Porous layer at least partially transparent to infrared light but reduced in transmittance to visible light

Abstract

The present invention relates to a porous layer that is transparent to at least a portion of the spectrum of infrared light but blocks the passage of a majority of visible light through the layer. Preferably, the porous layer is permeable to a solvent, the solvent comprising water and an organic solvent. Preferably, the porous layer comprises particles, spheres, threads, rods or a porous base layer comprising a multi-layer coating providing Bragg reflection structures. The invention also relates to a device comprising such a porous layer, preferably selected from the group consisting of electrochemical devices, optoelectronic devices, photochromic devices, photochromic devices and displays.

Description

Technical Field

[0001] The present invention relates generally to the field of light selectivity, in particular light transmittance, and more particularly to materials having a relatively high transmittance to at least some infrared light and a relatively low transmittance to visible light. The present invention also relates to a porous layer that is at least partially transparent to infrared light but blocks at least some visible light from passing through the layer. The present invention also relates to a device, in particular an electrical or electronic device and / or a display, comprising the porous layer. Background Art

[0002] Materials that are selectively transmissive to specific wavelengths of electromagnetic radiation have been developed for a variety of applications. In some cases, materials that are more transmissive to infrared light than to visible light have been proposed.

[0003] US2017 / 0123122 discloses a color film that is intended to be used as an infrared-transmitting cover plate to be placed in front of a near-infrared photoelectric conversion device. One purpose of this color film is to reflect a preselected color spectrum to display a predetermined color to an observer. The cover plate includes an interference multilayer, each layer of the stack having a different refractive index from the adjacent layers of the stack. The multilayer achieves light capture of a portion of the visible light because it behaves like an optical waveguide. The layer that is transparent to IR light is continuous and impermeable to water. In certain applications, such as certain electrochemical, photoelectric and / or color-changing devices, it would be advantageous to have a layer that is permeable to water, electrolytes and / or other liquids, depending on the circumstances.

[0004] US2019 / 008217A1 discloses a textile comprising a porous polyolefin, wherein the textile has holes and has a transmittance of at least 40% to infrared radiation with a wavelength of 9.5 μm. The size of the nanopores (about 50nm-1000nm) is designed to scatter visible light to obtain an opaque appearance, but the mid-IR transmittance remains essentially unchanged. The textile of the reference is suitable for clothing, but not for other applications, such as electrochemical, optoelectronic and / or color-changing devices. In some applications, more inert and / or more durable materials are required. In view of the reference, another object of the present invention is to obtain a sharp change in the transmission spectrum within a relatively short wavelength range of about 100nm extending between visible light and IR light. Another object is to provide a material with higher transmittance in the near-infrared region.

[0005] US2021 / 0087116 discloses nanocrystalline ceramic oxide beads that are visibly dark and infrared-transmissive. These beads can be added to basecoat paints, clearcoat paints and automotive films, but in particular to pavement markings and vehicle coatings. The latter films are impermeable to liquids or solvents and, moreover, may have improved light-absorbing properties when combined with paint.

[0006] US2008 / 0316594 discloses a dielectric multilayer film (ZrO2 and SiO2) layer that is transmissive to IR light. These layers can be used in remote controls. As with the other documents mentioned above, these materials are not porous and are not suitable for use in situations where permeability to solvents is required.

[0007] US2019 / 0391307 discloses an optical filter comprising a wavelength selective reflection layer and an absorption layer, which can be used in an optical imaging system. US2012 / 00389990 discloses an optical film similar to the optical film described in US 2019 / 0391307.

[0008] Z. Wu et al. disclosed a thin film Bragg stack exhibiting structural color in "Structural Color in Porous, Superhydrophillic, and Self-Cleaning SiO2 / TiO2 Bragg Stacks", 2007, small, 3(8), 1445-1451.

[0009] It is an object of the present invention to provide a porous layer which is transparent to at least part of the infrared light but is not transparent to at least some but preferably all of the visible light.

[0010] It is an object of the present invention to provide a porous layer which is transmissive to at least part of the infrared light but reflective to at least some but preferably all of the visible light.

[0011] It is an object of the present invention to provide a porous layer which exhibits light transmission and light reflection properties which are minimally dependent on the angle of incidence of the light.

[0012] It is an object of the present invention to provide a porous layer which exhibits diffuse reflection in at least some visible light, but preferably in all visible light.

[0013] It is an object of the present invention to provide a layer which is permeable to solvents and which can be integrated into an electrochemical device, an optoelectronic device, a color-changing device and / or a display or other device.

[0014] The object of the present invention is to provide a material having the above mentioned properties and which can be relatively thin, for example thinner than 500 μm, preferably thinner than 200 μm.

[0015] It is also an object of the invention to provide a layer which is more transparent to IR light than to most visible light and which does not react in the presence of redox-active substances and / or organic solvents and / or water.

[0016] The present invention also aims to provide a light-driven or light-controlled device comprising a photosensitive material (eg, a photosensitive electrode, a photochromic and / or a photoelectrochromic material).

[0017] Further objects and problems to be solved by the present invention will become apparent from the following description of aspects and embodiments of the present invention. Summary of the invention

[0018] In one aspect, the present invention provides a porous layer that reflects and / or absorbs at least some visible light and is transmissive and / or transparent to at least some infrared light.

[0019] In one aspect, the present invention provides a porous layer that exhibits selective permeability to infrared light while preferably having a lower permeability or non-permeability to at least some visible light.

[0020] In one aspect, the present invention provides a porous layer that blocks more photons in the visible spectrum, between 350 nm and 750 nm, from passing through the layer while transmitting more photons in the infrared spectrum, between 751 nm and 1400 nm.

[0021] In another aspect, the present invention provides a porous layer that exhibits selective permeability to light because the porous layer blocks 60% or more of the photons of light having a wavelength within a first continuous range within the visible light spectrum from passing through the layer; and the porous layer is permeable to at least 60% of the photons of light having a wavelength within a second continuous range, wherein the second continuous range is within the infrared (IR) spectrum.

[0022] In another aspect, the present invention provides a porous layer having selective permeability to light because the porous layer blocks 60% or more of photons of light having a wavelength falling within a continuous range of at least 100 nm in the visible spectrum from passing through the layer; and the porous layer is permeable to at least 60% of photons of light having a wavelength falling within a continuous range of at least 5 nm in the infrared (IR) spectrum.

[0023] In yet another aspect, the present invention provides a device comprising a porous layer. Preferably, the device is selected from one or more of the following: a display, a screen, an electrical device, an electronic device, an electrochemical device, a photochromic device, a photoelectrochromic device, an electrochromic device, an electro-optical device, a photoelectrochemical device, a photochemical device, and an optoelectronic device. In an embodiment, the device is a layered device comprising two, three, four or more superimposed layers. In one embodiment, the device is an overall flat device comprising two major opposing surfaces or sides.

[0024] In one aspect, the invention provides a display, preferably a display according to one or more of the aforementioned device categories.

[0025] Other aspects and preferred embodiments of the present invention are defined below and in the appended claims. Other features and advantages of the present invention will be apparent to those skilled in the art from the description of preferred embodiments given below. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A porous layer according to an embodiment of the present invention and its behavior to visible and infrared light impinging on the layer are schematically shown.

