Fabrication and Thermoelectric Properties of n-Type SbI3-Doped Bi2Te2.85Se0.15 Compounds by Hot Extrusion

The n-type 0.1 wt% SbI3-doped Bi2Te2.85Se0.15 compounds were fabricated by hot extrusion in the temperature range 300–510°C under an extrusion ratio of 20:1. The extruded compounds were highly dense. The grains were small, equiaxed (∼1.0 μm), and contained many dislocations due to the dynamic recrystallization during the extrusion. The grains were also preferentially oriented through the extrusion. The bending strength and the Fig. 1 of merit of the compounds, hot-extruded at 440°C, were 97 MPa and 2.62 × 10−3/K, respectively.