ELECTRONIC INVESTIGATION OF SELF-ORGANIZED INAS QUANTUM DOTS

Deep Level Transient Spectroscopy (DLTS) has been applied to investiga te the electronic properties of self-organized InAs quantum dots. The energies of electronic ground states of 2.5ML and 1.7ML InAs quantum d ots (QDs) with respect to the conduction band of bulk GaAs are about 0 .21 eV and 0.09 eV, respectively. We have found that QDs capture elect rons by lattice relaxation through a multi-phonon emission process. Th e samples are QDs embedded in superlattices with or without a 500 Angs trom GaAs spacing layer between every ten periods of a couple of GaAs and InAs layers. The result shows that the density of dislocations in the samples with spacer layers is much lower than in the samples witho ut the spacer layers.