Thermoelectric performance of Mg2.2(Ge0.9Sn0.1) ternary solid solution doped with Ag, Bi, Ni and Sb

Mg2.2(Ge0.9Sn0.1)0.94X0.06(X = Ag, Bi, Ni, Sb) ternary solid solutions were synthesized using a two-step solid state reaction followed by hot pressing. The effects elemental doping on thermoelectric properties of these compounds were studied in the temperature range of 300 to 800 K. The findings demonstrate that Bi, Sb, and Ni function as useful n-type dopants, with Bi being more efficiently in the solid solution of Mg2.2Ge0.9Sn0.1. Additionally, the findings indicate that Ag is less efficient in n-type doping. Finally, maximum ZT for the Bi-doped sample is 0.82 at 800 K because of its strong electrical conductivity and moderate Seebeck coefficient.