Light scattering investigation of 2D and 3D opal template formation on hydrophilized surfaces

We demonstrate the formation of 2D photonic crystals (opals) on gold coated silicon substrates by dip-coating at a high rate of 1 mm/min when the surfactant sodium dodecyl sulphate (SDS) is added to the solution above its critical micelle concentration. The dependence of substrate hydrophillicity is demonstrated to influence the formation of 3D templates on glass substrates using 700 nm diameter PMMA spheres. Other routes towards directing opal assembly are also discussed. Angle-resolved reflectance shows 2D and 3D light scattering characteristics from the fast-rate dip-coated monolayer 2D 3D photonic crystals grown on hydrophillized glass respectively, with a high degree of surface ordering.