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Volumn 23, Issue 5, 2007, Pages 2414-2422

Preparation, structure, and optical properties of nanoporous gold thin films

Author keywords

[No Author keywords available]

Indexed keywords

4-FLUOROBENZENETHIOL; PLANAR SUBSTRATES; RAMAN SUBSTRATES; SYNCHROTRON GRAZING INCIDENCE;

EID: 33847745103     PISSN: 07437463     EISSN: None     Source Type: Journal    
DOI: 10.1021/la062313z     Document Type: Article
Times cited : (215)

References (70)
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    • For example, see: Ulman, A. Chem. Rev. 1996, 96, 1533-1554
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    • Cardona, M, Guntherodt, G, Eds, Springer-Verlag: Berlin
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    • (1984) Light Scattering in Solids IV
    • Otto, A.1
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    • By trial and error, it was found that surface attachment of the Ag X/Au1-X alloy required a clean gold adhesion layer. Otherwise, the alloy would delaminate from the substrate during HNO3 etching. Freshly sputtered gold surfaces adhered AgX/Au1-X the best i.e, it was best to use freshly made samples as opposed to making a bunch of gold samples and then periodically cleaning one when necessary with either H2SO4:H2O2 or H 2O2:NH4OH:H2O, although in preliminary trials thermally deposited gold when used immediately usually adhered alloy upon etching
    • 2O), although in preliminary trials thermally deposited gold when used immediately usually adhered alloy upon etching.
  • 28
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    • These QCM thicknesses will be used for convenience for the sample designation throughout the text. Cross-sectional SEM images were taken for a variety of the different thicknesses to determine a direct physical thickness. Typically, the SEM thickness values were ∼0.9 of the QCM values.
    • These QCM thicknesses will be used for convenience for the sample designation throughout the text. Cross-sectional SEM images were taken for a variety of the different thicknesses to determine a direct physical thickness. Typically, the SEM thickness values were ∼0.9 of the QCM values.
  • 29
    • 33847696000 scopus 로고    scopus 로고
    • This particular configuration was recommended by the manufacturer to ensure an even coating
    • This particular configuration was recommended by the manufacturer to ensure an even coating.
  • 31
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    • Values were obtained directly from calibration data for our XPS instrument
    • Values were obtained directly from calibration data for our XPS instrument.
  • 33
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    • Sauerbrey, G. Z. Phys. 1959, 155, 206-222.
    • (1959) Z. Phys , vol.155 , pp. 206-222
    • Sauerbrey, G.1
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    • Also, EDS typically probes ∼1 mm into a sample and thin (<100 nm) films needed to be tested, so XPS was substituted for EDS since it probes the top ∼5-10 nm of a surface.
    • Also, EDS typically probes ∼1 mm into a sample and thin (<100 nm) films needed to be tested, so XPS was substituted for EDS since it probes the top ∼5-10 nm of a surface.
  • 40
    • 33847699201 scopus 로고    scopus 로고
    • For a visual simulation of the dealloying process, see
    • For a visual simulation of the dealloying process, see http://www.deas.harvard.edu/matsci/downdata/dealloying-movie.avi.
  • 41
    • 33847725722 scopus 로고    scopus 로고
    • CRC Handbook of Metal Etchants; Walker, P., Tarn, W. H., Eds.; CRC Press: Boca Raton, FL, 1991.
    • CRC Handbook of Metal Etchants; Walker, P., Tarn, W. H., Eds.; CRC Press: Boca Raton, FL, 1991.
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    • Ph.D. Thesis, The Pennsylvania State University
    • Yoon, J. Ph.D. Thesis, The Pennsylvania State University, 1997.
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    • Values of surface areas for desired etch times of given starting alloy film thicknesses can be interpolated from the complete set of data and associated plots in the Supporting Information. In general, the film thickness surface correlations are nonlinear
    • Values of surface areas for desired etch times of given starting alloy film thicknesses can be interpolated from the complete set of data and associated plots in the Supporting Information. In general, the film thickness surface correlations are nonlinear.
  • 51
    • 33847756976 scopus 로고    scopus 로고
