Regensburg 2019 – wissenschaftliches Programm
DS 10.3: Vortrag
Montag, 1. April 2019, 17:15–17:30, H39
Phonon modes and thermal conductivity in Si/SiO2 multishell nanotubes — C. I. Isacova1, A. I. Cocemasov1, D. L. Nika1, O. G. Schmidt2, and •V. M. Fomin1,2 — 1E. P. Pokatilov Laboratory of Physics and Engineering of Nanomaterials, Moldova State University, Chisinau MD-2009, Republic of Moldova — 2Institute for Integrative Nanosciences, Leibniz IFW Dresden, Dresden D-01069, Germany
Theoretical atomistic study of thermal transport is conducted for Si/SiO2 multishell nanotubes, which model rolled-up Si/SiO2 nanostructures. Phonon modes are obtained within Lattice Dynamics Theory. Thermal conductivity in Si/SiO2 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/SiO2 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/SiO2 bilayers in multishell nanotubes. The present work is supported by the DFG grant no. FO 956/4-1.