Phonon Transport in Si Nanostructures

This chapter develops a Monte Carlo (MC) method for solving the phonon Boltzmann transport equation (BTE) to perform more accurate heat transfer simulations in nanoscale Si devices. In order to evaluate the thermal conductivity, one can adopted one particle MC method, which enables obtaining the statistical convergence efficiently. The chapter uses the MC simulator to analyze the quasi‐ballistic phonon transport effect on the heat conduction in Si. It considers that the MC method is a good tool for studying the mixture regime between the ballistic and diffusive nature for the phonon transport. The chapter shows the realistic dispersion relation of phonons in bulk Si calculated from the adiabatic bond charge model, whose accuracy was validated through comparison with experimental neutron scattering data. The thermal conductivity of Si nanowires (SiNWs) was also calculated using the MC simulator. In nanostructures, phonons are frequently scattered at boundaries, which significantly impedes heat conduction.