Electrochromic Glazing

Abstract

The present invention relates to a material having a substrate coated with a first conductive coating, which comprises, starting from said substrate: - a first dielectric coating, - a metallic functional layer based on silver, a blocking layer located in direct contact with the silver-based metallic functional layer; - at least one zinc-based metal layer located above or below the silver-based metal functional layer, either in direct contact therewith or spaced apart by one or more layers having a total thickness of 20 nm or less, a second dielectric coating having at least one conductive oxide layer, the total thickness of the conductive oxide layers within the second dielectric coating being greater than 30 nm; It has.

Description

[Technical Field]

[0001] The present invention relates to the field of electrochromic glazing (EC). In particular, the present invention relates to electrically conductive coatings for electrochromic devices having a silver-based metallic functional layer with improved electrochemical properties. [Background technology]

[0002] Electrochromic devices, and in particular electrochromic glazing, are systems whose optical response can be adjusted under the action of an electric voltage in the visible or infrared range, thus making it possible to obtain easily adjustable, electrically controlled coatings.

[0003] Electrochromic devices are known to be characterized by an electrochromic system having a sequence of at least five layered elements essential to the operation of the device, i.e., the reversible color change following application of an appropriate power supply. These five layered elements are as follows: - a first transparent electrically conductive coating, - a first active layer acting as an electrode; - electrolyte layer, a second active layer acting as a counter electrode, and - A second transparent electrically conductive coating.

[0004] At least one active layer is based on an electrochromic material.

[0005] These five layered elements are generally in contact with one or two transparent substrates.

[0006] Electrochromic systems fall into three categories: - "All-solid" inorganic technology, - "Hybrid" technology - "All-polymer" technology.

[0007] In "all-solid" electrochromic systems, all layers are made of inorganic solid materials. These systems may have a single substrate. Examples of all-solid EC systems are described in EP 0867752, EP 0831360, WO 00 / 057243, and WO 00 / 071777.

[0008] Hybrid electrochromic systems have an inorganic active layer surrounding an electrolyte layer based on an ion-conducting polymer. These systems traditionally have two substrates surrounding the electrochromic system. Examples of hybrid EC systems are described in EP 0382623, EP 0518754, and EP 0532408.

[0009] In an "all-polymer" electrochromic system, the active layer and the electrolyte layer are based on a polymer.

[0010] The colouring / bleaching in the visible light range, or more generally the change in optical properties, results from the transfer of charges (ions / electrons) between the two active layers.

[0011] The active layer, based on an electrochromic material, can reversibly insert ions. When ions migrate into this layer, its optical properties change, reversibly changing from a bleached state to a colored state. The other active layer can also be based on an electrochromic material.

[0012] Inorganic electrochromic materials are mostly transition metal oxides and are divided into two groups: cathodically coloring oxides that color in the reduced state, such as tungsten oxide (WO), and anodically coloring oxides that color in the oxidized state, such as iridium oxide (IrOx) and nickel oxide (NiOx). A pair of cathodic and anodic electrochromic materials is generally selected, for example, a cathodic material that color in the intercalation state combined with an anodic material that bleaches in the intercalation state.

[0013] The electrolyte layer must have good ionic conductivity and be electrically insulating. The electrolyte in an electrochromic system ensures the passage of mobile ions within their electrochemical stability range. Theoretically, all monovalent ions, such as H, Li, Na, K, Ag, etc., and divalent ions, such as Zn, 2+ etc., and trivalent ions, e.g. Al 3+ etc. can be used. Lithium, alkali or hydrogen salts are particularly suitable.

[0014] For example, if a tungsten oxide (WO3) active layer is in contact with a lithium ion conducting electrolyte layer, when a voltage is applied, Li + Ions migrate between the electrodes. The following electrochemical reaction is observed at the cathode: 6+ O 2- 3(transparent)+xLi + +xe - →Li + x W 6+ 1-x W 5+ x O 2- 3 (blue).

[0015] Voltammetry can be used to determine the voltage range that provides the best contrast between the colored and bleached states. A voltammetric cycle or curve, or voltammetrogram (j = f(V)), consists of tracking the change in current density j over a sweep potential interval. The study of the change in current density is important for the electrochemical behavior of materials. From these curves, the coloring potential (Vcoloring), bleaching potential (Vbleaching), and stability range of the material, corresponding to an oxidation reaction in the anodic part (j>0) or a reduction reaction in the cathodic part (j<0), can be directly estimated.

[0016] Considering that the electrochromic device has a cathodic coloring active layer based on tungsten oxide and an electrolyte layer containing lithium ions, the colored state is observed at 2.3 V and the bleached state at 3.2 V (vs. Li / Li+).

[0017] Considering that the electrochromic device has an anode coloring active layer based on nickel oxide and an electrolyte layer containing lithium ions, the oxidation potential associated with lithium ion intercalation and deintercalation is about 4 V, while the bleaching voltage can be adjusted by doping the nickel oxide with 1 V to 2.5 V.

[0018] Considering all known polymer EC systems with an electrolyte layer containing lithium ions, the voltage range between the opaque and transparent states is 2 V to 4 V vs. Li / Li+.

[0019] As a result, in these EC systems, the reactions that enable coloring and bleaching occur within a potential window of 1 V to 4 V. The materials that make up the various layered elements of an electrochromic system must have an electrochemical stability range that is larger than the potential window required to obtain the coloring / bleaching phenomenon.

[0020] The "voltage stability range" of a material is the range of potentials to which the material can be exposed without undergoing oxidation or reduction reactions.

[0021] When a material is subjected to an electrochemical potential outside its stability range and is in the presence of corresponding ions, redox reactions occur.

[0022] In electrochromic systems, electrically conductive coatings are exposed to the electrochemical potential of the active materials they are in contact with. This means that the electrically conductive coatings of electrochromic devices must be stable within a potential window of 2V to 4V, or even 1V to 4V, relative to Li / Li+. Therefore, electrically conductive coatings must have an electrochemical stability range relative to the Li+ / Li pair, preferably 1V to 4V. The materials that make up these conductive coatings must not undergo redox reactions within this voltage range.

