REDUCTION OF PHONON THERMAL CONDUCTIVITY IN Si/Ge NANOWIRES

Калина ИСАКОВА Молдавский государственный университет

Abstract

In this work phonon heat flux in Si and Si/Ge segmented nanowires has been theoretically investigated. The phonon energy spectra were calculated in the framework of the face-centered cubic cell model of the lattice dynamics. The phonon thermal conductivity was calculated using Boltzmann transport equation. Increasing of phonon localization due to energy spectra redistribution results in suppression of the phonon thermal flux in these nanowires as compared to the generic nanowires. As a result the drop of the phonon thermal conductivity in the large temperature range is predicted for Si/Ge segmented nanowires. These results indicate that segmented nanowires are perspective candidates for thermoelectric applications. Keywords: phonons, segmented nanowires, silicon, thermal conductivity.