Optimization of the Electronic Band Structure and the Lattice Thermal Conductivity of Solid Solutions According to Simple Calculations: A Canonical Example of the Mg2Si1-x-yGexSny Ternary Solid Solution

Kang Yin, Xianli Su, Yonggao Yan, Yonghui You, Qiang Zhang, Ctirad Uher, Mercouri G Kanatzidis, Xinfeng Tang

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The dependence of the electronic band structure of Mg2Si0.3-xGexSn0.7 and Mg2Si0.3GeySn0.7-y (0 ≤ x, and y ≤ 0.05) ternary solid solutions on composition and temperature is explained by a simple linear model, and the lattice thermal conductivity of solid solutions with different Si/Ge/Sn ratios is predicted by the Adachi model. The experimental results show excellent consistency with the calculations, which suggests that the approach might be suitable for describing the electronic band structure and the lattice thermal conductivity of other solid solutions using these simple calculations. Beyond this, it is observed that the immiscible gap in the Mg2Si1-xSnx binary system is narrowed via the introduction of Mg2Ge. Moreover, for the Sb-doped solid solutions Mg2.16(Si0.3GeySn0.7-y)0.98Sb0.02 (0 ≤ y ≤ 0.05), the energy offset between the light conduction band and the heavy conduction band at higher temperatures (500-800 K) will decrease with an increase in Ge content, thus making a contribution to the conduction band degeneracy and enhancing the power factor in turn. Meanwhile, mass fluctuation and strain field scattering processes are enhanced when Ge is substituted for Sn in Mg2.16(Si0.3GeySn0.7-y)0.98Sb0.02 (0 ≤ y ≤ 0.05) because of the large discrepancy between the mass and size of Ge and Sn, and the lattice thermal conductivity is decreased as a consequence. Thus, the thermoelectric performance is improved, with the figure of merit ZT being >1.45 at ∼750 K and the average ZT value being between 0.9 and 1.0 in the range of 300-800 K, which is one of the best results for Sb-doped Mg2Si1-x-yGexSny systems with a single phase.

Original languageEnglish
Pages (from-to)5538-5548
Number of pages11
JournalChemistry of Materials
Volume28
Issue number15
DOIs
Publication statusPublished - Aug 9 2016

Fingerprint

Thermal conductivity of solids
Crystal lattices
Band structure
Solid solutions
Conduction bands
Thermal conductivity
Scattering
Temperature
Chemical analysis

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

Cite this

Optimization of the Electronic Band Structure and the Lattice Thermal Conductivity of Solid Solutions According to Simple Calculations : A Canonical Example of the Mg2Si1-x-yGexSny Ternary Solid Solution. / Yin, Kang; Su, Xianli; Yan, Yonggao; You, Yonghui; Zhang, Qiang; Uher, Ctirad; Kanatzidis, Mercouri G; Tang, Xinfeng.

In: Chemistry of Materials, Vol. 28, No. 15, 09.08.2016, p. 5538-5548.

Research output: Contribution to journalArticle

@article{93f3fbcb7d1b40a3828dcc32ec6e3d57,
title = "Optimization of the Electronic Band Structure and the Lattice Thermal Conductivity of Solid Solutions According to Simple Calculations: A Canonical Example of the Mg2Si1-x-yGexSny Ternary Solid Solution",
abstract = "The dependence of the electronic band structure of Mg2Si0.3-xGexSn0.7 and Mg2Si0.3GeySn0.7-y (0 ≤ x, and y ≤ 0.05) ternary solid solutions on composition and temperature is explained by a simple linear model, and the lattice thermal conductivity of solid solutions with different Si/Ge/Sn ratios is predicted by the Adachi model. The experimental results show excellent consistency with the calculations, which suggests that the approach might be suitable for describing the electronic band structure and the lattice thermal conductivity of other solid solutions using these simple calculations. Beyond this, it is observed that the immiscible gap in the Mg2Si1-xSnx binary system is narrowed via the introduction of Mg2Ge. Moreover, for the Sb-doped solid solutions Mg2.16(Si0.3GeySn0.7-y)0.98Sb0.02 (0 ≤ y ≤ 0.05), the energy offset between the light conduction band and the heavy conduction band at higher temperatures (500-800 K) will decrease with an increase in Ge content, thus making a contribution to the conduction band degeneracy and enhancing the power factor in turn. Meanwhile, mass fluctuation and strain field scattering processes are enhanced when Ge is substituted for Sn in Mg2.16(Si0.3GeySn0.7-y)0.98Sb0.02 (0 ≤ y ≤ 0.05) because of the large discrepancy between the mass and size of Ge and Sn, and the lattice thermal conductivity is decreased as a consequence. Thus, the thermoelectric performance is improved, with the figure of merit ZT being >1.45 at ∼750 K and the average ZT value being between 0.9 and 1.0 in the range of 300-800 K, which is one of the best results for Sb-doped Mg2Si1-x-yGexSny systems with a single phase.",
author = "Kang Yin and Xianli Su and Yonggao Yan and Yonghui You and Qiang Zhang and Ctirad Uher and Kanatzidis, {Mercouri G} and Xinfeng Tang",
year = "2016",
month = "8",
day = "9",
doi = "10.1021/acs.chemmater.6b02308",
language = "English",
volume = "28",
pages = "5538--5548",
journal = "Chemistry of Materials",
issn = "0897-4756",
publisher = "American Chemical Society",
number = "15",

