scholarly journals Влияние термической предыстории на свойства эффективных термоэлектрических сплавов Ge-=SUB=-0.86-=/SUB=-Pb-=SUB=-0.1-=/SUB=-Bi-=SUB=-0.04-=/SUB=-Te-=SUP=-*-=/SUP=-

2022 ◽  
Vol 56 (3) ◽  
pp. 261
Author(s):  
А.А. Шабалдин ◽  
А.Ю. Самунин ◽  
П.П. Константинов ◽  
С.В. Новиков ◽  
А.Т. Бурков ◽  
...  
Keyword(s):  
Figure Of Merit ◽  
Structural Modification ◽  
Lattice Thermal Conductivity ◽  
Partial Substitution ◽  
Thermoelectric Efficiency ◽  
Thermoelectric Figure ◽  
Maximum Value ◽  
History Of ◽  
Simultaneous Decrease ◽  
Good Agreement

In this work, we study the properties of GeTe -based alloys, doped with bismuth, with partial substitution of lead for germanium: Ge0.86Pb0.1Bi0.04Te. The aim of the study is to explore the possibility of increasing the thermoelectric efficiency of a compound by combining optimal doping and isovalent substitution to improve the electronic properties with a simultaneous decrease of the lattice thermal conductivity. We studied alloy samples prepared in two different research laboratories using similar, but not completely identical procedures. It is shown that the electronic (thermoelectric power and electrical conductivity) properties of the samples of the two groups are in good agreement with each other. The properties of alloys depend on the thermal history of the samples due to the presence at temperatures of 600–800 K of a phase transition from a low-temperature rhombohedral to a high-temperature cubic structural modification. The thermoelectric figure of merit of alloys reaches a maximum value of 1.5 at a temperature of about 750 K.

Improved thermoelectric efficiency in p-type ZnSb through Zn deficiency

2015 ◽  
Vol 08 (02) ◽  
pp. 1550028 ◽  
Author(s):  
Qilong Guo ◽  
Sijun Luo
Keyword(s):  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Hole Concentration ◽  
Zn Deficiency ◽  
Thermoelectric Efficiency ◽  
Thermoelectric Figure ◽  
Pristine Sample ◽  
Zn Content ◽  
P Type ◽  
Content Regulation

We herein report a feasible approach to improve the thermoelectric performance of p-type ZnSb compound by Zn content regulation. It is found that Zn vacancies formed by Zn deficiency not only efficiently enhance the electrical conductivity due to the improved hole concentration but also markedly lower the lattice thermal conductivity on account of the reinforced point defect scattering of phonons. The ZnSb compound with a nominal 3 mol.% Zn deficiency shows a maximum thermoelectric figure of merit ZT of ~ 0.8 at 700 K which is a ~ 60% improvement over the pristine sample. The strategies of further enhancing the performance of ZnSb -based material have been discussed.

Nanocomposite of Bi2Te3 with Metal Inclusions for Advanced Thermoelectric Applications

2009 ◽  
Vol 1218 ◽  
Author(s):  
Sumithra Santhanam ◽  
Nathan J. Takas ◽  
Dinesh Misra ◽  
Pierre F. P. Poudeu ◽  
Kevin L. Stokes
Keyword(s):  
Thermal Conductivity ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Electrical Power ◽  
Nanometer Scale ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Efficiency ◽  
Thermoelectric Figure ◽  
Thermal And Electrical Properties ◽  
Experimental And Theoretical Studies

AbstractRecent experimental and theoretical studies have shown that the thermal to electrical power conversion efficiency (as measured by the thermoelectric figure of merit) can be enhanced in nanocomposite materials. Primarily, these efforts to improve the thermoelectric efficiency rely on reducing the lattice thermal conductivity through nanostructuring of the materials or the introduction of a second nanometer-scale phase into the composite material. Here, we show that the inclusion of semimetal nanoparticles into bismuth telluride (Bi2Te3) can result in both an increase in the electronic transport properties (so called "power factor") as well as a decrease in lattice thermal conductivity. The effect of different volume fractions of Bi nanoinclusions (3% and 5%) on the thermal and electrical properties of the composite are reported. A marginal increase in the thermoelectric figure of merit is achieved for 3% metal nanoinclusion, whereas a significant improvement in the figure of merit could be achieved for 5% nanoinclusions in the Bi2Te3 thermoelectric matrix.

