Abstract
The plasmonic behavior of size-selected supported silver clusters is studied by surface second harmonic generation spectroscopy for the first time. A blue shift of ∼0.2 eV in the plasmon resonance is observed with decreasing cluster size from Ag55 to Ag9. In addition to the general blue shift, a nonscalable size-dependence is also observed in plasmonic behavior of Ag nanoclusters, which is attributed to varying structural properties of the clusters. The results are in quantitative agreement with a hybrid theoretical model based on Mie theory and the existing DFT calculations.