Apparatus for the measurement of electrical resistivity, Seebeck coefficient, and thermal conductivity of thermoelectric materials between 300 K and 12 K

Alternating 10 nm thermoelectric films of N-type Si/SiGe and P-type Si/SiGe and B4C/B9C have been fabricated on various substrates, electrically joined and thermoelectric properties measured from 40°K up to 700°K. These nanoscale thermoelectric films demonstrate excellent thermoelectric power factors significantly higher than current bulk thermoelectric materials. The implications of the measured thermoelectric Seebeck coefficient data and electrical resistivity data for alternating 10 nm films that are grown to thicknesses of one to 10 microns means efficiencies of 15% at 200°C temperature differences and efficiencies of 30% at 400°C temperature differences. Utilizing Seebeck and resistivity data obtained by Hi-Z and UCSD, along with published bulk thermal conductivity data, which is conservative, unique thermoelectric module and generator concept designs for both power generation and cooling are presented over wide temperature and power ranges.

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Bi2Te3 and Bi2Te3/Nano-SiC Prepared by Mechanical Alloying and Spark Plasma Sintering

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.280-283.397 ◽

2007 ◽

Vol 280-283 ◽

pp. 397-400 ◽

Cited By ~ 4

Author(s):

Jing Liu ◽

Jing Feng Li

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

Mechanical Alloying ◽

Seebeck Coefficient ◽

Spark Plasma Sintering ◽

Thermoelectric Materials ◽

Room Temperature ◽

Mechanically Alloyed ◽

Plasma Sintering ◽

Spark Plasma

Bi2Te3-based alloys are currently best-known, technological thermoelectric materials near room temperature. In this paper, Bi2Te3 and nano-SiC dispersed Bi2Te3 were prepared by mechanical alloying followed by spark plasma sintering (SPS). Raw powders of Bi, Te and SiC were mixed and mechanically alloyed in an argon atmosphere using a planetary ball mill. The SPS temperature was 623K, and the holding time was 5 minutes. The samples were characterized by X-ray Diffraction (XRD) and Scanning electron Microscope (SEM). The thermoelectric properties: i.e. Seebeck coefficient, electrical resistivity and thermal conductivity were measured at temperatures from room temperature to 573K, followed by the evaluation of figure of merit. The results revealed that the SiC dispersion in the Bi2Te3 matrix increased Seebeck coefficient. Although the electrical resistivity was increased somewhat, the thermal conductivity was reduced by the SiC dispersion, indicating that promising thermoelectric materials with enhanced mechanical properties may be obtained in the nano-SiC dispersed Bi2Te3 composites with optimal compositions.

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Investigation of Thermoelectric Materials: Substitution effect of Bi on the Ag1-xPb18MTe20 (M = Sb, Bi) (x = 0, 0.14, 0.3)

MRS Proceedings ◽

10.1557/proc-1044-u03-14 ◽

2007 ◽

Vol 1044 ◽

Author(s):

Mi-kyung Han ◽

Huijun Kong ◽

Ctirad Uher ◽

Mercouri G Kanatzidis

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Thermoelectric Materials ◽

Figure Of Merit ◽

Lattice Thermal Conductivity ◽

Substitution Effect ◽

Dimensionless Figure Of Merit ◽

The Matrix ◽

Mass Fluctuation

AbstractWe performed comparative investigations of the Ag1-xPb18MTe20 (M = Bi, Sb) (x = 0, 0.14, 0.3) system to better understand the roles of Sb and Bi on the thermoelectric properties. In both systems, the electrical conductivity nearly keeps the same values, while the Seebeck coefficient decreases dramatically in going from Sb to Bi. Compared to the lattice thermal conductivity of PbTe, that of AgPb18BiTe20 is substantially reduced. The lattice thermal conductivity of the Bi analog, however, is higher than that of AgPb18SbTe20 and this is attributed largely to the decrease in the degree of mass fluctuation between the nanostructures and the matrix (for the Bi analog). As a result the dimensionless figure of merit ZT of Ag1-xPb18MTe20 (M = Bi) is found to be smaller than that of Ag1-xPb18MTe20 (M = Sb).

