2014 Volume 55 Issue 6 Pages 942-946
A system for measuring Seebeck coefficient was constructed and applied to Bi2Te3−xSex (x = 0.15–0.6) samples without harmful dopants, prepared by mechanical alloying (MA) followed by hot pressing (HP). The constructed thermal contact method system, using single and multiple ΔT values, gave Seebeck coefficients of a standard reference material (SRM 3451) at room temperature confirmable as −230 ± 4 and −232 ± 1 µV/K, respectively. X-ray diffraction patterns and differential scanning calorimetry curves showed that the MA–HP-sintered samples of Bi2Te3−xSex were single-phase Bi2(Te,Se)3-related materials. All the Bi2Te3−xSex samples were n-type semiconductors. The maximum power factor was 1.4 × 10−3 W m−1 K−2 for Bi2Te2.8Se0.2 sintered at 623 K. These results indicated that doping with harmful materials of Bi2Te3−xSex compounds prepared by the MA–HP process is not necessary for carrier control.