Fabrication and Thermoelectric Properties of Cu-doped Bi-Te-Se Bulk Materials

Abstract

Dense n-type Bi₂Te_2.85Se_0.15 bulk thermoelectric materials with Cu doping were fabricated by mechanical alloying (MA) and spark plasma sintering (SPS) technique. The effect of Cu doping on microstructure and thermoelectric properties of Cu_xBi₂Te_2.85Se_0.15 has been investigated. At a sintering temperature of 300 °C, the effect of Cu doping on thermoelectric properties was not significant. At 400 °C, however, the carrier concentration decreased significantly with increasing Cu content, and thus causing a significant increase in the Seebeck coefficient. A largest dimensionless figure of merit value of 0.58 was achieved at room temperature for Cu_0.03Bi₂Te_2.85Se_0.15 sample sintered at 400°C.