Thermal Conductivity of Silicon Nanowire by Nonequilibrium Molecular Dynamics Simulations

The thermal conductivity of the silicon nanowire was calculated using nonequilibrium molecular dynamics method. The dependence of thermal conductivity on the wire length, cross-sectional area, and temperature was investigated. The Stillinger-Weber potential model and the Nose-Hoover thermostat were used. The surfaces at the wire ends were set free boundary conditions and potential boundaries in other directions. The cross-sectional area range of the nanowires under research is from about 5 nm² to 19 nm² and the length range is from about 6 nm to 54 nm. The results agree well with experimental results. The reciprocal of thermal conductivity was found to be linear with that of nanowire length. And our results quantitatively showed that decreasing the cross-sectional area can reduce the phonon mean free path of the nanowire.