Weak Electron Phonon Coupling and Deep Level Impurity for High Thermoelectric Performance Pb1-xGaxTe

Xianli Su, Shiqiang Hao, Trevor P. Bailey, Si Wang, Ido Hadar, Gangjian Tan, Tze Bin Song, Qingjie Zhang, Ctirad Uher, Chris Wolverton, Xinfeng Tang, Mercouri G Kanatzidis

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

High ZT of 1.34 at 766 K and a record high average ZT above 1 in the temperature range of 300-864 K are attained in n-type PbTe by engineering the temperature-dependent carrier concentration and weakening electron-phonon coupling upon Ga doping. The experimental studies and first principles band structure calculations show that doping with Ga introduces a shallow level impurity contributing extrinsic carriers and imparts a deeper impurity level that ionizes at higher temperatures. This adjusts the carrier concentration closer to the temperature-dependent optimum and thus maximizes the power factor in a wide temperature range. The maximum power factor of 35 μW cm-1 K-2 is achieved for the Pb0.98Ga0.02Te compound, and is maintained over 20 μWcm-1 K-2 from 300 to 767 K. Band structure calculations and X-ray photoelectron spectroscopy corroborate the amphoteric role of Ga in PbTe as the origin of shallow and deep levels. Additionally, Ga doping weakens the electron-phonon coupling, leading to high carrier mobilities in excess of 1200 cm2 V-1 s-1. Enhanced point defect phonon scattering yields a reduced lattice thermal conductivity. This work provides a new avenue, beyond the conventional shallow level doping, for further improving the average ZT in thermoelectric materials.

Original languageEnglish
JournalAdvanced Energy Materials
DOIs
Publication statusAccepted/In press - Jan 1 2018

Fingerprint

Impurities
Doping (additives)
Electrons
Band structure
Carrier concentration
Temperature
Phonon scattering
Carrier mobility
Point defects
Crystal lattices
Thermal conductivity
X ray photoelectron spectroscopy

Keywords

  • Deep level impurities
  • Ga doping
  • PbTe
  • Thermoelectric properties

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)

Cite this

Weak Electron Phonon Coupling and Deep Level Impurity for High Thermoelectric Performance Pb1-xGaxTe. / Su, Xianli; Hao, Shiqiang; Bailey, Trevor P.; Wang, Si; Hadar, Ido; Tan, Gangjian; Song, Tze Bin; Zhang, Qingjie; Uher, Ctirad; Wolverton, Chris; Tang, Xinfeng; Kanatzidis, Mercouri G.

In: Advanced Energy Materials, 01.01.2018.

Research output: Contribution to journalArticle

Su, Xianli ; Hao, Shiqiang ; Bailey, Trevor P. ; Wang, Si ; Hadar, Ido ; Tan, Gangjian ; Song, Tze Bin ; Zhang, Qingjie ; Uher, Ctirad ; Wolverton, Chris ; Tang, Xinfeng ; Kanatzidis, Mercouri G. / Weak Electron Phonon Coupling and Deep Level Impurity for High Thermoelectric Performance Pb1-xGaxTe. In: Advanced Energy Materials. 2018.
@article{64868831e32146d082bac05ab8b38aca,
title = "Weak Electron Phonon Coupling and Deep Level Impurity for High Thermoelectric Performance Pb1-xGaxTe",
abstract = "High ZT of 1.34 at 766 K and a record high average ZT above 1 in the temperature range of 300-864 K are attained in n-type PbTe by engineering the temperature-dependent carrier concentration and weakening electron-phonon coupling upon Ga doping. The experimental studies and first principles band structure calculations show that doping with Ga introduces a shallow level impurity contributing extrinsic carriers and imparts a deeper impurity level that ionizes at higher temperatures. This adjusts the carrier concentration closer to the temperature-dependent optimum and thus maximizes the power factor in a wide temperature range. The maximum power factor of 35 μW cm-1 K-2 is achieved for the Pb0.98Ga0.02Te compound, and is maintained over 20 μWcm-1 K-2 from 300 to 767 K. Band structure calculations and X-ray photoelectron spectroscopy corroborate the amphoteric role of Ga in PbTe as the origin of shallow and deep levels. Additionally, Ga doping weakens the electron-phonon coupling, leading to high carrier mobilities in excess of 1200 cm2 V-1 s-1. Enhanced point defect phonon scattering yields a reduced lattice thermal conductivity. This work provides a new avenue, beyond the conventional shallow level doping, for further improving the average ZT in thermoelectric materials.",
keywords = "Deep level impurities, Ga doping, PbTe, Thermoelectric properties",
author = "Xianli Su and Shiqiang Hao and Bailey, {Trevor P.} and Si Wang and Ido Hadar and Gangjian Tan and Song, {Tze Bin} and Qingjie Zhang and Ctirad Uher and Chris Wolverton and Xinfeng Tang and Kanatzidis, {Mercouri G}",
year = "2018",
month = "1",
day = "1",
doi = "10.1002/aenm.201800659",
language = "English",
journal = "Advanced Energy Materials",
issn = "1614-6832",
publisher = "Wiley-VCH Verlag",

