Series of silica-based glasses doped with antimony was synthesized to host luminescent silver clusters formed via Na+-Ag+ low-temperature ion exchange and heat treatment. Spectroscopic study reveals that increase in antimony concentration affects emission spectra, quantum yields, and fluorescence lifetimes. Photophysical processes rate constants, including radiative and nonradiative transitions and intersystem crossing, were estimated based on experimental spectroscopic characterization. Correlation between photophysical processes rate constants and increase in concentration of antimony was demonstrated.