Emergence of valence band structure in rare-gas clusters

The formation of electronic band structure by the valence-shell of Ar, Kr, and Xe clusters was studied for various cluster sizes using angle-resolved photoelectron spectroscopy. Different widths of the fine-structure components in the cluster spectra are attributed to a splitting of the outermost p 3 / 2 levels due to valence-orbital overlap between neighboring atoms. Photoelectron angular distributions from the cluster differ from the atomic cases and vary substantially for different bands. The evolution of the electronic structure with increasing cluster size emulates the changes of the valence band structure in the transition from a condensed-phase monolayer to the bulk.