• 한국수소및신에너지학회논문집
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• 제29권5호
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• pp.434-441
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• 2018

The pore size of nickel (Ni) bottom electrode layer (BEL) for low-temperature solid oxide fuel cells embedded with ultrathin-film electrolyte was controlled by changing the substrate surface morphology and deposition process parameters. For ~150-nm-thick Ni BEL, the upper side of an anodic aluminum oxide (AAO) substrate with ~65-nm-sized pores provided ~1.7 times smaller pore size than the lower side of the AAO substrate. For ~100-nm-thick Ni BEL, the AAO substrate with ~45-nm-sized pores provided ~2.6 times smaller pore size than the AAO substrate with ~95-nm-sized pores, and the deposition pressure of ~4 mTorr provided ~1.3 times smaller pore size than that of ~48 mTorr. On the AAO substrate with ~65-nm-sized pores, the Ni BEL deposited for 400 seconds had ~2 times smaller pore size than the Ni BEL deposited for 100 seconds.

• 한국세라믹학회지
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• 제52권5호
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• pp.344-349
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• 2015

An interconnect is the key component of solid oxide fuel cells that electrically connects unit cells and separates fuel from oxidant in the adjoining cells. To improve their surface stability in high-temperature oxidizing environments, metallic interconnects are usually coated with conductive oxides. In this study, lanthanum nickelates ($LaNiO_3$) with a perovskite structure are synthesized and applied as protective coatings on a metallic interconnect (Crofer 22 APU). The partial substitution of Co, Cu, and Fe for Ni improves electrical conductivity as well as thermal expansion match with the Crofer interconnect. The protective perovskite layers are fabricated on the interconnects by a slurry coating process combined with optimized heat-treatment. The perovskite-coated interconnects show area-specific resistances as low as $16.5-37.5m{\Omega}{\cdot}cm^2$ at $800^{\circ}C$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.328-328
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• 2007

$SnO_2$ has a high potential for electric and electronic applications. We have anodized pure tin metal and nano porous tin oxide film was obtained on pure Sn. Nano porous tin oxide were grown by anodization in nonaqueous-base electrolytes at different potentials between 5 V and 100 V. Pore size of ~100nm was observed by FE-SEM. Pore sizes as a function of applied voltage and anodizing time were characterized. We obtained nano porous tin oxide film having an uniform pore size at low temperature. High specific surface area of $SnO_2$ will be very useful for gas sensor, lithium battery, and dye sensitized solar cell.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.319.1-319.1
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• 2013

Solid oxide fuel cells (SOFCs) have been recognized as one of emerging renewable energy sources, due to minimized pollutant production and high efficiency in operation. The performance of SOFCs is largely dependent on the electrode polarization which involves the oxidation/reduction in cathodes and anodes along with the charge transport of ions and electronic carriers. Atomic layer deposition is based on the alternate chemical surface reaction occurring at low temperatures with high uniformity and superior step coverage. Such features can be extended into the coating of metal oxide and/or metal layer onto the porous materials. In particular, the atomic layer deposition is can manipulated in controlling the charge transport in terms of triple phase boundaries, in order to control artificially the electrochemical polarization in electrodes of SOFC. The current work applied atomic layer deposition of metal oxides intro the electrodes of SOFCs. The corresponding effect was monitored in terms of the electrochemical characterization. The roles of atomic layer deposition in solid oxide fuel cells are discussed towards optimized towards long-term durability at intermediate temperature.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.76.1-76.1
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• 2013

Atomic Layer Deposition (ALD) has remarkably developed in semiconductor and nano-structure applications since early 1990. Now, the advantages of ALD process are well-known as controlling atomic-level-thickness, manipulating atomic-level-composition control, and depositing impurity-free films uniformly. These unique properties may accelerate ALD related industries and applications in various functional thin film markets. On the other hand, one of big markets, Display industry, just starts to look at the potential to adopt ALD functional films in emerging display applications, such as transparent and flexible displays. Unlike conventional ALD process strategies (good quality films and stable precursors at high deposition processes), recently major display industries have suggested the following requirements: large area equipment, reasonable throughput, low temperature process, and cost-effective functional precursors. In this talk, it will be mentioned some demands of display industries for applying ALD processes and/or functional films, in terms of emerging display technologies. In fact, the AMOLED (active matrix organic light emitting diode) Television markets are just starting at early 2013. There are a few possibilities and needs to be developing for AMOLED, Flexible and transparent Display markets. Moreover, some basic results will be shown to specify ALD display applications, including transparent conduction oxide, oxide semiconductor, passivation and barrier films.

• 반도체디스플레이기술학회지
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• 제17권2호
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• pp.57-60
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• 2018

Recently, Thin-film transistors (TFTs) are fundamental building blocks for state-of-the-art microelectronics, such as flat-panel displays and system-on-glass. Zinc oxide thin films have the advantage that they can grow at low temperature and can obtain high charge movility. Also the zinc oxide thin film can be used to control the resistance according to the oxygen content, so it is very easy to obtain the desired physical properties. In this paper, we fabricated a zinc oxide thin film on a polished copper substrate through a solution process, then improved the crystallinity through a geat treatment porcess, and studied to transfer it on a flexible substrate after the heat treatment was completed.

