Cerium and europium nanospecies in quartz glass: synthesis and spectral study

Abstract

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 5D0 → 7Fn manifolds (570–750 nm) of Eu3+ ions. The electric‐dipole 5D0 → 7F2 transition at 615 nm dominated in the Eu/SiO2 samples while the magnetic‐dipole transition 5D0 → 7F1 at 591 nm dominated in the CeEu/SiO2 double‐doped samples.