Increase of Thermal Resistance Between a Nanostructure and a Surface due to Phonon Multireflections

TL;DR

This paper demonstrates that phonon multireflections at the interface significantly increase thermal resistance between nanostructures and surfaces, challenging previous models and providing a new general expression for contact resistance.

Contribution

It introduces a new model accounting for phonon multireflections, showing their impact on thermal resistance and deriving a simple expression for contact resistance.

Findings

Multireflections significantly increase thermal resistance.

The increase depends on nanostructure shape and phonon mean free path.

Derived a general expression for contact resistance.

Abstract

The thermal resistance between a nanostructure and a half-body is calculated in the framework of particle-phonons physics. The current models approximate the nanostructure as a thermal bath. We prove that the multireflections of heat carriers in the nanostructure significantly increase resistance in contradiction with former predictions. This increase depends on the shape of the nanostructure and the heat carriers mean free path only. We provide a general and simple expression for the contact resistance and examine the specific cases of nanowires and nanoparticles.