SiC nanowires in large quantities: Synthesis, band gap characterization, and photoluminescence properties

Silicon carbide nanowires (SiCNWs) were synthesized in large quantity using a thermal process with carbon nanotube (CNT)/Si-SiO2 (carbon nanotubes grown on Si-SiO2 core-shell substrates) at 1300 degrees C in an argon atmosphere. The characterization shows that the SiCNWs covered with a thin layer of amorphous SiO2 had diameters of 30-70 nm and lengths of 4-10 mu m. The growth mechanism of the SiCNWs is proposed to be the combination of the chemical vapor deposition (CVD) method and the CNTs confined reaction method. According to the Kubelka-Munk plot, the band gap energy for the SiCNWs was 2.8 eV. The Mott-Schottky plot shows that the flat-band potential of the SiCNWs was -0.46V versus NHE and that the material exhibited n-type conductivity. The photoluminescence analysis of the SiCNWs revealed two wide bands of emission peaks centered at about 390 and 470 nm (CIE value: x=0.18, y=0.24). (C) 2008 Published by Elsevier B.V