Authors: Hsin Wang Wallace D Porter Harald Böttner Jan König Lidong Chen Shengqiang Bai Terry M Tritt Alex Mayolet Jayantha Senawiratne Charlene Smith Fred Harris Patricia Gilbert Jeff Sharp Jason Lo Holger Kleinke Laszlo Kiss
Publish Date: 2013/03/13
Volume: 42, Issue: 6, Pages: 1073-1084
Abstract
For bulk thermoelectrics improvement of the figure of merit ZT to above 2 from the current values of 10 to 15 would enhance their competitiveness with alternative technologies In recent years the most significant improvements in ZT have mainly been due to successful reduction of thermal conductivity However thermal conductivity is difficult to measure directly at high temperatures Combined measurements of thermal diffusivity specific heat and mass density are a widely used alternative to direct measurement of thermal conductivity In this work thermal conductivity is shown to be the factor in the calculation of ZT with the greatest measurement uncertainty The International Energy Agency IEA group under the implementing agreement for Advanced Materials for Transportation AMT has conducted two international roundrobins since 2009 This paper part II of our report on the international roundrobin testing of transport properties of bulk bismuth telluride focuses on thermal diffusivity specific heat and thermal conductivity measurementsThe authors would like to thank the International Energy Agency under the Implementing Agreement for Advanced Materials for Transportation for supporting this work and the assistant secretary for Energy Efficiency and Renewable Energy of the Department of Energy and the Propulsion Materials Program under the Vehicle Technologies Program We would like to acknowledge support from all participating institutions and Oak Ridge National Laboratory managed by UTBattelle LLC under contract DEAC05000OR22725
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