Synthesis and Luminescence Properties of Ag 2 S and PbS Clusters in Zeolite A

Zeolite A provides a suitable environment to host Ag 2 S and PbS clusters, so that spectroscopic investigations on very small particles are possible. The Ag 2 S monomer is colorless and shows photoluminescence at 490 nm with a lifetime of 300 μs, while the absorption and luminescence of Ag 4 S 2 and larger clusters are red‐shifted. The properties of these Ag 2 S/zeolite A materials depend on the co‐cations. Results for Li + , Na + , K + , Rb + , Cs + , Mg 2+ , Ca 2+ , and Sr 2+ are reported. Excitation energy transfer between Ag 2 S and Ag 4 S 2 has been studied in materials containing Ca 2+ co‐cations. PbS particles can be prepared by the same method as Ag 2 S in the cavities of zeolite A. The PbS monomers obtained are yellow and show photoluminescence at 570 nm, with a lifetime of 700 ns.