WO1997045767A1 - Dispositif electrochrome par electrophotochimie - Google Patents

Dispositif electrochrome par electrophotochimie Download PDF

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Publication number
WO1997045767A1
WO1997045767A1 PCT/US1997/008773 US9708773W WO9745767A1 WO 1997045767 A1 WO1997045767 A1 WO 1997045767A1 US 9708773 W US9708773 W US 9708773W WO 9745767 A1 WO9745767 A1 WO 9745767A1
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WO
WIPO (PCT)
Prior art keywords
transparent electrode
electrochromic
light
electrolyte layer
semiconductor coating
Prior art date
Application number
PCT/US1997/008773
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English (en)
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WO1997045767B1 (fr
Inventor
Clemens S. Bechinger
Brian A. Gregg
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Midwest Research Institute
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Publication date
Application filed by Midwest Research Institute filed Critical Midwest Research Institute
Priority to AU31409/97A priority Critical patent/AU3140997A/en
Publication of WO1997045767A1 publication Critical patent/WO1997045767A1/fr
Publication of WO1997045767B1 publication Critical patent/WO1997045767B1/fr

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/15—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on an electrochromic effect
    • G02F1/163—Operation of electrochromic cells, e.g. electrodeposition cells; Circuit arrangements therefor
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/15—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on an electrochromic effect
    • G02F1/153—Constructional details
    • G02F1/1533—Constructional details structural features not otherwise provided for

