Ambipolar Seebeck power generator based on topological insulator surfaces

摘要

We propose a thermoelectric (TE) energy conversion device based on the surface of a three-dimensional topological insulator (TI) that is magnetically gap-opened and ionically disordered. A pair of top and bottom surfaces of a single TI film takes the role of a vertical p-n junction with ambipolar conduction, which can be considered as a TE module consisting of two dissimilar TE materials. By tuning the surface carrier screening by means of electric gating, we find that the figure of merit ZT of the device exceeds 1 in the low-temperature-regime below 300K. Our model may represent one direction for the implementation of TE energy conversion and heat management in nanodevices.