scholarly journals Enhancement in thermoelectric properties due to Ag nanoparticles incorporated in Bi2Te3 matrix

2019 ◽  
Vol 10 ◽  
pp. 634-643 ◽  
Author(s):  
Srashti Gupta ◽  
Dinesh Chandra Agarwal ◽  
Bathula Sivaiah ◽  
Sankarakumar Amrithpandian ◽  
Kandasami Asokan ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
Transmission Electron ◽  
High Power Factor ◽  
Different Temperatures ◽  
High Figure ◽  
Filtering Effect ◽  
P Type ◽  
20 Nm

The present study aims to see the enhancement in thermoelectric properties of bismuth telluride (Bi2Te3) annealed at different temperatures (573 and 773 K) through silver (Ag) nano-inclusions (0, 2, 5, 10, 15 and 20 wt %). Transmission electron microscopy (TEM) images of Ag incorporated in Bi2Te3 annealed at 573 K shows tubular, pentagonal, trigonal, circular and hexagonal nanoparticles with sizes of 6–25 nm (for 5 wt % Ag ) and 7–30 nm (for 20 wt % Ag). Ag incorporated in Bi2Te3 annealed at 773 K shows mainly hexagonally shaped structures with particle sizes of 2–20 nm and 40–80 nm (for 5 wt % Ag) and 10–60 nm (for 20 wt % Ag). Interestingly, the samples annealed at 573 K show the highest Seebeck coefficient (S, also called thermopower) at room temperature (p-type behavior) for 5% Ag which is increased ca. five-fold in comparison to Ag-free Bi2Te3, whereas for samples with the same content (5% Ag) annealed at 773 K the increment in thermopower is only about three-fold with a 6.9-fold enhancement of the power factor (S 2σ). The effect of size and shape of the nanoparticles on thermoelectric properties can be understood on the basis of a carrier-filtering effect that results in an increase in thermopower along with a control over the reduction in electrical conductivity to maintain a high power factor yielding a high figure of merit.

scholarly journals Development of Spark Plasma Syntering (SPS) technology for preparation of nanocrystalline p-type thermoelctrics based on (BiSb)2Te3

2020 ◽  
Vol 21 (4) ◽  
pp. 628-634
Author(s):  
O. Kostyuk ◽  
B. Dzundza ◽  
M. Maksymuk ◽  
V. Bublik ◽  
L. Chernyak ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Antimony Telluride ◽  
Bismuth Antimony Telluride ◽  
Thermoelectric Figure ◽  
Temperature Range ◽  
Plasma Sintering ◽  
Different Temperatures ◽  
Spark Plasma ◽  
P Type

Bismuth antimony telluride is the most commonly used commercial thermoelectric material for power generation and refrigeration over the temperature range of 200–400 K. Improving the performance of these materials is a complected balance of optimizing thermoelectric properties. Decreasing the grain size of Bi0.5Sb1.5Te3 significantly reduces the thermal conductivity due to the scattering phonons on the grain boundaries. In this work, it is shown the advances of spark plasma sintering (SPS) for the preparation of nanocrystalline p-type thermoelectrics based on Bi0.5Sb1.5Te3 at different temperatures (240, 350, 400oC). The complex study of structural and thermoelectric properties of Bi0.5Sb1.5Te3 were presented. The high dimensionless thermoelectric figure of merit ZT ~ 1 or some more over 300–400 K temperature range for nanocrystalline p-type Bi0.5Sb1.5Te3 was obtained.

Doping Studies of n-Type CsBi4Te6 Thermoelectric Materials

2000 ◽  
Vol 626 ◽  
Author(s):  
Melissa A. Lane ◽  
John R. Ireland ◽  
Paul W. Brazis ◽  
Theodora Kyratsi ◽  
Duck-Young Chung ◽  
...  
Keyword(s):  
Power Factor ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Doping Concentration ◽  
High Figure ◽  
P Type ◽  
Optimum Doping Concentration

ABSTRACTWe have previously reported the successful p-type doping of CsBi4Te6 which had a high figure of merit at temperatures below 300 K. In this study, several dopants were explored to make n-type CsBi4Te6. A program of measurements was performed to identify the optimum doping concentration for several series of dopants. The highest power factors occurred around 125 K for the 0.5% Sn doped CsBi4Te6 sample which had a power factor of 21.9 μW/cm•K2 and 1.0% Te doped CsBi4Te6 which had a power factor of 21.7 μW/cm•K2.

scholarly journals Current transport and thermoelectric properties of very high power factor Fe3O4/SiO2/p-type Si(001) devices

