First synthesis of vanadium oxide thin films by spray pyrolysis technique

Vanadium oxide thin films have been successfully deposited in the first time by spray pyrolysis technique at two substrate temperatures, 200 and 250 degreesC. In view of defining the optimal conditions for elaboration of vanadium oxide films, the as-deposited films were studied as a function of spray solution concentrations, using X-ray diffraction (XRD) and optical measurements. V2O5 and V4O9 polycrystalline films with an orthorhombic structure were easily obtained under the different spraying conditions. The AFM result indicates a grain size of approximately 50 and 80 nm for V2O5 and V4O9, respectively. The optical results show that the optical gap is equal to 2.44 eV for V2O5 and 2.34 eV for V4O9. (C) 2002 Elsevier Science B.V. All rights reserved.