Spectroscopic evidence of NOx formation and band-gap narrowing in N-doped TiO2 films grown by pulsed magnetron sputtering

► Highly-doped TiO2:N films have been grown by reactive pulsed magnetron sputtering. ► The electronic structure has been assessed by XANES and high-resolution XPS. ► N incorporation favors the formation of anatase structures and narrows the band-gap. ► The spectroscopic data evidence the role of N interstitials in the form of NOx complexes.