• Journal of the Korean Vacuum Society
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• v.19 no.4
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• pp.275-280
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• 2010

The influence of $O_2$-plasma treatment on $H_2$ post-treated BZO (ZnO:B) thin film using MOCVD (Metal-Organic Chemical Vapor Deposition) are investigated. An $O_2$-plasma treatment of the $H_2$ post-treated BZO thin films resulted in XRD peak of (100), (101) and (110). Also, electrical properties resulted in an increase in sheet resistance and work function. The weighted optical transmittance and haze at 300~1,100 nm of BZO thin films with $O_2$-plasma treatment on the $H_2$ post-treatment show approximately 86% and 15%, respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.91.2-91.2
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• 2010

SOFC는 높은 반응온도($600{\sim}1000^{\circ}C$)에서 작동되어 발전효율이 높고 다양한 연료를 사용할 수 있는 것이 장점이다. 하지만 고온에서의 운전은 구성요소의 열변형과 온도구배에 의한 전극촉매의 열화 그리고 밀봉재의 수명에 영향을 주어 결국 스택의 내구성을 감소시킨다. 특히 스택의 온도구배가 심화되면 국부적인 Hot spot를 형성하여 셀에 심각한 손상을 주게 된다. 본 과제에서는 SOFC 스택의 온도구배를 완화시키기 위한 내부개질기의 개발 및 고온용 분리판 소재의 정밀성형기술을 확보하고자 한다. 열/유동해석을 통하여 반응가스의 농도, 유속, 구조변경 등 내부개질기 온도구배에 대한 주요인자를 확인하였고, 장기 운전평가를 통하여 개질 촉매의 고온 활성 및 내구성에 대한 성능평가를 진행 중이다. 분리판의 경우, 고온용 소재(페라이트계 스테인레스)에 대한 기초실험을 실시하여 성형품질의 주요 인자를 파악하였으며 Proto-type 금형 설계 및 개발을 통하여 성형 기초기술을 확보하였다. 그리고 스택 내부온도를 구현할 수 있는 시뮬레이터를 설계 중에 있으며 이를 이용하여 개발된 내부개질기 및 분리판을 스택 운전환경에서 평가할 예정이다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.330-330
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• 2012

일반적으로 투명전극 재료로서 이용되는 Indium Tin Oxide (ITO)는 높은 전기전도도에도 불구하고, 가시광선 영역에서 높은 광학적 투과도를 지니고 있다. 즉, 비저항이 $10^{-3}{\Omega}/cm$ 보다 작으면서, 380 nm에서 780 nm사이의 가시광선 영역에서 80%이상의 투과도를 가지는 우수한 transparent conducting oxide 물질로 인식되고 있다. 또한 이 물질은 가시광선 영역에서의 굴절률이 대략 2정도이기 때문에, 다른 반도체재료와 진공사이의 계면에서 발생하는 반사를 줄여, 태양광전지나 LED 등에 이용될 수 있는 무반사 코팅재로 이용될 수 있다. 이러한 이유로 현재 각 분야에서 ITO에 관한 연구가 활발히 진행되고 있다. 본 연구에서는 ITO에 대한 기초연구로서, 전자빔 증착법으로 박막을 증착시키는 동안 증착속도에 따른 박막의 물성변화를 조사하였다. 또한 수직으로 증착할 때와 Glancing Angle Deposition 방법을 이용하였을 때, 증착속도에 따른 박막의 물성변화를 비교 분석하고자 하였다. 여기서, 증착속도는 $1{\AA}/s$에서 $4{\AA}/s$ 범위로 변화를 주었고, 증착물질과 기판의 각도는 $0^{\circ}$, $15^{\circ}$, $45^{\circ}$, $75^{\circ}$로 하였다. 먼저 수직으로 증착할 때, 증착속도의 변화에 따른 반사도, 투과도 및 굴절률과 증착단면의 구조를 비교하고, 다음으로 기판에 각도를 주어 박막을 증착하였을 때의 증착속도에 따른 박막의 광학적 및 구조적 물성의 변화를 측정하였다.

• Journal of Power System Engineering
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• v.8 no.3
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• pp.44-51
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• 2004

Effect of corrosion characteristics in relation to loaded stress in the welded zone of A5083-H116 aluminum alloy, in the seawater was studied. The corrosion experiment was performed for 120 hours on the specimens in the natural seawater tank with four steps of the loaded stress. The corrosion crack, corrosion rate, electrode potential, current, and corrosion pattern, etc. were examined for the specimens with the elapse of the immersion time. The main result derived from this study is the crack growth length is increased with the increasing loaded stress. The electrode potential and the corrosion current are decreased rapidly in the early stage of the corrosion, and then decreased gradually and stabilized eventually with the elapse of the immersion time. The test condition of the longer crack growth tends to show the higher corrosion rate. Corrosion pattern of the welded zone indicates that the depth and width of the pitting become increasing with the increasing loaded stress.

