• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.05a
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• pp.114-116
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• 1992

ITO/TiO$_2$/Se solar cell were fabricated by vacuum deposition method, the Se and TiO$_2$were deposited on the ITO/Glass. Prior to the electrical properties of film, the provide Te between the ITO and the Se film were deposited by substrate temperature 20[$^{\circ}C$] and evaporation time 15[min], next time TiO$_2$ were treated by rf-magnetron sputtering in substrate temperature 250[$^{\circ}C$]. Fabricated ITO/TiO$_2$/Se solar cell were as follows : Open Voltage V$\_$oc/=848[mV], Short Circuit Current I$\_$sc/=10.79[mA/$\textrm{cm}^2$]. Fill Factor FF=0.518, energy conversion efficiency η=4.74[%] under the illumination of AM 1.

• Applied Science and Convergence Technology
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• v.26 no.4
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• pp.91-94
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• 2017

AThe effect of localized surface plasmon on silicon substrates was studied using silver nanoparticles. The nanoparticles were formed by self-arrangement through the surface energy using rapid thermal annealing (RTA) technique after the thin nanolayer of silver was deposited by thermal evaporation. By the theoretical calculation based on Mie scattering and dielectric function of air, indium tin oxide (ITO), and silver, the strong peak of scattering cross section of silver nanoparticles was found at 358 nm for air, and 460 nm for ITO, respectively. Accordingly, the strong suppression of reflectance under the condition of induced light of $30^{\circ}$ occurred at the specific wavelength which is almost in accordance with peak of scattering cross section. When the external quantum efficiency was measured using silicon solar cells with silver nanoparticles, there was small enhancement peak near the 460 nm wavelength in which the light was resonated between silver nanoparticles and ITO.

• International Journal of Air-Conditioning and Refrigeration
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• v.16 no.2
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• pp.44-50
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• 2008

This study presents test results of a mobile air-conditioning system using a potential alternative refrigerant, R152a. A series of performance tests have been carried out and cycle characteristics such as cooling capacity, energy efficiency ratio, suction and discharge pressures, and temperatures are presented, compared to those for the baseline R134a system. Tests were conducted with evaporation temperature of $5^{\circ}C$, condensation temperature of $45^{\circ}C$, subcooling temperature of $5^{\circ}C$, superheating temperature of $5^{\circ}C$, and compressor speed of 500-1500 rpm. The performance of R152a system with readjustment of an expansion valve showed better than those of R134a. The effect of oil on the pressure drop in the evaporator was also addressed.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1689-1696
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• 2008

Heat pumps transfer heat by circulating a substance called a refrigerant through a cycle of evaporation and condensation. But Heat pumps system by only using heat-source is not efficient. Because the mean temperature of North Korean winter season is low, economy of air heat-source heat pump descend. This paper is practiced the simulation on evaluation criteria for Heat pump heating and cooling systems to Rolling Stock. Efficiency of the heat pump in order improving from certainly the development of the technique will be able to prevent a freezing actual condition must proceed. As a result, Below $-10^{\circ}C$ used heating and cooling systems of heat pump format even in cold winter season and is serviceable confirmed with heat source supply circle of the Rolling Stock.

• Polymer(Korea)
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• v.39 no.1
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• pp.6-12
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• 2015

In order to improve the poor water solubility of aceclofenac, it was loaded into solid Kollidon VA 64 dispersion prepared by spray drying and rotary evaporation methods using different drug and polymer ratios. Morphology and physicochemical behavior of the aceclofenac loaded solid dispersions was analyzed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), and differential scanning calorimetry (DSC). Encapsulation efficiency and dissolution behavior in a simulated intestinal juice of aceclofenac in the solid dispersions was measured using HPLC and the latter was compared with that of the active pharmaceutical ingredient (API) and Airtal$^{(R)}$. It was demonstrated that two methods could significantly improve the dissolution behavior of aceclofenac.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.12
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• pp.909-914
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• 2013

CIGS is one of thin film solar cell and has been studied so much, because of the possibility of low price and high efficiency. Until now, co-evaporation and sputtering were typical method to prepare CIGS absorption layer, and a few company commercialized solar cell by these method. However, non-vacuum process which has been studied for long time has not been progressed, though the merit of low price. Especially, aerosol deposition method has not been reported, because it is difficult to prepare a large quantity of various CIGS powder. In this study, CIGS powder was synthesized by mechanochemical method and CIGS absorption layer was deposited by aerosol deposition method. The thickness of the CIGS layer was controlled by the number of deposition and the surface roughness of it was affected by the amount of flow gas. And, also, I-V curve of it appeared metallic property in the case of 'as deposition'. After heat treatment in Se-rich atmosphere, the electrical property of it changed to a semiconductor. CdS and transparent conduction layer were formed by a typical method on it for solar cell. The efficiency of cell was appeared 0.19%. Though the efficiency was low because of the disharmony in the after-process, it was conformed that CIGS solar cell could be prepared by aerosol deposition.

