Dresden 2011 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 43: Poster II: Thin Film Chalcogenide Photovoltaics; Thermoelectric Materials, Thin Films, and Nanostructures

DS 43.10: Poster

Mittwoch, 16. März 2011, 15:00–17:30, P2

Reduction of the Lattice Thermal Conductivity in One-Dimensional Quantum Dot Superlattices due to Phonon Filtering — Denis L. Nika¹, Evghenii P. Pokatilov¹, Alexander A. Balandin², Vladimir M. Fomin³, •Armando Rastelli³, and Oliver G. Schmidt³ — ¹Laboratory PMSMM, Department of Theoretical Physics, Moldova State University, MD-2009 Chisinau, Republic of Moldova — ²Nano-Device Laboratory, Department of Electrical Engineering, University of California–Riverside, CA 92521 Riverside, U.S.A. — ³Institute for Integrative Nanosciences, IFW-Dresden, D-01069 Dresden, Germany

One-dimensional quantum-dot superlattices (1D-QDS) consisting of acoustically mismatched materials Si/Ge, Si/plastic, Si/SiO₂ and Si/SiC are shown to possess sub-1 W m⁻¹K⁻¹ thermal conductivity in a temperature range from 50 K to 400 K. The phonon energy spectra are calculated in the framework of the molecular dynamic Face-centered Cubic Cell model. A significant reduction of the lattice thermal conductivity in 1D-QDS structures in comparison with homogeneous rectangular Si quantum wires is explained by the fact that the 1D-QDS structures act as effective phonon filters eliminating a significant number of phonons from thermal transport. The work was supported by the IB BMBF Project MDA 09/007 and ASM-BMBF Project 10.820.05.02GA.