Synthesis and optical properties of sub-micrometer silver spheres with controlled surface morphology

Synthesis of sub-micrometer spherical particles (SSP) of Ag is complicated because Ag grows withcrystalline facets at sub-micrometer dimensions. Here using of optical measurement, we show that SiO2@Ag SSPs havebroadband optical extinction spectra similar to those of Ag SSPs in visible and infrared wavelengths. This is valid ifthickness of Ag shell is larger than the skin-depth of light in Ag. We controlled the surface morphology of Ag SSPs byadjusting the reduction rate of Ag salt. Optical measurements revealed that optical extinction spectra of the particlesbecome broader when an Ag shell with large grains forms. We suggest that SiO2@Ag SSPs can be used as efficientscattering elements in enhanced solar light absorption with minimized optical dissipation in Ag.

Keywords:

Surface plasmon resonance , core-shell nanoparticles , light scattering , chemical reduction