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Title: Using Ge Secondary Phases to Enhance the Power Factor and Figure of Merit of Ge17Sb2Te20

Abstract

Thermoelectric materials are the leading candidate today for applications in solid-state waste-heat recovery/cooling applications. Research and engineering has pushed the ZT, and overall conversion efficiency, of these materials to values which can be deemed practical for commercialization. However, many of the state-of-the-art thermoelectric materials of today utilize elements which are toxic, such as Ag, Pb, Tl, and Cd. Alloys of GeTe and Sb2Te3 were first explored for their applications in phase-change memory, because of their ability to rapidly alternate between crystalline and amorphous phases. Recently, these materials have been identified as materials with ZT (S2T/ρκ, where S is the Seebeck coefficient, ρ is the electrical resistivity, T is the operating temperature, and κ is the thermal conductivity) much greater than unity. In this work, the influence of elemental Ge as a secondary phase on transport in Ge17Sb2Te20 was explored. It was found that Ge introduces an additional scattering mechanism, which leads to increased electrical resistivity, Seebeck coefficient, and power factor values as high as 36 μW cm-1 K-2. The thermal conductivity was slightly reduced and the ZT was enhanced across the entire temperature range of measurement, with peak values greater than 2.

Authors:
;
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC) (United States). Revolutionary Materials for Solid State Energy Conversion (RMSSEC)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1397220
DOE Contract Number:
SC0001054
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Electronic Materials; Journal Volume: 46; Journal Issue: 5; Related Information: RMSSEC partners with Michigan State University (lead); University of California, Los Angeles; University of Michigan; Northwestern University; Oak Ridge National Laboratory; Ohio State University; Wayne State University
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Williams, Jared B., and Morelli, Donald T. Using Ge Secondary Phases to Enhance the Power Factor and Figure of Merit of Ge17Sb2Te20. United States: N. p., 2016. Web. doi:10.1007/s11664-016-4858-x.
Williams, Jared B., & Morelli, Donald T. Using Ge Secondary Phases to Enhance the Power Factor and Figure of Merit of Ge17Sb2Te20. United States. doi:10.1007/s11664-016-4858-x.
Williams, Jared B., and Morelli, Donald T. 2016. "Using Ge Secondary Phases to Enhance the Power Factor and Figure of Merit of Ge17Sb2Te20". United States. doi:10.1007/s11664-016-4858-x.
@article{osti_1397220,
title = {Using Ge Secondary Phases to Enhance the Power Factor and Figure of Merit of Ge17Sb2Te20},
author = {Williams, Jared B. and Morelli, Donald T.},
abstractNote = {Thermoelectric materials are the leading candidate today for applications in solid-state waste-heat recovery/cooling applications. Research and engineering has pushed the ZT, and overall conversion efficiency, of these materials to values which can be deemed practical for commercialization. However, many of the state-of-the-art thermoelectric materials of today utilize elements which are toxic, such as Ag, Pb, Tl, and Cd. Alloys of GeTe and Sb2Te3 were first explored for their applications in phase-change memory, because of their ability to rapidly alternate between crystalline and amorphous phases. Recently, these materials have been identified as materials with ZT (S2T/ρκ, where S is the Seebeck coefficient, ρ is the electrical resistivity, T is the operating temperature, and κ is the thermal conductivity) much greater than unity. In this work, the influence of elemental Ge as a secondary phase on transport in Ge17Sb2Te20 was explored. It was found that Ge introduces an additional scattering mechanism, which leads to increased electrical resistivity, Seebeck coefficient, and power factor values as high as 36 μW cm-1 K-2. The thermal conductivity was slightly reduced and the ZT was enhanced across the entire temperature range of measurement, with peak values greater than 2.},
doi = {10.1007/s11664-016-4858-x},
journal = {Journal of Electronic Materials},
number = 5,
volume = 46,
place = {United States},
year = 2016,
month = 8
}
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