MATERIAL COMPRISING A STACK WITH AN ABSORBENT METAL LAYER AND A DIELECTRIC OVERLAYER AND METHOD FOR DEPOSITING THIS MATERIAL

Abstract

The invention relates to a material comprising a substrate (30) coated on one face (29) with a stack of thin layers (14) comprising at least one metallic functional layer (140) and an antireflective coating (160) located above said functional layer (140) opposite said substrate (30) ends with: - a metallic layer (168), with a physical thickness of said metallic layer (168) which is between 1.0 and 8.0 nm, or even between 1.5 and 5.0 nm, or even between 1.8 and 2.5 nm; then - a dielectric overlayer (169) which is located on and in contact with said absorbing metallic layer (168). Abstract figure: Figure 1

Description

Title of the invention: MATERIAL COMPRISING A STACK WITH AN ABSORBENT METAL LAYER AND DIELECTRIC OVERLAYER AND METHOD FOR DEPOSITING THIS MATERIAL

[0001] The invention relates to a material comprising a substrate coated on one face with a stack of thin layers with reflection properties in the infrared and / or in solar radiation comprising at least one metallic functional layer, in particular based on silver or a metallic alloy containing silver and at least two anti-reflective coatings, said anti-reflective coatings each comprising at least one dielectric layer, said functional layer being arranged between the two anti-reflective coatings.

[0002] In this type of stack, the single, or each, metallic functional layer is thus arranged between two anti-reflective coatings, each generally comprising several layers which are each made of a dielectric material of the nitride type, and in particular silicon or aluminum nitride, or oxide. From an optical point of view, the purpose of these coatings which surround the or each metallic functional layer is to “antireflect” this metallic functional layer.

[0003] It is known from international patent application No. WO 2010 / 142926 to apply a radiation treatment after the deposition of a stack comprising a functional layer to reduce the emissivity or improve the optical properties of this stack, in particular by providing an absorbent layer in the terminal layer of the stack. The use of an absorbent terminal layer makes it possible to increase the absorption of radiation by the stack and to reduce the power required for the treatment. As the terminal layer oxidizes during the treatment and becomes transparent, the optical characteristics of the stack after treatment are interesting (high light transmission can in particular be obtained).

[0004] This radiation treatment of the stack does not structurally modify the substrate.

[0005] It is also known from international patent application No. WO 2016 / 051069 to apply a radiation treatment after the deposition of a stack comprising a metallic terminal layer consisting of zinc and tin, in SnxZny with a ratio of 0.1 < x / y < 2.4 and having a physical thickness of between 0.5 nm and 5.0 nm excluding these values.

[0006] The treatments are generally carried out by scrolling the substrate in an enclosure. It is desirable that the substrate passes as quickly as possible because the productivity of The line increases with speed, but this speed must not be too high for the treatment to actually produce the desired effect. In addition, too slow a speed can damage the thin-film stack.

[0007] The invention is based on the discovery of a particular configuration of two layers terminating the stack opposite the substrate which makes it possible to reduce the resistance per square measured after treatment at the same speed of radiation treatment of the stack according to known techniques, or to increase the speed of radiation treatment of the stack according to known techniques while retaining the resistance per square measured after treatment.

[0008] An aim of the invention is thus to succeed in developing a new type of stack of layers with one or more functional layers, a stack which has, after rapid treatment of the stack by radiation, a low resistance per square (and therefore a low emissivity), a high light transmission, as well as a high mechanical durability.

[0009] In the particular configuration according to the invention, it is proposed to finish the stack, opposite the face of the substrate which carries it, with two layers: a metallic, absorbent layer, then a dielectric overlayer comprising oxygen so that this dielectric overlayer can both: - constitute an oxygen reservoir to allow the oxidation of the absorbent metal layer located just below during heat treatment; - contribute to the mechanical durability of the stack; - and contribute to obtaining high light transmission, as well as to obtaining uniformity of appearance, both in transmission and in reflection.

