Graphene inclusion induced ultralow thermal conductivity and improved figure of merit in p-type SnSe

[Formula: see text] ceramic samples have a structure similar to phonon glass electronic crystals, and their thermoelectric properties can be effectively adjusted through repeated grinding and sintering. The results show that multi-sintering can make their grain refined and increase their grain boundary, which will effectively increase density and phonon scattering. Finally, multi-sintering can reduce the resistivity and thermal conductivity, thus obviously improve thermoelectric figure of merit [Formula: see text] of [Formula: see text]. The optimum [Formula: see text] value of 0.26 is achieved at 923 K by the third sintered sample.

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

Физика и техника полупроводников ◽

10.21883/ftp.2019.06.47721.30 ◽

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.

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Thermoelectric Properties of Bi2Te3-ySey Bulk Materials Synthesized by Melting-Grinding Process

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.773.145 ◽

2018 ◽

Vol 773 ◽

pp. 145-151

Author(s):

Min Soo Park ◽

Gook Hyun Ha ◽

Hye Young Koo ◽

Yong Ho Park

Keyword(s):

Thermal Conductivity ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Room Temperature ◽

Thermal Characteristics ◽

Grinding Process ◽

Alloy Scattering ◽

Temperature Range ◽

P Type ◽

Optimal Effect

The Bi–Te thermoelectric system shows an excellent figure of merit (ZT) near room temperature. Research on increasing the ZT value for n‑type Bi–Te is imperative because the thermoelectric properties of this compound are inferior to those of the p-type material. For this purpose, n-type Bi2Te3-ySey powders with various amounts of Se dopant (0.3 ≤ y ≤ 0.6) were synthesized by a vacuum melting-grinding process to improve the physical properties. The ZT value of the sintered bodies was investigated in the temperature range of 298–423 K with regard to the electrical and thermal characteristics. As the Se content increased, the electrical conductivity decreased owing to a reduction in the carrier concentration, which improved the overall value of ZT. The thermal conductivity clearly decreased as the Se content increased in the temperature range of 298–373 K due to increased alloy scattering, as well as a reduction in the lattice thermal conductivity caused by crystal grain boundary scattering. At room temperature, Bi2Te2.7Se0.3 (y = 0.3) exhibited the highest ZT of 0.85. At increased temperatures, the ZT value was highest for Bi2Te2.55Se0.45 (y = 0.45), indicating that the optimal effect of the Se dopants varies depending on the temperature range.

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Synthesis and Thermoelectric Properties of Co4-XFeXSb12-YSnY Skutterudites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.695.65 ◽

2011 ◽

Vol 695 ◽

pp. 65-68 ◽

Cited By ~ 1

Author(s):

Kwan Ho Park ◽

Il Ho Kim

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Figure Of Merit ◽

Phonon Scattering ◽

Charge Compensation ◽

Fe Doping ◽

Sn Doping ◽

Double Doping

Co4-xFexSb12-ySny skutterudites were synthesized by mechanical alloying and hot pressing, and thermoelectric properties were examined. The carrier concentration increased by doping and thereby the electrical conductivity increased compared with intrinsic CoSb3. Every specimen had a positive Seebeck coefficient. Fe doping caused a decrease in the Seebeck coefficient but it could be enhanced by Fe/Sn double doping possibly due to charge compensation. The thermal conductivity was desirably very low and this originated from ionized impurity-phonon scattering. Thermoelectric properties were improved remarkably by Fe/Sn doping, and a maximum figure of merit, ZT = 0.5 was obtained at 723 K in the Co3FeSb11.2Sn0.8 specimen.

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Thermal Conductivity of Zn4−xCdxSb3 Solid Solutions

MRS Proceedings ◽

10.1557/proc-478-103 ◽

1997 ◽

Vol 478 ◽

Cited By ~ 20

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.

