Thermal transport in Bi2Te3-PbTe segmented thermoelectric nanofilms

• The interfacial bonding, the ordering of the interfacial structures, etc., affect the interfacial energy transport. • Bi 2 Te 3 -PbTe nanofilms have ultra-low thermal conductivity (between 0.24 and 0.55 W/mK) at temperatures of 300 K and 700 K. • Among all studied models, Bi 2 Te 3 [110]-PbTe[100] has the lowest thermal contact resistance. By using molecular dynamic simulations, we explore the thermal transport of Bi 2 Te 3 -PbTe nanofilms with interfaces formed by different crystal orientations. We reveal that the interfacial bonding density and the ordering of the interfacial structures are important to the thermal contact resistance. The thermal contact resistance of Bi 2 Te 3 [110]-PbTe[100] was found to be lower than that of Bi 2 Te 3 [210]-PbTe[100] and Bi 2 Te 3 [111]-PbTe[100] nanofilms. The obtained results suggest that the Bi 2 Te 3 -PbTe superlattice nanofilms bear ultra-low thermal conductivity at both 300 K and 700 K. Our study should shed light on the atomistic design of highly efficient segmented thermoelectric devices.