Preparation, characterization and photoluminescence properties of ultra long SiC/SiOx nanocables

SiC core and SiOx shell nanocables of a few millimeters long have been prepared by pyrolysis of SiO2 nanopowder added poly(dimethyl siloxane) without catalyst in a tube furnace at 1050 °C in Ar. The influence of the synthesis conditions (synthesis temperature and cooling time) on the products is studied. The products obtained from different conditions are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution electron microscopy equipped with energy dispersive X-ray spectroscopy, and photoluminescence spectroscopy. The results show that the cores and the shells are crystalline and amorphous, respectively, and that the addition of SiO2 nanopowder and prolongation of cooling time both increase the diameter of the cores. The growth process of the nanocables is discussed. The photoluminescence emission bands of the nanocables are mainly from their shells.