First principles kinetic-collective thermal conductivity of semiconductors

A fully predictive kinetic-collective model using first principles phonon spectra and relaxation times is presented. Thermal conductivity values obtained for Si, Ge, C (diamond), and GaAs in a wide range of sizes and temperatures are in good agreement with experimental data without the use of any fitting parameter. These results open the door to discuss how the precise combination of kinetic and collective contributions to heat transport could provide a useful framework to interpret recent complex experiments displaying non-Fourier behavior.