Thermoelectric transport properties of bismuth telluride bulk materials fabricated by ball milling and spark plasma sintering

Dense bismuth telluride (Bi2Te3) bulk materials with randomly packed grains were prepared using attrition milling and spark plasma sintering (SPS). Experimental results indicate that the high energy ball milling produces donor-like carriers in Bi2Te3 samples and enhances thermoelectric transport properties such as carrier concentration, electrical conductivity and power factor. The maximum power factor of 1 mW m(-1) K-2 was obtained at 500 K for the 3 h-milled Bi2Te3 sample sintered at 573 K. Results of this study demonstrate that adequately controlling the milling time can enhance the thermoelectric performance of Bi2Te3 bulk materials without adding dopants. (C) 2010 Elsevier B.V. All rights reserved.