Thermoelectric Properties of (Bi_2Te_3)_(1-x-y)(Sb_2Te_3)_x(Sb_2Se_3)_y Single Crystals

摘要

Homogeneous and graded n- and p-type (Bi_2Te_3)_(1-x-y)(Sb_2Te_3)_x(Sb_2Se_3)_y crystals are grown by the Czochralski technique with melt supply through a floating crucible. The dimensionless thermoelectric figure of merit of the n- and p-type crystals is ZT = 1.1 (350 K) and 1.0 (375 K), respectively. It is shown that (Bi_2Te_3)_(1-x-y)(Sb_2Te_3)_x(Sb_2Se_3)_y pseudoternary solid solutions can be used to produce monolithic n- and p-type graded and segmented thermoelectric materials by Czochralski growth. The thermoelectric power distribution across the seed-crystal interface is studied using scanning hot microprobe measurements.