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Growth selectivity control of InAs shells on crystal phase engineered GaAs nanowires

Gómez, Víctor J. LU orcid ; Marnauza, Mikelis LU orcid ; Dick, Kimberly A. LU and Lehmann, Sebastian LU (2022) In Nanoscale Advances 4(16). p.3330-3341
Abstract

In this work we demonstrate a two-fold selectivity control of InAs shells grown on crystal phase and morphology engineered GaAs nanowire (NW) core templates. This selectivity occurs driven by differences in surface energies of the NW core facets. The occurrence of the different facets itself is controlled by either forming different crystal phases or additional tuning of the core NW morphology. First, in order to study the crystal phase selectivity, GaAs NW cores with an engineered crystal phase in the axial direction were employed. A crystal phase selective growth of InAs on GaAs was found for high growth rates and short growth times. Secondly, the facet-dependant selectivity of InAs growth was studied on crystal phase controlled GaAs... (More)

In this work we demonstrate a two-fold selectivity control of InAs shells grown on crystal phase and morphology engineered GaAs nanowire (NW) core templates. This selectivity occurs driven by differences in surface energies of the NW core facets. The occurrence of the different facets itself is controlled by either forming different crystal phases or additional tuning of the core NW morphology. First, in order to study the crystal phase selectivity, GaAs NW cores with an engineered crystal phase in the axial direction were employed. A crystal phase selective growth of InAs on GaAs was found for high growth rates and short growth times. Secondly, the facet-dependant selectivity of InAs growth was studied on crystal phase controlled GaAs cores which were additionally morphology-tuned by homoepitaxial overgrowth. Following this route, the original hexagonal cores with {110} sidewalls were converted into triangular truncated NWs with ridges and predominantly {112}B facets. By precisely tuning the growth parameters, the growth of InAs is promoted over the ridges and reduced over the {112}B facets with indications of also preserving the crystal phase selectivity. In all cases (different crystal phase and facet termination), selectivity is lost for extended growth times, thus, limiting the total thickness of the shell grown under selective conditions. To overcome this issue we propose a 2-step growth approach, combining a high growth rate step followed by a low growth rate step. The control over the thickness of the InAs shells while maintaining the selectivity is demonstrated by means of a detailed transmission electron microscopy analysis. This proposed 2-step growth approach enables new functionalities in 1-D structures formed by using bottom-up techniques, with a high degree of control over shell thickness and deposition selectivity.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Nanoscale Advances
volume
4
issue
16
pages
12 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:85129208948
  • pmid:36131713
ISSN
2516-0230
DOI
10.1039/d2na00109h
language
English
LU publication?
yes
id
7e98a5a8-738c-47af-8ca2-f4772d748865
date added to LUP
2022-08-15 08:58:50
date last changed
2024-06-13 18:12:23
@article{7e98a5a8-738c-47af-8ca2-f4772d748865,
  abstract     = {{<p>In this work we demonstrate a two-fold selectivity control of InAs shells grown on crystal phase and morphology engineered GaAs nanowire (NW) core templates. This selectivity occurs driven by differences in surface energies of the NW core facets. The occurrence of the different facets itself is controlled by either forming different crystal phases or additional tuning of the core NW morphology. First, in order to study the crystal phase selectivity, GaAs NW cores with an engineered crystal phase in the axial direction were employed. A crystal phase selective growth of InAs on GaAs was found for high growth rates and short growth times. Secondly, the facet-dependant selectivity of InAs growth was studied on crystal phase controlled GaAs cores which were additionally morphology-tuned by homoepitaxial overgrowth. Following this route, the original hexagonal cores with {110} sidewalls were converted into triangular truncated NWs with ridges and predominantly {112}<sub>B</sub> facets. By precisely tuning the growth parameters, the growth of InAs is promoted over the ridges and reduced over the {112}<sub>B</sub> facets with indications of also preserving the crystal phase selectivity. In all cases (different crystal phase and facet termination), selectivity is lost for extended growth times, thus, limiting the total thickness of the shell grown under selective conditions. To overcome this issue we propose a 2-step growth approach, combining a high growth rate step followed by a low growth rate step. The control over the thickness of the InAs shells while maintaining the selectivity is demonstrated by means of a detailed transmission electron microscopy analysis. This proposed 2-step growth approach enables new functionalities in 1-D structures formed by using bottom-up techniques, with a high degree of control over shell thickness and deposition selectivity.</p>}},
  author       = {{Gómez, Víctor J. and Marnauza, Mikelis and Dick, Kimberly A. and Lehmann, Sebastian}},
  issn         = {{2516-0230}},
  language     = {{eng}},
  number       = {{16}},
  pages        = {{3330--3341}},
  publisher    = {{Royal Society of Chemistry}},
  series       = {{Nanoscale Advances}},
  title        = {{Growth selectivity control of InAs shells on crystal phase engineered GaAs nanowires}},
  url          = {{http://dx.doi.org/10.1039/d2na00109h}},
  doi          = {{10.1039/d2na00109h}},
  volume       = {{4}},
  year         = {{2022}},
}