[0027] Figure 2 A porous layer according to an embodiment and its permeability with respect to a liquid (eg, an organic solvent) are schematically shown.

[0028] Figure 3A and Figure 3B A porous layer comprising substantially spherical particles according to an embodiment of the present invention and a corresponding enlarged view of a single particle are schematically shown, respectively.

[0029] Figure 4 A porous layer comprising particles substantially in pressed sheet-like form or in the shape of a sheet according to another embodiment is schematically shown.

[0030] Figure 5 A porous layer including a porous base layer coated with multiple layers according to yet another embodiment is schematically shown.

[0031] Fig. 6A FIG. 1 is a schematic diagram of a porous base layer coated with multiple layers according to another embodiment.

[0032] Figure 6B Schematically shows Fig. 6A The layers shown in are obtained.

[0033] Figure 7 A device comprising a porous layer according to an embodiment of the present invention is schematically shown.

[0034] Preferred embodiments of the device of the present invention will be described below to illustrate the present invention, but are not intended to limit the scope of the present invention. DETAILED DESCRIPTION

[0035] The present invention relates to a porous layer that is transparent to at least some infrared (IR) light and blocks at least some visible light from passing through the layer.

[0036] For the purposes of this specification, visible light is light having a wavelength in the range of 350 nm to 750 nm, and infrared IR light is light having a wavelength in the range of 751 nm to 1400 nm.

[0037] Figure 1 The selective permeability and impermeability of the porous layer 100 are schematically shown. The porous layer has two opposing major sides, which are referred to herein as a first side 11 and a second side 12 of the porous layer.

[0038] The porous layer of the present invention can be flexible or rigid. In some embodiments, the porous layer is a film or sheet, preferably, the porous layer is a film or sheet with a substantially constant thickness (± 10% variation, preferably, ± 5% variation) within its operating coverage. For example, the first side and the second side are preferably smooth on a macro scale, but are structured and / or porous on a micro scale and / or a meso scale. The porous layer can be flat and / or the porous layer can extend on a plane, as shown. In other embodiments, the porous layer can extend at least in part with one or more selected from a curved surface, an arcuate surface, a concave surface and / or a convex surface.

[0039] Reference numeral 51 refers to visible light having a particular wavelength, but is also considered to refer to visible light of a different wavelength. Reference numeral 52 is light having the same wavelength as light 51 but reflected or scattered by porous layer 100, including diffuse reflected light (small arrows). Reference numeral 53 is also visible light, and this time light 53 is absorbed by layer 100, as shown by reference numeral 54. The wavelength of light 53 may be different from that of light 51. Alternatively, the wavelength of light 53 is the same, so Figure 1 Different embodiments of the porous layer 100 are shown, one embodiment is to reflect a specific wavelength of visible light, and another embodiment is to absorb the visible light. The present invention covers both possibilities. According to the present invention, the porous layer blocks at least some visible light from passing through the layer. The present invention is preferably not limited to mechanisms that block transmittance, such as reflection and / or absorption of visible light. Therefore, the porous layer is not transparent to at least part of the visible light, or is not completely transparent.

[0040] Arrow 55 represents infrared light, preferably of a specifically defined wavelength. Alternatively, arrow 55 refers to infrared light (751 nm to 1400 nm light, see above). Porous layer 100 is transparent to at least some infrared light 55, as indicated by the arrows exiting porous layer 100 from second side 12 of porous layer 100.

[0041] In some embodiments, the properties of light transmittance (defined characteristics and / or transmittance) outlined above are further defined in the preferred embodiments below, and in most embodiments need not apply to all photons of a particular wavelength and / or all wavelengths of visible light or infrared light, respectively.

[0042] In one embodiment, the porous layer blocks 50% or more of the photons of light in a continuous range of at least 100nm extending in the visible spectrum from passing through the layer. Preferably, the continuous range is a range of at least 150nm, more preferably at least 200nm, even more preferably at least 250nm, and most preferably at least 300nm. The continuous range is preferably completely within the spectrum of visible light. For example, a continuous range of at least 100nm can be visible light included in a wavelength range of 350nm to 450nm, 400nm to 500nm, 450nm to 550nm, 600nm to 700nm, or 700nm to 750nm. For example, a range of at least 150nm can be a range of light including a wavelength of 350nm to 500nm, 400nm to 550nm, 450nm to 600nm, 500nm to 650nm, 550nm to 700nm, or 600nm to 750nm. Of course, other ranges are possible, such as 410 nm to 510 nm as an example range of at least 100 nm, or 430 nm to 580 nm as an example range of at least 150 nm. Furthermore, these minimum ranges do not exclude the possibility that light is blocked from passing through a larger range.

[0043] Preferably, the continuous range (also referred to as the first continuous range) is completely within the wavelength range covered by visible light defined in this specification.

[0044] In addition, in some embodiments, the porous layer does not completely block visible light as defined above. In an embodiment, the porous layer blocks 60% or more of the photons of the defined visible light from passing through, more preferably, the porous layer blocks 70% or more of the photons of the defined visible light from passing through, even more preferably, the porous layer blocks 80% or more of the photons of the defined visible light from passing through, and most preferably, the porous layer blocks 90% or more of the photons of the defined visible light from passing through. These percentages are independently applicable to the visible light range defined above, thereby including various combinations, some of which are described below.

[0045] In an embodiment, the porous layer blocks 60% or more of the photons in the defined continuous range of at least 100 nm from passing through the layer. Preferably, 70% or more of the photons in the at least 100 nm range are blocked from passing through, more preferably, 80% of the photons in the at least 100 nm range are blocked from passing through, and most preferably, 90% of the photons in the at least 100 nm range are blocked from passing through.

[0046] In an embodiment, the porous layer blocks 60% or more of the photons in the defined continuous range of at least 150 nm from passing through the layer. Preferably, 70% or more of the photons in the continuous range of at least 150 nm are blocked from passing through, more preferably, 80% of the photons in the continuous range of at least 150 nm are blocked from passing through, and most preferably, 90% of the photons in the continuous range of at least 150 nm are blocked from passing through.

[0047] In an embodiment, the porous layer blocks 60% or more of the photons in the defined continuous range of at least 200 nm from passing through the layer. Preferably, 70% or more of the photons in the continuous range of at least 200 nm are blocked from passing through, more preferably, 80% of the photons in the continuous range of at least 200 nm are blocked from passing through, and most preferably, 90% of the photons in the continuous range of at least 200 nm are blocked from passing through.

[0048] In some embodiments, the porous layer may include one or more regions and / or one or more gaps, wherein visible light can pass through the layer at a percentage higher than the above values, for example, more than 50%, or more than 60%. For example, the porous layer may exhibit an indicated lack of transmission for two separate wavelengths and / or wavelength ranges as defined above. Thus, the porous layer blocks more than 60% of photons with wavelengths within range (a) and photons with wavelengths within range (b) from passing through the layer, but may be more transmissive for photons with wavelengths outside range (a) and range (b), for example, photons between ranges (a) and (b). In this case, as described elsewhere in this specification, the device of the present invention preferably includes a filter and / or reflector for preventing light outside range (a) and range (b) from entering the device.

