• 제목/요약/키워드: Interface reaction

검색결과 700건 처리시간 0.024초

Photo-DSC를 사용한 에틸렌글리콜 단위 길이에 따른 다이메타크릴레이트의 광중합 전환률에 미치는 온도와 광개시제 농도의 영향 (The Effect of Temperature and Photoinitiator Concentration on Conversion of Photopolymerized Multiethylene Glycol Dimethacrylate by Photo-DSC)

  • 도현성;김대준;김현중;이영규
    • 접착 및 계면
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    • 제4권3호
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    • pp.14-20
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    • 2003
  • UV 경화에 사용되는 poly(ethylene glycol 400) dimethacrylate(PEGA400DMA)와 ethylene glycol dimethacrylate(EGDMA)를 사용하여 모노머(monomer)의 종류에 따른 경화거동과 광개시제의 양과 온도에 따른 경화 거동을 photo-DSC를 사용하여 살펴보았다. Ethylene glycol의 단위길이가 늘어날수록, 광개시제의 양이 증가할수록, 반응 온도가 높을수록 경화속도가 빠르게 일어났다. 또한 PEG400DMA의 반응속도가 EGDMA보다 느리게 나타났지만 전환률은 높게 나타남을 알 수 있었다.

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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.