• Particle and aerosol research
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• v.13 no.3
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• pp.119-125
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• 2017

A novel two stage cylindrical cyclone was developed for a 3 phase separator in shale oil production industry. The cyclone performance was compared with a cone type cyclone and multi cyclone at the same experimental condition using water and oil mists generated by a humidifier and atomizer at the flow rate 1 to $2m^3/min$. The removal efficiency of total suspended water droplets by the novel cyclone, calculated using inlet and outlet concentrations measured by an optical particle counter, was 99% which is higher than 90% of oil droplet removal efficiency at $2m^3/min$. It might be due to the evaporation of small water droplets during the tests. The water and oil droplet removal performance of the novel cyclone based on the quality factor which is a function of pressure drop and removal efficiency was the highest among three cyclones. The results indicate that the cyclone could be an economical device to remove water and oil mists from shale gas generation processes where a huge three phase separator is commonly used.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.250-253
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• 2007

An evaporated Ti/Pd/Ag contact system is most widely used to make high-efficiency silicon solar cells, however, the system is not cost effective due to expensive materials and vacuum techniques. Commercial solar cells with screen-printed contacts formed by using Ag paste suffer from a low fill factor and a high shading loss because of high contact resistance and low aspect ratio. Low-cost Ni and Cu metal contacts have been formed by using electroless plating and electroplating techniques to replace the Ti/Pd/Ag and screen-printed Ag contacts. Ni/Cu alloy is plated on a silicon substrate by electro-deposition of the alloy from an acetate electrolyte solution, and nickel-silicide formation at the interface between the silicon and the nickel enhances stability and reduces the contact resistance. It was, therefore, found that nickel-silicide was suitable for high-efficiency solar cell applications. The Ni contact was formed on the front grid pattern by electroless plating followed by anneal ing at $380{\sim}400^{\circ}C$ for $15{\sim}30$ min at $N_{2}$ gas to allow formation of a nickel-silicide in a tube furnace or a rapid thermal processing(RTP) chamber because nickel is transformed to NiSi at $380{\sim}400^{\circ}C$. The Ni plating solution is composed of a mixture of $NiCl_{2}$ as a main nickel source. Cu was electroplated on the Ni layer by using a light induced plating method. The Cu electroplating solution was made up of a commercially available acid sulfate bath and additives to reduce the stress of the copper layer. The Ni/Cu contact was found to be well suited for high-efficiency solar cells and was successfully formed by using electroless plating and electroplating, which are more cost effective than vacuum evaporation. In this paper, we investigated low-cost Ni/Cu contact formation by electroless and electroplating for crystalline silicon solar cells.

• Current Photovoltaic Research
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• v.3 no.2
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• pp.39-44
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• 2015

$Cu(In,Ga)_3Se_5$ (${\beta}-CIGS$) has a band gap of 1.35 eV which is an optimum value for high solar-energy conversion efficiency. However, ${\beta}-CIGS$ film was not well characterized yet due to lower efficiency compared to $Cu(In,Ga)Se_2$ (${\alpha}-CIGS$). In this work, ${\beta}-CIGS$ films were fabricated by a three-stage co-evaporation of elemental sources with various Se fluxes. As the Se flux increased, the crystallinity of ${\beta}-CIGS$ phase was improved from the analysis of Raman spectroscopy and a deep-level defect was reduced from the analysis of photoluminescence spectroscopy. A Se treatment of the ${\beta}-CIGS$ film at $200^{\circ}C$ increased Ga content and decreased Cu content at the surface of the film. With the Se treatment at $200^{\circ}C$, the cell efficiency was greatly improved for the CIGS films prepared with low Se flux due to the increase of short-circuit current and fill factor. It was found that the main reason of performance improvement was lower Cu content at the surface instead of higher Ga content.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.4
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• pp.344-349
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• 2005

The optical and electrical characteristics of plasma display panel(PDP) using the vacuum in-line sealing technology compared with the conventional sealing process in this research. This PDP consisted of MgO protecting layer by e-beam evaporation and battier rib, transparent dielectric layer, dielectric layer, and electrodes by screen printer and then sealed off on Ne-Xe(4 ％) 400 Torr and 430。C. The brightness and luminous efficiency were good as the base vacuum level was higher, and it was to check the advantage of high vacuum level sealing, one of the strong points of the vacuum in-line sealing process. However, the brightness and luminous efficiency was dropped sharply because of a crack on MgO protecting layer by the difference of the expansion and contraction stress on high temperature in the vacuum states between MgO and substrate. Fortunately, the crack was prevented by MgO was deposited on higher temperature than 300。C. Finally, the PDP, was fabricated by the vacuum in-line sealing process, resulted the lower brightness than processing only the thermal annealing treatment in the vacuum chamber, but the luminous efficiency was increased by the reducing power consumption with the decreasing luminous current. The vacuum in-line sealing technology was not to need the additional thermal annealing process and could reduce the fabrication process and bring the excellent optical and electrical properties without the crack of MgO protecting layer than the conventional sealing process.