• Korean Journal of Materials Research
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• v.19 no.9
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• pp.499-503
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• 2009

Transparent ITO films were deposited on a polycarbonate substrate with RF magnetron sputtering in a pure argon (Ar) and oxygen ($O_2$) gas atmosphere, and then post deposition electro annealed for 20 minutes in a $4{\times}10^{-1}$ Pa vacuum. Electron bombardment with an accelerating voltage of 100 V increased the substrate temperature to $120^{\circ}C$. XRD analysis of the deposited ITO films did not show any diffraction peaks, while electro annealed films indicated the growth of crystallites on the (211), (222), and (400) planes. The sheet resistance of ITO films decreased from 103 to $82{\Omega}/\square$. The optical transmittance of ITO films in the visible wavelength region increased from 85 to 87%. Observation of the work function demonstrated that the electro-annealing increased the work function of ITO films from 4.4 to 4.6 eV. The electro annealed films demonstrated a larger figure of merit of $3.0{\times}10^{-3}{\Omega}^{-1}$ than that of as deposited films. Therefore, the electro annealed films had better optoelectrical performances than as deposited ITO films.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.2
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• pp.31-35
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• 2014

The thickness dependent electrical, structural, and optical properties of ZnO films grown by atomic layer deposition (ALD) at various growth temperatures were investigated. In order to deposit ZnO films, diethylzinc and deionized water were used as metal precursor and reactant, respectively. ALD process window was found at the growth temperature range from $150^{\circ}C$ to $250^{\circ}C$ with a growth rate of about $1.7{\AA}/cycle$. The electrical properties were studied by using van der Pauw method with Hall effect measurement. The structural and optical properties of ZnO films were analyzed by using X-ray diffraction, field emission scanning electron microscopy, and UV-visible spectrometry as a function of thickness values of ZnO films, which were selected by the lowest electrical resistivity. Finally, the figure of merit of ZnO films could be estimated as a function of the film thickness. As a result, this investigation of thickness dependent electrical, structural, and optical properties of ZnO films can provide proper information when applying to optoelectronic devices, such as organic light-emitting diodes and solar cells.

• Fire Science and Engineering
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• v.26 no.2
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• pp.69-74
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• 2012

Thermal imaging technology based on IR sensor with high transmittance through the fire smoke is considered as one of the advanced technology for the fire service. The present study has been performed to investigate the image saturation characteristics with thermal condition of target and background and evaluate the performance of image quality based on the contrast transfer function (CTF). For the present testing conditions, TIC using BST sensor did not show the image saturation and the image quality based on the CTF was proportional to the temperature difference between target and background. This study can be utilized as preliminary study to improve reliability and technical development of TIC.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.450-450
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• 2007

Indium tin oxide (ITO), which is used as an electrode in organic thin film transistors (OTFT), was modified with a self-assembled monolayer (SAM) by wet chemical surface modification. The surface of the ITO was treated by dipping method in a solution of 2-chloroethane phosphonic acid (2-CEPA) at room temperature. The work function in the ITO which was modified with the SAM in the 2-CEPA had 5.43eV. A surface energy and a transmittance were unchanged in an error range. On this study, therefore, possibility of ohmic contact is showed in the interface between the ITO and the organic semiconductors. These results suggest that the treatment of the ITO with the SAM can greatly enhance the performance of the OTFT.

• Korean Journal of Materials Research
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• v.24 no.12
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• pp.715-719
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• 2014

(PDDA/$SiO_2$) thin films that consisted of positively charged poly (diallyldimethylammonium chloride) (PDDA) and negatively charged $SiO_2$ nanoparticles were fabricated on a glass substrate by an applying voltage layer-by-layer (LBL) self-assembly method. In this study, the microstructure and optical properties of the (PDDA/$SiO_2$) thin films coated on glass substrate were measured as a function of the applied voltage on the Pt electrodes. When 1.0 V was applied to a Pt electrode in a PDDA and $SiO_2$ solution, the thickness of the $(PDDA/SiO_2)_{10}$ thin film increased from 79 nm to 166 nm. The surface roughness also increased from 15.21 nm to 33.25 nm because the adsorption volume of the oppositely charged PDDA and $SiO_2$ solution increased. Especially, when the voltage was applied to the Pt electrode in the $SiO_2$ solution, the thickness increase of the (PDDA/$SiO_2$) thin film was larger than that obtained when using the PDDA solution. The refractive index of the fabricated (PDDA/$SiO_2$) thin film was ca. n = 1.31~1.32. The transmittance of the glass substrate coated by (PDDA/$SiO_2$)6 thin film with a thickness of 106 nm increased from ca. 91.37 to 95.74% in the visible range.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.126.2-126.2
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• 2011

ZnS thin films were deposited with the radio frequency magnetron sputtering technique at various temperatures and sputtering powers. With the increase in the deposition temperature and the decrease in the radio frequency sputtering power, the crystallinity was increased and the surface roughness was decreased, which lead to the decrease in the electrical resistivity of the film. It is also clearly observed that, the intensity of the (111) XRD peak increases with increasing the substrate temperature. On the other hand, as seen in the FWHM decreased with increasing the substrate temperature. Since the FWHM of the (111) diffraction peak is inversely properties to the grain size of the film, then grain size of ZnS thin film increases with increasing the substrate temperature. The electrical resistivity and optical transmittance of the ZnS film as a function of the post-annealing temperature. It can be seen that with the annealing temperature set at $400^{\circ}C$, the resistivity decreases to a minimum value of $2.1{\times}10^{-3}\;{\Omega}cm$ and the transmittance increases to a maximum value of 80% of the ZnS film.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.5
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• pp.903-910
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• 1997