[0023] Known electrically conductive coatings include conductive functional layers based on transparent conductive oxides, such as indium tin layers or fluorine-doped tin layers, or metallic functional layers, in particular based on silver.

[0024] While electrically conductive coatings based on conductive oxide layers offer excellent electrochemical stability, they lack sufficient conductivity at high optical transmittances (>80%). As a result, non-uniform switching and / or slower switching speeds occur as the surface area of ​​the EC system increases. Finally, some applications, such as automotive applications, may require additional processing steps, such as hardening or bending. These additional steps are likely to alter the conductive oxide coating. Indeed, these coatings must be thick to achieve the desired resistance. However, such thick coatings are prone to cracking during heat treatment.

[0025] Conductive coatings with silver-based metal functional layers offer excellent electrical conductivity and high transparency. However, the low electrochemical stability of the silver functional layer limits the use of this type of conductive coating in electrochromic devices. In particular, silver-based conductive coatings undergo redox reactions in the range of 1 V to 4 V versus the Li / Li+ pair. At low potentials, these reactions result in the reduction of Ag materials, the formation of metal alloys (e.g., LiAg), or the generation of reducing gas (hydrogen). At high potentials, these reactions result in the oxidation of Ag+ materials, the formation of oxides (AgO), and / or the generation of oxidizing gas (oxygen). In the context of high-potential reactions, the "corrosion" of materials may also be referred to.

[0026] Known electrically conductive coatings of this type are: - optionally a first dielectric layer or a first dielectric coating, - a metal layer based on silver, optionally a blocking layer; - a second dielectric layer or dielectric coating, It has.

[0027] Cyclic voltammograms were performed using a three-electrode configuration with a lithium metal counter electrode, a lithium metal reference electrode, and a working electrode containing the electrically conductive coating being tested to determine the voltage stability range of these electrically conductive coatings. The electrolyte was a LiClO4 / PC solution. The working electrode had a 2 mm glass substrate coated with a known silver-based electrically conductive coating, with the sequence (SiN / SnZnO / Al-doped ZnO / Ag) starting from the substrate. Voltammograms were acquired over a potential window of 2 to 4 V vs. Li / Li+ at a scan rate of 2 mV / s.

[0028] No oxidation reaction is observed between 2 V and 3.4 V. A slight increase in current density is observed near 3.4 V vs. Li / Li+, followed by a sharp increase near 3.7 V vs. Li / Li+. This sharp increase is due to the metallic Ag being converted to Ag +This is due to the fact that the conductive coatings are oxidized to ions and dissolve in the electrolyte. This means that such conductive coatings cannot be used in electrochromic devices unless the available contrast of the EC device is limited by imposing a potential below 3.7 V. In this case, complete bleaching or coloring is not achieved. Summary of the Invention [Problem to be solved by the invention]

[0029] To take advantage of the improved optical and conductive properties of silver-based electrically conductive coatings in electrochromic devices, there is a need to extend the range of their electrochemical stability.

[0030] The present invention relates to electrically conductive coatings comprising a silver-based metallic functional layer with improved electrochemical stability. The coatings of the present invention are particularly suitable for use in electrochromic devices. [Means for solving the problem]

[0031] Applicants have discovered that the use of certain blocking layers in combination with a zinc or indium based metal layer adjacent to a silver based functional layer improves electrochemical stability, particularly near 3.7 V vs. Li / Li+. This improved electrochemical stability makes the drug-based conductive coating suitable for EC applications.

[0032] The present invention relates to a material having a substrate that, starting from the substrate, is coated with a first conductive coating comprising: - a first dielectric coating, - functional metal layers, including layers based on silver; a blocking layer, which is located in direct contact with the silver-based metallic functional layer and is selected from metal layers, metal nitride layers, metal oxide layers and metal oxynitride layers based on metals or metal alloys of one or more elements selected from titanium, nickel, chromium, tantalum and niobium, aluminum oxide layers and silicon oxide layers, at least one zinc- or indium-based metal layer located above or below this silver-based metal functional layer, either in direct contact therewith or spaced apart by one or more layers having a total thickness of 20 nm or less, - preferably a second dielectric coating having at least one conductive oxide layer, the total thickness of the conductive oxide layers within the second dielectric coating being greater than 30 nm, preferably greater than 40 nm.

[0033] The present invention increases the stability range of silver-based electrically conductive coatings to above 3.7 V vs. Li / Li+.

[0034] The present invention also relates to a conductive coating having a metallic functional layer, which comprises a layer based on silver, which is preferably transparent and electrochemically stable in a potential window of 2-4 V vs. Li / Li+. - a metallic functional layer having a layer based on silver, a blocking layer located in direct contact with the silver-based metallic functional layer; - at least one zinc-based metal layer located above or below the silver-based metal functional layer, either in direct contact therewith or spaced apart by one or more layers having a total thickness of 20 nm or less, It has.

[0035] The most advantageous properties of the present invention are obtained after a high temperature heat treatment. The electrically conductive coating or material of the present invention, i.e., the substrate coated with the electrically conductive coating, is preferably subjected to a high temperature heat treatment, i.e., a treatment at a temperature above 250°C, preferably above 300°C, above 400°C, or above 500°C.

[0036] The purpose of the blocking layer is to improve the electrochemical properties of the silver layer. The blocking layer is preferably deposited in the form of a metal or nitride based on one or more elements selected from nickel, iron, zirconium, titanium, or tungsten. The purpose of these blocking layers is to protect the silver layer and prevent the diffusion of ions, such as Li+ ions, from the active layer.

[0037] Without wishing to be bound by any particular theory, it is likely that a portion of the zinc or indium metal layer alloys with the silver, especially during high temperature heat treatments, and the blocking layer controls this doping.

[0038] Each of these layers contributes to improving the electrochemical stability of the silver-based metal layer, but the combination of the blocking layer and the zinc layer provides the best results in terms of high contrast in the final EC device and electrochemical stability of the electrically conductive coating.

[0039] The zinc or indium metal layer must be adjacent to the silver layer. It can be located above, below, or on both sides of the silver layer.

