Thermoelectric properties of n-type SbI3-doped Bi2Te2.85Se0.15 compound fabricated by hot pressing and hot extrusion

n-type 0.1 wt% SbI₃-doped Bi₂Te_2.85Se_0.15 compounds were fabricated by hot pressing and hot extrusion. The hot pressed compounds were densified up to 99.2% of theoretical density. The grains were preferentially oriented and contained many dislocations due to the hot pressing. The figure of merit of the compounds hot pressed at 420°C was 2.35 × 10_-3/K. On the other hand, the grains of the extruded compounds were small, equiaxed, (1.0 m) and contained many dislocations due to the dynamic recrystallization during the extrusion. The fine grains significantly improved the bending strength and figure of merit. The grains were also preferentially oriented through the extrusion. The bending strength and figure of merit were increased with increasing extrusion temperature. The figure of merit of the compounds hot extruded at 440°C was 2.62 × 10_-3/K.