• 한국세라믹학회지
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• 제52권5호
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• pp.315-319
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• 2015

Yttria-stabilized zirconia (YSZ)-based micro tubular SOFC single cells were fabricated by electrophoretic deposition (EPD) process. Stable slurries for the EPD process were prepared by adding phosphate ester (PE) as a dispersant in order to control the pH, conductivity, and zeta-potential. NiO-YSZ anode support, NiO-YSZ anode functional layer (AFL), and YSZ electrolyte were consecutively deposited on a graphite rod using the EPD process; materials were then co-sintered at $1400^{\circ}C$ for 4 h. The thickness of the deposited layer increased with increasing of the applied voltage and the deposition time. A YSZ-based micro tubular single cell fabricated by the EPD process exhibited a maximum power density of $0.3W/cm^2$ at $750^{\circ}C$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1992년도 춘계학술대회 논문집
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• pp.117-121
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• 1992

Zinc oxide thin films were obtained from zinc acetate-2-water and oxygen by photo-CVD method. (1) The formation of ZnO films sarts from 100[$^{\circ}C$] and the deposition rate increases with increasing substrate temperature. (2) The rate of deposition was also affected by flow rates of O$_2$(reaction gas) and N$_2$(Carrier gas). (3) The deposition rate decreases with increasing O$_2$mole rate. (4) The transmission of the films was independent of oxygen mole rate and it was largely affected substrate temperature. (5) The electric resistivity of th films was largely varied at oxygen mole rate 10[%] and above 20[%], a plateau was encountered. Also, it increases with increasing substrate temperature. As the results, at substrate temperature: 200[$^{\circ}C$]; O$_2$gas mole rate:10[%]; reation time:10[min] pressure: 10$\^$-2/[atm], deposition rate; transmittance; resistivity were 780[A$\^$0/; 94[%]; 7${\times}$10$\^$-2/[$\Omega$$.$cm] respectively.

• 한국진공학회지
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• 제17권1호
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• pp.73-79
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• 2008

투명 전도성 산화물 전극(transparent conductive oxide electrodes)에 적용하기 위하여 RF 마그네트론 스퍼터링 방법에 의해 유리 기판 위에 산화아연 박막을 증착하였다. 투명 전극으로써 응용되기 위한 최적의 조건으로 기판온도를 상온으로 유지하고 RF power 200 W, 타겟과 기판사이의 거리(Dts)가 30 mm일 때 증착된 산화아연 박막으로부터 가장 낮은 비 저항값($7.4{\times}10^{-3}{\Omega}cm$)을 얻어 낼 수 있었으며, 85% 이상의 높은 투과율을 만족하는 박막을 얻을 수 있었다. 실질적인 소자로써의 응용을 위해 photo lithography를 통한 pattern을 형성, 습식 식각을 통하여 그 특성을 알아보고자 하였다. 습식 식각에서 사용된 식각용액(etchant)으로는 다양한 산 용액(황산, 옥살산, 인산)을 사용하였으며, 산의 농도 변화에 따른 식각특성과 식각시간 및 식각 이미지(표면형상)의 변화를 알아보았다. 결과적으로 산화아연의 습식식각은 산의 종류와 무관하게 산 용액의 농도(즉, pH)에 크게 의존하며, pH가 증가함에 따라 식각율이 지수함수적으로 감소하고 아울러 다양한 식각 이미지가 나타남을 최초로 고찰할 수 있었다.

• 대한기계학회논문집B
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• 제37권6호
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• pp.577-582
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• 2013

AZO(Aluminium-doped Zinc Oxide)는 기존의 LCD, OLED, 광센서, 유기태양전지 등의 투명전극에 널리 사용되는 ITO(Indium Tin Oxide)를 대체하기 위한 물질로 주목받고 있다. 본 연구에서는 유기태양전지의 투명 전극으로 많이 사용되는 ITO 를 대체하기 위해 원자층 증착(ALD) 공정의 저온 선택적 증착 특성을 이용하여 유연성 폴리머인 PEN 기판상에 AZO 투명전극을 직접 패턴방식으로 제조하고, 그 투명전극의 구조적, 전기적, 광학적 특성을 평가하였다. 전기적, 광학적 특성 결과들로부터 원자층 증작공정의 저온 선택적 증착 특성을 통해 형성된 AZO 투명전극의 유기태양전지로의 적용 가능성을 확인할 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.246-246
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• 2012

