Heat transport in silicon nanoporous structures with phonon wave guides

Abstract

Abstract In recent years, studies on porous nanostructures have shown the topological structure of porous material has an important effect on heat flow control. However, for porous structures, the complexity of geometry brings great difficulties to the study of phonon transport behaviors. Especially, phonon mean free path (MFP) can no longer be calculated just by approximate structural simplifications. In this work, we applied the Monte Carlo method to estimate phonon geometric MFP of three-dimensional nanostructures and analyzed phonon transport behaviors in the nanostructures. A specific compound structure composed of a cubic porous base and a phonon waveguide was proposed to improve thermal management, the dependencies of thermal conductivities on different porosities, pore radiuses and inclination angles were studied. The results show thermal fluxes can be tuned not only by changing porosities or pore radiuses but also by modulating the inclination angles of the compound structures.