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Simultaneous high-resolution scanning Bragg contrast and ptychographic imaging of a single solar cell nanowire

Wallentin, Jesper LU ; Wilke, Robin N. ; Osterhoff, Markus and Salditt, Tim (2015) In Journal of Applied Crystallography 48. p.1818-1826
Abstract

Simultaneous scanning Bragg contrast and small-angle ptychographic imaging of a single solar cell nanowire are demonstrated, using a nanofocused hard X-ray beam and two detectors. The 2.5 μm-long nanowire consists of a single-crystal InP core of 190 nm diameter, coated with amorphous SiO2 and polycrystalline indium tin oxide. The nanowire was selected and aligned in real space using the small-angle scattering of the 140 × 210 nm X-ray beam. The orientation of the nanowire, as observed in small-angle scattering, was used to find the correct rotation for the Bragg condition. After alignment in real space and rotation, high-resolution (50 nm step) raster scans were performed to simultaneously measure the distribution of small-angle... (More)

Simultaneous scanning Bragg contrast and small-angle ptychographic imaging of a single solar cell nanowire are demonstrated, using a nanofocused hard X-ray beam and two detectors. The 2.5 μm-long nanowire consists of a single-crystal InP core of 190 nm diameter, coated with amorphous SiO2 and polycrystalline indium tin oxide. The nanowire was selected and aligned in real space using the small-angle scattering of the 140 × 210 nm X-ray beam. The orientation of the nanowire, as observed in small-angle scattering, was used to find the correct rotation for the Bragg condition. After alignment in real space and rotation, high-resolution (50 nm step) raster scans were performed to simultaneously measure the distribution of small-angle scattering and Bragg diffraction in the nanowire. Ptychographic reconstruction of the coherent small-angle scattering was used to achieve sub-beam spatial resolution. The small-angle scattering images, which are sensitive to the shape and the electron density of all parts of the nanowire, showed a homogeneous profile along the nanowire axis except at the thicker head region. In contrast, the scanning Bragg diffraction microscopy, which probes only the single-crystal InP core, revealed bending and crystalline inhomogeneity. Both systematic and non-systematic real-space movement of the nanowire were observed as it was rotated, which would have been difficult to reveal only from the Bragg scattering. These results demonstrate the advantages of simultaneously collecting and analyzing the small-angle scattering in Bragg diffraction experiments.

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author
; ; and
publishing date
type
Contribution to journal
publication status
published
subject
keywords
nanowires, ptychography, solar cells, X-ray diffraction
in
Journal of Applied Crystallography
volume
48
pages
9 pages
publisher
International Union of Crystallography
external identifiers
  • scopus:84948799826
ISSN
0021-8898
DOI
10.1107/S1600576715017975
language
English
LU publication?
no
id
0e40ea60-7247-41c3-abf2-d0ae73b490f6
date added to LUP
2017-12-13 16:25:00
date last changed
2022-01-31 00:38:40
@article{0e40ea60-7247-41c3-abf2-d0ae73b490f6,
  abstract     = {{<p>Simultaneous scanning Bragg contrast and small-angle ptychographic imaging of a single solar cell nanowire are demonstrated, using a nanofocused hard X-ray beam and two detectors. The 2.5 μm-long nanowire consists of a single-crystal InP core of 190 nm diameter, coated with amorphous SiO2 and polycrystalline indium tin oxide. The nanowire was selected and aligned in real space using the small-angle scattering of the 140 × 210 nm X-ray beam. The orientation of the nanowire, as observed in small-angle scattering, was used to find the correct rotation for the Bragg condition. After alignment in real space and rotation, high-resolution (50 nm step) raster scans were performed to simultaneously measure the distribution of small-angle scattering and Bragg diffraction in the nanowire. Ptychographic reconstruction of the coherent small-angle scattering was used to achieve sub-beam spatial resolution. The small-angle scattering images, which are sensitive to the shape and the electron density of all parts of the nanowire, showed a homogeneous profile along the nanowire axis except at the thicker head region. In contrast, the scanning Bragg diffraction microscopy, which probes only the single-crystal InP core, revealed bending and crystalline inhomogeneity. Both systematic and non-systematic real-space movement of the nanowire were observed as it was rotated, which would have been difficult to reveal only from the Bragg scattering. These results demonstrate the advantages of simultaneously collecting and analyzing the small-angle scattering in Bragg diffraction experiments.</p>}},
  author       = {{Wallentin, Jesper and Wilke, Robin N. and Osterhoff, Markus and Salditt, Tim}},
  issn         = {{0021-8898}},
  keywords     = {{nanowires; ptychography; solar cells; X-ray diffraction}},
  language     = {{eng}},
  pages        = {{1818--1826}},
  publisher    = {{International Union of Crystallography}},
  series       = {{Journal of Applied Crystallography}},
  title        = {{Simultaneous high-resolution scanning Bragg contrast and ptychographic imaging of a single solar cell nanowire}},
  url          = {{http://dx.doi.org/10.1107/S1600576715017975}},
  doi          = {{10.1107/S1600576715017975}},
  volume       = {{48}},
  year         = {{2015}},
}