Low temperature thermoelectric properties and aging phenomena of nanostructured p-type Bi2-XSbXTe3 (x = 1.46, 1.48, 1.52 and 1.55)

Dale Hitchcock, Yen Liang Liu, Yufei Liu, Terry M. Tritt, Jian He, Chia-Jyi Liu

Research output: Contribution to journalArticle

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Abstract

Over the past decade the widely used p-type (Bi2-xSb x)Te3 bulk thermoelectric materials have been subject to various nanostructuring processes for higher thermoelectric performance. However, these nanostructuring processing were conducted on compositions optimized for bulk materials (x ∼ 1.52-1.55). This leads to the question of whether the optimal composition for bulk materials is the same for their nanoscale counterparts. In this work we hydrothermally grew Bi 2-xSbxTe3 nanopowders (nominally, x = 1.46, 1.48, 1.52 and 1.55) and measured their thermoelectric properties on cold-pressed vacuum-sintered pellets (74-78% of the theoretical density) below 300 K. The measurements were conducted 18 months apart to probe the aging phenomena, with the samples stored in ambient conditions. We have found that (i) the peak of thermopower shifts to lower temperatures upon nanostructuring but it shifts back to higher temperatures upon aging; (ii) the electrical conductivity degrades by a factor of 1.5-2.3 upon aging while the temperature dependence is largely retained; and (iii) the ZT of freshly made samples is sensitive to the x value, a maximum ZT ∼ 1.25(∼ 0.62) at ∼ 270 K (∼ 255 K) was attained in the freshly made sample x = 1.55(x = 1.46), respectively; while the ZT of aged samples is significantly lowered by a factor of 2-4 but lesser x-dependent. These observations have been discussed in the context of charge buildup and compensation at grain boundaries.

Original languageEnglish
Article number1340008
JournalFunctional Materials Letters
Volume6
Issue number5
DOIs
Publication statusPublished - 2013 Oct 1

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Aging of materials
Thermoelectric power
Chemical analysis
Temperature
Grain boundaries
Vacuum
Processing
Electric Conductivity
Compensation and Redress

All Science Journal Classification (ASJC) codes

  • Materials Science(all)

Cite this

@article{74d3d52dee364523a04d26c178b422af,
title = "Low temperature thermoelectric properties and aging phenomena of nanostructured p-type Bi2-XSbXTe3 (x = 1.46, 1.48, 1.52 and 1.55)",
abstract = "Over the past decade the widely used p-type (Bi2-xSb x)Te3 bulk thermoelectric materials have been subject to various nanostructuring processes for higher thermoelectric performance. However, these nanostructuring processing were conducted on compositions optimized for bulk materials (x ∼ 1.52-1.55). This leads to the question of whether the optimal composition for bulk materials is the same for their nanoscale counterparts. In this work we hydrothermally grew Bi 2-xSbxTe3 nanopowders (nominally, x = 1.46, 1.48, 1.52 and 1.55) and measured their thermoelectric properties on cold-pressed vacuum-sintered pellets (74-78{\%} of the theoretical density) below 300 K. The measurements were conducted 18 months apart to probe the aging phenomena, with the samples stored in ambient conditions. We have found that (i) the peak of thermopower shifts to lower temperatures upon nanostructuring but it shifts back to higher temperatures upon aging; (ii) the electrical conductivity degrades by a factor of 1.5-2.3 upon aging while the temperature dependence is largely retained; and (iii) the ZT of freshly made samples is sensitive to the x value, a maximum ZT ∼ 1.25(∼ 0.62) at ∼ 270 K (∼ 255 K) was attained in the freshly made sample x = 1.55(x = 1.46), respectively; while the ZT of aged samples is significantly lowered by a factor of 2-4 but lesser x-dependent. These observations have been discussed in the context of charge buildup and compensation at grain boundaries.",
author = "Dale Hitchcock and Liu, {Yen Liang} and Yufei Liu and Tritt, {Terry M.} and Jian He and Chia-Jyi Liu",
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Low temperature thermoelectric properties and aging phenomena of nanostructured p-type Bi2-XSbXTe3 (x = 1.46, 1.48, 1.52 and 1.55). / Hitchcock, Dale; Liu, Yen Liang; Liu, Yufei; Tritt, Terry M.; He, Jian; Liu, Chia-Jyi.

In: Functional Materials Letters, Vol. 6, No. 5, 1340008, 01.10.2013.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Low temperature thermoelectric properties and aging phenomena of nanostructured p-type Bi2-XSbXTe3 (x = 1.46, 1.48, 1.52 and 1.55)

AU - Hitchcock, Dale

AU - Liu, Yen Liang

AU - Liu, Yufei

AU - Tritt, Terry M.

AU - He, Jian

AU - Liu, Chia-Jyi

PY - 2013/10/1

Y1 - 2013/10/1

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