ELECTRON RELAXATION BY INTERFACE-PHONON MODES IN QUANTUM DOTS

The role of interface phonon modes in electron relaxation processes in a GaAs quantum dot which is free standing in vacuum is investigated. For this, the electron scattering rates by interface phonons are calculated using an electron-phonon interaction Hamiltonian derived in the framework of the dielectric continuum model. By comparing the relaxation times to the radiative recombination lifetime of electrons and holes in their ground states, it is established that electron relaxation via interface phonon emission is significant in the radiative decay processes along with other relaxation mechanisms via longitudinal optical and longitudinal acoustic phonon emission. Different selection rules are obtained if the interface phonon mode involved in the scattering processes is symmetric or antisymmetric.