Three-dimensional ordered silicon-based nanostructures in opal matrix: preparation and photonic properties

Abstract Three-dimensional ordered opal–Si nanocomposites with direct (opal voids are infilled with silicon) and inverted (opal skeleton is removed from the initial composite) structures have been synthesized. The thermal chemical vapor deposition technique is used to incorporate silicon into the voids. An electron microscopy analysis reveals a uniformly thick silicon layer on the inner surface of opal voids. Maxima in the reflection spectra from the (1 1 1) surface of the composites are shown to arise due to the Bragg diffraction of light. These maxima are interpreted as a manifestation of photonic band gap that is tunable in position and width by varying the fill factor of the opal voids.