[0049] For the purposes of this specification, infrared light has been defined above as all light having a wavelength comprised within the range of 751 nm to 1400 nm. Light having a wavelength greater than 1400 nm is not considered within the scope of the present invention, which means that the present invention does not impose any properties or limitations on the porous layer regarding the transmittance of light having a wavelength greater than 1400 nm.

[0050] In a preferred embodiment, the present invention is particularly concerned with IR light contained in the range of 751 nm to 1200 nm. According to this particular embodiment, light with a wavelength of 1201 nm to 1400 nm is irrelevant to the features of the present invention (e.g., features related to transmittance), which means that the present invention does not impose any properties or restrictions on the transmittance of light with a wavelength greater than 1200 nm on the porous layer. In addition, according to this embodiment, the ranges given in column D of Tables 1 and 2, as well as the ranges of IR light defined for other embodiments disclosed in this specification (e.g., 5 nm, 10 nm, 15 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, and 100 nm ranges or percentages of transmittance to photons) are, for example, fully selected as part of the entire range of 751 nm to 1200 nm hereinafter.

[0051] In an embodiment, the porous layer is transparent to at least 60% of the photons of light having a wavelength falling within a continuous range of at least 5 nm extending within the infrared (IR) spectrum. Preferably, the continuous range is a range of at least 10 nm, more preferably a range of at least 15 nm, even more preferably a range of at least 30 nm, and most preferably a range of at least 40 nm, such as at least 50 nm, at least 60 nm, 70 nm, 80 nm, and most preferably at least 100 nm. The continuous range is preferably completely within the spectrum of IR light as defined in the present specification. For example, the continuous range of 5 nm can be IR light having a wavelength of 751 nm to 756 nm, 770 nm to 775 nm, 780 nm to 785 nm, 790 nm to 795 nm, or for example 795 nm to 800 nm. The range of at least 10 nm can be a range including, for example, light with wavelengths of 770 nm to 780 nm, 780 nm to 790 nm, 790 nm to 800 nm, 800 nm to 810 nm, 810 nm to 820 nm, 820 nm to 830 nm, 830 nm to 840 nm, 840 nm to 850 nm, 850 nm to 860 nm, 860 nm to 870 nm, 880 nm to 880 nm, … , 1190 nm to 1200 nm, … , 1390 nm to 1400 nm.

[0052] The range of at least 15 nm may be a range including, for example, light having wavelengths of 751 nm to 766 nm, 760 nm to 775 nm, 770 nm to 785 nm, 785 nm to 800 nm, 800 nm to 815 nm, ... 1175 nm to 1190 nm.

[0053] Preferably, said continuous range (also referred to as second continuous range) lies completely within the wavelength range covered by IR light as defined herein.

[0054] Furthermore, in some embodiments, the porous layer is not completely transparent to the IR light as defined above. In embodiments, the porous layer is transparent such that 60% or more of the photons of the IR light as defined pass through, more preferably 60% or more of the photons pass through, even more preferably 70% or more of the photons pass through, and most preferably 80% or more of the photons pass through. These percentages apply independently to the range of IR light as defined above.

[0055] Some embodiments regarding the transmittance or transmissivity within the continuous range of IR light defined in this specification are provided below.

[0056] In an embodiment, the porous layer is transparent to 60% or more of the photons in the defined continuous range of at least 5 nm. Preferably, 70% or more of the photons in the at least 5 nm range can pass through, more preferably 80% or more of the photons can pass through, and most preferably 90% or more of the photons can pass through.

[0057] In an embodiment, the porous layer is transparent to 60% or more of the photons in the defined continuous range of at least 10 nm. Preferably, 70% or more of the photons in the at least 10 nm range can pass through, more preferably 80% or more of the photons can pass through, and most preferably 90% or more of the photons can pass through.

[0058] In an embodiment, the porous layer is transparent to 60% or more of the photons in the defined continuous range of at least 15 nm. Preferably, 70% or more of the photons in the at least 15 nm range can pass through, more preferably 80% or more of the photons can pass through, and most preferably 90% or more of the photons can pass through.

[0059] In an embodiment, the porous layer is transparent to 60% or more of the photons in the defined continuous range of at least 30 nm. Preferably, 70% or more of the photons in the at least 30 nm range can pass through, more preferably 80% or more of the photons can pass through, and most preferably 90% or more of the photons can pass through.

[0060] In an embodiment, the porous layer is transparent to 60% or more of the photons in a continuous range of at least 50 nm defined. Preferably, 70% or more of the photons in the 50 nm range can pass through, more preferably 80% or more of the photons can pass through, and most preferably 90% or more of the photons can pass through.

[0061] In an embodiment, the porous layer is transparent to 60% or more of the photons in the defined continuous range of at least 70 nm. Preferably, 70% or more of the photons in the at least 70 nm range can pass through, more preferably 80% or more of the photons can pass through, and most preferably 90% or more of the photons can pass through.

[0062] The present invention covers various combinations of ranges through which visible light (VIS) is substantially blocked and through which IR light can pass. For example, a VIS range of at least 100 nm can be combined with any one of the IR ranges selected from at least 5 nm, 10 nm, 15 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm and 100 nm.

[0063] The VIS range of at least 150 nm may be combined with any one IR range selected from the group consisting of at least 5 nm, 10 nm, 15 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm and 100 nm.

[0064] The VIS range of at least 200 nm may be combined with any one IR range selected from the group consisting of at least 5 nm, 10 nm, 15 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm and 100 nm.

[0065] The VIS range of at least 250 nm may be combined with any one IR range selected from the group consisting of at least 5 nm, 10 nm, 15 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm and 100 nm.

[0066] The VIS range of at least 300 nm may be combined with any one IR range selected from the group consisting of at least 5 nm, 10 nm, 15 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm and 100 nm.

[0067] Furthermore, it is also possible to combine the defined percentage of photons in the visible range that are prevented from passing through with the percentage of photons in the IR range that can pass through the porous layer, in particular with the specified range.

[0068] Tables 1 and 2 below further detail some embodiments encompassed by the present invention. Column A indicates a specific embodiment (embodiment number). Column B is the nanometer width of the smallest range in the visible spectrum as defined herein, where a certain minimum percentage of photons indicated in column C are prevented from passing through the porous layer. Column D is the nanometer width of the smallest range in the IR spectrum as defined herein, where a certain minimum percentage of photons indicated in column E can pass through the porous layer. Table 1 covers visible light ranges of at least 100nm, 150nm, and 200nm, where the indicated minimum percentage of light will not pass through the layer, and Table 2 covers visible light ranges of at least 250nm, 300nm, and 350nm.

[0069] In an embodiment, the porous layer of the present invention exhibits a relatively sharp change in transmittance over a relatively short wavelength range at the transition between visible light and IR light. In an embodiment, at the transition between visible light and IR light, the change in transmittance is at least 40% of the photons, preferably at least 50% of the photons, within a range of no more than 200nm. Preferably, the range is even shorter, such as 150nm or less, or even 100nm or less. The transition is considered to cover a wavelength of 650nm to 850nm. For example, there is at least a 40% change in transmittance within a range of 650nm to 750nm or within a range of 700nm to 800nm. For example, only 30% of the photons with a wavelength of about 650nm pass through the porous layer, while 80% of the photons with a wavelength of 750nm pass through the porous layer. In this example, there is a 50% change in transmittance within a range of 100nm or less. Therefore, the change in transmittance in percentage is preferably relatively abrupt within a relatively short range of light (e.g., 100nm).

