• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.51-51
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• 2010

We have proposed a new configuration for the improvement of neutron yield without the application of external ion sources in an inertial electrostatic confinement (IEC) device. The application of a double grid cathode to the IEC device is expected to generate a higher ion current than a single grid cathode. This paper verifies the effect of the double grid cathode by both fluid and particle simulation. Through the fluid simulation the optimal shape and applied voltage of the double grid cathode is determined, and through the particle simulation the usefulness of that is confirmed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.9
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• pp.724-729
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• 2010

We have proposed a new configuration on the cathode structure to improve a neutron yield without the application of external ion sources in an inertial electrostatic confinement (IEC) device. A neutron yield in the IEC device is closely related to the potential well structure generated inside the cathode and is proportional to the ion current. Therefore, the application of a double grid cathode structure to the IEC device is expected to produce a higher ion current and neutron yield than at a single grid cathode due to a high electric field strength generated around the cathode. These possibilities were verified as compared with the ion current calculated from both shape of the single and double grid cathode. Additionally from the results of ion's lives and trajectories examined at various outer cathode voltages and grid cathode configurations by using particle simulations, the validity of the double grid cathode was confirmed.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.56.1-56.1
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• 2009

The intermediate operating temperature of solid oxide fuel cells (IT-SOFCs) have achieved considerable importance in the area of power fabrication. This is because to improve materials compatibility, their long-term stability and cost saving potential. However, to conserve rational cell performance at reduced-temperature regime, cathode performance should be obtained without negotiating the internal resistance and the electrode kinetics of the cell. Recently, double perovskite structure cathodes have been studied with great attention as a potential material for IT-SOFCs. In this study, double-perovskite structured cathodes of $GdBaCoCuO_{5+\delta}$, $GdBaCo_{2/3}Cu_{2/3}Fe_{2/3}O_{5+\delta}$ compositions and $(1-x)GdBaCo_2O_{5+\delta}+xCe_{0.9}Gd_{0.1}O_{1.95}$ (x = 10, 20, 30 and 40 wt.%) composites were evaluated as the cathode for intermediate temperature solid oxide fuel cells(IT-SOFCs). Electrical conductivity of the cathodes were measured by DC 4-probe method, and the thermal expansion coefficient of each sample was measured up to $900^{\circ}C$ by a dilatometer study. Area specific resistances(ASR) of the $GdBaCo_{2/3}Cu_{2/3}Fe_{2/3}O_{5+\delta}$ cathode and 70 wt.% $GdBaCo_2O5+\delta$ + 30wt.% Ce0.9Gd0.1O1.95 composite cathode on CGO electrolyte substrate were analyzed using AC 3-probe impedance study. The obtained results demonstrate that double perovskite-based compositions are promising cathode materials for IT-SOFCs.

• Transactions on Electrical and Electronic Materials
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• v.15 no.1
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• pp.45-48
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• 2014

We have investigated the effects of an Ag capping layer on the emission characteristics of transparent organic light-emitting devices with Ca/Ag double-layer cathodes. The thickness of the Ag layer was varied from 10 to 30 nm, whereas the Ca was fixed to be a 10 nm in the Ca/Ag structure. The luminance and current efficiency on the cathode and anode sides are significantly dependent on the Ag thickness. For example, the current efficiency on the anode side increases from 8.4 to 11.7 cd/A, whereas, on the cathode side, it decreases from 3.2 to 0.2 cd/A as the Ag thickness increases from 10 to 30 nm. These changes in emission characteristics were investigated by measuring electroluminescence, transmission, and reflection spectra.

• Journal of Information Display
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• v.7 no.3
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• pp.23-26
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• 2006

We fabricated top emission organic light emitting diode (TEOLED) with transparent metal cathode Barium and Silver bilayer. Very thin Ba/Ag bilayer was deposited on the organic layer by thermal evaporation. This cathode showed high transmittance over 70% in visible range, and the device with a Ba-Ag has a low turn on voltage and good electrical properties.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.990-993
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• 2006

We fabricated top emission organic light emitting diode (TEOLED) with transparent metal cathode Barium and Silver bilayer. Very thin Ba/Ag bilayer was deposited on the organic layer by thermal evaporation. This cathode shows high transmittance over 70% in visible range. And the device with a Ba-Ag has a low turn on voltage and good electrical properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.457-458
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• 2006

Transparent metal cathodes using Ca/Ag, Ba/Ag double layers have been fabricated to investigate its optical transmission. The transmission spectra show that Ca/Ag and Ba/Ag double layers result in higher transmittance compared to Ag single layer. The Ba/Ag double layer shows over 80% transmittance at 400 nm and 70% at 700 nm. The electroluminescence efficiency of fluorescent TEOLED using Ba/Ag transparent metal cathode was 10 ~ 15 cd/A.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.345-346
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• 2008

We have studied an emission spectra of top-emssion organic light-emitting diodes(TEOLED) due to a change of cathode and organic layer thickness. Device structure is Al(100nm)/TPD(xnm)/$Alq_3$(ynm)/LiF(0.5nm)/cathode. And two different types of cathode were used; one is LiF(0.5nm)/Al(25nm) and the other is LiF(0.5nm)/Al(2nm)/Ag(30nm). While a thickness of hole-transport layer of TPD was varied from 35 to 65nm, an emissive layer thickness of $Alq_3$ was varied from 50 to 100nm for two devices. A ratio of those two layer was kept to be about 2:3. Al and Al/Ag double layer cathode devices show that the emission spectra were changed from 490nm to 560nm and from 490nm to 560nm, respectively, when the total organic layer increase. Full width at half maximum was changed from 67nm to 49nm and from 90nm to 35nm as the organic layer thickness increases. All devices show that view angle dependent emission spectra show a blue shift. Blue shift is strong when the organic layer thickness is more than 140nm. Devece with Al/Ag double layer cathode is more vivid.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1071-1074
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• 2006

Ca/Ag double layer which is fabricated by thermal evaporation exists as the double layer of (Ca+O)/(Ag+Ca). In Ca layer, are crystalline Ca(OH)2 and amorphous Ca and in Ag layer, are crystalline Ag and amorphous Ca. And for the certain thickness of Ag, in the Ca/Ag double layer, the thicker Ca is, the higher transmittance is.

• Journal of the Korean Electrochemical Society
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• v.25 no.1
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• pp.32-41
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• 2022

Various steps in the electrode production process, such as slurry mixing, slurry coating, drying, and calendaring, directly affect the quality and, consequently, mechanical properties and electrochemical performance of electrodes. Herein, a new method of slurry coating is developed: Double-coated electrode. Contrary to single-coated electrode, the cathode is prepared by double coating, wherein each coat is of half the total loading mass of the single-coated electrode. Each coat is dried and calendared. It is found that the double-coated electrode possesses more uniform pore distribution and higher electrode density and allows lesser extent of particle segregation than the single-coated electrode. Consequently, the double-coated electrode exhibits higher adhesion strength (74.7 N m^-1) than the single-coated electrode (57.8 N m^-1). Moreover, the double-coated electrode exhibits lower electric resistance (0.152 Ω cm^-2) than the single-coated electrode (0.177 Ω cm^-2). Compared to the single-coated electrode, the double-coated electrode displays higher electrochemical performance by exhibiting better rate capability, especially at higher C rates, and higher long-term cycling performance. Despite its simplicity, the proposed method allows effective electrode preparation by facilitating high electrochemical performance and is applicable for the large-scale production of high-energy-density electrodes.