EP3383813A1

EP3383813A1 - Susbtrate provided with a stack having thermal properties, comprising at least one nickel oxide layer

Info

Publication number: EP3383813A1
Application number: EP16819144.3A
Authority: EP
Inventors: Denis Guimard; Silvia MARIANI
Original assignee: Saint Gobain Glass France SAS; Compagnie de Saint Gobain SA
Current assignee: Saint Gobain Glass France SAS
Priority date: 2015-12-02
Filing date: 2016-12-01
Publication date: 2018-10-10
Also published as: CN108602717A; BR112018011070A2; CA3006339A1; CO2018006932A2; RU2018123317A3; US20200255329A1; RU2731597C2; WO2017093677A1; MX2018006764A; RU2018123317A; FR3044658B1; JP2019503894A; KR20180088432A; FR3044658A1

Abstract

The invention relates to a transparent substrate (30), the main face of which is provided with a stack of thin layers including at least one, or a single, functional metal layer (140) having reflection properties in the infrared and/or solar radiation ranges, in particular based on silver or metal alloy containing silver, and two anti-reflection coatings (120, 160), each comprising at least one dielectric layer (122, 126; 162, 168). The above-mentioned functional layer (140) is disposed between the two anti-reflection coatings (120, 160). The substrate is characterised in that at least one nickel oxide layer Ni_xO is located under or in contact with the functional layer (140) in the direction of the substrate (30), the physical thickness of said nickel oxide layer Ni_xO being at least 0.3 nm, or between 0.6 and 8.0 nm, or even between 1.0 and 5.0 nm.

Description

The invention relates to a transparent substrate, in particular a mineral rigid material such as glass, said substrate being coated with a stack of thin layers comprising a functional layer. metal type that can act on solar radiation and / or long-wave infrared radiation.

The invention relates more particularly to the use of such substrates for manufacturing thermal insulation and / or sun protection glazings. These glazings can be intended both to equip buildings and vehicles, especially in order to reduce the air conditioning effort and / or to prevent excessive overheating (so-called "solar control" glazing) and / or to reduce the amount of energy dissipated to the outside (so-called "low emissive" glazing) driven by the ever increasing importance of glazed surfaces in buildings and vehicle interiors.

These windows can also be integrated in glazing with special features, such as heated windows or electrochromic windows.

A type of layer stack known to give substrates such properties consists of a functional metallic layer with infrared reflection properties and / or solar radiation, especially a metallic functional layer based on silver or of metal alloy containing silver.

In this type of stack, the functional layer is thus disposed between two antireflection coatings each in general comprising several layers which are each made of a dielectric material of the nitride type and in particular silicon or aluminum nitride or of the oxide type. From an optical point of view, the purpose of these coatings which frame the functional metallic layer is to "antireflect" this metallic functional layer.

A blocking coating is however sometimes interposed between one or each antireflection coating and the functional metal layer, the blocking coating disposed under the functional layer in the direction of the substrate, protects it during a possible heat treatment at high temperature, the bending type and / or quenching and the blocking coating disposed on the functional layer opposite the substrate protects this layer from possible degradation during the deposition of the superior antireflection coating and during a possible high temperature heat treatment, of the bending and / or quenching type.

It is known, for example from European Patent Application No. EP 718,250, that a dielectric layer called "wetting" based on zinc oxide placed directly under a metallic functional layer based on silver, in the direction of carrier substrate, promotes the achievement of a suitable crystallographic state of the metal functional layer while having the advantage of being able to withstand a heat treatment at high temperature bending, quenching.

This document also discloses the favorable effect of the presence of a layer deposited in metallic form directly on and in contact with the functional layer based on silver for the protection of the functional layer during the deposition of the other layers above. and during the heat treatment at high temperature. Those skilled in the art know this type of layer under the generic name of "blocking layer" or "blocker".

It is further known from International Patent Application No. WO 2010/142926 various solutions for carrying out a flash heating in a stack of thin layers comprising one or more functional layers based on silver. . The flash heating treatment makes it possible to improve the quality of the metallic functional layer and thus to reduce the emissivity (which is directly related to the resistance per square) and the use of an absorbent intermediate layer makes it possible to increase the absorption of the stack during the treatment so that it is short but effective. As the absorbing intermediate layer becomes transparent during the treatment, the optical characteristics of the stack after treatment are interesting (a high light transmission can in particular be obtained).

