Thermoelectric figure of merit of Bi/Pb_{1-x}Eu_{x}Te superlattices

摘要

An enhanced thermoelectric figure of merit Z_{3D}T is predicted for Bi/(111)Pb_{1-x}Eu_{x}Te superlattices. The values of Z_{3D}T obtained for x≈1 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 ΔE_{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.