Enhanced thermoelectric performance of CuSbSe2 via Mn doping

Ternary chalcostibite CuSbSe2 compound is known for low thermal conductivity. However, the poor electrical properties severely limit its thermoelectric performance. In this study, the Mn-doped CuSb1-xMnxSe2 (x = 0-0.04) samples were synthesized by vacuum melting with spark plasma sintering, and their thermoelectric properties were characterized. The results indicate that the impurity phase Cu3SbSe3 will be generated when Mn content x > 0.02, and the carrier concentration and mobility were optimized significantly for the Mn-doped compounds, thus enhancing the electrical transport performance. In terms of results, the PF increases from 1.3 x 10(2) to 2.18 x 10(2) mu W m(-1) K-2 at 673 K. Point defects and the second phase enhance phonon scattering and lead to a lower lattice thermal conductivity for CuSb1-xMnxSe2 compounds, the kappa(l) decreases from 0.39 to 0.26 W m(-1) K-1 at 673 K. As a consequence, a maximum figure of merit ZT of similar to 0.53 was achieved at 673 K for CuSb0.97Mn0.03Se2, which is 140 % higher than the intrinsic CuSbSe2.

Automated summary

In this study, Mn-doped CuSb1-xMnxSe2 samples were synthesized and their thermoelectric properties were characterized. The results showed that Mn doping significantly optimized the carrier concentration and mobility, enhancing the electrical transport performance. Additionally, the lattice thermal conductivity of the compounds decreased, resulting in a higher figure of merit ZT.