Influence of different V-grooved GaAs substrates on the geometrical shape of InGaAs/GaAs quantum wires

The structure of InGaAs/GaAs quantum wires (QWRs) grown on V-grooved GaAs substrates by low pressure metalorganic vapor phase epitaxy was studied by conventional and high resolution transmission electron microscopy. We show that, by growing the structure on grooves with (3 1 1)A-like and (1 1 1)A-like oriented facets, the quantum wire profile can be changed from a constant thickness bent layer to a strongly tapered quantum wire of crescent shape. Highly uniform arrays of vertically stacked wires with a narrow size distribution along the growth direction have been obtained for both structures.