The object of the invention is to overcome the drawbacks of the prior art, by developing a new type of stack of functional monolayer layers or functional multilayer layers, stack which has a reduced square resistance (and therefore a reduced emissivity), after (or) heat treatment (s) at high temperature of the bending and / or quenching and / or annealing and / or flash heating type.

It has been discovered that, surprisingly, the presence of a nickel oxide layer in such a stack has very favorable effects on the reduction of the resistance per square of the stack in the case where this layer in Nickel oxide is directly in contact and under a metallic silver-based functional layer. The object of the invention is therefore, in its widest sense, a transparent substrate according to claim 1. This substrate is provided on a main face with a stack of thin layers comprising at least one or even a single metallic functional layer. with reflection properties in the infrared and / or in solar radiation, in particular based on silver or metal alloy containing silver, and two anti-reflective coatings, said antireflection coatings each comprising at least one dielectric layer, said functional layer being disposed between the two antireflection coatings, at least one Ni _x O nickel oxide layer being located under and in contact with the functional layer in the direction of said substrate, with a physical thickness of said Ni _x O nickel oxide layer; at least 0.3 nm, even between 0.6 and 8.0 nm, or even between 1.0 and 5.0 nm.

By "metal layer" in the sense of the present invention, it should be understood that the layer comprises neither oxygen nor nitrogen.

By "coating" in the sense of the present invention, it should be understood that there may be a single layer or several layers of different materials inside the coating.

By "contact" is meant in the sense of the invention that no layer is interposed between the two layers considered.

For the purpose of the invention, the term "based on" means that the element or material thus designated is present at more than 50 atomic% in the layer under consideration.

Advantageously, the single functional layer (or layers) with infrared reflection properties and / or in the solar radiation, is (or are) a layer (or layers) ) continue.

In fact, according to the invention, the Ni _x O nickel oxide layer contains no element other than Ni and O. The material constituting this layer may be described as: "pure nickel oxide".

The expression "Ni _x O" refers to the fact that there may be Ν1ΊΟ1 but also that the constituent material of the layer may not have exactly this stable stoichiometry:

the material of the layer may be slightly over-stoichiometric to Ni, with for example a 0.8 <x <1 and in particular 0.8 <x <0.95 or

the material of the layer may be slightly under stoichiometric in Ni with for example a 1 <x <1, 2 and in particular 1, 05 <x <1, 2. In a particular variant, said Ni _x O nickel oxide layer has an x between 1, 2 and 0.5 or even between 0.9 and 0.6.

In a very particular variant, a layer based on zinc oxide is located below, towards said substrate, and in contact with said nickel oxide layer Ni _x O.

Preferably, a Nickel oxide layer Ni _y O is located above and in contact with, and / or is located beneath and in contact with, said Nickel Oxide Ni _x O layer, a Nickel Oxide layer. closer to said functional layer being then less oxidized than another layer of nickel oxide further away from said functional layer from the substrate. Indeed, a more oxidized nickel oxide layer is better blocker and a less oxidized nickel oxide layer is better light absorbing.

Preferably also, said underlying antireflection and antireflection coatings each comprise at least one dielectric layer based on silicon nitride, optionally doped with at least one other element, such as aluminum.

It is also possible for another Ni _x O nickel oxide layer to be in the stack, located on the functional layer and in contact with the functional layer, with a physical thickness of said Ni _x O nickel oxide layer. at least 0.3 nm, even between 0.6 and 8.0 nm, or even between 1.0 and 5.0 nm. The x is preferably the same for these two Ni _x O nickel oxide layers to facilitate deposition.

Otherwise, it is possible for a metal layer, in particular comprising nickel and chromium, to be situated on and in contact with the functional layer, with a physical thickness of said metal layer of at least 0.3 nm, or even between 0 , 6 and 8.0 nm, or even between 1.0 and 5.0 nm.

It is further possible for a Ni _x O nickel oxide layer to be located on said functional layer in the direction of the substrate, with the interposition of at least one layer or layer of a different material between said oxide layer. nickel Ni _x O and said functional layer, said Ni _x O nickel oxide layer preferably having a thickness between 0.3 and 10.0 nm, or even between 0.6 and 8.0 nm, or even between 1, 0 and 5.0 nm. This can also have a favorable influence on the crystallographic state of the metallic functional layer, and therefore the square resistance of the stack.

