Wide‐Temperature‐Range SnTe Thermoelectrics with High Average Figure of Merit

Abstract Here, an extraordinary average ZT of 1.18 and a high peak ZT of 1.5 in Sn _0.87‐y‐z Al _0.08 Sb _y Mn _0.08 Ag _z Te compounds are reported. By increasing the configurational entropy, the band structure has been optimized markedly. The energy offset is significantly reduced, and a resonant level adjacent to the Fermi level is produced through increasing the configurational entropy, which contributes to a largely enhanced power factor over a broad temperature range. More importantly, the disorder and point defect scattering in Sn _{1.03‐x‐y‐z} Al _x Sb _y Mn _x Ag _z Te material are greatly increased caused by increasing the configurational entropy. Ultimately, the introduction of a highly disordered microstructure, which includes dense dislocations, precipitates, disorder, and point defects provide multi‐scale phonon scattering centers, thus the lattice thermal conductivity is significantly suppressed. The lowest lattice thermal conductivity is reduced as low as 0.30 Wm ⁻¹ K ⁻¹ . The proposed strategy of entropy engineering has achieved remarkable success in enhancing the average thermoelectric performance of SnTe‐based material over a wide temperature range and holds significant promise for application to other material systems.