Regensburg 2002 – wissenschaftliches Programm
HL 38.23: Poster
Donnerstag, 14. März 2002, 16:30–19:00, Poster A
Fröhlich mode in GaN columnar nanostructures — •G. Irmer1, J. Monecke1, I.M. Tiginyanu2, A. Sarua2, S.M. Hubbard3, D. Pavlidis3, and V. Valiaev3 — 1Institut für Theoretische Physik, Technische Universität Bergakademie Freiberg — 2Laboratory of Low-Dimensional Semiconductor Structures, Institute of Applied Physics, Technical University of Moldova, 2004 Chisinau, Moldova — 3Department of Electrical Engineering and Computer Science, The University of Michigan, Ann Arbor, MI 48109-2122, USA
GaN columnar nanostructures fabricated by electrochemical dissolution of bulk material have been studied by micro-Raman spectroscopy. The anodization induces an increase in the intensity of Raman scattering accompanied by a breakdown of the polarization selection rules and by the appearance of a new mode at 716 cm− 1, i.e. in the frequency gap between the transverse optical and longitudinal-optical bulk phonons. We present a Raman line-shape analysis based on the effective dielectric function of a composite that brings to light the Fröhlich character of this mode.