• 제목/요약/키워드: contact barrier

검색결과 304건 처리시간 0.03초

LiF 음극 버퍼층을 사용한 폴리머의 효율 향상에 관한 임피던스 분석 (Impedance spectroscopy analysis of polymer light emitting diodes with the LiF buffer layer at the cathode/organic interface)

  • 김현민;장경수;이준신;손선영;박근희;정동근
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.277-278
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    • 2005
  • Admittance Spectroscopic analysis was applied to study the effect of LiF buffer layer and to model the equivalent circuit for poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV)-based polymer light emitting diodes (PLEDs) with the LiF cathode buffer layer. The single layer device with ITO/MEH-PPV/Al structure can be modeled as a simple parallel combination of resistor and capacitor. Insertion of a LiF layer at the Al/MEH-PPV interface shifts the highest occupied molecular orbital level and the vacuum level of the MEH-PPV layer as a result the barrier height for electron injection at the Al/MEH-PPV interface is reduced. The admittance spectroscopy measurement of the devices with the LiF cathode buffer layer shows reduction in contact resistance ($R_c$), parallel resistance ($R_p$) and increment in parallel capacitance ($C_p$).

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Numerical modeling of two-dimensional simulation of groundwater protection from lead using different sorbents in permeable barriers

  • Masood, Zehraa B.;Ali, Ziad Tark Abd
    • Environmental Engineering Research
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    • 제25권4호
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    • pp.605-613
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    • 2020
  • This study is to investigate the possibility of using activated carbon prepared from Iraqi date-pits (ADP) which are produced from palm trees (Phoenix dactylifera L.) as low-cost reactive material in the permeable reactive barrier (PRB) for treating lead (Pb+2) from the contaminated groundwater, and then compare the results experimentally with other common reactive materials such as commercial activated carbon (CAC), zeolite pellets (ZP). Factors influencing sorption such as contact time, initial pH of the solution, sorbent dosage, agitation speed, and initial lead concentration has been studied. Two isotherm models were used for the description of sorption data (Langmuir and Freundlich). The maximum lead sorption capacities were measured for ADP, CAC, and ZP and were found to be 24.5, 12.125, and 4.45 mg/g, respectively. The kinetic data were analyzed using various kinetic models particularly pseudo-first-order, pseudo-second-order, and intraparticle diffusion. COMSOL Multiphysics 3.5a depend on finite element procedure was applied to formulate transmit of lead (Pb+2) in the two-dimensional numerical (2D) model under an equilibrium condition. The numerical solution shows that the contaminant plume is hindered by PRB.

나노 사이즈의 Ag dot을 성막한 ITO 애노드의 오존처리에 의한 유기발광소자의 홀 주입 특성 향상 (Enhancement of Hole Injection in Organic Light Emitting Device by using Ozone Treated Ag Nanodots Dispersed on ITO Anode)

  • 문종민;배정혁;정순욱;이민수;김한기
    • 한국전기전자재료학회논문지
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    • 제19권11호
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    • pp.1037-1043
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    • 2006
  • We report the enhancement of hole injection using ozone-treated Ag nanodots dispersed on indium tin oxide anode in $Ir(ppy)_3-doped$ phosphorescent OLED. Phosphorescent OLED fabricated on Ag nanodots dispersed ITO anode showed a lower turn on voltage and higher luminescence than those of OLEDS prepared commercial ITO anode. Synchrotron x-ray scattering examination results showed that the Ag nanodots dispersed on ITO anode is amorphous structure due to low deposition temperature. It was thought that decrease of the energy barrier height as Ag nanodots changed to $AgO_x$ nanodots by surface treatment using ozone for 10 min led to enhancement of hole injection in phosphorescent OLED. Futhermore, efficient hole injection can be explained by increase of contact region between anode material and organic material through introduction of $Ag_2O$ nanodots.

