The lack of desirable diffusion barrier layers currently prohibits the long-term stable service of bismuth telluride thermoelectric devices in low-grade waste heat recovery. Here we propose a new ...
Bismuth telluride and its alloys are widely used as materials for thermoelectric refrigeration. They are also the best materials for use in thermoelectric generators when the temperature of the heat source is moderate. The dimensionless figure of merit, ZT, usually rises with temperature, as long as there is only one type of charge carrier. Eventually, …
Bismuth telluride, bismuth selenide, and all intermediate alloys Bi2Te3−xSe x have the tetradymite crystal structure in the symmetry group R3m (Figure 1) [24, 25]. The material is comprised of repeating quintuple layers of Xð1Þ –Bi–Xð2Þ –Bi–Xð1Þ where the number in parentheses designates two inequivalent chalcogen (X) sites. Bismuth
Since lead is a group 14 element close to bismuth, which is a group 15 element, lead is a typical element that is added as a single dopant into p-type bismuth telluride [30,31]. Therefore, we added additional lead, which works as an effective acceptor, into Bi 0.3 Sb 1.7 Te 3.0+0.01 to vary the electrical properties in a wider range.
Bismuth telluride (BiTe) exhibits chemical stability and excellent low-temperature TE performance 20,21 and is currently the most reliable choice for low-grade waste heat …
Nanostructured thermoelectric materials ideally reduce lattice thermal conductivity without harming the electrical properties. Thus, to truly improve the thermoelectric performance, the quality factor, which is proportional to the weighted mobility divided by the lattice thermal conductivity of the material,
We demonstrate p- and n-type bismuth telluride (BiTe) alloys with high (zT) avg leading to efficient module performance for waste heat recovery application in the temperature …
Since thermoelectric technology will be greatly enhanced by improving Bi 2 Te 3 or finding a superior material, this review aims to identify …
Alloying bismuth telluride with antimony telluride and bismuth selenide for p- and n-type materials, respectively, improves the thermoelectric quality factor for use in room temperature modules.
Bismuth telluride (Bi 2 Te 3) is the most mature thermoelectric material that has been well commercialized for electronic cooling and has gradually been used for power generation using low- and medium-temperature waste heat.In the last decade, extensive efforts have been devoted to its performance enhancement, which attracts interests from both …
Bismuth telluride is the most efficient and most widely used thermoelectric material for low-temperature applications (up to 200 °C).
Solid solutions (SSs) based on bismuth and antimony chalcogenides are effective low-temperature thermoelectrics with optimal properties for the temperature range of 100–500 K, depending on the composition and concentration of charge carriers [1, 2], besides, they are promising topological insulators [3, 4].In these materials, topological surface states occur as a …
Bismuth telluride and its alloys are widely used as materials for thermoelectric refrigeration. They are also the best materials for use in thermoelectric generators when the …
Assuming a similar situation for bismuth telluride we estimate a highly approximate value of phonon thermal conductivity ≈0.16 W m −1 K −1. From the calculated values of α, σ, and k e from Eqs.
The quasiparticle band structure of bismuth telluride Bi2Te3, an important thermoelectric material that exhibits topologically insulating surface states, is calculated from first principles in the GW approximation. The quasiparticle energies are evaluated in fine detail in the first Brillouin zone using a Wannier-function interpo- lation method, allowing the accurate determination of the ...
Request PDF | Atomic composition changes in bismuth telluride thin films by thermal annealing and estimation of their thermoelectric properties using experimental analyses and first-principles ...
Bismuth telluride (Bi 2 Te 3) based thermoelectric materials exhibit their best performance near room temperature making them an ideal candidate to power wearable electronics and sensors using body heat. In this report, Bi 2 Te 3 thin films are deposited on a flexible polyimide substrate using low-cost and scalable manufacturing methods.
The power generated by a thermoelectric unicouple module made of Bi2Te3 alloy was evaluated by use of a newly developed instrument. An electrical load was connected to the module, and the terminal voltage and output power of the module were obtained by altering electric current. Water flow was used to cool the cold side of the module and for heat flow …
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, …
Estimates of 1-1 eV and 1-4 e V have been obtained for the spin orbit splitting of the respective valence and conduction bands involved in those transitions in bismuth telluride. 1. INTRODUCTION THE most effective approach to the evaluation of the electronic band structure of a semiconductor from the experimental side is the determination of ...