Definitions

  • the present invention relates to electrochromic devices which modulate the transmittance of light entering a window depending on the incident solar intensity and, in particular, relates to electrochromic devices which are self-powered to modulate the transmittance of light entering a window without needing external power supplies.
  • Patent No. 4,768,865 discloses a conventional electrochromic film on a window that is responsive to the application of an electric field to change from a high- transmittance, non-absorbing state to a lower-transmittance, absorbing or reflecting state.
  • Ito et al, U.S. Patent No. 4,958,917 discloses the use of an electrochromic coating for dimming automobile windows, including a plurality of solid electrochromic elements arranged in a horizontal abutting fashion and adhered to the glass window, each element being controllable independently of the others.
  • Hashimoto et al, U.S. Patent No. 4,958,917 discloses a specialized combination of two electrochromic cells which, together, are capable of reducing the transmittance of visible light to less than the usual lower limit of 7% for known electrochromic coatings.
  • the Mockovciak U.S. Patent 4,475,031 , discloses a self-contained sun- sensitive window made up of liquid nematic crystals (LC), sandwiched between two transparent sheets and powered directly by a solar cell.
  • LC liquid nematic crystals
  • Liquid nematic crystals are not effective in blocking heat radiation. Rather, they merely scatter light, thus making a window translucent, but not effectively blocking heat gain from the sun's rays.
  • a further disadvantage of such liquid nematic crystal technology is that a constant source of energy is required to change the translucence of the window, thus requiring a substantial and continuous source of electric power as long as transparency instead of translucence is desired.
  • Patent 5,384,653 assigned to the same assignee as the present application, describes a stand-alone photovoltaic powered electrochromic window.
  • the window of the Benson et al patent includes an electrochromic material that has been deposited on one pane of the window in conjunction with an array of photovoltaic cells deposited along an edge of the pane to produce the required electric power necessary to vary the effective transmittance of the window. While providing a self-powered electrochromic window, the window of the Benson et al patent requires increased layers in the electrochromic material in addition to using a portion of the window space for the photovoltaic array along the periphery of the window. Use of only the periphery of the window for the photovoltaic cells could result in the sunlight entering the building without actually contacting the photovoltaic cells.
  • Branz et al patent includes an electrochromic material and a photovoltaic device-type thin film solar cell deposited in a tandem type, monolithic single coating over the component.
  • a resistor is connected in series across the electrochromic material and photovoltaic device controlling the activation and deactivation of the electrochromic material.
  • the electrical conductivity between the electrochromic material and the photovoltaic device is enhanced by interposing a transparent electrically conductive layer.
  • the present invention is a photoelectrochemical-electrochromic device.
  • the device comprises a first transparent electrode and a second transparent electrode in a parallel, spaced relation to each other.
  • the first transparent electrode is electrically connected to the second transparent electrode.
  • the device of the present invention further comprises an electrochromic material applied to the first transparent electrode and a semiconductor coating applied to the second transparent electrode.
  • An electrolyte layer contacts the electrochromic material and the semiconductor coating.
  • the electrolyte layer has a redox couple whereby upon application of light, the semiconductor coating absorbs the light and the redox couple oxidizes producing an electric field across the device modulating the effective light transmittance through the device.
  • the device further comprises a first transparent substrate and a second transparent substrate.
  • the first transparent electrode is applied to the first transparent substrate and the second transparent electrode is applied to the second transparent substrate.
  • the first and second transparent substrate comprises a material selected from the group consisting of glass and plastic.
  • the electrochromic material preferably comprises a material selected from the group consisting of WO 3 , IrO,, V 2 O 5 , and NiO and the semiconductor coating layer preferably comprises a porous material of metal oxide selected from the group consisting of TiO 2 , CdS, ZnS, ZnO, and WO 3 .
  • the device of present invention preferably comprises a layer of dye applied on the surface and into the pores of the semiconductor coating layer.
  • the dye preferably comprises transition metal complexes selected from the group consisting of ML, and ML ⁇ wherein M is selected from the group consisting of Fe, Ru, Os, Cr, Mo and Mn, L comprises bipyridine-type ligand selected from the group consisting of 2,2'-bipyridine-4,4'- dicarboxylic acid and 4,4'-dimethyl-2,2'-bipyridine, and X comprises a monodentate ligand selected from the group consisting of CN, SCN, Cl, Br, I and H 2 O; poryphyrins comprising zinc tetra(4-carboxyphenyl)porphyrin; phthalocyanines comprising 4,4',4",4'"-tetraazaphthalocyanine; and perylenes comprising 3,4,9,10- perylene tetracarboxylic acid.
  • M is selected from the group consisting of Fe, Ru, Os, Cr, Mo and Mn
  • L comprises bipyridine-type lig
