Improving the opal-based photonic crystals by noise-assisted crystallisation

Crystal ordering of colloidal self-assembled photonic crystals fabricated by vertical drawing deposition technique has been improved following application of acoustic noise vibrations. The scanning electron microscopy has confirmed the improvement in the crystal order on the surface (111) plane and has demonstrated that thin opal films crystallized under acoustic agitation consist of similarly oriented crystallites, the characteristic transverse dimension of which is larger compared to that of sample grown without acoustic field. Three-dimensional lattice arrangement of the opal crystal has been examined by means of laser diffraction and optical transmission spectroscopy. Novel approach towards optical characterisation of the opal crystallinity has been suggested.