Abstract
Self-assembled epitaxial silicon nanowires on the surface of Si(001) have been grown and discuss on how the effect of density and size of Au nanodot catalysts for these nanowires can influence their growth. The possible growth mechanism is discussed in detail based on the VLS for self-assembled epitaxial silicon nanowires. In addition, we fabricate room temperature ferromagnetism of Mn+-implanted Si nanowires by ion implantation. The saturation magnetization was found to increase with the Mn concentration. Appropriate annealing condition can heal the displacement damage and increase the saturation magnetization in the Mn+-implanted Si nanowires. Single-crystal Ni2Si, Ni3Si2, Ni31Si12, and Ni3Si nanostructures including nanobranches, nanowires and nanobelts were synthesized by a chemical vapor deposition (CVD) method. The experimental observation suggests that vapor pressure of the nickel precursor was critically important in the morphology of silicide NWs. The studies for these silicide nanostructures mainly focus on synthesis, structure characterization, and electrical measurements. In addition, using the method of comparison of the experimental high-resolution TEM images with the simulated images, the thickness of nanobelts could be determined. Large-area ordered porous Ga2O3 films on silicon substrates were grown based on colloidal template and direct solution dipping methods. The structure has a high specific surface area to enhance the sensitivity of Ga2O3 in detecting NO2 at 200 oC. The thickness and morphologies of the samples can be controlled by the solution concentration. The results show great potential of these ordered nano-materials in sensing, photonic and optoelectronic applications.