• Title/Summary/Keyword: LB Monolayer

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A Study of the Photoelectrochemical Effects of Squaraine Aggregate in Monolayer (스쿠알렌 집합체의 광전기화학적 효과에 관한 연구)

  • Young Soon Kim;Kock-Yee Law;David G. Whitten
    • Journal of the Korean Chemical Society
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    • v.37 no.7
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    • pp.642-647
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    • 1993
  • Monolayers of pure surfactant squaraine, DSSQ(4-distearyl amino phenyl-4'-dimethylaminophenylsquaraine), were deposited on $SnO_2 $ electrodes by the Langmuir-Blodgett film technique. The DSSQ film exhibits ${\lambda}_{max}$ at ∼530 nm. The absorption is significantly red-shifted from the solution of DSSQ (633 nm in chloroform), suggesting that the squaraine chromophores form aggregates in the LB film. The photogeneration of the squaraine aggregates is studied by measuring the photocurrents in photoelectrochemical cells consisting of the squaraine of the aggregates is found to parallel its absorption spectrum and quantum efficiency as high as 0.3% has been observed. While the photocurrent was attenuated exponentially when stearic acid layers (up to 8 layers) are inserted between the squaraine layer and the electrode, it is nearly extinguished when the squaraine layer is over-coated with 2 layers of stearic acid. A model for the observation is proposed and the roles of the electrolytes and oxygen on the photogeneration process will be discussed.

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