Understanding the effect of thickness on the thermoelectric properties of Ca3Co4O9 thin films
Abstract We are reporting the effect of thickness on the Seebeck coefficient, electrical conductivity and power factor of Ca3Co4O9 thin films grown on single-crystal Sapphire (0001) substrate. Pulsed laser deposition (PLD) technique was employed to deposit Ca3Co4O9 films with precisely controlled th...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2021-03-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-021-85287-2 |
| _version_ | 1818841708113166336 |
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| author | Yinong Yin Ashutosh Tiwari |
| author_facet | Yinong Yin Ashutosh Tiwari |
| author_sort | Yinong Yin |
| collection | DOAJ |
| description | Abstract We are reporting the effect of thickness on the Seebeck coefficient, electrical conductivity and power factor of Ca3Co4O9 thin films grown on single-crystal Sapphire (0001) substrate. Pulsed laser deposition (PLD) technique was employed to deposit Ca3Co4O9 films with precisely controlled thickness values ranging from 15 to 75 nm. Structural characterization performed by scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that the growth of Ca3Co4O9 on Sapphire (0001) follows the island growth-mode. It was observed that in-plane grain sizes decrease from 126 to 31 nm as the thickness of the films decreases from 75 to 15 nm. The thermoelectric power measurements showed an overall increase in the value of the Seebeck coefficient as the films’ thickness decreased. The above increase in the Seebeck coefficient was accompanied with a simultaneous decrease in the electrical conductivity of the thinner films due to enhanced scattering of the charge carriers at the grain boundaries. Because of the competing mechanisms of the thickness dependence of Seebeck coefficient and electrical conductivity, the power factor of the films showed a non-monotonous functional dependence on thickness. The films with the intermediate thickness (60 nm) showed the highest power factor (~ 0.27 mW/m-K2 at 720 K). |
| first_indexed | 2024-12-19T04:30:22Z |
| format | Article |
| id | doaj.art-9696d728dd8346c5a5de5b2c75595043 |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-12-19T04:30:22Z |
| publishDate | 2021-03-01 |
| publisher | Nature Portfolio |
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| series | Scientific Reports |
| spelling | doaj.art-9696d728dd8346c5a5de5b2c755950432022-12-21T20:35:53ZengNature PortfolioScientific Reports2045-23222021-03-011111710.1038/s41598-021-85287-2Understanding the effect of thickness on the thermoelectric properties of Ca3Co4O9 thin filmsYinong Yin0Ashutosh Tiwari1Nanostructured Materials Research Laboratory, Department of Material Science and Engineering, University of UtahNanostructured Materials Research Laboratory, Department of Material Science and Engineering, University of UtahAbstract We are reporting the effect of thickness on the Seebeck coefficient, electrical conductivity and power factor of Ca3Co4O9 thin films grown on single-crystal Sapphire (0001) substrate. Pulsed laser deposition (PLD) technique was employed to deposit Ca3Co4O9 films with precisely controlled thickness values ranging from 15 to 75 nm. Structural characterization performed by scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that the growth of Ca3Co4O9 on Sapphire (0001) follows the island growth-mode. It was observed that in-plane grain sizes decrease from 126 to 31 nm as the thickness of the films decreases from 75 to 15 nm. The thermoelectric power measurements showed an overall increase in the value of the Seebeck coefficient as the films’ thickness decreased. The above increase in the Seebeck coefficient was accompanied with a simultaneous decrease in the electrical conductivity of the thinner films due to enhanced scattering of the charge carriers at the grain boundaries. Because of the competing mechanisms of the thickness dependence of Seebeck coefficient and electrical conductivity, the power factor of the films showed a non-monotonous functional dependence on thickness. The films with the intermediate thickness (60 nm) showed the highest power factor (~ 0.27 mW/m-K2 at 720 K).https://doi.org/10.1038/s41598-021-85287-2 |
| spellingShingle | Yinong Yin Ashutosh Tiwari Understanding the effect of thickness on the thermoelectric properties of Ca3Co4O9 thin films Scientific Reports |
| title | Understanding the effect of thickness on the thermoelectric properties of Ca3Co4O9 thin films |
| title_full | Understanding the effect of thickness on the thermoelectric properties of Ca3Co4O9 thin films |
| title_fullStr | Understanding the effect of thickness on the thermoelectric properties of Ca3Co4O9 thin films |
| title_full_unstemmed | Understanding the effect of thickness on the thermoelectric properties of Ca3Co4O9 thin films |
| title_short | Understanding the effect of thickness on the thermoelectric properties of Ca3Co4O9 thin films |
| title_sort | understanding the effect of thickness on the thermoelectric properties of ca3co4o9 thin films |
| url | https://doi.org/10.1038/s41598-021-85287-2 |
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