Atomic layer deposition for the fabrication of 3D photonic crystals structures: Growth of Al₂O₃ and VO₂ photonic crystal systems

In order to highlight the way in which atomic layer deposition (ALD) methods may be used to prepare complex 3D structures, we consider the modification of photonic crystals such as synthetic opals that may be readily prepared from monodispersed assemblies of colloidal particles. In such materials it is well established that the photonic gap can be significantly influenced by the infiltration of the voids within the photonic crystal with a material of higher dielectric constant. In this paper we highlight the ALD infiltration of photonic crystals with Al₂O₃ and VO₂, discussing our findings in the light of previous studies of photonic crystal infiltration. We briefly comment on the morphology of the resulting deposits in relation to the growth method employed to grow them.