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Nanoscale mapping of carrier collection in single nanowire solar cells using X-ray beam induced current

Chayanun, Lert LU ; Otnes, Gaute LU ; Troian, Andrea LU ; Hammarberg, Susanna LU ; Salomon, Damien; Borgström, Magnus T. LU and Wallentin, Jesper LU (2019) In Journal of Synchrotron Radiation
Abstract

Here it is demonstrated how nanofocused X-ray beam induced current (XBIC) can be used to quantitatively map the spatially dependent carrier collection probability within nanostructured solar cells. The photocurrent generated by a 50 nm-diameter X-ray beam was measured as a function of position, bias and flux in single p–i–n doped solar-cell nanowires. The signal gathered mostly from the middle segment decays exponentially toward the p- and n-segments, with a characteristic decay length that varies between 50 nm and 750 nm depending on the flux and the applied bias. The amplitude of the XBIC shows saturation at reverse bias, which indicates that most carriers are collected. At forward bias, the relevant condition for solar cells, the... (More)

Here it is demonstrated how nanofocused X-ray beam induced current (XBIC) can be used to quantitatively map the spatially dependent carrier collection probability within nanostructured solar cells. The photocurrent generated by a 50 nm-diameter X-ray beam was measured as a function of position, bias and flux in single p–i–n doped solar-cell nanowires. The signal gathered mostly from the middle segment decays exponentially toward the p- and n-segments, with a characteristic decay length that varies between 50 nm and 750 nm depending on the flux and the applied bias. The amplitude of the XBIC shows saturation at reverse bias, which indicates that most carriers are collected. At forward bias, the relevant condition for solar cells, the carrier collection is only efficient in a small region. Comparison with finite element modeling suggests that this is due to unintentional p-doping in the middle segment. It is expected that nanofocused XBIC could be used to investigate carrier collection in a wide range of nanostructured solar cells.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
internal quantum efficiency, IQE, nanowires, solar cells, X-ray beam induced current, XBIC
in
Journal of Synchrotron Radiation
publisher
Wiley-Blackwell
external identifiers
  • scopus:85058416435
ISSN
0909-0495
DOI
10.1107/S1600577518015229
language
English
LU publication?
yes
id
1dd844ef-248d-4d1d-b66b-ed2be9e67376
date added to LUP
2019-01-09 12:38:12
date last changed
2019-02-20 11:42:14
@article{1dd844ef-248d-4d1d-b66b-ed2be9e67376,
  abstract     = {<p>Here it is demonstrated how nanofocused X-ray beam induced current (XBIC) can be used to quantitatively map the spatially dependent carrier collection probability within nanostructured solar cells. The photocurrent generated by a 50 nm-diameter X-ray beam was measured as a function of position, bias and flux in single p–i–n doped solar-cell nanowires. The signal gathered mostly from the middle segment decays exponentially toward the p- and n-segments, with a characteristic decay length that varies between 50 nm and 750 nm depending on the flux and the applied bias. The amplitude of the XBIC shows saturation at reverse bias, which indicates that most carriers are collected. At forward bias, the relevant condition for solar cells, the carrier collection is only efficient in a small region. Comparison with finite element modeling suggests that this is due to unintentional p-doping in the middle segment. It is expected that nanofocused XBIC could be used to investigate carrier collection in a wide range of nanostructured solar cells.</p>},
  author       = {Chayanun, Lert and Otnes, Gaute and Troian, Andrea and Hammarberg, Susanna and Salomon, Damien and Borgström, Magnus T. and Wallentin, Jesper},
  issn         = {0909-0495},
  keyword      = {internal quantum efficiency,IQE,nanowires,solar cells,X-ray beam induced current,XBIC},
  language     = {eng},
  publisher    = {Wiley-Blackwell},
  series       = {Journal of Synchrotron Radiation},
  title        = {Nanoscale mapping of carrier collection in single nanowire solar cells using X-ray beam induced current},
  url          = {http://dx.doi.org/10.1107/S1600577518015229},
  year         = {2019},
}