Discovery of high-performance low-cost n-type Mg3Sb2-based thermoelectric materials with multi-valley conduction bands
نویسندگان
چکیده
Widespread application of thermoelectric devices for waste heat recovery requires low-cost high-performance materials. The currently available n-type thermoelectric materials are limited either by their low efficiencies or by being based on expensive, scarce or toxic elements. Here we report a low-cost n-type material, Te-doped Mg3Sb1.5Bi0.5, that exhibits a very high figure of merit zT ranging from 0.56 to 1.65 at 300-725 K. Using combined theoretical prediction and experimental validation, we show that the high thermoelectric performance originates from the significantly enhanced power factor because of the multi-valley band behaviour dominated by a unique near-edge conduction band with a sixfold valley degeneracy. This makes Te-doped Mg3Sb1.5Bi0.5 a promising candidate for the low- and intermediate-temperature thermoelectric applications.
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*Contributed equally to this work a Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA Correspondence and requests for materials should be addressed to G. Jeffrey Snyder (E-mail: [email protected]) b Department of Applied Physics and Materials Science, California Institute of Technology, Pasadena, California 91125, USA c Division o...
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عنوان ژورنال:
دوره 8 شماره
صفحات -
تاریخ انتشار 2017