  • the electrolyte layer has a predetermined thickness to provide high lateral ionic conductivity to darken the entire immediately adjacent electrochromic material.
  • the electrolyte layer's thickness is less than the predetermined thickness, high lateral conductivity does not occur and only those portions of the electrochromic material adjacent the electrolyte exposed to the light will actually darken.
  • the present invention is also a method of modulating the transmittance of light. The method comprises electrically connecting a first transparent electrode and a second transparent electrode in parallel, spaced relation to each other. Next, an electrochromic material is applied to the first transparent electrode and a semiconductor coating is applied to the second transparent electrode. Then, an electrolyte layer is positioned to contact the electrochromic material and the semiconductor coating.
  • the electrolyte layer has a redox couple, whereby the first and second electrodes, the electrochromic material, the semiconductor coating, and the electrolyte layer form a photoelectrochemical-electrochromic device. Finally, the photoelectrochemical-electrochromic device is exposed to a light source wherein the semiconductor coating and/or the sensitizing dye absorbs the light and the redox couple becomes oxidized producing an electric field across the photoelectrochemical- electrochromic device to vary the effective light transmittance through the photoelectrochemical-electrochromic device.
  • the method further comprises applying the first transparent electrode to the first transparent substrate and applying the second transparent electrode to the second transparent substrate.
  • the light absorbing and transferring means comprises a dye substance, e.g., a monomolecular chromophore dye applied to the semiconductor layer.
  • the electrolyte layer has predetermined thickness to provide high lateral ionic conductivity.
  • Figure 1 illustrates a perspective view of a window incorporating the photoelectrochemical-electrochromic device of the present invention.
  • Figure 2 illustrates a diagrammatic cross sectional view of the photoelectrochemical-electrochromic device which constitutes the present invention
  • Figure 3 illustrates a perspective view of a window incorporating the present invention wherein the electrolyte layer of the photoelectrochemical-electrochromic device comprises a thickness which provides low lateral conductivity
  • Figure 4 illustrates the transmission of light through the photoelectrochemical-electrochromic device of the present invention versus time.
  • the graph illustrated in Figure 4 is derived from the experimentations by the inventors of the present invention during the invention and reduction to practice of the present invention.
  • the electrodes, electrochromic material, semiconductor coating, dye substance and electrolyte layer illustrated are representative of the types of materials available for use. Other materials, including the materials set forth below, are within the scope of the present invention.
  • Figure 5 illustrates a graph of the relative transmittance of light through the photoelectrochemical-electrochromic device of the present invention.
  • the present invention is a photoelectrochemical-electrochromic light modulating assembly, indicated generally at 10, providing a self-powered electrochromic device which automatically or selectively modulates the transmittance of incoming light through a window without the need for an external power source.
  • the modulating assembly 10 of the present invention combines an electrochromic coating with a semiconductor/electrolyte-type device providing the self-powered modulating assembly 10 of the present invention which reduces the actual number of layers typically needed for operation of an electrochromic coating compared to the prior art.
  • the modulating assembly 10 comprises a first and second transparent electrode 12, 14.
  • the first transparent electrode 12 is coated with an electrochromic material 16 and the second transparent electrode 14 is coated with a semiconductor coating 18 having an optional monomolecular layer of dye substance 20 applied thereon.
  • the first and second transparent electrodes 12, 14 are spaced apart, joined together, and electrically connected.
  • Li lithium iodide
  • the modulating assembly 10 is exposed to white light source (approximately equal to one sun) (not shown), the transmittance of the light through the modulating assembly 10 is decreased within one minute by more than 70%.
  • the modulating assembly 10 further comprises a window 24 having a first glass plate 26 and a second glass plate 28, each having peripheral edges 40.
  • the first glass plate 26 has an inner and an outer surface 30, 32 and the second glass plate 28 has an inner and outer surface 34, 36.
  • the first and second plates 26, 28 are placed in a substantially parallel and spaced-apart relation to one another, separated by at least one spacer 38 and sealed around the peripheral edges 40 of the first and second plates 26, 28 to form a cavity 42 between the first and second plates 26, 28.
  • the modulating assembly 10 of the present invention will be described as having two plates, a first and a second plate, 26, 28, it is within the scope of the present invention to have additional plates, as needed.
  • the first and second plates 26, 28 preferably comprise glass, any other transparent electrically insulating material including, but not limited to, plastic is within the scope of the present invention.
  • the first transparent electrode 12 is deposited on the inner surface 30 of the first plate 26 and the second transparent electrode 14 is deposited on the inner surface 34 of the second plate 28 by known means including, but not limited to, physical vapor deposition, sputtering, chemical vapor deposition, i.e., heat stimulated or radio frequency discharge or the like.
