Issue |
Ann. Phys. Fr.
Volume 13, Number 6, 1988
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Page(s) | 597 - 622 | |
DOI | https://doi.org/10.1051/anphys:01988001306059700 | |
Published online | 01 June 2004 |
Superlattice and disorder effects on vibrations in III-V compounds
CNET, Laboratoire de Bagneux, 196, Avenue Henri-Ravera 92220 Bagneux, France
We analyse the perturbation induced either by a random atomic distribution (mixed crystal) or a one-dimensional periodic one (superlattice) onto the vibrations in III-V compounds and in particular onto the Raman backscattering active modes. As a consequence of the induced relaxation of the wavevector selection rule; some new modes become Raman active. We analyse their frequency and activity as a function of respectively the alloy concentration and the thicknesses of layers constituting the superlattice. We illustrate these results on structures based on the GaAs and AlAs compounds.
Résumé
Nous analysons la perturbation induite par une distribution atomique aléatoire (alliage) ou modulée périodiquement suivant une direction cristalline (superréseau) sur la dynamique de réseau des semiconducteurs III-V et sur les spectres de rétrodiffusion Raman correspondants. La relaxation de la loi de conservation du vecteur d'onde qui résulte de telles distributions permet l'observation de nouveaux modes en diffusion Raman. Nous analysons leurs fréquence et activité en fonction respectivement de la composition de l'alliage ou des paramètres structuraux du superréseau. Nous illustrons ces résultats dans le cas de structures à base des composés GaAs et AlAs.
PACS: 6320 – Phonons and vibrations in crystal lattices / 7830G – Infrared and Raman spectra in inorganic crystals / 7865J – Optical properties of nonmetallic thin films / 6865 – Low dimensional structures: growth, structure and nonelectronic properties / 6830 – Dynamics of solid surfaces and interface vibrations
Key words: aluminium compounds / crystal surface and interface vibrations / gallium arsenide / III V semiconductors / Raman spectra of inorganic solids / semiconductor superlattices / superlattice effects / disorder effects / vibrations / III V compounds / perturbation / random atomic distribution / mixed crystal / Raman backscattering active modes / induced relaxation / wavevector selection rule / frequency / activity / alloy concentration / thicknesses / GaAs / AlAs
© EDP Sciences, 1988