Hot electron transport in Ballistic Electron Emission Spectroscopy: Band structure effects and -space currents

¹ Instituto de Ciencia de Materiales (CSIC ), Cantoblanco - E-28049 Madrid, Spain
² Lehrstuhl für Festkörperphysik, University of Erlangen-Nürnberg, Germany
³ Departamento de Física Teórica de la Materia Condensada Universidad Autonoma de Madrid - E-28049 Madrid, Spain
⁴ Institut für Theoretische Physik, Karl-Franzens-Universität Graz A-8010 Graz, Austria

Received: 27 April 1998
Accepted: 8 November 1998

Abstract

Using a Green's function approach, we investigate band structure effects in the BEEM current distribution in -space. In the elastic limit, this formalism provides a "para meter 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.