Smart catalyst design though novel catalyst preparation methods can improve catalytic activity of transition metals on reducible oxide supports such as titania by enhancement of metal oxide interface effects. In this work, we investigated Pt nanoparticles/titania catalysts under CO oxidation reaction by using novel preparation methods in order to enhance its catalytic activity by optimizing metal oxide interface. Arc plasma deposition (APD) and metal impregnation techniques are employed to achieve Pt metal deposition on titania supports which are prepared by multi-target sputtering and Sol-gel techniques. In order to tailor metal-support interface for catalytic CO oxidation reaction, Pt nanoparticles and thin films are deposited in varying surface coverages on sputtered titania films using APD. To assess the role of oxide support at the interface, APD-Pt is deposited on sputtered and Sol-gel prepared titania films. Lastly, characteristics of APD-Pt process are compared with Pt impregnation technique. Our results show that activity of Pt nanoparticles is improved when supported over Sol-Gel prepared titania than sputtered titania film. It is suggested that this enhanced activity can be partly ascribed to a very rough titania surface with the higher free metal surface area and higher number of sites at the interface between the metal and the support. Also, APD-Pt shows superior catalytic activity under CO oxidation as compared to Pt impregnation on sputtered titania support. XPS results show that bulk oxide is formed on Pt when deposited through impregnation and has higher proportion of oxidized Pt in the form of $Pt^{2+/4+}$ oxidation states than Pt metal. APD-Pt shows, however, mild oxidation with large proportion of active Pt metal. APD-Pt also shows trend of increasing CO oxidation activity with number of shots. The activity continues to increase with surface coverage beyond 100%, thus suggesting a very rough and porous Pt films with higher active surface metal sites due to an increased surface area available for the reactant CO and $O_2$ molecules. The results suggest a novel approach for systematic investigation into metal oxide interface by rational catalysts design which can be extended to other metal-support systems in the future.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.329-329
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• 2007

Photoconductive poly crystalline lead oxide coated on amorphous thin film transistor (TFT) arrays is the best candidate for direct digital x-ray detector for medical imaging. Thicker films with lessening density often show lower x-ray induced charge generation and collection becomes less efficient. In this work, we present a new methodology used for the high density deposition of PbO. We investigate the structural properties of the films using X-ray diffraction and electron microscopy experiments. The film coatings of approximately $200\;{\mu}m$ thickness were deposited on $2"{\times}2"$ conductive-coated glass substrates for measurements of dark current and x-ray sensitivity. The lead oxide (PbO) films of $200\;{\mu}m$ thickness were deposited on glass substrates using a wet coating process in room temperature. The influence of post-deposition annealing on the characteristics of the lead oxide films was investigated in detail. X-ray diffraction and scanning electron microscopy, and atomic force microscopy have been employed to obtain information on the morphology and crystallization of the films. Also we measured dark current, x-ray sensitivity and linearity for investigation of the electrical characteristics of films. It was found that the annealing conditions strongly affect the electrical properties of the films. The x-ray induced output charges of films annealed in oxygen gas increases dramatically with increasing annealing temperatures up to $500^{\circ}C$ but then drops for higher temperature anneals. Consequently, the more we increase the annealing temperatures, the better density and film quality of the lead oxide. Analysis of this data suggests that incorporation and decomposition reactions of oxygen can be controlled to change the detection properties of the lead oxide film significantly. Post-deposition thermal annealing is also used for densely film. The PbO films that are grown by new methodology exhibit good morphology of high density structure and provide less than $10\;pA/mm^2$ dark currents as they show saturation in gain (at approximate fields of $4\;V/{\mu}m$). The ability to operate at low voltage gives adequate dark currents for most applications and allows voltage electronics designs.

• 전기화학회지
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• 제2권1호
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• pp.46-49
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• 1999

Electron-beam 증발장치를 이용하여 리튬 박막 2차 전지 양극용 lithium cobalt oxide 박막을 제조하였다. Stainless steel -기판 위에 입혀진 $LiCoO_2$ 박막은 열처리 과정을 거쳐 잘 발달된 hexagonal 구조의 (003)면을 나타냈으며, 3.9 V 부근에서 전위 평탄 영역이 나타났다. $LiCoO_2$, 박막은 증착속도가 증가함에 따라 Li/co 조성비가 양론비에 근접하였으며, $15{\AA}/s$의 증착속도로 제작한 경우 높은 방전용량을 나타내었다. 열처리 온도가 증가함에 따라 용량이 증가하여 $700^{\circ}C$에서 최대 값을 나타내었으나, 그 이상의 온도에서는 기판과의 반응 때문에 방전용량이 현저히 감소하였다. 박막 내부의 리튬과 코발트의 불균일한 조성은 초기 방전용량의 감소를 가져왔다.

