Thermal Conductivity of Segmented Nanowires

TL;DR

This paper reviews how segmented nanowires, especially silicon and silicon/germanium types, exhibit reduced phonon thermal conductivity due to phonon spectrum modifications, with implications for thermoelectric energy applications.

Contribution

It provides a comprehensive review of theoretical results on phonon thermal conductivity in segmented nanowires, highlighting the effects of structural modifications on heat transfer.

Findings

Segmentation leads to strong reduction in phonon thermal conductivity.

Phonon spectrum modification causes phonon trapping and heat transfer suppression.

Potential applications in thermoelectric energy generation are discussed.

Abstract

We present a review of the phonon thermal conductivity of segmented nanowires focusing on theoretical results for Si and Si/Ge structures with the constant and periodically modulated cross-sections. We describe the use of the face-centered cubic cell and Born-von Karman models of the lattice vibrations for calculating the phonon energy spectra in the segmented nanowires. Modification of the phonon spectrum in such nanostructures results in strong reduction of the phonon thermal conductivity and suppression of heat transfer due to a trapping of phonon modes in nanowire segments. Possible practical applications of segmented nanowires in thermoelectric energy generation are also discussed.