    • This type of behavior was typical of a spinodal decomposition process. For example see: Chan, J. W, Hilliard, J. E. J. Chem. Phys. 1959, 31, 688-699 or ref 2
    • This type of behavior was typical of a spinodal decomposition process. For example see: Chan, J. W.; Hilliard, J. E. J. Chem. Phys. 1959, 31, 688-699 or ref 2.
  • 52
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    • More extensive comparisons are given in the Supporting Information
    • More extensive comparisons are given in the Supporting Information.
  • 56
    • 33847700738 scopus 로고    scopus 로고
    • The goodness of each fit was defined by the global nonlinear least squares fit error between the experimental and simulated Δ, Ψ spectra
    • The goodness of each fit was defined by the global nonlinear least squares fit error between the experimental and simulated Δ, Ψ spectra.
  • 57
    • 17144462249 scopus 로고    scopus 로고
    • Discrepancies between the simulations and the experimental data could be due to using bulk Au dielectric constants. When using EMT models with Au nanoparticles, an additional term may be required to account for either classical scattering of the conduction electrons from the particle surface as it becomes comparable to or smaller than the electron mean free path (the so-called limited electron mean free path effect) or quantum mechanically because of dipole transitions between sp electron eigenstates which become discrete as a result of the small dimensions of the particle. Briefly, a dielectric function for Au nanoparticles can be written as a combination of an interband term approximated by Lorentz oscillators accounting for the response of the d electrons and a Drude term considering the free conduction electrons, For a more detailed description see ref 53 or 54, The features in the case of np-Au could possibly be approximated by aggregated nanoparticles, so using modified optical
    • Discrepancies between the simulations and the experimental data could be due to using bulk Au dielectric constants. When using EMT models with Au nanoparticles, an additional term may be required to account for either classical scattering of the conduction electrons from the particle surface as it becomes comparable to or smaller than the electron mean free path (the so-called limited electron mean free path effect) or quantum mechanically because of dipole transitions between sp electron eigenstates which become discrete as a result of the small dimensions of the particle. Briefly, a dielectric function for Au nanoparticles can be written as a combination of an interband term approximated by Lorentz oscillators accounting for the response of the d electrons and a Drude term considering the free conduction electrons. (For a more detailed description see ref 53 or 54.) The features in the case of np-Au could possibly be approximated by aggregated nanoparticles, so using modified optical constants could result in more accurate simulations. Also, discrepancies arising from image dipole effects because of the presence of an interface or optical screening may drastically change the optical response, but better fits to experimental results have come from evaluating the optical response not with Bruggeman EMT but as a result of the presence of optical dipoles at an interface [Wormeester, H.; Kooij, E. S.; Mewe, A.; Rekveld, S.; Poelsema B. Thin Solid Films 2004, 455-456, 323-334].
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    • Also, screening parameters have been injected into the Bruggeman approximation with some success [e.g., see Lee, S.; Hong, J.; Oh, S. G. Thin Solid Films 1999, 341, 37-41]. These two modifications (more accurate optical constants and optical screening) have been pointed out as possible ways to simulate the optical response more accurately, but since they involve a rigorous treatment and were modeled to systems of spherical nanoparticles, they may not directly apply to the present case of np-Au.
    • Also, screening parameters have been injected into the Bruggeman approximation with some success [e.g., see Lee, S.; Hong, J.; Oh, S. G. Thin Solid Films 1999, 341, 37-41]. These two modifications (more accurate optical constants and optical screening) have been pointed out as possible ways to simulate the optical response more accurately, but since they involve a rigorous treatment and were modeled to systems of spherical nanoparticles, they may not directly apply to the present case of np-Au.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.