Fabrication and characterization of SiO2@SiC shell-core nanowire prepared by laser sintering

摘要

One-dimensional SiO2@SiC shell-core nanowire was fabricated on a SiC substrate without any catalyst using a laser sintering method. Based on a solid-liquid-vapor-solid (SLVS) in situ growth mechanism, the as-synthesized SiO2@SiC nanowires of about 60 nm diameter with a shell thickness of about 13 nm were grown. Varying the power density of laser sintering allowed the final SiC particle morphology to be controlled from grainy to whisker-like. High power density or high temperature benefited the nucleation probability of SiC whiskers. The isothermal oxidation test showed that the SiO2@SiC nanowires have good thermodynamic stability at high temperature. The photoluminescence (PL) property of SiO2@SiC nanowire was also investigated. The observed emission peaks were composed of an UV peak centered at 365 nm (3.40 eV) and a blue peak centered at 453 nm (2.74 eV). The theory behind the PL property and the growth mechanism of the SiO2@SiC nanowire were also discussed.