Published online by Cambridge University Press: 01 February 2011
Typically, useful thermoelectrics are small-gap semiconductors. Mo3Sb7 would be an interesting candidate, if it were not metallic. Electronic structure calculations reveal that metallic Mo3Sb7 can be made semiconducting by heavy doping, e.g., by replacing Sb in part with Te. We succeeded in the preparation of semiconducting Mo3Sb5-xTe2+x with enhanced thermoelectric properties. Furthermore, we incorporated small M atoms into the cubic Sb/Te cage in an attempt to create the rattling effect as found in the filled skutterudites that have attracted wide interest for their outstanding thermoelectric properties.