[0040] This particular coating structure makes it possible to obtain transparent electrically conductive coatings with electrochemical resistance compatible with EC systems, while at the same time providing high electrical conductivity properties and high light transmission levels, particularly light transmission levels of more than 60%, 70%, or 80%.

[0041] The present invention also relates to materials having one or more of the following properties: The blocking layer has a thickness of 0.1 to 5.0 nm or 0.5 to 2 nm. the blocking layer is selected from titanium nitride layers, metal layers based on nickel and / or chromium, nickel and / or chromium oxide layers, aluminum oxide layers, silicon oxide layers; the blocking layer is selected from nickel-based metal layers containing at least 20% by weight of nickel relative to the weight of the nickel-based metal layer; the metal layer based on zinc or indium is spaced from the metal functional layer based on silver by at least one blocking layer; all layers separating a silver-based metallic functional layer from a zinc- or indium-based metallic layer have a thickness of less than or equal to 10 nm; A metal layer based on zinc or indium lies above a metal functional layer based on silver. The thickness of the metal layer based on zinc or indium is between 0.2 and 10 nm. the zinc-based metal layer comprises at least 20% by weight of zinc, based on the weight of the zinc-based metal layer; the second dielectric coating comprises a conductive oxide layer selected from tin-indium mixed oxide or zinc oxide doped with aluminum and / or gallium; the second dielectric coating comprises a conductive oxide layer based on zinc oxide doped with aluminum, with a thickness of more than 50 nm; the first dielectric coating comprises at least one crystallized dielectric layer, in particular based on zinc oxide, optionally doped with at least one other element, such as aluminium; the first dielectric coating comprises a layer based on aluminum and / or zirconium silicon nitride or oxynitride and / or a layer based on zinc tin oxide; The stack has been heat treated at a temperature above 300°C, preferably above 500°C, above 550°C or above 600°C. The silver-based functional layer contains zinc. The substrate is made of glass, in particular soda-lime-silica glass, or a polymeric organic material. the material further comprises a first active layer comprising an electrochromic material located in contact with the electrically conductive coating. the material further comprises an electrolyte layer located in contact with the first active layer comprising the electrochromic material, preferably the electrolyte being a lithium ion conducting electrolyte. the material further comprises a second active layer located in contact with the electrolyte layer. the material further comprises a second electrically conductive coating located in contact with the electrolyte layer.

[0042] The present invention also relates to an electrochromic system comprising: a material according to the invention, comprising a first transparent electrically conductive coating. a first active layer comprising an electrochromic material; - electrolyte layer, a second active layer, and - a second transparent electrically conductive coating, - Optionally a substrate.

[0043] The electrochromic material of the active layer can be based on inorganic materials, such as tungsten oxide, nickel oxide, iridium oxide, cerium oxide, etc., or organic materials, such as electronically conducting polymers, such as polyaniline or (poly(3,4-ethylenedioxythiophene) (PEDOT)), or Prussian blue. These materials can insert cations, in particular protons or lithium ions.

[0044] The electrochromic material of the first active layer may be based on an oxide of an element selected from tungsten, nickel, iridium, chromium, iron, cobalt or rhodium, or a mixed oxide of at least two of these elements, in particular a mixed oxide of nickel and tungsten. It is preferably based on tungsten oxide.

[0045] The electrochromic material of the second active layer or counter electrode is preferably based on an oxide of an element selected from tungsten, nickel, iridium, chromium, iron, cobalt and rhodium, or a mixed oxide of at least two of these elements, in particular a mixed oxide of nickel and tungsten. It is preferably based on nickel oxide or iridium oxide (anodic electrochromic material).

[0046] If the electrochromic material of the first active layer is tungsten oxide, i.e., a cathodic electrochromic material whose colored state corresponds to the most reduced state, then an anodic electrochromic material based on, for example, nickel or iridium oxide can be used for the counter electrode, in particular a layer of vanadium-tungsten mixed oxide or nickel-tungsten mixed oxide.

[0047] The thickness of the active layer is generally 50 nm to 600 nm, particularly 150 nm to 250 nm.

[0048] The thickness of the electrolyte layer can be 1 nm to 1 mm. When the electrolyte layer is made of an inorganic material, its thickness is preferably 1 to 300 nm, 1 to 50 nm, or 1 to 10 nm. When the electrolyte layer is made of a polymer material, its thickness is preferably 100 to 800 μm, or 100 to 500 μm.

[0049] The two electrically conductive coatings need to be connected to their respective power connectors, such as bus bars and wires, which are brought into contact with the respective electrically conductive coatings to provide the appropriate power supply.

[0050] The present invention also relates to an electrochromic system having two substrates held together by a housing or frame. [Brief explanation of the drawings]

[0051] [Figure 1]FIG. 1 shows a voltammetric cycle based on a three-electrode configuration with a lithium metal counter electrode, a lithium metal reference electrode, and a working electrode with various electrically conductive coatings.

[0052] [Figure 2] FIG. 2 shows a voltammetric cycle based on a three-electrode configuration with a lithium metal counter electrode, a lithium metal reference electrode, and a working electrode with various electrically conductive coatings.

[0053] [Figure 3] FIG. 3 is an enlarged view of FIG. 2 at about 3.7V. DETAILED DESCRIPTION OF THE INVENTION

[0054] Throughout this specification, the substrate according to the invention is assumed to be horizontally placed. The electrically conductive coating is deposited above the substrate. The meaning of the expressions "above" and "below", "below" and "upper" shall be considered in this orientation. Unless otherwise specified, the expressions "above" and "below" do not necessarily mean that two layers and / or coatings are arranged in contact with each other. When it is specified that a layer is deposited "in contact" with another layer or coating, this means that one or more layers cannot be inserted between these two layers (or layer and coating).

[0055] All optical properties presented herein are obtained according to the principles and methods described in European Standard EN 410 for the measurement of the optical and solar properties of glazing used in the building industry.

[0056] The preferred properties described in the remainder of the description are applicable both to the material according to the invention and, where appropriate, to the glazing or system according to the invention.

[0057] The electrically conductive coating is deposited by magnetic field assisted cathode sputtering (magnetron method). According to this advantageous embodiment, all layers of the coating are deposited by magnetic field assisted cathode sputtering.

