• Korean Journal of Materials Research
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• v.8 no.4
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• pp.359-361
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• 1998

Visible photoluminescence(PU was observed from hydrogenated amorphous silicon deposited on silicon(a-Si : H/Si) using electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR- PECVD) with silane ($SiH_{4}$) gas as the reactant source. The PL spectra from a-Si : H/Si were very similar to those from porous silicon. Hydrogen contents of samples annealed under oxygen atmosphere for 2minutes at $500^{\circ}C$ by rapid thermal annealing were reduced to 1~2%, and the samples did not show visible PL, indicating that hydrogen has a very important role in the PL process of a- Si : H/Si. As the thickness of deposited a-Si : H film increased, PL intensity decreased. The visi¬ble PL from a-Si: H deposited on Si by ECR-PECVD with $SiH_{4}$ . is suggested to be from silicon hydrides formed at the interface between the Si substrate and the deposited a-Si : H film during the deposition.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.4
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• pp.65-70
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• 2011

Perfluorocompounds (PFCs) gases were decomposed by gliding arc plasma generated by AC pulse power. $N_2$ gas of 10 LPM flow rate and $H_2$ gas of 0.5 LPM were introduced into the gliding arc plasma generated between a pair of electrodes with SUS 303 material, and the PFCs gases were injected in the plasma and thereby were decomposed. The PFCs gas-decomposition-characteristics through the gliding arc plasma were analyzed by FT-IR, where pure $N_2$ and $H_2$-added $N_2$ environment were used to generate the gliding arc plasma. The PFCs gas-decomposition-properties were changed by electric power for gliding arc plasma generation and the H2 gas addition was effective to enhance the PFCs decomposition rate.

• Proceedings of the Materials Research Society of Korea Conference
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• 1994.11a
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• pp.85-85
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• 1994

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.11a
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• pp.39-44
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• 2003

• Korean Journal of Materials Research
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• v.6 no.7
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• pp.661-670
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• 1996

리모트 수소 플라즈마를 이용하여 실리콘 웨이퍼 표면 위에 있는 금속불순물의 제거 및 제거기구에 관하여 조사하였다. 실리콘의 표면과 내부분석을 위하여 TXRF(total reflection x-ray fluorescence)와 SPV(surface photovoltage), AFM(atomic force microscope)을 사용하였다. TXRF 분석결과 리모트 수소 플라즈마가 금속오염물질 제거에 상당한 효과가 있는 것으로 나타났다. TXRF분석결과 리모트 수소 플라즈마가 금속오염물질 제거에 상당한 효과가 있는 것으로 나타났다. 리모트 수소플라트마 처리 후 금속오염은 금속원소의 종류에 따라 1010atoms/$\textrm{cm}^2$-1011atoms/$\textrm{cm}^2$수준이었다. SPV분석결과를 보면 수소 플라즈마 처리에 의해 minority carrier 수명이 전반적으로 증가하였다. AFM 분석을 통하여 수소 플라즈마 처리가 표면 손상을 일으키지 않으며 표면의 거칠기에 나쁜 영향을 미치지 않음을 알 수 있었다. 또한 본 실험에서 나타난 결과들을 종합해 볼 때 금속오염물의 제거기구는 자연산화막 혹은 수소로 passivate된 실리콘 웨이퍼 표면을 수소 플라즈마에서 발생된 수소원자가 실리콘표면을 약하게 에칭할 때 떨어져 나가는 'lift-off'가 유력한 것으로 판단된다.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.5
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• pp.73-80
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• 1999

To decrease NOx and SOx using PPCP(Pulse-induced Plasma Chemical Process). This study is tried to obtain the relation and the basic data under the various conditions such the initial concentrations of NOx and SOx. The additional amount of hydrocarbon gases. The concentration of oxygen and input power etc. Especially, this study is focused on the effects of the additional hydrocarbon gases on the decrease of NOx and SOx.

• Journal of Industrial Technology
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• v.25 no.A
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• pp.141-149
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• 2005

We investigated numerically the evolutions of several chemical species which are important for film growth and particle generation in the pulsed $SiH_4$ plasmas. During the plasma-on, the $SiH_x$ concentration increases with time mainly by the generation reaction from $SiH_4$, but, during the plasma-off, decreases because of the hydrogen adsorption reaction. During the plasma-on, the concentrations of negative ions increase with time by the polymerization reactions of negative ions and those become almost zero in the sheath regions because of the electrostatic repulsion. During the plasma-off, the concentrations of negative ions decrease with time by the neutralization reactions with positive ions and some negative ions can diffuse toward the sheath regions because there is no electric field inside the reactor. The polymerized negative ions of higher mass can be reduced successfully by using the pulsed plasma process.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.11
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• pp.943-947
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• 2007

The effect of hydrogen and oxygen plasma treatments on the structural properties of carbon nanotube(CNT) has been systematically investigated. As the plasma power was increased, nano particles were appeared at the surface of CNTs. At high plasma power(300 Watt), the structure of CNT was changed from nanotube type to nano particles. However, in case of hydrogen plasma treatment, there was no change in microstructure of CNT. From the Raman analysis, the crystallinity of CNT was deteriorated by the plasma treatment, regardless of gas types.

• Plant Journal
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• v.4 no.4
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• pp.62-70
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• 2008

PGV(Plasma Gasification & Vitrification) system has been developed based on a pyrolysis melting gasification technology that provides the possibilities of acquiring renewable energy. As volume of wastes increases with the rapid industrialization and population growth, eco friendly disposal is drawing more social attention. Pyrolysis plasma technology is regarded as the best environmentally friendly process for the waste disposal among numerous waste disposal processes. Introduced in this paper is the behavior of the plasma torch and a computational fluid simulation dynamics is discussed for designing the melting furnace. Some PGV applications have also been discussed.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.5
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• pp.9-16
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• 2019

In today's global energy market, the importance of green energy is emerging. Hydrogen energy is the future clean energy source and one of the pollution-free energy sources. In particular, the fuel cell method using hydrogen enhances the flexibility of renewable energy and enables energy storage and conversion for a long time. Therefore, it is considered to be a solution that can solve environmental problems caused by the use of fossil resources and energy problems caused by exhaustion of resources simultaneously. The purpose of this study is to efficiently produce hydrogen using plasma, and to study the optimization of DME reforming by checking the reforming reaction and yield according to temperature. The research method uses a 2.45 GHz electromagnetic plasma torch to produce hydrogen by reforming DME(Di Methyl Ether), a clean fuel. Gasification analysis was performed under low temperature conditions ($T3=1100^{\circ}C$), low temperature peroxygen conditions ($T3=1100^{\circ}C$), and high temperature conditions ($T3=1376^{\circ}C$). The low temperature gasification analysis showed that methane is generated due to unstable reforming reaction near $1100^{\circ}C$. The low temperature peroxygen gasification analysis showed less hydrogen but more carbon dioxide than the low temperature gasification analysis. Gasification analysis at high temperature indicated that methane was generated from about $1150^{\circ}C$, but it was not generated above $1200^{\circ}C$. In conclusion, the higher the temperature during the reforming reaction, the higher the proportion of hydrogen, but the higher the proportion of CO. However, it was confirmed that the problem of heat loss and reforming occurred due to the structural problem of the gasifier. In future developments, there is a need to reduce incomplete combustion by improving gasifiers to obtain high yields of hydrogen and to reduce the generation of gases such as carbon monoxide and methane. The optimization plan to produce hydrogen by steam plasma reforming of DME proposed in this study is expected to make a meaningful contribution to producing eco-friendly and renewable energy in the future.