Effect of an in-situ thermal annealing on the structural properties of self-assembled GaSb/GaAs quantum dots

Journal Article · 22 April 2016 · Applied Surface Science

DOI: https://doi.org/10.1016/j.apsusc.2016.04.131 · OSTI ID:1362248

Fernandez-Delgado, N. ^[1]; Herrera, M. ^[1]; Chisholm, M. F. ^[2]; Kamarudin, M. A. ^[3]; Zhuang, Q. D. ^[4]; Hayne, M. ^[4]; Molina, S. I. ^[1]

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1. Univ. of Cadiz (Spain)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
3. Lancaster Univ. (United Kingdom); Univ. Putra Malaysia (Malaysia)
4. Lancaster Univ. (United Kingdom)

The effect of the application of a thermal annealing on the structural properties of GaSb/GaAs quantum dots (QDs) is analyzed by aberration corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and electron energy loss spectroscopy (EELS). Our results show that the GaSb/GaAs QDs are more elongated after the annealing, and that the interfaces are less abrupt due to the Sb diffusion. We have also found a strong reduction in the misfit dislocation density with the annealing. The analysis by EELS of a threading dislocation has shown that the dislocation core is rich in Sb. In addition, the region of the GaAs substrate delimited by the threading dislocation is shown to be Sb-rich as well. An enhanced diffusion of Sb due to a mechanism assisted by the dislocation movement is discussed.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1362248
• Alternate ID(s): OSTI ID: 1416035
• Journal Information: Applied Surface Science, Vol. 395; ISSN 0169-4332
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English