Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 12: Poster I

HL 12.10: Poster

Montag, 8. März 2004, 16:30–19:00, Poster A

Optical properties of Zn_1−xMn_xSe studied by spectroscopic ellipsometry — •J. Kvietkova¹, B. Daniel¹, M. Hetterich¹, M. Schubert², D. Spemann², D. Litvinov³, and D. Gerthsen³ — ¹Institut für Angewandte Physik and Center for Functional Nanostructures (CFN), Universität Karlsruhe, D-76131 Karlsruhe — ²Institut für Experimentelle Physik II, Fakultät für Physik und Geowissenschaften, Universität Leipzig, D-04103 Leipzig — ³Laboratorium für Elektronenmikroskopie and CFN, Universität Karlsruhe, D-76128 Karlsruhe

The ternary diluted magnetic semiconductor ZnMnSe is a suitable candidate for the use in optoelectronic devices either as a spin aligner or a waveguide layer. We study the optical properties of cubic Zn_1−xMn_xSe thin films grown on GaAs (001) substrates by molecular-beam epitaxy. We present the complex dielectric function obtained by variable-angle spectroscopic ellipsometry in the photon energy range from 0.75 to 4.5 eV using the point-by-point inversion approach. A critical-point parametric model was employed to fit the experimental data for photon energies between 0.75 and 3.3 eV, which led to an excellent agreement. The best-fit model calculation parameters are given for ZnSe as well as for Mn contents of 13.6% and 21%. The below-band-gap index of refraction is well represented by a simple Cauchy dispersion formula.