Authors: Jared B Williams Donald T Morelli
Publish Date: 2016/08/18
Volume: 46, Issue: 5, Pages: 2652-2661
Abstract
Thermoelectric materials are the leading candidate today for applications in solidstate wasteheat 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 stateoftheart 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 phasechange memory because of their ability to rapidly alternate between crystalline and amorphous phases Recently these materials have been identified as materials with ZT S 2 T/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 2This work was supported at Michigan State University as part of the Center for Revolutionary Materials for Solid State Energy Conversion an Energy Frontier Research Center funded by the US Department of Energy Office of Science Office of Basic Energy Sciences under Award Number DESC0001054 The authors would like to acknowledge Karl Dersch of the Electrical Engineering department for assistance in hightemperature laser flash The authors would also like to acknowledge Spencer Waldrop and Winston Carr for their knowledgeable advice and insightful discussions pertaining to this project
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