[0070] The above-mentioned indicators (in particular percentages) relating to the transmittance and / or reduced transmittance, if applicable, preferably relate to light perpendicular to the entire plane in which the layer 100 is arranged. Figure 1 In the embodiment, the entire plane corresponds to the first side or surface 11 of the layer 100. The incident angle of this light is 0°. Preferably, the indicated values ​​also apply to light incident on the porous layer at an incident angle greater than (or less than) 0°, for example Figure 1 The above values ​​are preferably also applicable to light with an incident light angle of ±15°, more preferably ±25°, even more preferably ±30° and most preferably ±40° relative to the normal. Even more preferably, the above values ​​are applicable to all or almost all incident light with a wavelength within the corresponding wavelength range of visible light or IR light, respectively.

[0071] Surprisingly, the present invention provides a porous layer that exhibits minimal dependence of light transmission and reflection properties on the angle of incident light. For example, the difference in transmittance is less than 50% when the angle of incident light varies by ±25°.

[0072] The transmittance of visible light and IR light having a specific wavelength or extending to a certain wavelength range can be determined using a light source and a light intensity sensor, such that a reference value is obtained by emitting light and determining a signal from the sensor for obtaining a reference value, and once the reference value is obtained, a porous layer is placed in the light path between the light source and the sensor to obtain a measurement signal, which can be compared with the reference value to determine the transmittance.

[0073] In a preferred experimental setup, a light source, an optical fiber for directing light to the sample (or sample holder) and from the sample holder to the sensor, a collimating lens for providing a non-dispersive light beam, a sample holder and a spectrometer as a sensor are used. The measurement type is preferably used for straight-through transmission (RIT), and the incident light angle of the light is preferably 0 or close to 0 (perpendicular to the sample, in particular perpendicular to the surface 11). In order to measure the dependence of the transmittance on the incident light angle, an appropriate holder setting is required to fix the angle between the incident light and the plane of the sample surface. For sample layers that exhibit scattering, an integrating sphere should be used to collect the total transmitted light before forwarding the signal to the light sensor. For more detailed information, Spectrophotometry-Accurate Measurement of Optical Properties of Materials (ISBN: 978-0-12-386022-4) can be used.

[0074] The percentage of photons of a given wavelength that are prevented from passing through the porous layer corresponds to a corresponding reduction in the percentage of light intensity. For example, if the measured light intensity passing through the porous layer is reduced by 50%, this is equivalent to preventing 50% of the photons from passing through the layer.

[0075] In an embodiment, the porous layer is porous. The porosity is preferably such that the layer does not completely block liquids, in particular solvents. Thus, such liquids can pass through the porous layer, for example by diffusion. Preferably, the porous layer is permeable.

[0076] In an embodiment, the permeability of the porous membrane is greater than 0 Darcy, preferably greater than 0.25 Darcy, and even more preferably greater than 0.5 Darcy. Most preferably, the permeability is greater than 0.75 Darcy and even greater than 1 Darcy. "Darcy" is a practical unit of permeability. If a pressure difference of 1 atm will cause a fluid with a viscosity of 1 cP to flow at a pressure of 1 cm 3 / sec flows through a cube with a side length of 1 cm, then the permeability of the porous material is equal to 1 Darcy.

[0077] In a preferred embodiment, the porous layer is permeable to one or more solvents, in particular organic solvents and / or water. Exemplary solvents are selected from one, two, more or all of the following: water, propylene carbonate, ethylene carbonate, tetrahydrofuran, dioxane, dimethyl sulfoxide, dimethylformamide, acetonitrile, sulfolane and gamma-butyrolactone. Preferably, the solvent is liquid at room temperature (25° C.) and the permeability is at least suitable for room temperature (RT).

[0078] Figure 2 The permeability due to the porosity of layer 100 is shown. Solvent molecules 2-methylpropionaldehyde (isobutyraldehyde) 63 and propylene carbonate 64 are shown passing through layer 100, preferably more or less unhindered, as shown by arrows 61 and 62, respectively. Preferably, liquid or solvent molecules with a molecular weight of up to 600, more preferably up to 650, even more preferably up to 700, and most preferably up to 800 can pass through the porous layer.

[0079] In an embodiment, the permeability is due to the pores provided in the porous layer, which preferably have an opening size with an average diameter of 1 nm to 50 μm, most preferably 5 nm to 10 μm, and even more preferably 20 nm to 1 μm. Preferably, the porous layer comprises pores connecting two opposite sides 11 and 12 of the porous layer. Preferably, the pores enable communication between areas exposed to the two opposite main sides 11, 21 of the porous layer.

[0080] The thickness of the porous layer is preferably 50 nm to 1 mm, preferably 50 nm to 600 μm, more preferably 70 nm to 500 μm, even more preferably 90 nm to 400 μm. In an embodiment, the thickness is 50 nm to 500 μm.

[0081] In a preferred embodiment, the thickness of the porous layer is 500nm to 500μm, preferably 600nm to 400μm, more preferably 700nm to 350μm, and most preferably 800nm ​​to 300μm. Even more preferably, the thickness of the porous layer is 1μm to 250μm, preferably 2μm to 100μm, and most preferably 5μm to 50μm.

[0082] As mentioned elsewhere in this specification, the thickness is preferably a substantially constant thickness (variation of ±20%, preferably ±10%) within the thickness range indicated herein, preferably when taking into account the functional area of ​​the porous layer.

[0083] According to an embodiment, the above-mentioned characteristics related to selective permeability can be provided by the presence of multiple layers, preferably multiple layers capable of achieving interference, preferably constructive interference and / or Bragg reflector properties. The interference is preferably due to the Bragg reflector properties of the porous layer, and in particular the Bragg reflector properties of the multiple layers contained in the porous layer.

[0084] In a preferred embodiment, the multilayer provides one or more selected from a Bragg reflector, a distributed Bragg reflector, a Bragg mirror and a dielectric mirror. The term "Bragg reflector" is generally used to refer to any of the above. Such structures can achieve selective reflection for certain wavelengths or wavelength ranges.

[0085] Preferably, the properties of the Bragg reflector are particularly suitable for defined visible light, whereas the porous layer exhibits no or only to a lesser extent Bragg reflector properties for defined IR light.

[0086] On the other hand, the defined features related to porosity preferably result from the fact that the porous layer is based on particles and / or a porous substrate, wherein said porous substrate and / or said particles constitute said multiple layers providing the selective permeation described herein.

[0087] In an embodiment, the porous layer of the present invention comprises one or two selected from the following: particles 20 , preferably particles 20 are microparticles and / or nanoparticles, more preferably particles 20 are sintered microparticles and / or nanoparticles; and a porous base layer 30 and a coating layer 28 .

[0088] Figure 3A A porous layer 101 is shown, which comprises particles 20 and preferably consists essentially of particles 20. Several, many, most and preferably all of the particles of the porous layer 101 are multilayer particles and / or comprise multiple layers 28.

[0089] like Figure 3B As shown more clearly in FIG. 2 , the particle 20 includes a core 31 and additional layers 32, 33, 34, 35, 36 formed by stacking around the core. In the embodiment shown, the core 31 is considered as part of the multiple layers, but in other embodiments, the core 31 can also be considered as separate from the multiple layers 28.

