Photoluminescence and structural properties of Si/SiC core–shell nanowires growth by HWCVD

Abstract

Si/SiC core–shell nanowires grown by hot-wire chemical vapor deposition were studied. Ni nanoparticles act as metal nano-templates to catalyze the growth of these core–shell nanowires. These nanowires were grown at different deposition pressures of 0.5 and 1mbar. The nanowires showed a tapered-like morphology at deposition pressure 0.5mbar. Increase in pressure to 1mbar leads to a formation of agglomerated grains at the root of the nanowires. The results show that these nanowires consisted of crystalline Si core and amorphous SiC shell nanowires. Increase in pressure enhanced the formation of SiC phase in the shell of the nanowires. On the other hand, the formation of the agglomerated grains attributed to an increasing of the SiC phase at higher deposition pressure. The presence of Si and SiC nano-crystallites embedded within an amorphous matrix exhibited a room temperature PL emission in the range of 400–1000nm. The effects of the deposition pressure on the optical and structural properties of the nanowires are also discussed.