  • the first and second transparent electrodes 12, 14 preferably comprise highly doped metal oxides such as SnO 2 :F, SnO 2 :Sb, In 2 O 3 :Sn (ITO), Cd 2 SnO 4 , ZnO:Al and ZnO:In.
  • Particularly suitable metal oxide semiconductors are oxides of the transition metals, and of elements of the third main group and of the fourth, fifth and sixth secondary groups (of the periodic system of elements) of titanium, zirconium, hafnium, strontium, zinc, indium, yttrium, lanthanum, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, or alternatively oxides of zinc, iron, nickel or silver, perovskites such as SrTiO 3 , CaTiO 3 or oxides of other metals of the second and third main groups or mixed oxides or oxide mixtures of these metals.
  • any other conductive metal oxides or metal sulfides with semiconductor properties and a large energy gap (band gap) between the valence band and the conduction band can be used.
  • first and second transparent electrodes 12, 14 be effectively transparent to the light so that the light can reach the semiconductor coating with the optional adsorbed dye 20 for conversion to electrical energy. Furthermore, preferably, the first and second transparent electrodes 12, 14 are each between approximately 1000 to approximately 5000 angstroms thick.
  • the electrochromic material 16 is deposited on the first transparent electrode 12 sirnilar to the deposition of the first transparent electrode 12 on the first glass plate 26.
  • an electrochromic material is one that takes on and loses color, i.e., becomes opaque or transparent, in response to an electric field or current there through in the presence of an ion source adjacent to the electrochromic material, as will be discussed further below.
  • the electrochromic material 16 can be anodic or cathodic in nature and can occur in two phases, liquids and solids.
  • the electrochromic material 16 colors in a reduced state which can be induced by a DC electric current and includes, but is not limited to, WO 3 , IrO x , NiO, V 2 O 5 , MoO 3 , TiO 2 , U 2 O 5 , Bi 2 O 3 , PbO 2 , and CuO x .
  • the electrochromic material 16 of the present invention is preferably between approximately 1,000 to approximately 15,000 angstroms thick.
  • the second transparent electrode 14 is coated with a semiconductor coating 18, preferably a porous specimen of TiO 2 , with the oxidizable sensitizer or chromophore (dye) 20, for example RuL 3 4" , applied to the semiconductor coating.
  • the dye substance 20 is not required for operation of the device 10 if the semiconductor coating 18 absorbs sufficient light (operation of the device 10 of the present invention will described further below).
  • nanoporous TiO 2 films prepared by either method 1 or by method 2 as described in Nazeeruddin et al (J. Am Chem. Soc, 1993, 115. 6382) can be used in the present invention. Both methods produce satisfactory semiconductor films but method 1 produces films having better transparency.
  • the dye substance 20 In the case of the porous specimen of TiO 2 semiconductor coating 18, if the dye substance 20 is applied, the dye substance 20 actually enters the pores of the semiconductor coating 18 to thereby coat the pore surfaces with dye. It should be noted that different dye substances 20 have different spectral sensitivities. The dye substance 20 can thus be adapted to absorb light in a desired spectral region while transmitting light in other spectral regions.
  • suitable dye substances 20, i.e., sensitizers are complexes of transition metals of the type selected from the group consisting of ML 3 and ML 2 X 2 wherein M is selected from the group consisting of Fe, Ru, Os, Cr, Mo and Mn, L comprises bipyridine-type ligand selected from the group consisting of 2,2'-bipyridine-4,4'-dicarboxylic acid and 4,4'-dimethyl-2,2'- bipyridine, and X comprises a monodentate ligand selected from the group consisting of CN, SCN, Cl, Br, I and H 2 O; poryphyrins comprising zinc tetra(4-carboxyphenyl) porphyrin; phthalocyanines comprising 4,4',4",4'"-tetraazaphthalocyanine; and perylenes comprising 3,4,9, 10-perylene tetracarboxylic acid.
  • M is selected from the group consisting of Fe, Ru, Os, Cr,
  • the dye substance 20 can be chemi-sorbed, adsorbed or otherwise applied to the semiconductor 18 of the modulating assembly 10 of the present invention. It should be noted that the elements listed above for M, L, and X are merely representative of the types of elements available for use with the device of the present invention. Other elements are within the scope of the present invention.
  • the actual deposition of the electrochromic material 16 and the semiconductor coating 18 can be accomplished by evaporation techniques. Furthermore, the electrochromic material 16 and the semiconductor coating 18 can be deposited on the first and second transparent electrodes 12, 14, respectively, by dip coating, spray coating, spin coating, roll coating, or electroplating.
  • the lithium iodide (Lil) containing electrolyte 22 is then inserted between the first and second transparent electrodes 12, 14, e.g., through small holes (not shown) formed in the first plate 26 and/or the second plate 28, such that the electrolyte 22 contacts the electrochromic material 16 and the semiconductor coating 18. Upon filling of the cavity 42, the small holes are then sealed with an epoxy or medium (not shown).
  • the electrolyte 22 is designed to store ions and shuttle the ions back and forth into the electrochromic material 16 with applied potential.
