Impact of Phonon Surface Roughness Scattering on Thermal Conductivity of Thin Si Nanowires

Autor:	Martin, Pierre, Aksamija, Zlatan, Pop, Eric, Ravaioli, Umberto
Rok vydání:	2009
Předmět:	Condensed Matter - Other Condensed Matter Condensed Matter - Mesoscale and Nanoscale Physics
Druh dokumentu:	Working Paper
DOI:	10.1103/PhysRevLett.102.125503
Popis:	We present a novel approach for computing the surface roughness-limited thermal conductivity of silicon nanowires with diameter D < 100 nm. A frequency-dependent phonon scattering rate is computed from perturbation theory and related to a description of the surface through the root-mean-square roughness height Delta and autocovariance length L. Using a full-phonon dispersion relation, we find a quadratic dependence of thermal conductivity on diameter and roughness as (D/\Delta)^2. Computed results show excellent agreement with experimental data for a wide diameter and temperature range (25-350 K), and successfully predict the extraordinarily low thermal conductivity of 2 W.m^{-1}.K^{-1} at room temperature in rough-etched 50 nm silicon nanowires. Comment: 12 pages, 4 figures
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/0902.4735 Zobrazit plný text záznamu View this record from Arxiv