Study of phonon transport across several Si/Ge interfaces using full-band phonon Monte Carlo simulation

TL;DR

This paper introduces a full-band Monte Carlo simulation method to analyze phonon transport across Si/Ge interfaces, covering all regimes from ballistic to diffusive, and provides a new way to estimate thermal conductivities and interface effects.

Contribution

A novel full-band Monte Carlo simulator for phonon transport that captures all regimes without assumptions, applied to Si/Ge heterostructures at various scales.

Findings

The simulator accurately models phonon transport from ballistic to diffusive regimes.

It enables estimation of thermal conductivities and interface effects in Si/Ge heterostructures.

Results show scale-dependent phonon transmission characteristics.

Abstract

A Full Band Monte Carlo simulator has been developed to consider phonon transmission across interfaces that are perpendicular to the heat flux. This solver of the Boltzmann transport equation which does not require any assumption on the shape the phonon distribution can naturally consider all phonon transport regimes from the diffusive to the fully ballistic regime. Hence, this simulator is used to study single and double Si/Ge heterostructures from the micrometer scale down to the nanometer scale i.e. in all phonon transport regime from ballistic to fully diffusive. A methodology to estimate the thermal conductivities and the thermal interfaces is presented.