Ultrafast Dynamics of Au Nanopyramid Interfaces Prepared by Nanosphere Lithography: Effect of Substrate Chemical Composition

Autor(es)

Ferbonink, Guilherme F. ^[1] ; Spada, Edna R. ^[2] ; dos Santos, Diego P. ^[1] ; Sartorelli, Maria L. ^[3] ; Nome, Rene A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Quim, CP 6154, BR-13083970 Campinas, SP - Brazil

^[2] Univ Fed Santa Catarina, Ctr Ciencias Fis & Matemat, Dept Fis, BR-88040900 Florianopolis, SC - Brazil

^[3] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13566590 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Brazilian Chemical Society; v. 27, n. 2, p. 423-433, FEB 2016.
• Citações Web of Science: 1

Resumo

This work describes ultrafast spectroscopy studies of Au triangular pyramid particle arrays deposited over glass (termed Au/glass), and 190 nm indium tin oxide (ITO) film (termed Au/ITO/glass) prepared by nanosphere lithography. The linear absorption spectra of Au/glass and Au/ITO/glass exhibit surface plasmon resonances at 800 and 870 nm, respectively, in good agreement with discrete dipole approximation simulations. Ultrafast pump-probe measurements at wavelengths below resonance, at resonance, and above the surface plasmon resonance for each of these two systems are presented. The pump-probe measurements on both systems can be well fit with a model accounting for electron-electron scattering, electron-phonon coupling, and acoustic oscillations on top of cooling of the gold lattice. Numerical simulations employing a two-temperature model are consistent with the single-color pump-probe exponential decays. The wavelength-dependent pump-probe results are interpreted in terms of the complex wavelength-dependent refractive index of gold. We show that this interpretation is consistent with diffractive-optic four-wave mixing spectroscopy measurements of absorptive and dispersive parts of the third-order nonlinear polarization at 800 nm. (AU)

• Processo FAPESP: 08/10593-0 - Medindo a dinâmica química de líquidos através de espectroscopia ultrarrápida
• Beneficiário: René Alfonso Nome Silva
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores