Photosensitization of europium ions by silver clusters in zeolite

Photosensitization of europium (Eu) ions by silver (Ag) clusters was achieved by simultaneously doping Eu and Ag in zeolite cages. The photoluminescence (PL) due to the 5D0→7F2 transition of Eu ions at 613 nm is significantly increased by the presence of Ag clusters. The excitation wavelength dependence of the PL intensity coincided well with the absorption spectrum of Ag clusters, indicating that Eu ions are excited by the energy transfer from Ag clusters.