Absorption and Scattering of Light by Silver and Gold Nanodisks and Nanoprisms

Abstract

We study the influence of the shape of silver and gold nanoparticles on the spectra of absorption and scattering of the optical-range electromagnetic radiation. We perform numerical calculations of the cross sections of absorption and scattering of light on the basis of the FDTD method for the particles having the shape of a disk and a triangular prism. We establish that the positions of plasmon resonance peaks and the spectral distributions of intensities differ significantly for nanoparticles of different shapes even when the characteristic sizes of the particles are equal. The calculations carried out thus demonstrate that, along with the size and material of the plasmonic particle, its shape is yet another factor that essentially determines its optical features. The results of the study can be utilized in the development of the spectroscopic method of determining the shape of the metal nanoparticles and the quantitative estimate of their characteristic sizes.