Effects of tungsten thickness and annealing temperature on the electrical properties of W–TiO 2 thin films

Abstract

TiO 2 thin films were prepared by RF magnetron sputtering onto glass substrates and tungsten was deposited onto these thin films (deposition time 15–60 s) to form W–TiO 2 bi-layer thin films. The crystal structure, morphology, and transmittance of these TiO 2 and W–TiO 2 bi-layer thin films were investigated. Amorphous, rutile, and anatase TiO 2 phases were observed in the TiO 2 and W–TiO 2 bi-layer thin films. Tungsten thickness and annealing temperature had large effects on the transmittance of the W–TiO 2 thin films. The W–TiO 2 bi-layer thin films with a tungsten deposition time of 60 s were annealed at 200 °C–400 °C. The band gap energies of the TiO 2 and the non-annealed and annealed W–TiO 2 bi-layer thin films were evaluated using ( αhν) 1/2 versus energy plots, showing that tungsten thickness and annealing temperature had major effects on the transmittance and band gap energy of W–TiO 2 bi-layer thin films.