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Surface smoothing and native oxide suppression on Zn doped aerotaxy GaAs nanowires

Yngman, Sofie LU ; McKibbin, Sarah R. LU ; Knutsson, Johan V. LU ; Troian, Andrea LU ; Yang, Fangfang LU ; Magnusson, Martin H. LU ; Samuelson, Lars LU ; Timm, Rainer LU and Mikkelsen, Anders LU (2019) In Journal of Applied Physics 125(2).
Abstract

Aerotaxy, a recently invented aerosol-based growth method for nanostructures, has been shown to hold great promise in making III-V nanowires more accessible for cheap mass-production. Aerotaxy nanowire surface structure and chemistry, however, remains unexplored, which is unfortunate since this can influence (opto)electronic properties. We investigate the surfaces of aerotaxy grown GaAs nanowires using synchrotron based high resolution X-ray photoelectron spectroscopy and high resolution atomic force microscopy. We observe that increasing the concentration of the p-type dopant diethylzinc to very high levels during nanowire growth significantly changes the surface morphology and leads to a strong suppression of native surface oxide... (More)

Aerotaxy, a recently invented aerosol-based growth method for nanostructures, has been shown to hold great promise in making III-V nanowires more accessible for cheap mass-production. Aerotaxy nanowire surface structure and chemistry, however, remains unexplored, which is unfortunate since this can influence (opto)electronic properties. We investigate the surfaces of aerotaxy grown GaAs nanowires using synchrotron based high resolution X-ray photoelectron spectroscopy and high resolution atomic force microscopy. We observe that increasing the concentration of the p-type dopant diethylzinc to very high levels during nanowire growth significantly changes the surface morphology and leads to a strong suppression of native surface oxide formation. Our findings indicate that up to 1.8 monolayers of Zn are present on the nanowire surface after growth. Finally, we find that this also influences the Fermi level pinning of the surface. We suggest that Zn present on the surface after growth could play a role in the strongly hindered oxidation of the III-V compound when exposed to air. The aerotaxy nanowires generally exhibit a round cross section, while a significant smoothening of the surface morphology along the nanowire appears for very high nominal doping levels likely as a result of slight reshaping during growth in the presence of Zn. Given that surface oxide and a rough morphology can be detrimental to nanowire electrical and optical performance, the ability to reduce them as a side effect of dopant introduction will benefit future applications. Finally, the observed hindering of oxidation during air transport can allow for reliable post-growth processing in separate systems.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Applied Physics
volume
125
issue
2
publisher
American Institute of Physics
external identifiers
  • scopus:85059800445
ISSN
0021-8979
DOI
10.1063/1.5058727
language
English
LU publication?
yes
id
33c4f6e0-eea1-4518-bea0-92a532edcede
date added to LUP
2019-01-23 12:08:07
date last changed
2019-02-20 11:44:04
@article{33c4f6e0-eea1-4518-bea0-92a532edcede,
  abstract     = {<p>Aerotaxy, a recently invented aerosol-based growth method for nanostructures, has been shown to hold great promise in making III-V nanowires more accessible for cheap mass-production. Aerotaxy nanowire surface structure and chemistry, however, remains unexplored, which is unfortunate since this can influence (opto)electronic properties. We investigate the surfaces of aerotaxy grown GaAs nanowires using synchrotron based high resolution X-ray photoelectron spectroscopy and high resolution atomic force microscopy. We observe that increasing the concentration of the p-type dopant diethylzinc to very high levels during nanowire growth significantly changes the surface morphology and leads to a strong suppression of native surface oxide formation. Our findings indicate that up to 1.8 monolayers of Zn are present on the nanowire surface after growth. Finally, we find that this also influences the Fermi level pinning of the surface. We suggest that Zn present on the surface after growth could play a role in the strongly hindered oxidation of the III-V compound when exposed to air. The aerotaxy nanowires generally exhibit a round cross section, while a significant smoothening of the surface morphology along the nanowire appears for very high nominal doping levels likely as a result of slight reshaping during growth in the presence of Zn. Given that surface oxide and a rough morphology can be detrimental to nanowire electrical and optical performance, the ability to reduce them as a side effect of dopant introduction will benefit future applications. Finally, the observed hindering of oxidation during air transport can allow for reliable post-growth processing in separate systems.</p>},
  articleno    = {025303},
  author       = {Yngman, Sofie and McKibbin, Sarah R. and Knutsson, Johan V. and Troian, Andrea and Yang, Fangfang and Magnusson, Martin H. and Samuelson, Lars and Timm, Rainer and Mikkelsen, Anders},
  issn         = {0021-8979},
  language     = {eng},
  number       = {2},
  publisher    = {American Institute of Physics},
  series       = {Journal of Applied Physics},
  title        = {Surface smoothing and native oxide suppression on Zn doped aerotaxy GaAs nanowires},
  url          = {http://dx.doi.org/10.1063/1.5058727},
  volume       = {125},
  year         = {2019},
}