Effects of tungsten thickness and annealing temperature on the electrical properties of W-TiO2 thin films

TiO2 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-TiO2 hi-layer thin films. The crystal structure, morphology, and transmittance of these TiO2 and W-TiO2 bi-layer thin films were investigated. Amorphous, rutile, and anatase TiO2 phases were observed in the TiO2 and W-TiO2 bi-layer thin films. Tungsten thickness and annealing temperature had large effects on the transmittance of the W-TiO2 thin films. The W-TiO2 bi-layer thin films with a tungsten deposition time of 60 s were annealed at 200 degrees C-400 degrees C. The band gap energies of the TiO2 and the non-annealed and annealed W-TiO2 bi-layer thin films were evaluated using (alpha h nu)(1/2) versus energy plots, showing that tungsten thickness and annealing temperature had major effects on the transmittance and band gap energy of W-TiO2 bi-layer thin films. Crown Copyright (C) 2011 Published by Elsevier Ltd and Techna Group S.r.l. All rights reserved.