Strong Phonon Scattering by Layer Structured PbSnS2 in PbTe Based Thermoelectric Materials



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The incorporation of PbSnS2 in PbTe results in a tremendous reduction of the lattice thermal conductivity to 0.8 W/mK at room temperature, a reduction of almost 60% over bulk PbTe. Transmission electron microscopy reveals very high density displacement layers, misfit dislocations, and phase boundaries. Our thermal transport calculations based on modified Debye-Callaway model, well in agreement with the experimental measurements, reveal that the layer structured PbSnS2 plays an important role in reducing the lattice thermal conductivity.