RSS-Beitrag

07.10.2011 - 13:46:04

Vortragsankündigung

13. Oktober 2011 um 13:00 Uhr - Prof. Dr. Gerhard Klimeck

Vortragender: Prof. Dr. Gerhard Klimeck
Network for Computational Nanotechnology, Purdue University, West Lafayette, IN 47907
Zeit: 13:00 Uhr
Raum: LTj227

Abstract:
The technological progress in dimensional scaling allows to tailor the phonons which control the heat flow in semiconductor nanostructures. Thermal management in nanostructures can vary from fast heat evacuation in MOSFETs to preventing heat flow in thermoelectric devices. Nano-scale heat management requires a thorough understanding of the basic heat flow in semiconductors. Along with experiments computer modeling and simulation are playing an increasingly vital role in exploring the numerous possibilities in materials, devices and systems. The present work applies computational physics modeling and simulations to explore the, (i) thermal, and (ii) thermoelectric properties in nano-scale semiconductors. For thermal properties the phonon dispersion in zinc-blende materials is obtained using the Modified Valence Force Field (MVFF) model. The thermal transport an d the thermoelectric properties of semiconductors are calculated using the Landauer's method. Using computer modeling and simulations the effect of strain, porosity and size on thermal and thermoelectric properties in Silicon nanowires (SiNWs) are explored. The key findings are, (a) porous Si nanowires provide a lucrative idea for enhancing the thermoelectric efficiency at room temperature, and (b) strain provides a good way of tuning the thermal properties in SiNWs. The correlation the phonon shifts from the MVFF model in Si nanowires to their shape, size and orientation benchmarked against experimental Raman spectroscopy data, enables nano-scale metrology. Atomic level manipulation holds the key to engineer the thermal properties at the nano-scale.