Document Type

Article

Publication Date

10-1-2009

Publication Title

Surface Science

Abstract

Highly strained thin layers of GaSb/GaAs possess a (2 × 4) reconstruction at low Sb overpressures, and a (2 × 8) reconstruction at high Sb overpressures. While the atomic details of the Sb/GaAs-(2 × 4) are well known, the details of the (2 × 8) are not understood. In this paper, we use density functional theory to analyze possible (2 × 8) structures. Comparing scanning tunneling microscope images from both simulation and experiment and examining the relative energies of possible (2 × 8) structures, we show the α(2 × 8) and β(2 × 8) are the thermodynamically stable surface reconstructions for high Sb content films strained to the GaAs lattice parameter. The α and β(2 × 8) reconstructions are related to the GaAs-α2(2 × 4) and GaAs-β2(2 × 4) through the addition of 2 cations and 8 anions into the trench between adjacent (2 × 4) unit cells.

Comments

This work was performed in part at the US Department of Energy, Center for Integrated Nanotechnologies, at Los Alamos National Laboratory (Contract DE-AC52-06NA25396) and Sandia National Laboratories (Contract DE-AC04-94AL85000).

DOI

10.1016/j.susc.2009.07.044

Version

Postprint

Volume

603

Issue

19

Included in

Physics Commons

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