Increase in the figure of merit by cd-substitution in Sn 1-x Pb x Te and effect of pb/sn ratio on thermoelectric properties

Abstract

The effects of Cd-doping on the thermoelectric properties of Sn 1-x Pb x Te are investigated and compared to the properties of the corresponding Sn 1-x Pb x Te solid solutions. The addition of Cd results in a reduction in the carrier concentration and changes in the physical properties, as well as in the conduction type of Sn 1-x Pb x Te. A signifi cant increase in the power factor accompanied by a reduction in the thermal conductivity result in a higher fi gure of merit (ZT) for (Sn 1-x Pb x ) 0.97 Cd 0.03 Te than that of undoped Sn 1-x Pb x Te. The maximum ZT ( ̃ 0.7) values are observed for p-type material with x = 0.36 at 560 K. Much higher values (ZT ̃ 1.2 at 560 K for x = 0.73) are obtained on n-type samples. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.