Effect of Ablation Rate on the Microstructure and Electrochromic Properties of Pulsed-Laser-Deposited Molybdenum Oxide Thin Films.
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| Title: | Effect of Ablation Rate on the Microstructure and Electrochromic Properties of Pulsed-Laser-Deposited Molybdenum Oxide Thin Films. |
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| Authors: | Santhosh, S.1,2, Mathankumar, M.1,2, Selva Chandrasekaran, S.1,2, Nanda Kumar, A. K.1, Murugan, P.1,2, Subramanian, B.1,2 bsmanian@cecri.res.in |
| Source: | Langmuir. Jan2017, Vol. 33 Issue 1, p19-33. 15p. |
| Subjects: | Molybdenum oxides, Metal microstructure, Electrochromic effect, Pulsed laser deposition, Laser deposition, Metallic thin films |
| Abstract: | Molybdenum trioxide (MoO3) is a well-known electrochromic material. In the present work, n-type α-MoO3 thin films with both direct and indirect band gaps were fabricated by varying the laser repetition (ablation) rate in a pulsed laser deposition (PLD) system at a constant reactive O2 pressure. The electrochromic properties of the films are compared and correlated to the microstructure and molecular-level coordination. Mixed amorphous and textured crystallites evolve at the microstructural level. At the molecular level, using NMR and EPR, we show that the change in the repetition rate results in a variation of the molybdenum coordination with oxygen: at low repetition rates (2 Hz), the larger the octahedral coordination, and greater the texture, whereas at 10 Hz, tetrahedral coordination is significant. The anion vacancies also introduce a large density of defect states into the band gap, as evidenced by XPS studies of the valence band and supported by DFT calculations. The electrochromic contrast improved remarkably by almost 100% at higher repetition rates whereas the switching speed decreased by almost 6-fold. Although the electrochromic contrast and coloration efficiency were better at higher repetition rates, the switching speed, reversibility, and stability were better at low repetition rates. This difference in the electrochromic properties of the two MoO3 films is attributed to the variation in the defect and molecular coordination states of the Mo cation. [ABSTRACT FROM AUTHOR] |
| Copyright of Langmuir is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
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| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 120696807 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Effect of Ablation Rate on the Microstructure and Electrochromic Properties of Pulsed-Laser-Deposited Molybdenum Oxide Thin Films. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Santhosh%2C+S%2E%22">Santhosh, S.</searchLink><relatesTo>1,2</relatesTo><br /><searchLink fieldCode="AR" term="%22Mathankumar%2C+M%2E%22">Mathankumar, M.</searchLink><relatesTo>1,2</relatesTo><br /><searchLink fieldCode="AR" term="%22Selva+Chandrasekaran%2C+S%2E%22">Selva Chandrasekaran, S.</searchLink><relatesTo>1,2</relatesTo><br /><searchLink fieldCode="AR" term="%22Nanda+Kumar%2C+A%2E+K%2E%22">Nanda Kumar, A. K.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Murugan%2C+P%2E%22">Murugan, P.</searchLink><relatesTo>1,2</relatesTo><br /><searchLink fieldCode="AR" term="%22Subramanian%2C+B%2E%22">Subramanian, B.</searchLink><relatesTo>1,2</relatesTo><i> bsmanian@cecri.res.in</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Langmuir%22">Langmuir</searchLink>. Jan2017, Vol. 33 Issue 1, p19-33. 15p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Molybdenum+oxides%22">Molybdenum oxides</searchLink><br /><searchLink fieldCode="DE" term="%22Metal+microstructure%22">Metal microstructure</searchLink><br /><searchLink fieldCode="DE" term="%22Electrochromic+effect%22">Electrochromic effect</searchLink><br /><searchLink fieldCode="DE" term="%22Pulsed+laser+deposition%22">Pulsed laser deposition</searchLink><br /><searchLink fieldCode="DE" term="%22Laser+deposition%22">Laser deposition</searchLink><br /><searchLink fieldCode="DE" term="%22Metallic+thin+films%22">Metallic thin films</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Molybdenum trioxide (MoO3) is a well-known electrochromic material. In the present work, n-type α-MoO3 thin films with both direct and indirect band gaps were fabricated by varying the laser repetition (ablation) rate in a pulsed laser deposition (PLD) system at a constant reactive O2 pressure. The electrochromic properties of the films are compared and correlated to the microstructure and molecular-level coordination. Mixed amorphous and textured crystallites evolve at the microstructural level. At the molecular level, using NMR and EPR, we show that the change in the repetition rate results in a variation of the molybdenum coordination with oxygen: at low repetition rates (2 Hz), the larger the octahedral coordination, and greater the texture, whereas at 10 Hz, tetrahedral coordination is significant. The anion vacancies also introduce a large density of defect states into the band gap, as evidenced by XPS studies of the valence band and supported by DFT calculations. The electrochromic contrast improved remarkably by almost 100% at higher repetition rates whereas the switching speed decreased by almost 6-fold. Although the electrochromic contrast and coloration efficiency were better at higher repetition rates, the switching speed, reversibility, and stability were better at low repetition rates. This difference in the electrochromic properties of the two MoO3 films is attributed to the variation in the defect and molecular coordination states of the Mo cation. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Langmuir is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1021/acs.langmuir.6b02940 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 15 StartPage: 19 Subjects: – SubjectFull: Molybdenum oxides Type: general – SubjectFull: Metal microstructure Type: general – SubjectFull: Electrochromic effect Type: general – SubjectFull: Pulsed laser deposition Type: general – SubjectFull: Laser deposition Type: general – SubjectFull: Metallic thin films Type: general Titles: – TitleFull: Effect of Ablation Rate on the Microstructure and Electrochromic Properties of Pulsed-Laser-Deposited Molybdenum Oxide Thin Films. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Santhosh, S. – PersonEntity: Name: NameFull: Mathankumar, M. – PersonEntity: Name: NameFull: Selva Chandrasekaran, S. – PersonEntity: Name: NameFull: Nanda Kumar, A. K. – PersonEntity: Name: NameFull: Murugan, P. – PersonEntity: Name: NameFull: Subramanian, B. IsPartOfRelationships: – BibEntity: Dates: – D: 10 M: 01 Text: Jan2017 Type: published Y: 2017 Identifiers: – Type: issn-print Value: 07437463 Numbering: – Type: volume Value: 33 – Type: issue Value: 1 Titles: – TitleFull: Langmuir Type: main |
| ResultId | 1 |