[0090] The particles 20 constituting the multilayer 28 preferably exhibit interference, preferably constructive interference, in particular interference with visible light as defined elsewhere in this specification. Preferably, the particles exhibit Bragg reflector properties. Figure 3AAs shown, incident light 56 ​​includes visible light 51 and IR light 55, as defined elsewhere in this specification. Visible light 51 is absorbed, scattered and / or reflected as light 52, preferably absorbed, scattered and / or reflected by multiple layers acting as Bragg reflectors. IR light 55 passes through porous layer 101.

[0091] The multilayer 28 preferably includes layers 31 to 36 that provide interference, preferably functioning as Bragg reflectors.

[0092] Preferably, the first layer 31 (or core) comprises a different material than the second layer 32, the second layer 32 being the neighboring layer that is closest or proximate to the first layer 31 toward the interior of the particle. It can be said that the first layer 31 comprises or consists essentially of a first material, and the second layer 32 comprises or consists essentially of a second material, wherein the first material and the second material are different. Preferably, the first material and the second material have different refractive indices. For example, the first material and the second material have different elemental compositions and / or different chemical structures.

[0093] Preferably, a third layer 33 is provided on the outer side of the second layer 32. The second layer 32 is the inner layer closest to the third layer. The third layer 33 preferably includes a material different from the second material included in the second layer. In an embodiment, the third layer may include the same material as the first layer, or further include a third material different from both the first material and the second material.

[0094] The particle 20 preferably includes two or more layers, preferably includes three, four, five, six or more layers. In an embodiment, the multilayer 28 preferably includes four or more layers, most preferably includes five or more layers.

[0095] Typically, it is preferred to provide an additional layer numbered y=x+1 to have a nearest internal adjacent layer numbered x comprising a material having a refractive index different from the refractive index of the material of the additional layer y. For example, the fifth layer (y=5) comprises a material different from the material of the fourth layer (x=4). Preferably, x is an integer that increases one by one starting from 1 to correspond to the numbering of a particular layer of the multilayer. For example, the core will be the first layer (x=1). Y represents any layer that has layer x as its nearest internal adjacent layer. Z can be the total number of layers in the multilayer, so that, for example, z can be 20, 15, 10, 8, 7, 6, 5, 4.

[0096] In the case of compressed flaked particles (see below), the first layer may not be the core, but it may be best described as the bottom layer (or top layer). In this particular case, either of the two outermost layers (bottom layer or top layer) may be considered the first layer, and the outermost layer on the opposite side may be considered the z layer.

[0097] In principle, therefore, the particles can essentially consist of two different first and second materials, which are deposited alternately on top of each other to form the multilayer. Figure 3A and Figure 3B The principle shown in .

[0098] In other words, the porous layer preferably comprises particles 20, each of which comprises a plurality of superimposed layers 31 to 36, wherein a given layer 33 of the particle has one, two or possibly more nearest neighboring layers 31, 32, and wherein the material of the given layer 33 has a refractive index different from the refractive index of at least one and possibly more further materials of the one, two or more nearest neighboring layers 31, 32. In the case of two adjacent or directly adjacent layers (in the case of an inner layer, for example Figure 3B In the case of layers 32 to 35 in the multilayer, two directly adjacent layers may comprise the same material or different materials. If they comprise different materials, this means that the multilayer comprises at least three different materials. Generally, since the multilayer can in principle be realized with two different materials (e.g. SiO2 and TiO2), it is better to use three or more materials in this case for reasons of convenience and / or simplicity.

[0099] Preferably, the layers in the multilayer 28 may be nanolayers, sublayers and / or individual layers 31 to 36. If a core is present, the core may not be a nanolayer, sublayer and / or sublayer, but is still considered a layer. The layers preferably include and / or consist of materials with different refractive indices, in particular consist of at least two different materials.

[0100] The thickness of the layers other than the core 31 may range from a few nanometers to a few micrometers. In an embodiment, preferably the thickness of the layers other than the core is in the range of 10 nm to 1 μm, preferably 20 nm to 200 nm, more preferably 30 nm to 100 nm. These thicknesses preferably refer to the maximum thickness of the layers, since the layers may include areas where they are thinner. If a core 31 is present, the above values ​​preferably apply to the diameter of the core.

[0101] In an embodiment, the multilayer 28 comprises and / or consists essentially of 2 to 50 layers, preferably 4 to 15 layers, even more preferably 5 to 10 layers. If the particles are in the form of Figure 3A and Figure 3BThe core-shell structure shown is provided, then these numbers preferably include the inner core. The layers in the multilayer can also be called sublayers, individual layers or also nanolayers. They are preferably separate layers. Preferably, the individual layers of the multilayer at least partially overlap with one or two adjacent layers. Preferably, the individual layers overlap with one or two adjacent layers over most of their area.

[0102] Preferably, each layer is in contact with its inner nearest or adjacent neighbor. There may be a single contact region, or a given layer (eg layer number y=x+1) may be deposited entirely onto an inner, adjacent or underlying adjacent neighbor (eg layer number x).

[0103] The material having the desired properties and being used for preparing the porous layer can be selected from a large number of different materials. The usable material is preferably stable under the specific conditions of using the porous layer. For example, the material is preferably stable when used in an electrolyte and / or when subjected to a thermal treatment (e.g., sintering and / or annealing). Preferably, the material does not absorb much light, or absorbs light with a designed specific wavelength or wavelength range in the visible spectrum, depending on the application requirements. Preferably, the material is solid at room temperature (RT), more preferably solid in a temperature range of 20°C to 150°C, more preferably solid in a temperature range of 15°C to 250°C, most preferably solid in a temperature range of 0°C to 450°, and even solid in a temperature range of up to 600°C.

[0104] In an embodiment, the materials (the first material, the second material, and if applicable, the third material and further materials) are selected from oxides, sulfides, fluorides, nitrides, arsenides, selenides, bromides, chlorides and iodides, and organic materials, preferably polymers.

[0105] In an embodiment, the oxide, sulfide, fluoride, nitride, arsenide, selenide, bromide, chloride and / or iodide material is selected from alkali metals, alkaline earth metals, transition metals, post-transition metals, metalloids, and lanthanide oxides, sulfides, fluorides, nitrides, arsenides, selenides, bromides, chlorides and / or iodides, and combinations of the oxides, sulfides, fluorides, nitrides, arsenides, selenides, bromides, chlorides and / or iodides. Preferably, the material comprises one of these materials and / or one or more polymers and / or is substantially composed of one of these materials and / or one or more polymers.

[0106] In an embodiment, the material is selected from oxides, sulfides, fluorides, nitrides, arsenides, selenides, bromides, chlorides and / or iodides of Ti, Si, Mg, Ta, Zn, Al, Ge, Hf, Mo, W, Zr, Ca, Ba, Li, Sn, Cd, Pb, Ga, In, B, and / or organic polymers.

[0107] In an embodiment, the material is selected from oxides, sulfides, fluorides and nitride materials of Ti, Si, Mg, Ta, Zn, Al, Ge, Hf, Mo, W, Zr, Ca, Ba, Li, Sn, Cd, Pb, Ga, In, B, and / or organic polymers.

