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

Bi(0.5)Sb(1.5)Te(3) compounds were prepared by cold-press and thermal/electrical sintering process. A high-density electric current (similar to 100 A/cm(2)) was introduced through the cold-pressed Bi(0.5)Sb(1.5)Te(3) samples during pressure-free sintering at a temperature similar to 200 degrees C. The electrically sintered Bi(0.5)Sb(1.5)Te(3) 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 Bi(0.5)Sb(1.5)Te(3) 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 Bi(0.5)Sb(1.5)Te(3). (C) 2009 Elsevier B.V. All rights reserved.