Electronic states of CuPc chains on the Au(110) surface

The electronic properties of Cu-phthalocyanine (CuPc) molecules flatlying along the channels of the Au(110) reconstructed surface have beeninvestigated by means of ultraviolet and x-ray photoelectronspectroscopy. The ordered chains give rise to a highly orderedsingle-layer structure with a (5x3) symmetry. Although from thecore-level analysis not any significant charge transfer between themolecules and the underlying Au surface is observed, the valence bandphotoemission data bring to light CuPc-induced features localized atthe interface. In particular, energy versus momentum dispersion of aninterface state reveals a bandwidth of about 90 meV along the enlargedAu channels, where the CuPc chains are formed, with a defined fivefoldsymmetry well fitting the CuPc intermolecular distance