# Regensburg 2019 – wissenschaftliches Programm

## Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

# DS: Fachverband Dünne Schichten

## DS 10: Thermoelectric and Phase Change Materials

### DS 10.3: Vortrag

### Montag, 1. April 2019, 17:15–17:30, H39

**Phonon modes and thermal conductivity in Si/SiO**_{2}** multishell nanotubes** — C. I. Isacova^{1}, A. I. Cocemasov^{1}, D. L. Nika^{1}, O. G. Schmidt^{2}, and •V. M. Fomin^{1,2} — ^{1}E. P. Pokatilov Laboratory of Physics and Engineering of Nanomaterials, Moldova State University, Chisinau MD-2009, Republic of Moldova — ^{2}Institute for Integrative Nanosciences, Leibniz IFW Dresden, Dresden D-01069, Germany

Theoretical atomistic study of thermal transport is conducted for Si/SiO_{2} multishell nanotubes, which model rolled-up Si/SiO_{2} nanostructures. Phonon modes are obtained within Lattice Dynamics Theory. Thermal conductivity in Si/SiO_{2} nanotubes, as calculated using Boltzmann Transport Equation within the relaxation-time approximation, is lower than that in Si nanowires with the same lateral dimensions due to the acoustical mismatch of the materials and a stronger phonon confinement. A large number of phonon modes are scattered on Si/SiO_{2} interfaces, what enhances the effect of the boundary scattering mechanism on thermal conductivity of multishell nanotubes. Thermal conductivity is found to decrease almost linearly as a function of the number of Si/SiO_{2} bilayers in multishell nanotubes. The present work is supported by the DFG grant no. FO 956/4-1.