The stack may comprise a last layer ("overcoat" in English), that is to say a protective layer, This protective layer preferably has a physical thickness of between 0.5 and 10 nm.

The glazing according to the invention incorporates at least the carrier substrate of the stack according to the invention, optionally associated with at least one other substrate. Each substrate can be clear or colored. At least one of the substrates may be colored glass in the mass. The choice of the type of coloration will depend on the level of light transmission and / or the colorimetric appearance sought for the glazing once its manufacture is complete.

The glazing according to the invention may have a laminated structure, in particular associating at least two rigid substrates of the glass type with at least one thermoplastic polymer sheet, in order to present a glass-like structure / thin-film stack / sheet (s) / glass. The polymer may especially be based on polyvinyl butyral PVB, ethylene vinyl acetate EVA, PET polyethylene terephthalate, PVC polyvinyl chloride.

The glazing may furthermore have a structure of glass type / stack of thin layers / sheet (s) of polymer.

The glazings according to the invention are capable of undergoing heat treatment without damage for the stack of thin layers. They are therefore optionally curved and / or tempered.

The glazing may be curved and / or tempered by being constituted by a single substrate, the one provided with the stack. It is then a glazing called "monolithic". In the case where they are curved, in particular to form glazing for vehicles, the stack of thin layers is preferably on an at least partially non-flat face.

The glazing may also be a multiple glazing, including a double glazing, at least the carrier substrate of the stack can be curved and / or tempered. It is preferable in a multiple glazing configuration that the stack is disposed so as to be turned towards the interleaved gas blade side. In a laminated structure, the stack may be in contact with the polymer sheet.

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

When the glazing is monolithic or multiple type double glazing, triple glazing or laminated glazing, at least the carrier substrate of the stack can be curved or tempered glass, this substrate can be curved or hardened before or after the deposition of the stack.

Advantageously, the present invention thus makes it possible to produce a stack of functional metal monolayer thin layers or metal functional multilayer layers which has a lower square resistance after heat treatment, without adversely affecting the optical parameters of the stack.

The details and advantageous features of the invention emerge from the following nonlimiting examples, illustrated with the aid of the attached figures illustrating:

in FIG. 1, a functional monolayer stack according to the invention, the functional layer being deposited directly on a sub-blocking coating and directly under an over-blocking coating, the stack being illustrated during the treatment with the aid of a source producing radiation;

in FIG. 2, a double glazing solution incorporating a functional monolayer stack;

in FIG. 3, the hysteresis curve of the nickel oxide deposited from a metal target in the presence of oxygen;

in FIG. 4, the partial profile of the element Ni analyzed by SIMS for example 1 before heat treatment (4BHT) and after heat treatment (4AHT); and

in FIG. 5, the partial profile of the element Ni analyzed by SIMS for example 2 before heat treatment (5BHT) and after heat treatment (5AHT).

In Figures 1 and 2, the proportions between the thicknesses of the different layers or different elements are not rigorously respected to facilitate their reading. FIG. 1 illustrates a structure of a functional monolayer stack according to the invention deposited on a face 29 of a transparent glass substrate, in which the single functional layer 140, in particular based on silver or alloy metal containing silver, is disposed between two antireflection coatings, the underlying antireflection coating 120 located below the functional layer 140 towards the substrate 30 and the overlying antireflection coating 160 disposed above the functional layer. 140 opposite the substrate 30. These two anti-reflection coatings 120, 160 each comprise at least one dielectric layer 122, 126; 162, 168 and preferably each at least two dielectric layers: in each dielectric coating, a dielectric layer 126, 162, preferably based on zinc oxide which is closer to the functional layer 140 and a dielectric layer 122, 168 , preferably based on silicon nitride, further away from the functional layer 140.

Optionally, on the one hand, the functional layer 140 may be deposited directly on a sub-blocking coating 130 placed between the underlying antireflection coating 120 and the functional layer 140 and, on the other hand, the functional layer 140 may be deposited directly under an overblocking coating 150 disposed between the functional layer 140 and the overlying antireflection coating 160.

