The electronic structure of K6C60 studied by soft X-ray spectroscopy

The electronic structure of C-60 and potassium doped C-60 has been studied by soft-X-ray absorption and emission spectroscopies. The C K alpha emissio n spectrum of doped C-60 shows a resolved filled lowest unoccupied molecula r orbitals (LUMO) (t(1 alpha))-derived valence band. The intensity ratio of the highest occupied molecular orbitals (HOMO)-derived band to LUMO-derive d band is 2, indicating that a K6C60 phase is forming the potassium doped C -60 film. Small variations with excitation energy in the spectral shape com pared to solid C-60 suggest that resonant inelastic X-ray scattering become s less prominent due to the formation of solid-state system upon potassium doping. (C) 2001 Elsevier Science BN; All rights reserved.