• Korean Chemical Engineering Research
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• 제46권3호
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• pp.473-478
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• 2008

망간황화물이 NO의 선택적 촉매 환원에 미치는 영향을 반응성 및 속도론적평가와 TPR(Temperature Programmed Reduction), TGA분석을 통하여 고찰하였다. 망간산화물은 $200^{\circ}C$ 이하의 저온에서 우수한 질소산화물 전환을 보였으나, 망간황화물의 경우 황화정도에 따라 질소산화물 전환은 고온으로 전이하였다. 또한 질소산화물 전환율도 황화정도에 따라 감소하였다. TPR 실험결과 망간산화물들은 $160^{\circ}C$ 이하의 낮은 온도에서 환원이 시작되었으나 망간황화물은 $280^{\circ}C$ 이상의 온도에서 환원이 시작되었다. TPR 실험을 통한 환원 시작온도는 촉매의SCR 시작 온도와 관련이 있는 것으로 판단된다. 망간황화물의 활성화에너지는 다른 촉매에 비해 낮게 나타났으나 pre-exponential 상수 크기가 다른 촉매에 비해 1/1000배 만큼 작아 NO에 대한 활성이 낮게 나타났다. 천연망간광석은 함유된 다양한 금속산화물의 영향으로 순수한 망간산화물보다 낮은 온도에서 재생되었다.

• 소성∙가공
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• 제17권4호
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• pp.240-248
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• 2008

The effect of alloying elements(Mn, S, Mo, B) on the high temperature deformation behavior of Fe-29%Ni-17%Co (Kovar) alloy were investigated. And the effect of high temperature oxidation on the hot ductility was also studied. The hot ductility of Kovar alloy was drastically increased with the addition of Mn and lowering of S content. It has been found that the brittle intergranular fracture at high temperature cracking is closely associated with the FeS sulfide along the grain boundary. When Mn was added, the type of sulfide was changed to MnS from FeS and ductile intergranular fracture and transgranular fracture were promoted. The formation of oxide layer was found to have minimized the hot ductility of the Kovar alloy significantly. Grain boundary micro-cracks in the internal oxide region were noted following deformation due to high temperature, one of which acting as a notch that caused the poor hot workability of the oxidized specimen. The addition of Mo to the Kovar alloy could also retard the decrease in the hot ductility of the oxidized specimen through the prevention of notching due to internal oxidation. Hot ductility was remarkably improved by the addition of Boron. The improvement of hot ductility results from the grain boundary migration mainly due to the dynamic recrystallization at lower temperature range ($900{\sim}1000^{\circ}C$).

• ETRI Journal
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• 제44권3호
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• pp.491-503
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• 2022

Metal-oxide-semiconductor field-effect transistors (MOSFETs) are continuously scaling down in the nanoscale region to improve the functionality of integrated circuits. The scaling down of MOSFET devices causes short-channel effects in the nanoscale region. In nanoscale region, leakage current components are increasing, resulting in substantial power dissipation. Very large-scale integration designers are constantly exploring different effective methods of mitigating the power dissipation. In this study, a transistor-level input-controlled stacking (ICS) approach is proposed for minimizing significant power dissipation. A low-power ICS approach is extensively discussed to verify its importance in low-power applications. Circuit reliability is monitored for process and voltage and temperature variations. The ICS approach is designed and simulated using Cadence's tools and compared with existing low-power and high-speed techniques at a 22-nm technology node. The ICS approach decreases power dissipation by 84.95% at a cost of 5.89 times increase in propagation delay, and improves energy dissipation reliability by 82.54% compared with conventional circuit for a ring oscillator comprising 5-inverters.

• 공업화학
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• 제18권3호
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• pp.255-261
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• 2007

망간계 금속산화물을 이용한 저온 선택적 촉매 환원 반응에 대하여 연구하였다. 망간계 금속산화물은 $200^{\circ}C$ 이하의 저온에서 우수한 탈질 특성을 보인다. 온도에 따른 $NH_3/NOx$ 몰비 변화 실험을 통하여 미반응 암모니아의 배출은 몰비가 증가하고 온도가 감소할수록 증가하였으며, $NO_2$의 발생은 반대의 현상을 보였다. $NO_2$는 NO가 촉매 표면에 흡착된 후 nitrate종으로 산화되어 생성되는 것으로 보인다. 촉매 표면에 생성된 nitrate종과 흡착된 암모니아가 반응하기 때문에 $NH_3/NOx$ 몰비 1.0 이상에서도 미반응 암모니아의 배출이 없었다. 담지된 금속산화물의 영향은 Zr은 산화상태를 증가시켜 $NO_2$의 배출이 증가하였으며, Ce를 첨가시킨 경우 $NO_2$ 발생량이 감소하였다. 그러나 금속산화물의 첨가는 전체적으로 NOx 전환율을 감소시켰다