[0058] Unless otherwise stated, thicknesses referred to herein are physical thicknesses.

[0059] The present invention is suitable for single-layer silver-based functional coatings. The solution is also suitable for coatings with multiple silver-based functional layers, especially two or three functional layers. The coating has at least one or only one silver-based metal functional layer.

[0060] The silver-based functional metallic layer comprises at least 95.0 wt. %, preferably at least 96.5 wt. %, more preferably at least 98.0 wt. % silver, based on the weight of the functional layer, before or after heat treatment.

[0061] Preferably, the silver-based functional metal layer before heat treatment contains less than 1.0 wt % of metals other than silver, based on the weight of the silver-based functional metal layer.

[0062] After the heat treatment, the silver-based functional metal layer may contain a proportion of zinc or indium. The zinc or indium doping may be measured, for example, by an electroprobe microanalyzer (EPMA) or atom probe tomography.

[0063] The thickness of the silver-based functional layer is comprised between 5 and 25 nm.

[0064] The zinc-based metal layer is present in the dielectric coating in contact with the silver-based metal functional layer, meaning that the zinc-based metal layer is not separated from the silver-based metal functional layer by another silver-based metal functional layer.

[0065] The presence of a zinc or indium metal layer adjacent to a silver layer encourages migration of zinc metal element into the silver layer, particularly during heat treatment, and the presence of a blocking layer in contact with the silver layer is believed to slow the diffusion of zinc or indium metal through the silver layer.

[0066] Consider a case where a zinc-based metal layer is located above a silver layer. If no blocking coating layer is present, metallic zinc elements will diffuse at temperatures lower than the heat treatment temperature and easily penetrate the silver layer without being sufficiently retained. Conversely, if a blocking coating layer is inserted between the silver layer and the zinc layer, the blocking layer can act as a barrier and slow down the diffusion of metallic zinc elements, thereby retaining them within the silver layer.

[0067] To a lesser extent, the use of a blocking underlayer also serves to prevent the diffusion of metallic zinc elements and confine them to the vicinity of the silver layer. A configuration according to this embodiment can be advantageous.

[0068] Preferably, the blocking layer is located between the functional layer and the zinc or indium based metal layer.

[0069] In the following, metal layers based on zinc or indium are defined as they are obtained during deposition, i.e., before heat treatment. Insofar as heat treatment induces migration of the metallic zinc element, it is not possible to determine with certainty how this zinc or indium metal layer will change as a result of heat treatment, depending on the thickness deposited.

[0070] "Metal layer" is understood to mean a layer having less than 30%, less than 20%, or less than 10% of oxygen and / or nitrogen in atomic percent within the layer.

[0071] The layers are deposited in metallic form. After deposition and before heat treatment, they must contain no more than 10% oxygen and / or nitrogen. However, depending on the nature of the layer deposited directly on top of them, these zinc-based metal layers may be susceptible to partial oxidation, leading to a high percentage of oxygen or nitrogen. However, these percentages are lower than 30% or 20%. In any case, at least a portion of the thickness of these zinc- or indium-based metal layers is not oxidized or nitrided.

[0072] The zinc-based metal blocking layer (before heat treatment) comprises at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% by weight of zinc, based on the weight of the zinc-based metal layer.

[0073] The indium-based metal blocking layer (before heat treatment) comprises at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% by weight of indium, based on the weight of the indium-based metal layer.

[0074] The zinc-based metal layer may be selected from: - a metal layer of zinc, - a metal layer of doped zinc, - Metal layer based on zinc alloy.

[0075] According to the present invention, the term "zinc metal layer" refers to a metal layer of pure zinc which may contain minor impurities, in which the total mass of zinc is at least 99% by mass relative to the mass of the zinc-based metal layer.

[0076] According to the present invention, the doped zinc layer comprises at least 90.0%, at least 95%, at least 96%, at least 97%, at least 98% or at least 99% by weight of zinc, based on the weight of the zinc-based metal layer.

[0077] The doped zinc layer may be selected from layers based on zinc and at least one element selected from titanium, nickel, aluminum, tin, niobium, chromium, magnesium, copper, silicon, silver, or gold.

[0078] According to the invention, the zinc alloy based layer contains at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80% or at least 90% zinc relative to the weight of the zinc based metal layer.

[0079] The zinc alloy layer may be selected from layers based on zinc and at least one element selected from titanium, nickel, chromium, and tin, such as binary zinc-titanium alloys, such as Zn2Ti, or ternary zinc-nickel-chromium alloys, such as ZnNiCr.

[0080] The thickness of the metal layer based on zinc or indium is in the range of 0.2 to 10 nm.

[0081] The thickness of the zinc or indium based metal layer can be either: - 0.2 nm or more, 0.5 nm or more, 1.0 nm or more, 1.2 nm or more, 1.5 nm or more, 2 nm or more, and / or - 10nm or less, 8nm or less, 7nm or less, 6nm or less, 5nm or less, or 4nm or less.

[0082] Preferably, one or more zinc or indium based metal layers are located above the silver based metal functional layer.

[0083] The coating has a blocking layer located above and in direct contact with the silver-based metallic functional layer and / or a blocking layer located below and in direct contact with the silver-based metallic functional layer.

[0084] Preferably, one or more zinc- or indium-based metal layers are located above the silver layer and above the blocking layer, in which case the zinc- or indium-based metal layer is located above the silver-based metal functional layer and spaced from this layer by at least one blocking coating layer.

[0085] The blocking layer is selected from a metal layer, a metal nitride layer, a metal oxide layer, and a metal oxynitride layer based on a metal or metal alloy of one or more elements selected from titanium, nickel, chromium, tantalum, and niobium, such as Ti, TiN, TiOx, Nb, NbN, Ni, NiN, Cr, CrN, NiCr, or NiCrN.

[0086] When these blocking layers are deposited in the form of metals, nitrides, or oxynitrides, they may be partially or completely oxidized, depending on their thickness and the nature of the layers surrounding them, for example, during the deposition of a subsequent layer or by oxidation in contact with an underlying layer.

