Bulk synthesis of a-SixNyH and a-SixOy straight and coiled nanowiresElectronic supplementary information (ESI) available: Movies taken using a microscope. File RI19, shows a white fringe (Becke Line), which surrounds the particle, shift into the particle when the lens is moved farther away from focus. This indicates that the RI of the particle is greater than the surrounding calibration solution (RI = 1.9). Files RI21 and RI23 show the Becke line moving from the particle into the surrounding indicating that the RI of the particle is lower than its surrounding RI of 2.1 and 2.3 respectively. See http://www.rsc.org/suppdata/jm/b3/b311887h/

Abstract

We report the bulk synthesis of hydrogenated, amorphous SixNy and SixOy nanowires using pools of molten gallium as the solvent medium and microwave plasma consisting of silane in nitrogen and silane in oxygen respectively. High densities of multiple nanowires nucleated and grew from molten gallium pools. The resulting nanowires were tens of nanometers in diameter and tens of microns long. Electron energy loss spectroscopy (EELS) and Fourier transform infra-red (FTIR) spectroscopy showed that the silicon nitride nanowires are hydrogenated amorphous silicon nitride (a-SixNyH). The results of energy dispersive X-ray spectroscopy (EDS) yielded N ∶ Si and O ∶ Si ratios less than the stoichiometric composition of silicon nitride (Si3N4) and silica (SiO2). Studies on the chemical stability and refractive index (RI) measurements demonstrate a-SixNyH nanowires are potential candidates for use as etching masks in nanoscale lithography, and as high index materials in optical coatings.