Gasochromic windows
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| Title: | Gasochromic windows |
|---|---|
| Authors: | Wittwer, V.1, Datz, M.1, Ell, J.1, Georg, A. andreas.georg@ise.fraunhofer.de, Graf, W.1, Walze, G.1 |
| Source: | Solar Energy Materials & Solar Cells. Oct2004, Vol. 84 Issue 1-4, p305-314. 10p. |
| Subjects: | Tungsten oxides, Platinum, Hydrogen, Oxygen, Temperature, Water |
| Abstract: | Gasochromic windows can change their transmittance over a wide range. This change is caused by a thin layer of tungsten oxide (WO3), covered by a very thin layer of platinum. Exposing this coating to diluted hydrogen gas leads to reduction of the WO3, resulting in colouring. This process can be reversed by introducing diluted oxygen.The hydrogen and oxygen are produced by an electrolyser. Only small amounts of gas are needed for the switching process. The coatings are produced by sputtering. Water is needed in the WO3 films to allow rapid transport of the hydrogen. However, this water should not escape when the system is operated at higher temperatures, which can exceed 60°C. By adjusting the conditions of the sputtering process appropriately, a large amount of water can be incorporated in the films, which remains even up to temperatures above 100°C.The best transmittance values obtained for a coated double-glazed unit with a moderate film thickness (560 nm) and hydrogen concentrations below the combustion limit are 76% and 77% for solar and visual transmittance, respectively, in the bleached state and 5% and 6% for solar and visual transmittance, respectively, in the coloured state. Darker states can be obtained by applying thicker films of tungsten oxide without reducing the transmittance in the bleached state.Gasochromic coatings can also be deposited easily on plastic substrates and—because their coating structure is so simple—combined with prismatic microstructures, which allow light to be redirected. In addition, the gasochromic systems technology can be used with metal hydride systems. [Copyright &y& Elsevier] |
| Copyright of Solar Energy Materials & Solar Cells is the property of Elsevier B.V. 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.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 14188134 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Gasochromic windows – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Wittwer%2C+V%2E%22">Wittwer, V.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Datz%2C+M%2E%22">Datz, M.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Ell%2C+J%2E%22">Ell, J.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Georg%2C+A%2E%22">Georg, A.</searchLink><i> andreas.georg@ise.fraunhofer.de</i><br /><searchLink fieldCode="AR" term="%22Graf%2C+W%2E%22">Graf, W.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Walze%2C+G%2E%22">Walze, G.</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Solar+Energy+Materials+%26+Solar+Cells%22">Solar Energy Materials & Solar Cells</searchLink>. Oct2004, Vol. 84 Issue 1-4, p305-314. 10p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Tungsten+oxides%22">Tungsten oxides</searchLink><br /><searchLink fieldCode="DE" term="%22Platinum%22">Platinum</searchLink><br /><searchLink fieldCode="DE" term="%22Hydrogen%22">Hydrogen</searchLink><br /><searchLink fieldCode="DE" term="%22Oxygen%22">Oxygen</searchLink><br /><searchLink fieldCode="DE" term="%22Temperature%22">Temperature</searchLink><br /><searchLink fieldCode="DE" term="%22Water%22">Water</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Gasochromic windows can change their transmittance over a wide range. This change is caused by a thin layer of tungsten oxide (WO3), covered by a very thin layer of platinum. Exposing this coating to diluted hydrogen gas leads to reduction of the WO3, resulting in colouring. This process can be reversed by introducing diluted oxygen.The hydrogen and oxygen are produced by an electrolyser. Only small amounts of gas are needed for the switching process. The coatings are produced by sputtering. Water is needed in the WO3 films to allow rapid transport of the hydrogen. However, this water should not escape when the system is operated at higher temperatures, which can exceed 60°C. By adjusting the conditions of the sputtering process appropriately, a large amount of water can be incorporated in the films, which remains even up to temperatures above 100°C.The best transmittance values obtained for a coated double-glazed unit with a moderate film thickness (560 nm) and hydrogen concentrations below the combustion limit are 76% and 77% for solar and visual transmittance, respectively, in the bleached state and 5% and 6% for solar and visual transmittance, respectively, in the coloured state. Darker states can be obtained by applying thicker films of tungsten oxide without reducing the transmittance in the bleached state.Gasochromic coatings can also be deposited easily on plastic substrates and—because their coating structure is so simple—combined with prismatic microstructures, which allow light to be redirected. In addition, the gasochromic systems technology can be used with metal hydride systems. [Copyright &y& Elsevier] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Solar Energy Materials & Solar Cells is the property of Elsevier B.V. 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: 10.1016/j.solmat.2004.01.040 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 10 StartPage: 305 Subjects: – SubjectFull: Tungsten oxides Type: general – SubjectFull: Platinum Type: general – SubjectFull: Hydrogen Type: general – SubjectFull: Oxygen Type: general – SubjectFull: Temperature Type: general – SubjectFull: Water Type: general Titles: – TitleFull: Gasochromic windows Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Wittwer, V. – PersonEntity: Name: NameFull: Datz, M. – PersonEntity: Name: NameFull: Ell, J. – PersonEntity: Name: NameFull: Georg, A. – PersonEntity: Name: NameFull: Graf, W. – PersonEntity: Name: NameFull: Walze, G. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 10 Text: Oct2004 Type: published Y: 2004 Identifiers: – Type: issn-print Value: 09270248 Numbering: – Type: volume Value: 84 – Type: issue Value: 1-4 Titles: – TitleFull: Solar Energy Materials & Solar Cells Type: main |
| ResultId | 1 |
