• Journal of the Korean Society for Heat Treatment
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• v.24 no.6
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• pp.307-310
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• 2011

We have investigated the structural, electrical and optical properties of $In_2O_3$ thin films deposited by RF magnetron sputtering and then annealed at $150^{\circ}C$ and $300^{\circ}C$ in vacuum. The structural and electrical properties are strongly related to annealing temperature. All the annealed $In_2O_3$ films are grown as a hexagonal wurtzite phase and the largest grain size is observed in the films annealed at $300^{\circ}C$. The sheet resistance decreases with a increase in annealing temperature and $In_2O_3$ film annealed at $300^{\circ}C$ shows the lowest sheet resistance of $174{\Omega}/{\Box}$. The optical transmittance of $In_2O_3$ films in a visible wavelength region also depends on the annealing temperature. The films annealed at $300^{\circ}C$ show higher transmittance of 76% than those of the films prepared in this study.

• Transactions on Electrical and Electronic Materials
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• v.10 no.5
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• pp.165-168
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• 2009

Transparent and conducting ITO/Cu/ITO multilayered films were deposited by magnetron sputtering on unheated polycarbonate (PC) substrates. The thickness of the Cu intermediate film was varied from 5 to 20 nm. Changes in the microstructure and optoelectrical properties of ITO/Cu/ITO films were investigated with respect to the thickness of the Cu intermediated layer. The optoelectrical properties of the films were significantly influenced by the thickness of the Cu interlayer. The sandwich structure of ITO 50 nm/Cu 5 nm/ITO 45 nm films had a sheet resistance of $36{\Omega}$/Sq. and an optical transmittance of 67% (contain substrate) at a wavelength of 550 nm, while the ITO 50 nm/Cu 20 nm/ITO 30 nm films had a sheet resistance of $70{\Omega}$/Sq. and an optical transmittance of 36%. The electrical and optical properties of ITO/Cu/ITO films were determined mainly by the Cu film properties. From the figure of merit, it is concluded that the ITO/Cu/ITO films with a 5 nm Cu interlayer showed the better performance in transparent conducting electrode applications than the conventional ITO films.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.2
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• pp.91-95
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• 2019

A new experimental approach is proposed to detect a specific polymer dissolved in a liquid. Distinctive optical properties were found using a laser scattering technique when there is a polymer compound with almost no difference in optical properties (index of refraction) in a liquid phase. The index of refraction, which determines the refraction of light, is obtained by dissolving PCL and PLA. The used samples are biodegradable materials with similar properties and dissolved in a mixture of Chloroform 7: Methanol 3. To predict the optical properties, a 632-nm diode laser was used as the light source of the device, and an integrating sphere was used as the light receiver. Although PCL and PLA had a similar index of refraction of 1.46-1.48, the dissolved PCL showed a relative transmittance of 43%, and the dissolved PLA had a relative transmittance of 34%. The difference in optical properties of the pure polymer compound in the solid state or liquid state is not significantly different, and the difference in the dissolved state in the specific solvent is remarkable because the solubility differs in a specific solution and is randomly distributed.

• Journal of the Korean institute of surface engineering
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• v.52 no.3
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• pp.145-149
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• 2019

Transparent and conductive ZnO/Ag/SnO2 (ZAS) tri-layer films were deposited onto glass substrates at room temperature by using radio frequency (RF) and direct current (DC) magnetron sputtering. The thickness values of the ZnO and $SnO_2$ thin films were kept constant at 50 nm and the value for Ag interlayer was varied as 5, 10, 15, and 20 nm. In the XRD pattern the diffraction peaks were identified as the (002) and (103) planes of ZnO, while the (111), (200), (220), and (311) planes could be attributed to the Ag interlayer. The optical transmittance and electrical resistivity were dependent on the thickness of the Ag interlayer. The ZAS films with a 10 nm thick Ag interlayer exhibited a higher figure of merit than the other ZAS films prepared in this study. From the observed results, a ZAS film with a 10 nm thick Ag interlayer was believed to be an alternative transparent electrode candidate for various opto-electrical devices.

• Transactions on Electrical and Electronic Materials
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• v.13 no.5
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• pp.241-244
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• 2012

Antimony doped tin oxide (ATO) thin films on glass substrate were prepared by the chemical solution deposition (CSD) method, using sol-gel solution synthesized by non-alkoxide precursors and the sol-gel route. The crystallinity and electrical properties of ATO thin films were investigated as a function of the annealing condition (both annealing environments and temperatures), and antimony (Sb) doping concentration. Electrical resistivity, carrier concentration, Hall mobility and optical transmittance of ATO thin films were improved by Sb doping up to 5~8 mol% and annealing in a low vacuum atmosphere, compared to the undoped tin oxide counterpart. 5 mol% Sb doped ATO film annealed at $550^{\circ}C$ in a low vacuum atmosphere showed the highest electrical properties, with electrical resistivity of about $8{\sim}10{\times}10^{-3}{\Omega}{\cdot}cm$, and optical transmittance of ~85% in the visible range. Our research demonstrates the feasibility of low-cost solution-processed transparent conductive oxide thin films, by controlling the appropriate doping concentration and annealing conditions.

