Near room temperature power factor of metal sulfides films

2012 ◽  
Author(s):  
J. M. Clamagirand ◽  
J. R. Ares ◽  
I. J. Ferrer ◽  
C. Sánchez
Keyword(s):  
Power Factor ◽  
Room Temperature ◽  
Metal Sulfides

scholarly journals A facile energy-saving route of fabricating thermoelectric Sb 2 Te 3 -Te nanocomposites and nanosized Te

2018 ◽  
Vol 5 (10) ◽  
pp. 180698 ◽  
Author(s):  
En-Yu Liu ◽  
Fei-Hung Lin ◽  
Zong-Ren Yang ◽  
Chia-Jyi Liu
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Power Factor ◽  
Hot Pressing ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Organic Chemicals ◽  
Nanosized Powders ◽  
Dimensionless Figure Of Merit ◽  
Fabrication Procedure

A facile energy-saving route is developed for fabricating Sb 2 Te 3 -Te nanocomposites and nanosized Te powders. The fabrication route not only avoids using organic chemicals, but also keeps the energy consumption to a minimum. The fabrication procedure involves two steps. Energetic precursors of nanosized powders of Sb and Te are produced at room temperature followed by hot pressing at 400°C under 70 MPa for 1 h. The resulting Sb 2 Te 3 -Te nanocomposite exhibits enhanced power factor. The dimensionless figure of merit zT value of the Sb 2 Te 3 -Te nanocomposite is 0.29 at 475 K.

scholarly journals Substitution Versus Full-Heusler Segregation in TiCoSb

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 935 ◽  
Author(s):  
Maryana Asaad ◽  
Jim Buckman ◽  
Jan-Willem Bos
Keyword(s):  
Powder Metallurgy ◽  
Power Factor ◽  
Thermoelectric Materials ◽  
Room Temperature ◽  
The Difference ◽  
P Type ◽  
Full Heusler ◽  
Thermal Conductivities

Half-Heuslers (HHs) are promising thermoelectric materials with great compositional flexibility. Here, we extend work on the p-type doping of TiCoSb using abundant elements. Ti0.7V0.3Co0.85Fe0.15Sb0.7Sn0.3 samples with nominal 17.85 p-type electron count were investigated. Samples prepared using powder metallurgy have negative Seebeck values, S ≤ −120 µV K−1, while arc-melted compositions are compensated semiconductors with S = −45 to +30 µV K−1. The difference in thermoelectric response is caused by variations in the degree of segregation of V(Co0.6Fe0.4)2Sn full-Heusler and Sn phases, which selectively absorb V, Fe, and Sn. The segregated microstructure leads to reduced lattice thermal conductivities, κlat = 4.5−7 W m−1 K−1 near room temperature. The largest power factor, S2/ρ = 0.4 mW m−1 K−2 and ZT = 0.06, is observed for the n-type samples at 800 K. This works extends knowledge regarding suitable p-type dopants for TiCoSb.

Quantum Interference Enhanced Thermoelectricity in Ferrocene Based Molecular Junctions

2019 ◽  
Vol 19 (11) ◽  
pp. 7452-7455
Author(s):  
Ashkan Vakilipour Takaloo ◽  
Hatef Sadeghi
Keyword(s):  
Seebeck Coefficient ◽  
Single Molecule ◽  
Power Factor ◽  
Quantum Interference ◽  
Room Temperature ◽  
Thermoelectric Power Factor ◽  
Molecular Scale ◽  
Single Molecule Junctions ◽  
Path Structure ◽  
Single Path

Recent experimental indications of room-temperature quantum interference in the sub-nanometer single molecules suggest that such effects could be utilized to engineer thermoelectric properties of organic single molecule junctions. In this paper, we show that the thermoelectric power factor is significantly enhanced in double path ferrocene cycles compared to the single path counterpart. Due to quantum interference in the double path structure, the Seebeck coefficient is significantly enhanced while the conductance is less affected compared to single path structure. The power factor of the ferrocene cycles are 1–2 orders of magnitude higher than the best organic material reported today. This opens new avenues for future molecular scale organometallic thermoelectricity.

scholarly journals Impact of the iron substitution on the thermoelectric properties of Co 1− x Fe x S 2 ( x  ≤ 0.30)

