EP2399306A1

EP2399306A1 - Transparent substrate for photonic devices

Info

Publication number: EP2399306A1
Application number: EP10705857A
Authority: EP
Inventors: Benoit Domercq; Philippe Roquiny; Daniel Decroupet
Original assignee: AGC Glass Europe SA
Current assignee: AGC Glass Europe SA
Priority date: 2009-02-19
Filing date: 2010-02-19
Publication date: 2011-12-28
Also published as: WO2010094775A1; JP5606458B2; JP2015028940A; JP2012518261A; EA201101212A1; US20110297988A1; CN102326274A

Abstract

Transparent substrate (1) for photonic devices, comprising a support (10) and an electrode (11), said electrode (11) comprising a stack comprising a single metallic conduction layer (112) and at least one coating (110) having properties for enhancing the light transmission through said electrode, said coating (110) having a geometric thickness at least greater than 3 nm and at most less than or equal to 200 nm, said coating (110) comprising at least one light-transmission enhancement layer (1101) and being located between the metallic conduction layer (112) and the support (10) on which said electrode (11) is deposited, such that the optical thickness T01 of the coating (110) provided with light-transmission enhancement properties and the geometric thickness TME of the metallic conduction layer (112) are linked through the equation: TME = TME_o + Bsin(p*TD1/TD1_0)/n3 support where TME_o, B and TD1_0 are constants with TME_o having a value lying in the range from 10.0 to 25.0 nm, B having a value lying in the range from 10.0 to 16.5 and TD1_0 having a value lying in the range from 23.9 nD1 nm to 28.3 nD1 nm where nD1 represents the refractive index of the light-transmission enhancement coating at a wavelength of 550 nm, nsupport represents the refractive index of the support at the 550 nm wavelength.

Description

Transparent substrate for photonic devices

The present invention is in the technical field of photonic devices.

The present invention relates to a transparent substrate for a photonic device, to the process for manufacturing the substrate as well as to the manufacturing process of the photonic device incorporating it. By photonic device is meant any type of device that can emit or collect light. Such devices are for example optoelectronic devices such as organic electroluminescent devices known by the acronym OLED (Organic Light Emitting Device) or light collecting devices such as organic photovoltaic cells also called solar cells. In particular, the invention relates to a transparent substrate for an organic electroluminescent device (OLED: Organic Light Emitting Device).

Organic electroluminescent devices are manufactured with a good internal light output. This yield is expressed in terms of internal quantum efficiency (EQI). The internal quantum efficiency represents the number of photons obtained by the injection of an electron. It is of the order of 85%, or even close to 100%, in known organic electroluminescent devices. However, the efficiency of these devices is clearly limited by the losses associated with interfacial reflection phenomena.

In general, an OLED device comprises at least one organic electroluminescent layer, a transparent conductive electrode generally made of indium tin doped oxide (ITO) and a transparent support supporting the electrode. The support is for example glass, in ceramic glass or polymeric film. The refractive indices of the various constituents of the OLED device are in the range 1.6-1.8 for the organic layers of the electroluminescent device, 1.6 to 2 for the ITO layer, 1.4 to 1.6 for the carrier substrate and 1.0 for outdoor air. Reflection losses (R) occur at interfaces and result in a decrease in external quantum efficiency (EQE). The external quantum efficiency is equal to the internal quantum efficiency minus the reflection losses.

Indium tin doped oxide (ITO) is the most widely used material in the realization of transparent electrode. However, the use unfortunately poses a number of problems. Indeed, indium resources are limited which will in the short term lead to an inevitable increase in the production cost of these devices. In addition, because of the resistivity of the ITO, it is essential to use a thick layer to obtain a sufficiently conductive electrode. The ITO being slightly absorbent, this causes problems of decrease of the transparency. In addition, the thick ITO is generally more crystalline, which increases the roughness of the surface, which must then sometimes be polished for use within organic electroluminescent devices. Furthermore, the indium present in organic electroluminescent devices tends to diffuse into the organic part of these devices causing a decrease in the life of these devices.

The document WO2008 / 029060 A2 discloses a transparent substrate, in particular a transparent glass substrate, comprising a multilayer electrode with a complex stack comprising a metal conductive layer but also the presence of a primer cumulating the barrier layer and antireflection layer properties. . This type of electrode makes it possible to obtain layers having a low resistivity and a transparency at least equal to the ITO electrode, these electrodes being advantageously used in the field of large surface light sources such as light panels. In addition, these electrodes make it possible to reduce or even eliminate the quantity of indium used during their production. However, the solutions proposed in the document WO2008 / 029060 A2, while using an antireflection layer in the form of a barrier layer, do not attempt to optimize the quantity of light emitted by an OLED device by limiting the losses associated with the phenomena of inter-facial reflection.

