Revisiting thermal conductivity and interface conductance at the nanoscale
Résumé
A simple and easy-to-handle semi-analytical model able to describe heat transport in heterostructures of length varying from the nano to the microscale is presented. It consists in redefining three intrinsic parameters: the ballistic thermal conductance, the effective thermal conductivity, and the interface thermal conductance by using two temperatures and distinguishing the phonon populations according to the direction of their velocities instead of the standard pseudo-temperature T. The resulting model agrees well with the thermal conductance and temperature profiles predicted by advanced Monte Carlo simulation in all phonon transport regimes, i.e. diffusive, ballistic, and quasi-ballistic regimes, even in the presence of multiple interfaces. It is able to provide new insights into the interpretation of thermal properties of complex nanostructures.
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