Tailoring thermal conductivity by engineering compositional gradients in Si1−x Ge x superlattices

TítuloTailoring thermal conductivity by engineering compositional gradients in Si1−x Ge x superlattices
Tipo de publicaciónJournal Article
Año de publicación2015
AutoresFerrando-Villalba, P, Lopeandía, AF, Alvarez, FX, Paul, B, de Tomás, C, Alonso, MI, Garriga, M, Goñi, AR, Santiso, J, Garcia, G, Rodriguez-Viejo, J
JournalNano Research
Volume8
Issue9
Páginas2833-2841
ISSN1998-0124
Keywordscomposition gradients, heat transport, SiGe superlattices, Thermal conductivity
Resumen

The transport properties of artificially engineered superlattices (SLs) can be tailored by incorporating a high density of interfaces in them. Specifically, SiGe SLs with low thermal conductivity values have great potential for thermoelectric generation and nano-cooling of Si-based devices. Here, we present a novel approach for customizing thermal transport across nanostructures by fabricating Si/Si1−x Ge x SLs with well-defined compositional gradients across the SiGe layer from x = 0 to 0.60. We demonstrate that the spatial inhomogeneity of the structure has a remarkable effect on the heat-flow propagation, reducing the thermal conductivity to ∼2.2 W·m−1·K−1, which is significantly less than the values achieved previously with non-optimized long-period SLs. This approach offers further possibilities for future applications in thermoelectricity.

URLhttp://dx.doi.org/10.1007/s12274-015-0788-9
DOI10.1007/s12274-015-0788-9
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