Author: Ivanova L.D. Granatkina Y.V.
Publisher: MAIK Nauka/Interperiodica
ISSN: 0020-1685
Source: Inorganic Materials, Vol.37, Iss.2, 2001-02, pp. : 149-152
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Abstract
Sb_2Te_3–Bi_2Te_3 crystals (25–60 mol % Bi_2Te_3) doped with Bi_2Se_3 and excess Te were studied with the aim of identifying the optimal compositions for the p-legs of low-temperature coolers. The crystals were grown by the floating-crucible technique. Their transport properties were studied in the range 100–400 K. By measuring axial thermopower profiles, it was shown that increasing the Bi_2Te_3 and Bi_2Se_3 contents of the crystals has an adverse effect on their homogeneity. Crystals were prepared with a carrier concentration in the range (1–5) × 10^19 cm^–3 and a thermoelectric power above 200 μV/K at room temperature and the highest thermoelectric figure of merit at temperatures below 200 K. The maximum temperature drops and thermoelectric figures of merit were calculated for low-temperature stages of magnetothermoelectric coolers with hot-junction temperatures of 200 and 170 K and Bi–Sb n-legs.