• 반도체디스플레이기술학회지
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• 제10권1호
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• pp.57-61
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• 2011

To develop high efficiency crystalline solar cells, the rear surface passivation is very important. In this paper, $Al_2O_3$ films deposited by thermal ALD(atomic layer deposition) method were studied for rear surface passivation of crystalline solar cells and their passivation properties were evaluated. After the deposition of $Al_2O_3$ films on p-type Si wafers, the lifetime was increased very much due to the reduction of interface state density and the field effects of the negative fixed charge in the films. Also, optimum annealing condition and effects of SiNx capping layer were investigated. The best lifetime was obtained when the films were annealed at $400^{\circ}C$ for 15min. And the lifetime degradation of the $Al_2O_3$ films with SiNx capping layers was improved compared to those without the capping layers.

• Journal of Information Display
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• 제9권4호
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• pp.6-10
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• 2008

In this study, the selective-wettability-inscription (SWI) technique for the wet-etchingless fabrication of surface microstructures applicable to wide-viewing liquid crystal displays (LCDs) on plastic substrates was demonstrated. On the basis of the selective wetting of the photopolymer, the bi-level microstructures were spontaneously formed to serve as spacers for maintaining uniform cell gap and protrusions for the generation of multi-domains. The LC cell that has bi-level microstructures shows good extinction in the field-off state and a wide-viewing property in the field-on state. The SWI technique would be useful for the fabrication of flexible displays on plastic substrates.

• 반도체디스플레이기술학회지
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• 제11권3호
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• pp.27-31
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• 2012

This paper presents a study on the design of photovoltaic system with reversal tracking reflector. The reversal tracking reflector is conceptually designed by using TRIZ. The 20 to 30% of incident rays cannot produce the current and reflected back to the glass surface because of high refractive index of solar cell which are produced from Si, GaAs. The solution of this problem has been derived using 6SC(6 steps creativity)TRIZ. The reflector which has the actuator can be trackback the sun. Reversal tracking reflector which mounted on the top of the system prevents the shadowing loss and improve the efficiency of track back function. The anti-glare reflector prevents the heat due to the concentrated reflected light rays.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.477-480
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• 2003

We investigated the electro-optical (EO) performances of the super twisted nematic liquid crystal display (STN-LCD) on the polyimide (PI) surface using polymer film. Monodomain alignment of the plastic STN-LCD can be observed. A stable voltage-transmittance (V-T) curve of the plastic STN-LCD was observed on the polyimide (PI) surfaces using polymer film. Also, a faster response time for the plastic STN-LCD on the polyimide (PI) surfaces using polymer film can be achieved. However, the transmittance of the plastic STN-LCD on the polyimide (PI) surfaces using polymer film decreased greatly as cell gap decreases.

• Transactions on Electrical and Electronic Materials
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• 제17권2호
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• pp.109-112
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• 2016

We demonstrated an alternative electrically controlled birefringence liquid crystal (ECB-LC) system with ion beam (IB)-irradiated yttrium gallium oxide (YGaO) alignment films using a sol-gel process. The surface roughness of the films was dependent on the annealing temperature; aggregated particles on surface were observed at lower annealing temperatures, whereas a smooth surface could be obtained with higher annealing temperatures. Higher transmittance in the visible region was observed at higher annealing temperatures. The film had an amorphous crystallographic state irrespective of the annealing temperature. Furthermore, ECB-LC cell with our IB-irradiated YGaO film yielded faster response time when compared to ECB-LC cell with rubbed polyimide. Considering the fast response time and high transmittance, the IB-irradiated YGaO-base LC system is a powerful alternative application for the liquid crystal display industry.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.942-945
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• 2006

The picture quality of a plasma display panel is very sensitive to the phosphor characteristics such as luminescence, decay time, surface properties, and even longevity of phosphor material in itself. In our previous work, the discharging characteristics in green cell of PDP were demonstrated to be enhanced by coating $Zn_2SiO_4:Mn^{2+}$ phosphors with positively charged metal oxide such as MgO. Here, $Zn_2SiO_4:Mn^{2+}$ phosphors were coated by various metal oxides for examining the coating effect on the picture quality. Specially, longevity while fabricating the panel was investigated for panel application in this work. Also the effects of ion and electron bombardment on the phosphor surface will be discussed in this work.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 추계학술대회 논문집
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• pp.287-288
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• 2015

