Ultraviolet photoelectron spectra of potassium dosed higher fullerenes

Ultraviolet photoelectron spectra of potassium dosed higher fullerenes are measured with a synchrotron radiation light source. Potassium dosing to hig her fullerenes brings a new structure between the spectral onset of pristin e fullerenes and the Fermi level. As the spectral edge of the new structure does not cross the Fermi level, potassium dosed higher fullerenes are not metallic but semiconductive. When the potassium is excessively dosed to the fullerenes, the lower binding energy structures above 5 eV become faint. I n contrast to this phenomenon, four distinct structures appear between 5 an d 14 eV.