2014 ◽  
Vol 115 (3) ◽  
pp. 033709 ◽  
Author(s):  
M. Zervos ◽  
Z. Viskadourakis ◽  
G. Athanasopoulos ◽  
R. Flores ◽  
O. Conde ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Power Factor ◽  
High Power ◽  
Current Transport ◽  
High Power Factor ◽  
P Type ◽  
Very High

High thermoelectric performance of superionic argyrodite compound Ag8SnSe6

2016 ◽  
Vol 4 (24) ◽  
pp. 5806-5813 ◽  
Author(s):  
Lin Li ◽  
Yuan Liu ◽  
Jiyan Dai ◽  
Aijun Hong ◽  
Min Zeng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Material ◽  
Power Factor ◽  
High Power ◽  
Figure Of Merit ◽  
Environmentally Friendly ◽  
Thermoelectric Performance ◽  
Low Thermal Conductivity ◽  
High Power Factor ◽  
High Figure

A good thermoelectric material usually has a high power factor and low thermal conductivity for high figure of merit (ZT), and is also environmentally friendly and economical.

Crystal structure and thermoelectric properties of ReSi1.75 silicide

2002 ◽  
Vol 753 ◽  
Author(s):  
J-J Gu ◽  
K. Kuwabara ◽  
K. Tanaka ◽  
H. Inui ◽  
M. Yamaguchi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Thermoelectric Properties ◽  
First Principles ◽  
Figure Of Merit ◽  
First Principles Calculation ◽  
Dimensionless Figure Of Merit ◽  
Transmission Electron ◽  
P Type ◽  
Very High

ABSTRACTThe crystal structure of the defect disilicide formed with Re (ReSi1.75) has been refined by transmission electron microscopy combined with first-principles calculation. The crystal structure is monoclinic with the space group Cm (mc44) due to an ordered arrangement of vacancies on Si sites in the underlying (parent) C11b lattice. The thermoelectric properties of ReSi1.75 are highly anisotropic. Its electrical conduction is of n-type when measure along [001] while it is of p-type when measured along [100]. Although the value of Seebeck coefficient along [100] is moderately high (150–200 μV/K), it is very high along [001] (250–300 μV/K). As a result, a very high value of dimensionless figure of merit (ZT) of 0.7 is achieved at 1073 K when measured along [001].

Fabrication of Mg2Si from a Reused-silicon Source and its Thermoelectric Characteristics

2007 ◽  
Vol 1044 ◽  
Author(s):  
Masayasu Akasaka ◽  
Tsutomu Iida ◽  
Youhiko Mito ◽  
Takeru Omori ◽  
Yohei Oguni ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Power Factor ◽  
Figure Of Merit ◽  
Silicon Source ◽  
Figures Of Merit ◽  
Dimensionless Figure Of Merit ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type ◽  
Type Sample

AbstractPolycrystalline Mg2Si was fabricated from a reused-Silicon source, based on Si sludge, using Spark Plasma Sintering technique. The n-type and p-type dopants, bismuth (Bi) and silver (Ag), respectively, were incorporated into the Mg2Si. The thermoelectric properties were estimated from 300 to 873K. The power factors of undoped and Bi-doped samples from the reused-Si source were comparable to those from a solar grade Si source (99.99999%). The power factor was estimated to be 2.5 × 10-5 W/cmK2 for the Bi-doped sample from the reused-Si source. However, the power factor of the Ag-doped, p-type sample from the reused-Si source was lower than that from solar grade Si source. The dimensionless figures of merit of samples from the resused-Si source were slightly lower than those from a solar grade Si source. The dimensionless figure of merit was estimated to be 0.53 at 812 K for Bi-doped sample from the reused-Si source.

scholarly journals Thermoelectric properties of Nb-doped Sr1−x (La0.5Na0.5) x TiO3 perovskites

2021 ◽  
Author(s):  
Makoto Tachibana ◽  
Ahmad Rifqi Muchtar ◽  
Takao Mori
Keyword(s):  
Thermal Conductivity ◽  
Solid Solution ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
High Power ◽  
Figure Of Merit ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
High Power Factor ◽  
Nb Doping

Abstract We report the thermal conductivity (κ) of perovskite Sr1−x(La0.5Na0.5)xTiO3 (0 ≤ x ≤ 1) and the thermoelectric properties of Nb-doped samples for x = 0.1 and 0.2. The κ of the solid solution shows a distinct minimum near the cubic-tetragonal phase boundary at x = 0.2, where the value becomes close to the minimum theoretical κ. Nb doping to x = 0.2 retains the high power factor found in Nb-doped SrTiO3, but also raises the κ to result in a thermoelectric figure of merit of 0.24 at 773 K.

