Stacking Fault-Induced Minimized Lattice Thermal Conductivity in the High-Performance GeTe-Based Thermoelectric Materials upon Bi2Te3 Alloying

This work shows that the carrier mean free path of TAGS-85 thermoelectric materials is comparable to the lattice parameter, and that refining the grain size will not affect the mobility while benefiting the thermal conductivity reduction. A state-of-the-art ZT of ~ 1.6 is obtained for the fine-grained samples.

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The origin of the lattice thermal conductivity enhancement at the ferroelectric phase transition in GeTe

npj Computational Materials ◽

10.1038/s41524-021-00523-7 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Đorđe Dangić ◽

Olle Hellman ◽

Stephen Fahy ◽

Ivana Savić

Keyword(s):

Phase Transition ◽

Thermal Conductivity ◽

Phase Transitions ◽

Thermoelectric Materials ◽

Ferroelectric Phase Transition ◽

Lattice Thermal Conductivity ◽

Ferroelectric Phase ◽

Structural Phase ◽

High Symmetry ◽

Structural Phase Transitions

AbstractThe proximity to structural phase transitions in IV-VI thermoelectric materials is one of the main reasons for their large phonon anharmonicity and intrinsically low lattice thermal conductivity κ. However, the κ of GeTe increases at the ferroelectric phase transition near 700 K. Using first-principles calculations with the temperature dependent effective potential method, we show that this rise in κ is the consequence of negative thermal expansion in the rhombohedral phase and increase in the phonon lifetimes in the high-symmetry phase. Strong anharmonicity near the phase transition induces non-Lorentzian shapes of the phonon power spectra. To account for these effects, we implement a method of calculating κ based on the Green-Kubo approach and find that the Boltzmann transport equation underestimates κ near the phase transition. Our findings elucidate the influence of structural phase transitions on κ and provide guidance for design of better thermoelectric materials.

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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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Intrinsically Low Lattice Thermal Conductivity in Natural Superlattice (Bi2)m(Bi2Te3)n Thermoelectric Materials

Chemistry of Materials ◽

10.1021/acs.chemmater.0c03691 ◽

2021 ◽

Vol 33 (4) ◽

pp. 1140-1148

Author(s):

Hao Zhu ◽

Chenchen Zhao ◽

Pengfei Nan ◽

Xiao-ming Jiang ◽

Jiyin Zhao ◽

...

Keyword(s):

Thermal Conductivity ◽

Thermoelectric Materials ◽

Lattice Thermal Conductivity ◽

Natural Superlattice

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Metal phosphide CuP2 as a promising thermoelectric material: an insight from first-principles study

New Journal of Chemistry ◽

10.1039/d1nj03624f ◽

2021 ◽

Author(s):

Un-Gi Jong ◽

Chol-Hyok Ri ◽

Chol-Jin Pak ◽

Chol-Hyok Kim ◽

Stefaan Cottenier ◽

...

Keyword(s):

Thermal Conductivity ◽

Thermoelectric Material ◽

Thermoelectric Materials ◽

First Principles ◽

Lattice Thermal Conductivity ◽

Metal Phosphide ◽

First Principles Study ◽

Metal Phosphides ◽

Large Lattice

In the search for better thermoelectric materials, metal phosphides have not been considered to be viable candidates so far, due to their large lattice thermal conductivity. Here we study thermoelectric...

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