Abstract
Nanocrystalline V2O5 films have been deposited on glass substrates at 300 degrees C substrate temperature using thermal evaporation technique and were subjected to thermal annealing at different temperatures 350, 400, and 550 degrees C. X-ray diffraction (XRD) spectra exhibit sharper and broader characteristic peaks respectively indicating the rearrangement of nanocrystallite phases with annealing temperatures. Other phases of vanadium oxides started emerging with the rise in annealing temperature and the sample converted completely to VO2 (B) phase at 550 degrees C annealing. FESEM images showed an increase in crystallite size with 350 and 400 degrees C annealing temperatures followed by a decrease in crystallite size for the sample annealed at 550 degrees C. Transmission spectra showed an initial redshift of the fundamental band edge with 350 and 400 degrees C while a blue shift for the sample annealed at 550 degrees C, which was in agreement with XRD and SEM results. The films exhibited smart window properties as well as nanorod growth at specific annealing temperatures. Apart from showing the PL and defect related peaks, PL studies also supported the observations made in the transmission spectra.