Atomistic origin of the reduced lattice thermal conductivity of silicon nanotubes

Understanding the effect of edge relaxation in nanotubes (NTs) with two kinds of surfaces has been of central importance in the exploration thermal transportation properties for their applications in thermoelectric energy harvesting and heat management in nanoelectronics. In order to pursue a quantitative description of thermal transportation of SiNTs, we propose a theoretical model to deal with the lattice thermal conductivity by taking into account the sandwiched configurations based on the atomic-bond-relaxation correlation mechanism. It is found that the lattice thermal conductivity can be effectively tuned by different types of surface effect in Si nanostructures. As comparable to the Si nanowires and nanofilms, the SiNTs have the lowest thermal conductivity under identical conditions.