In this work BixTey thin films were deposited on polyimide substrate by a high-pressure RF magnetron sputtering technique. The deposited condition was maintained using a high pressure of 1.3 × 10−2 mbar. The as-deposited films show Bi2Te3 structure with Te excess phase (Te-rich Bi2Te3). After that, as-deposited films were annealed in the vacuum chamber …
Bismuth telluride-based thermoelectric devices are the only thermoelectric devices that are currently used in large-scale commercial applications. In actual production, nitric acid roughening solution corrodes them and generates a black substance on the surface that is difficult to remove. The exact composition of the black film is not known, which makes its removal …
The band gap and electronic transport in p- and n-type bismuth telluride alloys show important differences in compositional trends due to the details of their complex band …
The ZT of the composite could be raised significantly if pristine bismuth telluride had a higher value of ZT. 4. Conclusions. Multiwall carbon nanotubes in different (0.5, 1.0, 1.5, and 2) vol% were uniformly dispersed in nanostructured bismuth telluride. The pristine Bi 2 Te 3 and composite powders were sintered in a spark plasma-sintering ...
Yonezawa, S., Tabuchi, T. & Takashiri, M. Atomic composition changes in bismuth telluride thin films by thermal annealing and estimation of their thermoelectric properties using experimental ...
Bismuth telluride is the most efficient and most widely used thermoelectric material for low-temperature applications (up to 200 °C). Currently, there are a range of fabrication techniques being used for thin film fabrication, such as sputtering, chemical vapor deposition (CVD), pulsed laser deposition (PLD), molecular beam epitaxy (MBE), evaporation, …
Bismuth telluride Bi 2 Te 3 consists of heavy atoms; that is one of the reasons for its high thermoelectric efficiency. Crystal structure of Bi 2 Te 3 (Fig. 1.1, left) is characterized by rhombohedral actual primitive cell (Fig. 1.1, top right).Lattice constant c of the rhombohedral cell (between bottom and top points) equals to approximately 5.08 nm. This is maximal size of …
High-purity bismuth telluride (Bi2Te3) nanostructures have been synthesized by a chemical reduction method with two processes: (1) co-precipitation by NaBH4 and (2) annealing under hydrazine vapor and nitrogen gas atmosphere at T = 300°C. Based on the use of nitric acid (HNO3) in the preparation of precursor solutions from primary materials, two syntheses were …
PGEs occur (essentially as Pt–Fe alloy, Pt–Pd sulfide, and Pt–Pd bismuth telluride) at the contact between the base-metal sulfides and silicates or oxides, and included mostly within pentlandite and pyrrhotite, and less significant in chalcopyrite. The multidisciplinary analysis using three-dimensional (3-D) X-ray tomography, and in situ ...
Alloying bismuth telluride with antimony telluride and bismuth selenide for p- A nd n-type materials, respectively, improves the thermoelectric quality factor for use in room temperature modules. As the electronic and thermal transports can vary substantially, the alloy composition is a key engineering parameter.
However, the overall flexibility of 3D Bi 2 Te 3-based TEDs is still limited due to the rigidity of the thermoelectric cells.When the device experiences thousands of repeated bending cycles, the interface between the electrode and the thermoelectric leg becomes unstable, leading to high internal resistance or even cracks [190].To further improve the flexibility of TEDs, 2D …
Bismuth telluride and its alloys are widely used as materials for thermoelectric refrigeration. They are also the best materials for use in thermoelectric generators when the temperature of the heat source is moderate. ... In actual fact, the Seebeck coefficient of this compound can exceed ±250 μV/K but it is not surprising that the estimate ...
Fig. 2 shows the XRD patterns of the bismuth telluride thin films at different annealing temperatures. In Fig. 2 (a), when the annealing temperature was less than 300 °C, the XRD peaks derived from 00l of the Bi 2 Te 3 crystalline phase that increased with the annealing temperature, indicating that the crystal orientation along the c-axis increased and the …
