Details

Autor(en) / Beteiligte

• Ferrando-Villalba, Pablo
• Lopeandía, Aitor F.
• Alvarez, Francesc Xavier
• Paul, Biplab
• de Tomás, Carla
• Alonso, Maria Isabel
• Garriga, Miquel
• Goñi, Alejandro R.
• Santiso, Jose
• Garcia, Gemma
• Rodriguez-Viejo, Javier

Titel

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

Ist Teil von

• Nano research, 2015-09, Vol.8 (9), p.2833-2841

Ort / Verlag

Beijing: Springer Nature B.V

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• 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−xGex 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.