C. Sarra-BournetP

Nitrogen-doped TiO2 thin films for biomedical and solar energy applications were deposited on glass and silicon wafer substrates using an Helicon-Assisted Reactive Sputtering Apparatus (HARES) in a mixture of Ar/O2/N2. The influence of the positive ion flux on the substrate and nitrogen partial pressure on the material properties (morphology, crystalline structure, chemical composition, optical properties) of TiOxNy has been investigated using a number of analytical techniques. The results show that a significant positive ion flux is required to obtain as-deposited crystalline TiO2 directly from the plasma process. Moreover, the presence of N2 in the discharge selectively hinders the formation of the crystalline rutile phase and promotes the growth of the nano-crystalline anatase phase. The role of Volmer-Weber growth in the formation of the nanostructure of these films is important and may provide some clues to the origin of the stress necessary for the formation of the various crystalline forms