Self-organizing three-dimensional colloidal photonic crystal structure with augmented dielectric contrast

We demonstrated that low-velocity quasi-equilibrium evaporation of water from an aqueous colloidal solution of polystyrene microparticles with 220 nm diameter enabled the preparation of a three-dimensional colloidal-air photonic crystal structure without significantly distorting the lattice, and the absorption peak of the structure was observed at around 500 nm. A much stronger photonic band gap effect is expected due to an approximately 30% increase of the dielectric contrast.