Physical properties characterization ofW03 films grown by hot-filatnent metal oxide deposition

Abstract

W03 is grown by hot-filament metal oxide deposition (HFMOD) technique under atmospheric pressure and an oxygen atmosphere. By X-ray diffraction obtains thatW03 presents mainly monoclinic crystalline phase. The chemical stoichiometry is obtained by X-ray Photoelectron Spectroscopy (XPS ). The IR spec­ trum of the as-grown W03 presents broad peaks in the range of 1100 to 3600 cm- 1 • A broad band in the 2200 to 3600cm- 1 region and the peaks sited at 1645 and 1432cm-1 are well resolved, which are originated from moisture and are assigned to v(OH) and o(OH) modes of adsorbed water and the corre­ sponding tungsten oxide vibrations are in infrared region from 400 to 1453 cm-1 and around 3492 cm-1 , which correspond to tungsten-oxygen ( W-0) stretching, bending and lattice modes. The Raman spec­ trum shows intense peaks at 801,710,262 and 61 cm-1 that are typical Raman peaks of crystalline W03 (m-phase) that correspond to stretching vibrations of the bridging oxygen, which are assigned to W-0 stretching (v) and W-0 bending (o) modes, respectively. By transmittance measurements obtains that the W03 band gap can be varied from 2.92 to 3.13 eV in the investigated annealing temperature range.