High Yield Bi₂Te₃ Single Crystal Nanosheets with Uniform Morphology via a Solvothermal Synthesis

Abstract

Hexagonal nanosheet of Bi 2 Te 3 single crystals with uniform morphology were facilely synthesized through a high yield solvothermal route at low temperature (180 °C). Xray diffraction, scanning electron microscope, transmission electron microscope, selected area electron diffraction, and high-resolution transmission electron microscope were employed to characterize the products. In this solvothermal process, ethylene glycol (EG) was used as both reducing agent and solvent to simplify the process. The reaction temperature and alkaline environment play important roles in the formation of Bi 2 Te 3 single crystals, and the morphology of the products can be influenced by the added surfactants. Nanosheets with uniform morphology were obtained when polyvinyl pyrrolidone (PVP) was used as surfactant. Transport properties of hot pressed bulk samples formed by the as-prepared nanosheets were investigated. Thermal conductivity of the hot pressed nanosheets was greatly reduced by up to 60%, compared to the melt sample, with an enhancement of Seebeck coefficient and a decrease of electrical conductivity.

Thermal annealing effect on structural and thermoelectric properties of hexagonal Bi2Te3 nanoplate thin films by drop-casting technique

“…Bi 2 Te 3 nanoplates usually contain a single-crystalline phase, with the typical diameter on the order of submicrons and thickness of approximately 30 nm. [15][16][17] The electrical and thermal transports along the top-bottom crystallite plane are quite different from those along the c-axis direction, which is perpendicular to these top-bottom planes. In addition, it has been recently reported that ultrathin nanoplates of Bi 2 Te 3 and related alloys exhibit the characteristics of topological insulators.…”

Enhancing thermoelectric performance of Bi2Te3-based nanostructures through rational structure design

“…12 Especially, rhombohedral structured Bi 2 Te 3 nanoplates, as twodimensional nanostructures, [13][14][15] exhibit strengthened phonon scattering due to the dense grain boundaries after sintered into pellets. 16 To further strengthen the phonon scattering, we can assemble the randomly orientated nanoplates in the form of well-aligned hierarchical nanostructures.…”

Green synthesis and formation mechanism of nanostructured Bi2Te3 using ascorbic acid in aqueous solution

“…2(e). Syntheses of disk-like Bi 2 Te 3 NPs with diameters ranging from approximately 10 nm-2.0 lm by various synthesis methods were widely reported [14,18,[21][22][23][24][25][26][27][28]. A rhombohedral Bi 2 Te 3 crystal has a layered anisotropic lattice structure with the Te and Bi atom layers arranged in the order of -Te (1) -Bi-Te (2) -Bi-Te (1) -along the c-axis direction [10].…”