[0087] The blocking layer may be selected from the following: a metal layer, in particular a layer of nickel-chromium (NiCr) alloy or titanium, - Metal nitride layers, in particular titanium nitride or nickel nitride and / or chromium nitride.

[0088] Advantageously, the blocking layer is a nickel-based metallic layer, which comprises at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% by weight of nickel, based on the weight of the nickel-based metallic layer (before heat treatment).

[0089] The nickel-based metal layer may be selected from: - a metal layer of nickel, - a metal layer of doped nickel, - Metal layer based on nickel alloy.

[0090] The metallic layer based on a nickel alloy may be based on a nickel-chromium alloy.

[0091] Each blocking layer has a thickness of 0.1 to 5.0 nm. The thicknesses of these blocking layers are: at least 0.1 nm, at least 0.2 nm, at least 0.5 nm, and / or up to 5.0nm, up to 4.0nm, up to 3.0nm, up to 2.0nm, It is possible.

[0092] In an advantageous embodiment, the coating also has crystallized dielectric layers located below and adjacent to the silver layer, these crystallized dielectric layers being typically zinc oxide based layers.

[0093] The metal layer based on zinc or indium may be located as follows: - above a metallic functional layer based on silver, a metallic layer of zinc is in contact with the metallic functional layer based on silver (order Ag / Zn); - above a silver-based metallic functional layer, a zinc metallic layer spaced from the silver-based metallic functional layer by at least one blocking coating layer (sequence Ag / / blocking layer / / Zn); - above the silver-based metal functional layer and below and in contact with the conductive oxide layer, the zinc metal layer being spaced from the silver-based metal functional layer by at least one blocking coating layer (in the order Ag / / blocking layer / / Zn / / conductive oxide layer). - Beneath a metallic functional layer based on silver, a metallic layer of zinc is in contact with the metallic functional layer based on silver (order Zn / Ag). a metal layer of zinc below the silver-based metal functional layer, spaced from the silver-based metal functional layer by at least one blocking underlayer (sequence Zn / / blocking layer / Ag); - below a silver-based metal functional layer, above and in contact with a crystallized dielectric layer, and a zinc metal layer in contact with the silver-based metal functional layer (order crystallized layer / Zn / Ag). - a zinc metal layer below the silver-based metal functional layer and above and in contact with the crystallized dielectric layer, the zinc metal layer being spaced from the silver-based metal functional layer by at least one blocking underlayer (sequence: crystallized layer / Zn / / blocking layer / / Ag); - below a silver-based metal functional layer and below and in contact with a crystallization dielectric layer, which is in contact with or spaced apart from the silver-based metal functional layer by at least one blocking underlayer (sequence Zn / crystallization layer / / optionally blocking layer / / Ag).

[0094] The physical thickness of all layers separating the silver-based metal functional layer from the zinc- or indium-based metal layer can be 0-15.0 nm, 0-10 nm, 0-5 nm, 0.2-5 nm, 0.5-3 nm, or 0.8-1.5 nm.

[0095] The thickness of all layers separating the silver-based metallic functional layer from the zinc or indium-based metallic layer may be: - 0.2 nm or more, 0.4 nm or more, 0.5 nm or more, 5 nm, 1 nm or more, 2 nm or more, 3 nm or more, 4 nm or more, 5 nm or more, 6 nm or more, 7 nm or more, 8 nm or more, or 9 nm or more; and / or - 20nm or less, 15nm or less, 13nm or less, 12nm or less, 11nm or less, 10nm or less, 9nm or less, 8nm or less, 7nm or less, 6nm or less, 5nm or less, 4nm or less, 3nm or less, 2nm or less, 1.5nm or less.

[0096] A configuration in which a zinc or indium based metal layer overlies and is separated from a silver based metallic functional layer by a blocking coating layer is believed to provide the best results.

[0097] In these configurations, a blocking underlayer may also be used, which improves the mechanical resistance and is in combination with an overlying metal layer based on zinc or indium, which is either in direct contact with the silver layer or is spaced from the silver layer by a blocking overlayer.

[0098] According to the present invention, "closely located layer" is understood to mean a layer that is located, in order of increasing priority, less than 15 nm, less than 10 nm, less than 5 nm, less than 4 nm, less than 3 nm, less than 2 nm from another layer.

[0099] The following embodiments are particularly advantageous because they provide the best results: a metal layer based on zinc or indium is located adjacent to the silver layer, and / or the zinc or indium based metal layer is separated from the silver layer by at least one blocking layer, and / or a metal layer based on zinc or indium is located above the silver layer, and / or The coating has a blocking layer directly above and in contact with the silver-based metallic functional layer.

[0100] To be effective, zinc or indium based metal layers must allow the zinc or indium metal element to diffuse into the silver layer, provided that these zinc layers are separated from the silver layer by: by one or more excessively thick dielectric layers, such as excessively thick zinc tin oxide layers, and / or - by one or more barrier dielectric layers, such as silicon and / or aluminum and / or zirconium nitride layers; The diffusion of these zinc or indium metal elements can be significantly reduced or even prevented, and the zinc or indium based metal layer becomes ineffective in terms of improving electrochemical properties.

[0101] The electrically conductive coating may comprise one or more zinc or indium based metal layers.

[0102] The electrically conductive coating includes at least one functional layer and at least two dielectric coatings with at least one dielectric layer, whereby each functional layer is disposed between two dielectric coatings.

[0103] A "dielectric coating" in the sense of the present invention should be understood to mean that there may be one or several layers of different materials within the coating. A "dielectric coating" according to the present invention comprises mainly dielectric layers. However, according to the present invention, these layers may also comprise layers of another nature, in particular absorbing layers, such as absorbing metal layers.

[0104] "Identical" dielectric coatings are considered to be those located on: - between the substrate and the first functional layer, between each silver-based metal functional layer, - Above the last functional layer (farthest from the substrate).

[0105] A "dielectric layer" in the sense of the present invention should be understood to mean that the material is "non-metallic", i.e. not metallic, by its nature. In the context of the present invention, this term refers to a material having an n / k ratio of 5 or greater over the entire visible wavelength range (380 nm to 780 nm). n refers to the real part of the refractive index of the material at a given wavelength, and k represents the imaginary part of the refractive index at a given wavelength: the n / k ratio is calculated at a given wavelength where n and k are identical.

