Quenching of silver clusters luminescence by Eu(III) and Sm(III) ions in ion-exchanged layers of silica-based glass

Abstract

Series of silica-based glasses doped with La₂O₃, Eu₂O₃, and Sm₂O₃ was synthesized to host luminescent silver clusters formed via Na⁺-Ag⁺ ion exchange and heat treatment. Photoluminescence spectra of the glasses with Eu³⁺ or Sm³⁺ ions consist of broad white emission from silver clusters and characteristic bands of rare-earth ions. Energy transfer between silver clusters and Eu³⁺ or Sm³⁺ ions was studied by controlling luminescence quantum yield and lifetime of silver clusters. Rare-earth doping of the studied glass decreases the amount of forming silver clusters, therefore, the quenching efficiency of Eu³⁺ and Sm³⁺ ions was calculated in comparison to the glasses doped by La³⁺. It was shown that quantum yield of cluster luminescence decreases faster than the fluorescence and phosphorescence lifetime in the presence of Eu³⁺ or Sm³⁺ ions. Difference in quenching efficiency of luminescence quantum yield and emission lifetime of silver clusters was explained by the coexisting of two different mechanisms of quenching.