Kaito Nakane

Shape modification of Si nanowires by using faceted silicide catalysts nucleated in Au-Si catalyst solution during the growth

The shape modification of Si nanowires is demonstrated using faceted solid silicide catalysts. The Si nanowires were grown on Si(111) substrates covered with Au as a catalyst using MnCl2 and Si powders as source materials. The solid silicide catalysts were nucleated and formed in the Au-Si catalyst solution at the top of the nanowires during the growth. The faceted solid silicides grew larger with increased growth time and played a role as a solid catalyst. The faceted shape of the catalyst defines the shape of the faceted Si nanowire. The squared Si nanowires were grown with the growth direction of Si[111] and the sidewalls of {110} and {211} planes. The growth evolution of the faceted Si nanowires occurs by a vapor-liquid-solid mechanism followed by the silicide vapor-solid-solid mechanism.

Syntheses and Structural Control of Silicide, Oxide and Metallic Nano-Structured Materials

The structural control and morphological modification of a series of silicide, oxide and Ag metal nanostructures have been further discussed with reviews of nanostructure syntheses, such as CrSi2 nanowire bundles dendrites, MoSi2 nanosheets, α-Fe2O3 nanowires nanobelts, CuO/Cu2O nanowire axial heterostructures, ZrO2/SiOx and CrSi2/SiOx core/shell nanowires. In addition, the syntheses of Ag three-dimensional dendrites, two-dimensional dendrites, two-dimensional fractal structures, particles and nanowires also were discussed. Moreover, the structural and morphological properties of the nanostructures were examined. The structural control and morphological modifications of the nanostructures have been successfully demonstrated by the appropriate thermal treatments with specific starting materials. A large volume of silicide nanowire bundles, large area of oxide nanowire arrays and large area Ag nanostructure coatings were successfully fabricated.