Nanocrystalline SnO2 thin films prepared by anodization of sputtered Sn thin films

Abstract

Thin films of SnO2 are prepared by anodic oxidation of Sn on glass substrates. The surface topography of the anodic films is consistent with the original Sn films, indicating that the oxidation process primarily takes place perpendicularly along the Sn particles. As-prepared anodic SnO2 thin films possess an amorphous SnO2 phase at the surface, followed by an unoxidized thin layer of Sn between the SnO2 film and the substrate. With increasing annealing temperature, the residual Sn layer decreases until it disappears at 400 °C, and the amorphous SnO2 becomes nanocrystalline. The mobility of the as-prepared anodic SnO2 films is less than 0.1 cm2/(V s), but the annealed films have a mobility range of 1.6–2.2 cm2/(V s).