Effects of transverse geometry on the thermal conductivity of Si and Ge nanowires

TL;DR

This study investigates how the transverse geometry, including polygonal, tubular, and core/shell structures, influences the thermal conductivity of silicon and germanium nanowires using molecular dynamics simulations.

Contribution

It provides a comparative analysis of various nanowire geometries and their impact on thermal transport properties, highlighting the role of transverse shape and core/shell configurations.

Findings

Polygonal cross sections affect thermal conductivity.

Tubular nanowires show different heat transport behavior.

Core/shell structures have distinct thermal properties.

Abstract

We explore the effects of geometry on the thermal conductivity (kappa) of silicon and germanium nanowires, with lengths between 10-120 nm and diameters up to 5-6 nm. To this end we perform molecular dynamics simulations with the LAMMPS software, using Tersoff interatomic potentials. We consider nanowires with polygonal cross section and we discuss the effect of the transverse geometry on the thermal conductivity. We also consider tubular (hollow) nanowires and core/shell combinations of Si/Ge and Ge/Si, and we compare the heat transport of the core/shell structure with that of the separated core and shell components.