Does Topology Enhance Thermoelectric Efficiency? A Case Study in Bismuthene
Two-dimensional (2D) bismuth (Bi) layer, known as bismuthene, exhibits Z2 topological bulk states due to
large spin-orbit coupling that inverts the bands. Using the tight-binding method, we calculate the band
structure of buckled bismuthene to understand its topological and trivial phases. We determine the
thermoelectric properties for some considered phases, incorporating the edge states contribution,
by using the linearized Boltzmann transport equation (BTE) with a constant relaxation time approximation.
It is shown that the thermoelectric figure of merit, ZT, actually drops in undoped topological bismuthene
due to the edge effects. Surprisingly, the topological edge states enhance ZT at large doping with the
Fermi energy near the bottom of bulk bands when bismuthene is nearly metallic.
Preprint: arXiv:2105.05211 (2021)
Back to Publications