Thermal transport in porous Si nanowires from approach-to-equilibrium molecular dynamics calculations
Cartoixà Soler, Xavier (Universitat Autònoma de Barcelona. Departament d'Enginyeria Electrònica)
Dettori, Riccardo (Università degli Studi di Cagliari. Dipartimento di Fisica)
Melis, Claudio (Università degli Studi di Cagliari. Dipartimento di Fisica)
Colombo, Luciano (Università degli Studi di Cagliari. Dipartimento di Fisica)
Rurali, Riccardo (Institut de Ciència de Materials de Barcelona)

Date:	2016
Abstract:	We study thermal transport in porous Si nanowires (SiNWs) by means of approach-to-equilibrium molecular dynamics simulations. We show that the presence of pores greatly reduces the thermal conductivity, κ, of the SiNWs as long mean free path phonons are suppressed. We address explicitly the dependence of κ on different features of the pore topology-such as the porosity and the pore diameter-and on the nanowire (NW) geometry-diameter and length. We use the results of the molecular dynamics calculations to tune an effective model, which is capable of capturing the dependence of κ on porosity and NW diameter. The model illustrates the failure of Matthiessen's rule to describe the coupling between boundary and pore scattering, which we account for by the inclusion of an additional empirical term.
Grants:	Ministerio de Economía y Competitividad FIS2012-37549-C05-02 Ministerio de Economía y Competitividad MAT2013-40581-P Ministerio de Economía y Competitividad TEC2012-31330 Ministerio de Economía y Competitividad TEC2015-67462-C2-1-R Ministerio de Economía y Competitividad SEV-2013-0295 Ministerio de Economía y Competitividad SEV-2015-0496 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-301 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR 384
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Thermal conductivity ; Surface scattering ; Nanowires ; Thermal models ; Thermoelectric effects
Published in:	Applied physics letters, Vol. 109, Issue 1 (Jul. 2016) , p. 131071-131074, ISSN 1077-3118

DOI: 10.1063/1.4955038

Post-print 18 p, 3.0 MB

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