Molecular-beam epitaxy of InSb/GaSb quantum dots

Journal Article · Fri Jun 15 04:00:00 EDT 2007 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2748872· OSTI ID:20979448

Deguffroy, N; Tasco, V; Baranov, A N; Tournie, E; Satpati, B; Trampert, A; Dunaevskii, M S; Titkov, A; Ramonda, M ^[1]

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1. Institut d'Electronique du Sud (IES), CC 067, Universite Montpellier 2, CNRS, UMR 5214, Place Eugene Bataillon, F-34095 Montpellier Cedex 5 (France)

We have investigated the molecular-beam epitaxy (MBE) of InSb nanostructures on (100) GaSb substrates. We show that MBE leads to a low density ({approx}1-3x10{sup 9} cm{sup -2}) of large islands even when varying the growth conditions on a wide range (substrate temperature {approx}370-450 deg. C, growth rate {approx}0.3-1.2 ML/s). Plastic relaxation takes place from the onset of island formation, regardless of the amount of InSb deposited after the two-dimensional to three-dimensional transition. These results show that In adatoms have a very long diffusion length on a Sb-terminated surface and that the energy for dislocation generation in InSb is low. This can be attributed to the low enthalpy of formation and low melting point of InSb. To circumvent this problem we have developed a MBE growth procedure based on the deposition of an amorphous InSb layer at low temperature followed by an annealing step to allow for reorganization to take place. This dramatic change of the growth conditions leads to the formation of small InSb quantum dots with a density in excess of 7x10{sup 10} cm{sup -2}. Uncapped quantum dots, however, are relaxed. In contrast, buried quantum dots are fully strained and emit near 3.5 {mu}m at room temperature. Our results show that although formerly similar the InSb/GaSb materials system behaves completely differently from the InAs/GaAs case study system.

• OSTI ID: 20979448
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 12 Vol. 101; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
CRYSTAL GROWTH
DEPOSITION
DIFFUSION
DIFFUSION LENGTH
DISLOCATIONS
FORMATION HEAT
GALLIUM ANTIMONIDES
GALLIUM ARSENIDES
INDIUM ANTIMONIDES
INDIUM ARSENIDES
LAYERS
MELTING POINTS
MOLECULAR BEAM EPITAXY
QUANTUM DOTS
SEMICONDUCTOR MATERIALS
SUBSTRATES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K