Dresden 2011 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 39: Computational Materials Modelling V

MM 39.7: Vortrag

Donnerstag, 17. März 2011, 17:45–18:00, IFW A

A molecular dynamics approach to simulate Raman and IR spectra in silicon nanowires — Felix Zörgiebel, •Jens Kunstmann, Daijiro Nozaki, and Gianaurelio Cuniberti — Insitute for Materials Science and Max Bergmann Center of Biomaterials, TU Dresden, 01062 Dresden, Germany

We developed a method to filter phonons from molecular dynamics (MD) simulations based on a density functional tight binding approach. We are able to extract phonon frequencies, polarizations, and q-vectors. Our results for silicon bulk and silicon nanowires show good agreement with experimental data and exceed the accuracy and applicability of the Hesse matrix approach. In particular we are able to determine phonon occupations and temperature effects. Furthermore we filtered Raman, Infrared, and silent modes from MD trajectories via symmetry analysis. This enables us to predict Raman and Infrared spectra of silicon nanowires and explain their origin in terms of phonon polarizations.