Enhancing thermoelectric properties of p-type SiGe by SiMo addition

The thermoelectric properties of SiGe– x %SiMo composites are studied from 323 to 1173 K. Electrical conductivity increases with SiMo concentration due to improved carrier mobility and reaches a peak of 1735 S cm −1 when x  = 20. The sample SiGe–20%SiMo shows the highest PF of 2.9 mW −1  m −1  K −2 at 1073 K, which is 31.8% higher than the PF value of SiGe. Although total thermal conductivities increase after SiMo addition, the lattice thermal conductivities are reduced due to strengthened phonon scattering by the presence of MoSi 2 . The ZT of SiGe is 0.64 at 1073 K. It is increased for all the composites in the high-temperature range between 773 and 1073 K, which is beneficial to high temperature application of SiGe alloys. SiGe–20%SiMo shows the highest ZT of 0.79 at 1073 K.