Valence band electronic structure of C60F18 and C60F36 studied by photoelectron spectroscopy

Photoemission spectra of solid fluorinated fullerenes C60Fx (x = 18, 36) were measured in comparison with parent C60 using synchrotron radiation (hν = 120 eV) providing the spectra in the density of states mode. Creation of the ion-like bonding of fluorine and disappearance of the π-states were observed to be a result of fluorination. Disappearance of the upper lying π-states was revealed to be a reason of the band gap widening upon fluorination.