Synthesis of β-Silicon carbide nanowires by a simple, catalyst-free carbo-thermal evaporation technique

β-SiC nanowires were successfully fabricated on pare Si (100) substrate using simple carbo-thermal evaporation of graphite at 1200°C. The obtained β-SiC nanowires were aligned with diameters ranged between 40 to 500 nm. The majority of crystal planes were β-SiC (111) with other less intensity of (200), (220) and (311). The silicon substrate location inside the furnace found to be critical in the formation of the β-SiC nanowires. Also, FTIR absorption peaks for β-SiC nanowires found at higher frequency side of 1110 cm-1 which is pointed to Si-O asymmetric stretching mode. © 2012 Penerbit UTM Press. All rights reserved

Direct growth and Photoluminescence of SiOx nanowires and aligned nanocakes by simple carbothermal evaporation

The growth of SiOx nanowires and nanocakes on an Au-coated n-type-Silicon (100) substrate was achieved via carbothermal evaporation. The effects of the Au layer thickness and the rapid heating rate on the morphology of obtained SiOx nanowires were investigated. A broad emission band from 290 to 600 nm was observed in the photoluminescence (PL) spectrum of these nanowires. There are four PL peaks: one blue emission peak 485 nm (2.56 eV) two green bands centered at 502 nm (2.47 eV) and 524 nm (2.37 eV) for nanocakes and one ultraviolet emission peak at 350 nm (3.54 eV) and a hemisphere curve over the bluish green area taken for SiOx nanowires. These emissions may be related to the various oxygen defects and twofold coordinated silicon lone pair centers