High Figure of Merit in Gallium-Doped Nanostructured n-Type PbTe- xGeTe with Midgap States

Zhong Zhen Luo; Songting Cai; Shiqiang Hao; Trevor P. Bailey; Xianli Su; Ioannis Spanopoulos; Ido Hadar; Gangjian Tan; Yubo Luo; Jianwei Xu; Ctirad Uher; Christopher Wolverton; Vinayak P. Dravid; Qingyu Yan; Mercouri G. Kanatzidis

doi:10.1021/jacs.9b09249

High Figure of Merit in Gallium-Doped Nanostructured n-Type PbTe- xGeTe with Midgap States

Zhong Zhen Luo, Songting Cai, Shiqiang Hao, Trevor P. Bailey, Xianli Su, Ioannis Spanopoulos, Ido Hadar, Gangjian Tan, Yubo Luo, Jianwei Xu, Ctirad Uher, Christopher Wolverton, Vinayak P. Dravid, Qingyu Yan, Mercouri G. Kanatzidis

Research output: Contribution to journal › Article › peer-review

Abstract

PbTe-based thermoelectric materials are some of the most promising for converting heat into electricity, but their n-type versions still lag in performance the p-type ones. Here, we introduce midgap states and nanoscale precipitates using Ga-doping and GeTe-alloying to considerably improve the performance of n-type PbTe. The GeTe alloying significantly enlarges the energy band gap of PbTe and subsequent Ga doping introduces special midgap states that lead to an increased density of states (DOS) effective mass and enhanced Seebeck coefficients. Moreover, the nucleated Ga₂Te₃ nanoscale precipitates and off-center discordant Ge atoms in the PbTe matrix cause intense phonon scattering, strongly reducing the thermal conductivity (∼0.65 W m^-1 K^-1 at 623 K). As a result, a high room-temperature thermoelectric figure of merit ZT ∼0.59 and a peak ZT_max of ∼1.47 at 673 K were obtained for the Pb_0.98Ga_0.02Te-5%GeTe. The ZT_avg value that is most relevant for devices is ∼1.27 from 400 to 773 K, the highest recorded value for n-type PbTe.

Original language	English
Pages (from-to)	16169-16177
Number of pages	9
Journal	Journal of the American Chemical Society
Volume	141
Issue number	40
DOIs	https://doi.org/10.1021/jacs.9b09249
State	Published - 9 Oct 2019
Externally published	Yes

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This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 7 Affordable and Clean Energy

All Science Journal Classification (ASJC) codes

Catalysis
General Chemistry
Biochemistry
Colloid and Surface Chemistry

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10.1021/jacs.9b09249

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Luo, Z. Z., Cai, S., Hao, S., Bailey, T. P., Su, X., Spanopoulos, I., Hadar, I., Tan, G., Luo, Y., Xu, J., Uher, C., Wolverton, C., Dravid, V. P., Yan, Q., & Kanatzidis, M. G. (2019). High Figure of Merit in Gallium-Doped Nanostructured n-Type PbTe- xGeTe with Midgap States. Journal of the American Chemical Society, 141(40), 16169-16177. https://doi.org/10.1021/jacs.9b09249

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title = "High Figure of Merit in Gallium-Doped Nanostructured n-Type PbTe- xGeTe with Midgap States",

abstract = "PbTe-based thermoelectric materials are some of the most promising for converting heat into electricity, but their n-type versions still lag in performance the p-type ones. Here, we introduce midgap states and nanoscale precipitates using Ga-doping and GeTe-alloying to considerably improve the performance of n-type PbTe. The GeTe alloying significantly enlarges the energy band gap of PbTe and subsequent Ga doping introduces special midgap states that lead to an increased density of states (DOS) effective mass and enhanced Seebeck coefficients. Moreover, the nucleated Ga2Te3 nanoscale precipitates and off-center discordant Ge atoms in the PbTe matrix cause intense phonon scattering, strongly reducing the thermal conductivity (∼0.65 W m-1 K-1 at 623 K). As a result, a high room-temperature thermoelectric figure of merit ZT ∼0.59 and a peak ZTmax of ∼1.47 at 673 K were obtained for the Pb0.98Ga0.02Te-5\%GeTe. The ZTavg value that is most relevant for devices is ∼1.27 from 400 to 773 K, the highest recorded value for n-type PbTe.",

