Date/Time: 04-04-2018 - Wednesday - 05:00 PM - 07:00 PM
Kazuki Imasato1 Stephen Kang2 1 Saneyuki Ohno2 1 G. Snyder1

1, Northwestern University, Evanston, Illinois, United States
2, California Institute of Technology, Pasadena, California, United States

The strategy of alloying in the Mg3Sb2-Mg3Bi2 thermoelectric compound has originally been understood mostly as a means to reducing the thermal conductivity. However, it is evident from electronic transport properties that alloying also has a significant impact on the band structure. To fully understand the optimum alloy composition for thermoelectrics, it is necessary to model both the p- and n-type compounds as a function of the Mg3Sb2 vs. Mg3Bi2 composition. We establish a model for the optimum alloy composition and find that the electronic property enhancement accounts for about 50 % of the benefits from alloying. We discuss how the Mg3Sb2-Mg3Bi2 alloying impacts the band structure in terms of the band gap, mass, and convergence, which are the essential features that should be considered for band engineering in this material.

Meeting Program

5:00 PM–7:00 PM Apr 4, 2018 (America - Denver)

PCC North, 300 Level, Exhibit Hall C-E