Electron relaxation in quantum dots by means of Auger processes.

Abstract

The present theoretical work deals with the relaxation of hot electrons in quantum dots by Coulomb scattering with an electron-hole plasma. A random-phase approximation is used which includes single-particle and collective-plasma excitations. We discuss the influence of the dot size, plasma density, and temperature. The resulting transition rates are of the order of ${10}^{12}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$ for a plasma density of ${10}^{15}$ ${\mathrm{m}}^{\mathrm{\ensuremath{-}}2}$ in ${\mathrm{In}}_{0.53}$${\mathrm{Ga}}_{0.47}$As/InP. In the presence of a dense electron-hole plasma, hot electrons can relax efficiently by Auger processes, even in small semiconductor quantum dots where the relaxation by phonon scattering is weak.