2019 ◽  
Vol 377 (2152) ◽  
pp. 20180337 ◽  
Author(s):  
Ulises Acevedo Salas ◽  
Ismail Fourati ◽  
Jean Juraszek ◽  
Fabienne Richomme ◽  
Denis Pelloquin ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Thermoelectric Properties ◽  
Thermoelectric Material ◽  
Power Factor ◽  
Room Temperature ◽  
Low Carbon ◽  
Energy Materials ◽  
Work Samples ◽  
Lattice Part

The strong interplay between magnetism and transport can tune the thermoelectric properties in chalcogenides and oxides. In the case of ferromagnetic CoS 2 pyrite, it was previously shown that the power factor is large at room temperature, reaching 1 mW m −1  K −2 and abruptly increases for temperatures below the Curie transition ( T C ), an increase potentially due to a magnonic effect on the Seebeck ( S ) coefficient. The too large thermal conductivity approximately equal to 10.5 W m −1  K −1 at room temperature prevents this pyrite from being a good thermoelectric material. In this work, samples belonging to the Co 1− x Fe x S 2 pyrite family ( x  = 0, 0.15 and 0.30) have thus been investigated in order to modify the thermal properties by the introduction of disorder on the Co site. We show here that the thermal conductivity can indeed be reduced by such a substitution, but that this substitution predominantly induces a reduction of the electronic part of the thermal conductivity and not of the lattice part. Interestingly, the magnonic contribution to S below T C disappears as x increases, while at high T , S tends to a very similar value (close to −42 µV K −1 ) for all the samples investigated. This article is part of a discussion meeting issue ‘Energy materials for a low carbon future’.

scholarly journals Annealing Effect on the Thermoelectric Properties of Bi2Te3Thin Films Prepared by Thermal Evaporation Method

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Jyun-Min Lin ◽  
Ying-Chung Chen ◽  
Chi-Pi Lin
Keyword(s):  
Thin Films ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Thermal Evaporation ◽  
Thermal Evaporation Method ◽  
Si Substrates ◽  
Seebeck Coefficients

Bismuth telluride-based compounds are known to be the best thermoelectric materials within room temperature region, which exhibit potential applications in cooler or power generation. In this paper, thermal evaporation processes were adopted to fabricate the n-type Bi2Te3thin films on SiO2/Si substrates. The influence of thermal annealing on the microstructures and thermoelectric properties of Bi2Te3thin films was investigated in temperature range 100–250°C. The crystalline structures and morphologies were characterized by X-ray diffraction and field emission scanning electron microscope analyses. The Seebeck coefficients, electrical conductivity, and power factor were measured at room temperature. The experimental results showed that both the Seebeck coefficient and power factor were enhanced as the annealing temperature increased. When the annealing temperature increased to 250°C for 30 min, the Seebeck coefficient and power factor of n-type Bi2Te3-based thin films were found to be about −132.02 μV/K and 6.05 μW/cm·K2, respectively.

scholarly journals Quantized thermoelectric Hall effect induces giant power factor in a topological semimetal

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Fei Han ◽  
Nina Andrejevic ◽  
Thanh Nguyen ◽  
Vladyslav Kozii ◽  
Quynh T. Nguyen ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Hall Effect ◽  
Power Factor ◽  
Room Temperature ◽  
Waste Heat ◽  
Quantum Limit ◽  
Topological Materials ◽  
Weyl Semimetal ◽  
Topological Semimetals ◽  
Electronic Entropy

AbstractThermoelectrics are promising by directly generating electricity from waste heat. However, (sub-)room-temperature thermoelectrics have been a long-standing challenge due to vanishing electronic entropy at low temperatures. Topological materials offer a new avenue for energy harvesting applications. Recent theories predicted that topological semimetals at the quantum limit can lead to a large, non-saturating thermopower and a quantized thermoelectric Hall conductivity approaching a universal value. Here, we experimentally demonstrate the non-saturating thermopower and quantized thermoelectric Hall effect in the topological Weyl semimetal (WSM) tantalum phosphide (TaP). An ultrahigh longitudinal thermopower $$S_{xx} \sim 1.1 \times 10^3 \, \mu \, {\mathrm{V}} \, {\mathrm{K}}^{ - 1}$$ S x x ~ 1.1 × 1 0 3 μ V K − 1 and giant power factor $$\sim 525 \, \mu \, {\mathrm{W}} \, {\mathrm{cm}}^{ - 1} \, {\mathrm{K}}^{ - 2}$$ ~ 525 μ W cm − 1 K − 2 are observed at ~40 K, which is largely attributed to the quantized thermoelectric Hall effect. Our work highlights the unique quantized thermoelectric Hall effect realized in a WSM toward low-temperature energy harvesting applications.

