Opaline Photonic Crystals: How Does Self‐Assembly Work?

Abstract

Thin opaline films (see Figure), which are self-assembled from colloidal microspheres, have recently been used to explore the properties of photonic crystals. However, the detailed growth mechanism of these opals is not known. Here the underlying issues involved in the growth are discussed, and it is suggested that solvent flow, which to date has not been seriously considered, could play a critical role in controlling the formation process.