2025/11/11 by Jiankang Li, Raju Chetty, Zihang Liu +2
Materials Science · Physics and Astronomy · #Advanced Thermoelectric Materials and Devices #Heusler alloys: electronic and magnetic properties #Topological Materials and Phenomena
paper · doi:10.48505/nims.5887
N-type Mg3Sb2 alloys show great potential for wasted heat energy harvesting due to their promising thermoelectric properties. In this work, we discover that doping transition element Ag into the n-type Mg3Sb2 alloy can effectively optimize the power factor and suppress the lattice thermal conductivity simultaneously. A high power factor of 19.6 μW cm−1 K−2 is obtained at 673 K owing to the increased electrical conductivity. At the same time, the lattice thermal conductivity is reduced to 0.50 W m-1 K-1 as a result of enhanced phonon scattering induced Ag atoms. These improvements lead to a peak figure of merit (ZT) of 1.64 at 673 K as well as a high average ZT of 1.27 is obtained from 323K to 673K. Furthermore, a thermoelectric single leg device with a competitive conversion efficiency of ~11% under a hot-side temperature of 673 K is fabricated successfully, suggesting an exceptional potential in the future application for in waste heat energy harvesting and thermoelectric power generation.