Toward enhanced thermoelectric effects in Bi₂Te₃/Sb₂Te₃heterostructures

Abstract

The possibility of enhanced thermoelectric properties through nanostructuring is investigated theoretically in a p-type Bi 2 Te 3 /Sb 2 Te 3 heterostructure. A multi-scale modeling approach is adopted to account for the atomistic characteristics of the interface as well as the carrier/phonon transport properties in the larger scales. The calculations clearly illustrate the desired impact of carrier energy filtering at the potential barrier by locally boosting the power factor over a sizable distance in the well region. Further, the phonon transport analysis illustrates a considerable reduction in the thermal conductivity at the heterointerface. Both effects are expected to provide an effective means to engineer higher zT in this material system.

Designer Topological Insulator with Enhanced Gap and Suppressed Bulk Conduction in Bi2Se3/Sb2Te3 Ultrashort-Period Superlattices

“…Another system, ZnCdSe/Bi2Se3 SLs, showed that multiple topological surface channels that scale with the number of SL periods could be obtained 22 . A few examples of the growth and properties of heterojunctions and SLs comprised of two TI materials, such as Bi2Te3/Sb2Te3, have also been previously reported [23][24][25] , however the effect of short period TI/TI SL structures on the band structure and carrier density of the resulting materials, or on their topological surface states, has not been appreciably addressed.…”