Effects of Doping on Optical Properties of Colloidal Crystals

High-quality Polystyrene(PS) colloidal crystal multilayers have been fabricated from aqueous solutions by the vertical deposition method at proper temperature and humidity. In this letter, impurities have been introduced into these crystals by doping to break the periodic spatial variation of the dielectric index. This system provides a simple way to study 3D photonic band structure effects with complete control over impurities in the lattice. This may prove to be a significant advantage if control over sample impurity provides an avenue for tuning the optical properties.