X-ray absorption near edge structure investigation of vanadium-doped ZnO thin films

X-ray absorption near edge structure spectroscopy has been used to investigate the electronic and atomic structure of vanadium-doped ZnO thin films obtained by reactive plasma. The results show no sign of metallic clustering of V atoms, +4 oxidation state of V, 4-fold coordination of Zn in the films, and a secondary phase (possibly VO₂) formation at 15% V doping. O K edge spectra show V 3d-O 2p and Zn 4d-O 2p hybridization, and suggest that V⁴⁺ acts as electron donor that fills the σ* band.