Optical and electrical properties of vanadium pentoxide thin films

Electrochromic vanadium pentoxide (V2O5) thin films are prepared by the physical vapour deposition method using an electron beam gun. The transmission spectra of V2O5 thin films are measured and studied before and after UV irradiation. It is observed that the optical transmission minimum which occurs at 320 nm does not change with irradiation. The measurement of optical band gaps of V2O5 thin films before and after irradiation shows that the band gap increases due to irradiation. The electrical conductivity of the films as a function of time of irradiation is found to decrease rapidly and reaches a steady value with time when the irradiation is cut off. V2O5 thin films can be used for storing optical information and for development of optical memory switching devices. Activation energies for different thicknesses of thin films are reported.