[0106] The thickness of the dielectric coating corresponds to the sum of the thicknesses of the layers that make it up.

[0107] The coating has a thickness of more than 15 nm, preferably between 15 and 200 nm.

[0108] The dielectric layer of the coating has the following properties, alone or in combination: They are deposited by magnetic field assisted sputtering. They are selected from oxides or nitrides of one or more elements selected from titanium, silicon, aluminum, zirconium, tin, indium and zinc. They have a thickness of more than 2 nm, preferably between 2 and 100 nm.

[0109] The dielectric coating above the silver-based metallic functional layer requires that the electrically conductive coating be sufficiently conductive to maintain its electrode function.

[0110] The dielectric coating above the silver-based metallic functional layer comprises at least one conductive oxide layer selected from mixed oxides of tin and indium, tin-doped indium oxide (ITO, "indium tin oxide"), doped zinc oxide, such as aluminum-doped zinc oxide (AZO) and / or gallium-doped zinc oxide, doped ruthenium oxide, and fluorine-doped tin oxide (SnO2:F).

[0111] Preferred materials are indium tin oxide (ITO) or zinc oxide doped with aluminum and / or gallium.

[0112] The sum of the thicknesses of all conductive oxide layers in the dielectric coating directly above the silver-based functional layer is greater than 50 nm, or greater than 60 nm.

[0113] The total thickness of all conductive oxide layers located in the dielectric coating directly above the silver-based functional layer is less than 150 nm, less than 100 nm, or less than 80 nm.

[0114] Preferably, the dielectric coating located directly above the silver-based metallic functional layer comprises at least one conductive oxide layer with a thickness of more than 50 nm or 60 nm.

[0115] Preferably, the dielectric coating located directly above the silver-based functional layer comprises at least one conductive oxide layer based on aluminum-doped zinc oxide having a thickness of more than 50 nm or 60 nm.

[0116] According to one embodiment, the dielectric coating may have at least two layers: a layer of aluminum doped zinc oxide and a layer of mixed indium tin oxide (ITO).

[0117] According to the present invention, indium tin oxide (ITO) is understood to mean a mixed oxide or mixture obtained from indium (III) oxide (In2O3) and tin (IV) oxide (SnO2), preferably with 70-95% by weight of the former oxide and 5-20% by weight of the latter. A typical mass ratio is about 90% In2O3 to about 10% SnO2.

[0118] According to the present invention, a conductive oxide layer based on zinc oxide may contain at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 95% by weight of zinc, compared to the total weight of all elements forming the zinc oxide layer, excluding oxygen and nitrogen. To be sufficiently conductive, the zinc oxide layer is doped with at least one other element, known as a "doping element." Thus, the zinc oxide layer may contain one or more doping elements selected from aluminum, titanium, niobium, zirconium, magnesium, copper, silver, gold, silicon, molybdenum, nickel, chromium, platinum, indium, tin, and hafnium, preferably aluminum.

[0119] Conductive layers based on doped zinc oxide may include: at least 1%, at least 2%, or at least 5% by weight, and / or - maximum 15% by weight or 10% by weight, The doping element relative to the total mass of all elements constituting the zinc oxide layer, excluding oxygen and nitrogen.

[0120] The dielectric coating underneath the silver-based metal functional layer does not necessarily have to be conductive. Advantageously, it can have a crystallization layer, also known as a stabilization layer or wetting layer. "Stabilization layer" is understood to mean a layer made of a material capable of stabilizing the interface with the functional layer. These layers are generally based on zinc oxide.

[0121] The zinc oxide based layer comprises at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, at least 95% by weight, at least 96% by weight, at least 97% by weight, at least 98% by weight, at least 99% by weight or 100% by weight of zinc compared to the total weight of all elements forming the zinc oxide based layer other than oxygen and nitrogen.

[0122] In order to be correctly crystallized by magnetron sputtering, a layer based on zinc oxide advantageously contains at least 80% by weight, or even 90% by weight, of zinc relative to the total weight of all elements constituting the zinc oxide layer, excluding oxygen and nitrogen.

[0123] The zinc oxide based layer may contain one or more elements selected from aluminum, titanium, niobium, zirconium, magnesium, copper, silver, gold, silicon, molybdenum, nickel, chromium, platinum, indium, tin and hafnium, preferably aluminum.

[0124] The zinc oxide based layer may optionally be doped with at least one other element, such as aluminum.

[0125] The zinc oxide based layer comprises, in order of increasing preference, at least 80% by weight, at least 90% by weight, at least 95% by weight, at least 98% by weight, at least 100% by weight of oxygen relative to the total weight of oxygen and nitrogen.

[0126] Preferably, the dielectric coating located directly below the silver-based functional metal layer comprises at least one crystallized dielectric layer, in particular based on zinc oxide, optionally doped with at least one other element, such as aluminum.

[0127] These zinc oxide layers have the following thicknesses: at least 1.0 nm, at least 2.0 nm, at least 3.0 nm, at least 4.0 nm, or at least 5.0 nm; and / or The maximum is 25 nm, the maximum is 15 nm, the maximum is 10 nm, or the maximum is 8.0 nm.

[0128] Preferably, the dielectric coating located directly below the silver-based functional metal layer comprises at least one dielectric layer with a barrier function. A dielectric layer with a barrier function (hereinafter barrier layer) is understood to mean a layer made of a material that, at high temperatures, forms a barrier against the diffusion of oxygen and water originating from the surrounding atmosphere or from the transparent substrate towards the functional layer. Such a dielectric layer may be selected from the following layers: based on compounds of silicon and / or aluminum and / or zirconium, optionally doped with at least one other element, selected from oxides such as SiO2, nitrides such as silicon nitride Si3N4 and aluminum nitride AlN, and oxynitrides SiOxNy; - based on zinc tin oxide, - Based on titanium dioxide.

[0129] These dielectric layers with barrier function have the following thicknesses, in order of increasing priority: - 40 nm or less, 30 nm or less, 25 nm or less, and / or - 5nm or more, 10nm or more, or 15nm or more.

