Increase in the Figure of Merit by Cd‐Substitution in Sn1–xPbxTe and Effect of Pb/Sn Ratio on Thermoelectric Properties

The effects of Cd‐doping on the thermoelectric properties of Sn1–xPbxTe are investigated and compared to the properties of the corresponding Sn1–xPbxTe 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 Sn1–xPbxTe. A significant increase in the power factor accompanied by a reduction in the thermal conductivity result in a higher figure of merit (ZT) for (Sn1–xPbx)0.97Cd0.03Te than that of undoped Sn1–xPbxTe. 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.