  • the first transparent electrode 12 operates as an electron delivery system to transfer electrons into the electrochromic material 16 upon application of the potential produced upon light exposure.
  • the electrochromic material 16 requires the ion delivery and storage electrolyte 22 to be contacting the electrochromic material 16.
  • the electrolyte can be either liquid or solid. Solid thin-film electrolytes are made of fast-ion conductor materials in which lithium, sodium or hydrogen ions diffuse readily.
  • the electrolyte 22 includes Li, which will be described further below. Examples of other materials which are within the scope of the present invention include Li 3 N, Li 2 NH, and Lij. x M x Ti 2 . x (PO 4 ) 3 , where M represents another metal, such as aluminum, chromium, gallium, or the like.
  • a solid thin-film electrolyte may be, for example, 500 to 10,000 angstroms thick.
  • the thickness of the electrolyte 22 In order to darken the entire electrochromic material 16 of the modulating assembly 10 when light strikes any portion of the electrolyte 22 therein, the thickness of the electrolyte 22 must exceed a certain predetermined thickness to provide a high lateral ionic conductivity to darken the entire immediately adjacent electrochromic material 16. If the thickness of the electrolyte 22 is less than the predetermined thickness, then only those portions of the electrolyte 22 which have light applied thereto will actually darken the immediately adjacent electrochromic material 16. As illustrated in Figure 3, a thinner electrolyte layer 22 allows the modulating assembly
  • a thinner electrolyte layer 22 provides the modulating assembly 10 to be utilized as an imaging storage device. Images 23 can be applied to the modulating assembly 10 by an imaging projection device or similar equipment (not shown), stored thereon and then erased when desired.
  • the thickness must be greater than approximately 0.5 mm to cause high lateral ionic conductivity.
  • a first lead 44 and a second lead 46 are connected to a first terminal 48 and a second terminal 50, respectively, on the first transparent electrode 12 and the second transparent electrode 14, respectively, to provide the electrical circuit across the modulating assembly 10.
  • the electric potential across the electrochromic material 16 upon application of light causes the electrochromic material 16 to convert from essentially transparent to opaque.
  • the first and second leads 44, 46 disconnected coloration of the electrochromic material 16 will not occur.
  • variable resistor element can be inserted between the first and second leads 44, 46 in order to change the dynamics of the modulating assembly 10. The variable resistor controls the amount of potential across the first and second leads 44, 46 such that electrochromic material 16 can be made more or less dark or overridden altogether.
  • the sun or other light source shines through the window 24, a chemical reaction takes place in the modulating assembly 10.
  • the dye substance 20 absorbs the photons from the sun and electrons are injected from the dye substance 20 into the semiconductor coating 18.
  • a potential travels through the second transparent electrode 14 and into the first transparent electrode 12 through the first and second leads 44, 46.
  • the first transparent electrode 12 injects electrons into the electrochromic material 16.
  • the electrolyte 22 injects ions into the electrochromic material 16. Injection of ions and electrons into the electrochromic material 16 causes the electrochromic material 16 to darken. Removal of the sun or use of a battery as discussed above causes a reverse chemical reaction to cause the electrochromic material 16 to lighten.
  • Example 1 Tris(4,4'-dicarboxy-2,2'-bipyridine)ruthenium(II) was adsorbed from ethanol solution onto a approximately 4 ⁇ m thick nanoporous TiO ; , film by soaking overnight. The dye- sensitized electrode was then rinsed with ethanol and dried in a nitrogen stream.
  • the WO 3 electrode was prepared by thermal evaporation of 500 nm of WO 3 onto In 2 O 3 -coated glass. The two electrodes were clamped together separated by a gasket made of TYGON tubing with a hole cut therethrough. A solution of Lil in acetonitrile was injected through the gasket to fill the internal space. Upon illumination with white light from a 75 W Xe arc lamp, the cell generated an open circuit photovoltage of 0.25V. This was not sufficient to color the WO 3 electrode by itself, but decreased the externally applied voltage necessary to color the cell.
  • the open circuit voltage of the cell was approximately 0 V, consistent with the WO 3 electrode being charged up to a voltage equal and opposite to the dye-sensitized TiO 2 electrode.
  • the cell voltage was 0.45 V of the opposite polarity as the original photovoltage, consistent with the discharging of the colored WO 3 electrode.
  • the polymer electrolyte also acted as an adhesive to bond the two electrodes together.
  • the cell transmittance decreased 23% over eight minutes.
  • a cell was constructed as in Example 2 but using 0.1 M Lil in propylene carbonate containing several drops of 4-tert-butylpyridine as the electrolyte.
  • the transmission decreased 66% over 1.5 minutes exposure to white light.
  • a nanoporous TiO 2 film without any sensitizing dye was used as the semiconductor electrode in a cell made up as in Example 5. This cell developed an open circuit photovoltage of 600 mV when illuminated with white light. The transmission decreased by 35% over 12 minutes. A filter cutting out only the UV light eliminated the photoeffect in this cell consistent with a photoeffect resulting from direct excitation of the TiO 2 .
  • Example 7 A TiO 2 coated electrode was soaked overnight in an ethanol solution containing 138 ⁇ M bis(4,4'-dicarboxy-2,2'-bipyridine)(4,4'-dimethyl-2,2'- bipyridine)ruthenium(II) and 25 mM chenodeoxycholic acid.
