Microstructure and thermoelectric properties of n-type 95Bi_2Te_3-5Bi_2Se_3 alloy produced by rapid solidification and hot extrusion

摘要

n-type SbI_3-doped Bi_2Te_(2.85)Se_(0.15) compounds were prepared by a rapid solidification and extrusion at the temperature range 420～480°C using a ratio of 25:1. The microstructure and thermoelectric properties of the compounds were investigated. The fabricated powder consists of homogeneous Bi_ 2Te_3+Bi_2Se_3 solid solution and the theoretical density of over 99% was obtained by hot extrusion. The values of Seebeck coefficient for the compounds hot extruded at 420, 450, and 480□ were -160.8, -170.2, and -165.7□ E K~(-1) respectively. The values of electrical resistivit y(□) for the compounds hot extruded at 420, 450, and 480□ were 0.49, 0.57, and 0.51x 10~(-5)□ m, respectively. The maximum value of power factor of the compounds hot extruded at 480°C was 5.384mW/mK~2.