Advanced

Bistability of Contact Angle and Its Role in Achieving Quantum-Thin Self-Assisted GaAs nanowires

Kim, Wonjong ; Dubrovskii, Vladimir G ; Vukajlovic-Plestina, Jelena ; Tütüncüoglu, Gözde ; Francaviglia, Luca ; Güniat, Lucas ; Potts, Heidi LU ; Friedl, Martin ; Leran, Jean-Baptiste and Fontcuberta I Morral, Anna (2018) In Nano Letters 18(1). p.49-57
Abstract

Achieving quantum confinement by bottom-up growth of nanowires has so far been limited to the ability of obtaining stable metal droplets of radii around 10 nm or less. This is within reach for gold-assisted growth. Because of the necessity to maintain the group III droplets during growth, direct synthesis of quantum sized structures becomes much more challenging for self-assisted III-V nanowires. In this work, we elucidate and solve the challenges that involve the synthesis of gallium-assisted quantum-sized GaAs nanowires. We demonstrate the existence of two stable contact angles for the gallium droplet on top of GaAs nanowires. Contact angle around 130° fosters a continuous increase in the nanowire radius, while 90° allows for the... (More)

Achieving quantum confinement by bottom-up growth of nanowires has so far been limited to the ability of obtaining stable metal droplets of radii around 10 nm or less. This is within reach for gold-assisted growth. Because of the necessity to maintain the group III droplets during growth, direct synthesis of quantum sized structures becomes much more challenging for self-assisted III-V nanowires. In this work, we elucidate and solve the challenges that involve the synthesis of gallium-assisted quantum-sized GaAs nanowires. We demonstrate the existence of two stable contact angles for the gallium droplet on top of GaAs nanowires. Contact angle around 130° fosters a continuous increase in the nanowire radius, while 90° allows for the stable growth of ultrathin tops. The experimental results are fully consistent with our model that explains the observed morphological evolution under the two different scenarios. We provide a generalized theory of self-assisted III-V nanowires that describes simultaneously the droplet shape relaxation and the NW radius evolution. Bistability of the contact angle described here should be the general phenomenon that pertains for any vapor-liquid-solid nanowires and significantly refines our picture of how nanowires grow. Overall, our results suggest a new path for obtaining ultrathin one-dimensional III-V nanostructures for studying lateral confinement of carriers.

(Less)
Please use this url to cite or link to this publication:
author
publishing date
type
Contribution to journal
publication status
published
in
Nano Letters
volume
18
issue
1
pages
9 pages
publisher
The American Chemical Society (ACS)
external identifiers
  • pmid:29257895
  • scopus:85040309472
ISSN
1530-6992
DOI
10.1021/acs.nanolett.7b03126
language
English
LU publication?
no
id
00c65411-f3d5-4a5c-964f-546eba887804
date added to LUP
2019-05-15 09:52:08
date last changed
2020-01-16 03:54:19
@article{00c65411-f3d5-4a5c-964f-546eba887804,
  abstract     = {<p>Achieving quantum confinement by bottom-up growth of nanowires has so far been limited to the ability of obtaining stable metal droplets of radii around 10 nm or less. This is within reach for gold-assisted growth. Because of the necessity to maintain the group III droplets during growth, direct synthesis of quantum sized structures becomes much more challenging for self-assisted III-V nanowires. In this work, we elucidate and solve the challenges that involve the synthesis of gallium-assisted quantum-sized GaAs nanowires. We demonstrate the existence of two stable contact angles for the gallium droplet on top of GaAs nanowires. Contact angle around 130° fosters a continuous increase in the nanowire radius, while 90° allows for the stable growth of ultrathin tops. The experimental results are fully consistent with our model that explains the observed morphological evolution under the two different scenarios. We provide a generalized theory of self-assisted III-V nanowires that describes simultaneously the droplet shape relaxation and the NW radius evolution. Bistability of the contact angle described here should be the general phenomenon that pertains for any vapor-liquid-solid nanowires and significantly refines our picture of how nanowires grow. Overall, our results suggest a new path for obtaining ultrathin one-dimensional III-V nanostructures for studying lateral confinement of carriers.</p>},
  author       = {Kim, Wonjong and Dubrovskii, Vladimir G and Vukajlovic-Plestina, Jelena and Tütüncüoglu, Gözde and Francaviglia, Luca and Güniat, Lucas and Potts, Heidi and Friedl, Martin and Leran, Jean-Baptiste and Fontcuberta I Morral, Anna},
  issn         = {1530-6992},
  language     = {eng},
  month        = {01},
  number       = {1},
  pages        = {49--57},
  publisher    = {The American Chemical Society (ACS)},
  series       = {Nano Letters},
  title        = {Bistability of Contact Angle and Its Role in Achieving Quantum-Thin Self-Assisted GaAs nanowires},
  url          = {http://dx.doi.org/10.1021/acs.nanolett.7b03126},
  doi          = {10.1021/acs.nanolett.7b03126},
  volume       = {18},
  year         = {2018},
}