Ultrafast Synthesis of SnTe Thermoelectric Materials with Intrinsic Constituent Fluctuation

Traditional methods for preparing SnTe thermoelectric materials, such as melting and powder metallurgy, are time- and energy consuming, limiting their large-scale industrial applications. In this study, high-quality SnTe compounds were prepared using levitation melting combined with spark plasma sintering, reducing the synthesis time from several days to a few minutes. The as-sintered SnTe samples exhibited large intrinsic compositional fluctuation, resulting in a thermoelectric figure of merit (ZT) value of up to 0.6 at 873 K, comparable to the best-reported results for undoped SnTe compounds. Further, the Sn vacancies were unstable in SnTe, especially when their content exceeded 0.03, and should be avoided in the matrix. Subsequently, by Sb substitution, the ZT value of the Sn0.85Sb0.15Te sample increased to 1.13 at 873 K, showing good modulation compared to that of a sample prepared by traditional methods. The widespread application of this method would aid commercialization and broaden prospects for the environmentally friendly mass production of SnTe-based thermoelectric materials.