author = "Luo, \{Zhong Zhen\} and Songting Cai and Shiqiang Hao and Bailey, \{Trevor P.\} and Xianli Su and Ioannis Spanopoulos and Ido Hadar and Gangjian Tan and Yubo Luo and Jianwei Xu and Ctirad Uher and Christopher Wolverton and Dravid, \{Vinayak P.\} and Qingyu Yan and Kanatzidis, \{Mercouri G.\}",

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doi = "10.1021/jacs.9b09249",

language = "الإنجليزيّة",

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pages = "16169--16177",

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TY - JOUR

T1 - High Figure of Merit in Gallium-Doped Nanostructured n-Type PbTe- xGeTe with Midgap States

AU - Luo, Zhong Zhen

AU - Cai, Songting

AU - Hao, Shiqiang

AU - Bailey, Trevor P.

AU - Su, Xianli

AU - Spanopoulos, Ioannis

AU - Hadar, Ido

AU - Tan, Gangjian

AU - Luo, Yubo

AU - Xu, Jianwei

AU - Uher, Ctirad

AU - Wolverton, Christopher

AU - Dravid, Vinayak P.

AU - Yan, Qingyu

AU - Kanatzidis, Mercouri G.

PY - 2019/10/9

Y1 - 2019/10/9

N2 - PbTe-based thermoelectric materials are some of the most promising for converting heat into electricity, but their n-type versions still lag in performance the p-type ones. Here, we introduce midgap states and nanoscale precipitates using Ga-doping and GeTe-alloying to considerably improve the performance of n-type PbTe. The GeTe alloying significantly enlarges the energy band gap of PbTe and subsequent Ga doping introduces special midgap states that lead to an increased density of states (DOS) effective mass and enhanced Seebeck coefficients. Moreover, the nucleated Ga2Te3 nanoscale precipitates and off-center discordant Ge atoms in the PbTe matrix cause intense phonon scattering, strongly reducing the thermal conductivity (∼0.65 W m-1 K-1 at 623 K). As a result, a high room-temperature thermoelectric figure of merit ZT ∼0.59 and a peak ZTmax of ∼1.47 at 673 K were obtained for the Pb0.98Ga0.02Te-5%GeTe. The ZTavg value that is most relevant for devices is ∼1.27 from 400 to 773 K, the highest recorded value for n-type PbTe.

AB - PbTe-based thermoelectric materials are some of the most promising for converting heat into electricity, but their n-type versions still lag in performance the p-type ones. Here, we introduce midgap states and nanoscale precipitates using Ga-doping and GeTe-alloying to considerably improve the performance of n-type PbTe. The GeTe alloying significantly enlarges the energy band gap of PbTe and subsequent Ga doping introduces special midgap states that lead to an increased density of states (DOS) effective mass and enhanced Seebeck coefficients. Moreover, the nucleated Ga2Te3 nanoscale precipitates and off-center discordant Ge atoms in the PbTe matrix cause intense phonon scattering, strongly reducing the thermal conductivity (∼0.65 W m-1 K-1 at 623 K). As a result, a high room-temperature thermoelectric figure of merit ZT ∼0.59 and a peak ZTmax of ∼1.47 at 673 K were obtained for the Pb0.98Ga0.02Te-5%GeTe. The ZTavg value that is most relevant for devices is ∼1.27 from 400 to 773 K, the highest recorded value for n-type PbTe.

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U2 - 10.1021/jacs.9b09249

DO - 10.1021/jacs.9b09249

M3 - مقالة

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JO - Journal of the American Chemical Society

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ER -

High Figure of Merit in Gallium-Doped Nanostructured n-Type PbTe- xGeTe with Midgap States

Abstract

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