Droplet epitaxy of GaAs quantum dots on (001), vicinal (001), (110), and (311)A GaAs

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Erscheinungsjahr:
2009
Medientyp:
Text
Schlagworte:
  • A1. Atomic force microscopy
  • A1. Diffusion
  • A1. Low-dimensional structures
  • A3. Molecular beam epitaxy
  • B2. Semiconducting III-V materials
Beschreibung:
  • We study the formation of GaAs quantum dots (QDs) by droplet epitaxy on various GaAs surfaces. The fabrication process consists of two steps. First, liquid Ga droplets are grown in a Volmer-Weber-like mode. This is followed by crystallization under As pressure. We demonstrate fabrication of droplet epitaxial GaAs QDs on (0 0 1), vicinal (0 0 1), (1 1 0), and (3 1 1)A GaAs surfaces. On (3 1 1)A GaAs, QDs are formed with higher density and smaller height compared to (0 0 1) and (1 1 0), which is attributed to a higher energy barrier for surface diffusion. Values of the surface diffusion barrier are determined and its influence on temperature-dependent QD density is studied by means of a QD growth model. On vicinal (0 0 1) surfaces, step bunches are found to act as preferred nucleation sites for GaAs QDs which opens the possibility for a lateral positioning of the QDs by pre-patterning. © 2008 Elsevier B.V. All rights reserved.
Lizenz:
  • info:eu-repo/semantics/closedAccess
Quellsystem:
Forschungsinformationssystem der UHH
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oai:www.edit.fis.uni-hamburg.de:publications/8e340696-4802-47b2-830d-8585ae456dff