Carbon 1 s studies of diamond(111): Surface shifts, hydrogenation, and electron escape lenaths

As probed by photoemission, the valence band emission spectra of diamond(lll) undergo reversible changes due to cycles of hydrogen adsorption and desorption. We report here carbon Is spectra from diamond(111) as a function of hydrogen exposure-annealing cycles and as a function of photon energy. We find an additional shoulder to lower binding energy in the C Is spectra of the hydrogen-free reconstructed 2 X 2/2 X1 surface and interpret this result as due to a chemical shift (0.95 ±0.1 eV) of the surface atoms. We analyze the data in terms of models for reconstruction and also derive the inelastic scattering length (escape length) of electrons in diamond over the kinetic energy range 25–1000 eV.