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arXiv · 1002.1341

In-plane transport and enhanced thermoelectric performance in thin films of the topological insulators Bi_2Te_3 and Bi_2Se_3

Pouyan Ghaemi·Roger Mong·Joel E. Moore
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Abstract

Several small-bandgap semiconductors are now known to have protected metallic surface states as a consequence of the topology of the bulk electron wavefunctions. The known "topological insulators" with this behavior include the important thermoelectric materials Bi_2Te_3 and Bi_2Se_3, whose surfaces are observed in photoemission experiments to have an unusual electronic structure with a single Dirac cone. We study in-plane (i.e., horizontal) transport in thin films made of these materials. The surface states from top and bottom surfaces hybridize, and conventional diffusive transport predicts that the tunable hybridization-induced band gap leads to increased thermoelectric performance at low temperatures. Beyond simple diffusive transport, the conductivity shows a crossover from the spin-orbit induced anti-localization at a single surface to ordinary localization.

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Pouyan Ghaemi, Roger Mong, Joel E. Moore. 2010-04-09. In-plane transport and enhanced thermoelectric performance in thin films of the topological insulators Bi_2Te_3 and Bi_2Se_3. https://doi.org/10.1103/physrevlett.105.166603

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