Characterization of rutile N-doped TiO2 films prepared by RF magnetron sputtering

Rutile N-doped TiO2 thin films were grown by RF magnetron sputtering on amorphous and crystalline substrates at room temperature. The surface elemental analysis, investigated by X-ray photoelectron spectroscopy indicated that the nitrogen content of the films could be adjusted up to values as high as 4.1 at.%. As demonstrated by the X-ray diffraction data, the as-deposited films (100 - 200 nm thick) showed no detectable crystalline structure, while after successive annealing in air for one hour at 400 degrees C, 500 degrees C and 600 degrees C, the (110) rutile peaks occurred gradually as dominant features. The rutile phase in the films was confirmed by the band gap values of the deposited materials, which stabilized at 3.1 eV, for the thin films having 200 nm thicknesses.