Carrier and Phonon Engineering in Sb‐Doped Sn 0.8 Mn 0.1 Pb 0.1 Te: A Pathway to Superior Thermoelectric Performance

ABSTRACT SnTe is considered a potential alternative to PbTe for thermoelectric applications. However, excessive carrier concentration and thermal conductivity result in poor thermoelectric performance. Herein, p‐type SnTe‐based materials Sn 0.8‐ x Mn 0.1 Pb 0.1 Sb x Te were synthesized, and the combined effects of Sb, Mn, and Pb were systematically investigated. Mn doping promotes band convergence, leading to a high Seebeck coefficient, whereas Pb doping enhances power factor and simultaneously reduces the total thermal conductivity. The doping of the Sb element reasonably regulates the carrier concentration, leading to an increase in the Seebeck coefficient and resulting in a sample with excellent electrical transport performance. Additionally, Sb incorporation induces the formation of point defects, edge dislocations, grain boundaries, and nanoprecipitates within the SnTe matrix, which significantly lowers the lattice thermal conductivity. The lattice thermal conductivity of the Sn 0.71 Mn 0.1 Pb 0.1 Sb 0.09 Te alloy decreases to 1.06 W m −1 K −1 at 323 K. The increase in resistivity leads to a decrease in electronic thermal conductivity, resulting in an extremely low total thermal conductivity of the sample. Therefore, a ZT value of ∼1.27 at 773 K is recorded for the Sn 0.71 Mn 0.1 Pb 0.1 Sb 0.09 Te sample, which represents a 272% improvement over intrinsic SnTe. The remarkable enhancement unequivocally confirms that the optimized doping strategy effectively improves the alloy's thermoelectric performance.