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Temperature dependent electronic band structure of wurtzite GaAs nanowires

Vainorius, Neimantas LU ; Kubitza, Simon; Lehmann, Sebastian LU ; Samuelson, Lars LU ; Dick, Kimberly A. LU and Pistol, Mats Erik LU (2018) In Nanoscale 10(3). p.1481-1486
Abstract

It has recently become possible to grow GaAs in the wurtzite crystal phase. This ability allows interesting tests of band-structure theory. Wurtzite GaAs has two closely spaced direct conduction bands as well as three nondegenerate valence bands. The energies of the band edges are not well known, in particular not as a function of temperature. In order to improve the accuracy we have studied the temperature dependence of the conduction band minimum as well as of the second valence band maximum using resonant Raman scattering (of up to 3LO Raman lines). We find that the temperature dependence of the bandgap in wurtzite GaAs is very similar to that in zinc blende GaAs. Our results show that they have the same band gaps not only at 7 K but... (More)

It has recently become possible to grow GaAs in the wurtzite crystal phase. This ability allows interesting tests of band-structure theory. Wurtzite GaAs has two closely spaced direct conduction bands as well as three nondegenerate valence bands. The energies of the band edges are not well known, in particular not as a function of temperature. In order to improve the accuracy we have studied the temperature dependence of the conduction band minimum as well as of the second valence band maximum using resonant Raman scattering (of up to 3LO Raman lines). We find that the temperature dependence of the bandgap in wurtzite GaAs is very similar to that in zinc blende GaAs. Our results show that they have the same band gaps not only at 7 K but also at room temperature to within 5 meV. This is in some discrepancy with previous work. We find that the energy difference between the first two Γ9V and Γ7V valence bands is constant, around 100 meV, over the investigated temperature range, 7 K to 300 K. Due to a fortuitous spacing of the energy bands we find a very unexpected and strong quadruple resonance in the resonant Raman scattering.

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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Nanoscale
volume
10
issue
3
pages
6 pages
publisher
Royal Society of Chemistry
external identifiers
  • scopus:85040909991
ISSN
2040-3364
DOI
10.1039/c7nr07635e
language
English
LU publication?
yes
id
0c65f7e8-a0ad-446f-88c5-f99838ca3303
date added to LUP
2018-02-05 14:36:42
date last changed
2018-02-06 03:00:03
@article{0c65f7e8-a0ad-446f-88c5-f99838ca3303,
  abstract     = {<p>It has recently become possible to grow GaAs in the wurtzite crystal phase. This ability allows interesting tests of band-structure theory. Wurtzite GaAs has two closely spaced direct conduction bands as well as three nondegenerate valence bands. The energies of the band edges are not well known, in particular not as a function of temperature. In order to improve the accuracy we have studied the temperature dependence of the conduction band minimum as well as of the second valence band maximum using resonant Raman scattering (of up to 3LO Raman lines). We find that the temperature dependence of the bandgap in wurtzite GaAs is very similar to that in zinc blende GaAs. Our results show that they have the same band gaps not only at 7 K but also at room temperature to within 5 meV. This is in some discrepancy with previous work. We find that the energy difference between the first two Γ<sub>9V</sub> and Γ<sub>7V</sub> valence bands is constant, around 100 meV, over the investigated temperature range, 7 K to 300 K. Due to a fortuitous spacing of the energy bands we find a very unexpected and strong quadruple resonance in the resonant Raman scattering.</p>},
  author       = {Vainorius, Neimantas and Kubitza, Simon and Lehmann, Sebastian and Samuelson, Lars and Dick, Kimberly A. and Pistol, Mats Erik},
  issn         = {2040-3364},
  language     = {eng},
  month        = {01},
  number       = {3},
  pages        = {1481--1486},
  publisher    = {Royal Society of Chemistry},
  series       = {Nanoscale},
  title        = {Temperature dependent electronic band structure of wurtzite GaAs nanowires},
  url          = {http://dx.doi.org/10.1039/c7nr07635e},
  volume       = {10},
  year         = {2018},
}