Enhanced thermoelectric performance in In1-xGaxSb originating from the scattering of point defects and nanoinclusion

InSb-based semiconductors have not been regarded as a promising thermoelectric candidates before due to their high thermal conductivity. In this paper, Ga substitution and nanoinclusions poor in Ga were introduced to serve as phonon scattering centres. The nanoinclusions, possessing a heterogeneous isomorphic crystal structure with the matrix, contribute to the weakly influenced electrical transport and greatly depressed lattice thermal conductivity (kappa(L)). For the sample In0.9Ga0.1Sb, the kappa(L) is decreased by 53% and the ZT value is increased by 62% compared with pure InSb at 650 K. The highest ZT achieved was 0.73, which shows application perspectives at intermediate temperatures.