Elastic Scattering of Gold and Silver Colloids: Difference between Spherical and Nonspherical Nanoparticles

Light scattering of noble metal nanoparticles was widely used in solar cells, sensing and spectroscopy, so the research on the light scattering itself will be beneficial for their increasing applications. In this paper, gold and silver nanoparticles with different sizes and shapes were synthesized and their elastic scattering was investigated. The results demonstrate that the elastic scattering of metal nanoparticles is influenced by their size and shape, and the scattering behavior has a specific correlation with the surface plasmon resonance. The elastic scattering spectra of gold and silver nanospheres basically cover the extinction spectra, indicating plasmon resonance enhanced scattering of spherical nanoparticles. The elastic scattering spectra of nonspherical gold nanorods and silver nanoprisms only overlap the extinction peaks at short wavelengths. The elastic scattering is considered to be enhanced by the transverse resonance bands at short wavelengths for nonspherical gold or silver nanoparticles, but it cannot be contributed by the longitudinal resonance bands at the corresponding long wavelengths. This result will be helpful in selecting size and shape in the scattering application of plasmonic metal nanoparticles.