Bismuth telluride nanostructures: preparation,thermoelectric properties and topological insulating effect

Bismuth telluride is known to wield unique properties for a wide range of device applications. However, as devices migrate to the nanometer scale, significant amount of studies are being conducted to keep up with the rapidly growing nanotechnological field. Bi₂Te₃ possesses distinctive properties at the nanometer level from its bulk material. Therefore, varying synthesis and characterization techniques are being employed for the realization of various Bi₂Te₃ nanostructures in the past years. A considerable number of these works have aimed at improving the thermoelectric (TE) figure-of-merit (ZT) of the Bi₂Te₃ nanostructures and drawing from their topological insulating properties. This paper reviews the various Bi₂Te₃ and Bi₂Te₃-based nanostructures realized via theoretical and experimental procedures. The study probes the preparation techniques, TE properties and the topological insulating effects of 0D, 1D, 2D and Bi₂Te₃ nanocomposites. With several applications as a topological insulator (TI), the topological insulating effect of the Bi₂Te₃ is reviewed in detail with the time reversal symmetry (TRS) and surface state spins which characterize TIs. Schematics and preparation methods for the various nanostructural dimensions are accordingly categorized.