Vit. D3 was measured which was produced by UVB irradiation to provit. D3, 7-d ehyd rock o 1 cst or of (7-DH Cl Measuring the amount of vie. D3 when it was irradiated to the fabrics which had different UV8 transmittance, production of vile. Ds by UVB(Ultraviolet B) and inhibition from formation of vile. D3 by fabrics were absorbed and followings are the results. As the amount of irradiated compared UVB increased, the amount of the production of vile. D3 produced by UVB irradiation from 7-DHC was increased. After treatment of 7-DHC by UVB irradiation and incubated respectively for 24hr, 48hr and 72hr at 36.5$^{\circ}C$ The amount of lit. D3 was increased as incubating time passed. When irradiated UVB on 7-DHC, intermediate of vile. D3, lumisterol, tachysterol and previt. D were showed and those materials were seemed to be changed to vile. D3 as incubation time passed. The amount of vile. D3 which was produced by irradiation 7-DHC showed close relation with UVB transmittance rate of summer fabrics (r= 0.987). Clothes, hats, and sun screen cream reduce the amount of vile. D3 Produced naturally in human skin and it result the decrease of calcium in blood which is absorbed through vit. D. Those all can cause or worsen osteomalacia especially to women and the aged people. Therefore, it is necessary to research and to develop function oriented clothing which can transmit UV which produce vile. D3 at the same time which can protect toxical UVB.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.217.2-217.2
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• 2014

We prepared a flexible and transparent CuO/Cu/CuO multilayer electrodes on a polyethylene terephthalate (PET) substrate using a specially designed roll-to-roll sputtering system at room temperature for GFF-type touch screen panels (TSPs). By the continuous roll-to-roll sputtering of the CuO and Cu layer, we fabricated a flexible CuO(150nm)/Cu(150nm)/CuO(150nm) multilayer electrodes with a sheet resistance of $0.289{\Omega}/square$, resistivity of $5.991{\times}10^{-23}{\Omega}-cm$, at the optimized condition without breaking the vacuum. To investigate the feasibility of the CuO/Cu/CuO multilayer as a transparent electrode for GFF-type TSPs, we fabricated simple GFF-type TSPs using the diamond patterned CuO/Cu/CuO electrode on PET substrate as function of mesh line width. Using diamond patterned CuO/Cu/CuO electrode of mesh line $5{\mu}m$ with sheet resistance of 38 Ohm/square, optical transmittance of 90% at 550 nm and an average transmittance of 89% at wavelength range from 380 to 780 nm, we successfully demonstrated GFF-type touch panel screens (TPSs). The successful operation of GFF-type TPSs with CuO/Cu/CuO multilayer electrodes indicates that the CuO/Cu/CuO multilayer is a promising transparent electrode for large-area capacitive-type TPSs due to its low sheet resistance and high transparency.

• Journal of the Optical Society of Korea
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• v.17 no.4
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• pp.344-349
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• 2013

This paper proposes a simulation algorithm to assess the gradual yellowing vision of the elderly, which refers to the predominance of yellowness in their vision due to aging of the ocular optic media. This algorithm employed the spectral transmittance property of a yellow filter to represent the color appearance perceived by elderly people with yellow vision, and modeled the changes in the color space through a spectrum change in light using the yellow filter effect. The spectral reflectivity data of 1269 Munsell matte color chips were used as reference data. Under the standard conditions of a D65 illuminant and a $10^{\circ}$ observer of 1964 CIE, the spectrum of the 1269 Munsell colors were processed through the yellow filter effect to simulate yellow vision. Various degrees of yellow vision were modeled according to the transmittance percentage of the yellow filter. The color differences before and after the yellow filter effect were calculated using the DE2000 formula, and the color pairs were selected based on the color difference function. These color pairs are distinguishable through normal vision, but the color difference diminishes as the degree of yellow vision increases. Assuming 80% of yellow vision effect, 17 color pairs out of $(1269{\times}1268)/2$ pairs were selected, and for the 90% of yellow vision effect, only 3 color pairs were selected. The result of this study can be utilized for the diagnosis system of gradual yellow vision, making various types of test charts with selected color pairs.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.6
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• pp.251-257
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• 2020

In order to quickly and clearly recognize characters or images through display glass, glare of the glass must be suppressed. In this study, we tried to reduce glare by analyzing changes in glass surface shape and optical properties through etching process. The etching process was performed as a function of concentrations of the etching solutions, BOE and HF. During the etching process, a compound containing F ion was generated on the surface of the glass, forming an irregular pattern in the form of a projection, and thus various optical properties of the glass were changed; reflectance of 2.5~4.6 %, haze of 4.5~6.6 %, transmittance of 77~92 %, and gloss of 82~107 GU. As a result, optimum etching condition was obtained to minimize the loss of other optical properties while suppressing glare of the glass.