}

TY - JOUR

T1 - Weak Electron Phonon Coupling and Deep Level Impurity for High Thermoelectric Performance Pb1-xGaxTe

AU - Su, Xianli

AU - Hao, Shiqiang

AU - Bailey, Trevor P.

AU - Wang, Si

AU - Hadar, Ido

AU - Tan, Gangjian

AU - Song, Tze Bin

AU - Zhang, Qingjie

AU - Uher, Ctirad

AU - Wolverton, Chris

AU - Tang, Xinfeng

AU - Kanatzidis, Mercouri G

PY - 2018/1/1

Y1 - 2018/1/1

N2 - High ZT of 1.34 at 766 K and a record high average ZT above 1 in the temperature range of 300-864 K are attained in n-type PbTe by engineering the temperature-dependent carrier concentration and weakening electron-phonon coupling upon Ga doping. The experimental studies and first principles band structure calculations show that doping with Ga introduces a shallow level impurity contributing extrinsic carriers and imparts a deeper impurity level that ionizes at higher temperatures. This adjusts the carrier concentration closer to the temperature-dependent optimum and thus maximizes the power factor in a wide temperature range. The maximum power factor of 35 μW cm-1 K-2 is achieved for the Pb0.98Ga0.02Te compound, and is maintained over 20 μWcm-1 K-2 from 300 to 767 K. Band structure calculations and X-ray photoelectron spectroscopy corroborate the amphoteric role of Ga in PbTe as the origin of shallow and deep levels. Additionally, Ga doping weakens the electron-phonon coupling, leading to high carrier mobilities in excess of 1200 cm2 V-1 s-1. Enhanced point defect phonon scattering yields a reduced lattice thermal conductivity. This work provides a new avenue, beyond the conventional shallow level doping, for further improving the average ZT in thermoelectric materials.

AB - High ZT of 1.34 at 766 K and a record high average ZT above 1 in the temperature range of 300-864 K are attained in n-type PbTe by engineering the temperature-dependent carrier concentration and weakening electron-phonon coupling upon Ga doping. The experimental studies and first principles band structure calculations show that doping with Ga introduces a shallow level impurity contributing extrinsic carriers and imparts a deeper impurity level that ionizes at higher temperatures. This adjusts the carrier concentration closer to the temperature-dependent optimum and thus maximizes the power factor in a wide temperature range. The maximum power factor of 35 μW cm-1 K-2 is achieved for the Pb0.98Ga0.02Te compound, and is maintained over 20 μWcm-1 K-2 from 300 to 767 K. Band structure calculations and X-ray photoelectron spectroscopy corroborate the amphoteric role of Ga in PbTe as the origin of shallow and deep levels. Additionally, Ga doping weakens the electron-phonon coupling, leading to high carrier mobilities in excess of 1200 cm2 V-1 s-1. Enhanced point defect phonon scattering yields a reduced lattice thermal conductivity. This work provides a new avenue, beyond the conventional shallow level doping, for further improving the average ZT in thermoelectric materials.

KW - Deep level impurities

KW - Ga doping

KW - PbTe

KW - Thermoelectric properties

UR - http://www.scopus.com/inward/record.url?scp=85047542088&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85047542088&partnerID=8YFLogxK

U2 - 10.1002/aenm.201800659

DO - 10.1002/aenm.201800659

M3 - Article

JO - Advanced Energy Materials

JF - Advanced Energy Materials

SN - 1614-6832

ER -