Synthesis of SnTe/AgSbSe 2 nanocomposite as a promising lead-free thermoelectric material

A series of SnTe-AgSbSe2 composites were synthesized by a zone-melting method. The nanostructure of the composites was determined by the high resolution transmission electron microscope. The results show that the lattice thermal conductivity is decreased to ∼0.6 W/m·K at 820 K due to the intense scattering of phonon. Also, the carrier concentration increases with AgSbSe2 amounts, and a large effective mass of ∼ 4m0 at room temperature appears at a high carrier concentration of ∼2 × 1021/cm3. A relatively high thermoelectric figure of merit ZT of 0.92 at 820 K is obtained by composition optimization. It is indicated that the SnTe-AgSbSe2 composite should be a promising thermoelectric material.