• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.542-547
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• 2012

We have investigated the electronic properties of the oxide film and anodic oxidation mechanism. Iron was oxidized by two reaction pathways depending on pH. The oxide film has showed the electronic properties of n-type semiconductor based on the Mott-Schottky equation.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.31-36
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• 2000

The existing theoretical models for steady two-dimensional free convective laminar film condensation or pure saturated or superheated vapor under atmospheric pressure on isotheraml vertical wall have been reviewed. To investigate the effects of inertia, thermal convective and liquid-vapor interface shear stress, the models of constant or variable properties in liquid film for condensation of saturated vapor are compared in detail with Nusselt model. Also, for condensation of superheated vapor the effects of superheated temperature and variable properties in liquid and vapor layer are examined and then new correlation is proposed to predict the heat transfer. The results are in good agreement with the Shang's correlation within 2% errors.

• Journal of the Korean institute of surface engineering
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• v.44 no.6
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• pp.255-259
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• 2011

The thickness dependence of magnetic properties was experimentally investigated in nanocrystalline Fe-Hf-N thin films fabricated by a RF magnetron sputtering method. In order to investigate the thickness effect on their magnetic properties, the films are prepared with different thickness ranges from 90 nm to 330 nm. It was revealed that the coercivity of the thin film increased with film thickness. On the contrary, the saturation magnetization decreased with film thickness. On the basis of the SEM and TEM, an amorphous phase forms during initial growth stage and it changes to crystalline structure after heat treatment at $550^{\circ}C$. Nanocrystalline Fe-Hf-N particles are also generated.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.8
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• pp.758-763
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• 2006

We has been studied the thin film encapsulation effect for organic light-emitting diodes (OLED). To evaluate the passivation properties of the passivation layer materials, we have carried out the fabrication of green light emitting diodes with ultra violet(UV) light absorbing polymer resin, $SiO_2,\;and\;SiN_x$, respectively. From the measurement results of shrinkage properties according to the exposure time to the atmosphere, we found that $SiN_x$ thin film is the best material for passivation layer. We have investigated the emission efficiency and life time of OLED device using the package structure of $OLED/SiN_x/polymer$ resin/Al/polymer resin. The emission efficiency of this OLED device was 13 lm/W and life time was about 2,000 hours, which reach 95 % of the performance for the OLED encapsulated with metal.

• Journal of the Korean Ceramic Society
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• v.36 no.5
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• pp.465-470
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• 1999

Sensing properties of $\alpha$-Fe2O3 thin film to reducing gases such as CHx and CO were systematically examined after deposition on Al2O3 substrate by PECVD(Plasma Enhanced Chemical Vapor Deposition)technique. Microstructure of deposited $\alpha$-Fe2O3 thin film showed the porous island structure. This specimen was annealed at 450, 550, $650^{\circ}C$ to enhance the gas sensing properties and investigated in terms of CO and C4H10 concentration from 500ppm to 3,000 ppm at operating temperature of 35$0^{\circ}C$ The gas sensitivity(%) to C4H10 measured at the operating temperature of 35$0^{\circ}C$ was 98.24 (highest sensitivity) 69.51 to CO and 2% to CH4 respectviely.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.12
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• pp.1072-1076
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• 2007

We prepared the Al doped ZnO (AZO) thin film on polyethersulfon (PES) without any substrate heating by Facing Targets Sputtering (FTS) system. FTS system has two different facing targets. One is ZnO doped the content of Al 2 wt% and the other is Zn in order to decrease resistivity. The electrical, structural and optical properties of AZO thin films were investigated. To evaluate the as-deposited thin film properties, we employed four-point probe (CMT-R100nw, Changmin), Surface profiler (Alpha-step, Tencor), UV/VIS spectrometer (HP), X-ray diffractometer (XRD, Rigaku) and Field Emission Scanning Electron Microscopy (FESEM, Hitachi S-4700). As a result, We obtained that AZO thin film deposited on PES substrate at a DC Power of 150 W, working pressure of 1 mTorr and $O_2$ gas flow ratio of 0.2 exhibited the resistivity of $4.2{\times}10^{-4}\;[{\Omega}cm]$ and the optical transmittance of about 85 % in the visible range.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.85-86
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• 2007

A poly(vinylidene fluoride-trifluoroethyene) (P(VDF-TrFE)) copolymer thin film having ${\beta}$ phase was prepared by sol-gel method. The electrical properties of the film were studied to evaluate the possibility for appling to a ferroelectric random access memory. In order to characterize its electrical properties, we produced a MFS (metal-ferroelectric-semiconductor) structure by evaporation of Au electrodes. The C-V (capacitance-voltage) measurement revealed that the Au/P(VDF-TrFE)/Si structure with a 4 wt% film had a memory window width of about 0.5V for a bias voltage sweep of 1V.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.150-152
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• 2002

This paper, experiment manufactures device of Metal/Poly-$\gamma-Benzyl\;_D-Glutamate$ Organic Films/Metal structure using PBDG and I-V properties and C-F properties. The I-V characteristic is measured that approve voltage from 0 to +2[V] of device and the distance between electrode is larger, could know that small current flow and thin film could know that had insulation property. C-F characteristic has each other affinity between the polarization amount and frequency. Dielectric constant of MIM device could know by dipole that is voluntary polarization of LB film that polarization is happened. The capacitor properties of a thin film is better as the distance between electrodes is smaller.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.403-404
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• 2007

We prepared the Al doped ZnO (AZO) thin film on polyethersulfon (PES) without any substrate heating by Facing Targets Sputtering (FTS) system. ZnO doped the content of Al 2 wt% was used and the sputtering conditions were gas pressure 1mTorr and input power 100W. The electrical, structural and optical properties of AZO thin films were investigated. To investigate the as-deposited thin film properties, we employed four-point probe, UV/VIS spectrometer, X-ray diffractometer (XRD), scanning electron microscopy (SEM), Hall Effect measurement system and Atomic Force Microscope (AFM).

• Journal of the Semiconductor & Display Technology
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• v.8 no.2
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• pp.49-53
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• 2009

The oxygen barrier films were formed on poly(ethylene terephthalate) (PET) substrate by a sol-gel process using 3-aminoproprytrimethoxysilane (APTMOS). The effects of solvent type, coating times and incorporation of fumed silica on oxygen permeability coefficient were investigated. The APTMOS coating film prepared from methanol as a solvent exhibited higher oxygen barrier properties than that using THF. The oxygen permeability coefficient of coated film with APTMOS/methanol by coating 7 times was measured to be $2.28{\times}10^{-6}$, while that of PET film was $1.16{\times}10^{-4}$ GPU. The addition of fumed silica does not affect the oxygen barrier properties. It may be explained that silica particles disrupt chain packing, which leads to an increase in free volume for permeation.