Europhys. Lett, 47 (6), pp. 701-707 (1999)
Substrate orientation dependence of island nucleation critical thickness in strained heterostructures
S. Sanguinetti 1, G. Chiantoni 1, E. Grilli 1, M. Guzzi 1, M.
A. Polimeni 2, A. Patané 2, L. Eaves 2 and P. C. Main 2
1 Istituto Nazionale per la Fisica della Materia and Dipartimento di
dei Materiali, Università di Milano Bicocca - Via Cozzi 53, 20125 Milano, Italy
2 School of Physics and Astronomy, University of Nottingham, University Park
Nottingham NG7 2RD, UK
(received 4 March 1999; accepted in final form 13 July 1999)
PACS. 68.35Rh - Phase transitions and critical phenomena.
PACS. 68.65 - Low-dimensional structures (superlattices, quantum well structures, multylayers): structure and nonelectronic properties.
PACS. 78.66Fd - III-V semiconductors.
The two-dimensional to three-dimensional transition in highly strained grown on high index (N11) substrates was investigated. The samples were characterised by photoluminescence measurements and atomic force microscopy. Controlled changes in the 2D/3D growth critical thickness have been observed by changing the substrate orientation. The results have been interpreted by means of an equilibrium model which takes into account the effects of substrate orientation. In-island strain relaxation, affected in a controlled way by substrate orientation, is found to play the major role in determining the critical thickness value.
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