• 제목/요약/키워드: Interface reaction

검색결과 698건 처리시간 0.039초

양자점 감응 태양전지의 광전 특성 향상을 위한 ZnS/SiO2 이중 오버레이어 개발 (Development of ZnS/SiO2 Double Overlayers for the Enhanced Photovoltaic Properties of Quantum Dot-Sensitized Solar Cells)

  • 송인철;정성목;서주원;김재엽
    • 한국수소및신에너지학회논문집
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    • 제32권6호
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    • pp.656-662
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    • 2021
  • For the high efficiencies of quantum dot-sensitized solar cells (QDSCs), it is important to control the severe electron recombination at the interface of photoanode/electrolyte. In this work, we optimize the surface passivation process of ZnS/SiO2 double overlayers for the enhanced photovoltaic performances of QDSCs. The overlayers of zinc sulfide (ZnS) and SiO2 are coated on the surface of QD-sensitized photoanode by successive ionic layer adsorption and reaction (SILAR) method, and sol-gel reaction, respectively. In particular, for the sol-gel reaction of SiO2, the influences of temperature of precursor solution are investigated. By application of SiO2 overlayers on the ZnS-coated photoanode, the conversion efficiency of QDSCs is increased from 5.04% to 7.35%. The impedance analysis reveals that the electron recombination at the interface of photoanode/electrolyte is obviously reduced by the SiO2 overlayers.

Epitaxial growth of yttrium-stabilized HfO$_2$ high-k gate dielectric thin films on Si

  • Dai, J.Y.;Lee, P.F.;Wong, K.H.;Chan, H.L.W.;Choy, C.L.
    • E2M - 전기 전자와 첨단 소재
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    • 제16권9호
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    • pp.63.2-64
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    • 2003
  • Epitaxial yttrium-stabilized HfO$_2$ thin films were deposited on p-type (100) Si substrates by pulsed laser deposition at a relatively lower substrate temperature of 550. Transmission electron microscopy observation revealed a fixed orientation relationship between the epitaxial film and Si; that is, (100)Si.(100)HfO$_2$ and [001]Si/[001]HfO$_2$. The film/Si interface is not atomically flat, suggesting possible interfacial reaction and diffusion, X-ray photoelectron spectrum analysis also revealed the interfacial reaction and diffusion evidenced by Hf silicate and Hf-Si bond formation at the interface. The epitaxial growth of the yttrium stabilized HfO$_2$ thin film on bare Si is via a direct growth mechanism without involoving the reaction between Hf atoms and SiO$_2$ layer. High-frequency capacitance-voltage measurement on an as-grown 40-A yttrium-stabilized HfO$_2$ epitaxial film yielded an dielectric constant of about 14 and equivalent oxide thickness to SiO$_2$ of 12 A. The leakage current density is 7.0${\times}$ 10e-2 A/$\textrm{cm}^2$ at 1V gate bias voltage.

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SiO$_2$-CaO-Al$_2$O$_3$계 유리 솔더에 의한 알루미나의 접합 현상에 관한 연구 (A Study for Joining of Alumina Soldered by SiO$_2$-CaO-A1$_2$O$_3$ Glasses)

  • 안병국
    • Journal of Welding and Joining
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    • 제21권2호
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    • pp.35-41
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    • 2003
  • Sintered alumina ceramics were joined by 2 kinds of SiO$_2$-CaO-A1$_2$O$_3$ glass solders having a similar expansivity as alumina. Wetting of glass/alumina was examined by sessile drop method. The observation of interface and bending strength related to alumina/glass/alumina systems were investigated by means of SEM/EDX and 4-point bending test. the result are summarized as follow: (1) Wetting of glass solders on alumina was good at temperatures higher than 145$0^{\circ}C$. (2) When the joining temperature wan high, diffusion and/or reactions between solder md alumina took place at the interface. These diffusions and reactions occurring at the interface greatly affected the bending strength of joining body. (3) Highest strength corresponding to 80% that of alumina was obtained by the solder of 35SiO$_2$-35CaO-30A1$_2$O$_3$(wt%) glass.

콘크리트 충전 강관을 갖는 프리스트레스트 합성형 거더의 강-콘크리트 계면 거동 (Nonlinear Finite Element Analysis of Composite Girder with Concrete Infilled Tube)

  • 신동훈;김영훈;이타;강병수;이용학
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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    • pp.386-389
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    • 2006
  • Prestressed composite girder bridges with concrete infilled steel tube at negative flexural moment region takes the advantages of enhancing local buckling and flexural resistances resulting from the lateral confining effect of concrete due to the interactive reaction in the interface layer of steel tube and concrete. The interface behavior in concrete infilled tube of the test composite girder is analyzed by 8-node zero thickness interface finite element combined with 3-D. elastoplastic concrete constitutive model and 3-D. elastoplastic Mindlin shell element. The interface effects between infillled concrete and steel tube are investigated through the comparision of the experimental and numerical results.

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