Thermoelectric properties of Sb-doped Mg2Si by solid state reaction

In the present paper, Sb-doped Mg₂Si thermoelectric materials were successfully prepared by solid state reaction. Effects of doped Sb on the structure and thermoelectric properties of the Mg₂Si compounds were mainly investigated. The results show that the power factor of Mg₂Si increases to 3.3 × 10^-3W/mK² at about 650K when doped with 0.5wt%Sb, much higher than the pure Mg₂Si or Mg₂Si-based compounds fabricated by the traditional fusion method and SPS method. It is also found that the forbidden energy gap of the system is reduced because the doped Sb introduces lots of defects and thus it is easier for the electrons to transit. As a result, the Seebeck coefficient and electrical conductivity of Sb-doped Mg₂Si compounds are increased considerably.