[0010] The invention thus relates, in its broadest sense, to a material comprising a glass substrate coated on one face with a stack of thin layers with reflection properties in the infrared and / or in solar radiation comprising at least one, or even a single, metallic functional layer, in particular based on silver or a metallic alloy containing silver and at least two anti-reflective coatings, said anti-reflective coatings each comprising at least one dielectric layer, said functional layer being arranged between the two anti-reflective coatings, said material being remarkable in that said stack, opposite said substrate, ends starting from the substrate by: - an absorbent metal layer, with a physical thickness of said metal layer which is between 1.0 and 8.0 nm, or even between 1.5 and 5.0 nm, or even between 1.8 and 2.5 nm; then - a dielectric overlayer comprising oxygen, which is located on and in contact with said absorbing metal layer with a physical thickness of said dielectric overlayer which is between 1.5 and 40.0 nm, or even between 2.6 and 35.0 nm, or even between 5.6 and 30.0 nm.

[0011] Said dielectric overlayer is thus located on and in contact with said absorbent metal layer and the stack does not comprise any other layer further from the surface of the substrate than said dielectric overlayer comprising oxygen.

[0012] Said dielectric overlayer comprising oxygen preferably has a physical thickness which is between 5.6 and 25.0 nm, or even between 6.6 and 20.0 nm, or even between 7.6 and 15.0 nm, in order to increase mechanical durability.

[0013] Said absorbent metal layer preferably comprises at least one element chosen from Sn, Zn, Ti, In, Nb; it may be made of Sn, or Zn or Ti, or In, or Nb or a mixture of Sn and Zn, or a mixture of Sn and In.

[0014] Said dielectric overlayer preferably comprises at least one element chosen from Sn, Zn, Ti, Si, Zr.

[0015] Preferably, said dielectric overlayer does not comprise nitrogen in order to maximize the oxidation effect on the absorbent metal layer during treatment.

[0016] In a variant, this dielectric overlayer is made of an oxide having a composition which is the stable stoichiometry of the metallic element present or of the metallic elements present if there are several. It can be for example TiO2, ZrO2, SiO2, ZnO, SnO2.

[0017] In another variant, this dielectric overlayer is made up of an oxide having a composition which is over-stoichiometric in oxygen compared to the stable stoichiometry of the metallic element present or of the metallic elements present if there are several. It can be for example made of TiOx, ZrOx, SiOx, SnOx, with x > 2.

[0018] Preferably, this dielectric overlayer is not made of an oxide having a composition which is substoichiometric in oxygen relative to the stable stoichiometry of the metallic element present or of the metallic elements present if there are several.

[0019] In a variant, said anti-reflective coating located under said metallic functional layer and / or said anti-reflective coating located above said metallic functional layer comprises a dielectric layer comprising nitrogen, preferably a silicon-based nitride dielectric layer.

[0020] Preferably, said anti-reflective coating located under said functional layer comprises, in the direction of said substrate: - a zinc-based oxide sub-layer, ZnO, which is located under and in contact with said functional layer, with a physical thickness of said zinc-based oxide sub-layer ZnO which is between 0.3 and 9.0 nm, or even between 1.0 and 7.0 nm, or even between 1.5 and 5.0 nm; and

[0021] - a titanium-based oxide dielectric sub-layer, TiO2, which is located under and in contact with said zinc-based oxide sub-layer ZnO, with a physical thickness of said titanium-based oxide sub-layer, TiO2, which is between 10.0 and 50.0 nm, or even between 15.0 and 45.0 nm, or even between 20.0 and 45.0 nm.

[0022] Preferably, said anti-reflective coating located above said functional comprises, opposite said substrate and under said absorbent metal layer: - a zinc-based oxide layer, ZnO, with a physical thickness of said zinc-based oxide layer ZnO which is between 2.0 and 10.0 nm, or even between 2.0 and 8.0 nm, or even between 2.5 and 5.4 nm; and - a silicon-based nitride dielectric layer, Si3N4.

[0023] In a specific variant, said anti-reflective coating located above said functional layer further comprises a dielectric intermediate layer located between said zinc-based oxide ZnO overlayer and said silicon-based nitride dielectric layer, this dielectric intermediate overlayer being oxidized and preferably comprising a titanium oxide.

[0024] Said stack comprises a single metal functional layer or may comprise two metal functional layers, or three metal functional layers, or four metal functional layers; the metal functional layers in question here are continuous layers.

[0025] Said metal functional layer, or each metal functional, preferably has a physical thickness which is between 7.2 and 22.0 nm, or even between 9.0 and 16.0 nm, or even between 10.6 and 14.4 nm, or even between 9.5 and 12.4 nm. The range of 7.2 and 9.5 nm, or even 7.2 and 8.5 nm may be particularly suitable for a stack with a single metal functional layer and high light transmission.

