Electrostatic spray assisted vapour deposition of TiO2-based films

TiO2 is one of the best candidates for gas sensing because of its low cost, stable phase even at high temperature. higher gas sensitivity and comparable thermal expansion coefficient to alumina substrate. Further improvement in the performance can be achieved by addition of trivalent or pentavalent dopants. Recently, a novel electrostatic spray assisted vapour deposition (ESAVD) technique has been developed in our laboratory to prepare thin or thick films of various materials. This method offers many advantages over several conventional deposition techniques including a simple set-up.. inexpensive and nontoxic precursor. high deposition efficiency and easy control of the surface morphology of the deposited films and excellent control of stoichiometry. The possibility of morphology control is of particular interest for gas sensor application since the surface is primarily involved in the initial sensor/gas interaction. In this work, the structural and morphological characterization of TiO2-based films incorporated with Cr, Nb metal ions deposited by EASVD have been studied. Scanning electron microscopy (SEM) was used to analyze the microstructural and morphological properties. The X-my diffraction, (XRD) and Energy dispersion X-ray (EDX) analysis of SEM were employed to determine the crystal phase and film composition. X-ray photoelectron spectroscopy (XPS) was used to identify the surface chemical stoichiometry of the deposited films. (C) 2004 Elsevier B.V. All rights reserved.