Introduction of three-dimensional extrinsic defects into colloidal photonic crystals

Abstract

An effective and simple method for engineering micrometer-scale three-dimensional extrinsic defects within self-assembled colloidal photonic crystals (PC) was demonstrated. The method combines the techniques of self-assembly of colloidal spheres, photolithography on a preformed colloidal crystal, templated-directed colloidal crystal growth, and sequential growth of colloidal crystal. The vertical deposition or spin-coating was employed to grow polystyrene (PS) colloidal crystal within the channels. The PS spheres were synthesized using an emulsifier-free emulsion polymerization technique. Heterostructured colloidal crystals are expected to exhibit elaborate optical properties because of different PBG effects between the host and guest opal structures.