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Microheater Controlled Crystal Phase Engineering of Nanowires Using In Situ Transmission Electron Microscopy

Andersen, Christopher R.Y. LU orcid ; Tornberg, Marcus LU ; Lehmann, Sebastian LU ; Jacobsson, Daniel LU orcid ; Dick, Kimberly A. LU and Mølhave, Kristian S. (2025) In Small Methods 9(1).
Abstract

Crystal Phase Quantum Dots (CPQDs) offer promising properties for quantum communication. How CPQDs can be formed in Au-catalyzed GaAs nanowires using different precursor flows and temperatures by in situ environmental transmission electron microscopy (ETEM) experiments is studied. A III-V gas supply system controls the precursor flow and custom-built micro electro-mechanical system (MEMS) chips with monocrystalline Si-cantilevers are used for temperature control, forming a micrometer-scale metal–organic vapor phase epitaxy (µMOVPE) system. The preferentially formed crystal phases are mapped at different precursor flows and temperatures to determine optimal growth parameters for either crystal phase. To control the position and length of... (More)

Crystal Phase Quantum Dots (CPQDs) offer promising properties for quantum communication. How CPQDs can be formed in Au-catalyzed GaAs nanowires using different precursor flows and temperatures by in situ environmental transmission electron microscopy (ETEM) experiments is studied. A III-V gas supply system controls the precursor flow and custom-built micro electro-mechanical system (MEMS) chips with monocrystalline Si-cantilevers are used for temperature control, forming a micrometer-scale metal–organic vapor phase epitaxy (µMOVPE) system. The preferentially formed crystal phases are mapped at different precursor flows and temperatures to determine optimal growth parameters for either crystal phase. To control the position and length of CPQDs, the time scale for crystal phase change is investigated. The micrometer size of the cantilevers allows temperature shifts of more than 100 °C within 0.1 s at the nanowire growth temperature, which can be much faster than the growth time for a single lattice layer. For controlling the crystal phase, the temperature change is found to be superior to precursor flow, which takes tens of seconds for the crystal phase formation to react. This µMOVPE approach may ultimately provide faster temperature control than bulk MOVPE systems and hence enable engineering sequences of CPQDs with quantum dot lengths and positions defined with atomic precision.

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author
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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
crystal phase engineering, epitaxy, in situ, MEMS, nanowires, TEM, temperature
in
Small Methods
volume
9
issue
1
publisher
John Wiley & Sons Inc.
external identifiers
  • scopus:85204475949
ISSN
2366-9608
DOI
10.1002/smtd.202400728
language
English
LU publication?
yes
id
0afc94a4-9d71-4fd6-bafb-70e5e4a0e012
date added to LUP
2024-11-27 12:56:00
date last changed
2025-04-04 13:51:41
@article{0afc94a4-9d71-4fd6-bafb-70e5e4a0e012,
  abstract     = {{<p>Crystal Phase Quantum Dots (CPQDs) offer promising properties for quantum communication. How CPQDs can be formed in Au-catalyzed GaAs nanowires using different precursor flows and temperatures by in situ environmental transmission electron microscopy (ETEM) experiments is studied. A III-V gas supply system controls the precursor flow and custom-built micro electro-mechanical system (MEMS) chips with monocrystalline Si-cantilevers are used for temperature control, forming a micrometer-scale metal–organic vapor phase epitaxy (µMOVPE) system. The preferentially formed crystal phases are mapped at different precursor flows and temperatures to determine optimal growth parameters for either crystal phase. To control the position and length of CPQDs, the time scale for crystal phase change is investigated. The micrometer size of the cantilevers allows temperature shifts of more than 100 °C within 0.1 s at the nanowire growth temperature, which can be much faster than the growth time for a single lattice layer. For controlling the crystal phase, the temperature change is found to be superior to precursor flow, which takes tens of seconds for the crystal phase formation to react. This µMOVPE approach may ultimately provide faster temperature control than bulk MOVPE systems and hence enable engineering sequences of CPQDs with quantum dot lengths and positions defined with atomic precision.</p>}},
  author       = {{Andersen, Christopher R.Y. and Tornberg, Marcus and Lehmann, Sebastian and Jacobsson, Daniel and Dick, Kimberly A. and Mølhave, Kristian S.}},
  issn         = {{2366-9608}},
  keywords     = {{crystal phase engineering; epitaxy; in situ; MEMS; nanowires; TEM; temperature}},
  language     = {{eng}},
  number       = {{1}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Small Methods}},
  title        = {{Microheater Controlled Crystal Phase Engineering of Nanowires Using In Situ Transmission Electron Microscopy}},
  url          = {{http://dx.doi.org/10.1002/smtd.202400728}},
  doi          = {{10.1002/smtd.202400728}},
  volume       = {{9}},
  year         = {{2025}},
}