Tungsten doped TiO 2 with enhanced photocatalytic and optoelectrical properties via aerosol assisted chemical vapor deposition

Abstract

Tungsten doped titanium dioxide films with both transparent conducting oxide (TCO) and photocatalytic properties were produced via aerosol-assisted chemical vapor deposition of titanium ethoxide and dopant concentrations of tungsten ethoxide at 500°C from a toluene solution. The films were anatase TiO 2, with good n-type electrical conductivities as determined via Hall effect measurements. The film doped with 2.25 at.% W showed the lowest resistivity at 0.034ωcm and respectable charge carrier mobility (14.9cm 3 /V.s) and concentration (×10 19 cm -3). XPS indicated the presence of both W 6+ and W 4+ in the TiO 2 matrix, with the substitutional doping of W 4+ inducing an expansion of the anatase unit cell as determined by XRD. The films also showed good photocatalytic activity under UV-light illumination, with degradation of resazurin redox dye at a higher rate than with undoped TiO 2.