The band structure of the novel low-temperature thermoelectric material, \CBT, is calculated and analyzed using the semi-classic transport equations. It is shown that to obtain a quantitative agreement with measured transport properties a band gap of 0.08 eV must be enforced. A gap in reasonable agreement with experiment was obtained using the generalized gradient functional of Engel and Vosko. We found that the experimental p-type sample has a carrier concentration close to optimal. Furthermore the conduction bands have a form equally well suited for thermoelectric properties and we predict that an optimally doped n-type compound could have thermoelectric properties exceeding those of the p-type.
@article{arxiv.cond-mat/0604303,
title = {Electronic structure and transport in CsBi$_4$Te$_6$},
author = {Lars Lykke and Bo B. Iversen and Georg K. H. Madsen},
journal= {arXiv preprint arXiv:cond-mat/0604303},
year = {2007}
}