• Title/Summary/Keyword: Junction

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STUDIES OF CELL COMMUNICATION BY USING GAP JUNCTION CHANNELS RECONSTITUTE IN UNILAMELLAR LIPID VESICLES

  • Joe, Cheol-O
    • Proceedings of the Korean Biophysical Society Conference
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    • 1996.07a
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    • pp.6-6
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    • 1996
  • Gap junction channels were reconstituted into unilamellar liposomes using immunoaffinity purified connexin 32 gap junction protein from rat liver. Vesicles containing open channels and close channels were separated by means of iso-osmolar sucros density gradient sedimentation. The open channels formed in lipid vesicles were permeable to a fluorescent dye molecule, lucifer yellow of which the hydrodynamic size is similar to pore size of gap junctions in vivo. (omitted)

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Macro-Model of Magnetic Tunnel Junction for STT-MRAM including Dynamic Behavior

  • Kim, Kyungmin;Yoo, Changsik
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.6
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    • pp.728-732
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    • 2014
  • Macro-model of magnetic tunnel junction (MTJ) for spin transfer torque magnetic random access memory (STT-MRAM) has been developed. The macro-model can describe the dynamic behavior such as the state change of MTJ as a function of the pulse width of driving current and voltage. The statistical behavior has been included in the model to represent the variation of the MTJ characteristic due to process variation. The macro-model has been developed in Verilog-A.

Super Junction LDMOS with N-Buffer Layer (N 버퍽층을 갖는 수퍼접합 LDMOS)

  • Park Il-Yong
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.55 no.2
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    • pp.72-75
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    • 2006
  • A CMOS compatible Super Junction LDMOS (SJ-LDMOS) structure, which reduces substrate-assisted depletion effects, is reported. The proposed structure uses a N-buffer layer between the pillars and P-substrate to achieve global charge balance between the pillars, the N-buffer layer and the P-substrate. The new structure features high breakdown voltage, low on-resistance, and reduced sensitivity to doping imbalance in the pillars.

Effect of barrier materials on the properties of magnetic tunnel junctions

  • 박병국;임우창;배지영;이택동
    • Proceedings of the Korean Magnestics Society Conference
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    • 2002.12a
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    • pp.66-67
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    • 2002
  • Magnetic tunnel junction에서는 spin의 tunneling이 가장 기본적인 현상이기 때문에 tunnel junction의 특성은 tunnel barrier의 성질에 크게 의존한다. Tunnel barrier로는 지금까지 $Al_2$O$_3$가 주로 사용되고 있다. 하지만 $Al_2$O$_3$의 경우는 barrier height가 2-3 eV로 높기 때문에 저 저항의 tunnel junction을 형성하기 위해서는 Al의 두께가 1nm 이하로 낮아져야 한다. 따라서 이를 극복하기 위해서 $Al_2$O$_3$ 보다 낮은 barrier height를 갖는 절연막을 tunnel barrier로 사용하고자 하는 연구가 많이 진행되고 있다 (예를 들면 TaOx [1], ZrOx [2], GaOx [3], and HfOx [4]). (중략)

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Magnetic tunnel junctions with thin free layer

  • 임우창;박병국;배지영;이택동
    • Proceedings of the Korean Magnestics Society Conference
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    • 2002.12a
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    • pp.68-69
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    • 2002
  • Magnetic tunnel junctions은 최근 자기저항용 재료나 MRAM용 소자로 사용하기 위한 연구가 활발하게 진행되고 있다. Magnetic tunnel junction을 저자계, 저전력용 소자로 사용되기 위해서는, 작은 switching field 값과 uniform한 switching field 분포를 가져야 한다. Micromagnetic simulation을 통하여 free layer의 두께와 포화 자화 값이 감소함에 따라서 switching field가 감소함을 알 수 있었다. 본 연구에서는 얇은 free layer를 사용하여 magnetic tunnel junction을 제조하고, 얇은 free layer가 자기저항에 미치는 영향에 대하여 알아보았다. (중략)

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Optimized doping density and doping profile of pn junction for using high power device

  • Jang, Geon-Tae
    • Proceeding of EDISON Challenge
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    • 2016.03a
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    • pp.347-349
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    • 2016
  • 본 논문에서는 dopant density에 의존적인 pn junction의 breakdown 특성을 향상시키기 위하여, doping density와 doping profile에 대하여 분석했다. Doping density와 doping profile은 역방향 junction breakdown voltage를 결정하는 중요한 요소인 공핍영역의 두께와 공핍영역 내에 인가되는 electric field를 결정한다. Uniform doping profile과 Gaussian doping profile을 비교했고, 고전압 환경에서 사용할 수 있는 소자를 제작하는데 더욱 적절한 doping profile과 doping 농도에 대해 기술했다.

