Designing High Entropy Structure in Thermoelectrics

doi:10.15541/jim20200659

Abstract

Abstract:

With the fascinating properties observed in high entropy alloys, the idea of high entropy design has been applied to many material fields. Thermoelectric materials have some particular requirements for high entropy structure according to their transport characteristics. Here, we revealed that the high entropy structure for thermoelectrics required less lattice distortion, and the doping sites should have less influence on the Fermi surface. In the designed compound of Cu_0.8Ag_0.2Zn_0.1Ga_0.4Ge_0.1In_0.4Te₂, the room-temperature thermal conductivity is reduced by 80% as compared to the matrix, and the maximum ZT is enhanced to 1.02. In SnTe, the solid solution of AgSbSe₂ reduces the room-temperature thermal conductivity by 80%, reaching 1.3 W·m^-1·K^-1. This study shows that the high entropy structure following the proposed designing rules could be an important strategy for thermoelectrics.

Key words: high entropy alloys, thermoelectrics, Gibbs free energy, high entropy structure

CLC Number:

TQ174

CAI Jianfeng, WANG Hongxiang, LIU Guoqiang, JIANG Jun. Designing High Entropy Structure in Thermoelectrics[J]. Journal of Inorganic Materials, 2021, 36(4): 399-404.

Figures/Tables 7

Fig. 1 Crystal structure (a) and electronic structure (b) of CuInTe2

Fig. 2 Density of State (DOS) of CuInTe2, including the partial DOS for Cu-d and Te-p orbitals

Fig. 3 XRD patterns for CuInTe2 and its high entropy solid solutions

Fig. 4 Electrical conductivity (a) and Seebeck coefficient (b) for CuInTe2 and its high entropy solid solutions

Table 1 Carrier concentrations and mobilities of samples with different components at room temperature

Sample	n_H/cm^-3	μ_H/ (cm²·V^-1·s^-1)
CuInTe₂	3.1×10¹⁸	78.1
Cu_0.5Ag_0.5Ga_0.5In_0.5Te₂	1.3×10¹⁸	10.4
Cu_0.5Ag_0.5Zn_0.25Ga_0.25Ge_0.25In_0.25Te₂	5.6×10¹⁹	1.2
Cu_0.8Ag_0.2Zn_0.1Ga_0.4Ge_0.1In_0.4Te₂	3.2×10¹⁹	17.8

Fig. 5 Thermal conductivity (a) and ZT (b) for CuInTe2 and its high entropy solid solutions

Fig. 6 Electrical conductivity (a) and thermal conductivity (b) for SnTe-AgSbSe2 solid solutions[28] Solid lines refer to total thermal conductivity, dash lines refer to lattice thermal conductivity. and black, red and green refer to SnTe, SnTe+ 10%AgSbSe2 and SnTe+20%AgSbSe2, respectively