[0026] A metallic functional layer preferably comprises, predominantly, at least 50% in atomic percentage, at least one of the metals chosen from the list: Ag, Au, Cu, Pt; one, several, or each metallic functional layer is preferably made of silver.

[0027] By “metal layer” in the sense of the present invention, it is to be understood that the formulation of the composition of the layer does not include oxygen or nitrogen.

[0028] By "absorbent layer" within the meaning of the present invention, it is to be understood that the layer is a material having an n / K ratio over the entire visible wavelength range (from 380 nm to 780 nm) between 0 and 5 excluding these values ​​and having an electrical resistivity in the bulk state (as known in the literature) greater than 10 5 Q.cm.

[0029] It is recalled that n denotes the real refractive index of the material at a given wavelength and k represents the imaginary part of the refractive index at a given wavelength; the ratio n / k being calculated at a given wavelength identical for n and for k.

[0030] By "metallic absorbent layer" within the meaning of the present invention, it is understood that the layer is absorbent as indicated above and that the formulation of the composition does not contain an oxygen atom or a nitrogen atom.

[0031] As usual, by "dielectric layer" in the sense of the present invention, it is to be understood that from the point of view of its nature, the layer is "non-metallic", that is to say that it comprises oxygen or nitrogen, or even both. In the context of the invention, this term means that the material of this layer has an n / k ratio over the entire visible wavelength range (from 380 nm to 780 nm) equal to or greater than 5.

[0032] It is recalled that n designates the real refractive index of the material at a given wavelength and the coefficient k represents the imaginary part of the refractive index at a given wavelength, or absorption coefficient; the ratio n / k being calculated at a given wavelength identical for n and for k.

[0033] For the purposes of the invention, “in contact” means that no layer is interposed between the two layers considered.

[0034] By "based on" is meant in the sense of the invention that for the composition of this layer, the reactive elements oxygen, or nitrogen, or both if they are both present, are not considered and the non-reactive element (for example silicon or zinc) which is indicated as constituting the base, is present at more than 85 atomic % of the total of the non-reactive elements in the layer. This expression thus includes what is commonly called in the art considered "doping", whereas the doping element, or each doping element, can be present in an amount of up to 10 atomic %, but without the total dopant exceeding 15 atomic % of the non-reactive elements.

[0035] In a particular variant, said antireflective coating located under said functional layer does not comprise any layer in the metallic state. Indeed, it is not desired for such a layer to be able to react at this location, and in particular to oxidize, during treatment.

[0036] In a particular variant, said anti-reflective coating located under said functional layer does not comprise any absorbent layer. Indeed, it is not desired for such a layer to be able to react at this location, and in particular to oxidize, during treatment.

[0037] It is all the more surprising to achieve the properties targeted by the invention for these two previous variants because similar properties are sometimes obtained in the prior art with these two previous variants.

[0038] Preferably, said silicon-based nitride dielectric layer Si3N4 does not comprise zirconium.

[0039] Preferably, moreover, said silicon-based nitride dielectric layer Si3 N4 does not contain oxygen.

[0040] The present invention further relates to a multiple glazing unit comprising a material according to the invention, and at least one other glass substrate, the substrates being held together by a frame structure, said glazing unit providing a separation between an exterior space and an interior space, in which at least one interposed gas layer is arranged between the two substrates.

[0041] Each substrate may be clear or colored. At least one of the substrates in particular may be made of mass-colored glass. The choice of the type of coloring will depend on the level of light transmission and / or the colorimetric appearance desired for the glazing once its manufacture is complete.

[0042] A substrate of the glazing, in particular the substrate carrying the stack, may be curved and / or toughened after the stack has been deposited. It is preferable in a multiple glazing configuration for the stack to be arranged so as to be turned towards the side of the interposed gas blade.

[0043] The glazing may also be triple glazing consisting of three sheets of glass separated two by two by a gas layer. In a triple glazing structure, the substrate carrying the stack may be on face 2 and / or face 5, when it is considered that the incident direction of the sunlight passes through the faces in increasing order of their number.

