• 제목/요약/키워드: Buffer material

검색결과 536건 처리시간 0.039초

RF 플라즈마를 이용한 유기 EL 소자의 전극형성에 관한 연구 (A Study on the Electrode formation of an Organic EL Devices using the RF Plasma)

  • 이은학
    • 한국전기전자재료학회논문지
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    • 제17권2호
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    • pp.228-235
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    • 2004
  • In this thesis, it is designed efficient electrode formation on the organic luminescent device. ITO electrode is treated with $O_2$plasma. In order to inject hole efficiently, there is proposed the shape of anode that inserted plasma polymerized films as buffer layer between anode and organic layer using thiophene monomer. It is realized efficiently electron injection to aluminum due to introduce the quantum well in cathode. In the case of device inserted the buffer layer by using the plasma poiymerization after $O_2$plasma processing for ITO transparent electrode, since it forms the stable interface and reduce the moving speed of hole, the recombination of hole and electronic ate made in the omitting layer. Compared with the devices without buffer layer, the turn-on voltage was lowered by 1.0(V) doc to the introduction of buffer layer Since the quantum well structure is formed in front of cathode to optimize the tunneling effect, there is improved the power efficiency more than two times.

3C-SiC 완충층을 이용한 AIN 박막의 결정성장 (Crystal growth of AlN thin films on 3C-SiC buffer layer)

  • 이태원;정귀상
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.346-347
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    • 2007
  • Aluminum nitride (AlN) thin films were deposited on Polycrystalline (poly) 3C-SiC buffer layers using pulsed reactive magnetron sputtering. Characteristics of AlN films were investigated experimentally by means of FE-SEM, X-ray diffraction, and FT-IR, respectively. As a result, highly (002) oriented AlN thin films with almost free residual stress were achieved using 3C-SiC buffer layers. Therefore, AlN thin films grown on 3C-SiC buffer layers can be used for various piezoelectric fields and M/NEMS applications.

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버퍼층으로서 플라즈마 polythiopheneol 유기EL소자에 미치는 영향 (Effect of plasma polythiophene as a buffer layer inserted on OLEDs)

  • 박상무;이붕주;김형권;임경범;김종택;박수홍;임응춘;이은학;이덕출
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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    • pp.177-180
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    • 2002
  • The purpose of this thesis is to develope buffer materials by the plasma polymerization method. In this article the buffer materials, plasma poly thiophene(PPTh) is used to study the interface of eter/organic in organic light emitting diodes(OLED). The interface of meter/organic materials is the important and critical objectives in development of OLED. The hole transport layer was N,N'-dipheneyl-N, N'bis-(3-methypheneyl)-1,1'dipheneyl-4,4'-diamine (TPD); the host material of mission layer was 8-tris-hydroxyquinoline aluminium (Alq3). When PPTh was inserted between ITO and TPD, emission efficiency increased.

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Measuring thermal conductivity and water suction for variably saturated bentonite

  • Yoon, Seok;Kim, Geon-Young
    • Nuclear Engineering and Technology
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    • 제53권3호
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    • pp.1041-1048
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    • 2021
  • An engineered barrier system (EBS) for the disposal of high-level radioactive waste (HLW) is composed of a disposal canister with spent fuel, a buffer material, a gap-filling material, and a backfill material. As the buffer is located in the empty space between the disposal canisters and the surrounding rock mass, it prevents the inflow of groundwater and retards the spill of radionuclides from the disposal canister. Due to the fact that the buffer gradually becomes saturated over a long time period, it is especially important to investigate its thermal-hydro-mechanical-chemical (THMC) properties considering variations of saturated condition. Therefore, this paper suggests a new method of measuring thermal conductivity and water suction for single compacted bentonite at various levels of saturation. This paper also highlights a convenient method of saturating compacted bentonite. The proposed method was verified with a previous method by comparing thermal conductivity and water suction with respect to water content. The relative error between the thermal conductivity and water suction values obtained through the proposed method and the previous method was determined as within 5% for compacted bentonite with a given water content.

