Enhanced Density-of-States Effective Mass and Strained Endotaxial Nanostructures in Sb-Doped Pb 0.97 Cd 0.03 Te Thermoelectric Alloys

Gangjian Tan, Xiaomi Zhang, Shiqiang Hao, Hang Chi, Trevor P. Bailey, Xianli Su, Ctirad Uher, Vinayak P. Dravid, Chris Wolverton, Mercouri G Kanatzidis

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Here we report that CdTe alloying and Sb doping increase the density-of-states effective mass and introduce endotaxial nanostructuring in n-type PbTe, resulting in enhanced thermoelectric performance. A prior theoretical prediction for the presence of resonance states in the conduction band of this system, however, could not be confirmed. An amount of 3 mol % CdTe alloying widens the band gap of PbTe by 50%, leading to enhanced carrier effective mass and Seebeck coefficient. This effect is even more pronounced at high temperatures where the solubility of CdTe increases. At 800 K, when the carrier concentration is the same (4 × 10 19 cm -3 ), the Seebeck coefficient of CdTe-alloyed PbTe is -195 μV K -1 , 16% higher than that of the Cd-free control sample (-168 μV K -1 ). Sb doping considerably increases the electron concentration of Pb 0.97 Cd 0.03 Te, giving rise to optimized power factors of ∼17 μW cm -1 K -2 at 800 K. More importantly, Sb induces strained endotaxial nanostructures evenly distributed in the matrix. These Sb-rich nanostructures account for the ∼40% reduction in the lattice thermal conductivity over the whole measured temperature range. As a result, a maximum ZT of 1.2 is attained at 750 K in 0.5 mol % Sb-doped Pb 0.97 Cd 0.03 Te alloys.

Original languageEnglish
Pages (from-to)9197-9204
Number of pages8
JournalACS Applied Materials and Interfaces
Volume11
Issue number9
DOIs
Publication statusPublished - Mar 6 2019

Fingerprint

Seebeck coefficient
Alloying
Nanostructures
Doping (additives)
Conduction bands
Carrier concentration
Thermal conductivity
Energy gap
Solubility
Temperature
Electrons
cadmium telluride

Keywords

  • electronic structure
  • lead telluride
  • nanostructuring
  • thermal conductivity
  • thermoelectric

ASJC Scopus subject areas

  • Materials Science(all)

Cite this

Enhanced Density-of-States Effective Mass and Strained Endotaxial Nanostructures in Sb-Doped Pb 0.97 Cd 0.03 Te Thermoelectric Alloys . / Tan, Gangjian; Zhang, Xiaomi; Hao, Shiqiang; Chi, Hang; Bailey, Trevor P.; Su, Xianli; Uher, Ctirad; Dravid, Vinayak P.; Wolverton, Chris; Kanatzidis, Mercouri G.

In: ACS Applied Materials and Interfaces, Vol. 11, No. 9, 06.03.2019, p. 9197-9204.

Research output: Contribution to journalArticle

Tan, Gangjian ; Zhang, Xiaomi ; Hao, Shiqiang ; Chi, Hang ; Bailey, Trevor P. ; Su, Xianli ; Uher, Ctirad ; Dravid, Vinayak P. ; Wolverton, Chris ; Kanatzidis, Mercouri G. / Enhanced Density-of-States Effective Mass and Strained Endotaxial Nanostructures in Sb-Doped Pb 0.97 Cd 0.03 Te Thermoelectric Alloys In: ACS Applied Materials and Interfaces. 2019 ; Vol. 11, No. 9. pp. 9197-9204.
@article{de9eeec547ba4daabe410883270586cf,
title = "Enhanced Density-of-States Effective Mass and Strained Endotaxial Nanostructures in Sb-Doped Pb 0.97 Cd 0.03 Te Thermoelectric Alloys",
abstract = "Here we report that CdTe alloying and Sb doping increase the density-of-states effective mass and introduce endotaxial nanostructuring in n-type PbTe, resulting in enhanced thermoelectric performance. A prior theoretical prediction for the presence of resonance states in the conduction band of this system, however, could not be confirmed. An amount of 3 mol {\%} CdTe alloying widens the band gap of PbTe by 50{\%}, leading to enhanced carrier effective mass and Seebeck coefficient. This effect is even more pronounced at high temperatures where the solubility of CdTe increases. At 800 K, when the carrier concentration is the same (4 × 10 19 cm -3 ), the Seebeck coefficient of CdTe-alloyed PbTe is -195 μV K -1 , 16{\%} higher than that of the Cd-free control sample (-168 μV K -1 ). Sb doping considerably increases the electron concentration of Pb 0.97 Cd 0.03 Te, giving rise to optimized power factors of ∼17 μW cm -1 K -2 at 800 K. More importantly, Sb induces strained endotaxial nanostructures evenly distributed in the matrix. These Sb-rich nanostructures account for the ∼40{\%} reduction in the lattice thermal conductivity over the whole measured temperature range. As a result, a maximum ZT of 1.2 is attained at 750 K in 0.5 mol {\%} Sb-doped Pb 0.97 Cd 0.03 Te alloys.",
keywords = "electronic structure, lead telluride, nanostructuring, thermal conductivity, thermoelectric",
author = "Gangjian Tan and Xiaomi Zhang and Shiqiang Hao and Hang Chi and Bailey, {Trevor P.} and Xianli Su and Ctirad Uher and Dravid, {Vinayak P.} and Chris Wolverton and Kanatzidis, {Mercouri G}",
year = "2019",
month = "3",
day = "6",
doi = "10.1021/acsami.8b21524",
language = "English",
volume = "11",
pages = "9197--9204",
journal = "ACS applied materials & interfaces",
issn = "1944-8244",
publisher = "American Chemical Society",
number = "9",