  • a cell made from this electrode following the procedure of Example 5 showed a photovoltage of 680 mV upon exposure to white light and a change in transmission of about 70% as shown in Figure 4.
  • a TiO 2 coated electrode was soaked overnight in an ethanol solution containing 69 ⁇ M bis(4,4'-dicarboxy-2,2'-bipyridine)(4,4'-dimethyl-2,2'- bipyridine)ruthenium(II) and 12.5 mM chenodeoxycholic acid.
  • a cell made from this electrode following the procedure of Example 5 showed a photovoltage of 580 mV upon exposure to white light and a change in transmission of about 30% within 100 seconds. After blocking the white light with a shutter, spontaneous bleaching occurred leading back to the transparent state after about 200 seconds as shown in Figure 5.
  • a 5 cm x 5 cm dye-sensitized TiO 2 film was prepared by soaking overnight in an ethanol solution containing 8.3 ⁇ M bis(4,4'-dicarboxy-2,2'-bipyridine)(4,4'- dimethyl-2,2 '-bipyridine)ruthenium(II) and 29 mM chenodeoxycholic acid.
  • the WO 3 electrode was prepared by thermal evaporation of 500 nm of WO 3 onto indium tin oxide-coated glass at a temperature of 50°.
  • the TiO 2 and the WO 3 electrodes were sealed together using SURLYN 1601 strips with a thickness of about 30 microns. The strips were arranged around the edges of one electrode.
  • the other electrode was placed on top of the first and the whole cell was heated to about 100°C to melt the SURLYN and seal the cell.
  • the cell was then filled with the electrolyte of Example 5 through small holes drilled through the WO, substrates. The fill holes were later sealed with epoxy cement.
  • the open circuit voltage upon exposure to white light was around 880 mV. In the bleached state the white light transmission was about 80%. The transmission upon exposure to white light decreased by about 40%.
  • Shading a part of the TiO during light exposure results in a pattern on the device.
  • the blue coloration is obtained only where the dye- sensitized electrode was directly illuminated, the other parts stayed in the transparent state.
  • the partial coloration can be preserved for more than 24 hours if the cell is stored with open-circuited electrodes.
  • An electrolyte solution was made up containing 0.1 M LiQO 4 and 0.1 M tetrabutylammonium bromide in propylene carbonate with about 1 % A-tert- butylpyridine. This was filled into a cell made up as in Example 9 but using a
  • TYGON gasket instead of SURLYN. This cell developed an open circuit photovoltage of about 230 mV.
  • Spontaneous back reaction, le., bleaching, of the electrochromic material 16 occurs when the light source is no longer available to reach the modulating assembly 10. Since only a small current is required to change the light transmission of the modulating assembly 10, an external battery can be also charged during operation and used to speed up the bleaching process.
  • the electrochromic material 16 When the electrochromic material 16 is in the substantially transparent state, radiation from the sun is substantially transmitted through the first and second plates 26, 28 of the window 24 into the interior of the building. Of course, some amount of the radiation is always reflected and some is absorbed by the first and second plates 26, 28, but, with the electrochromic material 16 in the substantially transparent state, most of the radiation in the near infrared and visible light portions of the spectrum is admitted into the interior of the building.
  • the sun's radiation Inside the building, the sun's radiation, of course, provides light and is eventually absorbed by interior walls, floors, furnishings, and the like, where the electromagnetic radiation is converted to heat energy. In certain ambient weather conditions, the sun's radiation is not desired and often has to be dissipated or removed by ventilation, air conditioning, or the like to maintain the interior of the building at temperatures that are comfortable to humans.
  • the modulating assembly 10 of the present invention is effective in substantially decreasing such undesirable heat gain inside a building from the sun's radiation by a combination of features and without the need for an external power source.
  • the electrochromic material 16 on the inner surface 30 of the first plate 26 of the window 24 changes to a substantially opaque state, thus blocking rather than transmitting the sun's radiation. With most of the sun's radiation blocked in this manner, the sun's radiation does not reach the interior of the building to be absorbed and converted to interior heat.
  • the electrochromic material 16 can be changed back to its substantially transparent state to admit the sun's radiation into the building.
  • the extent of opacity or transparency of the electrochromic material 16 can be varied and set at any desired state between the two limits, so, for example, enough light can be admitted to be able to see through the modulating assembly while minimizing the amount of energy transmitted.
  • the modulating assembly 10 of the present invention can be -used in windows of commercial and institutional buildings, automobile glass, airplane and aerospace applications, sunglasses, and protection of solar concentrators. Therefore, the usefulness of the modulating assembly 10 of the present invention is that the modulating assembly 10 reduces air conditioning costs, glare and UV damage while increasing comfort and thus, productivity of the persons inside the building.
  • the modulating assembly 10 of the present invention is a self- powered system requiring no external electrical wiring. Irradiation sensors are not required. Continuously variable transmission is also available.