The first object of the present invention is to provide a transparent substrate for obtaining an increase in the amount of light transmitted through the substrate, in other words an increase in the amount of light emitted or converted by a device. photonics incorporating it for monochrome radiation. The term "monochrome" means that only one color (eg, red, green, blue, white, ...) is perceived by the eye without this light being monochromatic. In other words, monochromatic radiation refers to radiation covering a range of wavelengths. More specifically, it is a question of providing a transparent substrate making it possible to obtain an increase in the quantity of light emitted by an organic electroluminescent device incorporating it, and this for a monochromatic radiation.

The second object of the present invention is to provide a method of manufacturing a transparent substrate having improved light transmission.

The third object of the present invention is to provide a photonic device incorporating the transparent substrate. More particularly, it is a question of providing an organic electroluminescent device incorporating the transparent substrate, in particular an organic electroluminescent device emitting quasi-white light.

The invention relates to a transparent substrate for photonic devices comprising a support and an electrode, said electrode comprising a stack comprising a single conduction metal layer and at least one coating having properties for improving the transmission of light through said electrode, said coating having a geometric thickness at least greater than 3.0 nm and at most less than or equal to 200 nm, preferably less than or equal to 170 nm, more preferably less than or equal to 130 nm, said coating comprising at least one light transmissive enhancement layer and being located between the conduction metal layer and the support on which said electrode is deposited, characterized in that the optical thickness of the coating having properties for improving the transmission of light transmission of light, T ₀₁ , and the geometrical thickness of the conductive metal layer, T _ME , are connected by the relation:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

where T _{ME 0} , B and T _{01 0} are constants with T _{ME 0} having a value in the range of 10.0 to 25.0 nm, B having a value in the range of 10.0 to 16 , 5 and T _{01 0} having a value in the range of 23.9 * n _D1 to 28.3 * n _D1 nm with n _D1 representing the refractive index of the coating for improving the transmission of light to a wavelength of 550 nm, n _support represents the refractive index of the support at a wavelength of 550 nm. Preferably, the constants T _{ME 0} , B and T _{01 0} are such that T _{ME 0} has a value in the range from 11.5 to 22.5 nm, B has a value in the range from 12 to 15 and T _{01 0} has a value in the range of 24.8 * n _D1 to 27.3 * n _D1 nm. More preferably, the constants T _{ME 0} , B and T _{01 0} are such that T _{ME 0} has a value in the range from 12.0 to 22.5 nm, B has a value in the range from 12 to And T _{01 0} has a value in the range of 24.8 * n _D1 to 27.3 * n _D1 nm.

The advantage offered by the substrate according to the invention is that it makes it possible to obtain an increase in the quantity of light emitted or converted by a photonic device incorporating it, and this for a monochromatic radiation, more particularly the amount of light emitted in the case of an organic electroluminescent device (OLED). In addition, in the case of an organic electroluminescent device emitting white light, the substrate according to the invention can be used with any type of known layer stack constituting the organic part of the OLED emitting white light.

The substrate of the present invention will be considered as transparent when it will have a light absorption of at most 50%, or even at most 30%, preferably at most 20%, more preferably at most 10% in the wavelength range of visible light.

The substrate of the present invention comprises an electrode, said electrode being able to behave as an anode or, on the contrary, as a cathode depending on the type of device into which it is inserted.

By the term "a coating having properties for improving the transmission of light" is meant a coating whose presence in the stack constituting the electrode leads to an increase in the amount of light transmitted through the substrate, for example a coating having anti-reflective properties. In other words, a photonic device incorporating the substrate according to the invention emits or converts a larger amount of light with respect to a photonic device of the same nature but comprising a conventional electrode (for example: ITO) deposited on an identical support to that of the substrate according to the invention. More particularly, when the substrate is inserted into an organic electroluminescent device, the increase in the amount of light emitted is characterized by a greater luminance value and whatever the color of the emitted light.

