• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.4
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• pp.231-236
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• 2016

A three-electrode type reflective display (electronic paper) is designed to apply an independent electric field to each three electrodes of the cell including two electric-type of particles and electrically neutral color fluid, so single color realization is possible. In particular, the movement of particles and optical properties are decided by the electric field between two electrodes on the lower substrate. So, the effect of electric field by the distance between two electrodes on the lower substrate is studied with electrode spacing with $10{\mu}m$, $15{\mu}m$, $20{\mu}m$, and $25{\mu}m$. By our experimentation, the driving voltage induces more reliable movement of charged particles and the optical properties as compared with the threshold voltage. We ascertain the single color realization and non-inverted particle separation is possible. So the more desirable optical properties are observed in case of the short electrode like $10{\mu}m$.

• Journal of the Korean Physical Society
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• v.73 no.10
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• pp.1566-1570
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• 2018

We investigated the visible emission property of $SrTiO_3$ (STO) single crystals irradiated with gammy-ray (${\gamma}$-ray) at various total doses up to 900 kGy. The electric and optical absorption properties of the irradiated STO samples were hardly changed with the ${\gamma}$-ray irradiation, compared with those of un-irradiated STO. In contrast, the visible emission near 550 nm increased with the ${\gamma}$-ray dose increasing. While the development of the visible emission was indicative of the increase of oxygen vacancies inside STO by the ${\gamma}$-ray irradiation, the newly generated oxygen vacancies were not significantly harmful to the electric and optical properties of STO. We concluded that the STO single crystal should have a good tolerance against the damage by the ${\gamma}$-ray irradiation.

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.541-542
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• 2009

We have developed an image reversal photoresist with high thermal stability and electric insulating properties for the single isolation structure of OLEDs. The thermal stability and electric insulating properties are investigated and compared with those of conventional insulator and cathode separator materials. The single isolation structure using the image reversal photoresist reduces the fabrication process steps and cuts down the manufacturing cost.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.726-728
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• 1998

Optical and electrical properties of GaSe:$Er^{3+}$ single crystals grown by the Bridgeman technique was been investigated by using optical absorption and Hall-effect measurements. The Hall coefficients were measured by using a high impedance electrometer in the temperature range from 360K to 150K. The temperature dependence of hole concentration shows the characteristic of a partially compensated p-type semiconductor. carrier density($N_H$) of GaSe doped with Erbium was measured about $3.25{\times}10^{16}\;[cm^{-3}}$ at temperature 300K, which was high than undoped specimen. Photon energy gap ($E_{gd}$) was measured about 1.7geV.

• Journal of Sensor Science and Technology
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• v.28 no.6
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• pp.341-344
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• 2019

Liquid crystal (LC) mesophase materials manifest a variety of phase transitions. The optical properties of LCs are highly dependent upon the phase and orientation of the optical axis with respect to the polarization of incoming light. Studying the LC phase transitions is significantly important for a wide range of scientific and industrial applications. In this study, we demonstrate the propagation velocity of the phase boundary between the nematic and isotropic phase of 4-Cyano-4-pentylbiphenyl (5CB) liquid crystal for different electric fields using a polarized optical microscope. The results demonstrate that the propagation velocity of the phase boundary exhibits a peak value for a specific voltage, attributed to the supercooling of the isotropic phase of the LC. The analysis of the propagation velocity for different electric fields also provides a simple optical platform to measure the thermal anisotropy and voltage dependent thermal properties of the homogeneously aligned LC.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1509-1514
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• 2008

To fabricate microsized poly(methyl methacrylate)(PMMA) beads of uniform size and density on poly(ethylene terephthalate) (PET) fis, we introduce an electro spraying technique that uses a target electrode applied with an ac electric fid. Using the apparatus and various material properties, we could obtain uniform size PMMA beads which were deposited on the thin PET film. The optical properties, transmittance and light diffusivity of the fis electro sprayed with the PMMA were characterized. The results show that the sprayed beads appear to act as a good optical diffuser, like microlenses. To understand the effect of process variables, applied field conditions and rheological properties, the morphological pictures of the deposited particles were investigated through the optical and scanning electron microscope.

• Korean Journal of Optics and Photonics
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• v.1 no.1
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• pp.16-21
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• 1990

The accurate polarization state of the light inside BSO crystal was calculated with consideration of optical activity. By solving Maxwell's equations, the general form of the polarization matrix for any direction of the electric field was obtained. Examples of output polarization states in BSO crystals were also calculated, and their properties were discussed.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1547-1549
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• 1994

In recent years, fiberoptic technology is becoming indispensable in establishing communication networks due to its low loss, high capacity and non-inductive properties. In the power industry as well, the technology is being required to cable and facility monitering, and control system. But, duct in the manhole and space in the culvert are required to fiberoptic cable that is separated from power cable. Therefore, some cable makers and R&D has been studying the composite fiber/power cables. This report introduces the outline of ABF system, construction and properties of optical composite power cable that used ABF technology.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.6
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• pp.491-496
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• 2010

The relaxation behavior of aligned electric dipoles in a mixed polymer of P2ANS with P(VDF-TrFE) is studied with optical second harmonic generation (SHG). In this work, a macroscopic noncentrosymmetry of the spin coated film was achieved by an electrical poling. The relaxation of induced polar order of nonlinear optic(NLO) chromophores after poling leads to an insufficient long-term stability of NLO properties. In this work, we develop a new technique to suppress such kind of dipole relaxation in a poled polymer. We found that the poled dipoles in a NLO polymer were effectively immobilized by the internal electric field created by a thermally annealed ferroelectric polymer. The long-term stability in a mixed system of NLO polymer/ferroelectric polymer was successively accomplished by a series of thermal treatments applied to the mixed polymer system at a temperature of $140^{\circ}C$ for at least 1hour after poling.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.63.2-63.2
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• 2012

One-dimensional nanowires (NW)/nanorods are under intense investigation in materials science due to their potential applications in many electronic devices. Since the properties required for these applications are greatly influenced by their microscopic structures, it is important to understand the relation between the microstructures with their optical and electric properties. In this study, Ag nanowires were synthesized in various dimensions and coated onto PET films to form transparent electrode. Their optical and electrical properties were studied in terms of their microstructures. Highly transparent (>90%), low haze transparent electrode films were successfully fabricated with surface resistance as low as (~50 ${\Omega}$/>).