Ideal band shape in the potential thermoelectric material CuAlO 2 : Comparison to Na x CoO 2
Year: 2013
Type: article
Abstract: A potential thermoelectric material CuAlO${}_{2}$ is theoretically studied. We first construct a model Hamiltonian of CuAlO${}_{2}$ based on the first principles band calculation, and calculate the Seebeck coefficient. Then, we compare the model with that of a well-known thermoelectric material Na${}_{x}$CoO${}_{2}$, and discuss the similarities and the differences. It is found that the two materials are similar from an electronic structure viewpoint in that they have a peculiar pudding-mold type band shape, which is advantageous for thermoelectric materials. There are, however, some differences, and we analyze the origin of the difference from a microscopic viewpoint. The band shape (a very flat band top but with an overall wide bandwidth) of CuAlO${}_{2}$ is found to be even more ideal than that of Na${}_{x}$CoO${}_{2}$, and we predict that once a significant amount of holes is doped in CuAlO${}_{2}$, thermoelectric properties (especially the power factor) even better than those of Na${}_{x}$CoO${}_{2}$ can be expected.
Source: Physical Review B
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1446211287