Microstructures and thermoelectric properties of p-type pseudo-binary Bi–Sb–Te alloys with partial substitution of Ga for Sb prepared by spark plasma sintering

P-type pseudo-binary Bi–Sb–Te alloys with Ga substitution for Sb in raw mixtures were prepared by spark plasma sintering (SPS) technique, results show that a proper Ga substitution for Sb can improve the thermoelectric performance near room temperature. With molar fraction x increasing from 0 to 0.1 in the GaxBi0.5Sb1.5−xTe3 alloys, a ratio σ/κ can be enhanced from 23,178 to 34,807 K V−2 at 318 K, without noticeable loss of Seebeck coefficients. The maximum ZT value of 0.65 (±0.16) is achieved, being approximate 0.11 higher than that of Bi0.5Sb1.5Te3.