Basic Physicochemical and Mechanical Properties of Domestic Bentonite for Use as a Buffer Material in a High-level Radioactive Waste Repository

  • Cho, W.J.;Lee, J.O.;Chun, K.S.;Hahn, D.S.
    • Nuclear Engineering and Technology
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    • 제31권6호
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    • pp.39-50
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    • 1999
  • The physicochemical, mineralogical, hydraulic, swelling and mechanical properties of a domestic bentonite for use as the buffer material in a high-level waste repository have been measured. The bentonite is identified to be a Ca-bentonite, and the hydraulic conductivity of the compacted bentonite with the dry density higher than 1.4 Mg/㎥ is lower than 10$^{-11}$ m/s When the dry densities are 1.4 to 1.8 Mg/㎥, the swelling pressures are in the range of 6.6 to 143.5 kg/$\textrm{cm}^2$. The unconfined compressive strength is about 94 kg/$\textrm{cm}^2$, and the coefficient of volume change and the coefficient of consolidation are in the range of 0.O0249 to 0.02142 $m^2$/MN and 0.018 to 0.115$m^2$/year, respectively.

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$CeO_2$ 단일 완충층을 이용한 SmBCO 초전도테이프 제조 (Fabrication of SmBCO coated conductor using $CeO_2$ single buffer layer)

  • 김태형;김호섭;오상수;양주생;고락길;하동우;송규정;하홍수;정규동;박경채;조상흥
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.261-262
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    • 2006
  • High temperature superconducting coated conductor has multi-layer structure of protecting layer/superconducting layer/buffer layer/metallic substrate. The buffer layer consists of multi layer, and the architecture most widely used in RABiTS approach is $CeO_2$(cap layer)/YSZ(diffusion barrier layer)/$CeO_2$(seed layer). Multi-buffer layer deposition required many times and process. Therefore single buffer layer deposition study reduce 2G HTS manufacture efforts. Evaporation technique for single buffer deposition method is used for the $CeO_2$ layer. $CeO_2$ single buffer film could be achieved in the chamber. Detailed deposition conditions (temperature and partial gas pressure of deposition) were investigated for the rapid growth of high quality $CeO_2$ single buffer film.

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고준위 폐기물 처분용기 내진 해석 모델 개발 (Development of an Earthquake-Resistant Model for a High-Level Waste Disposal Canister)

  • 최영철;윤찬훈;김현아;최희주
    • 터널과지하공간
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    • 제24권4호
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    • pp.316-324
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    • 2014
  • 고준위 방사성 폐기물 처분시스템은 지하 500 m 심도에서 암반에 터널을 뚫어 고준위폐기물 처분용기를 넣고 주위를 완충재로 매우는 형태이다. 많은 통계 자료에 의하면 한반도에서 매년 지진이 증가하는 추세이며, 지진이 발생할 경우 지하에서 발생된 전단력에 의해 처분용기가 손상될 수 있다. 더 나아가 방사성 유해물질이 유출되어 큰 환경 문제가 유발될 수 있다. 이에 본 논문에서는 지진에 대해 안전하게 보호할 수 있는 방법으로 내진형 완충재를 개발하였다. 내진 성능에 영향을 미치는 주요인자를 분석하여 내진형 완충재를 설계하였고, ABAQUS를 이용하여 전단해석모델을 개발하여 내진형 완충재의 성능을 평가하였다.

