• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.1
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• pp.61-66
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• 2002

A method for designing antireflection (AR) and antistatic (AS) coating layer by the use of conducting polymer as an electrically conductive transparent layer is proposed. The conducting AR coating is composed of four-layer with alternating high and low refractive index layer: silicon dioxide (n=1.44) and titanium dioxide (n=2.02) prepared at low temperature by sol-gel method are used as the low and high refractive index layer, respectively. The poly(3,4-ethylenedioxythiophene) which has the surface resistivity of 10$^4$Ω/$\square$ is used as a conductive layer. Optical constant of each ARAS coating layers such as refractive index and optical thickness were measured by 7he spectroscopic ellipsometer and from the measured optical constants the spectral properties such as reflectance and transmittance were simulated in the risible region. The reflectance of ARAS films on glass substrate was below 1 %R and the transmittance was higher than 95 % in the visible wavelength (400-700 nm). The measured AR spectral properties was very similar to its simulated results.

• Journal of the Korean institute of surface engineering
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• v.53 no.4
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• pp.182-189
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• 2020

Indium tin oxide (ITO) used a transparent electrode of a photoelectric device has a low sheet resistance and a high transmittance. However, ITO is disadvantageous in that the process cost is expensive, and the process time is long. Silver nanowires (AgNWs) transparent electrodes are based on a low cost solution process. In addition, it has attracted attention as a next-generation transparent electrode material that replaces ITO because it has similar electrical and optical characteristic to ITO, it is noted as a. AgNW thin films are mainly produced by spin-coating. However, the spin-coating process has a disadvantage of high material loss. In this study, the material loss was reduced by using about 2~10 ㎕ of AgNW solution on a (25 × 25) ㎟ substrate using the shear-coating method. It was also possible to align AgNWs in the drag direction by dragging the meniscus of the solution. The electro-optical properties of the AgNW thin film were adjusted by changing the experimental parameters that the amount of AgNWs suspension, the gap between the substrate and the blade, and the coating speed. As a result, AgNW thin films with a transmittance of 90.7 % at a wavelength of 550 nm and a sheet resistance of 15 Ω/□ was deposited and exhibited similar properties to similar AgNW transparent electrodes studied by other researchers.

• Journal of the Korean Ceramic Society
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• v.37 no.3
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• pp.288-293
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• 2000

Effects of contact damage and residual stress for two kinds of dental restorative layered ceramics, porcelain/alumina and porcelain/zirconia bilayers, were observed with Hertzian and Vickers indentation methods. Indentation stress-strain behavior of each material, strength degradation of the coating material, and crack propagation behavior in the coating layer after Vickers indentation were examined by an optical microscope. As a result, porcelain as coating materials showed the classical brittleness. It was inferred that damage and strength in two bilayer system were dependent on thermal expansion mismatch between the coating material and the substrate, which affected the strength degradation. Residual stress resulting from thermal expansion mismtch was formed in the coating layer, and specially in the case of porcelain/zirconia, residual stress was eliminated as coating thickness decreased.

• Journal of information and communication convergence engineering
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• v.10 no.3
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• pp.295-299
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• 2012

Defect generation during organic bottom anti-reflective coating (BARC) in the photo lithography process is closely related to humidity control in the BARC coating unit. Defects are related to the water component due to the humidity and act as a blocking material for the etching process, resulting in an extreme pattern bridging in the subsequent BARC etching process of the poly etch step. In this paper, the lower limit for the humidity that should be stringently controlled for to prevent defect generation during BARC coating is proposed. Various images of defects are inspected using various inspection tools utilizing optical and electron beams. The mechanism for defect generation only in the specific BARC coating step is analyzed and explained. The BARC defect-induced gate pattern bridging mechanism in the lithography process is also well explained in this paper.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.5
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• pp.37-43
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• 2013

This study was focused on applying a new paper coating binder, vinyl acetate-ethylene(VAE) emulsion, with SB-latex and acrylic emulsion for paper coating application. VAE emulsion has a low monomer cost and is non-toxic chemical than conventional adhesive for paper coating such as styrene-butadiene latex( SB-latex) and acrylic emulsion. We conducted double coating in order to test VAE emulsion, which was applied on top surface only. The results showed that optical properties of the coated paper with VAE were similar with the SB-latex binders. In case of bonding strength, dry-pick of the coated paper with VAE showed almost same with other binders while wet-pick of the coated paper with VAE had a little bit lower strength than that with SB-latex.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.465-470
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• 2006

