Microstructure and Thermoelectric Properties of Rapidly Solidified and Hot Pressed N-Type 95Bi_2Te_3-5Bi_2Se_3 Alloys

摘要

N-type 0.05wt% SbI_3-doped Bi_2Te_(2.85)Se_(0.15) compounds were fabricated by gas atomizing and hot pressing. The as-fabricated powder consists of homogeneous Bi_2Te_3+Bi_2Se_3 solid solution and a maximum theoretical density of 98.9% was obtained after hot pressing, resulting in improvement of compression strength up to 4-5 times of the conventionally prepared single crystal thermoelectric material. The values of the Seebeck coefficient for hot pressed specimens vertical of the pressing direction with small and large powder size were -178 and -218μV/K, respectively. The values of the electrical resistivity for hot pressed specimens vertical of the pressing direction with small and large powder with small and large powder size were 1.245 and 1.728 × 10~(-5) Ω m, respectively.