Synthesis and thermoelectric properties of PbTe nanorods and microcubes

The pure face-centered cubic lead telluride nanorods and microcubes have been synthesized by the composite-hydroxide-mediated (CHM) approach using hydrazine and NaBH4 as a reducing agent, respectively. The method is based on reactants in hydroxide melts at a eutectic temperature of 200 °C and normal atmosphere without using an organic dispersant or surface capping agent. Scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy are used to characterize the structure, morphology, and composition of the samples. The results show that the diameter of nanorods is 40–70 nm, while the size of microcubes is up to several micrometers. The measurement of thermoelectricity shows that the room temperature Seebeck coefficient value of the nanorods is up to 679.8 μV/K, about 2.56 times larger than that of the lead telluride bulk material, while the Seebeck coefficient value of the microcubes is only 195.5 μV/K.