The layers of under and / or over-blocking, although deposited in metallic form and presented as being metal layers, are sometimes in practice oxidized layers because one of their functions (in particular for the over-blocking layer) is to oxidize during the deposition of the stack to protect the functional layer.

According to the invention, at least one layer of nickel oxide Ni _x O (the layer 135 in Table 1 below) is located under and in contact with the functional layer 140 towards said substrate 30, with a physical thickness of said Ni _x O 135 nickel oxide layer of at least 0.3 nm, even between 0.6 and 8.0 nm, or even between 1.0 and 5.0 nm.

When a stack is used in a multi-glazing unit 100 of double-glazed structure, as illustrated in FIG. 2, this glazing comprises two substrates 60, 30 which are held together by a frame structure 90 and which are separated from one another. The substrate 30, 60 respectively has an inner face 29, 61 in contact with the intervening gas blade 19, the other face 31, 59 of the substrate 30, 60 being in contact with the substrate. IS interior space, respectively the outer space ES.

The glazing thus makes a separation between an outer space ES and an interior space IS.

The stack can be positioned in face 3 (on the innermost sheet of the building by considering the incident sense of sunlight entering the building and on its face facing the gas blade).

FIG. 2 illustrates this positioning (the incident direction of the solar light entering the building being illustrated by the double arrow) in front of a stack of thin layers 35 positioned on an inner face 29 of the substrate 30 in contact with the spacer gas strip 19, the other face 31 of the substrate 30 being in contact with the interior space IS.

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

For all the examples below, the layer deposition conditions are:

The deposited layers can thus be classified in four categories:

i-layers of anti-reflective / dielectric material having a n / k ratio over the entire upper visible wavelength range at 5: Si ₃ N ₄ , ZnO;

metallic functional layers made of material with infrared reflection properties and / or solar radiation: Ag; Silver has been found to have a ratio of 0 <n / k <5 over the entire visible wavelength range, and its bulk electrical resistivity is less than 10 ^-6 O.cm;

iii-underblocking and overblocking layers for protecting the functional layer against a change in its nature during the depositing of the stack;

iv- nickel oxide layer Ni _x O and Ni _y O; Figure 3 illustrates the deposition conditions of these two layers.

It should be noted that a ceramic target in Ν1ΊΟ1 was also tested and led to results similar to those seen with the examples below.

In all the examples below, the stack of thin layers is deposited on a clear soda-lime glass substrate of a thickness of 4 mm of the Planiclear brand, distributed by the company SAINT-GOBAIN.

In Table 1, the column "No." indicates the number of the layer and the second column indicates the coating, in connection with the configuration of Figure 1; the third column indicates the deposited material for the layer of the first column.

In this Table 1, the substrate 30 is located under the layer 122 and the layers of the examples are located in the order indicated by the left column, from bottom to top starting from this substrate 30; the numbered layers in these tables which are not shown in Figure 1 are thus located in the examples in the same manner as indicated in Table 1.

In the example series of Table 2, for Examples 2 to 6, the nickel oxide layer 134 and / or 135 and / or 136 is in the underlying blocking coating 130 and is in contact with the metallic functional layer. 140.

The nickel oxide Ni _y O of the layer 134 or 136 is different from the nickel oxide Ni _x O of the layer 135: with reference to FIG. 3 which illustrates the hysteresis curve of the deposited nickel oxide from a metal target in an oxidizing atmosphere (the abscissa indicates the flow of oxygen, in sccm and the ordinate indicates the voltage across the target), the Ni _x O is deposited under normal conditions leading to an oxide rich in oxygen (in other words supe- stoichiometric in oxygen, or stoichiometric in oxygen, even slightly under stoichiometric in oxygen), whereas the Ni _y O is deposited under conditions leading to an oxide rich in Ni (in other words frankly under -stoichiometric oxygen). The use of Ni _y O leads to a higher light absorption. Ex. 1 2 3

R (Ω / square) 4.7 4.5 (-5%) 3.9 (-17%)

Abs (¾) 9.4 9.4 10.0

Table 2

In Table 2, the characteristics of the substrate coated with the stack presented consist in the measurement, after a quenching heat treatment at 650 ° C. for 10 minutes and then cooling:

for R, square resistance measured as usual with a four-point probe, in ohms per square, and

for Abs, the light absorption in the visible in%, measured according to the illuminant D65 2 °, opposite side to the main face of the substrate on which the stack of thin layers is deposited.

