Size-controlled synthesis and transport properties of Sb2Te3 nanoplates

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 onestep 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 mm). Then, after the amorphous carbon sheaths of Sb2Te3 nanoplates were removed, high electrical conductivity sigma (100 S cm(-1)) and high Seebeck coefficient S (112 mV 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.