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  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)

Abstract

La présente invention concerne un dispositif électrochrome par électrophotochimie. Cet appareil est constitué d'une première électrode (12) transparente et d'une seconde électrode (14) transparente, un écartement étant ménagé entre ces électrodes qui sont parallèles entre elles. La première électrode (12) transparente comporte une liaison galvanique avec la seconde électrode (14) transparente. Un matériau électrochrome (16) est appliqué sur la première électrode (12) transparente, un revêtement semi-conducteur (18) étant appliqué sur la seconde électrode (14) transparente. Une couche d'électrolyte (22) est en contact avec le matériau électrochrome (16) et avec le revêtement semi-conducteur (18). La couche d'électrolyte (22) comporte un couple oxydoréducteur faisant que la lumière incidente provoque l'absorption de la lumière par le revêtement semi-conducteur (18) et que le couple oxydoréducteur s'oxyde, ce qui produit un champ électrique à travers le dispositif et module la transparence effective du dispositif.
PCT/US1997/008773 1996-05-30 1997-05-27 Dispositif electrochrome par electrophotochimie WO1997045767A1 (fr)

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Application Number Priority Date Filing Date Title
AU31409/97A AU3140997A (en) 1996-05-30 1997-05-27 Photoelectrochemical-electrochromic device

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US65572496A 1996-05-30 1996-05-30
US08/655,724 1996-05-30

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WO1997045767A1 true WO1997045767A1 (fr) 1997-12-04
WO1997045767B1 WO1997045767B1 (fr) 1997-12-31

