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

Jared B. Williams, Donald T. Morelli

Research output: Contribution to journalArticle

  • 1 Citations

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.

LanguageEnglish (US)
Pages1-10
Number of pages10
JournalJournal of Electronic Materials
DOIs
StateAccepted/In press - Aug 18 2016

Profile

figure of merit
thermoelectric materials
Seebeck effect
thermal conductivity
Seebeck coefficient
waste heat
electrical resistivity
commercialization
Thermal conductivity
operating temperature
unity
Phase change memory
recovery
engineering
Poisons
solid state
cooling
Waste heat utilization
Conversion efficiency
scattering

Keywords

  • composite
  • phase-change material
  • Thermoelectric

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry

Cite this

Using Ge Secondary Phases to Enhance the Power Factor and Figure of Merit of Ge17Sb2Te20 . / Williams, Jared B.; Morelli, Donald T.

In: Journal of Electronic Materials, 18.08.2016, p. 1-10.

Research output: Contribution to journalArticle

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