Potassium doped Co phthalocyanine films: Charge transfer to the metal center and the ligand ring

The electronic properties of potassium doped cobalt phthalocyanine (CoPc) films have been investigated using near-edge X-ray absorption fine structure measurements. Our results demonstrate that charge transfer to the CoPc molecules changes both the valence of the phthalocyanine ring as well as that of the central Co ion. The first electron transferred to the molecule occupies a Co 3d state, which is connected to a change of the magnetic moment of the molecule.