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Thermoelectric Materials for Textile Applications

Molecules ◽

10.3390/molecules26113154 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3154

Author(s):

Kony Chatterjee ◽

Tushar K. Ghosh

Keyword(s):

Thermal Conductivity ◽

Carbon Nanotubes ◽

Seebeck Coefficient ◽

Thermoelectric Materials ◽

Figure Of Merit ◽

Inorganic Materials ◽

Peltier Effect ◽

Electronic Textiles ◽

Heating And Cooling ◽

Recent Attention

Since prehistoric times, textiles have served an important role–providing necessary protection and comfort. Recently, the rise of electronic textiles (e-textiles) as part of the larger efforts to develop smart textiles, has paved the way for enhancing textile functionalities including sensing, energy harvesting, and active heating and cooling. Recent attention has focused on the integration of thermoelectric (TE) functionalities into textiles—making fabrics capable of either converting body heating into electricity (Seebeck effect) or conversely using electricity to provide next-to-skin heating/cooling (Peltier effect). Various TE materials have been explored, classified broadly into (i) inorganic, (ii) organic, and (iii) hybrid organic-inorganic. TE figure-of-merit (ZT) is commonly used to correlate Seebeck coefficient, electrical and thermal conductivity. For textiles, it is important to think of appropriate materials not just in terms of ZT, but also whether they are flexible, conformable, and easily processable. Commercial TEs usually compromise rigid, sometimes toxic, inorganic materials such as bismuth and lead. For textiles, organic and hybrid TE materials are more appropriate. Carbon-based TE materials have been especially attractive since graphene and carbon nanotubes have excellent transport properties with easy modifications to create TE materials with high ZT and textile compatibility. This review focuses on flexible TE materials and their integration into textiles.

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Thermoelectric Properties of Semiconducting Intermetallic Compounds: FeGa3and RuGa3

MRS Proceedings ◽

10.1557/proc-793-s8.38 ◽

2003 ◽

Vol 793 ◽

Author(s):

Y. Amagai ◽

A. Yamamoto ◽

C. H. Lee ◽

H. Takazawa ◽

T. Noguchi ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

High Temperature ◽

Seebeck Coefficient ◽

Transport Properties ◽

Figure Of Merit ◽

Room Temperature ◽

Thermoelectric Figure Of Merit ◽

Thermoelectric Figure ◽

High Seebeck Coefficient

ABSTRACTWe report transport properties of polycrystalline TMGa3(TM = Fe and Ru) compounds in the temperature range 313K<T<973K. These compounds exhibit semiconductorlike behavior with relatively high Seebeck coefficient, electrical resistivity, and Hall carrier concentrations at room temperature in the range of 1017- 1018cm−3. Seebeck coefficient measurements reveal that FeGa3isn-type material, while the Seebeck coefficient of RuGa3changes signs rapidly from large positive values to large negative values around 450K. The thermal conductivity of these compounds is estimated to be 3.5Wm−1K−1at room temperature and decreased to 2.5Wm−1K−1for FeGa3and 2.0Wm−1K−1for RuGa3at high temperature. The resulting thermoelectric figure of merit,ZT, at 945K for RuGa3reaches 0.18.

