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Title: Electronic structure, morphology and emission polarization of enhanced symmetry InAs quantum-dot-like structures grown on InP substrates by molecular beam epitaxy

The optical and structural properties of a new kind of InAs/InGaAlAs/InP quantum dot (QD)-like objects grown by molecular beam epitaxy have been investigated. These nanostructures were found to have significantly more symmetrical shapes compared to the commonly obtained dash-like geometries typical of this material system. The enhanced symmetry has been achieved due to the use of an As{sub 2} source and the consequent shorter migration length of the indium atoms. Structural studies based on a combination of scanning transmission electron microscopy (STEM) and atom probe tomography (APT) provided detailed information on both the structure and composition distribution within an individual nanostructure. However, it was not possible to determine the lateral aspect ratio from STEM or APT. To verify the in-plane geometry, electronic structure calculations, including the energy levels and transition oscillator strength for the QDs have been performed using an eight-band k·p model and realistic system parameters. The results of calculations were compared to measured polarization-resolved photoluminescence data. On the basis of measured degree of linear polarization of the surface emission, the in-plane shape of the QDs has been assessed proving a substantial increase in lateral symmetry. This results in quantum-dot rather than quantum-dash like properties, consistent with expectations basedmore » on the growth conditions and the structural data.« less
Authors:
; ; ; ;  [1] ; ;  [2] ; ; ; ;  [3] ; ;  [4] ;  [5]
  1. Institute of Physics, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław (Poland)
  2. Technische Physik, Institute of Nanostructure Technology and Analytics, CINSaT, University of Kassel, Heinrich Plett-Str. 40, D-34132 Kassel (Germany)
  3. Department of Electrical Engineering, Technion, Haifa 32000 (Israel)
  4. Department of Materials Science and Engineering, Technion, Haifa 32000 (Israel)
  5. Fraunhofer Institute for Photonic Microsystems, Center for Nanoelectronic Technologies, Königsbrücker Straße 180, D-01099 Dresden (Germany)
Publication Date:
OSTI Identifier:
22218115
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 9; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COMPARATIVE EVALUATIONS; ELECTRONIC STRUCTURE; GALLIUM ARSENIDES; GEOMETRY; INDIUM ARSENIDES; INDIUM PHOSPHIDES; MIGRATION LENGTH; MOLECULAR BEAM EPITAXY; MORPHOLOGY; PHOTOLUMINESCENCE; POLARIZATION; QUANTUM DOTS; SEMICONDUCTOR MATERIALS; SHAPE; SUBSTRATES; SYMMETRY; TOMOGRAPHY; TRANSMISSION ELECTRON MICROSCOPY