Interplay of covalent bonding and correlation effects at molecule-metal contacts
We compare photoelectron spectra (PES) and theoretical densities-of-states of C-60/Al(111), C-60/Al(110) and C-60/Al(100). The splitting observed on all three surfaces is attributed to final state charging. This splitting can also be used to improve estimates of the charging energy U of adsorbed molecules and as a criterion for the existence of strong covalent bonding to the electrode. Au exhibits