• 신재생에너지
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• 제17권1호
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• pp.1-6
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• 2021

Transparent conducting oxide (TCO) films have been widely used in optoelectronic devices, such as OLEDs, TFTs, and solar cells. However, thin films of indium tin oxide (ITO) have few disadvantages pertaining to process parameters such as substrate temperature and sputtering power. In this study, we investigated the requirements for using TCO films in silicon-based solar cells and the best alternative TCO materials to improve their efficiency. Moreover, we discussed the current status of high-efficiency solar cells using low-temperature TCO films such as indium zinc oxide and Zr-doped indium oxide.

• 대한화학회지
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• 제66권3호
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• pp.209-217
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• 2022

본 연구그룹에서는 투명 전도성 기판이 필요 없는 광감응형 전기변색 소자를 개발하였다. 이전의 연구에서 백금 촉매 적용에 의한 빠른 착색 및 탈색을 확인하였고, 저온소성형 WO₃졸과 TiO₂ 졸을 적용하여 플렉시블 필름형 소자를 구현하였으나, 이러한 소자가 4~5 시간 동안 태양광에 노출될 경우 과착색 되어 암막상태에서도 탈색이 되지 않는 현상을 확인하였다. 본 연구에서는 이러한 과착색 현상을 해결하기 위하여 광감응형 전기변색 소자의 전해질에(4-Hydroxy-2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPOL)을 첨가하였다. TEMPOL을 첨가제로 사용한 광감응형 전기변색 소자의 경우 4시간 이상 햇빛에 노출되어도 과착색이 되지 않고, 가역성이 크게 향상되는 것을 확인하였다. 다양한 농도의 TEMPOL을 적용하여 가시광 투과율 변화 및 착/탈색 속도를 비교하였고, 에너지 레벨 관점에서 가능한 TEMPOL의 과착색 방지 메커니즘을 제시하였다.

• 전기학회논문지
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• 제67권8호
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• pp.994-1001
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• 2018

In this paper, to studied about future power system construction using PSS / E-Python API. Python-based future system automatical construction methods and modeling of renewable sources. it confirmed the stability of the powert system for each renewable area by calculating the weighted short circuit ratio (WSCR) index. it calculated the short circuit ratio (SCR) and selected the transmission line linkage scenario to improve the stability of vulnerable areas. it confirmed the WSCR index improvement through the selected transmission line linkage of scenario, and analyzed the stability of the renewable power system applying the scenario. It describes Facts and Shunt devices adjustment for the load flow convergence. It describes the stable methed of the bus voltage through the transformer Ratio Tap adjustment. By performing PSS/E ASCC using the Python it was performed three-phase short circuit fault capacity analysis, it is confirmed whether excess of the fault current circuit breaker capacity. In order to contingency accident analysis, it have described the generation of one or two line list of each areas using the Python. The list is used to contingency analysis and describe the soluted of the transmission line overload through comparison before and after adding the scenario line.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.162.2-162.2
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• 2010

The energy storage system is considered to be one of the useful devices for energy storing and recycling. the energy storage system can save energy cost and stabilize the system voltage. This paper presents the development of two energy storage systems. One is 750V system for light rail system. the other is 1500V system for heavy rail system.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.373-376
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• 2009

CdTe thin films for photovoltaic cell devices were deposited on the glass substrates by solution-based deposition methods, at low temperature processing conditions. In order to characterize physical, optical, and electronic properties of CdTe light absorbing polycrystalline material, a series of analysis was carried out in this study.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.550-553
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• 2008

In this paper, experiments of air-breathing proton exchange membrane fuel cell (PEMFC) for mobile devices were carried out according to the cathode conditions. These conditions are defined by the cathode flow field plate type (the channel type, the open type) and the cathode surface direction. Single cell and 6-cell stack were used in this experiments. The experimental results showed that the open type cathode flow field plate gave better performance for small size PEMFCs because the open type cathode plate allowed better air convection than the channel type cathode plate. In the experiments related to the direction of the slits on the cathode flow field plate, the horizontal slit cell was better than the vertical slit cell. With respect to the cathode surface direction, when the cathode surface is placed in the direction normal to the ground, PEMFC generated more stable power in the mass transport loss region.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.538-541
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• 2007

An expansion device plays an important role in optimizing the heat pumps by controlling refrigerant flow and balancing the system pressures. Conventional expansion devices are being gradually replaced with electronic expansion valves due to increasing focus on comfort, energy conservation, and application of a variable speed compressor. In addition, the amount of refrigerant charge in a heat pump is another primary parameter influencing system performance. In this study, the flow characteristics of the expansion devices are analyzed, and the effects of refrigerant charge amount on the performance of the heat pump are investigated at various operating conditions. Cooling capacity of the heat pump system is strongly dependent on load conditions. The heat pump system is very sensitive with a variation of refrigerant charge amount. But, the performance of it can be optimized by adjusting the flow rate through expansion device to maintain a constant superheat at all test conditions.

• JSTS:Journal of Semiconductor Technology and Science
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• 제8권4호
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• pp.311-317
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• 2008

The measurement of dark ${\sigma}_D$, gamma-induced ${\sigma}_{\gamma}$ conductivities and the expected conductivity modulation ${\Delta}_{\sigma}$ in silicon wafers/samples is studied for developing a new technique for carrier lifetime evaluation. In this paper a simple method is introduced to find the carrier lifetime variations with the measured conductivity and conductivity modulation under dark and gamma irradiation conditions. It will be concluded that this simple method enables us to give an improved wafer evaluation, processing and quality control in the field of photovoltaic materials and other electronic devices.

• 한국전기전자재료학회논문지
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• 제28권9호
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• pp.555-560
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• 2015

This paper was proposed 900 V Power MOSFET with ESD protection circuits using zener diodes. And we were carried out and analyzed its electrical characteristics. As a result of designing 900 V power MOSFET, we obtained 1,000 V breakdown voltage, 3.49 V threshold voltage and $0.249{\Omega}{\cdot}cm^2$. And we designed ESD circuits using 2 series zener diode and 4 series zener diodes. After analyzing electrical characteristics, we obtained 26 V forward voltage drop and 47 V breakdown voltage. Therefore, This devices can enoughly use power module, SMPS and Automotive.

• 반도체디스플레이기술학회지
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• 제16권2호
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• pp.49-54
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• 2017

In this paper, recent researches on new and renewable energy have been conducted due to problems such as energy exhaustion and environmental pollution, and new researches on high efficiency and high speed switching are needed. Therefore, we compared the efficiency by using high speed switching devices instead of IGBT which can't be used in high speed switching. The experiment was performed theoretically by applying the same parameters of the high speed switching devices which are the Cool MOS of Infineon Co., SiC C3M of Cree, and GaN FET device of Transform, by implementing the DC-DC boost converter and measuring the actual efficiency for output power and frequency. As a result, the GaN FET showed good efficiency at all switching frequency and output power.