• Applied Chemistry for Engineering
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• v.30 no.3
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• pp.358-364
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• 2019

To improve the optical characteristics and antifouling of anti-reflective coating (AR) films, various AR coating films were prepared by varying the mixing ratio of tetraethylorthosilicate (TEOS)/base and methyltrimethoxysilane (MTMS)/acid hybrid solution. Prepared AR coating films were characterized by UV-Vis spectroscopy, contact angle analyzer, atomic force microscope (AFM), FT-IR and pencil scratch hardness test. In an AR coating film that prepared from the hybrid solution with a 10 wt% MTMS/acid solution, the glass substrate showed an excellent optical property (97.2% transmittance), good antifouling ($121^{\circ}$ water contact angle and $90^{\circ}\;CH_2I_2$ contact angle) and moderate mechanical strength (pencil hardness of 4 H). In particular, it is considered that the good antifouling was due to the well dispersion of the methyl group ($-CH_3$), derived from a small amount of MTMS/acid solution in the hybrid solution, on the substrate surface. From results of the pencil hardness test, the mechanical strength of AR coating film was improved as the content of MTMS/acid solution increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.200-201
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• 2008

태양전지 제작 시 반사방지막(Anti-reflection Coating)이 태양전지 효율에 미치는 영향을 알아보기 위한 실험으로 최적의 가스비를 알아보기 위하여 Plasma Enhanced Chemical Vapor Deposition(PECVD)를 이용한 Silicon nitride 증착 실험이다. SiH4 가스를 45 sccm으로 고정시킨 상태에서 NH3를 25,45,60,90,135 sccm으로 가변하여 Carrier Lifetime과 Refractive index를 측정하였다. PECVD의 조건은 기판온도 $450^{\circ}C$, Chamber 압력 1 Torr, 증착두께 $1000\AA$으로 고정하였다. 증착 후 500, 600, 700, $800^{\circ}C$로 열처리를 하고나서 Carrier Lifetime을 측정하여 열처리에 대한 효과도 알아보았다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.12a
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• pp.103-106
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• 2006

Semiconductor laser diode has a reflective facet in a both-ends side fundamentally. Laser performance for improving, Anti-Reflection and High-reflection coating on the facet of semiconductor laser diode. To prevent internal feedback from both facets for realizing superluminescent diode and reducing the reflection-induced intensity noise of laser diode, it's key techniques are AR/HR coatings. In the study AR coating film were manufactured by Ion-Assisted Deposition(IAD) system. Then manufactured coating film measurement electrical properties(L-I-V, Se, Resistor) and Optical properties (wavelength FFP)

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.111.2-111.2
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• 2012

정보 기술 시대에 맞춰 광전소자의 연구가 활발해지면서 투명전극으로 사용될 수 있는 Transparent Conductive Oxide (TCO) 재료에 대한 관심이 높아지고 있다. 하지만 TCO의 대표적인 물질인 Indium Tin Oxide (ITO)의 경우 In의 가격 상승으로 인해 최근에는 낮은 전도도와 높은 투과도를 가질 수 있는 대체 물질에 대한 연구가 활발히 진행되고 있다. 그 중에서 3.2 eV 의 높은 밴드갭을 갖는 ZnO 는 가시광선 영역에서 높은 투과율을 나타낼 뿐만 아니라 Al, Ga을 도핑함으로써 낮은 전도도를 가질 수 있다. 이러한 TCO 재료는 surface texturing을 통하여 optical region 에서 반사를 억제 시킴으로서 빛을 모으는 역할을 하여 태양전지의 효율을 향상 시킬 수 있기 때문에 PV (Photovoltaics) Cell의 anti-reflective coating에 적용 할 수 있다. 본 연구에서는 pulsed DC magnetron sputtering을 이용하여 Ga-doped ZnO (GZO) 박막을 증착하였고, HCl 0.5 wt %로 wet etching을 통하여 surface texturing을 진행하였다. 결정성은 X-ray diffractometer (XRD)로 분석하였으며, 표면 형상은 Scanning Electron Microscope (SEM)을 통해 확인하였다. Van der Pauw 방법을 통해 resistivity, carrier concentration, hall mobility 등의 전기적 특성을 분석하였고 UV-Vis spectrophotometer 를 통해 투과도 및 반사도를 측정하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.449-449
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• 2007

OLED has many advantages of low voltage operation, self radiation, light weight, thin thickness, wide view angle and fast response time to overcome existing liquid crystal display (LCD)'s weakness. Therefore, It draws attention as promising display and has already developed for manufactured goods. Also, OLED is regarded as a only substitute of flexible display with a thin display. A considerable portion of the light originating film emissive centers buried in a solid film never escapes due to internal reflection at the air-film interface and is scattered as edge emission or dissipated within the solid film This is one of the major reasons why the luminous power efficiency of OLED remains low, in spite of research progress in OLED. Although several ways of overcoming this difficulty have been reported, no comprehensive method has been proposed yet. In this paper, we propose that use of anti-reflective coating layers.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.10a
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• pp.217-220
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• 2009

