Structural and cathodoluminescence assessment of V_2O_5 nanowires and nanotips grown by thermal deposition

Abstract

V_2O_5 nanostructures have been grown on 4H-SiC and Si substrates by a thermal deposition method without a catalyst. High aspect ratio nanowires with rectangular cross sections were grown on 4H-SiC. High-resolution transmission electron microscopy observations and cathodoluminescence (CL) spectroscopy measurements reveal the high crystal quality of the grown nanowires. Deposition on Si substrates leads to the growth of V_2O_5 platelets or rod-shaped crystals ending in arrays of parallel sharp nanotips with apex radius in the 50 nm range. A CL emission band observed centered at about 1.70 eV in spectra from these nanostructures is tentatively attributed to defect centers involving oxygen vacancies.