Power factor improvement in hydrothermally synthesized Bi2−xSbxTe3 (x=1.5) — carbon sphere composites

We report fabrication of compacted Bi0.5Sb1.5Te3 composites by adding 1 wt% of carbon spheres in the hydrothermal synthesis. The processing parameter of sintering temperature is investigated in order to optimize the thermoelectric power factor of pressed Bi0.5Sb1.5Te3 composites. As a result, we find that the composite sintered at 360 °C shows the best power factor performance among the composites and has a largest power factor of 15.4 μW/cm K2 at 205 K and 13.5 μW/cm K2 at 290 K. When compared with the samples without addition of carbon sphere in the hydrothermal synthesis, the composites sintered at 340 °C and 360 °C both surpass the largest power factor of 12.1 μW/cm K2 at 280 K and 11.9 μW/cm K2 at 290 K for the 340 °C-sintered counterpart.