A novel contactless technique for thermal field mapping and thermal conductivity determination : two-laser Raman thermometry
Reparaz, Juan Sebastian (Institut Català de Nanociència i Nanotecnologia)
Chávez Ángel, Emigdio (Universitat Autònoma de Barcelona. Departament de Física)
Wagner, Markus R. (Institut Català de Nanociència i Nanotecnologia)
Graczykowski, Bartlomiej (Institut Català de Nanociència i Nanotecnologia)
Gomis-Bresco, Jordi (Institut Català de Nanociència i Nanotecnologia)
Alzina, Francesc (Institut Català de Nanociència i Nanotecnologia)
Sotomayor Torres, Clivia M. (Institut Català de Nanociència i Nanotecnologia)

Date:	2014
Abstract:	We present a novel contactless technique for thermal conductivity determination and thermal field mapping based on creating a thermal distribution of phonons using a heating laser, while a second laser probes the local temperature through the spectral position of a Raman active mode. The spatial resolution can be as small as 300 nm, whereas its temperature accuracy is ±2 K. We validate this technique investigating the thermal properties of three free-standing single crystalline Si membranes with thickness of 250, 1000, and 2000 nm. We show that for two-dimensional materials such as free-standing membranes or thin films, and for small temperature gradients, the thermal field decays as T(r) ∝ ln(r) in the diffusive limit. The case of large temperature gradients within the membranes leads to an exponential decay of the thermal field, T ∝ exp[ − A·ln(r)]. The results demonstrate the full potential of this new contactless method for quantitative determination of thermal properties. The range of materials to which this method is applicable reaches far beyond the here demonstrated case of Si, as the only requirement is the presence of a Raman active mode.
Grants:	European Commission 318352 European Commission 318117 European Commission 309150 European Commission 270789-2 Ministerio de Ciencia e Innovación MAT2012-31392 Ministerio de Ciencia e Innovación CSD2010-0044
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Contactless technique ; Free standing membranes ; Raman active modes ; Single-crystalline ; Spatial resolution ; Temperature accuracies ; Thermal distributions ; Two-dimensional materials
Published in:	Review of Scientific Instruments, Vol. 85, issue 3 (March 2014) , art. 34901, ISSN 1089-7623

DOI: 10.1063/1.4867166

6 p, 1.6 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