Hydrothermal synthesis and thermoelectric transport properties of Sb2Te3–Te heterogeneous nanostructures

Abstract

Sb2Te3–Te barbell-like heterogeneous nanostructures (HNs) composed of single-crystalline Sb2Te3 nanoplates and Te nanorods have been fabricated via a facile hydrothermal approach. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and scanning TEM (STEM). The barbell-like heterogeneous nanostructures can be synthesized by properly tuning the reaction time, temperature and the molar ratio of the reactants. Based on a series of contrast experiments, the probable epitaxial growth process that Sb2Te3 nanoplates grow perpendicular to the axis of the central of the Te nanorods is proposed. The obtained Sb2Te3–Te heterogeneous nanostructures have a room-temperature electrical conductivity and Seebeck coefficient of 150.2 S cm−1 and 148.1 μV K−1, respectively, and a maximum power factor of 1.02 mW K−2 m−1 can be obtained at 550 K.