Thermoelectric properties of (Bi2Te3)1-x-y(Sb2Te3)x(Sb2Se3)y single crystals

Homogeneous and graded n- and p-type (Bi2Te3)(1-x-y)(Sb2Te3)(x)(Sb2Se3)(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 (Bi2Te3)(1-x-y)(Sb2Te3)(x)(Sb2Se3)(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.