High thermoelectric figure of merit and thermopower in layered perovskite oxides
Abstract
We predict high thermoelectric efficiency in the layered perovskite La2Ti2O7 , based on calculations (mostly ab initio) of the electronic structure, transport coefficients, and thermal conductivity in a wide temperature range. The figure of merit Z T computed with a temperature-dependent relaxation time increases monotonically from just above 1 at room temperature to over 2.5 at 1200 K, at an optimal carrier density of around 1020cm-3 . The Seebeck thermopower coefficient is between 200 and 300 μ V /K at optimal doping, but can reach nearly 1 mV/K at low doping. Much of the potential of this material is due to its lattice thermal conductivity of order 1 W/(K m); using a model based on ab initio anharmonic calculations, we interpret this low value as due to effective phonon confinement within the layered-structure blocks.
- Publication:
-
Physical Review Materials
- Pub Date:
- February 2019
- DOI:
- 10.1103/PhysRevMaterials.3.022401
- arXiv:
- arXiv:1901.04760
- Bibcode:
- 2019PhRvM...3b2401F
- Keywords:
-
- Condensed Matter - Materials Science
- E-Print:
- 18 preprint pages, 9 figures, accepted on PR Materials