Effect of Annealing on Morphology and Photoluminescence of WO₃ Nanowires Deposited by Glancing Angle Deposition Techniques.

In this article, vertically aligned WO₃ nanowires were synthesized by employing the glancing angle deposition technique. The significant improvement in the crystallinity and surface morphology of the synthesized WO₃ nanowires were observed for 500 °C annealed samples and beyond that temperature it starts degrading. The X-ray diffraction confirmed the different phase transition after annealing. Increase in crystallite size from 68.93 nm to 77.41 nm was observed with the increase in annealing temperature from 300 °C to 500 °C. Upon 250 nm excitation, a broad blue emission aroused by near band edge emission is observed. Also, other emission peaks were observed due to the localized states of oxygen vacancies in the conduction band of WO₃. Fourier transform infrared result shows the bonding of WO₃ nanowires and intensity were greatly enhanced as the annealing temperature increases up to 500 °C. These enhancements in the properties could be applicable for the development of WO₃ based nanodevices.