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Infrared photodetectors in heterostructure nanowires

Pettersson, H ; Trägårdh, Johanna LU ; Persson, Ann LU ; Landin, L ; Hessman, Dan LU and Samuelson, Lars LU (2006) In Nano Letters 6(2). p.229-232
Abstract
We report on spectrally resolved photocurrent measurements on single self-assembled nanowire heterostructures. The wires, typically 3 mu m long with an average diameter of 85 nm, consist of InAs with a 1 mu m central part of InAsP. Two different sets of wires were prepared with phosphorus contents of 15 +/- 3% and 35 +/- 3%, respectively, as determined by energy-dispersive spectroscopy measurements made in transmission electron microscopy. Ohmic contacts are fabricated to the InAs ends of the wire using e-beam lithography. The conduction band offset between the InAs and InAsP regions virtually removes the dark current through the wires at low temperature. In the optical experiments, interband excitation in the phosphorus-rich part of the... (More)
We report on spectrally resolved photocurrent measurements on single self-assembled nanowire heterostructures. The wires, typically 3 mu m long with an average diameter of 85 nm, consist of InAs with a 1 mu m central part of InAsP. Two different sets of wires were prepared with phosphorus contents of 15 +/- 3% and 35 +/- 3%, respectively, as determined by energy-dispersive spectroscopy measurements made in transmission electron microscopy. Ohmic contacts are fabricated to the InAs ends of the wire using e-beam lithography. The conduction band offset between the InAs and InAsP regions virtually removes the dark current through the wires at low temperature. In the optical experiments, interband excitation in the phosphorus-rich part of the wires results in a photocurrent with threshold energies of about 0.65 and 0.82 eV, respectively, in qualitative agreement with the expected band gap of the two compositions. Furthermore, a strong polarization dependence is observed with an order of magnitude larger photocurrent for light polarized parallel to the wire than for light polarized perpendicular to the wire. We believe that these wires form promising candidates as nanoscale infrared polarization-sensitive photodetectors. (Less)
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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Nano Letters
volume
6
issue
2
pages
229 - 232
publisher
The American Chemical Society (ACS)
external identifiers
  • wos:000235532700017
  • pmid:16464040
  • scopus:33644914252
ISSN
1530-6992
DOI
10.1021/nl052170l
language
English
LU publication?
yes
id
6d96d586-bb08-42f5-80bb-c839e58c2187 (old id 417056)
date added to LUP
2016-04-01 16:14:37
date last changed
2021-09-29 03:06:48
@article{6d96d586-bb08-42f5-80bb-c839e58c2187,
  abstract     = {We report on spectrally resolved photocurrent measurements on single self-assembled nanowire heterostructures. The wires, typically 3 mu m long with an average diameter of 85 nm, consist of InAs with a 1 mu m central part of InAsP. Two different sets of wires were prepared with phosphorus contents of 15 +/- 3% and 35 +/- 3%, respectively, as determined by energy-dispersive spectroscopy measurements made in transmission electron microscopy. Ohmic contacts are fabricated to the InAs ends of the wire using e-beam lithography. The conduction band offset between the InAs and InAsP regions virtually removes the dark current through the wires at low temperature. In the optical experiments, interband excitation in the phosphorus-rich part of the wires results in a photocurrent with threshold energies of about 0.65 and 0.82 eV, respectively, in qualitative agreement with the expected band gap of the two compositions. Furthermore, a strong polarization dependence is observed with an order of magnitude larger photocurrent for light polarized parallel to the wire than for light polarized perpendicular to the wire. We believe that these wires form promising candidates as nanoscale infrared polarization-sensitive photodetectors.},
  author       = {Pettersson, H and Trägårdh, Johanna and Persson, Ann and Landin, L and Hessman, Dan and Samuelson, Lars},
  issn         = {1530-6992},
  language     = {eng},
  number       = {2},
  pages        = {229--232},
  publisher    = {The American Chemical Society (ACS)},
  series       = {Nano Letters},
  title        = {Infrared photodetectors in heterostructure nanowires},
  url          = {http://dx.doi.org/10.1021/nl052170l},
  doi          = {10.1021/nl052170l},
  volume       = {6},
  year         = {2006},
}