Photoemission spectroscopy shows that a very narrow peak and a broad distribution of density-of-states coexist near the Fermi level (EF) in K3C60, while the narrow peak at EF is not present in nonmetallic K4C60. This shows that K4C60, is a semiconductor with an energy gap at EF, contrary to the prediction from band structure calculations, and suggests that electron correlation is important in understanding the electronic structure of doped fullerenes, both metallic K3C60 and nonmetallic K4C60. The combination of photoemission, inverse photoemission and polarized oxygen-K-absorption in high Tc oxide superconductors shows that the hole-doping results in a similar electronic structure to that of doped fullerenes with the coexistence of a very narrow peak and a broad distribution of density-of-states near EF. We discuss the similarities and differences between doped fullerenes and high-Tc oxide superconductors based upon a comparison of their electronic structures.
ASJC Scopus subject areas
- 化学 (全般)