Size-dependent luminescence of small palladium particles

We report cathodoluminescence spectra of small Pd clusters of various size deposited on a thin, well-ordered oxide film. The size distribution of the deposited metal aggregates can be chosen and deliberately varied. The luminescence spectra vary characteristically as a function of the variation of particle size. The resonance energy at the highest luminescence energy with decreasing average particle size vary as expected for electronic states in a quantum confined metal particle. For an average aggregate size of 10 إ the luminescence is maximum.