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The 15th International Conference on

Vibrations at Surfaces

June 22-26, 2015 ▪ Donostia-San Sebastián, Spain

Donostia Igeldotik

Invited talk

How surfaces dictate thermal transport in low-dimensional semiconductors

D. Donadio1,2

1Donostia International Physics Center (DIPC) – UPV/EHU, E-20018 San Sebastián, Spain

2IKERBASQUE, Basque Foundation for Science, E-48013, Bilbao, Spain

In non metallic solids phonons with frequencies in the Terahertz range are the main heat carriers. Thus, tuning the band structure of phonons and the scattering rates by nanoscale engineering allows one to control energy transport and dissipation. Given the relevant length scales involved in nanoscale heat transport, of the order of tens of nanometers, one cannot always treat the system as a continuum and rely on Fourier's heat equations and the atomistic structure has to be taken into account explicitly.

In this talk we unravel the effect of dimensionality reduction and the prominent role of surface structure and surface resonances in tuning thermal transport in silicon nanostructures, including ultrathin membranes [1,2] and silicon nanowires [3,4]. Large scale molecular dynamics and lattice dynamics simulations provide parameter free recipes to optimize materials for thermoelectric, nanoelectronic and phononic-related applications.

[1] S. Neogi and D. Donadio, The European Physical Journal B 88, 73 (2015)

[2] S. Neogi, J. Sebastian Reparaz, L. F. C. Pereira, B. Graczykowski, M. R. Wagner, M. Sledzinska, A. Shchepetov, M. Prunnila, J. Ahopelto, C. M. Sotomayor Torres, and D. Donadio, ACS Nano 9, 3820 (2015)

[3] D. Donadio and G. Galli, Nano Lett. 10, 847 (2010)

[4] I. Duchemin and D. Donadio, Appl. Phys. Lett. 100, 223107 (2012)