Abstract
A crystal with a layered structure was found to have a large thermoelectric power factor. The in-plane power factor at 300 K is with resistivity (ρ) of 1.7 mΩ cm and thermopower (S) of -251 μV/K, and this value is comparable to that of the best thermoelectric material, alloy. The electrical resistivity shows both metallic and highly anisotropic behaviors, suggesting that the electronic structure of this crystal has a quasi-two-dimensional nature. The large thermoelectric response can be ascribed to the large density of states just above the Fermi energy and inter-valley scattering. In spite of the large power factor, the figure of merit of is 0.16 at 300 K, because of relatively large thermal conductivity, 68 mW/K cm. However, most of this value comes from reducible lattice contribution. Thus, can be improved by reducing lattice thermal conductivity, e.g., by introducing a rattling unit into the inter-layer sites.
- Received 23 August 2001
DOI:https://doi.org/10.1103/PhysRevB.64.241104
©2001 American Physical Society