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Thermoelectric Properties of Doped Iron Disilicide

MRS Proceedings ◽

10.1557/proc-626-z8.1 ◽

2000 ◽

Vol 626 ◽

Author(s):

Jun-ichi Tani ◽

Hiroyasu Kido

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Measured Temperature ◽

Iron Disilicide ◽

Measured Temperature Range ◽

Temperature Range

ABSTRACTIn order to investigate the thermoelectric properties of Re-doped β-FeSi2 (Fe1-xRexSi2), Ir-doped β-FeSi2 (Fe1-xIrxSi2), and Pt-doped β-FeSi2 (Fe1-xPtxSi2), the electrical resistivity, the Seebeck coefficient, and the thermal conductivity of these samples have been measured in the temperature range between 300 and 1150 K. Fe1-xRexSi2 is p-type, while Fe1-xIrxSi2 and Fe1-xPt xSi2 are n-type over the measured temperature range. The solubility limits of dopant are estimated to be 0.2at% for Fe1-xRexSi2, 0.5at% for Fe1-xIrxSi2, and 1.9at% for Fe1-xPtxSi2. A maximum ZT value of 0.14 was obtained for Fe1-xPt xSi2 (x=0.03) at the temperature 847 K.

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High-temperature thermoelectric properties of W-substituted CaMnO3

MRS Proceedings ◽

10.1557/opl.2013.85 ◽

2013 ◽

Vol 1490 ◽

pp. 3-8 ◽

Cited By ~ 2

Author(s):

Dimas S. Alfaruq ◽

James Eilertsen ◽

Philipp Thiel ◽

Myriam H Aguirre ◽

Eugenio Otal ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

High Temperature ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Soft Chemistry ◽

Absolute Seebeck Coefficient

AbstractThe thermoelectric properties of W-substituted CaMn1-xWxO3-δ (x = 0.01, 0.03; 0.05) samples, prepared by soft chemistry, were investigated from 300 K to 1000 K and compared to Nb-substituted CaMn0.98Nb0.02O3-δ. All compositions exhibit both an increase in absolute Seebeck coefficient and electrical resistivity with temperature. Moreover, compared to the Nb-substituted sample, the thermal conductivity of the W-substituted samples was strongly reduced. This reduction is attributed to the nearly two times greater mass of tungsten. Consequently, a ZT of 0.19 was found in CaMn0.97W0.03O3-δ at 1000 K, which was larger than ZT exhibited by the 2% Nb-doped sample.

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Thermoelectric Performance of Glass Microsphere Dispersed Bi-Sb Composites at Low Temperature

Materials Science Forum ◽

10.4028/www.scientific.net/msf.743-744.120 ◽

2013 ◽

Vol 743-744 ◽

pp. 120-125

Author(s):

Zhen Chen ◽

Ye Mao Han ◽

Min Zhou ◽

Rong Jin Huang ◽

Yuan Zhou ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Thermoelectric Materials ◽

Sem Analysis ◽

Glass Microsphere ◽

Thermoelectric Performance ◽

X Ray Diffraction ◽

X Ray ◽

Measurement Results

In the present study, the glass microsphere dispersed Bi-Sb thermoelectric materials have been fabricated through mechanical alloying followed by pressureless sintering. The phase composition and the microstructure were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. Electrical conductivity, Seebeck coefficient and thermal conductivity were measured in the temperature range of 77~300 K. The ZT values were calculated according to the measurement results. The results showed that the electrical conductivity, Seebeck coefficient and thermal conductivity decreased by adding glass microsphere into Bi-Sb thermoelectric materials. However, the optimum ZT value of 0.24 was obtained at 260 K, which was increased 10% than that of the Bi-Sb matrix. So it is confirmed that the thermoelectric performance of Bi-Sb-based materials can be improved by adding moderate glass microspheres.

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Thermoelectric Generators of Sequentially Deposited Si/Si+Ge Nano-layered Superlattices

MRS Proceedings ◽

10.1557/proc-1181-dd02-04 ◽

2009 ◽

Vol 1181 ◽

Author(s):

Cydale Smith ◽

Marcus Pugh ◽

Hervie Martin ◽

Rufus Durel Hill ◽

Brittany James ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Thermoelectric Materials ◽

