광전극 폭 변화에 따른 W-상호연결 염료감응 태양전지 모듈의 전기적 특성 연구

오병윤,김상기,김두근,Oh, Byeong-Yun,Kim, Sang-Ki,Kim, Doo-Gun 한국전기전자재료학회 2013 전기전자재료학회논문지 Vol.26 No.4

In this study, the W-interconnected dye-sensitized solar cell (DSSC) modules composed of a number of rectangular cells connected in series were investigated, where neighboring cells are processed in reverse. The DSSC modules, a module of dimension about 200 mm ${\times}$ 200 mm, were fabricated with different working electrode width ranging from 5 mm to 21 mm. The short-circuit current of the module increased as the working electrode width increased. Whereas, the decrease in the working electrode width resulted in the increase of the conversion energy efficiency, fill factor, and open-circuit voltage, which is explained by the fact that the possibility that electrons are recombined along their path on the transparent conductive oxide substrate decreases. The module with the conversion energy efficiency of 3.59% was obtained with the working electrode width of 5 mm.

이온빔 조사된 용액 공정 기반 LaZnO 박막 위 액정 분자의 수평 배향 특성

오병윤,Oh, Byeong-Yun 한국전기전자재료학회 2019 전기전자재료학회논문지 Vol.32 No.5

The alignment characteristics of liquid crystal (LC) molecules on a solution-derived lanthanum zinc oxide (LZO) film under ion-beam irradiation were demonstrated. Using the solution process, an LZO film was fabricated on the glass substrate and cured at $100^{\circ}C$. Afterwards, ion-beam irradiation was performed following the LC alignment method. Using this film, an LC cell was fabricated and the characteristics of the LC alignment were verified. Cross polarizing microscopy and the crystal rotation method were used to investigate the alignment state of the LC molecules on the LZO films. Furthermore, field emission scanning electron microscopy and X-ray photoelectron spectroscopy were used to explore the effect of the ion-beam irradiation on the LZO film. Through these, it was confirmed that the ion-beam irradiation induced surface modification, which demonstrated anisotropic physical and chemical surface characteristics. Due to this, uniform LC alignment was achieved. Finally, the residual DC and anchoring energy of the LC cell based on the LZO films were measured using a capacitance-voltage curve.

무기막 NiOx의 정렬 패턴 전사를 이용한 액정의 배향 특성 연구

오병윤,Oh, Byeong-Yun 한국전기전자재료학회 2019 전기전자재료학회논문지 Vol.32 No.5

We demonstrate an alignment technology using an imprinting process on an inorganic NiOx film. The aligned nanopattern was fabricated on a silicon wafer by laser interference lithography. The aligned nano pattern was then imprinted onto the sol-gel driven NiOx film using an imprinting process at an annealing temperature of $150^{\circ}C$. After the imprinting process, parallel grooves had been formed on the NiOx film. Atomic force microscopy and water contact angle measurements were performed to confirm the parallel groove on the NiOx film. The grooves caused liquid crystal alignment through geometric restriction, similar to grooves formed by the rubbing process on polyimide. The liquid crystal cell exhibited a pretilt angle of $0.2^{\circ}$, which demonstrated homogeneous alignment.

티타늄 박막을 이용한 염료감응형 태양전지 모듈 특성에 관한 연구

오병윤(Byeong-Yun Oh),김필중(Phil-Jung Kim) 한국전기전자학회 2021 전기전자학회논문지 Vol.25 No.1

본 연구에서는 티타늄(Ti) 금속 박막을 사용해서 값비싼 산화주석(FTO) 전극을 대체된 염료감응형 태양전지(DSSC)의 제작 방법과 전기적 특성에 대해서 고찰하였다. Ti 박막의 증착 시간을 조절하여 박막의 두께를 변화시켰으며, Ti 박막의 두께가 두꺼워지면서 표면저항은 감소하였다. 대략 190nm 두께에서 FTO 박막의 표면저항과 비슷해짐을 알 수 있었으며, 250nm 두께에서 DSSC의 에너지 변환효율 4.24%로 가장 높았다. 더 나아가 DSSC 모듈을 제작해 평가함으로써 상용화의 가능성을 확인하였다. In this work, we consider the fabrication method and electrical characteristics of dye-sensitized solar cells (DSSCs), which use titanium (Ti) metal thin films to replace expensive fluorine tin oxide (FTO) electrodes. The thickness of the Ti thin film was changed by adjusting the deposition time of the Ti, and the surface resistance decreased as the thickness of the Ti thin film became thicker. The thickness of the Ti thin film was shown to be similar to the surface resistance of the FTO thin film at approximately 190nm and the DSSC with a thickness of approximately 250nm showed the highest energy conversion efficiency of 4.24%. Furthermore, the possibility of commercialization was confirmed by fabricating and evaluating the DSSC module.

