Structural and Optical Properties of V2O5 Thin Films Grown by PLD Technique

alpha -vanadium pentoxide (alpha-V2O5) thin films with the orthorhombic crystal structure were successfully grown on Si-substrates using pulsed laser deposition (PLD) technique with varying substrate temperatures. XRD spectra confirm the formation of orthorhombic V2O5 phase which is evident as the strongest peak at similar to 20.38 degrees. The films are apparently crystalline in nature, and the average crystallite size ranges between similar to 200 nm-similar to 400 as obtained from Scherrer's equation. FESEM image shows the films as compact nanostructured type displaying a globular (at 500 degrees C) or sheath like morphology (at 600 degrees C and 700 degrees C). AFM study shows that the average surface roughness of V2O5 films increases with increasing substrate temperature. UV-vis spectroscopy shows that the fundamental absorption edge has shifted to the red side (higher wavelength) with increasing temperature. Optical band gap values (E-g) decrease with increasing deposition temperature (at 700 degrees C, E-g similar to 2.08 eV).