Controllable synthesis and thermoelectric transport properties of binary-phased PbTe/PbSe nanocrystals

Abstract

Hierarchical PbTe/PbSe materials with both well-defined primary microstructures and well-ordered secondary nanostructures have been fabricated via a facile solvothermal method. The crystallinity, morphology, structural characteristics, and compositions of as-prepared PbTe/PbSe materials are carefully studied. The obtained hierarchical binary-phased PbTe/PbSe micropeonies present high electrical conductivity and thermopower (Seebeck coefficient) in the temperature range of 300–600 K compared with the pure PbTe nanocrystals with the sizes less than 100 nm. Moreover, the morphology and properties of the composite can be tuned by adjusting the ratio of PbTe and PbSe. These delicately designed PbSe/PbTe nanoscale architectures offer tunable compositions and nano-interfaces in PbSe/PbTe heterostructures, which are the critical factors in controlling the thermoelectrical properties for applications in thermoelectric devices.