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

Coevaporated bismuth-tellurium and antimony-tellurium films were fabricated under various deposition conditions scontrolled evaporation rates of individual species, substrate temperature, and substrate materiald, and their thermoelectric sTEd properties sSeebeck coefficient, electrical resistivity, and carrier concentrationd 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 susing microprobe and x-ray diffractometer, respectivelyd, analyzed, and compared with available standard Bi2Te3 and Sb2Te3 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. © 2005 American Institute of Physics. fDOI: 10.1063/1.1914948g