• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.91-93
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• 2008

The organic field-effect transistors with step-edge structure were fabricated. Source and drain electrodes were obliquely deposited by vacuum evaporation. The step-edge of the gate electrode serve as a shadow mask, and the short channel is formed at the step-edge. The excellent device performances were obtained.

• Journal of the Korean institute of surface engineering
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• v.21 no.3
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• pp.114-129
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• 1988

The principles of the physical vapour deposition processes(PVC); evaporation, sputting, and ion plating are presented and compared with each other with respect to coating properties, deposition rate and process control. The significance of coating sources and vacuum equipment for hard materials coating is discussed.

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.10a
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• pp.120-120
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• 1997

• Korean Journal of Metals and Materials
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• v.47 no.12
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• pp.828-833
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• 2009

As a fundamental study in the development of a distillation process for ferromanganese alloy melts, the evaporation behavior of an electrolytic manganese melt under reduced pressure was investigated. The melt temperature, vacuum degree, surface area of the melt, and reaction time were considered as experimental variables. The amount of vaporized manganese increases linearly as the reaction time increases, and the evaporation of manganese was promoted by increasing the temperature and surface area of the melt. In the pressure range below the equilibrium vapor pressure of manganese, the amount of vaporized manganese per unit surface area of the melt increased sharply with a decrease of the pressure in the reaction chamber. An empirical equation for the evaporation rate of manganese was derived by regression analysis. The evaporation coefficient of manganese was determined to be approximately $3.84{\times}10^{-3}(g{\cdot}K^{1/2})/(Pa{\cdot}cm^2{\cdot}min)$ under the investigated conditions.

• Journal of the Korean Vacuum Society
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• v.17 no.5
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• pp.466-472
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• 2008

Purple Gold is the alloy consisting of 78wt%Au-22wt%Al, and is expressed as a chemical formula, $AuAl_2$. Lately it is being used for the material of accessories or the decorative ornaments, being one of the colored golds having the peculiar purple color, like White Gold and Pink Gold. Purple Gold has the weak point in shaping through casting process due to the bad malleability and castability, being the intermetalic compound of Au and Al. Therefore, it is possible to produce the final product only by the cutting and the grinding process or to use it as a decorative coat with the thin film evaporation. This study implemented two kinds of thin film experiments. One is the case that heat treatment was made after Au and Al deposition evaporated separately with a weight ratio 78:22 on the 200nm$SiO_2$/Si substrate. The other is the case that the surface deposition was made through the vacuum evaporation, keeping the glass substrate temperature remain room temperature, using the bulk $AuAl_2$ as a source. The final film property was measured, focusing on the Purple Gold's color and thickness through the bare eye inspection, the microstructure analysis, the surface resistance analysis, the color difference analysis, and XRD analysis. Purple Gold was not formed, as the excessive surface agglomeration occurred, in case of being produced and treated thermally with 12.5nmAu/40nmAl/200nm$SiO_2$/Si structure. Our results suggest that of Purple Gold films, showing the same purple color as the bulk's, were successfully deposited with the direct thermal evaporation from the $AuAl_2$ bulk source.

• Korean Chemical Engineering Research
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• v.57 no.3
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• pp.378-386
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• 2019

In the present paper we report the calculation results of operation energy consumption for dissolved ions concentration technologies using vacuum evaporation (VE) and hydrate formation. Calculations were conducted assuming the tenfold concentration of saline water (0.35 wt% NaCl solution) of 1 mol/s at room temperature and atmospheric pressure employing vacuum evaporation at $69^{\circ}C$ and 30 kPa and hydrate-based concentration using $CH_4$, $CO_2$ and $SF_6$ as guest molecules. Operation energy consumption of VE-based concentration resulted in 47 kJ/mol, whereas those of hydrate-based concentration were 43, 32, and 28 kJ/mol for $CH_4$, $CO_2$ and $SF_6$ hydrates, respectively. We observe that hydrate-based concentration can a competitive option for dissolved ions recovery from energy consumption standpoint. However, the selection of guest gas is very critical, since it accordingly determines the hydration number, the hydrate formation energy, gas compression energy, etc. The selection of guest gas, separation of concentrated brine and water phases, and the enhancement of hydrate formation rate are the key factors for the commercialization of hydrated-based technology for concentrating dissolved ions.

