Details

Autor(en) / Beteiligte

• Martin, Pierre
• Aksamija, Zlatan
• Pop, Eric
• Ravaioli, Umberto

Titel

Impact of phonon-surface roughness scattering on thermal conductivity of thin si nanowires

Ist Teil von

• Physical review letters, 2009-03, Vol.102 (12), p.125503-125503, Article 125503

Ort / Verlag

United States

Erscheinungsjahr

2009

Quelle

PROLA - Physical Review Online Archive

Beschreibungen/Notizen

• 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.