Two-dimensional ordered arrays of silicon nanoparticles

Nanosized silica particles of various diameters (40, 60, and 105 nm) with r elatively narrow size distributions were prepared via base-catalyzed sol-ge l reactions of tetraethyl orthosilicate using a seeded-growth technique. Th ese nanoparticles were organized into two-dimensional (2-D) monolayers by a solvent evaporation method. The particles of 60 nm or greater in, diameter could be assembled to 2-D crystals on a larger area because of lower parti cle size distribution. The arraying order was found to have little or no de pendence on shape regularity of the nanoparticles, pH value, and type of th e substrate, including microslide, silicon wafer, and indium-tin oxide glas s, used in this study.