AUGER CARRIER RELAXATION IN SELF-ASSEMBLED QUANTUM DOTS BY COLLISIONSWITH 2-DIMENSIONAL CARRIERS

Carrier relaxation in self-assembled quantum dots due to Coulomb inter action with two dimensional (2D) carriers is studied theoretically. Au ger coefficients for carrier relaxation rates are calculated in the di pole approximation for Coulomb interaction. The dipole approximation a llows one to derive selection rules for Auger relaxation in a cylindri cal quantum dot, and to describe a general picture of Auger relaxation via energy levels in self-assembled quantum dots. A numerical example for InAs/GaAs self-assembled quantum dots demonstrates that the Auger effect may lead to relaxation times in the order of 1-10 ps at 2D car rier densities of 10(11)-10(12) cm(-2). This result demonstrates the p ossibility of fast carrier relaxation in quantum dots if the carrier d ensity in the surrounding barrier is sufficiently high. Analytical for mulas for Auger coefficients are derived for moderate temperatures of the 2D carriers. (C) 1997 American Institute of Physics.