Thermal transport in SiGe superlattice thin films and nanowires: Effects of specimen and periodic lengths

Keng-Hua Lin, Purdue University
Alejandro Strachan, Birck Nanotechnology Center, Purdue University

Date of this Version

3-4-2013

Citation

Phys. Rev. B 87, 115302 – Published 4 March 2013

Comments

This is the published version of Keng-Hua Lin and Alejandro Strachan. 4 March 2013. Thermal transport in SiGe superlattice thin films and nanowires: Effects of specimen and periodic lengths. First published in the Physical Review B and is available online at: https://doi.org/10.1103/PhysRevB.87.115302

Abstract

We compute the thermal conductivity of superlattice (SL) thin films and nanowires for various SL periods and total specimen lengths using nonequilibrium molecular dynamics. Both types of materials exhibit similar behaviors with respect to SL period but the thermal conductivity of the thin films exhibits a significantly higher sensitivity to the specimen length. Notably, the thermal conductivity of SL thin films is smaller than those of the corresponding nanowires for specimen lengths below approximately 35 nm. These results arise from the complex dependence of the conductivities of the interfaces and the SL components on the specimen size and period. These trends and observations are explained using a simple phonon model that builds on the relationship between the cumulative thermal conductivity and the phonon wavelength. DOI: 10.1103/PhysRevB.87.115302

Discipline(s)

Nanoscience and Nanotechnology

 

Share