Jump to main content
Jump to site search

Issue 6, 2016
Previous Article Next Article

Tensile strains give rise to strong size effects for thermal conductivities of silicene, germanene and stanene

Author affiliations

Abstract

Based on first principles calculations and self-consistent solution of the linearized Boltzmann–Peierls equation for phonon transport approach within a three-phonon scattering framework, we characterize lattice thermal conductivities k of freestanding silicene, germanene and stanene under different isotropic tensile strains and temperatures. We find a strong size dependence of k for silicene with tensile strain, i.e., divergent k with increasing system size; however, the intrinsic room temperature k for unstrained silicene converges with system size to 19.34 W m−1 K−1 at 178 nm. The room temperature k of strained silicene becomes as large as that of bulk silicon at 84 μm, indicating the possibility of using strain in silicene to manipulate k for thermal management. The relative contribution to the intrinsic k from out-of-plane acoustic modes is largest for unstrained silicene, ∼39% at room temperature. The single mode relaxation time approximation, which works reasonably well for bulk silicon, fails to appropriately describe phonon thermal transport in silicene, germanene and stanene within the temperature range considered. For large samples of silicene, k increases with tensile strain, peaks at ∼7% strain and then decreases with further strain. In germanene and stanene, increasing strain hardens and stabilizes long wavelength out-of-plane acoustic phonons, and leads to similar k behaviors to those of silicene. These findings further our understanding of phonon dynamics in group-IV buckled monolayers and may guide transfer and fabrication techniques for these freestanding samples and engineering of k by size and strain for applications of thermal management and thermoelectricity.

Graphical abstract: Tensile strains give rise to strong size effects for thermal conductivities of silicene, germanene and stanene

Back to tab navigation

Supplementary files

Article information


Submitted
21 Nov 2015
Accepted
11 Jan 2016
First published
11 Jan 2016

Nanoscale, 2016,8, 3760-3767
Article type
Paper

Tensile strains give rise to strong size effects for thermal conductivities of silicene, germanene and stanene

Y. D. Kuang, L. Lindsay, S. Q. Shi and G. P. Zheng, Nanoscale, 2016, 8, 3760
DOI: 10.1039/C5NR08231E

Social activity

Search articles by author

Spotlight

Advertisements