• 마이크로전자및패키징학회지
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• 제23권3호
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• pp.31-35
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• 2016

본 논문은 원자층 증착법을 이용해 증착된 YSZ 박막을 산화 세륨계 전해질 기반 고체 산화물 연료전지의 연료극 중간층으로 적용한 결과를 보여준다. $500^{\circ}C$ 이상의 고온에서는 산화 세륨계 전해질의 전기전도도가 상승하여 이를 전해질로 사용한 고체 산화물 연료전지의 개회로 전압이 하강하고 성능이 저하된다. 원자층 증착법을 이용해 연료극 측 전해질 표면에 증착된 YSZ 박막은 얇은 두께(60 nm)에도 불구하고 산화 세륨계 전해질 표면을 완벽하게 도포함으로써, 전해질을 관통하는 전자의 흐름을 막아 개회로 전압을 최대 20%까지 상승시켰다. 이를 통해 $500^{\circ}C$에서의 최대 전력 밀도는 52%가 상승하였다.

• 한국재료학회지
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• 제18권10호
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• pp.521-528
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• 2008

We present the structural, optical, and electrical properties of amorphous silicon suboxide (a-$SiO_x$) films grown on indium tin oxide glass substrates with a radio frequency magnetron technique from a polycrystalline silicon oxide target using ambient Ar. For different substrate-target distances (d = 8 cm and 10 cm), the deposition temperature effects were systematically studied. For d = 8cm, oxygen content in a-$SiO_x$ decreased with dissociation of oxygen onto the silicon oxide matrix; temperature increased due to enlargement of kinetic energy. For d = 10 cm, however, the oxygen content had a minimum between $150^{\circ}\;and\;200^{\circ}$. Using simple optical measurements, we can predict a preferred orientation of liquid crystal molecules on a-$SiO_x$ thin film. At higher oxygen content (x > 1.6), liquid crystal molecules on an inorganic liquid crystal alignment layer of a-$SiO_x$ showed homogeneous alignment; however, in the lower case (x < 1.6), liquid crystals showed homeotropic alignment.

• E2M - 전기 전자와 첨단 소재
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• 제16권9호
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• pp.64.2-65
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• 2003

A 4 nm layer of ZrOx (targeted x-2) was deposited on an interfacial layer(IL) of native oxide (SiO, t∼1.2 nm) surface on 200 mm Si wafers by a manufacturable atomic layer chemical vapor deposition technique at 30$0^{\circ}C$. Some as-deposited layers were subjected to a post-deposition, rapid thermal annealing at $700^{\circ}C$ for 5 min in flowing oxygen at atmospheric pressure. The experimental x-ray diffraction, x-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, and high-resolution parallel electron energy loss spectroscopy results showed that a multiphase and heterogeneous structure evolved, which we call the Zr-O/IL/Si stack. The as-deposited Zr-O layer was amorphous $ZrO_2$-rich Zr silicate containing about 15% by volume of embedded $ZrO_2$ nanocrystals, which transformed to a glass nanoceramic (with over 90% by volume of predominantly tetragonal-$ZrO_2$(t-$ZrO_2$) and monoclinic-$ZrO_2$(m-$ZrO_2$) nanocrystals) upon annealing. The formation of disordered amorphous regions within some of the nanocrystals, as well as crystalline regions with defects, probably gave rise to lattice strains and deformations. The interfacial layer (IL) was partitioned into an upper Si $o_2$-rich Zr silicate and the lower $SiO_{x}$. The latter was sub-toichiometric and the average oxidation state increased from Si0.86$^{＋}$ in $SiO_{0.43}$ (as-deposited) to Si1.32$^{＋}$ in $SiO_{0.66}$ (annealed). This high oxygen deficiency in $SiO_{x}$ indicative of the low mobility of oxidizing specie in the Zr-O layer. The stacks were characterized for their dielectric properties in the Pt/{Zr-O/IL}/Si metal oxide-semiconductor capacitor(MOSCAP) configuration. The measured equivalent oxide thickness (EOT) was not consistent with the calculated EOT using a bilayer model of $ZrO_2$ and $SiO_2$, and the capacitance in accumulation (and therefore, EOT and kZr-O) was frequency dispersive, trends well documented in literature. This behavior is qualitatively explained in terms of the multi-layer nanostructure and nanochemistry that evolves.ves.ves.