The Role of Thermally Activated Quenching and Energy Migration in Luminescence of Silver Clusters in Glasses

Luminescent silver clusters stabilized in different hosts represent an important class of new luminophores with numerous potential applications. Nevertheless, there are a lot of open questions regarding the emission mechanism of the clusters. In this work, luminescence properties of silver clusters in a silica-based glass were analyzed by using steady-state and time-resolved spectroscopy. The obtained results suggest that deactivation of cluster excited states does not include cluster interaction and should be treated on a single cluster scale. The temperature change of cluster emission confirms the mechanism of temperature-activated intersystem crossing as a way of excited singlet state deactivation. The study of fluorescence temperature dependence reveals the features attributed to the existence of two different temperature-activated quenching processes.