반사형 InGaAs MQW SEED 소자의 제작 및 특성 (Fabrication and Characteristics of Reflection Type InGaAs MQW SEED)

  • 김성우;박성수;박종철;김택승;권오대;강봉구
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 C
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    • pp.1216-1219
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    • 1994
  • A reflection type SEED from LP-MOCVD grown InGaAs/GaAs ESQW structures, with 5% In fraction, has been fabricated and its basic characteristics were investigated. Its intrinsic region consists of 50 pairs of alternating $100{\AA}$ $In_{0.05}Ga_{0.95}As$ barrier and $100{\AA}$ GaAs layers. And a multilayer reflector stack of $Al_{0.12}Ga_{0.88}As(641{\AA})-/AlAs(774{\AA})$ was vertically integrated below the p-i-n structures. The device processing includes the mesa etching, insulator deposition, indium metallization, and thermal alloy for Ohmic contact. Photocurrent spectrum measurement showed the exciton absorption peak at 905nm and availability as a optical switching device. This device showed a contrast ratio of 2:1 by the reflectance spectrum measurement.

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토치형 상압 플라즈마의 방전특성과 미생물의 국부 살균효과 (Discharge Properties of Torch-Type Atmospheric Pressure Plasma and Its Local Disinfection of Microorganism)

  • 손향호;이원규
    • Korean Chemical Engineering Research
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    • 제49권6호
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    • pp.835-839
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    • 2011
  • 토치형 상압 플라즈마 반응기를 통한 방전 및 플라즈마 flame에 대한 분석과 발생된 플라즈마 현상을 이용하여 E. coli에 대한 살균효과를 측정하였다. 상압 플라즈마 반응기를 통해 나오는 플라즈마 flame의 길이는 입력전압, 반응기의 유량 그리고 아르곤/산소 혼합기체에서의 산소비율에 영향을 크게 받았다. 플라즈마 flame에 의한 가열효과는 10분 조사 후에도 $43^{\circ}C$ 미만으로 저온처리가 가능했다. E. coli에 대한 살균처리에서 입력전압의 증가, 아르곤/산소 혼합기체에서의 산소비율 증가 그리고 플라즈마 flame에 대한 노출시간의 증가에 따라 전체적인 살균효과를 향상되었다. 플라즈마 처리 시에 오존농도가 높은 공정조건에서 플라즈마 flame의 직접적인 접촉시간을 증가시키면 살균효과를 극대화할 수 있다.

강유전체층을 갖는 선대선 방편 플라즈마장치의 코로나 방전 및 오존발생 특성 (Corona Discharge and Ozone Generation Characteristics of a Wire-to-Wire Plasma Reactor with a Ferroelectric Pellet Layer)

  • 문재덕;신정민;한상옥
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제53권7호
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    • pp.377-381
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    • 2004
  • A discharge plasma reactor using a ferroelectric pellet packed bed is now used as a removal means of pollutant gases, such as NOx, SOx and VOCs. When an ac voltage is applied to this plasma reactor, then the pellets are polarized, and great electric fields are formed at each top and bottom contact points of the ferroelectric pellets. Thus the points of each pellet become covered with intense corona discharges, where an electrophysicochemical reaction is taking place strongly However these strong discharges also elevate the temperature of the pellets greatly and concurrently decrease the output ozone generation, as a result, the overall removal efficiency of gas becomes decreased greatly A new configuration of discharge plasma reactor using a ferroelectric pellet layer and a wire-to-wire electrode has been proposed and investigated experimentally. It is found that an intensive microdischarge is taking place on the surface of ac corona-charged ferroelectric pellet layer of the proposed reactor, which concurrently enhances the efficiency of plasma generation greatly And, this type of configuration of plasma reactor utilizing a wire-to-wire electrode and a ferroelectric pellet layer could be used as one of effective plasma reactors to remove pollutant gas.

죠셉슨 소자구현을 위한 YBCO다층 박막 제작 및 특성 (Fabrication and Charactreization of YBCO Multi-layer Thin Films for Josephson device)

  • 이현수;박재윤;박상현;이동훈;박홍재;김영주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2002년도 학술대회 논문집 전문대학교육위원
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    • pp.49-51
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    • 2002
  • In this thesis, Josephson junction using high-Tc superconducting multi-layer thin film has been fabricated by on-axis RF magnetron sputtering method. And, the characterizations were performed by X-ray diffraction, SEM and the measuring system of critical current density. The physical properties of multi-layer superconducting thin films were also analyzed with the measured results. To fabricate the multi-layer superconducting thin films, the optimum partial pressure of Argon and Oxgen and the temperature of substrate were measured. Also, YBaCuO thin film was grown on MgO and $SrTiO_3$ substrates by rf-sputtering and LGO thin film of 30 A was epitaxially grown on the YBaCuO thin film as a josephson junction with the same condition. The schottky barrier at the contact surface between YBaCuO/LGO and YBaCuO/Au and the energy gap of 0.5 ${\sim}$ 0.6 mV in Nb were observed from the dI/dV-V of YBaCuO/LGO/Au/Nb and YBaCuO/Au/Nb.

