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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Comparative study on the far-field spectra and near-field amplitudes for silver and gold nanocubes irradiated at 514, 633 and 785 nm as a function of the edge length

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Hermoso, W. [1] ; Alves, T. V. [1] ; Ornellas, F. R. [1] ; Camargo, P. H. C. [1]
Total Authors: 4
[1] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, BR-05508000 Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: EUROPEAN PHYSICAL JOURNAL D; v. 66, n. 5 MAY 2012.
Web of Science Citations: 17

We describe a systematic investigation by the discrete dipole approximation on the optical properties of silver (Ag) and gold (Au) nanocubes as a function of the edge length in the 20-100 nm range. Our results showed that, as the nanocube size increased, the plasmon resonance modes shifted to higher wavelengths, the contribution from scattering to the extinction increased, and the quadrupole modes became more intense in the spectra. The electric field amplitudes at the surface of the nanocubes were calculated considering 514, 633 and 785 nm as the excitation wavelengths. While Ag nanocubes displayed the highest electric field amplitudes (vertical bar E vertical bar(max)) when excited at 514 nm, the Au nanocubes displayed higher vertical bar E vertical bar(max) values than Ag, for all sizes investigated, when the excitation wavelength was either 633 or 785 nm. The variations in vertical bar E vertical bar(max) as a function of size for both Ag and Au nanocubes could be explained based on the relative position of the surface plasmon resonance peak relative to the wavelength of the incoming electromagnetic wave. Our results show that not only size and composition, but also the excitation wavelength, can play an important role over the maximum near-field amplitudes values generated at the surface of the nanocubes. (AU)

FAPESP's process: 11/06847-0 - Multimetallic nanostructures with hollow interiors and well-defined sizes, shapes and compositions
Grantee:Pedro Henrique Cury Camargo
Support type: Regular Research Grants