PENNING IONIZATION ELECTRON-SPECTROSCOPY OF IRON PHTHALOCYANINE THIN-FILMS - STUDY OF ELECTRONIC-STRUCTURE FROM LOCAL ELECTRON-DISTRIBUTION OF MOLECULAR-ORBITALS

Penning ionization electron spectra (PIES) and ultraviolet photoelectron spectra (UPS) were measured for two kinds of ultrathin films of iron phthalocyanine with different orientation of surface molecules. The local electron distribution of molecular orbitals (MO) at the different parts of the molecule was reflected in the PIES. From this the character of MOs responsible for each band in the PIES and UPS was revealed. The so-called iron 3d bands were assigned to 3d⊥ (dxz, dyz, dz2 )-like MOs. The IP values for π MOs were found to be less than ∼12 eV in the solid phase. It was concluded that the type of MOs probed by PIES can be selected if the orientation of molecules is controlled appropriately, which will be of great help to elucidate the electronic structure of complex molecules. © 1990 American Institute of Physics.