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Vacancy Phonon Scattering and Thermoelectric Properties in In2Te3–SnTe Compounds

Materials Science Forum ◽

10.4028/www.scientific.net/msf.650.126 ◽

2010 ◽

Vol 650 ◽

pp. 126-131 ◽

Cited By ~ 5

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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Synthesis and thermoelectric properties of tantalum-doped ZrNiSn half-Heusler alloys

Functional Materials Letters ◽

10.1142/s1793604714500325 ◽

2014 ◽

Vol 07 (03) ◽

pp. 1450032 ◽

Cited By ~ 10

Author(s):

Degang Zhao ◽

Min Zuo ◽

Zhenqing Wang ◽

Xinying Teng ◽

Haoran Geng

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Acoustic Phonon ◽

Figure Of Merit ◽

Room Temperature ◽

Phonon Scattering ◽

Heusler Alloys ◽

Hot Press ◽

Arc Melting ◽

Hot Press Sintering

The Ta -doped ZrNiSn half-Heusler alloys, Zr 1-x Ta x NiSn , were synthesized by arc melting and hot-press sintering. Microstructure of Zr 1-x Ta x NiSn compounds were analyzed and the thermoelectric (TE) properties of Zr 1-x Ta x NiSn compounds were measured from room temperature to 823 K. The electrical conductivity increased with increasing Ta content. The Seebeck coefficient of Zr 1-x Ta x NiSn compounds was sharply decreased with increasing Ta content. The Hall mobility was proportional to T-1.5 above 673 K, indicating that the acoustic phonon scattering was predominant in the temperature range. The thermal conductivity was effectively depressed by introducing Ta substitution. The figure of merit of ZrNiSn compounds was improved due to the decreased thermal conductivity and increased electrical conductivity. The maximum ZT value of 0.60 was achieved for Zr 0.97 Ta 0.03 NiSn sample at 823 K.

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Low lattice thermal conductivity and high figure of merit in p-type doped K3IO

Chinese Physics B ◽

10.1088/1674-1056/abab83 ◽

2020 ◽

Vol 29 (12) ◽

pp. 126501

Author(s):

Weiqiang Wang ◽

Zhenhong Dai ◽

Qi Zhong ◽

Yinchang Zhao ◽

Sheng Meng

Keyword(s):

Thermal Conductivity ◽

Figure Of Merit ◽

Lattice Thermal Conductivity ◽

High Figure ◽

P Type

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Influence of Pd Doping on Electrical and Thermal Properties of n-Type Cu0.008Bi2Te2.7Se0.3 Alloys

Materials ◽

10.3390/ma12244080 ◽

2019 ◽

Vol 12 (24) ◽

pp. 4080 ◽

Cited By ~ 2

Author(s):

Se Yun Kim ◽

Hyun-Sik Kim ◽

Kyu Hyoung Lee ◽

Hyun-jun Cho ◽

Sung-sil Choo ◽

...

Keyword(s):

Thermal Conductivity ◽

Thermal Properties ◽

Carrier Concentration ◽

Figure Of Merit ◽

Lattice Thermal Conductivity ◽

Phonon Scattering ◽

Energy Conversion Efficiency ◽

Thermoelectric Figure ◽

Pd Doping ◽

Effect Of Pd

Doping is known as an effective way to modify both electrical and thermal transport properties of thermoelectric alloys to enhance their energy conversion efficiency. In this project, we report the effect of Pd doping on the electrical and thermal properties of n-type Cu0.008Bi2Te2.7Se0.3 alloys. Pd doping was found to increase the electrical conductivity along with the electron carrier concentration. As a result, the effective mass and power factors also increased upon the Pd doping. While the bipolar thermal conductivity was reduced with the Pd doping due to the increased carrier concentration, the contribution of Pd to point defect phonon scattering on the lattice thermal conductivity was found to be very small. Consequently, Pd doping resulted in an enhanced thermoelectric figure of merit, zT, at a high temperature, due to the enhanced power factor and the reduced bipolar thermal conductivity.

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