Abstract
The search for new energy harvesting materials that directly convert (waste) heat into electricity has received increasing attention. Transition metal oxides are a promising class of thermoelectric (TE) materials that can operate at high temperature due to their chemical and thermal stability. However, the high lattice thermal conductivity, poor electrical conductivity, and low thermopower have significantly impeded their applications to date. Using first-principles calculations, we predict a known oxide Bi2PdO4 to be a highly efficient hole-doped TE material with low lattice thermal conductivity and high power factor. These properties are due to (i) the strong anharmonicity stemming from Bi3+ 6s2 lone pair electrons (leading to low lattice thermal conductivity) and (ii) the flat-and-dispersive valence band structure with high band degeneracy originating from the localized Pd2+ dz 2 orbitals in the stacked square planar ligand field (leading to a large power factor). Our results highlight the possibility of oxides as potential TE materials and also afford a novel strategy of designing TE materials by synthesizing compounds which combine a lone pair active cation with a d8 cation in a stacked square planar ligand field.
Original language | English (US) |
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Pages (from-to) | 2529-2534 |
Number of pages | 6 |
Journal | Chemistry of Materials |
Volume | 29 |
Issue number | 6 |
DOIs | |
State | Published - Mar 28 2017 |
Funding
J.H. acknowledges support via ONR STTR N00014-13-P-1056. S.H. acknowledges support by the U.S. Department of Energy, Office of Science Office of Basic Energy Sciences, under Award Number DE-SC0014520. Y.X., S.S.N., V.O., and C.W. acknowledge support by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Grant DE-FG02-07ER46433. This research was supported in part through the computational resources and staff contributions provided for the Quest high performance computing facility at Northwestern University which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology.
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering
- Materials Chemistry