1. Laser induced enhancement of dichroism in supported silver nanoparticles deposited by evaporation at glancing angles.
- Author
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Filippin, A. Nicolas, Borras, Ana, Rico, Victor J., Frutos, Fabian, and González-Elipe, Agustin R.
- Subjects
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SILVER nanoparticles , *SURFACE plasmon resonance , *SCANNING electron microscopy , *DICHROISM , *ATOMIC force microscopy - Abstract
Silver nanoparticles (NPs) depicting well defined surface plasmon resonance (SPR) absorption were deposited on flat substrates by physical vapor deposition in a glancing angle configuration. The particles were characterized by scanning electron microscopy and atomic force microscopy and their optical properties examined by UV-vis absorption spectroscopy using linearly polarized light. It was found that, depending on the amount of deposited silver and the evaporation angle, part of the 'as-prepared' samples present NPs characterized by an anisotropic shape and a polarization dependent SPR absorption and different colors when using polarized white light at 0° and 90°. Low-power irradiation of these materials with an infrared Nd-YAG nanosecond laser in ambient conditions produced an enhancement in such dichroism. At higher powers, the dichroism was lost and the SPR bands shifted to lower wavelengths as a result of the reshaping of the silver NPs in the form of spheres. The possible factors contributing to the observed changes in dichroism are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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