Effect of TeI_4 Content on Thermoelectric Properties of n-type Bi_2(Te,Se)_3 Materials Prepared by Spark Plasma Sintering

摘要

The n-type Bi_2(Te,Se)_3 thermoelectric materials doped with different contents of TeI_4 were fabricated through the spark plasma sintering (SPS) technique at 693K under a pressure of 60MPa. The sintered materials were rather dense and showed preferred grain orientation. Electrical conductivity (σ), Seebeck coefficient (α), and thermal conductivity (κ) were measured in the temperature range of 300-500K. The optimal figure of merit ZT (ZT = α~2 σT/κ) of the sintered material in the direction perpendicular to the pressing direction showed a value of 0.75 for the sample containing 0.14wt% TeI_4.