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

TL;DR

This paper uses a Green's function approach to analyze band structure effects and k-space currents in Ballistic Electron Emission Spectroscopy, providing insights into elastic and inelastic electron transport mechanisms.

Contribution

It introduces a parameter-free Green's function formalism for BEEM, accounting for elastic and inelastic effects, and compares theoretical predictions with experimental data.

Findings

Elastic approximation explains low-voltage I(V) curves for thin layers.

Inelastic effects are modeled with an effective RPA-electron lifetime.

Thick films require additional damping mechanisms for accurate modeling.

Abstract

Using a Green's function approach, we investigate band structure effects in the BEEM current distribution in reciprocal space. In the elastic limit, this formalism provides a 'parameter free' solution to 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.