:학술대회논문집
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• 한국진공학회 2001년도 창립10주년 제20회 학술발표회
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• pp.141-141
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• 2001

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제36회 동계학술대회 초록집
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• pp.119-119
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• 2009

• 한국진공학회:학술대회논문집
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• 한국진공학회 1995년도 제9회 학술발표회 논문개요집
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• pp.24-24
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• 1995

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.84.1-84.1
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• 2010

Since the discovery of the carbon nanotube(CNTs), they have attracted much attention because of unique properties that may impact many fields of science and technology. The considerable properties of CNTs include high surface area, outstanding thermal, electrical conductivity and mechanical stability. However, uniform deposition of Pt nanoparticles on carbon surface remains inaccessible territory because of the inert carbon surface. In this study, we prepared directly oriented CNTs on carbon paper as a catalyst support in cathode electrode. carbon surface was functionalized using aryl diazonium salt for increasing adhesion of Ni particles which is precursor for growing CNTs. For fabricate electrode, CNTs on carbon paper were grown by chemical vapor deposition using Ni catalyst and Pt nanoparticles were deposited on CNTs oriented carbon paper by polyol method. The performance was measured using Proton electrolyte Membrane Fuel Cell(PEMFC). The structure and morphology of the Pt nanoparticles on CNTs were characterized by Scanning electron Microscopy(SEM) and Transmission electron Microscopy (TEM). The average diameter of Pt nanoparticles was 3nm.

• E2M - 전기 전자와 첨단 소재
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• 제8권2호
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• pp.171-175
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• 1995

Optimum condition of remote plasma enhanced chemical vapor deposition using orthogonal array method was chosen. Characteristics of oxide films deposited by RPECVD with SiH$_{4}$ and N$_{2}$O gases were investigated. Etching rate of the optimized SiO$_{2}$ films in P-etchant was about 6[A/s] that was almost the same as that the high temperature thermal oxide. The films showed high dielectric breakdown field of more than 7[MV/cm] and a resistivity of 8*10$^{13}$ [.ohmcm] around at 7[MV/cm]. The interface trap density of SiO$_{2}$/Si interface around the midgap derived from the high frequency C-V curve was about 5*10$^{10}$ [/cm$^{2}$eV]. It was observed that the dielectric constant of the optimized SiO$_{2}$ film was 4.29.

• 한국응용과학기술학회지
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• 제21권2호
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• pp.174-181
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• 2004

Multi-walled carbon nanotubes (CNTs) were prepared by thermal chemical vapor deposition (CVD) and microwave plasma chemical vapor deposition (MPCVD) using various combination of binary catalysts with four transition metals such as Fe, Co, Cu, and Ni. In the preparation of CNTs from acetylene precursor by thermal CVD, the CNTs with very high yield of 43.6 % was produced over $Fe-Co/Al_2O_3$. The highest yield of CNTs was obtained with the catalyst reduced for 3 hr and the yield was decreased with increasing reduction time to 5 hr, due to the formation of $FeAl_2O_4$ metal-aluminate. On the other hand, the CNTs prepared by acethylene plasma CVD had more straight, smaller diameter, and larger aspect ratio(L/D) than those prepared by thermal CVD, although their yield had lower value of 27.7%. The degree of graphitization of CNTs measured by $I_d/I_g$ value and thermal degradation temperature were 1.04 and $602^{\circ}C$, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.264-264
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• 2010

