Origin of disorder in self-ordered GaAs/AlGaAs quantum wires grown by OMVPE on V-grooved substrate

We have combined atomic force microscopy (AFM) and 2D + 1 Monte-Carlo simul ations to investigate the formation of local potential minima in self-order ed AlGaAs/GaAs V-groove quantum wires. In order to determine the origin of these potential fluctuations along the wire axis in the sub-micrometer rang e, we studied by AFM the morphology of V-grooved substrates at different st ages of processing and growth. Monte-Carlo simulations are used to study th e influence of the growth kinetics on the self-limiting profile in disorder ed V grooves. Our model evidences a re-entrant mechanism in which the sidew alls roughness induces monolayers thickness fluctuations along the wire axi s. The influence of the growth conditions on the quantum wire disorder is d iscussed. (C) 2000 Elsevier Science B.V. All rights reserved.