Layer-by-layer templated growth of colloidal crystals with packing and pattern control

Layer-by-layer deposition of polymer colloidal particles on patterned electrode surfaces under an applied electric field is discussed. Colloidal crystals with a low packing density, grown on hexagonally patterned electrode substrates from single-sized colloidal particles, are presented. A nucleation mechanism of colloidal layer formation determined the grain size of the colloidal crystals. Alternating deposition of large (L) and small (S) colloidal particles with radii ratios of RS/RL = 0.41 and 0.49 on patterned surfaces with hexagonal and square types of pattern led to the formation of 2D and 3D binary colloidal crystals with LS, LS2 and LS3 stoichiometries. Planar defects in form of colloidal monolayers composed of colloidal particles of smaller sizes were easily introduced into colloidal crystals using the layer-by-layer deposition technique. This method allows one to fabricate stable non-close-packed colloidal crystal structures in a direct deposition process.