Breaking the phonon bottleneck in nanometer quantum dots: Role of Auger-like processes

Abstract

An Auger-like mechanism is described for the rapid transfer of the electron energy to the hole in the valence band via their Coulomb interaction in the nanometer size quantum dots. The relaxation time and its dependence on the nanocrystal energy band parameters and radius is obtained. A value of ∼ 2 ps has been calculated for the electron thermalization from the first excited to the ground state of spherical CdSe nanocrystals. Our results show that Auger-like processes remove the thermalization “phonon bottleneck” problem in nanometer quantum dots with level spacings greater than typical phonon energies.