Raman scattering as a tool for the evaluation of strain in GaN/AlN quantum dots: The effect of capping
- Materials Science Institute, University of Valencia, P.O. Box 22085, 46071 Valencia (Spain)
- CEA-CNRS Group, 'Nanophysique et Semiconducteurs', DRFMC/SP2M/PSC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)
- Laboratoire des Materiaux et du Genie Physique, UMR5628 CNRS-INPG, INP Grenoble-MINATEC, 3 Parvis L. Neel, 38016 Grenoble Cedex 9 (France)
The strain state of GaN/AlN quantum dots grown on 6H-SiC has been investigated as a function of AlN capping thickness by three different techniques. On the one hand, resonant Raman scattering allowed the detection of the A{sub 1}(LO) quasiconfined mode. It was found that its frequency increases with AlN deposition, while its linewidth did not evolve significantly. Available experiments of multiwavelength anomalous diffraction and diffraction anomalous fine structure on the same samples provided the determination of the wurtzite lattice parameters a and c of the quantum dots. A very good agreement is found between resonant Raman scattering and x-ray measurements, especially concerning the in-plane strain state. The results demonstrate the adequacy of Raman scattering, in combination with the deformation potential and biaxial approximations, to determine quantitatively values of strain in GaN quantum dot layers.
- OSTI ID:
- 21052732
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 76, Issue 16; Other Information: DOI: 10.1103/PhysRevB.76.165403; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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