The geometric thickness of the light transmission enhancement coating must have a thickness at least greater than 3 nm, preferably at least 5 nm, more preferably at least 7 nm, most preferably at least 10 nm. nm. For example, when the light transmission enhancement coating is based on zinc oxide, sub-stoichiometric zinc oxide with oxygen, ZnO _x , these zinc oxides being optionally doped or alloyed with tin, a thickness geometric coating improvement of the light transmission at least greater than 3 nm provides a metal conduction layer, including silver, having good conductivity. The geometric thickness of the coating for improving light transmission advantageously has a thickness less than or equal to 200 nm, preferably less than or equal to 170 nm, more preferably less than or equal to 130 nm, the advantage offered by such thicknesses. residing in the fact that the manufacturing process of said coating is faster.

According to a particular embodiment, the substrate according to the invention comprises a transparent support having a refractive index at least equal to 1.2, preferably at least 1.4, more preferably at least 1.5 at a refractive index. wavelength of 550 nm. The advantage of using a medium having a high refractive index is that it allows the equal substrate structure to increase the amount of light transmitted or emitted.

By the term "support" is also meant to designate not only the support as such but also any structure comprising the support and at least one layer of a material having a refractive index, n _mateπau , close to the index of refraction of the support, n _support , in other words | n _support -n _mateπau | ≤ 0.1. | n _support -n _mateπau | represents the absolute value of the difference between the refractive indices. As an example, a layer of silicon oxide deposited on a support of silicosodocalcic glass may be mentioned.

The function of the support is to support and / or protect the electrode. The support may be made of glass, rigid plastics material (for example: organic glass, polycarbonate) or flexible polymeric films (for example: polyvinyl chloride (PVC), polyethylene terephthalate (PET), Polypropylene (PP)). The support is preferably rigid.

When the support is a polymeric film, it preferably has a high refractive index, the refractive index of the support

( ⁿ _supPort ) having a value of at least 1.4, preferably at least 1.5, more preferably at least 1.6, most preferably at least 1.7. n _support represents the refractive index of the support at a wavelength of 550 nm The advantage offered by the use of a support having a high refractive index is that it allows the same electrode structure of increase the amount of light transmitted or emitted.

When the support is made of glass, for example a glass sheet, it preferably has a geometric thickness of at least 0.35 mm. By the terms "geometrical thickness" is meant the average geometrical thickness. The glasses are mineral or organic. The mineral glasses are preferred. Among these, the clear or colored silicosodocalcic glasses are preferred in the mass or on the surface. More preferably, they are extra clear silicosodocalcic glasses. The term extra-clear means a glass containing at most 0.020% by weight of the total Fe glass expressed in Fe ₂ O ₃ and preferably at most 0.015% by weight. Glass, because of its low porosity, provides the advantage of providing better protection against any form of contamination of a photonic device comprising the transparent substrate according to the invention. For reasons of cost, the refractive index of the glass, ⁿ _support , preferably has a value of between 1.4 and 1.6. More preferably, the refractive index of the glass at a value equal to 1.5 n _support represents the refractive index of the support at a wavelength of 550 nm.

According to a particular embodiment, the transparent substrate according to the invention is such that the support at a refractive index between

1, 4 and 1.6 at a wavelength of 550 nm and that the electrode is such that the optical thickness of the coating with properties for improving the transmission of light, T ₀₁ , and the geometrical thickness of the conductive metal layer, T _ME , are connected by the relation:

T _ME = T _ME _ _o + [B * sin (π * T _D1 / T _{D1 0} )] / (n _support ) ³

where T _{ME 0} , B and T _{01 0} are constants with T _{ME 0} having a value in the range of 10.0 to 25.0 nm, preferably 10.0 to 23.0 nm, B having a value in the range of 10.0 to 16.5 and T _{01 0} having a value in the range of 23.9 * n ₀₁ to 28.3 * n ₀₁ nm with n ₀₁ representing the refractive index of coating for improving the transmission of light at a wavelength of 550 nm, n _support represents the refractive index of the support at a wavelength of 550 nm. Preferably, the constants T _{ME 0} , B and T _{01 0} are such that T _{ME 0} has a value in the range from 10.0 to 23.0 nm, preferably from 10.0 to 22.5 nm, the most preferably from 11.5 to 22.5 nm, B has a value in the range of 11.5 to 15.0 and T _{01 0} has a value in the range of 24.8 * n ₀₁ to 27, 3 * n ₀₁ nm. More preferably, the constants T _{ME 0} , B and T _{01 0} are such that T _{ME 0} has a value in the range from 10.0 to 23.0 nm, preferably from 10.0 to 22.5 nm, the more preferably from 11.5 to 22.5 nm, B has a value in the range of 12.0 to 15.0 and T _{01 0} has a value in the range of 24.8 * n ₀₁ to 27 , 3 * n ₀₁ nm.