[0130] Preferably, the first dielectric coating comprises: layers based on nitrides or oxynitrides of aluminum and / or silicon and / or zirconium, and / or - layers based on mixed oxides of zinc and tin, and / or - a layer based on nitrides or oxynitrides of aluminum and / or silicon and / or zirconium and a dielectric layer based on a mixed oxide of zinc and tin located above and preferably in contact with the layer based on nitrides or oxynitrides of aluminum and / or silicon and / or zirconium.

[0131] The zinc tin oxide based layer may have a thickness of 2 nm to 30 nm, preferably 5 nm to 20 nm. The aluminum and / or silicon and / or zirconium nitride or oxynitride based layer may have a thickness of 2 nm to 30 nm, preferably 5 nm to 20 nm. The zinc tin oxide based layer is located below the zinc oxide based layer and is preferably in contact with it.

[0132] The substrate coated with the electrically conductive coating, or the coating alone, is intended to be subjected to a heat treatment, however, the present invention also relates to non-heat treated materials.

[0133] The electrically conductive coating may not have been subjected to a heat treatment at a temperature above 500°C, preferably above 300°C.

[0134] The coating may have been subjected to a heat treatment at a temperature above 300°C, preferably above 500°C.

[0135] The heat treatment is selected from annealing, e.g., "rapid thermal processing" annealing, e.g., laser or flash lamp annealing, tempering, and / or bending. Rapid thermal processing annealing is described, for example, in WO 2008 / 096089. The heat treatment temperature (when coating) is greater than 300°C, preferably greater than 400°C, and more preferably greater than 500°C.

[0136] The substrate coated with the coating can be bent glass or tempered glass.

[0137] The transparent substrate according to the invention is preferably made of a rigid inorganic material, such as glass, or organic and based on (or made of) a polymer.

[0138] The organic transparent substrate according to the invention may also be made of a polymer and may be rigid or flexible. Examples of suitable polymers according to the invention include, in particular: - polyethylene, polyesters, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or polyethylene naphthalate (PEN); - polyacrylates, such as polymethyl methacrylate (PMMA); - polycarbonate; - polyurethane; - polyamide; - polyimide; - fluorinated polymers, such as fluorinated esters, such as ethylene-tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene (ECTFE), fluorinated ethylene-propylene copolymers (FEP), etc.; photocrosslinkable and / or photopolymerizable resins, such as thiolene, polyurethane, urethane acrylate, polyester acrylate resins, and - Polythiourea.

[0139] The substrate is preferably a sheet of glass or of glass ceramic.

[0140] The substrate is preferably transparent, colorless (in which case it is clear glass or extra clear glass), or colored, for example blue, gray, or bronze. The glass is preferably of the soda-lime-silica type, but it may also be of the borosilicate or aluminoborosilicate type.

[0141] According to a preferred embodiment, the substrate is made of glass, in particular soda-lime-silica glass, or a polymeric organic material.

[0142] Advantageously, the substrate has at least one dimension greater than or equal to 1 m, or even greater than or equal to 2 m, or even greater than or equal to 3 m.

[0143] The thickness of the substrate generally varies from 0.05 mm to 19 mm. If the substrate is inorganic, its thickness is preferably from 0.7 mm to 9 mm, in particular from 2 mm to 8 mm, or even from 4 mm to 6 mm. The substrate may be flat or curved, or even flexible. If the substrate is organic, its thickness is preferably from 1 mm to 2 mm. [Example]

[0144] I. Electrically conductive coating

[0145] The electrically conductive coating was deposited by cathode sputtering onto a transparent glass substrate, which was a 2.1 mm aluminosilicate glass substrate.

[0146] The functional layer (F) is a layer based on silver (Ag).

[0147] The dielectric coating has the following layers: - a layer based on silicon nitride, - a layer based on zinc tin oxide, - aluminum-doped zinc layer, - Indium tin layer.

[0148] The blocking layer is selected from titanium, titanium nitride, nickel chromium, and zinc layers.

[0149] The deposition conditions of the layers, deposited by sputtering (“magnetron cathode” sputtering), are summarized in Table 1. [Table 1]

[0150] Table 2 lists the material and physical thickness in nanometers (unless otherwise specified) for each layer or coating that forms the coating based on its position relative to the substrate carrying the stack (last row at the bottom of the table). [Table 2]

[0151] The initial dielectric coating has a sequence of SiN / SnZnO / ZnO to prevent diffusion of species from the substrate, reduce surface roughness, and optimize silver quality.

[0152] II. Determination of electrochemical properties

[0153] Voltammetric cycles were performed to determine the electrochemical properties of the conductive coatings relative to mobile electrolyte species, such as Li / Li+. To achieve this, the current response resulting from a continuous change in the potential of the conductive coating (used as the working electrode) where the electrochemical reaction under study occurs is measured.

[0154] 1 and 2 show voltammetric cycles based on a three-electrode configuration with a lithium metal counter electrode, a lithium metal reference electrode, and a working electrode with various electrically conductive coatings. The electrolyte is a LiClO4 / PC solution.

[0155] Voltammograms are acquired in a potential window of 2–4 V vs. Li / Li+ at a scan rate of 2 mV / s.

[0156] FIG. 3 is an enlarged view of FIG. 2 at about 3.7V.

[0157] The electrically conductive coating tested in Figure 1 was not heat treated. The electrically conductive coating tested in Figure 2 was heat treated at 600°C for 8 minutes.

[0158] 1. No heat treatment

[0159] In Figure 1, for Coating 1 (Rev. 1) and Coating 7 (Rev. 7), which are coatings with titanium or zinc metal blocking layers, no oxidation reaction is observed between 2 V and 3.4 V. A slight increase in current density is observed near 3.4 V vs. Li / Li+, followed by a sharp increase near 3.7 V vs. Li / Li+. This sharp increase is due to the oxidation of metallic Ag to Ag+ ions, which dissolve in the electrolyte. This indicates that such electrically conductive coatings cannot be used in electrochromic devices. The mere presence of a zinc-based metal layer or a metallic titanium layer adjacent to a silver layer does not have any beneficial effect. The presence of a redox peak indicates electrode degradation.

