Thermal conductivity of Si/Ge superlattices containing tilted interface

Abstract

The non-equilibrium molecular dynamics (NEMD) method is used to study the thermal conductivities of Si/Ge superlattices with tilted interface under different period lengths, different sample lengths, and different temperatures. The simulation results are as follows. The thermal conductivity of Si/Ge superlattices varies nonmonotonically with the increase of interface angle: when the period length is 4–8 atomic layers, the thermal conductivity for the interface angle of 45° is one order of magnitude larger than those for other interface angles, and the thermal conductivity increases linearly with the sample length increasing and decreases with the temperature increasing. However, when the period length is 20 atomic layers, the thermal conductivity is weakly dependent on sample length and temperature due to the existence of phonon localization.