Thermal transport in composition graded silicene/germanene heterostructures

Abstract

Through equilibrium and non-equilibrium molecular dynamics simulations, we have demonstrated the inhibitory effect of composition graded interface on thermal transport behavior in lateral heterostructures. Specifically, we investigated the influence of composition gradient length and heterogeneous particles at the silicene/germanene (SIL/GER) heterostructure interface on heat conduction. Our results indicate that composition graded interface at the interface diminishes the thermal conductivity of the heterostructure, with a further reduction observed as the length increases, while the effect of the heterogeneous particles can be considered negligible. To unveil the influence of composition graded interface on thermal transport, we conducted phonon analysis and identified the presence of phonon localization within the interface composition graded region. Through these analyses, we have determined that the decrease in thermal conductivity is correlated with phonon localization within the heterostructure, where a stronger degree of phonon localization signifies poorer thermal conductivity in the material. Our research findings not only contribute to understanding the impact of interface gradient-induced phonon localization on thermal transport but also offer insights into the modulation of thermal conductivity in heterostructures.