Broadly manipulating the interfacial thermal energy transport across the Si/4H-SiC interfaces via nanopatterns

Abstract

Manipulating the thermal transport across the interfaces via nanostructuring is critical for thermal management in electronics and energy conversion in thermoelectrics. Recent experiments have enabled the fabrication of controllable nanopatterns at interfaces, and therefore provide a new perspective to design and manipulate interfacial heat transfer. By performing nonequilibrium molecular dynamics simulations, we reported that the interfacial thermal conductance of Si/4H-SiC interfaces can be modulated broadly from ∼ 300 MW/m2K to ∼ 1000 MW/m2K by confining nanopatterns with a thickness on the order of nanometers, i.e., smaller than 30 nm. Based on the spectral heat current and participation ratio analysis, the nonmonotonic nanopattern section-dependent thermal conductance as observed in our simulations was found to be originated from two competing mechanisms, i.e., phonon-boundary scattering and interfacial phonon transport channels. The corresponding interfacial thermal conductance initially decreased with the nanopattern section when the phonon-boundary scattering is dominant and became stronger, and then increased when there were many more possible interfacial phonons transport channels. The thermal conductance was enhanced by ∼11% compared to that of the bare Si/4H-SiC interface once the latter mechanism was dominant. Besides, the thermal resistance induced by the pattern itself becomes evident and must be considered when the height of the nanopattern becomes greater. Our work here provides a comprehensive investigation on manipulating the thermal transport across the interfaces via controllable nanopatterns, which is important and meaningful for designing and optimizing the advanced thermal interface materials.