Growth of ordered bithiophene layers on the p(2 × 1)O reconstructed Cu(1 1 0) surface

Submonolayer to multilayer coverages of bithiophene on the clean Cu(1 1 0) and the Cu(1 1 0)–p(2 × 1)O reconstructed surface have been investigated comparatively with thermal desorption spectroscopy, angle resolved ultraviolet photoemission spectroscopy (ARUPS) and near edge X-ray absorption fine structure spectroscopy. On the clean Cu(1 1 0) substrate the bithiophene monolayer is strongly bound via the π-orbitals and flat lying. After the completion of the wetting layer, further growth occurs in islands with no evidence for a preferred molecular orientation or order. In contrast, on the oxygen reconstructed surface the wetting layer formed has a weaker interaction with the substrate and in this monolayer the molecular plane is tilted with respect to the surface. For the multilayer film on the Cu(1 1 0)–p(2 × 1)O reconstructed surface the ARUPS displays a distinct azimuthal anisotropy. This is suggested to arise from a template effect of the reconstruction.