Effects of Ce filling fraction and Fe content on the thermoelectric properties of Co-rich CeyFexCo4−xSb12

2001 ◽  
Vol 16 (3) ◽  
pp. 837-843 ◽  
Author(s):  
Xinfeng Tang ◽  
Lidong Chen ◽  
Takashi Goto ◽  
Toshio Hirai
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Single Phase ◽  
Lattice Thermal Conductivity ◽  
Hole Concentration ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Filling Fraction ◽  
Fe Content

Single-phase filled skutterudite compounds, CeyFexCo4−xSb12 (x = 0 to 3.0, y = 0 to 0.74), were synthesized by a melting method. The effects of Fe content and Ce filling fraction on the thermoelectric properties of CeyFexCo4−xSb12 were investigated. The lattice thermal conductivity of Ce-saturated CeyFexCo4−xSb12, y being at the maximum corresponding to x, decreased with increasing Fe content (x) and reached its minimum at about x = 1.5. When x was 1.5, lattice thermal conductivity decreased with increasing Ce filling fraction till y = 0.3 and then began to increase after reaching the minimum at y = 0.3. Hole concentration and electrical conductivity of Cey Fe1.5Co2.5Sb12 decreased with increasing Ce filling fraction. The Seebeck coefficient increased with increasing Ce filling fraction. The greatest dimensionless thermoelectric figure of merit T value of 1.1 was obtained at 750 K for the composition of Ce0.28Fe1.52Co2.48Sb12.

scholarly journals Термоэлектрические свойства нанокомпозитного Bi-=SUB=-0.45-=/SUB=-Sb-=SUB=-1.55-=/SUB=-Te-=SUB=-2.985-=/SUB=- с микрочастицами SiO-=SUB=-2-=/SUB=-

2019 ◽  
Vol 53 (6) ◽  
pp. 751
Author(s):  
А.А. Шабалдин ◽  
П.П. Константинов ◽  
Д.А. Курдюков ◽  
Л.Н. Лукьянова ◽  
А.Ю. Самунин ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Solid Solution ◽  
Electrical Conductivity ◽  
Wide Temperature Range ◽  
Figure Of Merit ◽  
Nanostructured Material ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Efficiency ◽  
Thermoelectric Figure ◽  
P Type

AbstractNanocomposite thermoelectrics based on Bi_0.45Sb_1.55Te_2.985 solid solution of p -type conductivity are fabricated by the hot pressing of nanopowders of this solid solution with the addition of SiO_2 microparticles. Investigations of the thermoelectric properties show that the thermoelectric power of the nanocomposites increases in a wide temperature range of 80–420 K, while the thermal conductivity considerably decreases at 80–320 K, which, despite a decrease in the electrical conductivity, leads to an increase in the thermoelectric efficiency in the nanostructured material without the SiO_2 addition by almost 50% (at 300 K). When adding SiO_2, the efficiency decreases. The initial thermoelectric fabricated without nanostructuring, in which the maximal thermoelectric figure of merit ZT = 1 at 390 K, is most efficient at temperatures above 350 K.

scholarly journals Enhanced Thermoelectric Properties of WS2/Single-Walled Carbon Nanohorn Nanocomposites

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 140 ◽  
Author(s):  
Ji Hoon Kim ◽  
Seunggun Yu ◽  
Sang Won Lee ◽  
Seung-Yong Lee ◽  
Keun Soo Kim ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
High Frequency ◽  
Figure Of Merit ◽  
Thermoelectric Efficiency ◽  
Thermoelectric Figure ◽  
Carbon Nanohorns ◽  
Single Walled Carbon ◽  
High Frequency Induction

Recently, two-dimensional tungsten disulfide (WS2) has attracted attention as a next generation thermoelectric material due to a favorable Seebeck coefficient. However, its thermoelectric efficiency still needs to be improved due to the intrinsically low electrical conductivity of WS2. In the present study, thermoelectric properties of WS2 hybridized with highly conductive single-walled carbon nanohorns (SWCNHs) were investigated. The WS2/SWCNH nanocomposites were fabricated by annealing the mixture of WS2 and SWCNHs using a high-frequency induction heated sintering (HFIHS) system. By adding SWCNHs to WS2, the nanocomposites exhibited increased electrical conductivity and a slightly decreased Seebeck coefficient with the content of SWCNHs. Hence, the maximum power factor of 128.41 μW/mK2 was achieved for WS2/SWCNHs with 0.1 wt.% SWCNHs at 780 K, resulting in a significantly improved thermoelectric figure of merit (zT) value of 0.027 compared to that of pristine WS2 with zT 0.017.

