Size-controlled synthesis and transport properties of Sb2Te3 nanoplates

Abstract

Antimony telluride (Sb₂Te₃) based compounds are very promising materials for thermoelectric applications at room-temperature. Here, we showed a new method of regulating the size and thickness of single-crystal Sb₂Te₃ nanoplates, and made its surface form amorphous carbon sheaths, namely Sb₂Te₃@C semiconductor heterostructures. Sb₂Te₃ nanoplates with carbon sheaths were synthesized via a one-step hydrothermal process using glucose as a carbonization source. Various washing methods were used to retain or remove amorphous carbon sheaths. Amorphous carbon sheaths were used to control nanoparticles' size, and the thickness of nanoplates being made was reduced to 80 nm, while a relatively large diameter was maintained (>5 μm). Then, after the amorphous carbon sheaths of Sb₂Te₃ nanoplates were removed, high electrical conductivity σ (100 S cm⁻¹) and high Seebeck coefficient S (112 μV K⁻¹) of the remaining Sb₂Te₃ nanoplates were achieved at room temperature. That is to say we used this new method to increase the materials' Seebeck coefficient and maintain its' high conductivity at the same time. This new approach could have significant scientific and technological application value for building blocks of many useful devices.