• Proceedings of the Korean Vacuum Society Conference
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• 2004.02a
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• pp.170-170
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• 2004

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.337-337
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• 2012

Dye sensitized solar cell (DSSC) having high efficiency with low cost was first reported by Gr$\ddot{a}$tzel et al. Many DSSC research groups attempt to enhance energy conversion efficiency by modifying the dye, electrolyte, Pt-coated electrode, and $TiO_2$ films. However, there are still some problems against realization of high-sensitivity DSSC such as the recombination of injected electrons in conduction band and the limited adsorption of dye on $TiO_2$ surface. The surface of $TiO_2$ is very important for improving hydrophilic property and dye adsorption on its surface. In this paper, we report a very efficient method to improve the efficiency and stability of DSSC with nano-structured $TiO_2$. Atmospheric plasma system was utilized for nitrogen plasma treatment on nano-structured $TiO_2$ film. We confirmed that the efficiency of DSSC was significantly dependent on plasma power. Relative in the $TiO_2$ surface change and characteristics after plasma was investigated by various analysis methods. The structure of $TiO_2$ films was examined by X-ray diffraction (XRD). The morphology of $TiO_2$ films was observed using a field emission scanning electron microscope (FE-SEM). The surface elemental composition was determined using X-ray photoelectron spectroscopy (XPS). Each of plasma power differently affected conversion efficiency of DSSC with plasma-treated $TiO_2$ compared to untreated DSSC under AM 1.5 G spectral illumination of $100mWcm^{-2}$.

• Membrane Journal
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• v.13 no.2
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• pp.73-80
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• 2003

Abstract: The surfaces of poly (methylpentene)(PMP) were modified by Af and $NH_3$ plasma treatment, and their effects on permeation characteristics were investigated. The mole ratio of O/C in the surface was increased with Ar plasma treatment and consequently the surface became hydrophilic because of the possible formation of -OH, -COOH and C=O. The surface treated by $NH_3$ plasma also became hydrophilic due to the formation of amine and/or amide groups. The $CO_2$ permeability and its actual selectivity over N_2$ were 182 baller and 6.17 for the optimum condition of Ar-30W-6min, while 144 Baller and 6.13 for that of $NH_3$-30 W-8 min.

• Transactions on Electrical and Electronic Materials
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• v.7 no.4
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• pp.204-209
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• 2006

Photo Resist (PR) ashing process was carried out with the atmospheric pressure- dielectric barrier discharge (ADBD) using $SF_6/N_2/O_2$. Ashing rate (AR) was sensitive to the mixing ratio of the oxygen and nitrogen of the blower type of ADBD asher. The maximum AR of 5000 A/min was achieved at 2% of oxygen in the $N_2$ plasma. With increasing the oxygen concentration to more than 2% in the $N_2$ plasma, the discharge becomes weak due to the high electron affinity of oxygen, resulting in the decrease of AR. When adding 0.5% of SF6 to $O_2/N_2$ mixed plasma, the PR AR increased drastically to 9000 A/min and the ashed surface of PR was smoother compared to the processed surface without $SF_6$. Carbon Fluorinated polymer may passivate the PR surface. It was also observed that the glass surface was not damaged by the fluorine.

• Journal of the Korean Vacuum Society
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• v.17 no.3
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• pp.199-203
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• 2008

The effects of surface treatment by $O_2$ plasma on the Bio-FETs were investigated by using the pseudo-MOSFETs on the SOI substrates. After a surface treatment by $O_2$ plasma with different RF powers, the current-voltage and field effect mobility of pseudo-MOSFETs were measured by applying back gate bias. The subthreshold characteristics of pseudo-MOSFETs were significantly degraded with increase of RF power. Additionally, a forming gas anneal process in 2 % diluted $H_2/N_2$ ambient was developed to recover the plasma process induced surface damages. A considerable improvement of the subthreshold characteristics was achieved by the forming gas anneal. Therefore, it is concluded that the pseudo-MOSFETs are a powerful tool for monitoring the surface treatment of Bio-FETs and the forming gas anneal process is effective for improving the electrical characteristics of Bio-FETs.

