Full Processing of colloidal photonic crystals by spin-coating

Herein we present different results on the application of spin-coating to the processing of thin films made of spherical colloids ordered in three dimensional structures. We focus on the infiltration and controlled introduction of optical planar defects. We show that the use of spin-coating largely diminishes the processing time scales typically used in the field of colloidal crystals, and still allows one to attain high quality structures. We demonstrate that spin-coating permits the controlled infiltration of colloidal crystals with many different types of compounds. Examples are given for different oxide and polymer guest compounds introduced in the voids of the colloidal lattices. Both scanning electron microscopy and optical spectroscopy evidence of such control are provided. We also show that a thin layer of particulate material can be spread onto a colloidal crystal by spin coating a suspension of such particles in which control over the aggregation state has been achieved first. This gives rise to a capped lattice that present surface resonant modes and can be used to build a planar defect embedded in the bulk. In all cases, evidence of the optical quality of the different samples made is provided.