Figure Of Merit ◽

Rutherford Backscattering Spectrometry ◽

Ion Beam ◽

Absolute Temperature ◽

Simulation Software ◽

The Cross

AbstractEffective thermoelectric materials have a low thermal conductivity and a high electrical conductivity. The performance of the thermoelectric materials and devices is shown by a dimensionless figure of merit, ZT = S2sσ/ KTC, σ is the electrical conductivity T/KTC, where S is the Seebeck coefficient, T is the absolute temperature and KTC is the thermal conductivity. In this study we have prepared the thermoelectric generator device of Si/Si+Ge multi-layer superlattice films using the ion beam assisted deposition (IBAD). To determine the stoichiometry of the elements of Si and Ge in the grown multilayer films and the thickness of the grown multi-layer films Rutherford Backscattering Spectrometry (RBS) and RUMP simulation software package were used. The 5 MeV Si ion bombardments were performed to make quantum clusters in the multi-layer superlattice thin films to decrease the cross plane thermal conductivity, increase the cross plane Seebeck coefficient and cross plane electrical conductivity.Keywords: Ion bombardment, thermoelectric properties, multi-nanolayers, Figure of merit.

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Performance and Testing of Novel Quantum Well Thermoelectric Devices

Volume 5: Energy Systems Analysis, Thermodynamics and Sustainability; NanoEngineering for Energy; Engineering to Address Climate Change, Parts A and B ◽

10.1115/imece2010-40842 ◽

2010 ◽

Author(s):

Velimir Jovanovic ◽

Saeid Ghamaty ◽

Norbert B. Elsner ◽

Daniel Krommenhoek ◽

John C. Bass

Keyword(s):

Thermal Conductivity ◽

Electrical Resistivity ◽

Quantum Well ◽

Seebeck Coefficient ◽

Coefficient Of Performance ◽

Test Technique ◽

Low Thermal Conductivity ◽

Barrier Materials ◽

Te Modules ◽

Conversion Efficiencies

New nano-structured thermoelectric (TE) materials have been developed and fabricated that have much higher conversion efficiencies than the state-of-the-art (SOTA) bulk thermoelectrics. In these new quantum well (QW) materials, the carrier and barrier materials (in this case SiGe and Si) are confined in alternating layers less than 10 nm thick, and this confinement has been shown to result in greatly improved TE properties (Seebeck coefficient, electrical resistivity and thermal conductivity) leading to higher TE Figure of Merit, ZT, conversion efficiencies and Coefficient of Performance (COP) for cooling applications than for SOTA thermoelectrics. From the most recent QW test data, ZTs greater than 3 at room temperature have been obtained which constitutes a significant improvement over the SOTA bulk thermoelectrics which have ZTs less than 1. QW materials have the best measured TE power factor (Seebeck coefficient squared divided by electrical resistivity) and, combined with low thermal conductivity substrates, should provide very high efficiency TE modules. The QW TE materials with ZTs greater than 3 lead to conversion efficiencies greater than 20 percent, which allows for much wider commercial applications, particularly in the applications such as the waste-heat recovery from truck engines, refrigeration, and air conditioning, where the SOTA bulk TE modules were shown to be technically feasible but economically unjustified due to low conversion efficiencies. With higher efficiency QW materials, these applications become economically attractive. The above mentioned QW TE ZTs include the effect of the substrate which degrades the overall performance, and a new test technique was developed that eliminates the effect of the substrate and for just the QW films, ZTs greater than 6 have been measured. This illustrated the importance of using a low thermal conductivity substrate in order to achieve good TE performance. In a recent QW test, a conversion efficiency corresponding to 62 percent of the Carnot efficiency was measured and this is believed to be the highest such value ever measured for a TE material. For power generation applications, QW TE generators can be designed for capacities ranging from milliwatts to kilowatts and for cooling applications with capacities ranging from watts to several tons of refrigeration. The paper discusses the effects of the thermal and electrical contact resistances and of substrate thermal conductivity on the TE performance, the status of the prototype QW TE generators and coolers being designed and fabricated, and the latest test results.

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