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Dislocation-Free and Atomically Flat GaN Hexagonal Microprisms for Device Applications

Khalilian, Maryam LU ; Bi, Zhaoxia LU orcid ; Johansson, Jonas LU orcid ; Lenrick, Filip LU orcid ; Hultin, Olof LU ; Colvin, Jovana LU ; Timm, Rainer LU orcid ; Wallenberg, Reine LU ; Ohlsson, Jonas LU and Pistol, Mats Erik LU , et al. (2020) In Small 16(30).
Abstract

III-nitrides are considered the material of choice for light-emitting diodes (LEDs) and lasers in the visible to ultraviolet spectral range. The development is hampered by lattice and thermal mismatch between the nitride layers and the growth substrate leading to high dislocation densities. In order to overcome the issue, efforts have gone into selected area growth of nanowires (NWs), using their small footprint in the substrate to grow virtually dislocation-free material. Their geometry is defined by six tall side-facets and a pointed tip which limits the design of optoelectronic devices. Growth of dislocation-free and atomically smooth 3D hexagonal GaN micro-prisms with a flat, micrometer-sized top-surface is presented. These... (More)

III-nitrides are considered the material of choice for light-emitting diodes (LEDs) and lasers in the visible to ultraviolet spectral range. The development is hampered by lattice and thermal mismatch between the nitride layers and the growth substrate leading to high dislocation densities. In order to overcome the issue, efforts have gone into selected area growth of nanowires (NWs), using their small footprint in the substrate to grow virtually dislocation-free material. Their geometry is defined by six tall side-facets and a pointed tip which limits the design of optoelectronic devices. Growth of dislocation-free and atomically smooth 3D hexagonal GaN micro-prisms with a flat, micrometer-sized top-surface is presented. These self-forming structures are suitable for optical devices such as low-loss optical cavities for high-efficiency LEDs. The structures are made by annealing GaN NWs with a thick radial shell, reforming them into hexagonal flat-top prisms with six equivalents either m- or s-facets depending on the initial heights of the top pyramid and m-facets of the NWs. This shape is kinetically controlled and the reformation can be explained with a phenomenological model based on Wulff construction that have been developed. It is expected that the results will inspire further research into micron-sized III-nitride-based devices.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
GaN, III-nitride, microprisms, photonics, self-assembly
in
Small
volume
16
issue
30
article number
1907364
publisher
John Wiley & Sons Inc.
external identifiers
  • scopus:85087170705
  • pmid:32578387
ISSN
1613-6810
DOI
10.1002/smll.201907364
language
English
LU publication?
yes
id
93206eb6-07e1-4bbc-b699-7a883fd4e0c8
date added to LUP
2020-07-17 10:03:57
date last changed
2024-05-29 16:51:37
@article{93206eb6-07e1-4bbc-b699-7a883fd4e0c8,
  abstract     = {{<p>III-nitrides are considered the material of choice for light-emitting diodes (LEDs) and lasers in the visible to ultraviolet spectral range. The development is hampered by lattice and thermal mismatch between the nitride layers and the growth substrate leading to high dislocation densities. In order to overcome the issue, efforts have gone into selected area growth of nanowires (NWs), using their small footprint in the substrate to grow virtually dislocation-free material. Their geometry is defined by six tall side-facets and a pointed tip which limits the design of optoelectronic devices. Growth of dislocation-free and atomically smooth 3D hexagonal GaN micro-prisms with a flat, micrometer-sized top-surface is presented. These self-forming structures are suitable for optical devices such as low-loss optical cavities for high-efficiency LEDs. The structures are made by annealing GaN NWs with a thick radial shell, reforming them into hexagonal flat-top prisms with six equivalents either m- or s-facets depending on the initial heights of the top pyramid and m-facets of the NWs. This shape is kinetically controlled and the reformation can be explained with a phenomenological model based on Wulff construction that have been developed. It is expected that the results will inspire further research into micron-sized III-nitride-based devices.</p>}},
  author       = {{Khalilian, Maryam and Bi, Zhaoxia and Johansson, Jonas and Lenrick, Filip and Hultin, Olof and Colvin, Jovana and Timm, Rainer and Wallenberg, Reine and Ohlsson, Jonas and Pistol, Mats Erik and Gustafsson, Anders and Samuelson, Lars}},
  issn         = {{1613-6810}},
  keywords     = {{GaN; III-nitride; microprisms; photonics; self-assembly}},
  language     = {{eng}},
  month        = {{07}},
  number       = {{30}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Small}},
  title        = {{Dislocation-Free and Atomically Flat GaN Hexagonal Microprisms for Device Applications}},
  url          = {{http://dx.doi.org/10.1002/smll.201907364}},
  doi          = {{10.1002/smll.201907364}},
  volume       = {{16}},
  year         = {{2020}},
}