According to a particular embodiment, the transparent substrate according to the invention is such that the support has a refractive index equal to 1.5 at a wavelength of 550 nm and that the electrode is such that the optical thickness the coating with light-transmitting enhancement properties, T ₀₁ , and the geometrical thickness of the conductive metal layer, T _ME , are connected by the relation:

T _ME = T _ME _ _o + [B * sin (π * T _ol / T _{ol 0} )] / (n _support ) ³

where T _{ME 0} , B and T _{01 0} are constants with T _{ME 0} having a a value in the range of 10.0 to 25.0 nm, preferably 10.0 to 23.0 nm, B having a value in the range of 10.0 to 16.5 and T _{01 0} having a value in the range from 23.9 * n _D1 to 27.3 * n _D1 nm with n _D1 representing the refractive index of the coating for improving the transmission of light at a wavelength of 550 nm n _support represents the refractive index of the support at a wavelength of 550 nm. Preferably, the constants T _{ME 0} , B and T _{01 0} are such that T _{ME 0} has a value in the range from 10.0 to 23.0 nm, preferably from 10.0 to 22.5 nm, the most preferably from 11.5 to 22.5 nm, B has a value in the range of 11.5 to 15.0 and T _{01 0} has a value in the range of 24.8 * n ₀₁ to 27, 3 * n _D1 . More preferably, the constants T _{ME 0} , B and T _{01 0} are such that T _{ME 0} has a value in the range from 10.0 to 23.0 nm, preferably from 10 to 22.5 nm, most preferably from 11.5 to 22.5 nm, B has a value within the range of 12.0 to 15.0 and T _{01 0} has a value in the range of 24.8 * n ₀₁ to 27.3 * n ₀₁ nm.

According to a particular embodiment of the preceding mode, the transparent substrate according to the invention is such that the geometric thickness of the metal conduction layer is at least equal to 6.0 nm, preferably at least 8.0 nm, more preferably at least equal to 10.0 nm and at most equal to 22.0 nm, preferably at most 20.0 nm, more preferably at most equal to 18.0 nm and whose geometric thickness of the coating of improvement of the light transmission is at least equal to 50.0 nm, preferably at least equal to 60.0 nm and at most equal to 130.0 nm, preferably at most equal to 110.0 nm, more preferably at most equal at 90.0 nm.

According to a particular embodiment, the transparent substrate according to the invention is such that it comprises a support having a refractive index value in the range from 1.4 to 1.6 and is such that the thickness the geometric conduction metal layer is at least 16.0 nm, preferably at least 18.0 nm, more preferably at least equal to 20.0 nm and at most equal to 29.0 nm, preferably at most equal to 27.0 nm, more preferably at most equal to 25.0 nm and the geometric thickness of the improvement coating. the light transmission is at least 20.0 nm and at most equal to 40.0 nm. Surprisingly, the use of a thick conductive metal layer combined with an optimized thickness of the light transmission enhancement coating makes it possible to obtain photonic systems, more particularly OLEDs devices, having on the one hand a high luminance and secondly incorporating a substrate whose electrode has a surface resistance expressed in Ω / h lower.

According to another particular embodiment, the transparent substrate according to the invention is such that the electrode comprises a coating for improving the transmission of light comprising at least one additional crystallization layer, said crystallization layer being, with respect to the support, the layer furthest from the stack constituting said coating.

According to a preferred embodiment, the substrate according to the invention is such that the refractive index of the material constituting the coating for improving the transmission of light (n _D1 ) is greater than the refractive index of the support (n _support ) (n _D1 > n _support ), preferably n _D1 > 1.2 n _support , more preferably n _D1 > 1.3 n _support , most preferably n _D1 > 1.5 n _support . The refractive index of the material constituting the coating (n _D1 ) has a value ranging from 1.5 to 2.4, preferably ranging from 2.0 to 2.4, more preferably ranging from 2.1 to 2.4 to a wavelength of 550 nm. When the light transmission enhancement coating is made up of several layers, n _D1 is given by the relation:

where m represents the number of layers constituting the coating, n _x represents the refractive index of the material constituting the x ^th layer starting from the support, I _x represents the geometrical thickness of the x ^th layer, 1 _D1 represents the thickness geometric coating. The use of a material having a higher refractive index makes it possible to obtain a larger quantity of transmitted or transmitted light. The advantage offered is all the more important that the difference between the refractive index of the coating for improving the transmission of light and the refractive index of the support is high.