[0160] Coating 6 (Rev. 6) with a NiCr blocking layer shows no redox peaks. Without heat treatment, a NiCr-based blocking layer alone improves the stability range of silver-based electrically conductive coatings.

[0161] Inv.4 according to the invention, a coating with a NiCr-based blocking layer and a metallic zinc layer, does not show any redox peaks. Therefore, an improvement in electrochemical stability can be observed. An increase in current is observed at relatively high potentials. This can be attributed to the increased conductivity of the coating due to the contribution of the zinc metallic layer.

[0162] 2. After heat treatment

[0163] After heat treatment, redox peaks are observed in Coating 1, Coating 7, and Coating 6, which means that the conductive coating is degraded.

[0164] This phenomenon is particularly pronounced in the case of coating 7, which has a zinc metal-based blocking layer alone: ​​an increase in current is observed above 3.4 V, and redox peaks are also observed at 3.6 and 3.7 V. The presence of the zinc metal layer alone does not improve the electrochemical stability of silver after heat treatment.

[0165] For coating 6, which has a blocking layer based on NiCr, the positive effect of this layer becomes relatively weaker in the case of heat treatment. In fact, although the increase around 3.4 V is small, a reduction peak at 3.6 V vs. Li+ / Li is observed, which corresponds to the degradation of silver.

[0166] The best results are obtained with the electroconductive coating of the invention, Inv. 4: neither a redox peak nor a voltage rise is observed at high potentials.

[0167] The combined effect of the blocking layer and the zinc metal layer shows a significant improvement in the electrochemical stability of silver: there is almost no current increase above 3.4 V and no redox peak.

[0168] The effects of the specific combination of inventions are superior to those of the individual components. The zinc metal blocking layer alone does not improve the electrochemical stability of silver. The NiCr blocking layer does not prevent the oxidation-reduction of the silver layer after heat treatment (above 500°C). Their combination reliably prevents the deterioration of the silver layer.

[0169] Combining a blocking layer with a metal layer of zinc that is diffusible and alloyable with silver improves the electrochemical stability of silver-based coatings above 3.7 V vs. Li / Li+ after heat treatment.

[0170] The present invention enables the use of silver-based coatings in high contrast electrochromic devices operating in the range of 2-4 V vs. Li / Li+.

Claims

1. 1. A material having a substrate coated with a first conductive coating, said first conductive coating comprising, starting from said substrate: a first dielectric coating, - metallic functional layers based on silver, a blocking layer, which is located in direct contact with the silver-based metallic functional layer and is chosen from metal layers, metal nitride layers, metal oxide layers and metal oxynitride layers based on metals or metal alloys of one or more elements chosen from titanium, nickel, chromium, tantalum and niobium, aluminum oxide layers and silicon oxide layers, at least one zinc- or indium-based metal layer located above or below the silver-based metal functional layer, in direct contact therewith or spaced apart by one or more layers having a total thickness of 20 nm or less; a second dielectric coating comprising at least one conductive oxide layer, the total thickness of said conductive oxide layers within said second dielectric coating being greater than 30 nm; A material having

2. The material of claim 1 , wherein the blocking layer has a thickness of 0.1 to 5.0 nm.

3. 3. The material according to claim 1, wherein the blocking layer is selected from a titanium nitride layer, a metal layer based on nickel and / or chromium, a nickel and / or chromium oxide layer, an aluminum oxide layer, a silicon oxide layer.

4. The material according to any one of claims 1 to 3, wherein the zinc or indium based metal layer is separated from the silver based metal functional layer by at least one blocking layer.

5. 5. The material according to claim 1, wherein all layers separating the silver-based metallic functional layer from the zinc- or indium-based metallic layer have a thickness of 10 nm or less.

6. The material according to any one of claims 1 to 5, wherein the thickness of the zinc or indium based metal layer is between 0.2 and 10 nm.

7. 7. The material of any one of claims 1 to 6, wherein the second dielectric coating comprises a conductive oxide layer selected from mixed oxides of tin and indium, tin-doped indium oxide, doped zinc oxide, doped ruthenium oxide, and fluorine-doped tin oxide.

8. 8. The material according to any one of claims 1 to 7, wherein the second dielectric coating comprises a conductive oxide layer selected from tin-indium mixed oxide or zinc oxide doped with aluminium and / or gallium.

9. The material according to any one of the preceding claims, wherein the second dielectric coating comprises a conductive oxide layer based on aluminium-doped zinc oxide having a thickness of more than 50 nm.

10. 10. The material according to any one of claims 1 to 9, wherein the first dielectric coating comprises at least one crystallized dielectric layer, in particular based on zinc oxide, optionally doped with at least one other element, such as aluminum.

11. The first dielectric coating is: nitrides or oxynitrides of silicon, aluminum and / or zirconium, and / or - layers based on zinc tin oxide, The material according to any one of claims 1 to 10, having

12. The material according to any one of the preceding claims, wherein the conductive coating is subjected to a heat treatment at a temperature above 300°C, preferably above 500°C.

13. The material of claim 12 , wherein the silver-based functional layer comprises zinc.

14. 1. An electrochromic system comprising: a material having a substrate coated with a first conductive coating, said first conductive coating being, starting from said substrate, one of the following: a first dielectric coating, - functional metal layers, including layers based on silver, a blocking layer, which is located in direct contact with the silver-based metallic functional layer and is chosen from metal layers, metal nitride layers, metal oxide layers and metal oxynitride layers based on metals or metal alloys of one or more elements chosen from titanium, nickel, chromium, tantalum and niobium, aluminum oxide layers and silicon oxide layers, at least one zinc-based metal layer located above or below the silver-based metal functional layer, either in direct contact therewith or spaced apart by one or more layers with a total thickness of 20 nm or less; a second dielectric coating having at least one conductive oxide layer, the total thickness of said conductive oxide layers within said second dielectric coating being greater than 30 nm; a material having a first active layer comprising an electrochromic material; an electrolyte layer; a second active layer, a second transparent electrically conductive coating, optionally a substrate, An electrochromic system comprising:

Images