Thermoelectric performance of films in the bismuth-telluriumand antimony-tellurium systems

• Published in: Journal of applied physics 2005-05, Vol.97 (11), p.114903-114903-10
• Main Authors: da Silva, Luciana W., Kaviany, Massoud, Uher, Ctirad
• Format: Article
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.1914948

Coevaporated bismuth-tellurium and antimony-tellurium films were fabricated under various deposition conditions (controlled evaporation rates of individual species, substrate temperature, and substrate material), and their thermoelectric (TE) properties (Seebeck coefficient, electrical resistivity, and carrier concentration) were measured in search of optimal TE performance. The tellurium atomic concentration was varied from 48% to 74%, the substrate temperature ranged from 130 to 300°C, and glass, mica, magnesium oxide, and sapphire substrates were used. The chemical composition and crystal structure of the films were recorded (using microprobe and x-ray diffractometer, respectively), analyzed, and compared with available standard Bi 2 Te 3 and Sb 2 Te 3 single-crystal samples. High-performance TE films had tellurium atomic concentration around 60% and were deposited at a substrate temperature between 260 and 270°C.