Modeling semi-conductor thermal properties. The dispersion role

TL;DR

This paper models heat transport in semiconductor nanostructures using an improved phonon relaxation time model based on dispersion relations, enabling accurate predictions of silicon nanowire and nanofilm thermal properties across different regimes.

Contribution

It introduces a revised Holland model for phonon relaxation times derived from dispersion relations, enhancing thermal property predictions in semiconductor nanostructures.

Findings

Recalculated phonon relaxation times match bulk silicon and germanium.

Predicted thermal conductivities for silicon nanowires and nanofilms.

Model accurately captures ballistic and mesoscopic heat transport regimes.

Abstract

We study heat transport in semiconductor nanostructures by solving the Boltzmann Transport Equation (BTE) by means of the Discrete Ordinate Method (DOM). Relaxation time and phase and group velocitiy spectral dependencies are taken into account. The Holland model of phonon relaxation time is revisited and recalculated from dispersion relations (taken in litterature) in order to match bulk silicon and germanium values. This improved model is then used to predict silicon nanowire and nanofilm thermal properties in both ballistic and mesoscopic regimes.