  We study heat transport in semiconductor nanostructures by solving the
Boltzmann Transport Equation (BTE) by means of the Discrete Ordinate Method
(DOM). Relaxation time and phase and group velocitiy spectral dependencies are
taken into account. The Holland model of phonon relaxation time is revisited
and recalculated from dispersion relations (taken in litterature) in order to
match bulk silicon and germanium values. This improved model is then used to
predict silicon nanowire and nanofilm thermal properties in both ballistic and
mesoscopic regimes.