The value between parenthesis iniquity improvement (decrease) of the resistance per square compared to the reference that constitutes Example 1.

The difference between Example 6 and Example 2 is that in the context of Example 2 (as for the other examples), the nickel oxide layer Ni _x O 135 is deposited directly on a layer based on zinc oxide 126, while in the context of Example 6, the nickel oxide layer Ni _x O 135 is deposited directly on a layer 122 based on silicon nitride. It has been noticed that the square resistance of Example 6 is higher than that of Example 2 because this example 6 does not benefit from the favorable conditions obtained when the nickel oxide layer is deposited directly on a base layer. zinc oxide.

The heat treatment could have consisted in running the substrate 30 at a speed of 10 m / min under a laser line 8. For example, such a laser line can be 60 μιη wide and 25 W / mm power. with the laser line oriented perpendicular to the face 29 and towards the terminal layer of the stack, the one farthest from the face 29, that is to say by arranging the laser line (illustrated by the black right arrow ) above the stack and directing the laser towards the stack, as shown in Figure 1.

Other tests were carried out with a nickel oxide layer Ni _x O 135 with a thickness of 1 nm and gave similar results.

Other tests were performed with a silver metal functional layer with a thickness of 15 nm and gave similar results.

In an attempt to understand the surprising improvement in square resistance, the profile of the Ni element was analyzed by SIMS: for example 1, it is shown in FIG.

for example 2, it is shown in FIG.

The profile of the Ni element was analyzed both before heat treatment (curves 4 BHT and 5 BHT), and after a heat treatment at 650 ° C. for 10 minutes and then cooling in the open air until the temperature of the room of 20 ° C.

For these two figures, the abscissa exposes an arbitrary unit of time which makes it possible to locate the different layers, which are recalled by their reference number above the figures; the ordinate exposes an arbitrary unit of intensity.

Comparison of the curve 4BHT with the curve 4AHT shows that a significant amount of element Ni NiCr blocking layer 150 is no longer in this layer 150 after the heat treatment because the intensity of the Ni signal has very strongly lowered: this suggests that the constituent material of the blocking layer has migrated elsewhere due to the heat treatment.

The 5BHT curve shows the presence of Ni both in the blocking layer

150 and in the layer 135 of Ni _x O; Curve 5AHT suggests that the material constituting the blocking layer 150 has migrated through the wetting layer 140 into the Ni _x O layer 135 because of the heat treatment where it has been somehow trapped.

This trapping effect was also observed for a stack similar to Example 2 but with the only difference a blocking layer 150 not NiCr but Ti.

Furthermore, attempts have been made to try to understand whether the mode of deposition of the layer 135 Ni _x O, based on Example 2, could influence the improvements obtained. Indeed, a Ni _x O layer can be obtained:

i. either by sputtering a metal target, containing only Ni, in an atmosphere containing oxygen, or even in addition a neutral gas such as argon;

ii. or by spraying a so-called "ceramic" target, containing both Ni and oxygen, in an atmosphere containing a neutral gas such as argon, or even in addition to oxygen.

It was found that the silver XRD diffraction peak of the metal functional layer 140 according to <200> was more pronounced in case i; however, at a layer thickness of identical Ni _x O (5 nm), the improvement (decrease) of the resistance per square with respect to Example 1 is the same: - 5%. It has been found that a layer 135 of Ni _x O deposited in case i has the same effect as in case ii: it improves (decreases) the resistance per square with the same order of magnitude.

On the basis of Example 2, it was found that a 19 nm thick Ni _x O layer deposited in case i, further improved (decreased still further) the square resistance, with a decrease -28% compared to that of Example 1 after heat treatment; however, light absorption in the visible, Abs is then raised to 36% after heat treatment

It was also found that the resistivity of the Ni _x O deposited according to the case i above, before heat treatment was of the order of 190 μΩαη, a value close to that of ΓΙΤΌ (about 200 μΩ ^) and well higher than the resistivity of the silver used for the functional layer 140, which is of the order of 3 μΩ ^; after the heat treatment at 650 ° C. for 10 minutes, the resistivity of this same Ni _x O deposited according to the case i above was lowered to approximately 30 μΩ ^.

