Spontaneous Emission of Terbium Complex In-Filled in Single-Crystal Colloidal Multilayer

Highly monodisperse submicron-sized silica spheres were synthesized by a chemical method, and single-crystal colloidal multilayers were prepared by a vertical deposition technique. Rare earth complex Tb(ACAC)3phen was in-filled in this structure to investigate the photonic bandgap effect on the spontaneous emission. The photon density of states in the photonic crystal was calculated numerically to investigate the origin of the abnormally enhanced photoluminescence in the photonic bandgap region. Our results are suggestive of a new way to probe the position of fluorescent molecules in such photonic bandgap materials.