Impact of top metal electrodes on current conduction in WO3 thin films

Abstract Using radio-frequency (rf) sputtering technique tungsten oxide (WO 3 ) thin films (∼150 nm) were deposited in a gas mixture of Ar and O 2 at 10 mTorr pressure on indium tin oxide (ITO) and corning glass substrates. The films were annealed at 400 °C. Structural and optical properties of films were studied. Metal–insulator–metal (MIM) structure was made by depositing metal electrode (Ag, Al, Au) on the prepared WO 3 thin films (on ITO substrate) using thermal evaporation technique. Electrical properties of the MIM structure were studied by plotting current versus voltage ( I – V ) curves for Ag, Al and Au metal electrodes. Current conduction mechanism in WO 3 film was determined by plotting and fitting I – V data in different equations of current mechanisms.