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Low Temperature Properties of Exchange-biased Magnetic Tunnel Junction

  • Lee, K. I.;J. G. Ha;S. Y. Bae;K. H. Shin
    • Proceedings of the Korean Magnestics Society Conference
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    • 2000.09a
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    • pp.325-326
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    • 2000
  • Low temperature diagnosis was performed as a probe for the integrity of MTJ(Magnetic tunnel junction) process which is optimised for the given plasma oxidation condition. TMR ratio increased slowly with decreasing temperature than that expected from spin wave exitation theory〔1〕. Junction resistance (RJ) does not follow T$\^$-$\frac{1}{2}$/ law below 200 K, indicating another conduction path besides spin polarized tunneling is involved at low temperature. Temperature dependence of conductance dip and bias dependence of TMR with temperature are discussed, from which the quality of tunnel barrier and its formation process can be inferred.

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Effect of the Epoxy Mold on the Thermal Dissipation Behavior of LED Package (LED 패키지에서 에폭시 몰드가 방열특성에 미치는 영향)

  • Bang, Young-Tae;Moon, Cheol-Hee
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.2
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    • pp.1-7
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    • 2012
  • LED package with 4[mm]-height mold was manufactured and the surface temperature was measured directly using both thermocouple and thermal infrared (IR) camera. FVM simulation was conducted to estimate the surface temperature of the same LED package under the same condition, by which the accuracy of the simulation was secured. Then, the effects of the height and thermal conductivity of the mold on the junction temperature of the LED package were investigated by FVM simulation. The results showed that the junction temperature decreased by 10[$^{\circ}C$] when the mold height was 3~5[mm], but the thermal conductivity of the mold didn't affect the junction temperature significantly.

Effects of optical properties in hydrogenated amorphous silicon germanium alloy solar cells (a-SiGe solar cell의 광학적 특성)

  • Baek, Seungjo;Park, Taejin;Kim, Beomjoon
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.67.1-67.1
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    • 2010
  • Triple junction solar cell을 위한 a-SiGe middle cell의 조건별 광학적 특성에 관한 연구를 실시하였다. a-SiGe I층은 GeH4 유량, 압력, H2 dilution ratio를 변화시켜 제조하였으며 전기적, 광학적 특성을 비교하여 최종적으로 선택된 조건을 triple junction solar cell에 적용하였다. a-SiGe I층은 Ge contents가 증가함에 따라 band gap은 감소하고 45% 이상의 조건에서는 700nm 전후 파장의 투과율이 감소하며, 압력이 감소함에 따라 band gap은 소폭 감소하나 700nm 전후 파장의 투과율은 증가하였다. 그리고 H2 ratio가 증가함에 따라 band gap은 소폭 감소하나 투과율에는 큰 변화가 없었다. 상기 결과를 바탕으로 최종적으로 선택된 조건에서 triple-junction solar cell을 제작하여 평가한 결과 초기 변환효율 9%의 결과를 얻었다.

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Study of the Energy Level Alignment of Organic Materials' Planar Junction Prepared by Electrospray Vacuum Deposition

  • Kim, Ji-Hun;Hong, Jong-Am;Seo, Jae-Won;Gwon, Dae-Gyeon;Maeng, Min-Jae;Park, Yong-Seop
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.235-235
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    • 2012
  • We investigated the energy levels of valence region at the planar junction of poly (3-hexylthiophene) (P3HT) and C61-butyric acid methylester (PCBM) using ultraviolet photoemission spectroscopy (UPS) with ultra high vacuum. These are the most widely used materials for bulk heterojunction (BHJ) organic solar cells due to their high efficiency. In order to make the planar junction, we carried out the electrospray vacuum deposition (EVD) of PCBM onto spin-coated P3HT in high vacuum conditions (${\sim}10^{-5}-10^{-6}$). The planar junction interface exhibited 0.71 eV for the offset between P3HT HOMO and PCBM LUMO, which is different from the gap (0.85 eV) of individual values and is closer to the open circuit voltage of solar cells fabricated with the same material combination.

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