Enhancing the thermoelectric performance of Sn0.5Ge0.5Te via doping with Sb/Bi and alloying with Cu2Te: Optimization of transport properties and thermal conductivities

Song, Shaochang; Lo, Chun-Wan Timothy; Aminzare, M.; Tseng, Yu‐Chih; Valiyaveettil, Suneesh Meledath; Mozharivskyj, Yurij

doi:10.1039/d0dt00544d

Cited by 5 publications

(2 citation statements)

References 64 publications

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“…In particular, copper has been introduced in an ionic form within the SnTe matrix and as segregated Cu-based phases. Both interstitial Cu atoms and segregated Cu 2 Te/Cu 1.75 Te phases have been shown to effectively scatter phonons, resulting in extremely low lattice thermal conductivities down to 0.5 W m –1 K –1 . − …”

Section: Introductionmentioning

confidence: 99%

Bottom-Up Synthesis of SnTe-Based Thermoelectric Composites

Nan

Song

Chang

et al. 2023

ACS Appl. Mater. Interfaces

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There is a need for the development of lead-free thermoelectric materials for medium-/high-temperature applications. Here, we report a thiol-free tin telluride (SnTe) precursor that can be thermally decomposed to produce SnTe crystals with sizes ranging from tens to several hundreds of nanometers. We further engineer SnTe–Cu2SnTe3 nanocomposites with a homogeneous phase distribution by decomposing the liquid SnTe precursor containing a dispersion of Cu1.5Te colloidal nanoparticles. The presence of Cu within the SnTe and the segregated semimetallic Cu2SnTe3 phase effectively improves the electrical conductivity of SnTe while simultaneously reducing the lattice thermal conductivity without compromising the Seebeck coefficient. Overall, power factors up to 3.63 mW m–1 K–2 and thermoelectric figures of merit up to 1.04 are obtained at 823 K, which represent a 167% enhancement compared with pristine SnTe.

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Section: Introductionmentioning

confidence: 99%

Bottom-Up Synthesis of SnTe-Based Thermoelectric Composites

Nan

Song

Chang

et al. 2023

ACS Appl. Mater. Interfaces

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“…最后 , 在固溶体 (Sn 0.95 Ge 0.05 Te) 0.95 (Ag 2 Se) 0.05 的基础上, 继续采用Bi/Sn等摩尔置换, 再一次将构型熵从3.19 [28] 计算获得, 其中a为Seebeck系数. 晶格热导率通过公 ) [1,18,29,30] . 这可能是由于材料的制备工艺不同所致.…”

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Improvement of thermoelectric performance of SnTe-based solid solution by entropy engineering

Li¹,

Ying²,

Xie³

et al. 2022

Acta Phys. Sin.

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SnTe is a good alternative to PbTe in the thermoelectric (TE) applications, in that it is a compound with no toxic element Pb. Besides, the compound SnTe has a relatively narrow bandgap (0.3~0.4 eV) and at the same time high Sn vacancy concentration (Snv). Accordingly, it gives a high carrier concentration (1021 cm-3) at room temperature (RT), which is not favorable in thermoelectrics, thereby the regulation of both the electronic and phonon scattering mechanisms is strongly required. Up to date, there are many approaches to improve its TE performance. The typical examples are those involving the valence band convergence, nanostructuring, substitutional and interstitial defects, and lattice softening etc., which are all practical and effective to improve the TE performance of SnTe. However, we in this work take the entropy as an indicator to design the SnTe-based TE material with multicomponents and then optimize its TE performance. The detailed scheme involves the chemical composition design step by step. At first, SnTe alloys with 5% GaTe to form a solid solution Sn0.95Ge0.05Te, aiming to increase the solubility of the foreign species. The second step is to form another solid solution (Sn0.95Ge0.05Te)0.95(Ag2Se)0.05 via the alloying Sn0.95Ge0.05Te with 5% Ag2Se. The purpose of this step is to reduce the p-type carrier concentration of the system, as the species Ag2Se is a typical n-type semiconductor. The last step is to form a series of solid solutions (Sn0.95-xGe0.05BixTe)0.95(Ag2Se)0.05 by substituting different amount of Bi on Sn in (Sn0.95Ge0.05Te)0.95(Ag2Se)0.05, to further enhance the configurational entropy (ΔS). Because of the above approaches, both the carrier concentration and thermal conductivity reduce while the highest TE figure of merit (ZT) increases from 0.22 for the pristine SnTe to~0.8 for the alloy (Sn0.95-xGe0.05BixTe)0.95(Ag2Se)0.05 (x=0.075). This result proves that the entropy engineering is a practical way to improve the TE performance of SnTe and at the same time, it illustrates that it is very important to harmonize the entropy engineering with other electronic and phonon scattering mechanisms, in order to improve the TE performance of SnTe effectively.

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Converting n-type Co4Ge6Te6 skutterudite into p-type and enhancing its thermoelectric properties through Fe substitution

Song

Huang

Tseng

et al. 2022

Journal of Alloys and Compounds

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Enhancing the thermoelectric performance of Sn_0.5Ge_0.5Te via doping with Sb/Bi and alloying with Cu₂Te: Optimization of transport properties and thermal conductivities

Abstract: SnTe-based thermoelectric materials are studied as potential substitutes for PbTe. Ge and Bi substitutions combined with the Cu2Te alloying can significantly improve thermoelectric properties of SnTe as shown for (Sn0.5Ge0.5)0.91Bi0.06Te(Cu2Te)0.05.

Cited by 5 publications

References 64 publications

Bottom-Up Synthesis of SnTe-Based Thermoelectric Composites

Bottom-Up Synthesis of SnTe-Based Thermoelectric Composites

Improvement of thermoelectric performance of SnTe-based solid solution by entropy engineering

Converting n-type Co4Ge6Te6 skutterudite into p-type and enhancing its thermoelectric properties through Fe substitution

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