Controlled Growth and Characterization of Tungsten Oxide Nanowires Using Thermal Evaporation of WO₃ Powder

Tungsten oxide (WO 3 ) nanowires were prepared on a tungsten (W) substrate by thermal evaporation of WO 3 powder at elevated temperature in a tube furnace. The morphology, structure, composition, and chemical state of the prepared nanowires were characterized by SEM, EDX, TEM, XRD, Raman spectroscopic, and XPS measurements. The nanowires grown using WO 3 powder were found to have uniform morphology with a high density and a crystalline structure consistent with monoclinic WO 3 . The field-emission measurements showed that the prepared nanowires have a turn-on field of 4.8 V/μm. The role of WO 3 powder in the growth of high-density nanowires has been discussed by comparing the above results with those of nanowires grown without using WO 3 powder and also on a different substrate. Also, the effects of growth temperature on the chemical binding states and product morphology of the nanowires were investigated.