Face-Centered-Cubic Artificial Opal Embedded with CdS QuantumDots

Highly monodispersed colloidal silica spheres in sub-micrometer size with distribution standard deviation less than 5% were synthesized by a chemical method. Using the self-crystallization of the silica spheres, we successfully obtained the three-dimensional close-packed fcc silica matrices and artificial opals. Then, a colloidal photonic crystal embedded with CdS quantum dots (QDs) was also chemically prepared by using artificial opals as a template. A reflection spectra study reveals that both artificial opals with and without CdS QDs possess (111) directional photonic bandgap features.