Enhanced Thermoelectric Performance of c-Axis-Oriented Epitaxial Ba-Doped BiCuSeO Thin Films.

ABSTRACT: We reported the epitaxial growth of c-axis-oriented Bi_1-xBa_xCuSeO (0 ≤ x ≤ 10%) thin films and investigated the effect of Ba doping on the structure, valence state of elements, and thermoelectric properties of the films. X-ray photoelectron spectroscopy analysis reveal that Bi³⁺ is partially reduced to the lower valence state after Ba doping, while Cu and Se ions still exist as + 1 and - 2 valence state, respectively. As the Ba doping content increases, both resistivity and Seebeck coefficient decrease because of the increased hole carrier concentration. A large power factor, as high as 1.24 mWm^-1 K^-2 at 673 K, has been achieved in the 7.5% Ba-doped BiCuSeO thin film, which is 1.5 times higher than those reported for the corresponding

SUBMITTER: Yuan D 

PROVIDER: S-EPMC6261905 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature