Affiliation:
1. School of Physics, State Key Laboratory of Crystal Materials Shandong University Jinan 250100 P. R. China
Abstract
AbstractSnTe, as a potential medium‐temperature thermoelectric material, reaches a maximum power factor (PF) usually above 750 K, which is not conducive to continuous high‐power output in practical applications. In this study, PF is maintained at high values between 18.5 and 25 µW cm−1 K−2 for Sn0.99In0.01Te−x wt% tourmaline samples within the temperature range of 323 to 873 K, driving the highest PFeng of 1.2 W m−1 K−1 and PFave of 22.5 µW cm−1 K−2, over 2.5 times that of pristine SnTe. Such an extraordinary PF is attributed to the synergy of resonant levels and Sn vacancy suppression. Specifically, the Seebeck coefficient increases dramatically, reaching 88 µV K−1 at room temperature. Meanwhile, by Sn vacancy suppression, carrier concentration, and mobility are optimized to ≈1019 cm−3 and 740 cm2 V−1 s−1, respectively. With the tourmaline compositing, Sn vacancies are further suppressed and the thermal conductivity simultaneously decreases, with the minimum lattice thermal conductivity of 0.9 W m−1 K−1. Finally, the zT value ≈0.8 is obtained in the Sn0.99In0.01Te sample. The peak of the power output density reaches 0.89 W cm−2 at a temperature difference of 600 K. Such SnTe alloys with high and “temperature‐independent” PF will offer an option for realizing high output power in thermoelectric devices.
Funder
National Key Research and Development Program of China
China Postdoctoral Science Foundation
Natural Science Foundation of Shandong Province