Tuning the morphologies of SiC nanowires via the control of growth temperature, and their photoluminescence properties

Single crystalline SiC nanowires were synthesized by a catalyst free vapor deposition method using elemental silicon and graphite carbon as the starting materials. The phase, morphology, crystal structure, and defects of the products were characterized by x-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Within a 6 h reaction time, the morphology of the SiC nanowires can be tuned to cylinder, hexagonal prism, or bamboo shape by simply altering the reaction temperature from 1470 degrees C, 1550 degrees C to 1630 degrees C, respectively. The photoluminescence of these differently shaped SiC nanowires was measured and is discussed. Based on the characterization results, the vapor-solid growth mechanisms for the multi-shaped SiC nanowires are proposed by taking into account the possible reactions between intermediate gas phases, the reaction steps, and the surface energy minimization.