[0108] In an embodiment, the material is selected from oxide materials of Ti, Si, Mg, Ta, Zn, Al, Ge, Hf, Mo, W, Zr, Ca, Ba, Li, Sn, Cd, Pb, Ga, In, B. In another embodiment, the material is selected from sulfide materials of Ti, Si, Mg, Ta, Zn, Al, Ge, Hf, Mo, W, Zr, Ca, Ba, Li, Sn, Cd, Pb, Ga, In, B. In another embodiment, the material is selected from fluoride materials of Ti, Si, Mg, Ta, Zn, Al, Ge, Hf, Mo, W, Zr, Ca, Ba, Li, Sn, Cd, Pb, Ga, In, B. In yet another embodiment, the material is selected from nitride materials of Ti, Si, Mg, Ta, Zn, Al, Ge, Hf, Mo, W, Zr, Ca, Ba, Li, Sn, Cd, Pb, Ga, In, B.

[0109] In an embodiment, the material is selected from TiO2, SiO2, MgF2, Ta2O5, ZnS, Al2O3, GeO2, HfO2, MgO, ZnO, MoO3, WO3, ZrO2, CaF2, MgF2, BaF2, LiF, ZnS, SnS, CdS, PbS, MoS2, GaAs, AlAs, Si3N4, InN, GaN, AlN, TiN, BN and a polymer.

[0110] The inorganic material may be a crystalline material.

[0111] In an embodiment, one or more of the materials may be or include a metal. This preferably applies if the particles or the porous substrate are arranged to exhibit a colour. This may also apply to only part of the particles.

[0112] In order to obtain Figure 3A and Figure 3BThe type of substantially spherical particles disclosed in can follow a modified version of the procedure disclosed by Suim Son et al. in "Designed synthesis of SiO2 / TiO2 core / shell structure as light scattering material for highly efficient dye-sensitized solar cells", ACS Appl. Mater Interfaces, 2013, 5, 11, 4815-4820. The article discloses core-shell particles in which the TiO2 shell is deposited on the SiO2 core. The procedure can be modified by depositing an additional SiO2 layer on top of the TiO2 layer and then depositing an additional TiO2 layer to obtain four layers including the core. The sequence of depositing alternating layers can be further repeated to obtain particles with any desired number of layers, for example 4 to 20 layers.

[0113] Another procedure for obtaining substantially spherical particles comprising a multilayer structure is a modified version of the procedure disclosed by Shunxing Li et al. in "Synthesis of the double-shell anatase-rutile TiO2 hollow spheres with enhanced photocatalytic activity", Nanoscale, 2013, 5, 12150. In this article, the authors produced SiO2-TiO2-SiO2-TiO2 particles with an average size (diameter) of about 300 nm. In this publication, the SiO2 layer is subsequently removed by etching to obtain hollow spheres, which may not be necessary for the purpose of this description. For the purpose of the present invention, it is contemplated that SiO2-TiO2-SiO2 (-TiO2-SiO2) K Particles, wherein K is an integer from 1 to 10; or SiO2-TiO2 (-SiO2-TiO2) can be envisioned L The particles, wherein L is an integer of 1 to 10, preferably 2 to 10.

[0114] Figure 3A and Figure 3BThe substantially spherical particles present in the porous layer 101 are shown. The present invention has no limitation on the form of the particles, and particles in the form of tubes, rods, sheets (e.g., nanosheets), columns (e.g., nanocolumns), pressed sheets, pressed sheets, non-spherical particles, and other forms may be used. Figure 4 In the embodiment of the present invention, the porous layer 102 comprises pressed flake particles 20.2, which comprise and / or consist of multiple layers 28.2. Pressed flake particles can be obtained by depositing a flat and continuous multilayer structure (in particular an interference multilayer structure, such as disclosed in US2017 / 0123122), and then grinding, milling or otherwise reducing it from the flat and continuous multilayer structure to particles, thereby obtaining a particle composition. Figure 3A As described, incident light 56 ​​may include visible light 51 that is blocked from passing through porous layer 102 by particles 20.2 and reflected as reflected visible light 52, or is otherwise blocked from passing through porous layer 102, such as by being absorbed in the porous layer. In contrast, infrared light 55 is substantially unaffected by multilayer structure 28.2 of pressed flake particles and can pass through the porous layer.

[0115] The porous layer according to the invention can be formed by depositing a film comprising the particles 20 or 20.2, wherein the film may also contain a binder and a suitable solvent for facilitating film deposition. The thickness of the deposited film is preferably adjusted so that a porous substrate having the desired thickness and light transmission properties / selectivity is finally obtained. The deposited film can be exposed to a heat treatment, in particular annealing or sintering, to remove the solvent, optionally burn the binder and obtain a porous layer essentially formed by annealed particles. The annealing temperature and time are preferably selected according to the physical properties of the particles.

[0116] In a preferred embodiment, the particles forming the porous layer 100 do not form a single layer of particles. Preferably, the particles are not all arranged on a smooth and / or flat surface, thereby forming particles arranged side by side. Figure 3A As shown, the particles are preferably arranged in the porous layers 100, 101 so as to be one or more selected from one another on top of, superimposed on, overlapped and / or arranged in a particle mixture extending in all three dimensions of space, preferably also extending along a direction perpendicular to the two opposite main surfaces 11, 12 of the porous layer. Therefore, the thickness of the entire porous layer 101 preferably exceeds the diameter of a single particle contained in the porous layer, or the porous layer is formed by a single particle contained in the porous layer. The thickness of the porous layer is preferably determined along the vertical axis 50 of the porous layer, such as Figure 3AAs shown, the thickness of the porous layer corresponds to the shortest distance connecting the two opposite main surfaces 11 and 12 of the porous layer. The axis 50 is preferably perpendicular to the upper surface 11 and / or the plane or surface in which the porous layer extends. The porous layer preferably comprises particles at least partially placed on other particles and / or supported by other particles, so that the thickness of the porous layer is increased due to the packing and / or accumulation of particles within the porous layer, so that the particles extend in all three dimensions mentioned above.

[0117] Figure 5 and Fig. 6A A porous layer 103, 104 is disclosed, the porous layer comprising a coated porous base layer 30. According to this embodiment, according to Figure 6B , firstly a porous substrate 30 is provided and then suitable layers 31 to 35 are deposited one after another directly onto the porous substrate 30. The layers thus deposited preferably form a coating which forms a plurality of layers 28.3 which are preferably deposited onto the porous substrate. The resulting porous layers 103, 104 preferably retain at least some of the porosity of the original porous substrate 30 and, due to the plurality of layers, exhibit the diffraction properties required to prevent at least some visible light (preferably at least some visible light as defined herein) from passing through the layer. This is due to Figure 5 The arrow in the figure shows that it has Figure 3A and Figure 4 The same meaning in .

[0118] It is worth noting that the properties of the porous layers 103, 104, the layers and the multiple layers, in particular the thickness and the number of the layers, are the same as described above for the substantially spherical particles. Like the particles 20, the porous base layer 30 can also be considered as the first layer of the multiple layers, in particular for the purpose of the total number of layers (z) defined in this specification.

