Abstract
Results of a systematic set of micro-Raman experiments on the changes in the line shape of the one-phonon band in Si nanowires with laser flux are presented. A complicated dependence of the Raman band asymmetry with is observed that depends both on the nanowire diameter and on the thermal anchoring of the wires to an indium foil substrate. With increasing power density in a focal spot common to micro-Raman spectroscopy, we see a clear growth in that has nothing to do with phonon confinement. In fact, we can explain the complex changes in by extending the model [H. Richter, Z. P. Wang, and Y. Ley, Solid State Commun. 39, 625 (1981)] to include an inhomogeneous heating in the Raman volume. The effects we observe in Si nanowires should be common to all semiconducting nanostructures and underscores the importance of demonstrating a flux-independent line shape when studying pure phonon confinement effects by Raman scattering.
1 More- Received 12 May 2005
DOI:https://doi.org/10.1103/PhysRevB.73.155333
©2006 American Physical Society