Solvothermal preparations of nanocrystalline Bi₂Te₃ powders and the study on their characterizations

Abstract

[Abstract] Bi2Te 3 nanoparticles of 15∼25nm were prepared via solvothermal processes in which pyridine, absolute ethanol and distilled water were used as reaction medium respectively. The XRD and TEM have been applied to analyze the samples, and the grain sizes have also been calculated by Scherrer Equation. The results showed that in these experiments, all of the reaction products' purity, crystallization, grain size and tropism increased with dielectric constant and polarity of the solvent. A novel Bi2Te3 nanowires with several tens to a hundred nanometers diameter and up to more than ten microns length have been prepared when distilled water was used as reaction medium.

Direct Growth of Compound Semiconductor Nanowires by On-Film Formation of Nanowires: Bismuth Telluride

“…There are two reasons for this interest: first, nanowires have unusual and unique physical properties, such as quantum-mechanical confinement effects (QCE) and a high surface-to-volume ratio making them relevant for the development of new devices and sensors. , In particular, it is believed that QCE plays a crucial role in improving the thermoelectric properties of materials. , Theoretical investigations have suggested that low-dimensional materials, such as Bi 2 Te 3 nanowires may exhibit ZT values much larger than 1.0 as a consequence of both the enhanced thermoelectric power ( S ) and electrical conductivity (σ) and depressed thermal conductivity (κ), which is in contrast with the corresponding properties of the bulk material . These predictions have stimulated interest in the development of numerous growth methods − to synthesize Bi 2 Te 3 nanowires over the past decade. Second, no simple method has been found to date for fabricating nanowires over large areas with compositions such as Bi 2 Te 3 .…”

“…Second, no simple method has been found to date for fabricating nanowires over large areas with compositions such as Bi 2 Te 3 . Generally, the synthesis of bismuth telluride-based nanowires can be divided into two categories, electrodeposition into nanoscale inorganic templates − and surfactant-mediated solvothermal techniques. − Although electrodeposition into nanoporous templates is an attractive method for producing aligned nanorod arrays and making good electrical contacts, this technique is suboptimal for producing of single crystals providing high charge-carrier mobilities . On the other hand, solvothermal techniques typically involve reduction of BiPh 3 and TeCl 4 , or BiCl 3 and tellurium powder in organic solvents in the presence of surfactants. , Such techniques for growing Bi 2 Te 3 nanowires, however, have required the use of templates, catalysts, or other starting materials.…”

“…4,5 Theoretical investigations 6 have suggested that low-dimensional materials, such as Bi 2 Te 3 nanowires may exhibit ZT values much larger than 1.0 as a consequence of both the enhanced thermoelectric power (S) and electrical conductivity (σ) and depressed thermal conductivity (κ), which is in contrast with the corresponding properties of the bulk material. 7 These predictions have stimulated interest in the development of numerous growth methods [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] to synthesize Bi 2 Te 3 nanowires over the past decade. Second, no simple method has been found to date for fabricating nanowires over large areas with compositions such as Bi 2 Te 3 .…”

A study of the synthesis of bismuth tellurium selenide nanocompounds and procedures for improving their thermoelectric performance

“…Relatively high ZT values are often exhibited in these QDs or SL structures, but the commercial use of these substances is difficult because of complicated production processes and high costs. Therefore, some groups have focused on using nanobulk structures, such as nanoparticles [22][23][24], nanotubes [25][26][27], and nanowires [28][29][30]. Not only do these nanostructures still exhibit the phonon scattering effect, which reduces Ä, but they can also be prepared by cheaper methods.…”

Fabrication of antimony telluride nanoparticles using a brief chemical synthetic process under atmospheric conditions

“…Relatively high ZT values were often exhibited in these QDs or SL structures, but it has generally been known that commercial use of these substances is difficult due to complicated production processes and high costs. Therefore, some groups are focusing on the approach using nanobulk structures such as nanoparticles [22][23][24], nanotubes [25][26][27], and nanowires [28][29][30]. Not only do these nanostructures still have the phonon scattering effect, which reduces Ä, but they also can be prepared using cheaper processes.…”