IMPORTANCE OF SURFACE EFFECTS AND DYNAMICAL CORE-HOLE EFFECTS IN AUGER SPECTRA OF METALS AND SEMICONDUCTORS

Abstract
Auger CVV spectra of sp-bonded materials are generally believed to be well described by one-electron theory in the bulk. We here perform detailed calculations on several simple metals and on silicon and obtain results which differ markedly from experiments. To explain these discrepancies we investigate effects of the surface and dynamical effects of the sudden disappearance of the core hole in the final state. To study core-hole effects we solve Mahan-Nozières-DeDominicis (MND) model numerically over the entire band. The core-hole potential and other parameters in the MND model are determined by self-consistent calculations on systems with a core-hole impurity. To study surface and mean free path effects we perform slab calculations in the case of silicon, whereas we for the metals use a simpler infinite barrier model in which the valence states near the surface are constructed from Bloch states in a simple way. In all cases investigated either the effects of the surface or the effects of the core hole give important modifications and a much improved agreement with experiments.