Thermal properties of nanocrystalline silicon nanobeams
Maire, Jeremie (Institut Català de Nanociència i Nanotecnologia)
Chávez Ángel, Emigdio (Institut Català de Nanociència i Nanotecnologia)
Arregui Bravo, Guillermo (Universitat Autònoma de Barcelona. Departament de Física)
Colombano Sosa, Martin (Institut Català de Nanociència i Nanotecnologia)
Capuj, Nestor Eduardo (Universidad de La Laguna. Instituto Universitario de Materiales y Nanotecnología)
Griol, Amadeu (Universitat Politècnica de València. Nanophotonics Technology Center)
Martínez, Alejandro (Universitat Politècnica de València. Nanophotonics Technology Center)
Navarro Urrios, Daniel (Institut Català de Nanociència i Nanotecnologia)
Ahopelto, Jouni (VTT Technical Research Centre of Finland Ltd)
Sotomayor Torres, Clivia M. (Institut Català de Nanociència i Nanotecnologia)

Date:	2022
Abstract:	Controlling thermal energy transfer at the nanoscale and thermal properties has become critically important in many applications since it often limits device performance. In this study, the effects on thermal conductivity arising from the nanoscale structure of free-standing nanocrystalline silicon films and the increasing surface-to-volume ratio when fabricated into suspended optomechanical nanobeams are studied. Thermal transport and elucidate the relative impact of different grain size distributions and geometrical dimensions on thermal conductivity are characterized. A micro time-domain thermoreflectance method to study free-standing nanocrystalline silicon films and find a drastic reduction in the thermal conductivity, down to values below 10 W m K is used, with a stronger decrease for smaller grains. In optomechanical nanostructures, this effect is smaller than in membranes due to the competition of surface scattering in decreasing thermal conductivity. Finally, a novel versatile contactless characterization technique that can be adapted to any structure supporting a thermally shifted optical resonance is introduced. The thermal conductivity data agrees quantitatively with the thermoreflectance measurements. This study opens the way to a more generalized thermal characterization of optomechanical cavities and to create hot-spots with engineered shapes at the desired position in the structures as a means to study thermal transport in coupled photon-phonon structures.
Grants:	European Commission 829061 European Commission 713450 Agencia Estatal de Investigación PGC2018-094490-B Agencia Estatal de Investigación PGC2018-101743-B-I00 Ministerio de Economía y Competitividad SEV-2017-0706 Ministerio de Economía y Competitividad RYC-2014-15392
Note:	Altres ajuts: this work was supported by the CERCA Programme / Generalitat de Catalunya.
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:	Characterization methods ; Free standings ; Nano beams ; Nanocrystalline silicon films ; Opto-mechanics ; Optomechanical ; Polycrystalline ; Thermal characterization ; Thermal characterization method ; Thermal conduction
Published in:	Advanced functional materials, Vol. 32, issue 4 (Jan. 2022) , art. 2105767, ISSN 1616-3028

DOI: 10.1002/adfm.202105767

10 p, 4.2 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles