Electrochromics: A Selection of Papers from the 4th International Meeting on Electrochromics, Upp... more Electrochromics: A Selection of Papers from the 4th International Meeting on Electrochromics, Uppsala, Sweden, 21-23 August 2000
We survey some recent work related to electrochromic W-oxide-based thin films. The electronic str... more We survey some recent work related to electrochromic W-oxide-based thin films. The electronic structure of cubic (perovskite) WO3 and HWO3 was calculated from first principles. It was found, among other things, that hydroxide formation was energetically favored. Experimental studies were made on films prepared by reactive magnetron sputtering in Ar + O2 with and without CF4 addition and substrate bias. Structural studies by atomic force microscopy, x-ray diffraction, infrared reflectance spectroscopy, and Raman spectroscopy indicated that the electron bombardment associated with a positive substrate bias led to grain growth and partial crystallization while maintaining a high density of W equals O double bonds presumably on internal surfaces. Electrochemical and spectrophotometric measurements demonstrated, in particular, that tandem films -- with a thin protective layer of electron bombarded oxide covering a thicker oxyfluoride layer -- were able to combine rapid dynamics of the el...
Solar Energy Materials and Solar Cells - SOLAR ENERG MATER SOLAR CELLS, 1996
Reactive DC magnetron sputtering of W was performed in a plasma of Ar + O2 with and without CF4 a... more Reactive DC magnetron sputtering of W was performed in a plasma of Ar + O2 with and without CF4 addition and a positive substrate bias. The durability under extended Li+ intercalation/ deintercalation was excellent for electron bombarded oxide films and poor for oxyfluoride films, while the electrochromic colour/bleach dynamics was slow for the electron bombarded oxide but fast for the oxyfluoride. The range of optical modulation was large. Tandem films, with a thin protective layer of electron bombarded oxide covering a thicker oxyfluoride layer, were able to combine rapid dynamics with good durability.
This report describes composite proton electrolytes composed of nanosize activated aluminium oxid... more This report describes composite proton electrolytes composed of nanosize activated aluminium oxide particles with different surface acidity suspended in a poly(vinyl acetate)/glycerine matrix. The conductivity of the composite was found to increase by going from basic to neutral to acidic aluminium oxide. Tests in laminated electrochromic devices with tungsten oxide and nickel hydroxide films showed that the acidic electrolyte is compatible with WO3, the basic electrolyte is compatible with Ni(OH)2, and the neutral electrolyte is compatible with both of the electrodes.
This report describes composite proton electrolytes composed of nanosize zirconium phosphate or a... more This report describes composite proton electrolytes composed of nanosize zirconium phosphate or antimonic acid particles suspended in a poly(vinyl acetate)/glycerin gel matrix. The proton conductivity was 10−3–10−4 S/cm at room temperature, thermal stability prevailed up to at least 110°C, and compatibility was found with oxide electrodes; these properties makes the electrolyte suitable for use in solid state electrochemical devices. The
ABSTRACT Zr{endash}Ce oxide films were made by reactive dc magnetron cosputtering. The elemental ... more ABSTRACT Zr{endash}Ce oxide films were made by reactive dc magnetron cosputtering. The elemental composition was determined by Rutherford backscattering spectrometery and the crystalline structure by x-ray diffraction. Li intercalation/deintercalation was accomplished potentiodynamically in a liquid electrolyte. The films remained fully transparent irrespective of their degree of lithiation, which may be reconciled with a population/depopulation of Ce 4f levels. {copyright} {ital 1997 American Institute of Physics.}
Thin films of IrMgyOz with 2<y<5 were produced by reactive dc magnetron sputtering. Electro... more Thin films of IrMgyOz with 2<y<5 were produced by reactive dc magnetron sputtering. Electrochromism was investigated by voltammetric cycling in proprionic acid and by spectrophotometry. The Mg addition yielded enhanced optical modulation and bleached state transparency, while good cycling durability prevailed.
Thin films were produced by sputtering of metallic Ni in Ar/O2 and Ar/O2/H2 atmospheres. Systemat... more Thin films were produced by sputtering of metallic Ni in Ar/O2 and Ar/O2/H2 atmospheres. Systematic studies of these films were carried out in electrochromic devices with tungsten oxide and either proton or lithium conducting electrolytes. No major difference was found between devices using nickel oxide films made in the presence or absence of hydrogen. A practically important result is that both kinds of nickel films can be laminated in devices with tungsten oxide without precycling any of the films in a liquid electrolyte. Devices with the used Li+ and H+ conducting electrolytes have similar properties, suggesting that all of them may be relying on proton transport, presumably originating from adsorbed water. From a theoretical point of view, attention is drawn to the fact that the top of the NiO valence band consists of Ni 3d electron states, in contrast to the O 2p states at hand for most other electrochromic oxides. The anodic electrochromism of nickel oxide may be explained by assuming that the 3d electrons can be reversibly extracted from and inserted into the film without affecting the metal–oxygen bonds.
... 6. Spectral transmittance through films of W???Ce oxide (a) and Ti???Ce oxide (b). Data were ... more ... 6. Spectral transmittance through films of W???Ce oxide (a) and Ti???Ce oxide (b). Data were taken for films in as-deposited, Li + intercalated, and deintercalated states. ... Solar Cells, 39 (1995), p. 349. 9 A. Azens, L. Kullman, DD Ragan, CG Granqvist, B. Hj??rvarsson and G. Vaivars. ...
