We investigated how dimensionality affects heat transport in Si-Ge superlattices by computing the thermal conductivity of planar superlattices and arrays of Ge nanowires and nanodots embedded in Si. We studied superlattices with ∼10 nm periods using a fully atomistic Monte Carlo solution of the Boltzmann transport equation in the relaxation time approximation. We found that for periods larger than 4 nm, the room temperature cross-plane conductivity of planar superlattices with equally thick Si and Ge layers is larger than that of their nanowire and dot counterparts of similar sizes (up to 100\%), while the trend is reversed below 4 nm.
@article{arxiv.1903.09855,
title = {Dimensionality and heat transport in Si-Ge superlattices},
author = {Ivana Savić and Davide Donadio and Francois Gygi and Giulia Galli},
journal= {arXiv preprint arXiv:1903.09855},
year = {2019}
}