[0044] The present invention also relates to a method for obtaining, or manufacturing, a material comprising a glass substrate coated on one face with a stack of thin layers with reflection properties in the infrared and / or in solar radiation comprising at least one, or even a single, metallic functional layer, in particular based on silver or a metallic alloy containing silver and two anti-reflective coatings, said anti-reflective coatings each comprising at least one dielectric layer, said functional layer being arranged between the two anti-reflective coatings, said method comprising the following steps, in order: - the deposition on one face of said substrate of a stack of thin layers with reflection properties in the infrared and / or in solar radiation comprising at least one, or even a single, metallic functional layer, in particular based on silver or a metallic alloy containing silver and at least two anti-reflective coatings, in order to form a material according to the invention, then - the treatment of said stack of thin layers using a source producing radiation and in particular infrared radiation, in order to treat the stack of thin layers as such.

[0045] Said treatment is preferably carried out in an atmosphere not comprising of oxygen.

[0046] The details and advantageous characteristics of the invention emerge from the following non-limiting examples, illustrated with the aid of the attached figures illustrating: - [Fig.l] illustrates a structure of a functional monolayer stack according to the invention, the functional layer being deposited directly on a blocking sub-layer and directly under a blocking over-layer, the stack being illustrated during treatment using a source producing radiation; - [Fig.2] illustrates double glazing incorporating a stack according to the invention; - [Fig.3] illustrates the resistance per square, in ohms per square, of certain examples of thin film stacks as a function of the substrate travel speed S in meters per minute during the treatment illustrated in [Fig.l]; - [Fig.4] illustrates the light absorption LA, in percent, of certain examples of thin-film stacks as a function of the substrate travel speed S in meters per minute during the treatment illustrated in [Fig.l]; and - [Fig.5] illustrates the light absorption LA, in percent, of certain examples of thin-film stacks as a function of the substrate travel speed S in meters per minute during the treatment illustrated in [Fig.l] and as a function of the thickness of the last layer of the stack and the pressure inside the deposition chamber of this layer.

[0047] In figures 1 and 2, the proportions between the thicknesses of the different layers or of the different elements are not strictly respected in order to facilitate their reading.

[0048] [Fig.l] illustrates a structure of a functional monolayer stack 14 according to the invention deposited on a face 11 of a transparent glass substrate 10, in which the single functional layer 140, in particular based on silver or a metal alloy containing silver, is arranged between two antireflection coatings, the underlying antireflection coating 120 located below the functional layer 140 in the direction of the substrate 30 and the overlying antireflection coating 160 arranged above the functional layer 140 opposite the substrate 30. These two antireflection coatings 120, 160, each comprise at least one dielectric layer 122, 128; 162, 164, 166, 169.

[0049] In [Fig.l], the functional layer 140 is located indirectly on the underlying antireflective coating 120 and indirectly under the overlying antireflective coating 160: there is an under-blocking layer 130 located between the underlying antireflective coating 120 and the functional layer 140 and an over-blocking layer 150 located between the functional layer 140 and the antireflective coating 160.

[0050] Such a stack of thin layers can be used in a multiple glazing 100 providing a separation between an exterior space ES and an interior space IS; this glazing may have a double glazing structure, as illustrated in [Fig.2]: this glazing is then made up of two substrates 10, 30 which are held together by a frame structure 90 and which are separated from each other by an interposed gas blade 15.

[0051] In [Fig.2], the incident direction of sunlight entering the building is illustrated by the double arrow, on the left.

[0052] However, it can also be envisaged that in this double glazing structure, one of the substrates has a laminated structure.

[0053] A first series of examples was produced on the basis of the stacking structure 14 illustrated in [Fig.l] with, starting from the surface 11 of the substrate 10, with a thickness of 4 mm, only the following layers, in this order: - a dielectric layer of titanium dioxide, TiO2 122 with a physical thickness of 24 nm, deposited from a titanium target in an atmosphere of 6.25% oxygen on the total of argon and oxygen and under a pressure of 2.103 mbar; - a zinc-based oxide layer, ZnO 128, with a physical thickness of 4 nm, deposited from a ZnO ceramic metal target, in an argon atmosphere and under a pressure of 2.103 mbar; - a metallic functional layer 140 based on silver, and more precisely here in silver, with a physical thickness of 13.5 nm, deposited from a silver metallic target, in an argon atmosphere and under a pressure of 8.103 mbar; - a 150 metallic, titanium overblocking layer, with a physical thickness of 0.7 nm, deposited from a titanium target, in an argon atmosphere and under a pressure of 8.103 mbar; - a zinc-based oxide dielectric layer, ZnO 162, with a physical thickness of 4.0 nm, deposited from a ZnO ceramic target, in an argon atmosphere and under a pressure of 2.103 mbar; - a dielectric layer of titanium dioxide, TiO2 164 with a physical thickness of 12 nm, deposited from a titanium target in an atmosphere of 6.25% oxygen on the total of argon and oxygen and under a pressure of 2.103 mbar; - a silicon-based nitride dielectric layer, Si3N4, 166 with a physical thickness of 25 nm, deposited from an aluminum-doped silicon target, 92% by weight of silicon and 8% by weight of aluminum in an atmosphere of 45% nitrogen on the total of nitrogen and argon and under a pressure of 2.103 mbar; - a metallic layer 168, absorbent, in SnxZny, with a physical thickness of 2 nm, deposited from a metallic target of 50% by weight of tin and 50% by weight of zinc in an argon atmosphere and under a pressure of 2.103 mbar.

