Thermoelectric properties of the tetradymite-type Bi 2Te 2S–Sb 2Te 2S solid solution

• Published in: Materials research bulletin Vol. 44; no. 9; pp. 1926 - 1929
• Main Authors: Grauer, D.C., Hor, Y.S., Williams, A.J., Cava, R.J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2009
• Subjects: A. Chalcogenides; C. X-ray diffraction; D. Electrical properties; D. Semiconductivity; D. Thermal conductivity; C. X-ray diffraction; A. Chalcogenides; D. Semiconductivity; D. Thermal conductivity; D. Electrical properties
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2009.05.002

The thermoelectric properties of the tetradymite-type Bi 2− x Sb x Te 2S solid solution (0 ≤ x ≤ 2) are reported for the temperature range 5–300 K. The properties of non-stoichiometric, Cl and Sn doped n- and p-type variants are reported as well. The Seebeck coefficients for these materials range from −170 to +270 μV K −1 while the resistivities range from those of semimetals, 2 mΩ cm, to semiconductors, >1000 mΩ cm. Thermal conductivities were low for most compositions, typically 1.5 W m −1 K −1. Nominally undoped Bi 2Te 2S shows the highest thermoelectric efficiency amongst the tested materials with a ZT = 0.26 at 300 K that decreased to 0.04 at 100 K. The crystal structure of Sb 2Te 2S, a novel tetradymite-type material, is also reported.