Morphological, structural and electrical characterization of nanostructured vanadium-tin mixed oxide thin films

Thin films made by a mixing of vanadium and tin oxides have been obtained by high vacuum thermal evaporation. A detailed, electrical, morphological and structural characterization has been performed on all deposited films. In particular, transmission electron microscopy observations allow us to confirm the realization of a thin film made by nanosized crystalline grains of vanadium oxide and tin oxide homogeneously arranged. The Hall effect measurements together with scanning tunnelling spectroscopy gives the surface density of electronic states and the electrical charge transport mechanism of our metal-oxide films as a function of surrounding atmosphere. In this way, the dopant effect of adsorbed oxygen on metal-oxide thin films was monitored. The obtained results allows us to conclude that the nanostructured vanadium-tin mixed oxide thin films is suitable for gas sensing applications. (C) 2004 Elsevier B.V. All rights reserved.