Investigation of the conduction bandstructure in (001) oriented type II GaAs/AlAs short period superlattices using (100) uniaxial stress

W. R. Tribe, P. C. Klipstein, R. Grey, J. S. Roberts, G. W. Smith

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

We present an investigation of the effects of uniaxial stress on the conduction band alignment of type II GaAs/AlAs short period superlattices using photoluminescence (PL) spectroscopy. In the absence of pressure, the conduction band ground state derives from the longitudinal X states in the AlAs layers, whereas at higher pressures the transverse X states shift to a lower energy. This crossing is clearly visible in the PL, and the shift in the transition energies is used to determine a value for the tetragonal shear deformation potential of the X point of AlAs, ΞX1, of 6.9 ± 0.6 eV. This is compared with existing estimates, and is used to confirm a value of 23 meV as the ambient pressure strain dependent splitting between the longitudinal and transverse X states. The ambient pressure confinement splitting is then investigated by using a linear extrapolation of the pressure shift in the transverse X features. This leads to the first estimation of the zero pressure state alignment from samples having a conduction band ground state of longitudinal X character, along with large confinement energies. Comparisons with the Kronig-Penney model suggest that the current value of the transverse effective mass of AlAs may need to be reassessed.

Original languageEnglish
Pages (from-to)429-434
Number of pages6
JournalJournal of Physics and Chemistry of Solids
Volume56
Issue number3-4
DOIs
StatePublished - 1995
Externally publishedYes

Bibliographical note

Funding Information:
Acknowledgements-This work was supported by the Engineering and Physical Sciences Research Council of the U.K., and by the Human Capital and Mobility Programme of the European Community.

Funding

Acknowledgements-This work was supported by the Engineering and Physical Sciences Research Council of the U.K., and by the Human Capital and Mobility Programme of the European Community.

FundersFunder number
Engineering and Physical Sciences Research Council
European Commission

    Keywords

    • A. quantum wells
    • A. semiconductors
    • C. high pressure
    • D. electronic structure

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