Spectroscopic Determination of the Bandgap Crossover Composition in MBE-Grown AlxGa1-xAs

Brian Fluegel; Kirstin Alberi; John Reno; Angelo Mascarenhas

doi:10.7567/JJAP.54.042402

Spectroscopic Determination of the Bandgap Crossover Composition in MBE-Grown AlxGa1-xAs

Brian Fluegel, Kirstin Alberi, John Reno, Angelo Mascarenhas

Sandia National Laboratories

Research output: Contribution to journal › Article › peer-review

3 Scopus Citations

Abstract

The aluminum concentration dependence of the energies of the direct and indirect bandgaps arising from the Γ and Χ conduction bands are measured at 1.7K in the semiconductor alloy Al_xGa_1-xAs. The composition at which the bands cross is determined from photoluminescence of samples grown by molecular-beam epitaxy very close to crossover at x ≈ 0.4. The use of resonant laser excitation and the improved sample linewidth allows excitation intensities as low as 10^-2 W/cm², giving a precise determination of the bound exciton transition energies and their Γ and Χ crossover. Photoluminescence excitation spectroscopy is then used to measure the binding energies of the donor-bound excitons and the Γ free exciton binding energy. After correcting for the Γ- and Χ-dependence of these quantities, the crossover of the bandgap is determined to be at x = 0.401 and E = 2.086 eV.

Original language	American English
Article number	042402
Number of pages	4
Journal	Japanese Journal of Applied Physics, Part 2: Letters
Volume	54
Issue number	4
DOIs	https://doi.org/10.7567/JJAP.54.042402 https://doi.org/10.7567/JJAP.54.042402
State	Published - 2015

Bibliographical note

Publisher Copyright:
© 2015 The Japan Society of Applied Physics.

NREL Publication Number

NREL/JA-5K00-63469

Keywords

AlGaAs
photoluminescence

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title = "Spectroscopic Determination of the Bandgap Crossover Composition in MBE-Grown AlxGa1-xAs",

abstract = "The aluminum concentration dependence of the energies of the direct and indirect bandgaps arising from the Γ and Χ conduction bands are measured at 1.7K in the semiconductor alloy AlxGa1-xAs. The composition at which the bands cross is determined from photoluminescence of samples grown by molecular-beam epitaxy very close to crossover at x ≈ 0.4. The use of resonant laser excitation and the improved sample linewidth allows excitation intensities as low as 10-2 W/cm2, giving a precise determination of the bound exciton transition energies and their Γ and Χ crossover. Photoluminescence excitation spectroscopy is then used to measure the binding energies of the donor-bound excitons and the Γ free exciton binding energy. After correcting for the Γ- and Χ-dependence of these quantities, the crossover of the bandgap is determined to be at x = 0.401 and E = 2.086 eV.",

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author = "Brian Fluegel and Kirstin Alberi and John Reno and Angelo Mascarenhas",

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AU - Fluegel, Brian

AU - Alberi, Kirstin

AU - Reno, John

AU - Mascarenhas, Angelo

PY - 2015

Y1 - 2015

N2 - The aluminum concentration dependence of the energies of the direct and indirect bandgaps arising from the Γ and Χ conduction bands are measured at 1.7K in the semiconductor alloy AlxGa1-xAs. The composition at which the bands cross is determined from photoluminescence of samples grown by molecular-beam epitaxy very close to crossover at x ≈ 0.4. The use of resonant laser excitation and the improved sample linewidth allows excitation intensities as low as 10-2 W/cm2, giving a precise determination of the bound exciton transition energies and their Γ and Χ crossover. Photoluminescence excitation spectroscopy is then used to measure the binding energies of the donor-bound excitons and the Γ free exciton binding energy. After correcting for the Γ- and Χ-dependence of these quantities, the crossover of the bandgap is determined to be at x = 0.401 and E = 2.086 eV.

AB - The aluminum concentration dependence of the energies of the direct and indirect bandgaps arising from the Γ and Χ conduction bands are measured at 1.7K in the semiconductor alloy AlxGa1-xAs. The composition at which the bands cross is determined from photoluminescence of samples grown by molecular-beam epitaxy very close to crossover at x ≈ 0.4. The use of resonant laser excitation and the improved sample linewidth allows excitation intensities as low as 10-2 W/cm2, giving a precise determination of the bound exciton transition energies and their Γ and Χ crossover. Photoluminescence excitation spectroscopy is then used to measure the binding energies of the donor-bound excitons and the Γ free exciton binding energy. After correcting for the Γ- and Χ-dependence of these quantities, the crossover of the bandgap is determined to be at x = 0.401 and E = 2.086 eV.

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KW - photoluminescence

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JO - Japanese Journal of Applied Physics, Part 2: Letters

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Spectroscopic Determination of the Bandgap Crossover Composition in MBE-Grown AlxGa1-xAs

Abstract

Bibliographical note

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Keywords

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