Abstract
We show by first-principles density functional calculations that the adsorption of potassium on the platinum electrodes of a benzene dithiolate molecular wire junction will modify the energy-level alignments of the device. But near the Fermi energy, the energy levels, which correspond to sulfur orbitals, are quite inert to the work function change of the electrode due to a strong terminal atom/metal bonding. Our results demonstrate unambiguously that while the coadsorption of potassium on the electrodes may influence the conductance of a molecular device, it cannot change the conductance in a drastic way as the transmission peak near the Fermi level shifts only slightly with the introduction of potassium atoms.
- Received 31 May 2005
DOI:https://doi.org/10.1103/PhysRevB.72.125421
©2005 American Physical Society