[0054] The elements Sn and Zn each have a ratio 0 < n / k < 5 over the entire visible wavelength range and an electrical resistivity in the bulk state which is greater at 105 Q.cm.

[0055] Silver also exhibits a ratio 0 < n / k < 5 over the entire visible wavelength range, but its electrical resistivity in the bulk state is less than 105 Q.cm.

[0056] In this first series, the stack described in the preceding paragraph constitutes a reference (“Ref” in the figures); this reference is based on examples 2 and 3 of international patent application No. WO 2016 / 051069.

[0057] In this first series, an example 1 (“Ex. 1” in the figures) was produced, further comprising a dielectric overlayer 169, made of ZrO2, with a thickness of 10 nm, which is located on and in contact with the metallic absorbent layer 168 and which is deposited from a metallic zirconium target, in an atmosphere of 28.5% oxygen out of the total of argon and oxygen and under a pressure of 2.103 mbar.

[0058] [Fig.3] illustrates on the ordinate the resistance per square, Rsq, in ohms per square of the reference stack and of example 1 thus deposited, this resistance per square being measured after laser treatment.

[0059] This laser treatment consisted here of a scrolling of the substrate 10 at a speed S varying from 7 meters per minute to 13 meters per minute under a laser line 20 with a continuous beam with a wavelength of 973.1 nm, 0.06 mm wide, 11.20 mm long and with a total power of 453 W, with the laser line oriented almost perpendicular to the face 11 (with an inclination of 7°) and in the direction of the stack 14, that is to say by arranging the laser line above the stack, as visible in [Fig.l] (the right black arrow illustrating the orientation of the emitted light), at a distance of 114 mm from the face 11.

[0060] This curve shows that there is an advantage in using an overlayer of zirconium oxide 169 because the resistance per square of the stack tends to be lower in the usual speed range, from 7 to 12 m / minute.

[0061] Such a situation makes it possible, in a first approach, to increase the solar factor at constant functional layer thickness, or even, in a second approach, to reduce the thickness of the functional layer to further increase the solar factor without modifying the previously obtained square resistance.

[0062] [Fig.4] illustrates on the ordinate the light absorption, LA, in percent, of the reference stack and of example 1 thus deposited. Before the laser treatment, the light absorption LA of the reference was 24.5% and that of example 1 was 23.0%. The laser treatment caused the decrease in the light absorption LA and this decrease is greater for example 1 than for the reference, whatever the running speed. It is therefore possible to increase the running speed of the substrate, and thus increase productivity.

[0063] Three other examples were produced on the basis of the structure of the reference stack with, in addition, a dielectric overlayer 169, in ZrO2, which is located on and in contact with the metallic absorbent layer 168: - for example 2 (“Ex. 2” in the figures) with a thickness of 10 nm, and deposited from a zirconium metal target, in an atmosphere of 28.5% oxygen out of the total of argon and oxygen and under a pressure of 5.103 mbar; - for example 3 with a thickness of 2 nm, and deposited from a zirconium metal target, in an atmosphere of 28.5% oxygen out of the total of argon and oxygen and under a pressure of 2.103 mbar; - for example 4 with a thickness of 2 nm, and deposited from a zirconium metal target, in an atmosphere of 28.5% oxygen out of the total of argon and oxygen and under a pressure of 5.103 mbar.

[0064] All these examples have been subjected to the same laser treatment as previously,

[0065] [Fig.5] illustrates the light absorption LA of the reference and examples 1 and 2, measured as before. The light absorption of Example 2 is similar to that of Example 1, or even slightly lower for higher substrate running speeds. The resistance per square of Example 2 is otherwise identical to that of Example 1 at the same running speed.

