Effect of Annealing Temperature on Nanostructured WO3 Films on P-Si Substrate

Nanostructured WO3 films are prepared on p-Si substrate by facing target sputtering (FTS) method with sputtering pressure, 0.1 Pa and 200W. The sample is annealed at 850 C in air with 5 C/min. The as-deposited and annealed WO3 films have been characterized by the Grazing incidence X-ray diffractometer, Field emission electron microscopy, and Ultraviolet-visible spectrophotometer. The surface morphology of the WO3 films strongly depends on the annealing temperature. An average diameter of the WO3 nanorod is 5-6 μm long and 800 nm diameter. It is revealed from optical study that the band-gap energy of WO3 films is around 2.85 eV. The surface morphology of nanostructured WO3 films has been discussed with the increase of annealing temperature.