| Abstract Scope |
Mg₃Sb₂-based thermoelectric (TE) materials have attracted great attention for low- to mid-temperature TE applications. This talk will present our efforts in tuning carrier concentrations using various dopants, such as Y and Mn for the Mg site and Bi for the Sb site. Both Y and Mn doping can suppress Mg vacancies and lead to a peak ZT of ~1.8 at 773 K. Bi doping reduces the band gap, and a peak ZT of 1.74 at 573 K is achieved in Mg₃.₁₉Mn₀.₀₁Sb₀.₉₉BiTe₀.₀₁. We also show that impurity phases, such as Mn₃Bi₂, Mn₂Sb, and MnSb, can form with excessive Mn doping. These secondary phases behave like electron-trapping centers and convert the n-type behavior to p-type. |