Electron relaxation in quantum dots by means of Auger processes

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 ${10}^{12}$ ${\mathrm{s}}^{\mathrm{-}1}$ for a plasma density of ${10}^{15}$ ${\mathrm{m}}^{\mathrm{-}2}$ 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.