}

TY - JOUR

T1 - Optimization of the Electronic Band Structure and the Lattice Thermal Conductivity of Solid Solutions According to Simple Calculations

T2 - A Canonical Example of the Mg2Si1-x-yGexSny Ternary Solid Solution

AU - Yin, Kang

AU - Su, Xianli

AU - Yan, Yonggao

AU - You, Yonghui

AU - Zhang, Qiang

AU - Uher, Ctirad

AU - Kanatzidis, Mercouri G

AU - Tang, Xinfeng

PY - 2016/8/9

Y1 - 2016/8/9

N2 - The dependence of the electronic band structure of Mg2Si0.3-xGexSn0.7 and Mg2Si0.3GeySn0.7-y (0 ≤ x, and y ≤ 0.05) ternary solid solutions on composition and temperature is explained by a simple linear model, and the lattice thermal conductivity of solid solutions with different Si/Ge/Sn ratios is predicted by the Adachi model. The experimental results show excellent consistency with the calculations, which suggests that the approach might be suitable for describing the electronic band structure and the lattice thermal conductivity of other solid solutions using these simple calculations. Beyond this, it is observed that the immiscible gap in the Mg2Si1-xSnx binary system is narrowed via the introduction of Mg2Ge. Moreover, for the Sb-doped solid solutions Mg2.16(Si0.3GeySn0.7-y)0.98Sb0.02 (0 ≤ y ≤ 0.05), the energy offset between the light conduction band and the heavy conduction band at higher temperatures (500-800 K) will decrease with an increase in Ge content, thus making a contribution to the conduction band degeneracy and enhancing the power factor in turn. Meanwhile, mass fluctuation and strain field scattering processes are enhanced when Ge is substituted for Sn in Mg2.16(Si0.3GeySn0.7-y)0.98Sb0.02 (0 ≤ y ≤ 0.05) because of the large discrepancy between the mass and size of Ge and Sn, and the lattice thermal conductivity is decreased as a consequence. Thus, the thermoelectric performance is improved, with the figure of merit ZT being >1.45 at ∼750 K and the average ZT value being between 0.9 and 1.0 in the range of 300-800 K, which is one of the best results for Sb-doped Mg2Si1-x-yGexSny systems with a single phase.

AB - The dependence of the electronic band structure of Mg2Si0.3-xGexSn0.7 and Mg2Si0.3GeySn0.7-y (0 ≤ x, and y ≤ 0.05) ternary solid solutions on composition and temperature is explained by a simple linear model, and the lattice thermal conductivity of solid solutions with different Si/Ge/Sn ratios is predicted by the Adachi model. The experimental results show excellent consistency with the calculations, which suggests that the approach might be suitable for describing the electronic band structure and the lattice thermal conductivity of other solid solutions using these simple calculations. Beyond this, it is observed that the immiscible gap in the Mg2Si1-xSnx binary system is narrowed via the introduction of Mg2Ge. Moreover, for the Sb-doped solid solutions Mg2.16(Si0.3GeySn0.7-y)0.98Sb0.02 (0 ≤ y ≤ 0.05), the energy offset between the light conduction band and the heavy conduction band at higher temperatures (500-800 K) will decrease with an increase in Ge content, thus making a contribution to the conduction band degeneracy and enhancing the power factor in turn. Meanwhile, mass fluctuation and strain field scattering processes are enhanced when Ge is substituted for Sn in Mg2.16(Si0.3GeySn0.7-y)0.98Sb0.02 (0 ≤ y ≤ 0.05) because of the large discrepancy between the mass and size of Ge and Sn, and the lattice thermal conductivity is decreased as a consequence. Thus, the thermoelectric performance is improved, with the figure of merit ZT being >1.45 at ∼750 K and the average ZT value being between 0.9 and 1.0 in the range of 300-800 K, which is one of the best results for Sb-doped Mg2Si1-x-yGexSny systems with a single phase.

UR - http://www.scopus.com/inward/record.url?scp=84981537488&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84981537488&partnerID=8YFLogxK

U2 - 10.1021/acs.chemmater.6b02308

DO - 10.1021/acs.chemmater.6b02308

M3 - Article

AN - SCOPUS:84981537488

VL - 28

SP - 5538

EP - 5548

JO - Chemistry of Materials

JF - Chemistry of Materials

SN - 0897-4756

IS - 15

ER -