INFLUENCE OF THE SUBSTRATE TEMPERATURE ON THE STRUCTURAL, OPTICAL AND THERMOELECTRIC PROPERTIES OF SPRAYED V2O5 THIN FILMS

Vanadium pentoxide (V2O5) thin films were deposited using the spray pyrolysis technique. An aqueous solution of ammonium vanadate with a 0.05 M concentration was used for depositing V2O5 thin films at three different substrate temperatures on glass substrates. The structural and optical characteristics of the V2O5 thin films were examined with X-ray diffraction (XRD) and double-beam UV-visible spectrophotometry. The X-ray diffraction study of the V2O5 thin films revealed a polycrystalline nature of the orthorhombic structure with the preferred orientation of (001). The crystallite size (d) was calculated from the (001) diffraction peak using the Debye-Scherrer formula. From the optical absorbance measurements, the optical band gap (E-g) was determined. A scanning electron microscope (SEM) was used to characterize the morphology of the films. Electrical measurements of the films indicated that the resistance decreases with an increase in the substrate temperature. From the thermoelectric measurements, the Seebeck coefficient was determined.