Structural and cathodoluminescence assessment of V2O5 nanowires and nanotips grown by thermal deposition

V2O5 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 V2O5 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.