• Journal of the Semiconductor & Display Technology
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• v.6 no.4
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• pp.11-15
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• 2007

As preparing electrode for the OLED with the sputtering process, in order to be lower damage of the bottom organic layer and increase the life-time of the OLED, we prepared Al electrode for that by using Facing Targets Sputtering (FTS) system. Al electrode directly deposited on the cell (LiF/EML/HTL/Bottom electrode). Deposition condition was the working gas (Ar, Kr and Ar+Kr) and working gas pressure (1 and 6 mTorr). The film thickness and I-V curve of Al/cell were evaluated by a $\acute{a}$-step profiler and a semiconductor parameter (HP4156A) measurement. The thin film surface image was observed by a Atomic Force Microscope (AFM). In result, in comparison with about 11 [V] of the turn-on voltage of Al/cell with using the pure Ar gas, when Al thin film was deposited using the Ar-Kr mixture gas, the surface morphology was improved in some region and the turn-on voltage of Al/cell could be decreased to about 7 [V].

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1287-1294
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• 2001

As size of waveform is very small, ECG(electrocardiogram) signal is difficult to analyze for noise which is occurred when it measures. In order to obtain ECG clearly, it must eliminate that power line interference, baseline wandering, noise of muscle constriction. In ECG, the worst problem which is recorded signal of ECG is the baseline wandering elimination, which is occurred by rhythm of respiration and muscle constriction of part from attaching to an electrode. Such the baseline is roughly irregular wandering and shaking up and down therefore the part of the baseline wandering elimination is very important because it is difficulty of ECG diagnosis. In this study, as implementation of real-time signal processing digital filter it is applicable to analyze patient's heart disease by way of design of the baseline wandering elimination system.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.4
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• pp.139-143
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• 2005

For application of carbon nano-tube (CNT) as a counter electrode materials of dye-sensitized solar cell (DSSC), the electrochemical behavior of CNT electrode was studied, employing cyclic-voltammetry (C-V) and impedance spectroscopy. Fabrication of CNT-paste and formation of CNT-counter electrode for characteristic measurement have been carried out using ball-milling and doctor blade process, respectively. Unit cell for measurements was assembled using Pt electrode, CNT electrode, and iodine-embedded electrolyte. Field emission-scanning electron microscopy (FE-SEM) was used for structural investigation of CNT powder and electrode. Sheet resistance of electrode was measured with 4-point probe method. Electrochemical properties of electrode, C-V and impedance spectrum, were studied, employing potentiogalvanostat (EG&G 273A) and lock in amplifier (EG&G 5210). As a results, the sheet resistance of CNT electrode is almost similar to that of F-doped SnO2 (FTO) coated glass substrate as approximately 10 ohm/sq. From C-V and impedance spectroscopy measurements, it was found that CNT electrode has high reaction rate and low interface reaction resistance between CNT surface and electrolyte. These results provides that CNT electrode were superior to that of conventional Pt electrode. Particularly, the reaction rate in the CNT electrode is about thrice high than Pt electrode. Therefore. CNT electrode is to be good candidate material for counter electrode in DSSC.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.112-115
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• 2004

Photovoltaic effects in $CuPc/C_{60}$ heterojunction structure have been studied depending on thickness of exciton blocking layer(BCP) and electrodes. Bare ITO and polymer coated electrode(PEDOT:PSS) were used as an anode, and Al, Ca/Al, Mg/Al, LiF/Al, and LiAl were used as a cathode. Photovoltaic parameters depending on BCP layer thickness from 0 to 60 nm and electrodes having different work function were measured using Keithley 236 source-measure unit and a 500W xenon lamp (ORIEL 66021). We have seen that the BCP layer thickness severely affects on the performance of photovoltaic cells.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.180-181
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• 2008

화학양론적 $BaTiO_3$의 소결은 고온의 에너지를 필요로 하며, 내부전극과 세라믹충의 동시소성과정에서 Ni이 세라믹층으로의 확산이 발생되어 PTC의 물성저하를 초래한다. 본 연구에서는 저온에서 액상을 형성하여 소결온도를 낮추는 것으로 알려진 산화물 및 비산화물계 소결첨가제가 적층 PTC 세라믹스의 미세구조 및 전기적 특성에 미치는 영향에 대하여 고찰하였다. 소결과정에서 분해되어 기체를 형성하는 BN, $Li_2CO_3$, LiF의 경우 기공율을 증가시켜 산소의 이동경로를 형성하였으며, 이는 입계의 재산화를 용이하게 하여 PTC 효과를 보였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.444-444
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• 2008

For the polymer tandem cell, simple and advantaged solution-based method to electron transport intermediate layer is presented which are composed $TiO_2$ nanoparticles. Device were based on a regioregular Poly(3-hexylthiophene)(P3HT) and [6,6]-phenyl $C_{61}$ butyric acid methyl ester($PC_{60}BM$) blend as a donor and acceptor bulk-heterojunction. For the middle electrode interlayer, the $TiO_2$ nanoparticles were well dispersed in ethanol solution and formed thin layer on the P3HT:PCBM charge separation layer by spin coating. The layer serves as the electron transport layer and divides the polymer tandem solar cell. The open-circuit voltage (Voc) for the polymer tandem solar cells was closed to the sum of those of individual cells.