• Current Photovoltaic Research
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• 제7권2호
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• pp.33-37
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• 2019

In this paper, we compared the performance of $Cu(In,Ga)(S,Se)_2$ (CIGSSe) thin film solar cell with CdS buffer layer deposited by irradiating 365 nm UV light with 8 W power in Chemcial Bath Deposition (CBD) process. The effects of UV light irradiation on the thin film deposition mechanism during CBD-CdS thin film deposition were investigated through chemical and electro-optical studies. If the UV light is irradiated during the solution process, the hydrolysis of Thiourea is promoted even during the same time, thereby inhibiting the formation of the intermediate products developed in the reaction pathway and decreasing the pH of the solution. As a result, it is suggested that the efficiency of the CdS/CIGSSe solar cell is increased because the ratio of the S element in the CdS thin film increases and the proportion of the O element decreases. This is a very simple and effective approach to control the S/O ratio of the CdS thin film by the CBD process without artificially controlling the process temperature, solution pH or concentration.

• 한국대기환경학회지
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• 제14권5호
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• pp.421-432
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• 1998

Deposition processes limit the life time of pollutants in the atmosphere and control the distance travelled before deposition. Thus the understanding about atmospheric deposition processes is essential for a proper assessment of the environmental impacts due to the anthropogenic pollutants. The dry deposition velocities are related to surface types, atmospheric stabilities, friction velocities, air pollutants and so on. In this study we simulated the dry deposition velocities of O3 in Pusan region. The calculated deposition velocities compared to the observed O3 data obtained during the summer of 1988 over a deciduous forest in Canada. The comparison showed that the model somewhat overpredicted deposition velocities for the average diurnal variations with maxima in daytime and minima in nighttime mostly due to the turbulence intensity.

• 한국정밀공학회지
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• 제27권6호
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• pp.98-104
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• 2010

Rapid Prototypes with internally colored objects are convenient by visualizing. A rapid prototyping method has been developed to fabricate mono-colored or multi-colored objects. In this work, a new process was proposed that can fabricate internally visible colored 3D objects in stereolithography parts. The process consists of projection stereolithography process using transparent photocurable resin for outer shapes and molten ink deposition process using molten solid ink for internal shapes. In molten ink deposition process, molten solid ink could be deposited uniformly in a designed pattern. To make molten solid ink uniform over a designed region, parametric study through a patterning solid ink was performed. By laminating resin and solid ink in sequence, the process can make colored 3D objects in StereoLithography(SL) parts. The practicality and effectiveness of the proposed process were verified through fabrication of colored basic 3D objects in SL parts.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.161-162
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• 2012

• Journal of Korean Vacuum Science & Technology
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• 제6권1호
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• pp.22-29
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• 2002

The process of energetic deposition has been simulated by using molecular dynamics (W) simulation and kinetic Monte Carlo (KMC) simulation. The atomistic mechanisms of film growth in energetic deposition are discussed.

• 한국표면공학회지
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• 제21권3호
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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.

• 한국재료학회지
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• 제33권11호
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• pp.491-496
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• 2023

As the demand for p-type semiconductors increases, much effort is being put into developing new p-type materials. This demand has led to the development of novel new p-type semiconductors that go beyond existing p-type semiconductors. Copper iodide (CuI) has recently received much attention due to its wide band gap, excellent optical and electrical properties, and low temperature synthesis. However, there are limits to its use as a semiconductor material for thin film transistor devices due to the uncontrolled generation of copper vacancies and excessive hole doping. In this work, p-type CuI semiconductors were fabricated using the chemical vapor deposition (CVD) process for thin-film transistor (TFT) applications. The vacuum process has advantages over conventional solution processes, including conformal coating, large area uniformity, easy thickness control and so on. CuI thin films were fabricated at various deposition temperatures from 150 to 250 ℃ The surface roughness root mean square (RMS) value, which is related to carrier transport, decreases with increasing deposition temperature. Hall effect measurements showed that all fabricated CuI films had p-type behavior and that the Hall mobility decreased with increasing deposition temperature. The CuI TFTs showed no clear on/off because of the high concentration of carriers. By adopting a Zn capping layer, carrier concentrations decreased, leading to clear on and off behavior. Finally, stability tests of the PBS and NBS showed a threshold voltage shift within ±1 V.

• 한국전기전자재료학회논문지
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• 제22권7호
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• pp.595-601
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• 2009

For the silicon oxide $(SiO_x)$ films prepared by using the facing target sputtering (FTS) apparatus that was manufactured to enhance the preciseness of the fabricated thin-film and sputtering yield rate by forming a higher-density plasma in the electrical discharge space for using it as a thin-film passivation system for flexible organic light emitting devices (FOLEDs). The deposition characteristics were investigated under various process conditions, such as array of the cathode magnets, oxygen concentration$(O_2/Ar+O_2)$ introduced during deposition, and variations of distance between two targets and working pressure. We report that the optimum conditions for our FTS apparatus for the deposition of the $SiO_x$ films are as follows: $d_{TS}\;and\;d_{TT}$ are 90mm and 120mm, respectively and the maximum deposition rate is obtained under a gas pressure of 2 mTorr with an oxygen concentration of 3.3%. Under this optimum conditions, it was found that the $SiO_x$ film was grown with a very high deposition rate of $250{\AA}$/min by rf-power of $4.4W/cm^2$, which was significantly enhanced as compared with a deposition rate (${\sim}55{\AA})$/min) of the conventional sputtering system. We also reported that the FTS system is a suitable method for the high speed and the low temperature deposition, the plasma free deposition, and the mass-production.

• Journal of Radiation Protection and Research
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• 제27권3호
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• pp.165-170
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• 2002

핵종의 지표 침적 모델의 고찰과 함께 방사성물질의 공기중 농도로부터 건침적 뿐 아니라 습침적에 따른 농작물 오염 영향을 분석, 고찰하였다. 이를 위해 방사성물질의 지표 침적량으로부터 농작물의 오염을 평가하는 기존 동적 섭식경로모델을 공기중 농도 또는 지표 침적량으로부터 평가할 수 있도록 개선하였다. 평가결과, 방사성물질의 지표 침적량은 습침적에 의한 영향이 건침적에 의한 영향보다 뚜렷이 높으나, 농작물의 오염정도는 핵종, 강우율 등에 따라 다르게 나타났다. 이러한 현상은 방사성물질의 지표 침적과 농작물에로의 차단중 어느 과정이 농작물 오염에 보다 지배적으로 작용하는가에 기인한다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.72.1-72.1
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• 2010

Thin film a-Si solar cells deposited by PECVD have many advantages compared to the traditional crystalline Si solar cells. They do not require expensive Si wafer, the process temperature is relatively low, possibility of scaling up for mass production, etc. In order to produce thin film solar cells, understanding the relationship between the material characteristics and deposition conditions is important. It has been reported by many groups that the band gap of the a-Si material and the deposition rate has an linear relationship, when RF power is used to control both. However, when the process pressure is changed in order to control the deposition rate and the band gap, a diversion from the well known linear relationship occurs. Here, we explain this diversion by the deposition condition crossing different plasma regions in the Paschen curve with a simple model. This model will become a guide to which condition a-Si thin films must be fabricated in order to get a high quality film.