Thin Solid Films, Vol.336, No.1-2, 9-12, 1998
Self-aggregation of InAs quantum dots on (N11) GaAs substrates
We have fabricated InAs quantum dots on a wide range of substrate orientations with different coverages. We show that the range of GaAs substrate orientations capable of dot self-aggregation is quite wide and that substrate orientation heavily affects ground state electronic properties. We report the low temperature photoluminescence (PL) characterization of quantum dots grown on GaAs with InAs deposition on eight surfaces intermediate between(100) 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 the samples show PL of evident quantum dot origin with an efficiency comparable to that of samples grown on (100) substrates. PL spectra show inhomogeneously broadened, structured peaks in the 1.1-1.4 eV range. The quantum dots grown at low InAs coverages deserve a special interest because of their narrow (25 meV) emission linewidth.
Keywords:ORGANIZED GROWTH