Optical absorption studies on (V2O5)1-x-(MoO3)x thin films

Thin films of (V2O5)(1-x)-(MoO3)(x) (0 less than or equal to x less than or equal to 1)were prepared by the electron beam evaporation technique in an oxygen partial pressure of 2 x 10(-4) mbar and at a substrate temperature of 423 K. The optical absorption studies in the wavelength range 300-1500 nm suggested the increase of the optical bandgap with increasing x and showed a curvilinear behaviour. The width of the localized states E-e estimated from the slopes of ln alpha vs hnu plots of (V2O5)(1-x)-(MoO3)(x) films were in the range 0.42-0.35 eV The electrical conductivity decreased with the increase of composition x. (C) 2002 Published by Elsevier Science B.V.