• Journal of Sensor Science and Technology
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• v.6 no.4
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• pp.252-257
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• 1997

Organic EL devices, which have the sing3e-layer structure of ITO(indium-tin-oxide) /PPV(poly(p-phenylene vinylene))/cathode and the double-layer structure of ITO/PVK (poly(N- vinylcarbazole)) /PPV/cathode, were fabricated and their electro-optical properties were investigated. Experimental results, in single-layer structure, shown that the increment of temperature for thermal conversion of PPV film from $140^{\circ}C$ to $260^{\circ}C$ decreases the maximum luminance from $118.8\;cd/m^{2}$(20V) to $21.14\;cd/m^{2}$(28V) and shift the maximum peak of EL spectrum from 500nm to 580nm. The lower the work function of cathode is, the more the luminance and injection current of device. In double-layer structure, as the concentration of PVK solution decreases from 0.5 wt% to 0.05 wt%, the luminance of device increases from $70.71\;cd/m^{2}$(32V) to $152.7\;cd/m^{2}$(26V).

• Journal of the Microelectronics and Packaging Society
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• v.11 no.3 s.32
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• pp.63-70
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• 2004

The structural, electrical properties of $(Ba, Sr)TiO_3[BSTO]/RuO_2$ thin films were examined by the addition of amorphous BSTO layer between crystlline BSTO film and $RuO_2$ substrate. We prepared BSTO films with double-layered structure, that is, amorphous layers deposited at $60^{\circ}C$ and crystalline films. Crystalline films were prepared at 550 on amorphous BSTO layer. The thickness of the amorphous layers was varied from 0 to 170 nm. During the deposition of crystalline films, the crystallization of the amorphous layers occurred and the structure was changed to circular while crystalline BSTO films showed columnar structure. Due to insufficient annealing effect, amorphous BSTO phase was observed when the thickness of the amorphous layers exceeded 30 nm. Amorphous BSTO layer could also prevent the formation of oxygen deficient region in $RuO_2$ surface. Leakage current of total BSTO films decreased with increasing amorphous layer thickness due to structural modifications. Dielectric constant showed maxi-mum value of 343 when amorphous layer thickness was 30 nm at which the improvement by grain growth and the degradation by amorphous phase were balanced.

• Applied Science and Convergence Technology
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• v.24 no.2
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• pp.33-40
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• 2015

$ZrO_2$ and Al-Zr composite oxide film was prepared by vacuum assisted sol-gel dip coating method and anodizing. $ZrO_2$ films annealed above $400^{\circ}C$ have tetragonal structure. $ZrO_2$ layers inside etch pits were successfully coated from the $ZrO_2$ sol. The double layer structures of samples were obtained after being anodized at 100 V to 600 V. From the TEM images, it was found that the outer layer was $Al_2O_3$, the inner layer was multi-layer of $ZrO_2$, Al-Zr composite oxide and Al hydrate. The capacitance of $ZrO_2$ coated foil exhibited about 28.3% higher than that of non-coating foil after being anodized at 100 V. The high capacitance of $ZrO_2$ coated foils anodized at 100 V can be attributed to the relatively high percentage of inner layer in total thickness. The electrical properties, such as withstanding voltage and leakage current of coated and non-coated Al foils showed similar values. From the results, $ZrO_2$ and Al-Zr composite oxide is promising to be used as the partial dielectric of high voltage capacitor to increase the capacitance.

• Journal of the Korean institute of surface engineering
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• v.45 no.2
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• pp.81-88
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• 2012

Probe tip, which should have not only superior electrical characteristics but also good abrasion resistance for numerous contacts with semiconductor pads to confirm their availability, is essential for MEMS probe card. To obtain good durability of probe tip, it needs thick and crack-free rhodium layer on the tip. However, when the rhodium thickness deposited by electroplating increased, unwanted cracks by high internal stress led to serious problem of MEMS probe tip. This article reported the method of thick Rh deposition with Au buffer layer on the probe tip to overcome the problem of high internal stress and studied mechanical and electrical properties of that. MEMS probe tip with double-Rh layer had good contact resistance and durability during long term touch downs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.230-233
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• 1996

In this paper, We intended to evaluate characteristics of XLPE/EPDM interface which exists in the cable joint. Because the fault was mainly occurred in this interface. We investigated breakdown characteristics of XLPE/EPDM double layered insulator as a funtion of temperature, pressure, annealing time, kinds of jointmaterial. It was shown that breakdown strength of XLPE/EPDM insulators is higher that of XLPE/XLPE or EPDM/EPDM

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.133-136
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• 2000

We investigated the improvement of viewing angle using a patterned double twisted (PDT) vertical-alignment (VA) cell mode on a homeotropic alignment layer. Good voltage-transmittance curves for negative dielectric anisotropic nematic liquid crystal (NLC) using the PDT-VA cell without a negative compensation film were obtained. The viewing angle of the PDT-VA cell without a negative compensation film was wider than that of a conventional VA cell.

• Bulletin of the Korean Chemical Society
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• v.17 no.4
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• pp.349-352
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• 1996

Electrical capacitance at the interface between electrolyte solution and conducting polypyrrole film electrode was measured by a simple electrochemical method. The polymer films were electropolymerized in the presence of perchlorate (PPy-ClO4) or Nafion (PPy-Nafion) anions as the dopant ions. Both polymers exhibited large double layer capacitances which were slightly potential dependent within the potential range where the polymers are conductive. The capacitance increased in proportion to the polymer thickness. The specific capacitance were about 10 Fg-1and 44 F g-1 for PPy-Nafion and PPy-ClO4, respectively.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.491-494
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• 2002

To assess the electrostatic interaction of surfaces at the triple contact line, the electrostatic field is analyzed by using the finite element method. The Helmholtz free energy is used as a functional which should be minimized under an equilibrium condition. The numerical results are compared with the nonlinear analytical solution for a two-dimensional charged interface and linear solution for a wedge shaped geometry, which shows fairly good agreement. The method is applied to the analysis of electrostatic influence on the contact angle on a charged substrate. The excess free energy found to increase drastically as the contact angle approaches to zero. This excess free energy Plays an opposite role to the Primary electrocapillary effect, as the contact angle gets smaller. This enables an alternative explanation for the contact-angle saturation phenomenon occurring in electrical control of surface tension and contact angle.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.1
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• pp.39-46
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• 2000

An analysis of the free vibration for the metal-piezoceramic laminated thin plates is described. The purpose of this study is to develop a equivalent method for the free vibration analysis of metal-piezoce-ramic laminated thin plate which are not sysmmetric about the adhered layer and the piezoelectric effect. In order to confirm the validity of the vibration analysis, double Fourier sine series is used as a modal displacement function of a metal-piezoceramic laminated thin plate and applied to the free vibration analysis of the plate under various boundary conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.04a
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• pp.21-24
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• 2002

In this paper, for the study on the fabrication of YBCO superconductor wire, a double layered YBCO superconductor wire was fabricated by electrophoretic method on metal Ag wire(${\Psi}$0.8 mm). On the basis of previous researches for the fabrication of superconductor wire, the acetone suspension solution with 8 vol.% of 1% PEG(1000) was used and high molecular adhesive was experimentally performed for an improvement of the critical current density of superconductor wire. It was found that the Ag inter-layer deposited on the superconductor wire affect to the state of second YBCO film and its critical current density.