Strong broadband scattering of anisotropic plasmonic nanoparticles synthesized by controllable growth: Effects of lumpy morphology

Strong scattering intensities in a broadband wavelength range from metallic nanoparticles are essential for diverse photonics applications. Conventional ways of controlling particle scattering are via the control of the size, shape and embedding dielectric environment. In this paper we demonstrate that tailoring the particle surface roughness is another effective way of controlling particle scattering. Roughly surfaced lumpy silver nanoparticles, which have anisotropic surface topography, are realized by a controlled shape-and size-selective wet chemical method. Through the systematic comparison with the smoothly surfaced nanoparticles of the same size and size distribution, we verify both experimentally and theoretically that the lumpy nanoparticles produce large-angle broadband plasmonic scattering due to their unique surface anisotropic structure.