Electronic transport on Au/Si structures: Electron-electron, electron-phonon, and band structure effects

Ballistic electron emission microscopy currents on Au/Si(111) and Au/Si(100) are analyzed using a Keldysh's formalism. The relative effect of the electron-electron interaction, quasielastic scattering (phonons), and band structure effects are shown to be relevant to interpret available experiments. The electron-phonon interaction can be introduced in the theory by computing an appropriate self-energy and solving Keldysh's equations self-consistently. The main effect of phonons is to create a more homogeneous current distribution in reciprocal espace, favoring injection on Si(111) over Si(100). Estimates for the electron-electron mean free path on Au are also obtained from this formalism.