Template-Induced Growth of Close-Packed and Non-Close-Packed Colloidal Crystals during Solvent Evaporation

Abstract

Template-induced colloidal deposition during solvent evaporation is a promising technique for extending the possibilities of nanosphere lithography and the creation of photonic band gap materials. We investigated the influence of the parameters that determine the surface topography of templates on colloidal crystal structure. On pillar-shaped templates, large defect-free square symmetric monolayers, ordered vacancy arrays, and body-centered cubic (bcc) and simple cubic (sc) colloidal crystals could be grown. Close-packed crystals displayed defects and large defect grains. Our results indicate that this may be avoided when the direction of gravity with respect to the substrate is changed. The ability of colloids to self-assemble into 2D and 3D crystalline structures lies at the heart of many studies in nano-and micrometer-scale materials science.1 Especially in the field of photonic band gap materials, colloidal crystals are being routinely used.2 Furthermore, 2D and thin 3D colloidal crystals can be used as a mask for creating regular arrays of nanometer-sized features with a technique called nanosphere lithography.3-5 One of the simplest and most frequently used