Hot electron transport in Ballistic Electron Emission spectroscopy:: Band structure effects and k∥-space currents

Using a Green's function approach, we investigate band structure effects in the BEEM current distribution in k(parallel to)-space. In the elastic limit, this formalism provides a "parameter free" solution of the BEEM problem. At low temperatures, and for thin metallic layers, the elastic approximation is enough to explain the experimental I(V) curves at low voltages. At higher voltages inelastic effects are approximately taken into account by introducing an effective RPA-electron lifetime, much in similarity with LEED theory. For thick films, however, additional damping mechanisms are required to obtain agreement with experiment.