Home > Articles > Published articles > Thermal conductivity and air-mediated losses in periodic porous silicon membranes at high temperatures |
Date: | 2017 |
Abstract: | Heat conduction in silicon can be effectively engineered by means of sub-micrometre porous thin free-standing membranes. Tunable thermal properties make these structures good candidates for integrated heat management units such as waste heat recovery, rectification or efficient heat dissipation. However, possible applications require detailed thermal characterisation at high temperatures which, up to now, has been an experimental challenge. In this work we use the contactless two-laser Raman thermometry to study heat dissipation in periodic porous membranes at high temperatures via lattice conduction and air-mediated losses. We find the reduction of the thermal conductivity and its temperature dependence closely correlated with the structure feature size. On the basis of two-phonon Raman spectra, we attribute this behaviour to diffuse (incoherent) phonon-boundary scattering. Furthermore, we investigate and quantify the heat dissipation via natural air-mediated cooling, which can be tuned by engineering the porosity. |
Grants: | European Commission 309150 European Commission 604668 Ministerio de Ciencia e Innovación CSD2010-0044 Ministerio de Economía y Competitividad FIS2015-70862-P Ministerio de Economía y Competitividad SEV-2013-0295 |
Rights: | Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original. |
Language: | Anglès |
Document: | Article ; recerca ; Versió publicada |
Subject: | Nanoscale materials ; Thermodynamics |
Published in: | Nature communications, Vol. 8 (September 2017) , art. 415, ISSN 2041-1723 |
9 p, 1.4 MB |