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Title: Structural and optical properties of InGaN--GaN nanowire heterostructures grown by molecular beam epitaxy

InGaN/GaN nanowire (NW) heterostructures grown by plasma assisted molecular beam epitaxy were studied in comparison to their GaN and InGaN counterparts. The InGaN/GaN heterostructure NWs are composed of a GaN NW, a thin InGaN shell, and a multifaceted InGaN cap wrapping the top part of the GaN NW. High-resolution transmission electron microscopy (HRTEM) images taken from different parts of a InGaN/GaN NW show a wurtzite structure of the GaN core and the epitaxial InGaN shell around it, while additional crystallographic domains are observed whithin the InGaN cap region. Large changes in the lattice parameter along the wire, from pure GaN to higher In concentration demonstrate the successful growth of a complex InGaN/GaN NW heterostructure. Photoluminescence (PL) spectra of these heterostructure NW ensembles show rather broad and intense emission peak at 2.1 eV. However, μ-PL spectra measured on single NWs reveal a reduced broadening of the visible luminescence. The analysis of the longitudinal optical phonon Raman peak position and its shape reveal a variation in the In content between 20% and 30%, in agreement with the values estimated by PL and HRTEM investigations. The reported studies are important for understanding of the growth and properties of NW heterostructures suitable for applicationsmore » in optoelectronics and photovoltaics.« less
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [3] ;  [3] ;  [4] ;  [4] ;  [5] ;  [5] ;  [5] ;  [6]
  1. Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany)
  2. Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States)
  4. Inst. Juame Almera, Barcelona (Spain)
  5. Univ. of Wurzburg (Germany)
  6. Institute of Bio- and Nanosystems (IBN-1), Research Centre Juelich GmbH and JARA-FIT Fundamentals of Future Information Technology (Germany)
Publication Date:
OSTI Identifier:
1076502
Grant/Contract Number:
AC02-98CH1-886; MAT2007-63617
Type:
Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 109; Journal Issue: 1; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)
Research Org:
Institute of Bio- and Nanosystems (IBN-1), Research Centre Jülich GmbH and JARA-FIT Fundamentals of FutureInformation Technology (Germany); Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE EE Office of Technology Development (EE-20)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY NANOWIRE; INGAN ON GAN; CATALYST-FREE; MBE; GANIN