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HL: Halbleiterphysik

HL 43: III-V Halbleiter II

HL 43.3: Vortrag

Donnerstag, 11. März 2004, 15:45–16:00, H14

Determination of the nitrogen distribution in GaInNAs/GaAs quantum wells by transmission electron microscopy and correlation with spectroscopic data — •M. Hetterich¹, A. Grau¹, D. Litvinov², A. Rosenauer², D. Gerthsen², Ph. Gilet³, and L. Grenouillet³ — ¹Institut für Angewandte Physik and Center for Functional Nanostructures (CFN), Universität Karlsruhe, D-76131 Karlsruhe, Germany — ²Laboratorium für Elektronenmikroskopie and CFN, Universität Karlsruhe, Germany — ³LETI/DOPT/SLIR, CEA-Grenoble, 38054 Grenoble cedex 9, France

We report on a new technique for the determination of the nitrogen concentration in GaInNAs heterostructures by transmission electron microscopy and correlate the obtained results with spectroscopic data (temperature-dependent photoluminescence and photoreflectance spectroscopy). Two almost identical samples grown by gas-source molecular beam epitaxy on GaAs (001) were investigated, containing InGaAs and GaInNAs quantum wells, respectively. Both samples had the same nominal well thickness and In concentration. They only differed in the nitrogen content. The In concentration profile of the InGaAs/GaAs quantum wells was determined by composition evaluation of lattice fringe analysis (CELFA) based on the chemical sensitivity of the (002) reflection in the zincblende structure. The N concentration in the GaInNAs wells was then evaluated by the comparison of CELFA results obtained for both samples. The presented technique may be useful for future investigations into the mechanisms behind the influence of annealing on the optical properties of GaInNAs quantum wells.