Single-walled carbon nanotubes (SWCNTs) were grown on a Si wafer by using thermal chemical vapor deposition (t-CVD). We investigated the effect of the catalyst deposition rate on the types of CNTs grown on the substrate. In general, smaller islands of catalyst occur by agglomeration of a catalyst layer upon annealing as the catalyst layer becomes thinner, which results in the growth of CNTs with smaller diameters. For the same thickness of catalyst, a slower deposition rate will cause a more uniformly thin catalyst layer, which will be agglomerated during annealing, producing smaller catalyst islands. Thus, we can expect that the smaller-diameter CNTs will grow on the catalyst deposited with a lower rate even for the same thickness of catalyst. The 0.5-nm-thick Fe served as a catalyst, underneath which Al was coated as a catalyst support as well as a diffusion barrier on the Si substrate. The catalyst layers were. coated by using thermal evaporation. The deposition rates of the Al and Fe layers varied to be 90, 180 sec/nm and 70, 140 sec/nm, respectively. We prepared the four different combinations of the deposition rates of the AI and Fe layers. CNTs were synthesized for 10 min by flowing 60 sccm of Ar and 60 sccm of $H_2$ as a carrier gas and 20 sccm of $C_2H_2$ as a feedstock at 95 torr and $810^{\circ}C$. The substrates were subject to annealing for 20 sec for every case to form small catalyst islands prior to CNT growth. As-grown CNTs were characterized by using field emission scanning electron microscopy, high resolution transmission electron microscopy, Raman spectroscopy, UV-Vis NIR spectroscopy, and atomic force microscopy. The fast deposition of both the Al and Fe layers gave rise to the growth of thin multiwalled CNTs with the height of ${\sim}680\;{\mu}m$ for 10 min while the slow deposition caused the growth of ${\sim}800\;{\mu}m$ high SWCNTs. Several radial breathing mode (RBM) peaks in the Raman spectra were observed at the Raman shifts of $113.3{\sim}281.3\;cm^{-1}$, implying the presence of SWCNTs (or double-walled CNTs) with the tube diameters 2.07~0.83 nm. The Raman spectra of the as-grown SWCNTs showed very low G/D peak intensity ratios, indicating their low defect concentrations.

• 한국결정성장학회지
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• 제17권3호
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• pp.91-94
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• 2007

Vapor liquid solid 기구에 의한 열화학기상증착법을 이용하여 Si (001) 기판 위에 $SnO_2$ 나노와이어를 성장시켰다. Au 박막 (3 nm)을 성장을 위한 촉매로 사용하여 Si(001) 기판 이에 순수 SnO powder (purity, 99.9%)를 반응 원료로 대기압 하 $950{\sim}100^{\circ}C$ 온도 범위, $750{\sim}800\;sccm$ 아르곤 분위기에서 $SnO_2$ 나노와이어를 성장시켰다. X-ray diffraction 분석을 통해 성장한 $SnO_2$ 나노와이어가 tetragonal rutile 구조임을 확인하였고, transmission electron microscopy 분석을 통해 단일 나노와이어의 결정 특성을 분석하였다. 또한, 상온 photoluminescence 분석을 통해 나노와이어 샘플로부터 600 nm 부근에서 나타나는 defect level 천이에 의한 넓은 emission band를 확인함으로써 성장한 나노와이어 $SnO_2$임을 확인하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.58.2-58.2
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• 2010

본 연구에서는 n-type wafer에 비정질 실리콘을 증착한 이종접합 태양전지를 열처리 방법을 이용하여 열처리의 효과를 분석함으로써 이종접합 태양전지에 효율적인 열처리 효과에 대하여 연구하였다. P, N-layer는 PECVD(Plasma-enhanced chemical vapor deposition) I-layer는 HWCVD(Hot wire chemical vapor deposition), ITO는 RF 마그네트론 스퍼터링법으로 동일한 조건에서 제작하였고 rapid thermal process를 이용하여 진공 중에서 $150^{\circ}C$, $200^{\circ}C$, $220^{\circ}C$, $250^{\circ}C$까지 열처리를 하였다. 열처리 전과 후 QSSPC로 minority carrier life time, 자외 가시선 분광분석 장치로 투과 반사도를, Ellipsometer로 흡수 계수 등의 변화를 조사하였다. 열처리 후 Minority carrier life time, Voc 및 광변환 효율이 증가하였다.

• 반도체디스플레이기술학회지
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• 제6권4호
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• pp.39-42
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• 2007

Temperature distribution of the circular heat source was studied by analyzing the heat transfer of the environment of the circular source for OLED. Circular nozzle source was used to fabricate thin organic layer as the organic material in it was heated, vaporized and deposited to the large size panel. A modified heater structure of circular source has been suggested. The results of numerical analysis shows that the modified heater structure can use 15% more powder in a batch than the original heater structure does. Moreover, the modified heater structure can improve the uniformity of organic vapor deposition by controlling the temperature.