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| Autori principali: | , , , , , , |
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| Natura: | Artículo Open Access |
| Pubblicazione: |
Wiley
2024
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| Soggetti: | |
| Accesso online: | https://onlinelibrary.wiley.com/doi/10.1002/ece2.89 |
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Sommario:
- Thermoelectric performance enhancement of environmentally‐friendly SrTiO3 epitaxial films by hydrogen substitution Masatoshi Kimura Masahiro Ochiai Xinyi He Takayoshi Katase Hidenori Hiramatsu Hideo Hosono Toshio Kamiya EcoEnergy AbstractDeveloping high‐efficiency and environmentally‐friendly thermoelectric materials has been a significant challenge. Conventional thermometric materials consist of heavy (toxic) elements to reduce thermal conductivity (κ), while we demonstrated light‐element hydride anion (H−) substitution in SrTiO3 can largely reduce κ and enhance thermometric efficiency (ZT) without heavy elements. In this paper, we succeeded in maximizing the ZT of SrTiO3−xHx by applying topochemical reaction directly to SrTiO3 epitaxial films with CaH2, which realized wide‐range control of carrier concentration (ne) from 1.5 × 1020 cm−3 to 4.1 × 1021 cm−3. The power factor (PF) showed a dome‐shaped behavior with respect to ne, and the maximum PF = 22.5 μW/(cmK2) was obtained at the optimal ne = 3.4 × 1020 cm−3. Carrier transport analyses clarified that the carrier mobility was limited by impurity scattering of H‐related impurities in the SrTiO3−xHx films, while the hydrogen substitution induced a much lower κ of 4.6 W/(mK) than other heavy‐element substituted Sr1−xLaxTiO3 and SrTi1−xNbxO3 films in the wide ne range, resulting in the higher ZT value of 0.14 in maximum at room temperature. In addition, the ZT increased to 0.17 at 373 K due to the large decrease in κ for a SrTiO3−xHx film with the hydrogen concentration of 1.2 × 1021 cm−3. Further study on H− substitution approach and modulation of the H state in transition metal oxides would lead to development of high ZT environmentally‐friendly thermoelectric materials. 10.1002/ece2.89 http://creativecommons.org/licenses/by/4.0/