• Transactions on Electrical and Electronic Materials
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• v.10 no.4
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• pp.143-145
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• 2009

The electrical and photovoltaic properties of single junction silicon quantum dot solar cells are investigated. A prototype solar cell with an effective area of 4.7 $mm^2$ showed an open circuit voltage of 394 mV and short circuit current density of 0.062 $mA/cm^2$. A diode model with series and shunt resistances has been applied to characterize the dark current-voltage data. The photocurrent of the quantum-dot solar cell was found to be strongly dependent on the applied voltage bias, which can be understood by consideration of the conduction mechanism of the activated carriers in the quantum dot imbedded material.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.296-298
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• 1991

When insulating oil was flowed through a pipe, the electrostatic charge in the oil was increased using inflammability oil, an electrostatic phnomena which may cause significantly problems as explosion must be circumvented by some methods. In this paper, Streaming insulating oil electrificated by streaming electrification of electrification pipe and standing insulating oil were affected under the high field strength, temperature of insulating oil, and concentration of surfactant. The electrical conduction was compared and analysed by these influence.

• Journal of the Korean Ceramic Society
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• v.28 no.6
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• pp.437-442
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• 1991

Temperature and atmosphere dependence of electrical conduction of the metal Cu, Ag, Au films, vaccum evaporated on glass, was investigated. The structural changes of the metal films were examined by SEM and high temperature XRD. The electrical resistance slightly increased with initial temperature increase up to the inflection point and decreased to minimum value, after this rapidly increased with further temperature increased below minimum. These phenomena were caused by the thermally induced film failure as a result of the mass transport. The temperature for the film failure increased in the order of O2, Air, Vacuum, N2, Ar in Cu, Ag films and Air, Vacuum, N2, Ar in Au film. The increase of resistance at the lower temperature range was attributed to the lattice distortion by disordered crystal structure, while the decreasing resistance was attributed to the removal of structural defects and film densification.

• The Transactions of the Korean Institute of Power Electronics
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• v.23 no.4
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• pp.294-297
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• 2018

This paper analyzes the losses of the switching device for a full bridge inverter connected to the grid. As the development of power conversion system, losses are dominant factors in judging the efficiency of a system. The losses of a switching device can be divided into switching loss and conduction loss, both of which can be estimated by analyzing periodic switching waveform. The switching loss is generated when the switch is turned on and off, while the conduction loss is generated when the switch is turned on. The estimated losses of the MOSFET switch are compared with the simulation results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.10
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• pp.1786-1790
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• 2007

The $(SrCa)TiO_3(SCT)$ thin films are deposited on Pt-coated electrode ($Pt/TiN/SiO_2/Si$) using RF sputtering method at various deposition temperature. The dielectric constant of SCT thin films were increased with the increase of deposition temperature, and changed almost linearly in temperature ranges of $-80{\sim}+90[^{\circ}C]$. Also, SCT thin films was observed the phenomena of dielectric relaxation with the increase of frequency, and the relaxation frequency was observed above 200[kHz]. V-I characteristics of SCT thin films show the increasing leakage current with the increases of deposition temperature. The conduction mechanism of the SCT thin films observed in the temperature range of $25{\sim}100[^{\circ}C]$ can be divided into three characteristic regions with different mechanism by the increasing current. The region 1 below 0.8[MV/cm] shows the ohmic conduction. The region 2 can be explained by the Child's law, and the region 3 is dominated by the tunneling effect.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.67-70
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• 1995

Amorpous As$\sub$10/Ge$\sub$15/Te$\sub$75/ device shows the memory switching characterisite under d.c. bias. In bulk material, a-As$\sub$10/Ge/sub15/Te$\sub$75/s switching voltage range is above 100 volts. Our purposes in this gaudy are decreasing a switching threshold voltage, finding the properties of d.c., a.c. conduction, and the characterisitics of switching threshold voltage fur a-As$\sub$10/Ge$\sub$15/Te$\sub$75/. As the results, the d.c.and a.c. conductivities increase with temperature. From the data of conductivity, various electrical and physical properties are obtained experimentally. The switching threshold voltages decrease with increasing annealing temperature and time, but increase with increasing film thickness and distance of electrode for d.c. bias.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.74-77
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• 1997

We have examined conduction properties and electrochemical properties of MCMB 6-28 and MPCF 3000. As results, electrical conductivity of carbon decreased with increasing the number of intercalated lithium ion. MCMB and MPCF showed reversible redox reaction, and the potentials of the oxidized and reduced peaks were 0.3V and 0V, respectively. First discharge capacity of MCMB was 190㎃f/g and that of MPCF was 220㎃h/g. MPCF has good properties for lithium secondary battery.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.263-266
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• 1998

ZnO varistors have an excellent non-linearity and a large surge-energy absorption capability. For these reasons, the ZnO varistors are widely used to protect electrical/electronic circuits from an abnormal surge and/or noise signal. In order to obtain the low-voltage varistor with randomly distributed large seed grain within bulk, the ZnO varistors are made by a new three-composition seed grain method. And a conduction mechanism of varistors, which was observed in the temperature range of 30 ∼ 120$^{\circ}C$ and at the current range of 10$\^$-8/∼10$^2$ A/cm$^2$, was classified by the three regions of different mechanism when the current was increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.253-253
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• 2010

The Polymer/MWCNT composite films were fabricated by air-spray method under the 2 kg/$cm^2$ pressure using the multi-walled CNTs solution and the polymer on a $50{\mu}m$ kepton film substrates. We obtained the composite films which were sprayed with the MWCNT dispersion. In order to analysis the microstructure for the fabricated Polymer/MWCNT film, we used the X-ray diffraction (XRD) and SEM.

• Journal of Power Electronics
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• v.16 no.5
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• pp.1861-1868
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• 2016

In this paper, a three-phase AC-DC high step-up converter is developed for application to microscale wind-power generation systems. Such an AC-DC boost converter prossessess the property of the single-switch high step-up DC-DC structure. For power factor correction, the advanced half-stage converter is operated under the discontinuous conduction mode (DCM). Simulatanously, to achieve a high step-up voltage gain, the back half-stage functions in the continuous conduction mode (CCM). A high voltage gain can be obtained by use of an output-capacitor mass and a coupled inductor. Compared to the output voltage, the voltage stress is decreased on the switch. To lessen the conducting losses, a low rated voltage and small conductive resistance MOSFETs are adopted. In addition, the coupled inductor retrieves the leakage-inductor energy. The operation principle and steady-state behavior are analyzed, and a prototype hardware circuit is realized to verify the performance of the proposed converter.