Thermoelectric figure of merit of Bi/Pb1-xEuxTe superlattices

An enhanced thermoelectric figure of merit Z(3D)T is predicted for Bi/(111)Pb1-xEuxTe superlattices. The values of Z(3D)T obtained for x approximate to1 superlattices are 2.31, 1.55, and 1.61 at 300, 150, and 77 K, respectively, showing that they are promising candidates for thermoelectric elements in the temperature range 77-300 K. Even with x as small as 0.1, where the conduction-band offset DeltaE(c) is estimated to be 0.25 eV, the predicted Z(3D)T values are 1.75, 1.16, and 1.18 at 300, 150, and 77 K, respectively. It is proposed that other families of Bi-based superlattices, such as Bi/(111)CdTe superlattices, should also be good candidates for low-temperature thermoelectric elements.