Temperature Enhancement Through Interaction of Thermal Waves for Phonon Transport in Silicon Thin Films.

Recently, Siemens et al. found that the Fourier law may overestimate the energy transported away from one hot spot in the thin film. In this work, the lattice Boltzmann method is employed to investigate phonon transport in silicon thin films. It is found that in the transitional or ballistic regime when the thermal waves initiated from temperature disturbances on two surfaces of the thin film meet in the inner region, the temperature rises significantly, which is different from the case when the heat conduction is induced by the temperature disturbance on one surface of the thin film. Therefore, the interaction of thermal waves induced by the thermal transport from two nanoscale hot spots separated by a nanoscale distance inside the thin film may temporarily cause a higher temperature in some regions between the two hot spots than that predicted by the Fourier law. [ABSTRACT FROM AUTHOR]