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ISSN Online: 2377-424X

International Heat Transfer Conference 12
August, 18-23, 2002, Grenoble, France

Heat Conduction in Si/Ge Superlattices based on Phonon Radiative Transport Approach

Get access (open in a dialog) DOI: 10.1615/IHTC12.4130
6 pages

Sinopsis

Heat conduction through a multilayered slab made of Si/Ge ultra-thin slices (10 nm) is computed by solving the phonon radiative transport approach. This approach holds when the medium size are smaller or have the same order of magnitude the mean free path of phonon in the related materials (>10 nm). Then ballistic transport of phonon prevails and transmission-reflection conditions at interfaces can be derived from Snell's law and acoustic mismatch theory. Phonon intensities are here calculated on a spectral basis by taking into account realistic extinction spectra for Si and Ge. Thus frequency confinement occurs in Si layers whose cut-off frequency is higher than in the surrounding Ge layers. Several run have been performed by using the discrete ordinate method to solve the phonon radiative transport equation. The number of two-layers periods have been increased from 2 to 50 (4 to 100 layers) and, as a limiting value, the apparent conductivity of the slab made of an infinite number of layers has been determined.