Formation and atomic structure of GaSb nanostructures in GaAs studied by cross-sectional scanning tunneling microscopy

• Published in: Physica. E, Low-dimensional systems & nanostructures Low-dimensional systems & nanostructures, 2005-02, Vol.26 (1), p.231-235
• Main Authors: Timm, R., Grabowski, J., Eisele, H., Lenz, A., Becker, S.K., Müller-Kirsch, L., Pötschke, K., Pohl, U.W., Bimberg, D., Dähne, M.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; GaAs; GaSb; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; MOCVD; Physics; Quantum dots; Quantum wells; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); XSTM
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2004.08.058

GaSb nanostructures in GaAs, grown by metalorganic chemical vapor deposition, were studied with cross-sectional scanning tunneling microscopy. Three different samples were examined, containing a thin quantum well, a quantum well near the critical thickness for dot formation, and finally self-organized quantum dots with base lengths of 5–8 nm and heights of about 2 nm. The dots are intermixed with a GaSb content between 60% and 100%. Also small 3D and 2D islands were observed, possibly representing quantum dots in an early growth stage and quantum dot precursors. All GaSb layers exhibit gaps, which are indications of an island-like growth mode during epitaxy.