Achieving band convergence by tuning the bonding ionicity in n-type Mg 3 Sb 2

Xin Sun, Xin Li, Jiong Yang*, Jinyang Xi, Ryky Nelson, Christina Ertural, Richard Dronskowski, Weishu Liu, Gerald Jeffrey Snyder, David J. Singh, Wenqing Zhang

*Corresponding author for this work

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Identifying strategies for beneficial band engineering is crucial for the optimization of thermoelectric (TE) materials. In this study, we demonstrate the beneficial effects of ionic dopants on n-type Mg 3 Sb 2 . Using the band-resolved projected crystal orbital Hamilton population, the covalent characters of the bonding between Mg atoms at different sites are observed. By partially substituting the Mg at the octahedral sites with more ionic dopants, such as Ca and Yb, the conduction band minimum (CBM) of Mg 3 Sb 2 is altered to be more anisotropic with an enhanced band degeneracy of 7. The CBM density of states of doped Mg 3 Sb 2 with these dopants is significantly enlarged by band engineering. The improved Seebeck coefficients and power factors, together with the reduced lattice thermal conductivities, imply that the partial introduction of more ionic dopants in Mg 3 Sb 2 is a general solution for its n-type TE performance.

Original languageEnglish (US)
JournalJournal of computational chemistry
DOIs
StatePublished - Jan 1 2019

Fingerprint

Tuning
Doping (additives)
Conduction bands
Conduction
Seebeck coefficient
Engineering
Thermal conductivity
Density of States
Thermal Conductivity
Degeneracy
General Solution
Atoms
Crystals
Crystal
Partial
Imply
Optimization
Coefficient
Demonstrate

Keywords

  • Mg Sb
  • band engineering
  • band-resolved COHP
  • bonding ionicity
  • thermoelectric

ASJC Scopus subject areas

  • Chemistry(all)
  • Computational Mathematics

Cite this

Sun, Xin ; Li, Xin ; Yang, Jiong ; Xi, Jinyang ; Nelson, Ryky ; Ertural, Christina ; Dronskowski, Richard ; Liu, Weishu ; Snyder, Gerald Jeffrey ; Singh, David J. ; Zhang, Wenqing. / Achieving band convergence by tuning the bonding ionicity in n-type Mg 3 Sb 2 In: Journal of computational chemistry. 2019.
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abstract = "Identifying strategies for beneficial band engineering is crucial for the optimization of thermoelectric (TE) materials. In this study, we demonstrate the beneficial effects of ionic dopants on n-type Mg 3 Sb 2 . Using the band-resolved projected crystal orbital Hamilton population, the covalent characters of the bonding between Mg atoms at different sites are observed. By partially substituting the Mg at the octahedral sites with more ionic dopants, such as Ca and Yb, the conduction band minimum (CBM) of Mg 3 Sb 2 is altered to be more anisotropic with an enhanced band degeneracy of 7. The CBM density of states of doped Mg 3 Sb 2 with these dopants is significantly enlarged by band engineering. The improved Seebeck coefficients and power factors, together with the reduced lattice thermal conductivities, imply that the partial introduction of more ionic dopants in Mg 3 Sb 2 is a general solution for its n-type TE performance.",
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author = "Xin Sun and Xin Li and Jiong Yang and Jinyang Xi and Ryky Nelson and Christina Ertural and Richard Dronskowski and Weishu Liu and Snyder, {Gerald Jeffrey} and Singh, {David J.} and Wenqing Zhang",
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Sun, X, Li, X, Yang, J, Xi, J, Nelson, R, Ertural, C, Dronskowski, R, Liu, W, Snyder, GJ, Singh, DJ & Zhang, W 2019, ' Achieving band convergence by tuning the bonding ionicity in n-type Mg 3 Sb 2 ', Journal of computational chemistry. https://doi.org/10.1002/jcc.25822

Achieving band convergence by tuning the bonding ionicity in n-type Mg 3 Sb 2 . / Sun, Xin; Li, Xin; Yang, Jiong; Xi, Jinyang; Nelson, Ryky; Ertural, Christina; Dronskowski, Richard; Liu, Weishu; Snyder, Gerald Jeffrey; Singh, David J.; Zhang, Wenqing.

In: Journal of computational chemistry, 01.01.2019.

Research output: Contribution to journalArticle

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AU - Sun, Xin

AU - Li, Xin

AU - Yang, Jiong

AU - Xi, Jinyang

AU - Nelson, Ryky

AU - Ertural, Christina

AU - Dronskowski, Richard

AU - Liu, Weishu

AU - Snyder, Gerald Jeffrey

AU - Singh, David J.

AU - Zhang, Wenqing

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N2 - Identifying strategies for beneficial band engineering is crucial for the optimization of thermoelectric (TE) materials. In this study, we demonstrate the beneficial effects of ionic dopants on n-type Mg 3 Sb 2 . Using the band-resolved projected crystal orbital Hamilton population, the covalent characters of the bonding between Mg atoms at different sites are observed. By partially substituting the Mg at the octahedral sites with more ionic dopants, such as Ca and Yb, the conduction band minimum (CBM) of Mg 3 Sb 2 is altered to be more anisotropic with an enhanced band degeneracy of 7. The CBM density of states of doped Mg 3 Sb 2 with these dopants is significantly enlarged by band engineering. The improved Seebeck coefficients and power factors, together with the reduced lattice thermal conductivities, imply that the partial introduction of more ionic dopants in Mg 3 Sb 2 is a general solution for its n-type TE performance.

AB - Identifying strategies for beneficial band engineering is crucial for the optimization of thermoelectric (TE) materials. In this study, we demonstrate the beneficial effects of ionic dopants on n-type Mg 3 Sb 2 . Using the band-resolved projected crystal orbital Hamilton population, the covalent characters of the bonding between Mg atoms at different sites are observed. By partially substituting the Mg at the octahedral sites with more ionic dopants, such as Ca and Yb, the conduction band minimum (CBM) of Mg 3 Sb 2 is altered to be more anisotropic with an enhanced band degeneracy of 7. The CBM density of states of doped Mg 3 Sb 2 with these dopants is significantly enlarged by band engineering. The improved Seebeck coefficients and power factors, together with the reduced lattice thermal conductivities, imply that the partial introduction of more ionic dopants in Mg 3 Sb 2 is a general solution for its n-type TE performance.

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