The graphite valence band electronic structure: a combined core-valence-valence auger and valence band photoemission study

The Valence Band (VB) electronic structure of graphite is investigated via two VB probes, namely Core–Valence–Valence (CVV) Auger emission and VB photoemission, both induced by X-Ray (h=1486.6 eV) irradiation. The associated spectral structure is resolved by taking either the spectrum second derivative or the spectrum difference with respect to a smooth curve. Comparison between the two derived curves shows that both probes reproduce the VB Density Of States (DOS) in the upper VB region, while many body effects (Coulomb interaction between two final state holes of s-character) distort the CVV spectrum in the lower VB regio