Thermoelectric Properties of CoSb3-based Skutterudite Compounds

2010 ◽  
Vol 1267 ◽  
Author(s):  
Adul Harnwunggmoung ◽  
Ken Kurosaki ◽  
Hiroaki Muta ◽  
Shinsuke Yamanaka
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Lattice Thermal Conductivity ◽  
Filling Ratio ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Alloy Scattering ◽  
Skutterudite Compound

AbstractCoSb3 is known as a skutterudite compound that could exhibit high thermoelectric figure of merit. However, the thermal conductivity of CoSb3 is relatively high. In order to enhance the thermoelectric performance of this compound, we tried to reduce the thermal conductivity of CoSb3 by substitution of Rh for Co and by Tl-filling into the voids. The polycrystalline samples of (Co,Rh)Sb3 and Tl-filled CoSb3 were prepared and the thermoelectric properties such as the Seebeck coefficient, electrical resistivity, and thermal conductivity were measured in the temperature range from room temperature to 750 K. The Rh substitution for Co reduced the lattice thermal conductivity, due to the alloy scattering effect. The minimum value of the lattice thermal conductivity was 4 Wm-1K-1 at 750 K obtained for (Co0.7Rh0.3)Sb3. Also the lattice thermal conductivity rapidly decreased with increasing the Tl-filling ratio. T10.25Co4Sb12 exhibited the best ZT values; the maximum ZT was 0.9 obtained at 600 K.

Increasing Efficiencies of Thermoelectric Devices Through Angular Interface Geometries

2009 ◽  
Author(s):  
D. P. Sellan ◽  
C. H. Amon
Keyword(s):  
Thermal Conductivity ◽  
Figure Of Merit ◽  
Equation Model ◽  
Boltzmann Transport ◽  
Thermoelectric Efficiency ◽  
Thermoelectric Figure ◽  
Subsequent Increase ◽  
Acoustic Mismatch ◽  
Out Of Plane ◽  
Plane Direction

The phonon Boltzmann transport equation model is used to evaluate the reduction of out-of-plane thermal conductivity and subsequent increase in thermoelectric figure of merit when an angular interface is patterned between a germanium thin-film and silicon substrate. According to the acoustic mismatch model, the angular structure reduces the out-of-plane thermal conductivity by spatially redistributing phonons traveling in the out-of-plane direction. Simulation results demonstrate a 43% reduction in out-of-plane thermal conductivity when operating in the fully ballistic regime. This decrease in phononic thermal conductivity would result in an increase of intrinsic thermoelectric efficiency by a factor of 1.75.

Thermal Conductivity of Zn4−xCdxSb3 Solid Solutions

1997 ◽  
Vol 478 ◽  
Author(s):  
T. Caillat ◽  
A. Borshchevsky ◽  
J. -P. Fleurial
Keyword(s):  
Thermal Conductivity ◽  
High Performance ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
State Of The Art ◽  
Thermoelectric Figure Of Merit ◽  
Thermoelectric Figure ◽  
Jet Propulsion ◽  
P Type ◽  
Electrical Conductors

Abstractβ-Zn4Sb3 was recently identified at the Jet Propulsion Laboratory as a new high performance p-type thermoelectric material with a maximum dimensionless thermoelectric figure of merit ZT of 1.4 at a temperature of 673K. A usual approach, used for many state-of-the-art thermoelectric materials, to further improve ZT values is to alloy β-Zn4Sb3 with isostructural compounds because of the expected decrease in lattice thermal conductivity. We have grown Zn4−xCdxSb3 crystals with 0.2≤x<1.2 and measured their thermal conductivity from 10 to 500K. The thermal conductivity values of Zn4−xCdxSb3 alloys are significantly lower than those measured for β-Zn4Sb3 and are comparable to its calculated minimum thermal conductivity. A strong atomic disorder is believed to be primarily at the origin of the very low thermal conductivity of these materials which are also fairly good electrical conductors and are therefore excellent candidates for thermoelectric applications.

Vacancy Phonon Scattering and Thermoelectric Properties in In2Te3–SnTe Compounds

2010 ◽  
Vol 650 ◽  
pp. 126-131 ◽  
Author(s):  
Hong Fu ◽  
Peng Zhan Ying ◽  
J.L. Cui ◽  
Y.M. Yan ◽  
X.J. Zhang
Keyword(s):  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Point Defects ◽  
Figure Of Merit ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Chemical Compositions ◽  
Thermoelectric Figure ◽  
Solid Solution Formation ◽  
Solution Formation

Solid solution formation is a common and effective way to reduce the lattice thermal conductivity for thermoelectric materials because of additional phonon scattering by point defects and grain boundaries. In the present work we prepared In2Te3–SnTe compounds using a mild solidification technique and evaluated their thermoelectric properties in the temperature range from 318705 K. Measurements reveal that the transport properties are strongly dependent on the chemical composition  In2Te3 content, and lattice thermal conductivity significantly reduces above a minimum In2Te3 concentration, which can possibly be explained by an introduction of the vacancy on the indium sublattice and periodical vacancy planes. The highest thermoelectric figure of merit ZT of 0.19 can be achieved at 705 K, and a big improvement of In2Te3 based alloys would be expected if a proper optimization to the chemical compositions and structures were made.

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