Complex dielectric function of GaA s1-x B ix as a function of Bi content

Mahsa Mahtab, Ron Synowicki, Vahid Bahrami-Yekta, Lars C. Bannow, Stephan W Koch, Ryan B. Lewis, Thomas Tiedje

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The complex dielectric constants of GaAs1-xBix alloys grown by molecular beam epitaxy with x=0% to 17% have been measured over the spectral range from 0.37 to 9.1 eV using spectroscopic ellipsometry. Critical points in the joint density of states have been analyzed by fitting the line shape of the Van Hove singularities in the dielectric function derived from the ellipsometry data. The critical points generally match similar critical points in the dielectric function of GaAs with at least one alternative critical point. The energy of the critical points involving transitions from the top of the valence band show a strong dependence on Bi concentration similar to the composition dependence of the band gap, while the other critical points have a weaker dependence on Bi concentration. The measured composition dependence of the band gap and the energy of the split-off hole band are in good agreement with density functional calculations. The composition dependence of the index of refraction in the vicinity of the band gap for GaAs1-xBix alloys is an order of magnitude larger than the composition dependence of the index of refraction in Ga1-xInxAs alloys.

Original languageEnglish (US)
Article number054601
JournalPhysical Review Materials
Volume3
Issue number5
DOIs
StatePublished - May 3 2019
Externally publishedYes

Fingerprint

critical point
Energy gap
Refraction
Chemical analysis
ellipsometry
Spectroscopic ellipsometry
refraction
Ellipsometry
Electron transitions
Valence bands
Molecular beam epitaxy
Density functional theory
Permittivity
trucks
line shape
molecular beam epitaxy
permittivity
valence
energy

ASJC Scopus subject areas

  • Materials Science(all)
  • Physics and Astronomy (miscellaneous)

Cite this

Mahtab, M., Synowicki, R., Bahrami-Yekta, V., Bannow, L. C., Koch, S. W., Lewis, R. B., & Tiedje, T. (2019). Complex dielectric function of GaA s1-x B ix as a function of Bi content. Physical Review Materials, 3(5), [054601]. https://doi.org/10.1103/PhysRevMaterials.3.054601

Complex dielectric function of GaA s1-x B ix as a function of Bi content. / Mahtab, Mahsa; Synowicki, Ron; Bahrami-Yekta, Vahid; Bannow, Lars C.; Koch, Stephan W; Lewis, Ryan B.; Tiedje, Thomas.

In: Physical Review Materials, Vol. 3, No. 5, 054601, 03.05.2019.

Research output: Contribution to journalArticle

Mahtab, M, Synowicki, R, Bahrami-Yekta, V, Bannow, LC, Koch, SW, Lewis, RB & Tiedje, T 2019, 'Complex dielectric function of GaA s1-x B ix as a function of Bi content', Physical Review Materials, vol. 3, no. 5, 054601. https://doi.org/10.1103/PhysRevMaterials.3.054601
Mahtab, Mahsa ; Synowicki, Ron ; Bahrami-Yekta, Vahid ; Bannow, Lars C. ; Koch, Stephan W ; Lewis, Ryan B. ; Tiedje, Thomas. / Complex dielectric function of GaA s1-x B ix as a function of Bi content. In: Physical Review Materials. 2019 ; Vol. 3, No. 5.
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