[0119] Having discussed various possibilities for providing the multilayer 28, 28.2, 28.3 as part of the porous layer of the present invention, it should be noted that the number of individual layers in the multilayer required to achieve the desired transmission effect may depend on the form or type of particles 20, 20.2 and whether a porous substrate 30 is used. In the case of substantially spherical particles, two individual layers with different materials in addition to the core may be sufficient, so that the multilayer may consist of only two layers, but of course may include more layers, such as 2 to 50 layers. In the case of pressed flake particles, three individual layers may be sufficient, so that the multilayer 28.2 may include three or more layers, such as 3 to 50 layers. In the case of a porous substrate 30, the multilayer 28.3 has four or more layers, such as 4 to 50 individual layers. In principle, there is no specific upper limit for the number of layers in the multilayer, but in order to reduce manufacturing costs and / or complexity, the multilayer preferably includes no more than 50 individual layers, preferably no more than 20 individual layers, more preferably no more than 15 individual layers, and most preferably no more than 10 individual layers.

[0120] According to the invention, the Bragg reflector properties provided by the particles or porous layer have the following advantages: the transmission / reflection spectra are less dependent on the light incidence / observation angle. Figure 3B In the embodiment, the Bragg reflector multilayers form a concentric circle structure in cross section, so light with different incident angles will be affected equally by the Bragg reflector multilayers. Figure 4 The flake-like particles in the porous film have randomly distributed flake-like orientations, so incident light will be collectively affected by a group of randomly distributed flake-like particles. Therefore, the transmission / reflection characteristics of the porous film are less dependent on the incident light angle.

[0121] Another advantage of using spherical or non-spherical particles or porous layers to provide a Bragg reflector is that it allows the effect of a Bragg reflector to be achieved in a more cost-effective manner. Typically, the reflectivity and wavelength selectivity of a Bragg reflector depend to a large extent on the number of layers. The more layers, the more pronounced the effect. Typically, depositing multilayer thin films is time consuming. By using a particle-based Bragg reflector method according to a preferred embodiment of the present invention, Bragg reflector characteristics can be achieved with a smaller number of layers. Since the final porous layer preferably includes overlapping particles, the incident light actually "sees" more layers than a single particle. Therefore, some embodiments of the present invention reduce the time and process for depositing a multilayer thin film used as a Bragg reflector.

[0122] Another significant feature of the present invention compared to conventional Bragg reflectors is the diffuse reflective property. Prior art Bragg reflectors typically have a smooth surface so that the reflection of light is similar in principle to a specular reflector, meaning that the angle of incident light is equal to the angle of reflected light. In some preferred embodiments, the present invention creates a non-smooth / scattering surface at the micrometer and / or nanometer scale, thereby providing a diffuse reflective surface, preferably with a white and / or clear appearance.

[0123] Typical prior art Bragg reflectors provide the function of wavelength selective reflection. In the context of the present invention, the Bragg reflector achieves at least partial blocking of visible light. If it is necessary to block visible light by absorption, organic dyes or visible non-transparent inorganic particles can be dispersed in the porous layers 101, 102, 103 and 104, or arranged above or below the Bragg reflector particles 20 and 20.2. Colored particles or organic molecules can also be embedded in the porous base layer 30. The optional presence of colored particles allows the visible light blocking properties of the porous layer to be adjusted or supplemented, so that it can include a variety of different mechanisms that prevent visible light from passing through the porous layer, such as Bragg reflection and light absorption.

[0124] An alternative to different particles could be to build up multiple layers of Bragg reflector particles using materials that absorb in the visible region. In this case, the use of metals in the multilayer structure could be considered.

[0125] In an embodiment, the porous layer is diffuse and / or reflective to incident visible light, thereby providing a clear, bright, white and / or whitish overall appearance. Preferably, the porous layer is diffuse and / or reflective to at least some but preferably all visible light. The clear, bright, white and / or whitish appearance is advantageous, for example, in display applications, where the appearance of the colored layer can help to display information and / or the background of an image.

[0126] In other embodiments, the layer may also appear overall colored, exhibiting a unique color or a mixture of colors, as some visible light may be absorbed by the layer. As described above, the color may originate from the particles themselves, separate colored particles, or dyes added to the porous layer, such as dye molecules adsorbed on the porous layer.

[0127] In some aspects and embodiments, the present invention provides a device comprising a porous layer. The device can be selected from a display, a screen, an electronic device, an electrical device, an electrochemical device, a photochemical device, a photoelectrochemical device, an optoelectronic device, an electrochromic device, a color-changing device (e.g., a photochromic device and a photoelectrochromic device), and devices belonging to two or more of the above device categories.

[0128] For example, the device may be a display based on an electrochromic device architecture. In addition, if the display uses electricity to operate, the display may be an electronic device.

[0129] In a preferred embodiment, the device is a layered device, preferably comprising two or more layers, which are preferably arranged in an overlapping manner.

[0130] In an embodiment, the device comprises a solvent. Preferably, the porous layer is disposed in said solvent. The solvent may be part of a layer of the layered device, or may be considered as a layer of its own.

[0131] Figure 7 An embodiment of an electrochemical device 200 is shown comprising a first main side 91 and a second main side 92. Preferably, the device comprises a front electrode 95 and a photosensitive back electrode 96. In the embodiment shown, the front electrode is closer to the first side and the back electrode is closer to the second side.

[0132] In an embodiment, the device of the present invention comprises a photosensitive electrode 96. The photosensitive electrode preferably comprises a photosensitive material. In an embodiment, the photosensitive electrode comprises a photoconductor and / or a photodiode.

[0133] A medium 90 is provided, and preferably, the medium 90 is held between the two electrodes. In addition, a porous layer 100 is provided between the electrodes, and the porous layer 100 is in contact with a solvent. In an embodiment, the solvent includes a redox substance, which can undergo a redox reaction according to a potential established between the electrodes.

[0134] Preferably, the porous layer is immersed in the medium 90 and / or surrounded by the medium 90. In an embodiment, the medium 90 includes one or both selected from a solvent and an electrolyte. Preferably, the medium 90 is a liquid medium or a gel-like medium.

[0135] In an embodiment, the photosensitive electrode 96 can be activated, for example turned on or off, by illumination. In order to prevent ambient visible light from reaching and / or acting on the photosensitive electrode, a porous layer 100 is provided. Due to the transmittance of at least some infrared light, the infrared light can be used to drive and / or control the photosensitive electrode 96, preferably from the first side 91. Preferably, infrared light with a defined wavelength is used. In addition, due to the porosity of the porous layer, the redox active material contained in the medium 90 can diffuse through the porous layer and between the electrode. In some examples, the redox substance can exhibit a color and can become visible.

[0136] On or toward the second side 92, the device 200 may include a covering or protective coating (not shown) to protect the photosensitive electrode 96 from light that might otherwise enter the device from that side (e.g., ambient light). Additionally, in an embodiment, a color filter is provided associated with the first side 91 that can reflect specific colors of the visible spectrum. The color filter can be used in conjunction with the porous layer 100 to prevent all visible light from passing through the device from the front side 91 to the photosensitive electrode.

