Electronic properties of Fe-phthalocyanine (FePc) molecules in ultrathin films on Ag(111) have been investigated by scanning tunnelling spectroscopy and density functional calculations. Single FePc molecules show a broad signature of Fe d orbitals. However, in a twodimensional ordered superstructure spectroscopic contributions from individual dz2 and dxz/dyz orbitals are resolved. Calculations suggest that an increased molecule-surface distance in the superstructure and a change of the Ag(111) surface electronic structure cause the spectral changes, which are consistent with a partial electronic decoupling of the molecules from the substrate. A progressive evolution towards a gap around the Fermi level is observed for molecules atop the first and second molecular layer.
Financial support by the Deutsche Forschungsgemeinschaft through SFB 677 is acknowledged.
Electronic properties of Fe-phthalocyanine (FePc) molecules in ultrathin films on Ag(111) have been investigated by scanning tunnelling spectroscopy and density functional calculations. Single FePc molecules show a broad signature of Fe d orbitals. However, in a twodimensional ordered superstructure spectroscopic contributions from individual dz2 and dxz/dyz orbitals are resolved. Calculations suggest that an increased molecule-surface distance in the superstructure and a change of the Ag(111) surface electronic structure cause the spectral changes, which are consistent with a partial electronic decoupling of the molecules from the substrate. A progressive evolution towards a gap around the Fermi level is observed for molecules atop the first and second molecular layer.
Financial support by the Deutsche Forschungsgemeinschaft through SFB 677 is acknowledged.
