Comparative high-energy resolution (ΔE ∼ 30 meV) photoemission spectroscopy has been performed for CsxC60 and KxC60 to study the difference and similarity in the electronic structure near the Fermi level (EF) between the superconducting and the non-superconducting alkali-doped C60. It was found that CsxC60 (0≤x≤6) is a semiconductor or an insulator in the whole composition range except for 0<x≤1 where the Cs doped C60 appears to be metallic with a finite density of states at EF. This shows a sharp contrast with the case of KxC60 which exhibits a relatively large density of states at EF in the composition of 0<x<4 with the largest intensity around x = 3.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering