Enhancing the solubility of Mn in AgSbSe2 for high thermoelectric performance through entropy engineering

Point defects play an important role in regulating the electrical and thermal transport properties of thermoelectric materials, but it is always restricted by the solubility of dopants in the matrix. Herein, we demonstrate an effective route to enhance the solubility of Mn from 8% up to 30% in AgSbSe2 through entropy-driven alloying with MnSe. It enables us to largely enhance the carrier concentration and electrical conductivity and also reduce the lattice thermal conductivity of AgSbSe2. As a consequence, (AgSbSe2)(0.7)(MnSe)(0.3) has a high ZT of similar to 0.96 at 750 K. Moreover, a further enhanced ZT of 1.18 was achieved in (AgSbSe2)(0.7)(Mn0.99Se)(0.3) at 750 K by the introduced Mn vacancies.

Automated summary

Point defects play an important role in regulating the electrical and thermal transport properties of thermoelectric materials. In this study, the solubility of Mn in AgSbSe2 was effectively enhanced through entropy-driven alloying with MnSe. This led to significant improvement in carrier concentration, electrical conductivity, and reduction in lattice thermal conductivity of AgSbSe2, resulting in high ZT values of 0.96 at 750 K for (AgSbSe2)(0.7)(MnSe)(0.3) and further enhanced value of 1.18 at 750 K for (AgSbSe2)(0.7)(Mn0.99Se)(0.3) due to introduced Mn vacancies.