Electrochromics: A Selection of Papers from the 4th International Meeting on Electrochromics, Upp... more Electrochromics: A Selection of Papers from the 4th International Meeting on Electrochromics, Uppsala, Sweden, 21-23 August 2000
We survey some recent work related to electrochromic W-oxide-based thin films. The electronic str... more We survey some recent work related to electrochromic W-oxide-based thin films. The electronic structure of cubic (perovskite) WO3 and HWO3 was calculated from first principles. It was found, among other things, that hydroxide formation was energetically favored. Experimental studies were made on films prepared by reactive magnetron sputtering in Ar + O2 with and without CF4 addition and substrate bias. Structural studies by atomic force microscopy, x-ray diffraction, infrared reflectance spectroscopy, and Raman spectroscopy indicated that the electron bombardment associated with a positive substrate bias led to grain growth and partial crystallization while maintaining a high density of W equals O double bonds presumably on internal surfaces. Electrochemical and spectrophotometric measurements demonstrated, in particular, that tandem films -- with a thin protective layer of electron bombarded oxide covering a thicker oxyfluoride layer -- were able to combine rapid dynamics of the el...
Solar Energy Materials and Solar Cells - SOLAR ENERG MATER SOLAR CELLS, 1996
Reactive DC magnetron sputtering of W was performed in a plasma of Ar + O2 with and without CF4 a... more Reactive DC magnetron sputtering of W was performed in a plasma of Ar + O2 with and without CF4 addition and a positive substrate bias. The durability under extended Li+ intercalation/ deintercalation was excellent for electron bombarded oxide films and poor for oxyfluoride films, while the electrochromic colour/bleach dynamics was slow for the electron bombarded oxide but fast for the oxyfluoride. The range of optical modulation was large. Tandem films, with a thin protective layer of electron bombarded oxide covering a thicker oxyfluoride layer, were able to combine rapid dynamics with good durability.
This report describes composite proton electrolytes composed of nanosize activated aluminium oxid... more This report describes composite proton electrolytes composed of nanosize activated aluminium oxide particles with different surface acidity suspended in a poly(vinyl acetate)/glycerine matrix. The conductivity of the composite was found to increase by going from basic to neutral to acidic aluminium oxide. Tests in laminated electrochromic devices with tungsten oxide and nickel hydroxide films showed that the acidic electrolyte is compatible with WO3, the basic electrolyte is compatible with Ni(OH)2, and the neutral electrolyte is compatible with both of the electrodes.
This report describes composite proton electrolytes composed of nanosize zirconium phosphate or a... more This report describes composite proton electrolytes composed of nanosize zirconium phosphate or antimonic acid particles suspended in a poly(vinyl acetate)/glycerin gel matrix. The proton conductivity was 10−3–10−4 S/cm at room temperature, thermal stability prevailed up to at least 110°C, and compatibility was found with oxide electrodes; these properties makes the electrolyte suitable for use in solid state electrochemical devices. The
ABSTRACT Zr{endash}Ce oxide films were made by reactive dc magnetron cosputtering. The elemental ... more ABSTRACT Zr{endash}Ce oxide films were made by reactive dc magnetron cosputtering. The elemental composition was determined by Rutherford backscattering spectrometery and the crystalline structure by x-ray diffraction. Li intercalation/deintercalation was accomplished potentiodynamically in a liquid electrolyte. The films remained fully transparent irrespective of their degree of lithiation, which may be reconciled with a population/depopulation of Ce 4f levels. {copyright} {ital 1997 American Institute of Physics.}
Thin films of IrMgyOz with 2<y<5 were produced by reactive dc magnetron sputtering. Electro... more Thin films of IrMgyOz with 2<y<5 were produced by reactive dc magnetron sputtering. Electrochromism was investigated by voltammetric cycling in proprionic acid and by spectrophotometry. The Mg addition yielded enhanced optical modulation and bleached state transparency, while good cycling durability prevailed.
Thin films were produced by sputtering of metallic Ni in Ar/O2 and Ar/O2/H2 atmospheres. Systemat... more Thin films were produced by sputtering of metallic Ni in Ar/O2 and Ar/O2/H2 atmospheres. Systematic studies of these films were carried out in electrochromic devices with tungsten oxide and either proton or lithium conducting electrolytes. No major difference was found between devices using nickel oxide films made in the presence or absence of hydrogen. A practically important result is that both kinds of nickel films can be laminated in devices with tungsten oxide without precycling any of the films in a liquid electrolyte. Devices with the used Li+ and H+ conducting electrolytes have similar properties, suggesting that all of them may be relying on proton transport, presumably originating from adsorbed water. From a theoretical point of view, attention is drawn to the fact that the top of the NiO valence band consists of Ni 3d electron states, in contrast to the O 2p states at hand for most other electrochromic oxides. The anodic electrochromism of nickel oxide may be explained by assuming that the 3d electrons can be reversibly extracted from and inserted into the film without affecting the metal–oxygen bonds.
... 6. Spectral transmittance through films of W???Ce oxide (a) and Ti???Ce oxide (b). Data were ... more ... 6. Spectral transmittance through films of W???Ce oxide (a) and Ti???Ce oxide (b). Data were taken for films in as-deposited, Li + intercalated, and deintercalated states. ... Solar Cells, 39 (1995), p. 349. 9 A. Azens, L. Kullman, DD Ragan, CG Granqvist, B. Hj??rvarsson and G. Vaivars. ...
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