Thermoelectric properties of P-type bismuth telluride powders synthesized by a mechano-chemical process

P-type bismuth telluride thermoelectric (TE) powders were synthesized by a mechano-chemical process (MCP) in which a mixture of Bi sulfate, Sb chlorides, and TeO 2 powders was dried, calcinated, and reduced to a powder alloy with ternary composition. The synthesized powders were a few micrometers in size, with a clear Bi 0.5 Sb 1.5 Te 3 phase. The powders were consolidated into p-type bismuth telluride bulk materials that exhibited an electrical resistivity of 0.6×10 −5 Ωm, a Seebeck coefficient of 140 μVK −1 , and a thermal conductivity of 1.3 Wm −1 K −1 at 298 K. Dimensionless figures-of-merit increased from 0.8 to 1.18 as the temperature increased from 298 K to 450 K. The results show that MCP is a promising process for the production of p-type bismuth telluride powders as raw materials for high-performance TE bulk alloys.