Enhancement of Seebeck Coefficient in Bi0.5Sb1.5Te₃ with High-Density Tellurium Nanoinclusions

Bi 0.5 Sb 1.5 Te 3 films with homogeneously dispersed ∼15 nm Te nanoparticles were prepared by the alternate deposition of Bi 0.5 Sb 1.5 Te 3 layers and Te nanoparticles. As the amount of Te nanoinclusions increased to 15 vol %, the Seebeck coefficient increased from 169 to 248 µV/K. The authors concluded that the high-density Te nanoinclusions result in a carrier energy filtering effect in Bi 0.5 Sb 1.5 Te 3 . Consequently, the thermoelectric power factor was enhanced by 30% despite a reduction in electrical conductivity. The improvement of the power factor implies the enhancement of the thermoelectric figure of merit ZT , providing the possibility of further ZT improvement by embedding Te nanoinclusions in Bi 0.5 Sb 1.5 Te 3 bulk materials.