Electronic structure of S-C6H5 self-assembled monolayers on Cu(1Â 1Â 1) and Au(1Â 1Â 1) substrates

We use first principles density functional theory to calculate the electronic structure of the phenylthiolate (S-C6H5) self-assembled monolayer (SAM) on Cu(1 1 1) and Au(1 1 1) substrates. We find significant lateral dispersion of the SAM molecular states and note its possible implications for transport properties of the molecular wire array. We calculate the two photon photoemission spectra and the work function of the SAM on Cu(1 1 1) and compare them with the available experimental data. Our results are used to discuss assignments of the observed spectral data and yield predictions for new electronic states due to the monolayer not yet accessed experimentally.