Physical investigations on electron beam evaporated V2O5-MoO3 thin films

Thin films of the System (V2O5)(1-x)-(MoO3)(x) with 0 less than or equal to x less than or equal to 1 were prepared by electron-beam evaporation technique in an oxygen partial pressure of 2 x 10(-4) mbar onto silicon substrate maintained at temperature of 423 K. X-ray photoelectron spectroscopy and infrared data of these samples suggest that the film composition nearly approaches the nominal stoichiometry. The optical absorption studied in the wavelength range 300-1500 nm shows that the optical band gap increases with the increase of the MoO3 content in V2O5-MoO3 films. The electrical measurements exhibit a decrease of the conductivity with increasing MoO3 concentration. Results suggest the formation of the (V2O5)(1-x)-(MoO3)(x) solid solution. (C) 2001 Elsevier Science B.V. All rights reserved.