X-Ray-Photoelectron Spectrum of Diamond

The x-ray-photoelectron spectrum of powdered diamond samples in the binding-energy range -15 to 1050 eV is reported. The major features of the spectrum are the C $1s$ and surface contaminant $\mathrm{O}1s$ peaks, the carbon and oxygen Auger transitions, and diamond's valence-region structure. Plasma-resonance excitations are identified in the inelastic tail of the C $1s$ peak. The valence-region spectrum is analyzed and corrected for the presence of what is interpreted to be extrinsic structure. The corrected spectrum maps out primarily the $s$-like states in diamond's density of states, and indicates a valence-band width of 21 eV.