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999005566A1 (fr) * 1997-07-22 1999-02-04 Sustainable Technologies Australia Limited Fenetres intelligentes electrophotochromiques et procedes
WO1999032574A1 (fr) * 1997-12-19 1999-07-01 Bayer Aktiengesellschaft Dispositif electrochrome protege contre les uv
DE19816675A1 (de) * 1998-04-15 1999-10-28 Fraunhofer Ges Forschung Optisches Bauelement
WO2000048040A1 (fr) * 1999-02-12 2000-08-17 Bayer Aktiengesellschaft Dispositif electrochromique renfermant des nanoparticules et des agents absorbant les uv dans la couche de protection
US6266177B1 (en) 1999-11-18 2001-07-24 Donnelly Corporation Electrochromic devices
WO2002010852A1 (fr) * 2000-08-01 2002-02-07 Midwest Research Institute Dispositif photoelectrochimique- electrochrome d'auto-blanchiment
EP1936603A1 (fr) * 2006-12-19 2008-06-25 European Central Bank Procédé de production de cladribine
US9581875B2 (en) 2005-02-23 2017-02-28 Sage Electrochromics, Inc. Electrochromic devices and methods
WO2020253765A1 (fr) * 2019-06-19 2020-12-24 京东方科技集团股份有限公司 Structure d'affichage transparente et fenêtre transparente ayant une fonction d'affichage
CN116449623A (zh) * 2022-01-06 2023-07-18 长春理工大学 一种电光双方式调控变色器件及其制造方法

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5604626A (en) * 1995-02-10 1997-02-18 Donnelly Corporation Photochromic devices

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5604626A (en) * 1995-02-10 1997-02-18 Donnelly Corporation Photochromic devices

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
ELECTROCHEMICA ACTA, Vol. 38, No. 18, 1993, MONK et al., "Electrochromic Display Devices of Tungstic Oxide Containing Vanadium Oxide or Cadmium Sulphide as a Light-Sensitive Layer", pp. 2759-2764. *
SOLAR ENERGY MATERIALS AND SOLAR CELLS, 32, (1994), LAMPERT C.A., "Towards Large-Area Photovoltaic Nanocells: Experiences Learned from Smart Window Technology", pp. 307-321. *

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999005566A1 (fr) * 1997-07-22 1999-02-04 Sustainable Technologies Australia Limited Fenetres intelligentes electrophotochromiques et procedes
US6297900B1 (en) 1997-07-22 2001-10-02 Sustainable Technologies Australia Limited Electrophotochromic smart windows and methods
WO1999032574A1 (fr) * 1997-12-19 1999-07-01 Bayer Aktiengesellschaft Dispositif electrochrome protege contre les uv
AU741615B2 (en) * 1997-12-19 2001-12-06 Bayer Aktiengesellschaft UV protected electrochromic device
US6429960B1 (en) 1998-04-15 2002-08-06 Fraunhofer-Gesellschaft Zur Forderung Der Angewandten Forschung E.V. Optical component
DE19816675A1 (de) * 1998-04-15 1999-10-28 Fraunhofer Ges Forschung Optisches Bauelement
WO2000048040A1 (fr) * 1999-02-12 2000-08-17 Bayer Aktiengesellschaft Dispositif electrochromique renfermant des nanoparticules et des agents absorbant les uv dans la couche de protection
US7190506B1 (en) 1999-02-12 2007-03-13 Bayer Aktiengesellschaft Electrochromic device with nanoparticles and UV-absorbers in the protective coating
US6266177B1 (en) 1999-11-18 2001-07-24 Donnelly Corporation Electrochromic devices
WO2002010852A1 (fr) * 2000-08-01 2002-02-07 Midwest Research Institute Dispositif photoelectrochimique- electrochrome d'auto-blanchiment
US9581875B2 (en) 2005-02-23 2017-02-28 Sage Electrochromics, Inc. Electrochromic devices and methods
US10061174B2 (en) 2005-02-23 2018-08-28 Sage Electrochromics, Inc. Electrochromic devices and methods
US11567383B2 (en) 2005-02-23 2023-01-31 Sage Electrochromics, Inc. Electrochromic devices and methods
EP1936603A1 (fr) * 2006-12-19 2008-06-25 European Central Bank Procédé de production de cladribine
WO2020253765A1 (fr) * 2019-06-19 2020-12-24 京东方科技集团股份有限公司 Structure d'affichage transparente et fenêtre transparente ayant une fonction d'affichage
CN116449623A (zh) * 2022-01-06 2023-07-18 长春理工大学 一种电光双方式调控变色器件及其制造方法

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