• Resources Recycling
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• v.22 no.1
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• pp.48-54
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• 2013

A laboratory study was carried out to recover KI crystals with high purity by using fractional crystallization method from a waste solution generated from the production of polarizing film for LCD industry. The waste solution contains 1.3% KI, and other impurities such as B, Na, and PVA etc. With purity higher than 99.5% KI crystals were produced through refining process such as vacuum evaporation, fractional crystallization, filtering, and 24hr aging. Also the concentrated impurities were eliminated about 70% by recrystallization.

• Journal of the Korean Vacuum Society
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• v.13 no.2
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• pp.59-64
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• 2004

A study on the semiconductor laser-based atomic absorption spectroscopy was performed for monitoring physical vapor deposition process. Gadolinium metal was vaporized with a high evaporation rate by electron beam heating. Real-time atomic absorption spectra were measured by using tunable semiconductor laser beam at 770-794 nm (center wavelength of 780 nm) and its second harmonic at 388-396 nm. Atomic densities of metal vapor can be calculated from the absorption spectra measured. We plot the atomic densities as a function of the electron beam power and compare with the evaporation rates measured by quartz crystal monitor. We demonstrate that the semiconductor laser-based spectroscopic system developed in this study can be applied to monitor the physical vapor deposition process for other metals such as titanium.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.479-479
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• 2013

산화물 반도체 물질을 이용한 Thin film transistor (TFT) 소자는 기존의 비정질 Si TFT와 저온 다결정 Si TFT 소자가 가지지 못하는 장점들이 보고되면서 차세대 디스플레이용 소자로 주목을 받고 있다. 그 중 TFT의 채널 물질로 a-IGZO가 많이 활용되고 있다. a-IGZO의 활용이 더 많아지고 있는 이유는 저온공정이 가능하고 3.2 eV의 큰 밴드갭으로 투명하며 높은 균일도, 캐리어 이동도를 모두 가지고 있기 때문이다. 본 연구에서는 산화물 물질인 IGZO를 채널 층으로 사용한 TFT소자에서 IGZO의 캐리어인 전자의 이동경로를 금속을 통하여 이동하게 함으로써 전기적 특성의 변화를 관찰하였다. TFT는 다수 캐리어가 게이트 전압에 의하여 박막 아래쪽에 채널을 형성하여 동작한다. 이 때 IGZO박막과 SiO2 사이의 Al을 증착하여 다수 캐리어인 전자의 이동도를 향상시켰다. 전극으로 사용되어지는 Al은 IGZO박막과 ohmic contant이기 때문에 전자의 이동이 어렵지 않기 때문이다. 소자 제작은 게이트로 도핑된 P형 기판을 사용하였고 게이트 절연체로 SiO2 200 nm를 증착하였다. 채널층로 IGZO를 증착하기 전에 게이트 절연체 위에 evaporation으로 Al을 20 nm를 증착하였다. 이때 mask는 $2.4{\times}10^{-4}cm^2$ 크기의 dot 형태를 사용하였다. Al을 증착 후 RF sputtering으로 IGZO를 30 nm 증착하였으며 $350^{\circ}C$에서 90 min 동안 열처리하였다. 소스와 드레인은 evaporation으로 Al을 100 nm 증착하였다. HB 4145B 측정기로 I-V 그래프를 통하여 전기적 특성의 변화를 관찰하였다.

• Advances in Energy Research
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• v.4 no.2
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• pp.147-161
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• 2016

To start with, finding a sustainable method to produce sweet water and electricity by using renewable energies is one of the most important issues at this time. So, experimental and theoretical analysis of the performance of a closed solar powered still, which is jointed to photovoltaic cells and vacuum pump and equipped by nano plate, as the principle stage of zero discharge desalination process is investigated in this project. Major goal of this work is to reuse the concentrated brine of the Mobin petrochemical complex in order to produce potable, sweet water from effluent saline wastewater and generating electricity in the same time by using solar energy instead of discharging them to the environment. It is observed the increase in brackish water temperature increases the average daily production of solar desalination still considerably. Therefore, the nano plate and vacuum pump are added to augment the evaporation rate. The insolation rate, evaporation rate, the average brackish temperature, ambient temperature, density are investigated during a year 2013. In addition to obtain the capacity of solar powered still, the highest and lowest amount of water and electricity generation are reported during a twelvemonth (2013). Results indicate the average daily production is increased 16%, which represents 7.78 kW.h energy saving comparing with traditional solar still.