• Nuclear Engineering and Technology
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• v.7 no.2
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• pp.95-106
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• 1975

A comparative study has been carried out on three silicon solar cell samples through their current-voltage (I-V) characteristics and their efficiencies. One sample is an ion-implanted cell made by our laboratory, and the other two samples are the dopant-diffused cells made by a foreign maker. The experiments have shown that both the properties of junction formation and the efficiency of each sample depend highly on the I-V characteristic of each p-n junction. The cause of incomplete properties in the ion-implanted sample has been clarified through this comparative study to be due to the various reasons such as slightly deficient surface impurity concentrations, defects induced by both the radiation and the foreign impurities, and insufficient ohmic contacts at the electrodes. The conversion efficiency of the ion-implanted sample can be figured out to be 4.2% whereas those of the other samples to be 14.3% and 8.3%, respectively.

• Journal of the Korean Magnetics Society
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• v.12 no.6
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• pp.201-205
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• 2002

The tunneling magnetoresistance (TMR) of a ramp-edge type junction has been studied. The samples with a structure of NiO(60)/Co(10)/NiO(60)/Si$_3$N$_4$(2-6)/NiFe(10) (nm) were prepared by the sputtering and etched by the electron cyclotron (ECR) argon ion milling. Nonlinear I-V characteristics was obtained from a ramp-type tunneling junctions having the dominant difference between zero and ＋90 Oe perpendicular to the junction edge line. The voltage dependence of TMR was stable up to a bias volt of $\pm$10 V with a TMR ratio of about -10%, which may be very peculiar magnetic tunneling properties with asymmetric tunneling process between wedge Co pinned layer and NiFe free layer.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.9
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• pp.872-875
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• 2016

In this paper, the turnstile junction-based Ortho-Mode Transducer(OMT) is designed and manufactured. It is usually well-known that turnstile junctions have symmetry structure of waveguide so the higher order modes, which occurs inside the waveguide, can be cancelled. Because of these symmetrical properties, the turnstile junction-based OMTs have merits like high transmission and low return loss characteristic in broadband and two different modes propagate orthogonally in common port resulting in the fully realization of double polarization. The designed OMT has the application of Radar Seeker and operates in W-band(94 GHz), the millimeter wave frequency. The average of return loss value of manufactured OMT is lower than -20 dB and it has bandwidth characteristic of over 500 MHz.

• Korean Journal of Materials Research
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• v.8 no.3
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• pp.263-267
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• 1998

In this study, we have fabricated in-situ multilayer $YBa_2Cu_3O_{7-\delta}$/$SrTiO_{3}$/$YBa_2Cu_3O_{7-\delta}$ ramp edge type junctions by using a metal mask and pulsed laser deposition method and studied the junction properties. The junctions showed RSJ-like I-V characteristics. The normal state junction resistance R, of $18 \omega$ was nearly constant with temperature. The dc-SQUID sensors fabricated with the junctions show a sensitivity that transfer function dV/$d\Phi$)~$22\mu$V/$\Phi_{0}$, indicating that the in-situ ramp edge type junction is potentially useful for sensor application.

• Journal of Magnetics
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• v.7 no.3
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• pp.101-105
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• 2002

MRAM (Magnetoresistive Random Access Memory) is a promising candidate for a universal memory that meets all application needs with non-volatile, fast operational speed, and low power consumption. The simplest architecture of MRAM cell is a series of MTJ (Magnetic Tunnel Junction) as a data storage part and MOS transistor as a data selection part. This paper is for testing the actual electrical parameters to adopt MRAM technology in the semiconductor based memory device. The discussed topics are an actual integration of MRAM core cell and its properties such as electrical tuning of MOS/MTJ for data sensing and control of magnetic switching for data writing. It will be also tested that limits of the MRAM technology for a high density memory.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.951-955
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• 2007

Recently, drywall's demand is increasing by interest about spread of remodeling house and separated wall structure. This research evaluated panel's SRI and found out panel properties using material of small size. Conclusion of this research is as following. First, we confirmed the effectiveness of small-scale material. Measuring results appeared equally about 400 ${\sim}$ 500 Hz that is fc frequency. Second,, it is no big difference in SRI that use CRC or magnesium board that is used for protection of panel surface. Third, it is compared SRI by used junction to make wall that become disjointing assembly. By the result, sealed wall secures resemblant SRI performance almost with normal wall. Therefore, using joint materials and sealing junction became wall that is detached with high SRI.

• Journal of Power Electronics
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• v.13 no.4
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• pp.729-736
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• 2013

Knowledge of a power semiconductor's operating temperature is important in circuit design and converter control. Designing appropriate circuitry that does not affect regular circuit operation during virtual junction temperature measurement at actual operating conditions is a demanding task for engineers. The proposed method enables virtual junction temperature estimation with a dedicated modified gate driver circuit based on real-time measurement of a semiconductor's quasi-threshold voltage. A simulation was conducted before the circuit was designed to verify the concept and to determine the basic properties and potential drawbacks of the proposed method.

• Journal of Magnetics
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• v.16 no.2
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• pp.92-96
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• 2011

This study investigated theoretically the properties of the spin transfer torque acting on a ferromagnet in a ferromagnet-normal metal-antiferromagnet junction. Earlier work showed that the angular dependence of the spin transfer torque can be a wavy-type if the junction satisfies a special symmetry. This paper reports a simple model analysis that allows a derivation of the wavy angular dependence without taking advantage of the symmetry. This result suggests that the wavy angular dependence can appear even when the symmetry is broken. As an illustration, the angular dependence was calculated as a function of the degree of the compensation at the normal metal-antiferromagnet interface. The implications of the result for the current-induced magnetization precession are discussed.

• Proceedings of the KWS Conference
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• 2005.06a
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• pp.48-50
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• 2005

Advanced hard materials based on diamond are in common use. In this study our main goal was employed to analyze, the mechanisms for the rich phases and chromium carbide, interface of a diamond grits brazed to a Ni-based brazing filler metal matrix. When Ni-7Cr-3Fe-3B-4Si (wt. %) was utilized as the brazing alloy, an isothermal holding resulted in the various products(Ni-rich/Cr-rich domains, carbide). According to these results, the chemical compounds and chromium carbides products is considered to play an important role in brazing temperature and time. Especially chromium carbide has an influence on brazing junction properties.

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.39-43
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• 2017

It was confirmed that the silicon thin films fabricated on the p-Si (100) substrates by using DIPAS (DiIsoPropylAminoSilane) and TDMA-Sb (Tris-DiMethylAminoAntimony) sources by RPCVD method were amorphous and n-type silicon. The fabricated amorphous n-type silicon films had electron carrier concentrations and electron mobilities ranged from $6.83{\times}10^{18}cm^{-3}$ to $1.27{\times}10^{19}cm^{-3}$ and from 62 to $89cm^2/V{\cdot}s$, respectively. The ideality factor of the pn junction diode fabricated on the p-Si (100) substrate was about 1.19 and the efficiency of the fabricated pn solar cell was 10.87%.