Data of Depth-Resolved Dielectric Function of Oxygen-Deficient WO3-x thin films by RF-sputtering and post-growth thermal annealing in air

Variable Angle Spectroscopic Ellispsometry (VASE) has been used to measure the dispersion of complex dielectric function of tungsten oxide thin films, deposited by non-reactive RF magnetron sputtering at room temperature and thermally annealed post-growth, over the spectral range 350nm-1700nm . Graded fitting models have been developed, for best fitting of the experimental data. Data here collected regard the real and imaginary parts of the dielectric function, as extracted from VASE modeling, for the as-deposited films and for films annealed at 400°C and at 500°C. One Excel file relates to As-deposited films and films less thick than 70nm, which do not require model grading. In that case, the data are averaged in thickness. Thicker films instead require a graded model and values for the dielectric functions are given at different depths in the film. From the data here provided, real and imaginary parts of the refractive index can be computed.