Photoluminescence properties of Tb3+ and Eu3+ ions hosted in TiO2 matrix

Photoluminescence (PL) properties of TiO2:Eu and TiO2:Tb films growth by sol-gel on glass substrates are reported. For TiO2:Eu films the spectral lines are due to the 5D0→7Fj Eu3+ electronic levels and its intensity increases as the content of Eu in the films. For the TiO2:Tb films not clear spectral lines coming from the Tb3+ electronic structure is detected, just broad bands due to the Tb3+ and TiO2 defects levels were observed. The slight signal observed from Tb3+ electronic levels, for the Tb-doped films, is removed as soon as the samples are annealed at 600 deg. C. The results show that the Eu3+ and Tb3+ are incorporated in different crystallographic sites in the TiO2 amorphous matrix