Self-aggregation of InAs quantum dots on (N11) GaAs substrates

We have fabricated InAs quantum dots on a wide range of substrate orientati ons with different coverages. We show that the range of GaAs substrate orie ntations capable of dot self-aggregation is quite wide and that substrate o rientation heavily affects ground state electronic properties. We report th e low temperature photoluminescence (PL) characterization of quantum dots g rown on GaAs with InAs deposition on eight surfaces intermediate between(10 0) and (111), namely (N11)A/B GaAs substrates, where N ranges from 2 to 5, and on a (100) substrate chosen for comparison purposes. For each substrate orientation, three different amounts of InAs were deposited. At 2 K, all t he samples show PL of evident quantum dot origin with an efficiency compara ble to that of samples grown on (100) substrates. PL spectra show inhomogen eously broadened, structured peaks in the 1.1-1.4 eV range. The quantum dot s grown at low InAs coverages deserve a special interest because of their n arrow (25 meV) emission linewidth. (C) 1998 Elsevier Science S.A. All right s reserved.