Europium-Doped Nanocomposite TiO_x:SiO_y Layers

The work presents TiO_x:SiO_y nanocomposite layers doped with Eu³⁺ ions. Layers were fabricated using the sol-gel method and dip-coating technique. It was shown that the viscosity of sols and the size of optical band gaps increase with increasing concentration of europium ions. Considering the quantum size effect, it was found that the presence of europium ions causes a weakening of the crystallization of titanium oxide. This means that the diameters of scattering centers are smaller, and the layer’s surfaces have lower roughness. In this way, the presence of europium ions in TiO_x:SiO_y waveguide layers contributes to reducing optical losses in the latter.