}

TY - JOUR

T1 - Enhanced Density-of-States Effective Mass and Strained Endotaxial Nanostructures in Sb-Doped Pb 0.97 Cd 0.03 Te Thermoelectric Alloys

AU - Tan, Gangjian

AU - Zhang, Xiaomi

AU - Hao, Shiqiang

AU - Chi, Hang

AU - Bailey, Trevor P.

AU - Su, Xianli

AU - Uher, Ctirad

AU - Dravid, Vinayak P.

AU - Wolverton, Chris

AU - Kanatzidis, Mercouri G

PY - 2019/3/6

Y1 - 2019/3/6

N2 - Here we report that CdTe alloying and Sb doping increase the density-of-states effective mass and introduce endotaxial nanostructuring in n-type PbTe, resulting in enhanced thermoelectric performance. A prior theoretical prediction for the presence of resonance states in the conduction band of this system, however, could not be confirmed. An amount of 3 mol % CdTe alloying widens the band gap of PbTe by 50%, leading to enhanced carrier effective mass and Seebeck coefficient. This effect is even more pronounced at high temperatures where the solubility of CdTe increases. At 800 K, when the carrier concentration is the same (4 × 10 19 cm -3 ), the Seebeck coefficient of CdTe-alloyed PbTe is -195 μV K -1 , 16% higher than that of the Cd-free control sample (-168 μV K -1 ). Sb doping considerably increases the electron concentration of Pb 0.97 Cd 0.03 Te, giving rise to optimized power factors of ∼17 μW cm -1 K -2 at 800 K. More importantly, Sb induces strained endotaxial nanostructures evenly distributed in the matrix. These Sb-rich nanostructures account for the ∼40% reduction in the lattice thermal conductivity over the whole measured temperature range. As a result, a maximum ZT of 1.2 is attained at 750 K in 0.5 mol % Sb-doped Pb 0.97 Cd 0.03 Te alloys.

AB - Here we report that CdTe alloying and Sb doping increase the density-of-states effective mass and introduce endotaxial nanostructuring in n-type PbTe, resulting in enhanced thermoelectric performance. A prior theoretical prediction for the presence of resonance states in the conduction band of this system, however, could not be confirmed. An amount of 3 mol % CdTe alloying widens the band gap of PbTe by 50%, leading to enhanced carrier effective mass and Seebeck coefficient. This effect is even more pronounced at high temperatures where the solubility of CdTe increases. At 800 K, when the carrier concentration is the same (4 × 10 19 cm -3 ), the Seebeck coefficient of CdTe-alloyed PbTe is -195 μV K -1 , 16% higher than that of the Cd-free control sample (-168 μV K -1 ). Sb doping considerably increases the electron concentration of Pb 0.97 Cd 0.03 Te, giving rise to optimized power factors of ∼17 μW cm -1 K -2 at 800 K. More importantly, Sb induces strained endotaxial nanostructures evenly distributed in the matrix. These Sb-rich nanostructures account for the ∼40% reduction in the lattice thermal conductivity over the whole measured temperature range. As a result, a maximum ZT of 1.2 is attained at 750 K in 0.5 mol % Sb-doped Pb 0.97 Cd 0.03 Te alloys.

KW - electronic structure

KW - lead telluride

KW - nanostructuring

KW - thermal conductivity

KW - thermoelectric

UR - http://www.scopus.com/inward/record.url?scp=85062584771&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85062584771&partnerID=8YFLogxK

U2 - 10.1021/acsami.8b21524

DO - 10.1021/acsami.8b21524

M3 - Article

C2 - 30715833

AN - SCOPUS:85062584771

VL - 11

SP - 9197

EP - 9204

JO - ACS applied materials & interfaces

JF - ACS applied materials & interfaces

SN - 1944-8244

IS - 9

ER -