PHOTOELECTRON-SPECTRA OF HIGHER FULLERENES AND THEIR POTASSIUM COMPLEXES

Ultraviolet photoelectron spectra of higher fullerenes, C-76, C-78, C- 82, C-84 and C-96 have been measured with a synchrotron radiation ligh t source. When the number of the carbon atoms increases, the spectral onset moves toward the Fermi level. The spectral structures above 5 eV are characteristic to each fullerene. The structures below 5 eV resem ble, which indicates the analogous electronic structures of the fuller ene carbon cages. When potassium is dosed onto higher fullerenes, a st ructure appears between the spectral onset and the Fermi level. This i s the result of the transfer of the K 4s election to the lowest unoccu pied molecular orbital of higher fullerenes. The spectral onset of pot assium dosed higher fullerenes does not cross the Fermi level at any p otassium content, which suggests their semiconductive nature.