[17p-Z17-1~19] 9.4 Thermoelectric conversion

[17p-Z17-11] Enhancement of Thermoelectric Performance of Mg₂Sn Single Crystal via Sb and B co-substitution

〇Wataru Saito¹, Kei Hayashi¹, Zhicheng Huang¹, Yuzuru Miyazaki¹ (1.Tohoku Univ.)

Keywords:Thermoelectric, Mg2Sn, point defect engineering

To enhance a thermoelectric (TE) performance of Mg₂Sn single-crystal (SC), M-doped Mg₂Sn SC ingots (M = Sb + B) were fabricated. All of the ingots contained Mg vacancy (V_Mg) as a point defect, and a fraction of the V_Mg increased with decreasing a lattice constant. Regarding the TE performance, the B doping significantly reduces a lattice thermal conductivity and slightly reduces a power factor. Reflecting the reduction of the lattice thermal conductivity, a maximum dimensionless figure of merit (zT_max) of 0.83 was realised for the Sb + B doped ingot, which is higher than that of Sb doped Mg₂Sn SC ingot.