• Caruso, Frank
• Wang, Dayang
• Li, Jensen Tsan Hang
• Chan, Che Ting
• Sagueirino-Maceira, Verónica
• Romanov, Sergei G.
• Liz-Marzán, Luis M.

Abstract

Metallodielectric inverse opals were prepared by co-crystallizing silica-coated gold nanoparticles and polymer spheres, followed by removal the crystal template. The inverse opals exhibit a distinct reflectance peak, which results from Bragg diffraction due to the highly ordered 3D macro porous structure. Photonic band-structure calculations indicate that the characteristic reflectance peaks observed are signatures of the directional gap at the L point. It is demonstrated that the optical properties (the position and magnitude of the electromagnetic bandgaps) of the gold-silica nanocomposite inverse opals can be engineered by varying the nanoparticle morphology (core size and shell thickness) and/or the nanoparticle volume-filling ratio of the composite. The use of metallodielectric nanoparticles to form inverse opals offers a versatile approach to prepare photonic materials that may exhibit absolute bandgaps.

Topics

• nanoparticle
• porous
• nanocomposite
• impedance spectroscopy
• polymer
• gold