Size dependent surface plasmon resonance broadening in non-spherical nanoparticles: Single gold nanorods

The spectral response of metallic nanoparticles is dominated by the Localized Surface Plasmon Resonance (LSPR). While its spectral position is well understood, measuring and interpreting the LSPR linewidth evolution with shape and size is still an important issue for both fundamental investigations and applications. It needs the use of single particle experiments on nanoparticles with a well controlled environment, to avoid inhomogeneous broadening and/or spurious effects. The dominant effect related to size reduction is an increase of the surface contribution to the linewidth of the LSPR, due to the quantum confinement of the electrons.