Synthesis and Luminescent Properties of TiO<sub>2</sub> Materials Single and Triple Doped with Rare Earth Ions (Sm<sup>3+</sup> , Tb <sup>3+</sup> and Eu<sup> 3+</sup>)

Four types of titanium dioxide (TiO 2 ) materials doped with a single kind of rare earth ions Ln 3+ (Eu 3+ , Tb 3+ , or Sm 3+ ) and three rare earth ions (Eu 3+ , Tb 3+ , and Sm 3+ ) were synthesized by the sol-gel method. The compositions, structures, and photophysical properties of these compounds were tested. The structure of the rare earth ion-doped TiO 2 samples was characterized by X-ray powder diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). Optical absorption and fluorescence information was obtained using UV-Vis spectroscopy and fluorescence spectroscopy. The surface morphology of rare earth ion-doped TiO 2 materials was observed using scanning electron microscopy (SEM). To further explore the photoluminescent properties of rare earth-doped TiO 2 materials for practical applications, small-scale LED light-emitting devices were fabricated.