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Raman scattering reveals strong LO-phonon-hole-plasmon coupling in nominally undoped GaAsBi: optical determination of carrier concentration

Journal Article


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Abstract


  • We report room-temperature Raman scattering studies of nominally undoped (100) GaAs1−xBix epitaxial layers exhibiting Bi-induced (p-type) longitudinal-optical-plasmon-coupled (LOPC) modes for 0.018 ≤ x ≤ 0.048. Redshifts in the GaAs-like optical modes due to alloying are evaluated and are paralleled by strong damping of the LOPC. The relative integrated Raman intensities of LO(Γ) and LOPC ALO/ALOPC are characteristic of heavily doped p-GaAs, with a remarkable near total screening of the LO(Γ) phonon (ALO/ALOPC → 0) for larger Bi concentrations. A method of spectral analysis is set out which yields estimates of hole concentrations in excess of 5 × 1017cm−3 and correlates with the Bi molar fraction. These findings are in general agreement with recent electrical transport measurements performed on the alloy, and while the absolute size of the hole concentrations differ, likely origins for the discrepancy are discussed. We conclude that the damped LO-phonon-hole-plasmon coupling phenomena plays a dominant role in Raman scattering from unpassivated nominally undoped GaAsBi.

Authors


  •   Steele, Julian (external author)
  •   Lewis, R A.
  •   Henini, M (external author)
  •   Lemine, O M. (external author)
  •   Fan, D. (external author)
  •   Mazur, Yu. I. (external author)
  •   Dorogan, V G. (external author)
  •   Grant, P C. (external author)
  •   Yu, S.-Q (external author)
  •   Salamo, G J. (external author)

Publication Date


  • 2014

Citation


  • Steele, J. A., Lewis, R. A., Henini, M., Lemine, O. M., Fan, D., Mazur, Y. I., Dorogan, V. G., Grant, P. C., Yu, S. & Salamo, G. J. (2014). Raman scattering reveals strong LO-phonon-hole-plasmon coupling in nominally undoped GaAsBi: optical determination of carrier concentration. Optics Express, 22 (10), 11680-11689.

Scopus Eid


  • 2-s2.0-84901249556

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=3264&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/2255

Number Of Pages


  • 9

Start Page


  • 11680

End Page


  • 11689

Volume


  • 22

Issue


  • 10

Place Of Publication


  • http://dx.doi.org/10.1364/OE.22.011680

Abstract


  • We report room-temperature Raman scattering studies of nominally undoped (100) GaAs1−xBix epitaxial layers exhibiting Bi-induced (p-type) longitudinal-optical-plasmon-coupled (LOPC) modes for 0.018 ≤ x ≤ 0.048. Redshifts in the GaAs-like optical modes due to alloying are evaluated and are paralleled by strong damping of the LOPC. The relative integrated Raman intensities of LO(Γ) and LOPC ALO/ALOPC are characteristic of heavily doped p-GaAs, with a remarkable near total screening of the LO(Γ) phonon (ALO/ALOPC → 0) for larger Bi concentrations. A method of spectral analysis is set out which yields estimates of hole concentrations in excess of 5 × 1017cm−3 and correlates with the Bi molar fraction. These findings are in general agreement with recent electrical transport measurements performed on the alloy, and while the absolute size of the hole concentrations differ, likely origins for the discrepancy are discussed. We conclude that the damped LO-phonon-hole-plasmon coupling phenomena plays a dominant role in Raman scattering from unpassivated nominally undoped GaAsBi.

Authors


  •   Steele, Julian (external author)
  •   Lewis, R A.
  •   Henini, M (external author)
  •   Lemine, O M. (external author)
  •   Fan, D. (external author)
  •   Mazur, Yu. I. (external author)
  •   Dorogan, V G. (external author)
  •   Grant, P C. (external author)
  •   Yu, S.-Q (external author)
  •   Salamo, G J. (external author)

Publication Date


  • 2014

Citation


  • Steele, J. A., Lewis, R. A., Henini, M., Lemine, O. M., Fan, D., Mazur, Y. I., Dorogan, V. G., Grant, P. C., Yu, S. & Salamo, G. J. (2014). Raman scattering reveals strong LO-phonon-hole-plasmon coupling in nominally undoped GaAsBi: optical determination of carrier concentration. Optics Express, 22 (10), 11680-11689.

Scopus Eid


  • 2-s2.0-84901249556

Ro Full-text Url


  • http://ro.uow.edu.au/cgi/viewcontent.cgi?article=3264&context=eispapers

Ro Metadata Url


  • http://ro.uow.edu.au/eispapers/2255

Number Of Pages


  • 9

Start Page


  • 11680

End Page


  • 11689

Volume


  • 22

Issue


  • 10

Place Of Publication


  • http://dx.doi.org/10.1364/OE.22.011680