References 30

[1]	GEORGEE P, RAABE D, RITCHIER O. High-entropy alloys. Nature Reviews Materials, 2019,4(8):515-534.
[2]	MIRACLED B, SENKOVO N. A critical review of high entropy alloys and related concepts. Acta Mater., 2017,122:448-511.
[3]	YEH J W, CHEN S K, LIN S J, et al. Nanostructured high-entropy alloying with multiple principal elements: novel alloy design concepts and outcomes. Adv. Eng. Mater., 2004,6(5):299-303.
[4]	GLUDOVATZ B, HOHENWARTER A, CATOOR D, et al. A fracture-resistant high-entropy alloy for cryogenic applications. Science, 2014,345(6201):1153-1158. URL PMID
[5]	LI Z, PRADEEPK G, DENG Y, et al. Metastable high-entropy dual-phase alloys overcome the strength-ductility trade-off. Nature, 2016,534(7606):306-307.
[6]	YOUSSEF K M, ZADDACH A J, NIU C, et al. A novel low-density, high-hardness, high-entropy alloy with close-packed single-phase nanocrystalline structures. Materials Research Letters, 2014,3(2):95-99.
[7]	ZHANG Y, ZUO T T, TANG Z, et al. Microstructures and properties of high-entropy alloys. Prog. Mater. Sci., 2014,61:1-93.
[8]	SHI Y Z, YANG B LIAW P. Corrosion-resistant high-entropy alloys: a review. Metals-Basel, 2017,7(92):43-1-18.
[9]	SENKOV O N, WILKS G B, Miracle D B, et al. Refractory high-entropy alloys. Intermetallics, 2010,18(9):1758-1765.
[10]	HSU C Y, JUAN C C, WANG W R, et al. On the superior hot hardness and softening resistance of AlCoCr_xFeMo_0.5Ni high- entropy alloys. Materials Science and Engineering: A, 2011,528(10/11):3581-3588.
[11]	OIKAWA K, ITO W, IMANO Y, et al. Effect of magnetic field on martensitic transition of Ni₄₆Mn₄₁In₁₃ heusler alloy. Appl. Phys. Lett., 2006,88(12):122507-1-3.
[12]	ZHANG Y, ZUO T, CHENG Y, et al. High-entropy alloys with high saturation magnetization, electrical resistivity, and malleability. Sci. Rep., 2013,3:1455-1-7. URL PMID
[13]	BÉRARDAN D, FRANGER S, DRAGOE D, et al. Colossal dielectric constant in high entropy oxides. Physica Status Solidi-Rapid Research Letters, 2016,10(4):328-333.
[14]	SHAFEIE S, GUO S, HU Q, et al. High-entropy alloys as high- temperature thermoelectric materials. J. Appl. Phys., 2015,118(18):184905-1-10.
[15]	WEI P C, LIAO C N, WU H J, et al. Thermodynamic routes to ultralow thermal conductivity and high thermoelectric performance. Adv. Mater., 2020,32(12):1906457-1-10.
[16]	TSAI M H. Three strategies for the design of advanced high- entropy alloys. Entropy, 2016,18(7):252-1-14.
[17]	TSAI M H, YEH J W. High-entropy alloys: a critical review. Materials Research Letters, 2014,2(3):107-123.
[18]	BELL L E. Cooling, heating, generating power, and recovering waste heat with thermoelectric systems. Science, 2008,321(12):1457-1461.
[19]	SNYDER G J. Complex strucure thermoelectric meterial. Nat. Mater., 2008,7(2):105-114. DOI URL PMID
[20]	SOOTSMAN J R, CHUNG D Y, KANATZIDIS M G. New and old concepts in thermoelectric materials. Angewandte Chemie International Edition, 2009,48(46):8616-8639. URL PMID
[21]	ZHANG H, LEE G, FONSECA A F, et al. Isotope effect on the thermal conductivity of graphene. Journal of Nanomaterials, 2010,2010:537657-1-5.
[22]	LIU R, XI L, LIU H, et al. Ternary compound CuInTe₂: a promising thermoelectric material with diamond-like structure. Chem. Commun., 2012,48(32):3818-3820.
[23]	PLIRDPRING T, KUROSAKI K, KOSUGA A, et al. Chalcopyrite CuGaTe₂: a high-efficiency bulk thermoelectric material. Adv. Mater., 2012,24(27):3622-3626. URL PMID
[24]	XI L, ZHANGY B, SHIX Y, et al. Chemical bonding, conductive network, and thermoelectric performance of the ternary semiconductors Cu₂SnX₃ (X=Se, S) from first principles. Phys. Rev. B, 2012,86(15):155201-155215.
[25]	SKOUGE J, CAINJ D, MORELLID T. High thermoelectric figure of merit in the Cu₃SbSe₄-Cu₃SbS₄solid solution. Appl. Phys. Lett., 2011, 98(26):261911-1-3. DOI URL
[26]	LIU R, CHEN H, ZHAO K, et al. Entropy as a gene-like performance indicator promoting thermoelectric materials. Adv. Mater., 2017, 29(38):1702712-7-7.
[27]	HU L, ZHANG Y, WU H, et al. Entropy engineering of SnTe: multi-principal-element alloying leading to ultralow lattice thermal conductivity and state-of-the-art thermoelectric performance. Adv. Energy Mater., 2018, 8(29):1802116-1-14.
[28]	LIN S X, TAN X J, SHAO H Z, et al. Ultralow lattice thermal conductivity in SnTe by manipulating the electron-phonon coupling. The Journal of Physical Chemistry C, 2019,123(26):15996-16002. DOI URL
[29]	TAN G, HAO S, HANUS R, et al. High thermoelectric performance in SnTe-AgSbTe₂ alloys from lattice softening, giant phonon-vacancy scattering, and valence band convergence. ACS. Energy Lett., 2018,3(3):705-712.
[30]	HARRISON W. Elementary Electronic Structure. London: World Scientific Publishing Company, 2004.