Achieving High Thermoelectric Performance of SnTe Composites with 2D WSe

In this work, we introduced two-dimensional (2D) WSe with the lowest heat conductivity to enhance thermoelectric properties of the non-toxic and cost-effective SnTe. On one hand, the improved power factor can be attributed to the enhancement of Seebeck coefficient due to the decrease of low-energy carriers and minority carriers by the addition of WSe-SnTe p-p-type heterojunction interface barriers. On the other hand, the thermal conductivity also decreased sharply by the heightened phonon scattering from the high-density stacking faults and multiscale hierarchical architectures. Ultimately, benefiting from the dual regulation effect of the introduction of 2D WSe on the electro-acoustic decoupling, an improved figure of merit (ZT) of 1.0 is achieved for the composition of SnTe + 6 wt% WSe at 873 K, which is enhanced by 134% in comparison with the pure SnTe sample. Moreover, the meaningful attempt represents an effective and feasible strategy for mixing SnTe with other compounds by the method of ball milling. Graphical Abstract: [Figure not available: see fulltext.].