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Extracting band structure characteristics of GaSb/InAs core-shell nanowires from thermoelectric properties

Viñas, Florinda LU ; Xu, H. Q. LU and Leijnse, Martin LU (2017) In Physical Review B 95(11).
Abstract

Nanowires with a GaSb core and an InAs shell (and the inverted structure) are interesting for studies of electron-hole hybridization and interaction effects due to the bulk broken band-gap alignment at the material interface. We have used eight-band k·p theory together with the envelope function approximation to calculate the band structure of such nanowires. For a fixed core radius, as a function of shell thickness the band structure changes from metallic (for a thick shell) to semiconducting (for a thin shell) with a gap induced by quantum confinement. For intermediate shell thickness, a different gapped band structure can appear, where the gap is induced by hybridization between the valence band in GaSb and the conduction band in... (More)

Nanowires with a GaSb core and an InAs shell (and the inverted structure) are interesting for studies of electron-hole hybridization and interaction effects due to the bulk broken band-gap alignment at the material interface. We have used eight-band k·p theory together with the envelope function approximation to calculate the band structure of such nanowires. For a fixed core radius, as a function of shell thickness the band structure changes from metallic (for a thick shell) to semiconducting (for a thin shell) with a gap induced by quantum confinement. For intermediate shell thickness, a different gapped band structure can appear, where the gap is induced by hybridization between the valence band in GaSb and the conduction band in InAs. To establish a relationship between the nanowire band structures and signatures in thermoelectrical measurements, we use the calculated energy dispersions as input to the Boltzmann equation and to ballistic transport equations to study the diffusive limit and the ballistic limit, respectively. Our theoretical results provide a guide for experiments, showing how thermoelectric measurements in a gated setup can be used to distinguish between different types of band gaps, or tune the system into a regime with few electrons and few holes, which can be of interest for studies of exciton physics.

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Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B
volume
95
issue
11
publisher
American Physical Society
external identifiers
  • scopus:85015974262
  • wos:000396430300003
ISSN
1098-0121
DOI
10.1103/PhysRevB.95.115420
language
English
LU publication?
yes
id
d8eb71ca-bcf7-4063-8766-4dd196b27b05
date added to LUP
2017-04-05 13:30:16
date last changed
2018-04-15 04:42:31
@article{d8eb71ca-bcf7-4063-8766-4dd196b27b05,
  abstract     = {<p>Nanowires with a GaSb core and an InAs shell (and the inverted structure) are interesting for studies of electron-hole hybridization and interaction effects due to the bulk broken band-gap alignment at the material interface. We have used eight-band k·p theory together with the envelope function approximation to calculate the band structure of such nanowires. For a fixed core radius, as a function of shell thickness the band structure changes from metallic (for a thick shell) to semiconducting (for a thin shell) with a gap induced by quantum confinement. For intermediate shell thickness, a different gapped band structure can appear, where the gap is induced by hybridization between the valence band in GaSb and the conduction band in InAs. To establish a relationship between the nanowire band structures and signatures in thermoelectrical measurements, we use the calculated energy dispersions as input to the Boltzmann equation and to ballistic transport equations to study the diffusive limit and the ballistic limit, respectively. Our theoretical results provide a guide for experiments, showing how thermoelectric measurements in a gated setup can be used to distinguish between different types of band gaps, or tune the system into a regime with few electrons and few holes, which can be of interest for studies of exciton physics.</p>},
  articleno    = {115420},
  author       = {Viñas, Florinda and Xu, H. Q. and Leijnse, Martin},
  issn         = {1098-0121},
  language     = {eng},
  month        = {03},
  number       = {11},
  publisher    = {American Physical Society},
  series       = {Physical Review B},
  title        = {Extracting band structure characteristics of GaSb/InAs core-shell nanowires from thermoelectric properties},
  url          = {http://dx.doi.org/10.1103/PhysRevB.95.115420},
  volume       = {95},
  year         = {2017},
}