유기 발광 소자에서 정공 주입 버퍼층의 효과 (Effects of Hole-Injection Buffer Layer in Organic Light-Emitting Diodes)

  • 정동희;김상걸;오현석;홍진웅;이준웅;김영식;김태완
    • 한국전기전자재료학회논문지
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    • 제16권9호
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    • pp.816-825
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    • 2003
  • Current-voltage-luminance characteristics of organic light-emitting diodes (OLEDs) were measured in the temperature range of 10 K~300 K. Indium-tin-oxide (ITO) was used as an anode and aluminum as a cathode in the device. Organic of N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine (TPD) was used for a hole transporting material, and tris (8-hydroxyquinolinato) aluminum (Alq$_3$) for an electron transporting material and emissive material. And copper phthalocyanine (CuPc), poly(3,4-ethylenedi oxythiophene);poly(styrenesulfonate) (PEDOT:PSS), and poly(N-vinylcarbazole) (PVK) were used for hole-injection buffer layers. From tile analysis of electroluminescence (EL) and photoluminesccnce (PL) spectra of the Alq$_3$, the EL spectrum is more greenish then that of PL. And the temperature-dependent current-voltage characteristics were analyzed in the double and multilayer structure of OLEDS. Electrical conduction mechanism was explained in the region of high-electric and low-electric field. Temperature-dependent luminous efficiency and operating voltage were analyzed from the current-voltage- luminance characteristics of the OLEDS.

박막형 고온초전도 선재를 위한 산화물 완충층의 IBAD_MgO 기판에서의 성장과 특성 (Growth and characterization of oxide buffer layer on IBAD_MgO template for HTS coated conductors)

  • 고락길;장세훈;하홍수;김호섭;송규정;하동우;오상수;박찬;문승현;김영철
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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    • pp.297-297
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    • 2008
  • Buffer layers play an important role in the development of high critical current density coated conductor. $LaMnO_3$, $SrTiO_3$ and $BaZrO_3$ buffer layers were compatible with MgO surfaces and also provide a good template for growing high current density REBCO(RE=Rare earth) films. Systematic studies on the influences of pulsed laser deposition parameters (deposition temperature, deposition pressure, processing gas, laser energy density, etc.) on microstructure and texture properties of $LaMnO_3$, $SrTiO_3$ and $BaZrO_3$ films as buffer layer deposited on ion-beam assisted deposition MgO (IBAD_MgO) template by pulse laser deposition method, were carried out. These results will be presented together with the discussion on the possible use of this material in HTS coated conductor as buffer.

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온도 변화를 고려한 압축 벤토나이트 완충재의 함수특성곡선 모델 평가 (An Evaluation of Soil-Water Characteristic Curve Model for Compacted Bentonite Considering Temperature Variation)

  • 윤석;전준서;고규현;김건영
    • 한국지반공학회논문집
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    • 제36권10호
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    • pp.33-39
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    • 2020
  • 심층 처분 방식은 고준위폐기물을 처분하기 위한 가장 적합한 대안으로 고려되어지고 있다. 고준위폐기물은 공학적방벽시스템에 의해 지하 500~1,000m 깊이의 암반층에 처분된다. 공학적방벽시스템의 구성 요소로는 처분용기, 완충재, 뒷채움재 및 갭채움재가 있다. 이 중 벤토나이트 완충재는 지하수 유입으로부터 처분용기를 보호하고, 방사성 핵종 유출을 저지하는 역할을 하기에 심층 처분시스템에 있어 매우 중요하다고 할 수 있다. 초기에는 처분용기로부터 발생하는 고온의 열량으로 인해 완충재의 포화도는 감소하지만, 그 후 주변 암반으로부터 유입되는 지하수로 인해 완충재의 포화도는 증가한다. 이렇듯 완충재의 불포화 거동 특성은 공학적방벽의 전체 안전성을 좌우할 수 있는 중요한 입력자료이다. 국내의 경우 경주에서 생산되는 벤토나이트가 완충재의 주요 후보물질로 고려될 수 있는데 국내 벤토나이트 완충재의 온도를 고려한 불포화 거동 특성에 대한 연구는 매우 미진한 상황이다. 따라서 본 연구에서는 국내 압축 벤토나이트 완충재의 온도 증가에 따라 함수비가 일정한 조건에서의 함수특성곡선을 도출하였으며, 시험 값과 온도가 고려된 수정 van-Genuchten 모델 값과의 상대오차는 약 2%를 나타냈다.