Journal article High Power Factor with Compositional and Temperature Stabilities in (Ca x Sr1–x)Si2 Thin Films near Room Temperature
Kodai Aoyama (author) (Search by this author)
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Takayoshi Katase (author) (Search by this author)
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Yoshisato Kimura (author) (Search by this author)
;
Hiroshi Funakubo (author) (Search by this author)
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Citation
Kodai Aoyama, Takao Shimizu, Takayoshi Katase, Yoshisato Kimura, Hiroshi Funakubo. High Power Factor with Compositional and Temperature Stabilities in (Ca x Sr1–x)Si2 Thin Films near Room Temperature. ACS Applied Energy Materials. 2025, 8 (16), 12092-12098. https://doi.org/10.1021/acsaem.5c01558

Description:

(abstract)

The effects of Ca content (x) on the crystalline phases and thermoelectric properties of (CaxSr1–x)Si2 films were investigated. The solubility limit of the cubic phase was found to be narrow, with x = 0.08, compared to that of arc-melted samples. For x ≥ 0.17, a mixed phase was observed, which included a layer phase not previously reported in the arc-melted samples. In both the single cubic-phase region and the mixed-phase regions, the electrical resistivity and Seebeck coefficient varied systematically with x at 323 K. Consequently, a high power factor of approximately 1000 μW m–1 K–2 was achieved over a wide composition range (x = 0.03 to 0.17) at 323 K. The wide compositional tolerance for a high power factor is advantageous for practical fabrication and offers robustness against compositional fluctuations. In addition, the power factor remained above 850 μW m–1 K–2 within the temperature range of 223 to 373 K for x = 0.04 to 0.13. These results highlight that (CaxSr1–x)Si2 films with a predominantly cubic phase are promising candidates for thermoelectric applications near room temperature due to their high power factor across a broad range of compositions and temperatures. Furthermore, the highest power factor of 2000 μW m–1 K–2 was achieved at 210 K for the film with x = 0.04, which consisted solely of the cubic phase. The value exceeds that of previously reported SrSi2 films prepared using the same sputtering method.

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  • In Copyright

    This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Energy Materials, copyright © 2025 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acsaem.5c01558.

Keyword: Thermoelectrics, Electronic property, Crystal structure, Silicide, Sputtering

Date published: 2025-08-25

Publisher: American Chemical Society (ACS)

Journal:

  • ACS Applied Energy Materials (ISSN: 25740962) vol. 8 issue. 16 p. 12092-12098

Funding:

  • Ministry of Education, Culture, Sports, Science and Technology JPMXP1122683430

Manuscript type: Author's version (Accepted manuscript)

MDR DOI: https://doi.org/10.48505/nims.6033

First published URL: https://doi.org/10.1021/acsaem.5c01558

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Updated at: 2026-04-30 12:01:11 +0900

Published on MDR: 2026-08-07 08:33:06 +0900

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