Molecule-metal interaction of pentacene on copper vicinal surfaces

A combined X-ray photoemission and absorption spectroscopy study of the adsorption of pentacene layers grown on the Cu(1 1 9) vicinal surface is presented. A significant interaction between the π molecular orbitals delocalized on the aromatic rings and the underlying copper substrate is evicted by C 1s core levels manifold peaks at the interface. Adsorption geometry with pentacene molecules almost flat-lying along the Cu terraces is confirmed by the polarization dependence of the C 1s absorption features.