ANGULAR AND ENERGY-DISTRIBUTION OF AUGER AND PHOTOELECTRONS ESCAPING FROM NONCRYSTALLINE SOLID-SURFACES

The angular and energy distribution of Auger and photoelectrons emitted from non-crystalline solids has been studied by transport theory, in the framework of the transport approximation. Expressions for the pathlength distribution as well as for the angular and energy distribution have been derived. It has been shown, for the first time, that the relative contribution of the inelastic background to the spectrum depends on the emission angle. A background subtraction procedure for homogeneous solids which accounts for this emission angle dependence has been developed and tested. It was found that the proposed method consistently removes the inelastic background over the entire angular range. All theoretical results have been compared (on the absolute scale) with Monte Carlo calculations based on the more realistic Mott cross sections for elastic scattering. Very good agreement between theory and the model calculations has been found. This result provides further evidence for the validity of the transport approximation and for the so-called generalized radiative field similarity principle which states that the exact shape of the elastic scattering cross section does not significantly influence the emission characteristics provided the initial source angular distribution is sufficiently smooth.