PHOTOEMISSION-STUDY OF K-DOPED AND SC-DOPED C84

The electronic structure of solid C84 With doping of K or Sc metal was studied by ultraviolet photoemission spectroscopy. Successive filling of the LUMO (lowest unoccupied molecular orbital), LUMO+1, and LUMO+2 bands by electrons donated from doped K atoms was clearly observed in K-doped C84. In the case of Sc-doped one, no clear successive filling of unoccupied bands was observed although new electronic states appea r between the HOMO (highest occupied molecular orbital) band and the F ermi level with doping. In either of K- and Sc-doped solid C84, no cle ar Fermi-edge cutoff indicative of its metallic nature was observed in the spectrum.