This paper presents fabrication method of nano-structured PMMA substrates as well as evaluations of their optical transmittance. For anti-reflective surface, surface coating method had been conventionally used. However, it requires high cost, complicated process and post-processing times. In this study, we suggested the fabrication method of anti-reflective surface by the hot embossing process. Using the nano patterned master fabricated by anodic aluminum oxidation process. Anodic aluminum oxide(AAO) is widely used as templates or a molds for various applications such as carbon nano tube (CNT), nano rod and nano dots. Anodic aluminum oxidation process provides highly ordered regular nano-structures on the large area, while conventional pattering methods such as E-beam and FIB can fabricate arbitrary nano-structures on small area. We fabricated a porous alumina hole array with various inter-pore distance and pore diameter. In order to replicate nano-structures using alumina nano hole array patterns, we have carried out hot-embossing process with PMMA substrates. Finally the nano-structured PMMA substrates were fabricated and their optical transmittances were measured in order to evaluate the charateristivs of anti-reflection. Anti-reflective structure can be applied to various displays and automobile components.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.18 no.6
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• pp.697-701
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• 2009

A simple method for the fabrication of porous nano-master for the anti-reflection effect on the transparent substrates is presented. In the conventional fabrication methods for antireflective surface, coating method using materials with low refractive index has usually been used. However, it is required to have a high cost and long processing time for mass production. In this paper, we developed a porous nano-master with anti-reflective surface for the molding stamper of the injection mold, hot embossing and UV imprinting by using the aluminum anodizing process. Through two-step anodizing and etching processes, a porous nano-master with anti-reflective surface was fabricated at the large area. Pattern size Pore diameter and inter-pore distance are about 130nm and 200nm, respectively. In order to replicate anti-reflective structure, hot embossing process was performed by varying the processing parameters such as temperature, pressure and embossing time etc. Finally, antireflective surface can be successfully obtained after etching process to remove selectively silicon layer of AAO master.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.90.2-90.2
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• 2010

The crystalline silicon solar cells have been optical losses. but it can be reduced using light trapping by texture structure and anti-reflection coating. The high reflective index of crystalline silicon at solar wavelengths(400nm~1000nm) creates large reflection losses that must be compensated for by applying anti-reflection coating. In this study, the use of porous silicon(PSi) as an active material in a solar cell to take advantage of light trapping and blue-harvesting photoluminescence effect. Porous silicon is form by anodization and can be obtained in an electrolyte with hydrofluoric. We expect our research can results approaching to lower than 10% of several reflectance by porous silicon solar cells.

• Applied Science and Convergence Technology
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• v.23 no.1
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• pp.27-33
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• 2014

We have studied photovoltaic characteristics of single-junction GaAs solar cells with/without an $MgF_2/ZnS$ anti-reflective coating (ARC) illuminated by low-density concentration (<10 suns). By the ARC deposition, the short-circuit current density ($J_{SC}$) and the fill factor (FF) are increased by $5mA/cm^2$ and 5% at a standard illumination (1 sun), respectively, and the resulted conversion efficiency is enhanced by 45%. In contrast with the cell with no ARC showing a rapid degradation with increasing concentration power, the efficiency of ARC-deposited cell remains almost constant as ($17.7{\pm}0.3$)% regardless of the concentration. It informs that ARC treatment is very effective in GaAs concentrator solar cells.

• Journal of the Korean institute of surface engineering
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• v.50 no.5
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• pp.345-351
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• 2017

A double-layered anti-reflective coating with hydrophilic/abrasion-resistant properties was studied using anatase titanium dioxide($TiO_2$) and silicon oxycarbide($SiO_xC_y$) thin film. $TiO_2$ and $SiO_xC_y$ thin films were sequentially deposited on a glass substrate by DC sputtering and PECVD, respectively. The optical properties were measured by UV-Vis-NIR spectrophotometer. The abrasion-resistance and the hydrophilicity were observed by a taber abrasion tester and a contact angle analyzer, respectively. The $TiO_2/SiO_xC_y$ double-layer thin film had an average transmittance of 91.3%, which was improved by 10% in the visible light region (400 to 800 nm) than that of the $TiO_2$ single-layer thin film. The contact angle of $TiO_2/SiO_xC_y$ film was $6.9^{\circ}$ right after UV exposure. After 9 days from the exposure, the contact angle was $10.2^{\circ}$, which was $33^{\circ}$ lower than that of the $TiO_2$ single-layer film. By the abrasion test, $SiO_xC_y$ film showed a superior abrasion-resistance to the $TiO_2$ film. Consequently, the $TiO_2/SiO_xC_y$ double-layer film has achieved superior anti-reflection, hydrophilicity, and abrasion resistance over the $TiO_2$ or $SiO_xC_y$ single-layer film.