Digital.CSIC > Ciencia y Tecnologías Físicas > Instituto de Microelectrónica de Madrid (IMM-CNM) > (IMM-CNM) Artículos >




Closed Access item Morphological evolution of InAs/InP quantum wires through aberration-corrected scanning transmission electron microscopy

Authors:Sales, D. L.
Varela, M.
Pennycook, S. J.
Galindo, P. L.
González, Luisa
González, Yolanda
Fuster, David
Molina, Sergio I.
Keywords:Quantum wires, Thin films, Transmission electron microscopy
Issue Date:21-Jul-2010
Publisher:Institute of Physics Publishing
Citation:Nanotechnology 21(32): 325706 (2010)
Abstract:Evolution of the size, shape and composition of self-assembled InAs/InP quantum wires through the Stranski–Krastanov transition has been determined by aberration-corrected Z-contrast imaging. High resolution compositional maps of the wires in the initial, intermediate and final formation stages are presented. (001) is the main facet at their very initial stage of formation, which is gradually reduced in favour of {114} or {118}, ending with the formation of mature quantum wires with {114} facets. Significant changes in wire dimensions are measured when varying slightly the amount of InAs deposited. These results are used as input parameters to build three-dimensional models that allow calculation of the strain energy during the quantum wire formation process. The observed morphological evolution is explained in terms of the calculated elastic energy changes at the growth front. Regions of the wetting layer close to the nanostructure perimeters have higher strain energy, causing migration of As atoms towards the quantum wire terraces, where the structure is partially relaxed; the thickness of the wetting layer is reduced in these zones and the island height increases until the (001) facet is removed.
Publisher version (URL):http://dx.doi.org/10.1088/0957-4484/21/32/325706
Appears in Collections:(IMM-CNM) Artículos

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.