최근 투명 산화물 전극 (TCO)은 LED, electronic display, solar cell, touch screen panel (TSP) 등 다양한 분야에 많이 사용되고 있다. TCO는 높은 광 투과도와 전도성으로 인해 여러 분야에 많이 사용되고 있으며, 특히 ITO (Sn-doped indium oxide)가 display 분야에 많이 적용되고 있다. 하지만, ITO는 투과도와 면저항의 반비례 관계를 가지므로 더 낮은 면저항이 요구되는 대면적 TSP 분야에 적용되기에는 많은 개선이 필요하다. 따라서, 본 연구에서는 metal mesh film의 연구를 통해 TSP 분야에 사용되는 ITO를 대체하고자 한다. 제작된 mesh film은 모두 면저항은 $15{\Omega}/{\square}$ 이하, 광 투과도 90% (@550nm) 이상을 나타내었다.

• Transactions on Electrical and Electronic Materials
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• 제6권2호
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• pp.73-77
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• 2005

In this study, we investigated response characteristics of liquid crystal display (LCD) with different operating mode of nematic liquid crystals (NLCs) such as 45 $^{circ} twisted nematic (TN), 67.3 $^{circ} TN and electrical controlled birefringence (ECB) on the rubbed polyimide (PI) surface with side chains. The pretilt angles generated on polyimide surfaces of the three kinds of LCD operating modes were about 12 $^{circ} that was higher than those of conventional TN-LCOs. Also, the Electro-optical (EO) performance of these LCOs showed stable condition. Low transmittance of the 45 $^{circ} TN and 67.3 $^{circ} TN cell on the rubbed PI surface were measured by using low cell gap d. The fast response time in ECB cell among the three kinds of LCD operating modes was achieved. Also, thermal ability of fast 90 $^{circ} TN-LCD was investigated. The threshold voltage and the response time of thermal stressed TN-LCOs showed the same performances on no thermal stressed TN-LCOs. There was little change of value in these TN cells. However, the transmittances of TN-LCOs on the rubbed PI surface decreased while increasing thermal stress time. Therefore, the thermal stability of TN-LCD was decreased by the high thermal stress for the long duration.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 및 기술 세미나 논문집 디스플레이 광소자
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• pp.51-52
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• 2008

A single gap transflective liquid crystal display(LCD) driven by fringe electric field in the transmissive(T) region and vertical electric field in the reflective(R) region was designed. Because the pretilt angle is formed in $53^{\circ}$ through polymerization of an UV curable reactive mesogen(RM) monomer at the surface, the effective cell retardation $(d{\Delta}n_{eff})$ value of the R region becomes half of that in the T region where the LCs are homogenously aligned. Consequently, a transflective display driven by a vertical and fringe electric field with a single cell gap and single gamma curves is realized.

• 한국미생물·생명공학회지
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• 제37권4호
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• pp.355-360
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• 2009

P. carageenovora 유래 arylsulfatase 유전자(astA)의 효모표면발현 plasmid pCTAST(7.1 kb)를 구축하여 S. cerevisiae EBY100에 형질전환하였고, 선별된 형질전환체들을 YPDG 배지에서 배양했을 때 4-methylumbelliferyl sulfate를 분해하여 형광을 보였다. 이는 효모에서 arylsulfatase가 활성형으로 생산되었음을 의미하였다. S. cerevisiae EBY100/pCTAST를 플라스크 배양했을 때 arylsulfatase 활성은 galactose가 완전히 소모된 배양 48시간째 최대 활성인 1.2 unit/mL로 나타났으며 배양 상등액에서는 활성이 나타나지 않았다. 효모 S. cerevisiae의 세포표면에서 발현된 재조합 arylsulfatase로 제조된 agarose를 agar와 시판용 agarose와 함께 ${\lambda}DNA$ HindIII marker를 사용하여 DNA 전기영동 성능을 비교 실험한 결과, agar보다는 재조합 arylsulfatase 처리로 제조한 agarose가 이동성이나 분리능에서 우수하였으며, 시판용 agarose와 비교하여 이동성이나 분리능이 유사한 결과를 확인할 수 있었다. 본 연구의 결과, 효모 S. cerevisiae의 세포표면에서 발현된 재조합 arylsulfatase 효소를 이용하여 한천으로부터 전기영동용 고순도 친환경적인 agarose 생물 생산 공정에 적용 가능함을 알 수 있었다.