Reduction of concentration-induced luminescence quenching in Eu3+-doped nanoparticles embedded in silica

In this paper, high concentration (up to 40% of rare earth with respect to the metal oxides) Eu3+-doped ZrO2, Y2O3 and ZrO2–Y2O3 systems were prepared both as bulk material and as nanoparticles embedded in SiO2. The latter nanocomposites were obtained as a result of a thermal treatment at 1000 C of powder samples prepared by the sol–gel method. The combination of transmission electron microscopy (TEM), X-ray scattering (WAXS) and photoluminescence (PL) spectroscopy enabled us to obtain detailed information about morphology and composition of the rare earth-doped nanoparticles. In particular, for nanostructured samples, high luminescence has been observed in spite of a very high rare earth concentration in the active host.