Convergence of multi-valley bands as the electronic origin of high thermoelectric performance in CoSb3 skutterudites.

Published

Journal Article

Filled skutterudites R(x)Co4Sb12 are excellent n-type thermoelectric materials owing to their high electronic mobility and high effective mass, combined with low thermal conductivity associated with the addition of filler atoms into the void site. The favourable electronic band structure in n-type CoSb3 is typically attributed to threefold degeneracy at the conduction band minimum accompanied by linear band behaviour at higher carrier concentrations, which is thought to be related to the increase in effective mass as the doping level increases. Using combined experimental and computational studies, we show instead that a secondary conduction band with 12 conducting carrier pockets (which converges with the primary band at high temperatures) is responsible for the extraordinary thermoelectric performance of n-type CoSb3 skutterudites. A theoretical explanation is also provided as to why the linear (or Kane-type) band feature is not beneficial for thermoelectrics.

Full Text

Duke Authors

Cited Authors

  • Tang, Y; Gibbs, ZM; Agapito, LA; Li, G; Kim, H-S; Nardelli, MB; Curtarolo, S; Snyder, GJ

Published Date

  • December 2015

Published In

Volume / Issue

  • 14 / 12

Start / End Page

  • 1223 - 1228

PubMed ID

  • 26436339

Pubmed Central ID

  • 26436339

International Standard Serial Number (ISSN)

  • 1476-1122

Digital Object Identifier (DOI)

  • 10.1038/nmat4430

Language

  • eng