Unoccupied states of individual silver clusters and chains on Ag(111)

TL;DR

This study investigates the unoccupied electronic states of silver clusters and chains on Ag(111), revealing size-dependent spectral shifts and the influence of cluster geometry through experimental STM imaging and DFT calculations.

Contribution

It provides new insights into the unoccupied states of silver nanostructures and correlates experimental observations with theoretical calculations.

Findings

Unoccupied resonances shift toward the Fermi level with increasing cluster size.

Linear assemblies show higher resonance energies than compact ones of similar size.

DFT calculations successfully reproduce the experimental spectral features.

Abstract

Size-selected silver clusters on Ag(111) were fabricated with the tip of a scanning tunneling microscope. Unoccupied electron resonances give rise to image contrast and spectral features which shift toward the Fermi level with increasing cluster size. Linear assemblies exhibit higher resonance energies than equally sized compact assemblies. Density functional theory calculations reproduce the observed energies and enable an assignment of the resonances to hybridized atomic 5s and 5p orbitals with silver substrate states.