• Title/Summary/Keyword: depletion layer

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Magnetoresistance Characteristics due to the Schottky Contact of Zinc Tin Oixide Thin Films (ZTO 박막의 쇼키접합에 기인하는 자기저항특성)

  • Li, XiangJiang;Oh, Teresa
    • Journal of the Semiconductor & Display Technology
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    • v.18 no.4
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    • pp.120-123
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    • 2019
  • The effect of surface plasmon on ZTO thin films was investigated. The phenomenon of depletion occurring in the interface of the ZTO thin film created a potential barrier and the dielectric layer of the depletion formed a non-mass particle called plasmon. ZTO thin film represents n-type semiconductor features, and surface current by plasma has been able to obtain the effect of improving electrical efficiency as a result of high current at positive voltage and low current at negative voltage. It can be seen that the reduction of electric charge due to recombination of electronic hole pairs by heat treatment of compound semiconductors induces higher surface current in semiconductor devices.

Oxidation of Hot Pressed Cr2AlC Compounds at 900-1200℃ for Up to 50 Hours in Air (열간 압축법으로 제조된 Cr2AlC 화합물의 900-1200℃, 50시간 동안의 대기중 산화)

  • Lee, Dong-Bok
    • Journal of the Korean institute of surface engineering
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    • v.44 no.4
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    • pp.125-130
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    • 2011
  • $Cr_2AlC$ compounds were synthesized by hot pressing, and oxidized between 900 and $1200^{\circ}C$ in air for up to 50 hours. They oxidized to a thin $Al_2O_3$ layer containing a small amount of $Cr_2O_3$with the liberation of carbon as CO or $CO_2$ gases. The consumption of Al to form the $Al_2O_3$ layer led to the depletion of Al and enrichment of Cr just below the $Al_2O_3$ layer, resulting in the formation of an underlying $Cr_7C_3$ layer. As the oxidation temperature and time increased, the $Cr_7C_3$ oxide layer and the underlying $Cr_7C_3$ layer thickened. The oxidation resistance of $Cr_2AlC$ was generally good due to the formation of the $Al_2O_3$ barrier layer.

Calculation of Forward Voltage Drop of IGBTs (IGBT 순방향 전압강하의 계산)

  • Choe, Byeong-Seong;Jeong, Sang-Gu
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.49 no.3
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    • pp.161-164
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    • 2000
  • A simple methode for calculating the forward voltage drop of IGBTs is presented, on the voltage drops on the p+ body, the reverse biased depletion region between p+body and epi-layer, the epi layer, and the forward biased collector junction. The decrease of the total current density in the epi layer near the p+ body is taken into account. The proposed methode allows a simple but accurate determination of the forward voltage drop in IGBTs, avoiding the complex path taken in the previous model for the forward voltage drops on channel, accumulation region, and epi region. Numerical simulations for 1kV NPT-IGBT with a uniformly doped collector are shown to support the analytical results.

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Dielectric Properties of $SrTiO_3$-based varistors ($SrTiO_3$ 바리스터의 유전특성)

  • Kang, D.H.;Park, I.Y.;Shim, J.G.
    • Proceedings of the KIEE Conference
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    • 2000.07c
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    • pp.1471-1473
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    • 2000
  • In this study capacitance and dielectric loss factor were measured with low-voltage signal and the simulation of equivalent circuits for the data were conducted. As the result it was showed that the equivalent circuit model considered the gram-boundary structure with semiconducting layer, dielectric layer and depletion layer was well approximated with the observed data. Various parameters were determined by a optimum curve-fitting method and could be used to analyze the varistor-voltages and the nonlinear coefficient of varistors. It also seems that the proposed equivalent circuit model will be adopted for other BL type varistors.

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Dielectric Properties and Equivalent Circuit of $Z_nO$ Varistor ($Z_nO$ 바리스터의 유전특성 및 등가회로)

  • Her, J.S.;Park, S.H.;Kang, D.H.
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1418-1420
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    • 2003
  • In this study capacitance and dielectric loss tan${\delta}$were measured with frequency changes for commercial $Z_nO$ varistors with pin-type leads and equivalent circuit simulation was proposed. The leakage inductance in pin leads and the stray caoacitance could be seperated from the dielectric characteristics of $Z_nO$ varistors by the simulation of equivalent circuit. The equivalent circuit model considered semiconduction layer, dielectric layer and depletion layer as the grain boundary structure of varistor is well fitted to the observed data.

