Cerium and europium nanospecies in quartz glass: Synthesis and spectral study: Cer- und Europium-haltige Nanopartikel in Quarzglas: Synthese und spektroskopische Eigenschaften

Quartz glass doped with cerium (0.02-0.36 wt%) and europium (0.01-0.04 wt%) nanoparticles were prepared by a modified sol-gel method. Ultraviolet-visible optical absorption and steady-state photoluminescence excitation-emission techniques were applied for spectral characterization of samples. Absorption spectra for Ce/SiO2 samples showed two intense and broad bands of charge-transfer (CT) character at 240 and 300 nm that were attributed to the O2- -> Ce3+ and O2- -> Ce4+ transitions, respectively. For Eu/SiO2 and CeEu/SiO2 samples, CT bands O2- -> Eu3+ at 225 nm and non-resolved ones O2- -> Ce3+ at 245 nm were registered, respectively. Photoluminescence spectra of Ce/SiO2 samples showed the presence of Ce3+ ions emitting in the range of 413-438 nm caused by the 5d-4f transition. Photoluminescence spectra of Eu/SiO2 and CeEu/SiO2 samples featured the characteristic orange-red emission arising from D-5(0) -> F-7(n) manifolds (570-750 nm) of Eu3+ ions. The electric-dipole D-5(0) -> F-7(2) transition at 615 nm dominated in the Eu/SiO2 samples while the magnetic-dipole transition D-5(0) -> F-7(1) at 591 nm dominated in the CeEu/SiO2 double-doped samples.