Light diffraction in nanoshell colloidal metal-dielectric photonic crystals

Abstract

3-dimensional metal-dielectric photonic crystals of different topologies have been prepared by infiltration of colloidal crystals with gold nanoparticles and using nanoshell approach. The angle-resolved light reflectance has been studied. Development of reflectance bands interpreted as the localized surface plasmon resonances of Au nanoparticles and nanoshells along the increase of the Au nanoparticle concentration has been observed. The effective dielectric constant of these photonic crystals has been estimated from the angle dispersion of the diffraction resonance. Depending on the Au nanoparticle content and the geometry, the effective dielectric constant changes from the negative to the ..