[0137] In an embodiment, the porous layer is used to protect the photosensitive electrode 96 from light in the visible spectrum and allow light in the near infrared spectrum to enter the photosensitive electrode 96. At the same time, the porous layer 109 preferably provides a background of a specific color, such as white. If the electrode 95 is a color-changing electrode, such as an electrochromic electrode or a photoelectrochromic electrode, the color-changing effect can be seen from the top side 91 without being blocked by the porous layer 109.

[0138] In an embodiment, the device of the present invention comprises a color-changing material, preferably, the color-changing material is selected from electrochromic materials, photochromic materials, photochromic materials, and materials belonging to two or more of the above categories.

[0139] For the purposes of this specification, the term "chromic" (eg in the expression "chromic material") includes "photochromic, electrochromic and / or photochromic".

[0140] A "photochromic material" is preferably a material that is capable of undergoing a color change under the influence of electromagnetic radiation, typically radiation having one or more specific, defined and limited wavelengths or wavelength ranges.

[0141] An “electrochromic material” is a material that changes color when excited by electrons, preferably provided by an electrode or a redox shuttle, which may be a substance dissolved in the medium 90 .

[0142] A "photochromic material" is a material that changes color when excited by electrons, which may be generated by light impinging on the material or on a photosensitizer material in electrical contact with the photochromic material.

[0143] The color changes mentioned above are generally reversible color changes and are non-destructive, that is, they will not damage the material.

[0144] The color-changing material is preferably deposited on the first electrode 95, or may be disposed in the medium 90 in a freely diffusive and / or non-deposited manner. If deposited, the color-changing material is preferably deposited on the inside and / or surface of the first electrode 95 so that it is exposed to the medium 90.

[0145] It is easy to understand that infrared light is preferably used to drive the photosensitive electrode 96, while the porous layer 100 prevents ambient visible light from reaching the photosensitive electrode. When the photosensitive electrode is activated by infrared light, a photocurrent is generated locally, which will cause the color change of the color-changing material, for example, through the redox shuttle present in the medium. The shuttle will diffuse to the counter electrode 95, and the color-changing material is deposited on the counter electrode 95 according to an embodiment of the present invention.

[0146] In place of a photosensitive electrode, any photosensitive element and / or compound may be used in the device, and may be protected from at least some visible light by the porous layer 100. For example, one or more color-changing materials (e.g., selected from photochromic materials and photoelectrochromic materials) may be provided in the device, e.g., in place of electrode 96, with the porous layer 100 provided to protect the photosensitive material from ambient visible light.

[0147] Although certain preferred embodiments of the present invention have been described and specifically illustrated above, the present invention is not intended to be limited to these embodiments. Various modifications may be made thereto without departing from the scope and spirit of the present invention as set forth in the appended claims.

[0148] Table 1: Selected embodiments, VIS range 100nm to 200nm.

[0149]

[0150]

[0151]

[0152] Table 1 Labels A, B, C, D: See description above.

[0153] Table 2: Selected embodiments, VIS range 250nm to 350nm.

[0154]

[0155]

[0156]

[0157] Table 2 Labels A, B, C, D: See description above.

Claims

1. An electrochemical device (200), comprising a porous layer (100-104) that selectively transmits light, wherein: - the porous layer prevents 60% or more of the photons of light having a wavelength within a continuous range of at least 100 nm extending within the visible spectrum from passing through the layer; and - said porous layer is transparent to at least 60% of the photons of light having a wavelength lying within a continuous range of at least 5 nm extending within the infrared (IR) spectrum, The visible light is light with a wavelength of 350nm to 750nm, and the infrared light is light with a wavelength of 751nm to 1400nm. 2 . The electrochemical device according to claim 1 , comprising one or both selected from a solvent and an electrolyte.

3. The electrochemical device of any preceding claim, selected from the group consisting of an electrochemical device, an electro-optical device, a photoelectric device, a photochemical device, a photoelectrochemical device, and a display, and devices belonging to two or more of the above device categories.

4. An electrochemical device according to any one of the preceding claims, comprising a first electrode (95) and a second electrode (96), and wherein: The porous layer is disposed between the first electrode and the second electrode.

5. An electrochemical device according to any one of the preceding claims, comprising a photosensitive material and / or a layer sensitive to visible light and / or infrared light.

6. The electrochemical device according to claim 1, comprising a photosensitive electrode (96), wherein: Preferably, the photosensitive electrode comprises the photosensitive material according to claim 5 and / or a layer sensitive to visible light and / or infrared light.

7. The electrochemical device according to any one of claims 1 and 6, comprising a material selected from the group consisting of an electrochromic material, a photoelectrochromic material and a photochromic material.

8. The electrochemical device according to any one of claims 5 to 7, wherein: The porous layer (100-104) is arranged in the device to prevent at least part of the ambient visible light from acting on one or more selected from the following: the photosensitive material, the layer sensitive to visible light and / or infrared light, and the photosensitive electrode (96) according to claim 6.

9. The electrochemical device according to any one of the preceding claims, which is a photochromic display and / or a photoelectrochromic display.

10. An electrochemical device according to any one of the preceding claims, wherein: The porous layers (100-104) include one or both selected from the following: - particles (20), preferably, the particles (20) are microparticles and / or nanoparticles, more preferably, the particles (20) are sintered microparticles and / or nanoparticles; and, - A porous substrate (30) and a coating (28.3) arranged on or around the porous substrate.

11. The electrochemical device according to claim 10, wherein: One, more than one or all of the particles and / or the coated porous substrate exhibits the effect of a Bragg reflector, and / or one, more than one or all of the particles and / or the coated porous substrate comprises multiple layers, preferably one, more than one or all of the particles and / or the coated porous substrate comprises multiple layers capable of interfering like a Bragg reflector.

12. The electrochemical device according to any one of claims 10 to 11, wherein: The particles and / or the coated porous substrate comprises a plurality of layers (28, 28.2, 28.3), preferably the plurality of layers comprises two layers or more layers, and preferably the plurality of layers comprises three layers or more layers.

13. The electrochemical device according to claim 12, wherein: The multilayer comprises nanolayers, sublayers or individual layers (31-36), which comprise materials having different refractive indices, or the nanolayers, sublayers or individual layers (31-36) are substantially composed of materials having different refractive indices.

14. A photochromic, electrochromic and / or photoelectrochromic display (200), comprising a porous layer (100-104) for selectively transmitting light, wherein: - the porous layer prevents 60% or more of the photons of light having a wavelength within a continuous range of at least 100 nm extending within the visible spectrum from passing through the layer; and - the porous layer is transparent to at least 60% of the photons of light having a wavelength lying within a continuous range of at least 5 nm extending within the infrared (IR) spectrum.

15. The display according to claim 14, comprising a medium (90) comprising one or both selected from a solvent and an electrolyte.

16. A display according to claim 14 or 15, comprising a first electrode (95) and a second electrode (96), and wherein: Preferably, the porous layer is disposed between the first electrode and the second electrode.

17. The display according to claim 16, wherein: The second electrode is a photosensitive electrode and / or the second electrode comprises a photosensitive material, and wherein the device comprises a color-changing material, preferably, the color-changing material is deposited in the first electrode (95) and / or deposited on the first electrode (95), or the color-changing material is arranged in the medium (90) according to claim 15.

18. The display according to claim 17, wherein: The porous layer is disposed in the device to prevent at least a portion of ambient visible light from reaching the photosensitive electrode.

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