Thermoelectric Power Factor of Polycrystalline La0.75Sr0.25Co1-xMnxO3-δCeramics

2009 ◽  
Vol 1166 ◽  
Author(s):  
Julio E. Rodríguez ◽  
J. A. Niño
Keyword(s):  
Transport Properties ◽  
Thermoelectric Power ◽  
Power Factor ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Manganese Content ◽  
Solid State Reaction Method ◽  
Measured Temperature ◽  
Thermoelectric Power Factor ◽  
Temperature Range

AbstractThermoelectric properties of polycrystalline La0.75Sr0.25Co1-xMnxO3-δ(0<x<0.08) (LSCoO-Mn) compounds have been studied. The samples were grown by solid-state reaction method; their transport properties were studied in the temperature range between 100 and 290K, as a function of temperature and the manganese content. The Seebeck coefficient (S) is positive over the measured temperature range and its magnitude increases with the manganese content up to values close to 160 μV/K. The electrical resistivity (ρ) goes from metallic to semiconducting behavior as the Mn level increases, at room temperature, ρ(T) exhibit values less than 4mΩ-cm. From S(T), ρ(T) and κ(T) data, the thermoelectric power factor and the figure of merit were determined. These performance parameters reach maximum values around 18 μW/K2-cm and 0.2, respectively. The observed behavior in the transport properties become these compounds potential thermoelectric materials, which could be used in thermoelectric applications.

Thermoelectric Properties of Mixed Rhenium Chalcogenides Re6Te15-x Sex (0 ≤ × ≤ 8)

1998 ◽  
Vol 545 ◽  
Author(s):  
S. Kilibarda Dalafave ◽  
J. Ziegler ◽  
H. Mcallister
Keyword(s):  
Thermoelectric Power ◽  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Energy Gap ◽  
Selenium Concentration ◽  
X Ray ◽  
Tetragonal Lattice ◽  
Factor Α ◽  
Volume Decrease

AbstractReported are the temperature dependencies of the thermoelectric power and electrical resistivity of mixed rhenium chalcogenides Re6Te15-x,Sex (0 ≤ x ≤ 8) in the range 90–420 K. Influence of the partial chalcogen exchange on thermoelectric properties of these compounds is discussed. The samples are prepared by sintering elemental powders inside evacuated and sealed quartz ampoules at 1150 K for 170 hours. X-ray analysis reveals an orthorhombic lattice for samples with x < 8 and a tetragonal lattice for the Re6Te7Se8. sample. The lattice parameters and the unit cell volume decrease with increasing selenium concentration.The measurements indicate p-type semiconducting behavior for all samples. The presence of the energy gap is observed at higher temperatures (T ≥ 180–220 K) for all x. Data suggest hopping conduction at lower temperatures. Room temperature resistivities increase non-linearly from 6.9 to 20.4 Ω m with the increasing selenium content. Initially, the thermoelectric power a increases with temperature for all samples, with the fastest increase in Re6Se8 Te7 and the slowest in Re6Te15. The temperature at which a reaches maximum decreases with the increasing Se content. Above this temperature, a decreases uniformly as the temperature increases, the slowest increase being for Re6Se8Te7 and the fastest for Re6Te15. Such α(T) dependence is also discussed. The temperature dependence of the power factor, α2/ρ, is presented. Comparison of ρ, α, and the power factor in Re6SexTe15-x with currently used state-of-the-art materials is given.

Thermoelectric Properties of CoSb3 Nanoparticle Films

2011 ◽  
Vol 347-353 ◽  
pp. 3448-3455
Author(s):  
Ya Jun Yang ◽  
Xian Yun Liu ◽  
Xu Dong Wang ◽  
Mei Ping Jiang ◽  
Xian Feng Chen ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Power Factor ◽  
Room Temperature ◽  
Maximum Power ◽  
Vapor Transport ◽  
Growth Technique ◽  
Highly Efficient ◽  
Nanoparticle Films ◽  
Electrical Conductivities ◽  
Maximum Power Factor

Cobblestone-like CoSb3 nanoparticle films have been achieved via a catalyst-free vapor transport growth technique. The thermoelectric properties of the nanoparticle films were measured from room temperature to around 500 oC. The resultant CoSb3 nanoparticle films show high electrical conductivities due to clean particle surfaces. A maximum power factor reaches 1.848×10−4 W/mK2 at 440 oC. The discussed approach is promising for realizing new types of highly efficient thermoelectric semiconductors.

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