Finally, again on the basis of Example 2, two other thicknesses were tested for layer 135 in Ni _x O: 3 nm and 10 nm. The decrease of the resistance per square after the heat treatment was of the same order of magnitude as for Example 2: 5% compared with Example 1. The mechanical strength of Example 2 was tested and compared with that of example 1: it is also good, sometimes even better for heavy loads.

Due to the low square resistance obtained as well as the good optical properties (in particular light transmission in the visible), it is possible, moreover, to use the substrate coated with the stack according to the invention to achieve a transparent electrode substrate.

In general, the transparent electrode substrate may be suitable for any heated glazing, for any electrochromic glazing, any display screen, or for a photovoltaic cell (or panel) and in particular for a transparent photovoltaic cell backside.

The present invention is described in the foregoing by way of example. It is understood that the skilled person is able to achieve different variants of the invention without departing from the scope of the patent as defined by the claims.

Claims

1. Transparent substrate (30) provided on one main face with a thin film stack comprising at least one or even one functional layer (140) of metal with infrared reflection properties and / or solar radiation, in particular with respect to silver-containing metal or silver alloy base, and two antireflection coatings (120, 160), said antireflection coatings each having at least one dielectric layer (122, 126; 162, 168), said functional layer (140 ) being disposed between the two antireflection coatings (120, 160), characterized in that at least one Ni _x O nickel oxide layer (135) is located under and in contact with the functional layer (140) towards said substrate ( 30), with a physical thickness of said nickel oxide layer Ni _x O (135) of at least 0.3 nm, even between 0.6 and 8.0 nm, or even between 1.0 and 5.0 nm .

2. Substrate (30) according to claim 1, characterized in that said nickel oxide layer Ni _x O (135) has an x between 1, 2 and 0.5, or even between 0.9 and 0.6.

3. Substrate (30) according to claim 1 or 2, characterized in that a layer based on zinc oxide is located below and in contact with said nickel oxide layer Ni _x O (135).

4. Substrate (30) according to any one of claims 1 to 3, characterized in that a nickel oxide layer Ni _y O (134, 136) is located below and in contact with and / or below and at contacting said nickel oxide layer Ni _x O (135), a nickel oxide layer closest to said functional layer (140) being less oxidized than another layer of nickel oxide further away.

5. Substrate (30) according to any one of claims 1 to 4, characterized in that a layer of nickel oxide Ni _x O is located on and in contact with the functional layer (140), with a physical thickness of said Ni _x O nickel oxide layer of at least 0.3 nm, even between 0.6 and 8.0 nm, or even between 1.0 and 5.0 nm.

6. Substrate (30) according to any one of claims 1 to 4, characterized in that a metal layer, especially comprising nickel and chromium, is located on and in contact with the functional layer (140), with a physical thickness of said metal layer of at least 0.3 nm, even between 0.6 and 8.0 nm, or even between 1.0 and 5.0 nm.

7. Substrate (30) according to any one of claims 1 to 6, characterized in that a layer of nickel oxide Ni _x O is located on said functional layer (140) towards the substrate (30), with interposition at least one layer or layer of a different material between said Ni _x O nickel oxide layer and said functional layer (140), said Ni _x O nickel oxide layer preferably having a thickness between 0.3 and 10.0 nm, or even between 0.6 and 8.0 nm, or even between 1.0 and 5.0 nm.

8. Substrate (30) according to any one of claims 1 to 7, characterized in that said underlying antireflection coatings (20) and overlying antireflection (60) each comprise at least one dielectric layer (22, 66) based on silicon nitride, possibly doped with at least one other element, such as aluminum.

9. Glazing (100) incorporating at least one substrate (30) according to any one of claims 1 to 8, optionally associated with at least one other substrate.

10. Glazing (100) according to claim 9 mounted in monolithic or multiple glazing type double glazing or triple glazing or laminated glazing, characterized in that at least the carrier substrate of the stack is curved and / or tempered.

1 1. Use of the substrate according to any one of claims 1 to 8, for producing a transparent electrode of a heating glazing unit or an electrochromic glazing unit or of a lighting device or a display device or a panel photovoltaic.