Thermoelectric properties of Bi–Sb–Te materials prepared by electric current stressing

Bi0.5Sb1.5Te3 compounds were prepared by cold-press and thermal/electrical sintering process. A high-density electric current (∼100 A/cm2) was introduced through the cold-pressed Bi0.5Sb1.5Te3 samples during pressure-free sintering at a temperature ∼200 °C. The electrically sintered Bi0.5Sb1.5Te3 shows a 6-fold increase in carrier mobility and 60% reduction in carrier density as compared to the thermally sintered sample. The change in carrier transport properties is suggested to be associated with the elimination of charged defects in Bi0.5Sb1.5Te3 crystal during electric current stressing. An electric current induced defect restoration mechanism is proposed to explain the enhanced carrier transport property of the electrically sintered Bi0.5Sb1.5Te3.