Regensburg 2004 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 44: Poster II
HL 44.54: Poster
Donnerstag, 11. März 2004, 16:30–19:00, Poster A
Charge carriers in columnar nanostructures of porous GaAs and InP using micro-Raman scattering — •Pavel Prunici1, Gert Irmer1, Jochen Monecke1, and Ivan Tiginyanu2 — 1Institut für Theoretische Physik, TU Bergakademie Freiberg, Bernhard-von-Cotta-Str. 4, D-090596 Freiberg, Germany — 2Institute of Applied Physics, Technical University of Moldova, Boulevard Stefan cel Mare 168, MD-2004 Chisinau, Moldova
Raman scattering spectra of columnar nanostructures of porous GaAs and InP were investigated at room temperature and at 77 K using different laser excitation wavelengths in the visible and in the near infrared region. The samples have two layers with different porosity structures which were well characterized by scanning electron microscope. In the case of porous GaAs the cylinders have radii in the range of 50-100 nm and about 10000 nm long. The radii of the InP cylinders are in the range of 25-50 nm. The distribution of the charge carriers in individual cylinders as well as in groups of well-oriented parallel cylinders was studied using micro-Raman scattering. The bands observed are compared with calculations predicting coupled LO-phonon-plasmon and coupled Fröhlich-plasmon modes using a dielectric function derived on the basis of an appropriate two-dimensional effective-medium theory.