In Situ Reaction Induced Core-Shell Structure to Ultralow ?_lat and High Thermoelectric Performance of SnTe.

ABSTRACT: Lead-free chalcogenide SnTe has been demonstrated to be an efficient medium temperature thermoelectric (TE) material. However, high intrinsic Sn vacancies as well as high thermal conductivity devalue its performance. Here, ?-Zn₄Sb₃ is incorporated into the SnTe matrix to regulate the thermoelectric performance of SnTe. Sequential in situ reactions take place between the ?-Zn₄Sb₃ additive and SnTe matrix, and an interesting "core-shell" microstructure (Sb@ZnTe) is obtained; the composition of SnTe matrix is also tuned and thus Sn vacancies are compensated effectively. Benefitting from the synergistic effect of the in situ reactions, an ultralow ?_lat ?0.48 W m^-1 K^-1 at 873 K is obtained and the carrier concentrations and electrical properties are also improved successfully. Finally, a maximum ZT ?1.32, which increases by ?220% over the pristine SnTe, is achieved in the SnTe-1.5% ?-Zn₄Sb₃ sample at 873 K. This work provides a new strategy to regulate the TE performance of SnTe and also offers a new insight to other related thermoelectric materials.

SUBMITTER: Li S 

PROVIDER: S-EPMC7284213 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature