Thermoelectric properties of (BixSb1−x)2Te3 single crystal solid solutions grown by the T.H.M. method

From the experimental determination of the Te-rich comer of the Bi-Sb-Te phase diagram, single crystal solid solutions with compositions Bi8Sb32Te60, Bi9Sb31Te60 and Bi10Sb30Te60 have been grown using the Traveling Heater Method (T.H.M.). A thermoelectric characterization of samples of these p-type solid solutions is carried out as a function of stoichiometric deviations. Highly pure samples were prepared from single crystalline ingots using an annealing saturation technique at temperatures between 510 and 570°C. With the help of measurements of electrical and thermal conductivities and the Seebeck coefficient at room temperature, a maximum in the figure of merit Z = 3.2 × 10−3 K−1 was determined for the solid solution with a composition Bi9Sb31Te60.