Hydrothermal synthesis and thermoelectric transport property of PbS-PbTe core-shell heterostructures

We report a facile hydrothermal route for the synthesis of PbS-PbTe core-shell heterostructured nanorods. The phase ratio of PbS to PbTe can be tuned by introducing different molar ratios of PbS to the Te precursor (molar ratio of PbS to Te precursor, R). The as-prepared samples were characterized by the X-ray diffraction pattern (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and X-ray photoelectron spectroscopy (XPS). Thermoelectric transport measurements present that the obtained PbS-PbTe core-shell nano-structured composites have an enhanced power factor compared to that of pure PbS. The maximum power factor of 294 μW (m K²)^-1 can be achieved for the sample with R = 20. In addition, the power factor can be tuned by changing the phase ratio of PbS to PbTe.