• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.492-492
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• 2014

On account of the good conductivity and optical properties, TCO is generally used in silicon heterojunction solar cell since the emitter material, hydrogenated amorphous silicon (a-Si:H), of the solar cell has low conductivity compare to the emitter of crystalline silicon solar cell. However, the work function mismatch between TCO layer and emitter leads to band-offset and interfere the injection of photo-generated carriers. In this study, work function engineering of TCO by oxygen reactive sputtering method was carried out to identify the trend of band-offset change. The open circuit voltage and short circuit current are noticeably changed by work function that effected from variation of oxygen ratio.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.292-295
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• 2001

The NdBaCuO superconducting samples were prepared by the Zone melting under low oxygen partial pressure. After the zone-melting the oxygenation process of the NdBaCuO samples in a oxygen flow furnace was studied. In order to compare the oxygenation condition the sintering NdBaCuO samples were studied also. In the study it is found that the optimum temperature for the oxygenation is $350^{\circ}C$, and the oxygen flow speed, the sample volume and the surface area of the sample would influence the oxygenation and the oxygen content.

• Journal of Korean Society on Water Environment
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• v.24 no.4
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• pp.458-464
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• 2008

Bulking phenomena and scum formation are common problem in suspended growth system like the activated sludge plants for wastewater treatment. Apart from wastewater composition, operating conditions, such as mechanical stress by insufficient oxygen supply, are often decisive for the occurrence of a bulking or scumming problem. There were the comparative aeration tanks in terms of sludge bulking caused by the difference of mechanical aeration facilities in the wastewater treatment plant of N paper mill company. In this study the cause of bulking was investigated through not only the biological isolation and identification but also a series of operational data consideration. On the basis of the investigation results for bulking cause, the operational criteria on dissolved oxygen concentration was derived to decrease the bulking problem.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.759-760
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• 2006

Ti-6Al-4V has low specific gravity, high corrosion resistance and superior mechanical properties but it is very difficult to control oxygen content in MIM process. It is necessary to use powders with coarse particle size to decrease oxygen content of powders, so feedstocks with poor fluidity and sintered bodies with lower density are obtained in such cases. Fine titanium hydride-dehydride powders were blended with atomized powders to accomplish higher fluidity and sintered density. Sintered bodies had higher sintered density and mechanical properties equivalent to those of wrought materials by controlling oxygen content less than 0.35mass%.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.814-815
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• 2006

The removal of oxygen during sintering by carbothermic reduction was studied for steel compacts Fe-Cr-Mo-C and Fe-Mo-C prepared from prealloyed powders. The compacts were prepared by pressing at 600 and 1000 MPa and sintering at 1100 and $1300^{\circ}C$ in vacuum. It showed that for the Cr-Mo steel, deoxidation strongly depends on the sintering temperature, in contrast to the plain Mo steel; at $1300^{\circ}C$ very low oxygen levels were measured with the standard density compact while at high density still significant oxygen is contained. This indicates inhibition of final deoxidation by pore closure, but apparently without adverse effect on the mechanical properties.

• Journal of Surface Science and Engineering
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• v.31 no.2
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• pp.109-116
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• 1998

Highly transparent conductive pure and fluorine-doped tin oxide(FT0, $SnO_2$ : F) films have been prepared by low pressure metal organic chemical vapor deposition (LP-MOCVD) from various mixtures of tetramethyitin(TMT) with oxygen or oxygen containing ozone. The properties of TO films have been changed with the variation of gases, flow rate, and substrate temperature. The nsing of oxygen containing ozone instead of pure oxygen, reduced substrate temperature by 100-$150^{\circ}C$ while maintaining same thickness. The films prepared by using ozone showed the resistivity in the range from $10^~2$ to $10^{~3}\Omega$cm, and the mobiiity from 10 to $14\textrm{cm}^2$/Vs. Fluorine-doped tin oxide films had properties such as the resistivity about $10^{-4}\Omega$cm, and the mobility from 14 to $19\textrm{cm}^2$/Vs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.292-295
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• 2001

The NdBaCuO superconducting samples were prepared by the Zone melting under low oxygen partial pressure. After the zone-melting the oxygenation process of the NdBaCuO samples in a oxygen flow furnace was studied. In order to compare the oxygenation condition the sintering NdBaCuO samples were studied also. In the study it is found that the optimum temperature for the oxygenation is $350{\circ}C$, and the oxygen flow speed, the sample volume and the surface area of the sample would if1uence the oxygenation and the oxygen content.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.358-359
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• 2006

Ru-C nano-composite films were prepared by MOCVD, and their microstructures and their electrode properties for oxygen gas sensors were investigated. Deposited films contained Ru particles of 5-20 nm in diameter dispersed in amorphous C matrix. The AC conductivities associating to the interface charge transfer between Ru-C composite electrode and YSZ electrolyte were 100-1000 times higher than that of conventional paste-Pt electrodes. The emf values of the oxygen gas concentration cell constructed from the nano-composite electrodes and YSZ electrolyte showed the Nernstian theoretical values at low temperatures around 500 K. The response time of the concentration cell was 900 s at 500 K.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.122-123
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• 2006

Tin oxide nanoparticles (n-SnO and $n-SnO_2$) were synthesized by the inert gas condensation (IGC) method under dynamic gas flow of oxygen and argon at various conditions. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) method were used to analysis the size, shape and crystal structure of the produced powders. The synthesized particles were mostly amorphous and their size increased with increasing the partial pressure of oxygen in the processing chamber. The particles also became broader in size when higher oxygen pressures were applied. Low temperature annealing at $320^{\circ}C$ in air resulted to crystallization of the amorphous n-SnO particles to $SnO_2$.

• Journal of Surface Science and Engineering
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• v.32 no.3
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• pp.344-350
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• 1999

The surface chemical structure of three kinds of polyethylene (PE): high density (HD) PE, low density (LD) PE and linear (L)-LDPE exposed to Ar and $O_2$ plasmas has been investigated using XPS. Oxygen was incorporated in a more increased amount for HDPE than for L-LDPE and LDPE. Ar plasma tended to incorporate more oxygen than $O_2$ plasma. The XPS valence band spectra for Ar plasma exhibited a clear peak assigned to $O_2$s character. By chemical derivatization method it was found that the amount of -COOH group at the surface was much greater than that of -OH group. The hydrophilic nature of plasma-treated PE increased in the order: LDPE