• Journal of Magnetics
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• v.8 no.4
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• pp.133-137
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• 2003

The magnetostatic properties of the as-deposited and annealed at T=300 and 400$^{\circ}C$ Ni films were investigated employing both magneto-optical magnetometer and VSM. The Ni films of 50∼200 nm thicknesses were prepared by DC magnetron sputtering technique. The strong influence of annealing temperature on magnetostatic properties of the studied samples was discovered. For the annealed Ni films, the increase of the coercivity H$_c$ (up to 4 times) in comparison with that of as-deposited samples was revealed. The obtained results were explained by using crystallographic structural data of the samples.

• Transactions on Electrical and Electronic Materials
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• v.14 no.2
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• pp.82-85
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• 2013

This paper introduces 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS pentacene) doped liquid crystal (LC) alignment properties on a rubbed polyimide (PI) layer as a function of the doping concentration of TIPS pentacene. Pretilt angles, photomicrographs, and electro-optical properties of TIPS pentacene doped LCs were comparable to those of pure LCs. However, TIPS pentacene in a LC medium supported twisted nematic-liquid crystal displays (TN-LCDs) to improve electro-optical properties. The threshold voltages observed in the TN cells decreased as the TIPS pentacene concentration increased. In addition, suitable response times were observed in TN cells.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.9-14
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• 1996

The dependence of microstructural and optical properties of Ag-In-Sb-Te thin films on annealing heat-treatments was studied. It was found from the present work that the increase of reflectance after annealing heat-treatment is related with phase change of Ag-In-Sb-Te thin film from amorphous state to crystalline phases which involve Sb crystalline phase and AgInTe$_2$ stoichiometric phase. On the other hand, the reflectance is decreased after high temperature annealing (above 450$^{\circ}C$), due to the morphology .mange of film surface. For the purpose of practical application(erasable optical disk), we fabricated quadrilayered Ag-In-Sb-Te alloy disk, and annealed it with continuous laser beam. As result of this laser\ulcorner annealing treatment, we found that the increment of reflectance is 9.3% at 780nm wavelength. It might be considered that Ag-In-Sb-Te alloy optical disk is the big promising candidate for the erasable optical memory medium.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.68.1-68.1
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• 2012

The best part of graphene is - charge-carriers in it are mass less particles which move in near relativistic speeds. Comparing to other materials, electrons in graphene travel much faster - at speeds of $10^8cm/s$. A graphene sheet is pure enough to ensure that electrons can travel a fair distance before colliding. Electronic devices few nanometers long that would be able to transmit charge at breath taking speeds for a fraction of power compared to present day CMOS transistors. Many researches try to check a possibility to make it a perfect replacement for silicon based devices. Graphene has shown high potential to be used as interconnects in the field of high frequency electrical devices. With all those advantages of graphene, we demonstrate characteristics of electrical and optical properties of graphene such as the effect of graphene geometry on the microwave properties using the measurements of S-parameter in range of 500 MHz - 40 GHz at room temperature condition. We confirm that impedance and resistance decrease with increasing the number of graphene layer and w/L ratio. This result shows proper geometry of graphene to be used as high frequency interconnects. This study also presents the optical properties of graphene oxide (GO), which were deposited in different substrate, or influenced by oxygen plasma, were confirmed using different characterization techniques. 4-6 layers of the polycrystalline GO layers, which were confirmed by High resolution transmission electron microscopy (HRTEM) and electron diffraction analysis, were shown short range order of crystallization by the substrate as well as interlayer effect with an increase in interplanar spacing, which can be attributed to the presence of oxygen functional groups on its layers. X-ray photoelectron Spectroscopy (XPS) and Raman spectroscopy confirms the presence of the $sp^2$ and $sp^3$ hybridization due to the disordered crystal structures of the carbon atoms results from oxidation, and Fourier Transform Infrared spectroscopy (FTIR) and XPS analysis shows the changes in oxygen functional groups with nature of substrate. Moreover, the photoluminescent (PL) peak emission wavelength varies with substrate and the broad energy level distribution produces excitation dependent PL emission in a broad wavelength ranging from 400 to 650 nm. The structural and optical properties of oxygen plasma treated GO films for possible optoelectronic applications were also investigated using various characterization techniques. HRTEM and electron diffraction analysis confirmed that the oxygen plasma treatment results short range order crystallization in GO films with an increase in interplanar spacing, which can be attributed to the presence of oxygen functional groups. In addition, Electron energy loss spectroscopy (EELS) and Raman spectroscopy confirms the presence of the $sp^2$ and $sp^3$ hybridization due to the disordered crystal structures of the carbon atoms results from oxidation and XPS analysis shows that epoxy pairs convert to more stable C=O and O-C=O groups with oxygen plasma treatment. The broad energy level distribution resulting from the broad size distribution of the $sp^2$ clusters produces excitation dependent PL emission in a broad wavelength range from 400 to 650 nm. Our results suggest that substrate influenced, or oxygen treatment GO has higher potential for future optoelectronic devices by its various optical properties and visible PL emission.

• Journal of the Korean Society of Industry Convergence
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• v.4 no.1
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• pp.35-40
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• 2001

A spectral measurement system for reflection and transmission properties by using an optical fiber and an ellipsoidal mirror was newly developed. The hemispherical reflectance and transmittance spectra of several heating resisting ceramics materials were measured from visible to middle infrared region. The directional characteristics of reflection and transmission were also investigated in consideration of the absorptance. The measured data were analyzed by using a four flux model of radiation transfer, The radiation properties could be estimated by the obtained scattering and absorption coefficient spectra.