Improvements of Thermoelectric Performances in AgSbTe2 System With in-situ Ag2Te Nano-Precipitations

2010 ◽  
Vol 1267 ◽  
Author(s):  
Shengnan Zhang ◽  
Shenghui Yang ◽  
Guangyu Jiang ◽  
Junjie Shen ◽  
Tiejun Zhu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
State Of The Art ◽  
Critical Component ◽  
Energy Filtering ◽  
Transmission Electron ◽  
Filtering Effect ◽  
The Relationship

AbstractAgSbTe2 is the critical component in both LAST-m and TAGS-x system, which are two state-of-the-art mid-temperature thermoelectric bulk nanocomposites. By adjusting the Ag2Te/Sb2Te3 ratio, Sb2Te3 and Ag2Te precipitated samples were obtained with x = 0.68 to 0.74 and x = 0.84 to 0.90 (x as in (Ag2Te)x/2(Sb2Te3)1-x/2), respectively. The single phased AgSbTe2 was obtained with the x value of 0.78 and 0.81, which is consistent of the previous results on the phase diagram of (Ag2Te)x(Sb2Te3)1-x system. Comparing the effect of the two different precipitates, Ag2Te are much effective for the improvements of thermoelectric properties in AgSbTe2 nanocomposites. Utilizing the high-resolution transmission electron microscopy, Ag2Te was observed as nanodots and nano-lamellae embedded in the AgSbTe2 matrix, which can be related to the energy filtering effect for the increase of Seebeck coefficient. The relationship among the composition, microstructure and thermoelectric properties was systematically studied. It can be noticed that the thermoelectric properties of AgSbTe2 system are very sensitive to the composition, especially at low temperature. The maximum figure of merit ZT value of 1.53 was obtained at 500 K for Ag0.84Sb1.16Te2.16 with 40% increase comparing with the single phased sample.

scholarly journals Mechanosynthesis and Thermoelectric Properties of Fe, Zn, and Cd-Doped P-Type Tetrahedrite: Cu12-xMxSb4S13

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3448
Author(s):  
Francisco Arturo López Cota ◽  
José Alonso Díaz-Guillén ◽  
Oscar Juan Dura ◽  
Marco Antonio López de la Torre ◽  
Joelis Rodríguez-Hernández ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Powder Processing ◽  
High Energy ◽  
Secondary Phases ◽  
Ambient Conditions ◽  
Cadmium Sulfate ◽  
Electrical Conductivities ◽  
Compositional Changes ◽  
P Type

This contribution deals with the mechanochemical synthesis, characterization, and thermoelectric properties of tetrahedrite-based materials, Cu12-xMxSb4S13 (M = Fe2+, Zn2+, Cd2+; x = 0, 1.5, 2). High-energy mechanical milling allows obtaining pristine and substituted tetrahedrites, after short milling under ambient conditions, of stoichiometric mixtures of the corresponding commercially available binary sulfides, i.e., Cu2S, CuS, Sb2S3, and MS (M = Fe2+, Zn2+, Cd2+). All the target materials but those containing Cd were obtained as single-phase products; some admixture of a hydrated cadmium sulfate was also identified by XRD as a by-product when synthesizing Cu10Cd2Sb4S13. The as-obtained products were thermally stable when firing in argon up to a temperature of 350–400 °C. Overall, the substitution of Cu(II) by Fe(II), Zn(II), or Cd(II) reduces tetrahedrites’ thermal and electrical conductivities but increases the Seebeck coefficient. Unfortunately, the values of the thermoelectric figure of merit obtained in this study are in general lower than those found in the literature for similar samples obtained by other powder processing methods; slight compositional changes, undetected secondary phases, and/or deficient sintering might account for some of these discrepancies.

Fabrication of Bi-Te Based Thermoelectric Semiconductors by Using Hybrid Powders

2005 ◽  
Vol 297-300 ◽  
pp. 875-880
Author(s):  
Cheol Ho Lim ◽  
Ki Tae Kim ◽  
Yong Hwan Kim ◽  
Dong Choul Cho ◽  
Young Sup Lee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Single Crystals ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Figure Of Merit ◽  
Bending Strength ◽  
Mixing Ratio ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
P Type

P-type Bi0.5Sb1.5Te3 compounds doped with 3wt% Te were fabricated by spark plasma sintering and their mechanical and thermoelectric properties were investigated. The sintered compounds with the bending strength of more than 50MPa and the figure-of-merit 2.9×10-3/K were obtained by controlling the mixing ratio of large powders (PL) and small powders (PS). Compared with the conventionally prepared single crystal thermoelectric materials, the bending strength was increased up to more than three times and the figure-of-merit Z was similar those of single crystals. It is expected that the mechanical properties could be improved by using hybrid powders without degradation of thermoelectric properties.

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