Sb2Te3 and In0.2Sb1.8Te3:: a comparative study of thermoelectric and related properties

Sb2Te3 and its solid solutions with group III elements such as In are materials of current interest for their potential thermoelectric applications. Single crystals of Sb2Te3 and In0.2Sb1.8Te3 have been grown by the Bridgman method and their powder X-ray diffractograms obtained and indexed. The transport properties, namely electrical conductivity, Seebeck coefficient and thermal conductivity, as well as the optical bandgap of the alloys have been measured and are compared. The ternary alloy containing In has a smaller optical bandgap and lower electrical and thermal conductivity than Sb2Te3, but a higher Seebeck coefficient.