[0066] Scratch resistance was tested using a “Scratch Hardness Test 413” test machine from ERICHSEN: a Van Laar hard metal tip with a diameter of 0.55 mm, equipped with a tungsten carbide tip and loaded with a weight, was moved over the substrate at a given speed. Visibility through the area tested by the tip was noted as a function of the load.

[0067] It was found on the one hand that for high loads of 3 Newtons and 5 Newtons, examples 1 to 4 all have a less visible scratch than the reference and on the other hand that examples 1 and 2 have a less visible scratch than that of examples 3 and 4.

[0068] The present invention is described in the foregoing by way of example. It is understood that a person skilled in the art is able to carry out different variants of the invention without departing from the scope of the patent as defined by the claims.

Claims

Claims

1. Material comprising a glass substrate (10), coated on one face (11) with a stack of thin layers (14) with reflection properties in the infrared and / or in solar radiation comprising at least one, or even a single, metallic functional layer (140), in particular based on silver or a metal alloy containing silver and at least two anti-reflective coatings (120, 160), said anti-reflective coatings each comprising at least one dielectric layer (128, 162), said functional layer (140) being arranged between the two anti-reflective coatings (120, 160), said material being for treatment of said stack of thin layers (14) using a source producing radiation and in particular infrared radiation, characterized in that said stack, opposite said substrate (30), ends starting from the substrate by: - ​​an absorbent metallic layer (168) comprising Sn and Zn,with a physical thickness of said absorbing metal layer (168) which is between 1.0 and 8.0 nm, or even between 1.5 and 5.0 nm, or even between 1.8 and 2.5 nm; then - a dielectric overlayer (169) comprising oxygen, which is located on and in contact with said absorbing metal layer (168) with a physical thickness of said dielectric overlayer (169) which is between 1.5 and 40.0 nm, or even between 2.6 and 35.0 nm, or even between 5.6 and 30.0 nm.,

2. The material of claim 1, wherein said metal functional layer (140) has a physical thickness that is between 7.2 and 22.0 nm, or even between 9.0 and 16.0 nm, or even between 10.6 and 14.4 nm.

3. Material according to claim 1 or 2, wherein said dielectric overlayer (169) comprising oxygen has a physical thickness which is between 5.6 and 25.0 nm, or even between 6.6 and 20.0 nm, or even between 7.6 and 15.0 nm.

4. Material according to any one of claims 1 to 3, wherein said dielectric overlayer (169) comprises at least one element chosen from Sn, Zn, Ti, Si, Zr.

5. A material according to any one of claims 1 to 4, wherein said dielectric overlayer (169) does not comprise nitrogen.

6. A material according to any one of claims 1 to 5, wherein said anti-reflective coating (120) located under said metallic functional layer (140) and / or said anti-reflective coating (160) located above said metallic functional layer (140) comprises a dielectric layer comprising nitrogen, preferably a silicon-based nitride dielectric layer.

7. Multiple glazing comprising a material according to any one of claims 1 to 6, and at least one other glass substrate (30), the substrates (10, 30) being held together by a frame structure (90), said glazing providing a separation between an exterior space (ES) and an interior space (IS), in which at least one interposed gas blade (15) is arranged between the two substrates.

8. Method for obtaining a material comprising a glass substrate (10) coated on one face (11) with a stack of thin layers (14) with reflection properties in the infrared and / or in solar radiation comprising at least one, or even a single, metallic functional layer (140), in particular based on silver or a metal alloy containing silver and two anti-reflection coatings (120, 160), said anti-reflection coatings each comprising at least one dielectric layer (128, 162), said functional layer (140) being arranged between the two anti-reflection coatings (120, 160), said method comprising the following steps, in order: - the deposition on one face (11) of said glass substrate (10), of a stack of thin layers (14) with reflection properties in the infrared and / or in solar radiation comprising at least one, or even a single, layer metallic functional (140),in particular based on silver or a metal alloy containing silver and at least two anti-reflective coatings (120, 160), in order to form a material according to any one of claims 1 to 6, then - the treatment of said stack of thin layers (14) using a source producing radiation and in particular infrared radiation.,

9. A method according to claim 8, wherein said treatment is carried out in an atmosphere not comprising oxygen.

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