Agradecimentos: The authors are indebted to Professor L. F. Zagonel (UNICAMP) for fundamental contributions along the development of this work. C. A. Piacenti is also acknowledged for technical assistance. This work was possible only thanks to the financial support provided by the Brazilian agencies FAPESP and CNPq. Ver menos

Er-doped TiO2-xNx films were grown by Ar+ ion-beam sputtering a Ti + Er target under different N-2 + O-2 high-purity atmospheres. The compositional-structural properties of the samples were investigated after thermal annealing the films up to 1000 degrees C under a flow of oxygen. Sample characterization included x-ray photoelectron spectroscopy, grazing incidence x-ray diffraction, Raman scattering, and photoluminescence experiments. According to the experimental data, both composition and atomic structure of the samples were very sensitive to the growth conditions and annealing temperature. In the as-deposited form, the N-rich TiO2-xNx films presented TiN crystallites and no photoluminescence. As the thermal treatments proceed, the films were transformed into TiO2 and Er3+-related light emission were observed in the visible and near-infrared ranges at room-temperature. Whereas the development of TiO2 occurred due to the insertion-diffusion of oxygen in the films, light emission originated because of optical bandgap widening and/or structural-chemical variations in the vicinity of the Er3+ ions. Finally, the photoluminescence results in the visible range suggested the potential of the present samples in producing an optically based temperature sensor in the similar to 150-500K range. Ver menos