Enhanced thermoelectric performance of Bi0.4Sb1.6Te3 based composites with CuInTe2 inclusions

Bi0.4Sb1.6Te3 (BST) based composites incorporated with CuInTe2 particles have been prepared and their thermoelectric properties were studied in the temperature range from 300 to 500 K. The results indicate that at 300 K the incorporation of 0.2 wt% CuInTe2 in BST causes 14% increase in power factor (PF) and 38% reduction in lattice conductivity simultaneously. As a result, a maximum ZT = 1.45 at 400 K is achieved in the composite sample with f = 0.2 wt%, which is ∼45% larger than that of BST studied here. The enhancement of PF originates from the increase of both electrical conductivity due to increased hole concentration and thermopower via energy filtering effect. While, the reduction of the lattice thermal conductivity could be ascribed to enhanced phonon scattering at the interfaces and CuInTe2 inclusions in the composite samples. Present results demonstrate that incorporation of a proper amount of CuInTe2 in BST is an effective way to improving thermoelectric performance of BST alloys.