Uniform Liquid Crystal Alignment Properties on Ion-Beam Irradiated Indium Zinc Oxide Films with Stable Electro-Optical Performances

Byeong-Yun Oh(오병윤) 대한전기학회 2019 전기학회논문지 P Vol.68 No.3

The uniform liquid crystal (LC) molecules alignment was successfully achieved by using ion-beam irradiated indium zinc oxide (IZO) films. Conducting the solution process as a film deposition method, the IZO film was deposited on the glass substrate and ion-beam with various energy was irradiated on the IZO film. To verify the LC alignment properties, anti-parallel cell was fabricated and polarizing optical microscope was used. Field emission scanning electron microscope was adopted to observe the surface morphology of the IZO Film. Furthermore, X-ray photoelectron spectroscopy was used to investigate the chemical composition change as ion-beam energy increased. The strong ion-beam irradiation induced the breakage of metal oxide bonds on the surface and this increased the surface anisotropic characteristics which greatly affected on the LC alignment. Finally, electro-optical performance of the twisted-nematic cell was measured.

유전체 방전 살균 극대화를 위한 금속 나노 구조를 이용한 표면 플라즈몬 전극에 관한 연구

기현철,오병윤,Ki, Hyun-Chul,Oh, Byeong-Yun 한국전기전자재료학회 2018 전기전자재료학회논문지 Vol.31 No.2

In this study, we investigated plasmon effects to maximize the sterilization of dielectric discharge. We predicted the effect using the finite difference time domain (FDTD) method as a function of electrode shape, size, and period. The structure of the electrode was designed with a thickness of 100 nm of silver nanoparticles on a glass substrate, and was varied according to the shape, size, and period of the electrode hole. Based on the results, it was confirmed that the effect of plasmons was independent of the shape of the electrode hole. It was thus confirmed that the plasmon effect depended only on the size and period of the holes. Further, the plasmon effect was affected by the size rather than period of the holes. Because the absorption of light by the metal varied according to the size of the hole, the plasmon effect generated by the absorption of light also varied. The best results were obtained when the radius and period of the electrode holes were $0.1{\mu}m$ and $0.4{\mu}m$, respectively.

LVDC 배전을 위한 출력 380V DC-DC 컨버터 설계에 관한 연구

김필중(Phil-Jung Kim),양성수(Seong-Soo Yang),오병윤(Byeong-Yun Oh) 한국전기전자학회 2020 전기전자학회논문지 Vol.24 No.1

본 연구에서는 LVDC 배전용 출력 380V DC-DC 컨버터를 3가지 유형으로 설계하였고, 시뮬레이션을 통해 3가지 유형의 DC-DC 컨버터의 전압과 전류 특성을 비교 분석하였다. 전력용 MOSFET와 2개의 전류억제용 IGBT를 병렬구조로 적용하여 컨버터를 구성한 경우, 출력 전압이 DC 380V로 안정화 된 시간이 9ms로 비교적 짧았으며, 출력 측 전류 변화 폭도 44.8~50.2A로 IGBT를 적용하지 않았을 경우(68~83A) 보다 훨씬 변화 폭도 작고 전류억제 효과도 더 뛰어남을 알 수 있었다. 이러한 결과는 제안한 LVDC 배전용 DC-DC 컨버터가 스마트 그리드 구축에 적용 가능성이 있음을 시사한다. In this study, the output 380V direct current DC-DC converter for low-voltage direct current(LVDC) distribution was designed in three types, and the voltage and current characteristics of the three types of DC-DC converter were compared and analyzed through simulation. When the converter was configured using a parallel structure with the power metal-oxide semiconductor field-effect transistor and two current suppression insulated-gate bipolar transistors(IGBTs), the time when the output voltage was stabilized at DC 380V was relatively short with 9ms and the range of output current changes was also between 44.8A and 50.2A, indicating that the width of change was much smaller and the effect of current suppression was greater compared to when IGBT was not applied(68~83A). These results suggest that the proposed DC-DC converter for LVDC distribution is likely to be applied to smart grid construction.

광 투과도 제어형 액정 셀 연구

양성수(Seong-Soo Yang),김필중(Phil-Jung Kim),오병윤(Byeong-Yun Oh) 한국전기전자학회 2019 전기전자학회논문지 Vol.23 No.4

본 연구에서는 블라인드와 같은 스마트 윈도우 응용을 위해 액정 셀을 제작하였고, 광 투과율이 조절되는 시스템을 개발하였다. 액정 셀의 문턱전압은 1.325V였고, 투과율이 10%일 때 전압은 2.370V를 보여 제작된 액정 셀은 저전압으로 구동됨을 나타내었다. 또한, 액정 셀은 30ms 미만의 응답속도와 80°C/10분간 열을 가한 후에도 안정하게 구동되었다. 구동 시스템은 액정 셀의 인가되는 전압을 0.15V에서 3.53V까지 약 0.5V 간격으로 설계하였고, 실제 인가되는 전압에 따라 액정의 광 투과율이 변화됨을 확인하였다. 이러한 결과는 액정 셀이 스마트 윈도우 응용이 가능성이 있음을 시사한다. In this study, a liquid crystal (LC) cell was manufactured for smart window applications, such as blinds, and a system for controlling the light transmission rate was developed. The threshold voltage of the LC cell was 1.325 V and when the transmission rate was 10%, the voltage showed 2.370 V, indicating that the LC cell manufactured is driven at low voltage. The LC cell also operated reliably after being heated for 10 min at 80°C. with a response time of less than 30ms. The operation system designed the applied voltage of the LC cell with a interval of about 0.5 V from 0.15 V to 3.53 V and confirmed that the light transmission rate of the LC varies depending on the actual applied voltage. These results suggest that LC cells are likely to be smart window applications.