Energy dissipation of electrons at a p-type GaAs(110) surface

TL;DR

This study investigates how electrons injected into p-type GaAs(110) surfaces lose energy, revealing that surface states significantly influence non-radiative recombination and luminescence suppression.

Contribution

It provides a quantitative analysis combining first principles calculations and rate equations to elucidate electron energy dissipation mechanisms at the GaAs surface.

Findings

Surface states near Ga atoms reduce luminescence intensity.

Fast surface scattering suppresses bulk recombination.

Electrons mainly undergo non-radiative surface recombination.

Abstract

Electron injection from the tip of a scanning tunneling microscope into a p-type GaAs(110) surface have been used to induce luminescence in the bulk. Atomically-resolved photon maps revealed significant reduction of luminescence intensity at surface states localized near Ga atoms. Quantitative analysis based on the first principles calculation and a rate equation approach was performed to describe overall energy dissipation processes of the incident tunneling electrons. Our study shows that the recombination processes in the bulk electronic states are suppressed by the fast electron scattering at the surface, and the electrons dominantly undergo non-radiative recombination through the surface states.