Coating are needed on ophthalmic lenses to enhance both the mechanical durability of the relatively soft plastic surface and the optical performance of lenses. Organic-inorganic hybrid materials as molar ratio of 3-glycidoxypropyltrimethoxysilane(GPTS), methyltrimethoxysilane(MTMS) and tetraethyl orthosilicate(TEOS) were used to improve the surface characteristics and the optical properties on allyl diglycol carbonate lenses. Coating for these plastics were at $140^{\circ}C$ for 4hrs, applied using the sol-grl process flow-coating technique. The coated lens properties of transmittance, adhesion, pencil hardness, abrasion resistance, hot water resistance and chemical resistance were investigated. The optimum properties was obtained when the ratio of GPTS : MTMS : TEOS was 1:1:2, respectively.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.12
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• pp.28-32
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• 2010

Technical demands for aspheric glass lens formed in market increases its application from simple camera lens module to fiber optics connection module in optical engineering. WC is often used as a metal core of the aspheric glass lens, but the long life time is issued because it fabricated in high temperature and high pressure environment. High hard thin film coating of lens core increases the core life time critically. Diamond Like Carbon(DLC) thin film coating shows very high hardness and low surface roughness, i.e. low friction between a glass lens and a metal core, and thus draw interests from an optical manufacturing industry. In addition, DLC thin film coating can removed by etching process and deposit the film again, which makes the core renewable. In this study, DLC films were deposited on the SiC ceramic core. The process variable in FVA(Filtered Vacuum Arc) method was the substrate bias-voltage. Deposited thin film was evaluated by raman spectroscopy, AFM and nano indenter and measured its crystal structure, surface roughness, and hardness. After applying optimum thin film condition, the life time and crystal structure transition of DLC thin film was monitored.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.32 no.4
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• pp.41-48
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• 2000

The main objective of this study was to investigate the packing state and optical properties of coated paper prepared with different coating colors by varying the blending ratio of such pigment as clay, $CaCO_3$, and plastic pigment. To evaluate the effect of packing state of pigment on the properties of coated paper, the coating thickness, which was theoretically calculated by specific gravity, and packing volume of pigment were used. It was found that there exists close relationship between the coating thickness and surface property of coated paper. For instance, the macro roughness(smoothness) of coated paper is closely related to bulkiness. Plastic pigments used in this research has a high finishing efficiency on the light weight coatings. Especially, hollow sphere pigment was very effective for improving the property of coated paper produced in this test. And when HSP was blended with $CaCO_3$the surface property such as smoothness and gloss improved significantly.

• Journal of the Korean Solar Energy Society
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• v.35 no.4
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• pp.9-15
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• 2015

Black cobalt solar selective coatings were prepared by using an electroplating method. The changes in the optical properties of the black cobalt selective coating due to thermal degradation were analyzed by using the Auger electron spectroscopy (AES) and spectrophotometer. The black cobalt selective coating was prepared on a copper substrate by using a synthesized electrolyte with $CoCl_2$ and KSCN at a current density of ${\sim}0.5A/dm^2$ for 45s ~ 60s. Its optical properties were a solar absorptance (${\alpha}$) of the order of 0.80 ~ 0.84 and a thermal emittance (${\epsilon}$) of 0.01. From the AES depth profile analysis of heated sample, thermal degradation of the black cobalt selective coating heated for 33 hours at temperature of $350^{\circ}C$ occurred primarily due to interdiffusion at interface of cobalt and copper substrate. This results were predictable that the ${\alpha}$ decreases due to the thermal oxidation and diffusion.

• Korean Journal of Optics and Photonics
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• v.13 no.5
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• pp.396-399
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• 2002

Using a bi-layer anti-reflection coating of $TiO_2$and $SiO_2,$ we have achieved a minimum facet reflectivity of $~10^{-5}$ and a band width of 27 nm for a reflectivity of $~10^{-4}$ or less for 1.3 $\mu\textrm{m}$ spot size converter integrated semiconductor lasers. This coating is applicable to external-cavity-tuned laser sources and semiconductor optical amplifiers.