Optical and crystallographic properties of inverse opal photonic crystals grown by atomic layer deposition

We report a technique for the formation of infiltrated and inverse opal structures that produces high quality, low porosity conformal material structures. ZnS:Mn and TiO₂ were deposited within the void space of an opal lattice by atomic layer deposition. The resulting structures were etched with HF to remove the silica opal template. Infiltrated and inverse opals were characterized by SEM, XRD, and transmission/reflection spectroscopy. The reflectance spectra exhibited features corresponding to strong low and high order photonic band gaps in the (111) direction (Γ-L). In addition, deliberate partial infiltrations and multi-layered inverse opals have been formed. The effectiveness of a post-deposition heat treatment for converting TiO₂ films to rutile was also studied.