Ordered Structures from Nanoparticles

Abstract

In nature many colors arise from ordered structures with periodicities in the submicron range. One prominent example is the gemstone opal We discuss the origin of the brillant colors of opal and its artificial counterparts: colloidal crystals and three dimensional photonic crystals. In addition we point out possibilities how to prepare colloidal crystals and related materials with inverted structure. Such materials show promising characteristics for innovative future developments in the fields of opitcs.