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Polymerized Organic Thin Films and Comparison on their Physical and Electrochemical Properties

  • Cho, S.H.;You, Y.J.;Kim, J.G.;Boo, J.H.
    • 한국표면공학회지
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    • 제36권1호
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    • pp.9-13
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    • 2003
  • Plasma polymerized organic thin films were deposited on Si(100), glass and metal substrates at $25∼100 ^{\circ}C$ using thiophene and toluene precursors by PECVD method. In order to compare physical and electrochemical properties of the as-grown thin films, the effects of the RF plasma power in the range of 30∼100 W and deposition temperature on both corrosion protection efficiency and physical properties were studied. We found that the corrosion protection efficiency ($P_{k}$), which is one of the important factors for corrosion protection in the interlayer dielectrics of microelectronic devices application, was increased with increasing RF power. The highest $P_{k}$ value of plasma polymerized toluene film (85.27% at 70 W) was higher than that of the plasma polymerized thiophene film (65.17% at 100 W), indicating inhibition of oxygen reduction. The densely packed and tightly interconnected toluene film could act as an efficient barrier layer to the diffusion of molecular oxygen. The result of contact angle measurement showed that the plasma polymerized toluene films have more hydrophobic surface than those of the plasma polymerized thiophene films.

ZnO 나노선 FET에서의 접촉 에너지 장벽의 전기적 특성 연구 (Electrical properties and contact energy barrier of ZnO nanowire field effect transistor)

  • 김강현;임찬영;김혜영;김규태;강해용;이종수;강원
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.13-14
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    • 2005
  • ZnO 단일 나노선 field effect transistor (FET) 소자의 2단자 전류-전압 특성을 조사해 보면 n-type 반도체 특성이 나타남을 알 수 있다. 그러나 2단자로 측정 할 경우 반도체 나노선과 금속 전극사이에 존재하는 접촉저항의 영향이 필연적으로 포함된다. 따라서 측정한 결과가 나노선에 의해서 나타나는 고유한 특성인지 접촉저항의 원인이 되는 에너지 장벽의 성질인지 명확히 밝힐 필요가 있다. 그래서 이번 연구에서는 4단자 측정방법을 이용하여 접촉저항 성분을 배제한 소자의 고유한 성질을 밝혀낼 뿐만 아니라, 이것을 2단자의 결과와 비교함으로써 접촉점에서 나타나는 에너지 장벽의 특징도 파악해 낼 수 있었다. 실험에서 사용된 ZnO FET 소자의 경우, 접촉점에서 생기는 에너지 장벽을 터널링을 통해 극복하는 것으로 분석되었고 이는 온도 변화에 따른 4 단자 및 2 단자 전류-전압 측정을 통해 확인될 수 있었다.

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A Case of Acral Lick Dermatitis in a Dog with Multiple Lesions

  • Kim, Jihee;Kim, Yoonji;Kim, Soomin;Kim, Hyeon-Jin;Lee, Ji-Hye;Kim, Ha-Jung
    • 한국임상수의학회지
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    • 제38권4호
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    • pp.194-198
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    • 2021
  • A 7-year-old intact male Maltese dog was presented with firm, raised, erythematous, alopecic, and pruritic skin lesions on the right dorsal distal metatarsal region and the tail. The skin lesion started a year ago with a crust-like lesion on the right dorsal distal metatarsal region which gradually swelled as the patient continued to lick and chew without healing. Recently, similar lesions occurred on the tail. Based on the licking history and ruling out other diseases through skin examination, acral lick dermatitis (ALD) was diagnosed. Treatment included antidepressants, preventive antibiotics, topical corticosteroid, and wearing Elizabethan collar as a physical barrier. After three weeks, the lesion on the hind limb healed entirely. However, the tail lesion recurred as it was able to lick the tail again with a type of an E-collar. This case shows that it is essential to block the contact lesion and provide medical treatment until the lesion has been completely resolved for successful management of ALD.