Host-Sensitized Luminescence of Nd3+ and Sm3+ Ions Incorporated in Anatase Titania Nanocrystals

A sol-gel solvothermal method was introduced to incorporate Nd3+ and Sm3+ ions into TiO2 nanoparticles. Intense and well-resolved emission lines from Nd3+ or Sm3+ ions were realized upon excitation above the TiO2 bandgap at room temperature. The sensitized emissions of Nd3+ or Sm3+ were found to be much more efficient than a direct excitation of lanthanide ions (Ln(3+)). Multiple site emissions of Nd3+ and Sm3+ were detected by means of site-selective spectroscopy at 10 K. Moreover, a possible host-to-Ln(3+) sensitization mechanism was proposed.