Rashba effect and point-defect engineering synergistically improve the thermoelectric performance of the entropy-stabilized Sn_0.8Ge_0.2Te_0.8Se_0.2 alloy

Fu, Liangwei1; Jin, Kangpeng1; Zhang, Dan2; Zhang, Chenghao1; Nie, Haonan1; Zhen, Zixiong1; Xiong, Pan1; Huang, Ming3; He, Jiaqing4; Xu, Biao1

2023-11-21

10.1039/d3ta03522k

JOURNAL OF MATERIALS CHEMISTRY A   影响因子和分区

2050-7488

2050-7496

High-entropy alloys (HEAs) extend the phase composition and thus enlarge the space for optimizing the performance of structural materials, catalysts, thermoelectrics, etc. To date, researchers have constructed SnTe-based HEAs mainly by alloying at the Sn cationic sublattice, leaving the anionic site untouched, which hinders performance optimization by exploring new phase compositions and band structures. Herein, we report that Sn1-yGeyTe0.80Se0.20 alloys can be stabilized by increasing the Ge content to larger than 5% (y > 5%), as a result of the entropy stabilization effect. Meanwhile, heavily co-alloying Ge and Se in SnTe breaks the inversion symmetry by lattice distortion, inducing the Rashba effect to split the L band and align multiple valence bands at valence band maximum (VBM). Additionally, introducing Sb and vacancies at the Sn site of Sn0.8Ge0.2Te0.8Se0.2 has enabled a high zT value of 1.3 at 823 K, which is comparable to those of cation-disordered SnTe-based high-entropy samples. This work reassures the choice of heavily alloying Se in SnTe-based materials and paves the way to design new SnTe-based high-entropy thermoelectric materials with multiple elements at both anionic and cationic sites.

SCI ; EI

英语

其他

L. W. F. would like to acknowledge the financial support from the National Natural Science Foundation of China (Grant No. 51802146) and the Innovation and Entrepreneurship Doctor in Jiangsu Province. B. X. acknowledges financial support from Innovation and[52173220] ; State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University[JCYJ20200109141205978] ; Science and Technology Innovation Committee Foundation of Shenzhen[202108]

Chemistry ; Energy & Fuels ; Materials Science

Chemistry, Physical ; Energy & Fuels ; Materials Science, Multidisciplinary

WOS:001099691500001

ROYAL SOC CHEMISTRY

20234715075460

Alloying elements ; Entropy ; Germanium ; Impurities ; IV-VI semiconductors ; Phase composition ; Selenium ; Thermoelectricity ; Tin ; Tin alloys ; Valence bands

Metallurgy:531.1 ; Tin and Alloys:546.2 ; Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals:549.3 ; Thermodynamics:641.1 ; Electricity: Basic Concepts and Phenomena:701.1 ; Semiconducting Materials:712.1 ; Materials Science:951

Web of Science

1.Nanjing Univ Sci & Technol, Sch Chem & Chem Engn, Nanjing 210094, Peoples R China
2.Hebei Univ, Coll Phys Sci & Technol, Key Lab High Precis Computat & Applicat Quantum Fi, Baoding 071002, Peoples R China
3.Nanjing Univ Sci & Technol, Sch Mat Sci & Engn, Nanjing 210094, Peoples R China
4.Southern Univ Sci & Technol, Dept Phys, Shenzhen Key Lab Thermoelectr Mat, Shenzhen 518055, Peoples R China

Fu, Liangwei,Jin, Kangpeng,Zhang, Dan,et al. Rashba effect and point-defect engineering synergistically improve the thermoelectric performance of the entropy-stabilized Sn_0.8Ge_0.2Te_0.8Se_0.2 alloy[J]. JOURNAL OF MATERIALS CHEMISTRY A,2023,11(45):24777-24788.

Fu, Liangwei.,Jin, Kangpeng.,Zhang, Dan.,Zhang, Chenghao.,Nie, Haonan.,...&Xu, Biao.(2023).Rashba effect and point-defect engineering synergistically improve the thermoelectric performance of the entropy-stabilized Sn_0.8Ge_0.2Te_0.8Se_0.2 alloy.JOURNAL OF MATERIALS CHEMISTRY A,11(45),24777-24788.

Fu, Liangwei,et al."Rashba effect and point-defect engineering synergistically improve the thermoelectric performance of the entropy-stabilized Sn_0.8Ge_0.2Te_0.8Se_0.2 alloy".JOURNAL OF MATERIALS CHEMISTRY A 11.45(2023):24777-24788.