• Proceedings of the KIEE Conference
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• 2006.10a
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• pp.71-72
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• 2006

플라스틱 기판 위에 유도 결합 플라즈마 화학적 기상 증착장치 (Inductively Coupled Plasma Chemicai Vapor Deposition, ICP-CVD) 를 사용하여 실리콘 산화막 ($SiO_2$)을 증착하고, 엑시머레이저 어널링 (Excimer Laser Annealing, ELA) 과 $N_{2}O$ 플라즈마 전처리를 통해, 전기용량-전압(Capacitance-Voltage, C-V) 특성과 항복 전압장 (Breakdown Voltage Field) 과 같은 전기적 특성을 개선시켰다. 에너지 밀도 $250\;mJ/cm^2$ 의 엑시머 레이저 어닐링은 실리콘 산화막의 평탄 전압 (Flat Band Voltage) 을 0V에 가까이 이동시키고, 유효 산화 전하밀도 (Effective Oxide Charge Density)를 크게 감소시킨다. $N_{2}O$ 플라즈마 전처리를 통해 항복 전압장은 6MV/cm 에서 9 MV/cm 으로 향상된다. 엑시머 레이저 어닐링과 $N_{2}O$ 플라즈마 전처리를 통해 평탄 전압은 -9V 에서 -1.8V 로 향상되고, 유효 전하 밀도 (Effective Charge Density) 는 $400^{\circ}C$에서 TEOS 실리콘 산화막을 증착하는 경우의 유효 전하 밀도 수준까지 감소한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.174-174
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• 2010

In this article, the dry etching mechanism of ZnO thin films in $N_2/Cl_2$/Ar gas chemistry was investigated. The ZnO thin films were deposited on Si substrate using Atomic layer deposition. The etching experiments were performed by inductively coupled plasma system. The maximum etch rate was104.5 nm/min and the highest selectivity of ZnO over $SiO_2$ was 3.3. Etching rate was measured by surface profiler. And the chemical reaction on the surface of the etched ZnO thin films was investigated by x-ray photo electrons pectroscopy. As a result of XPS, $Zn2p_{3/2}$ peak shifted toward a higher binding energy and the O-O and N-O bond were obtained from the sample of ZnO thin film which after plasma treatment.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.3
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• pp.1-8
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• 2019

In this study, Arc plasma was employed for the thermal decomposition of nitrous oxide($N_2O$). Conventional ignition systems such as torch, spark, and catalyst systems, have disadvantages in that they are not reliable and do not provide rapid responses. Therefore, this study suggests the plasma application of plasma to overcome the problems of conventional ignition methods. A gas temperature and combustion experiment was carried out to investigate the feasibility to a novel igniter. The gas temperature was measured around $960^{\circ}C$ at 1 g/s, 0.7 A at the nearest wall. In addition, a combustion test was successfully conducted in 3.1 sec after the plasma discharge was initiated with a main flow rate of 10 g/s. The energy consumption for ignition was 1,780 J(574 W).

• Korean Membrane Journal
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• v.1 no.1
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• pp.65-72
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• 1999

The surface of polypropylene membrane was modified by plasma treatment using Ar,$N_{2}$, $NH_{2}$ and $O_{2}$ Permeabilities for $CO_{2}$, $N_{2}$ and separation factor for $CO_{2}$ relative to $N_{2}$ were measured. The permeation experiments were performed by a variable volume method at $25^{\circ}C$ and 0.303MPa. The effects of the plasma conditions such as treatement time power input gas flow rate and pressure in the reactor on the transport properties of modified membrane were investigated. The surface of the plasma treated membrane was analyzed by means of FTIR-ATR XPS and AFM. The surface structure of the plasma treated membrane was fairly different from that of the untreated membrane. Although the permeation rates for both $CO_{2}$ and $N_{2}$ decreased with increasing plasma treatement time the separation factor was found to be improved by the plasma treatement. The operating conditions of plasma treatement imposed on membranes had notable effect on the permeability and separation factor.

• Current Photovoltaic Research
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• v.3 no.4
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• pp.112-115
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• 2015

In this study, the surface of ITO films was modified using $N_2-O_2$ molecular plasma, and the effects of oxygen concentration in the plasma on the ITO surface properties were investigated. Upon plasma treatment of ITO films, the surface roughness of ITO films seldom changed up to the oxygen concentration in the range of 0% to 40%, while the roughness of the films slightly changed at or above the oxygen concentration of 60%. The contact angle of water droplet on ITO films dramatically changed with varying oxygen concentration in the plasma, and the minimum value was found to be at the oxygen concentration of 20%. The plasma resistance at this condition exhibited a maximum value, and the change of resistance showed an inverse relationship compared to that of contact angle. From these results, it was conjectured that the chemical reactions in the sheath of the molecular plasma dominated more than the physical actions due to energetic ion bombardment, and also the plasma resistance could be used as an indirect indicator to qualitatively diagnosis the state of plasma during the plasma treatment.