GaAs/AlGaAs quantum dots by implantation induced intermixing

Abstract

By implantation induced intermixing we have realized GaAs/AlGaAs quantum dots with diameters down to 70 nm. In low‐temperature photoluminescence an increasing shift to higher energies, up to 7 meV, with decreasing dot diameter is observed. From a simple model we conclude that a very steep lateral potential has been achieved and that the shift is partly due to the radial confinement. All dot structures show a high luminescence intensity and in the time integrated measurements no indication for a strong reduction of the energy relaxation is observed. This could be attributed to the measured carrier capture from the lateral barrier into the dots and by the shape of the radial potential which determines the energy levels in the dots.