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Electrical Characteristics of Super Junction MOSFET According to Trench Etch Angle of P-pillar (P-pillar 식각 각도에 따른 Super Junction MOSFET의 전기적 특성 분석에 관한 연구)

  • Kang, Ey Goo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.27 no.8
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    • pp.497-500
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    • 2014
  • In this paper, we analyze electrical characteristics of n/p-pillar layer according to trench angle which is the most important characteristics of SJ MOSFET and core process. Because research target is 600 V class SJ MOSFET, so conclusively trench angle deduced 89.5 degree to implement the breakdown voltage 750 V with 30% margin rate. we found that on resistance is $22mohm{\cdot}cm^2$ and threshold voltage is 3.5 V. Moreover, depletion layer of electric field distribution also uniformly distributes.

Life Cycle Assessment(LCA) of Rubber Recycling Process in Waste Tire (폐타이어 고무 재활용 공정의 전과정평가 연구)

  • Ahn, Joong Woo;Kim, Jin Kuk
    • Resources Recycling
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    • v.27 no.1
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    • pp.74-83
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    • 2018
  • This study conducted the Life Cycle Assessment(LCA) on waste rubber recycling technology for recovering rubber product from the waste tires. Environmental impacts were assessed for the five categories of impacts: global warming, resource depletion, acidification, eutrophication, photochemical oxide production, and ozone layer depletion. When recycling 1ton of waste tire containing rubber, global warming impact was 1.77E+02 kg $CO_2-eq.$, resource depletion impact was 1.23E+00 kg Sb-eq., acidification impact was 5.92E-01 kg $SO_2-eq.$, eutrophication impact was 1.23E-01 kg $PO{_4}^{3-}-eq.$, photochemical oxide production impact was 3.42E-01 kg $C_2H_4-eq.$, and ozone layer depletion impact was 1.87E-04 kg CFC11-eq. In terms of overall environmental impacts, carbon, softener and electricity the greatest impact, so it is necessary to compare the environmental impacts of the raw materials to replace carbon and softener, and a method to reduce the filler usage in the process is needed. In addition, it is necessary to improve energy efficiency, change to low-energy sources, and apply renewable energy.

Photoeffects at p-GaP Semiconductor Interfaces (p형 GaP 반도체 계면의 광효과)

  • Chun, Jang-Ho
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.10
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    • pp.1528-1534
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    • 1989
  • Photoeffects at the p-GaP semiconductor/CsNO3 electrolyte interface were investigated in terms of their current-voltage characteristics. The photoeffects at the semiconductor-electrolyte interfaces and their photocurrent variations are verified using Ar ion laser and continuous cyclic voltammetric methods. The mechanism of charge transfer at the photogeneration in the depletion layer rather than the photodecomposition of the p-GaP semiconductor electrode surface and/or the water photoelectrolysis. The adsorption of Cs+ ions at the interface is physical adsorption.

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Halon 규제에 대한 대응 방안

  • Kim, Yeong-Bae
    • Fire Protection Technology
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    • s.10
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    • pp.13-18
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    • 1991
  • It seems that the use of one of the major fire-fighting agents-halon-is going to be denied to the fire protection community at the end of the century. It is now being widely accepted that the CFC and halons released into the atomosphere are contributing to both the depletion of the ozone layer green house effect. Therefore, we should research to determine suitable alternative(gaseous) fire extinguishings agents to the halons and improve or develop other extinguishing systems.

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Evaporating heat transfer characteristics of natural gas refrigerants (천연 가스 냉매의 증발 열전달 특성)

  • 김종수
    • The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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    • v.28 no.5
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    • pp.359-367
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    • 1999
  • 최근 10년 동안 우리들은 성층권의 오존층 고갈(depletion of ozone layer), 지구온난화(global warming) 및 산성비(acid rain) 등을 포함하는 지구환경문제를 해결하여야 하는 많은 도전을 받고 있다. 몬트리올조약과 Montreal Protocol)이 수정되어 특정 CFC계 냉매들의 생산삭감계획이 앞당겨짐에 따라 우리들은 조속히 이들 문제를 해결해야될 심각한 국면에 직면하고 있다.

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