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.