Facile route to straight SnO2 nanowires and their optical properties

Rutile SnO2 nanowires were fabricated by a simple chemical vapor method using as-synthesized SnO2 nanoparticles as starting material. These nanowires with unusual [12-1] growth direction are very straight and uniform in diameter and length. Self-catalytic vapor-liquid-solid (VLS) mechanism should be responsible for the growth of the nanowires. The photoluminescence (PL) spectrum exhibits a wide yellow emission centered at 576 nm with a relatively small orange emission at 629 nm. The Raman spectrum exhibits four additional modes that are not allowed by rutile-type structure in first-order Raman-scattering at the zone center. The possible reasons for the unusual PL and Raman spectrum are proposed. (C) 2008 Elsevier B.V. All rights reserved.