The material constituting at least one layer of the light transmission enhancement coating comprises at least one dielectric compound and / or at least one electrically conductive compound. By the term "dielectric compound" is meant at least one compound chosen from:

the oxides of at least one element selected from Y, Ti, Zr,

Hf, V, Nb, Ta, Cr, Mo, W, Ni, Zn, Ai, Ga, In, Si, Ge, Sn, Sb, Bi as well as the mixture of at least two of them;

the nitrides of at least one element selected from boron, aluminum, silicon, germanium and their mixture;

- silicon oxynitride, aluminum oxynitride

a silicon oxycarbide.

When present, the dielectric compound preferably comprises an yttrium oxide, a titanium oxide, a zirconium oxide, a hafnium oxide, a niobium oxide, a tantalum oxide, a zinc oxide, a tin oxide, aluminum oxide, aluminum nitride, silicon nitride and / or silicon oxycarbide.

By the term "conductor" is meant at least one compound chosen from:

the oxides under stoichiometric oxygen and the doped oxides of at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Zn, l 'Ai, Ga, In, Si, Ge, Sn, Sb, Bi and the mixture of at least two of them

the doped nitrides of at least one element selected from boron, aluminum, silicon, germanium and their mixture

doped Si oxycarbide,

Preferably, the dopants comprise at least one of the elements chosen from Al, Ga, In, Sn, P, Sb and F. In the case of silicon oxynitride, the dopants comprise B , Ai and / or Ga.

Preferably, the conducting compound comprises at least the ITO and / or the doped Sn oxide, the dopant being at least one element chosen from F and Sb, and / or doped Zn oxide, the dopant being at least an element selected from Al, Ga, Sn, Ti. According to a preferred embodiment, the inorganic chemical compound comprises at least ZnO _x (with x ≤ 1) and / or Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6). Preferably, the Zn _x Sn _y O _z comprises at most 95% by weight of zinc, the weight percentage of zinc is expressed relative to the total weight of the metals present in the layer.

The conduction metal layer of the electrode forming part of the transparent substrate according to the invention mainly ensures the electrical conduction of said electrode. It comprises at least one layer comprising a metal or a mixture of metals. The generic term "metal mixture" refers to combinations of two or more metals in alloy form or doping of at least one metal with at least one other metal; the metal and / or the metal mixture comprising at least one element selected from Pd, Pt, Cu, Ag, Au, Al. Preferably, the metal and / or the mixture of metals comprises at least one element selected from Cu, Ag, Au, Al. More preferentially, the metallic conduction layer comprises at least Ag in pure form or alloyed with another metal. Preferably, the other metal comprises at least one element selected from Au, Pd, Al, Cu, Zn, Cd, In, Si, Zr, Mo, Ni, Cr, Mg, Mn, Co, Sn. More preferably, the other metal comprises at least Pd and / or Au, preferentially Pd.

According to a particular embodiment, the improvement coating of the light transmission of the electrode constituting a part of the substrate according to the invention comprises at least one additional crystallization layer, said crystallization layer being, with respect to the support, the layer furthest from the stack constituting said coating. This layer allows a preferential growth of the metal layer, for example silver, constituting the metal conduction layer and thereby obtain good electrical and optical properties of the metal conduction layer. It comprises at least one inorganic chemical compound. The inorganic chemical compound constituting the crystallization layer does not necessarily have a high refractive index. The inorganic chemical compound comprises at least ZnO _x (with x ≤ 1) and / or Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6). Preferably, the Zn _x Sn _y O _z comprises at most 95% by weight of zinc, the weight percentage of zinc is expressed relative to the total weight of the metals present in the layer. Preferably, the crystallization layer is ZnO. Since the layer having the property of improving light transmission has a thickness generally greater than that usually encountered in the field of conductive multilayer coatings (for example: low emissive type coating), the thickness of the crystallization layer must be be adapted and augmented to provide a conductive metal layer having good conduction and very little absorption.

According to a particular embodiment, the thickness The geometric thickness of the crystallization layer is at least equal to 7% of the total geometric thickness of the light transmission enhancement coating, preferably at 11%, more preferably at 14%. For example, in the case of a light transmission enhancement coating comprising a light transmissive enhancement layer and a crystallization layer, the geometric thickness of the light transmissive enhancement layer must be reduced if the geometric thickness of the crystallization layer is increased so as to respect the relationship between the geometrical thickness of the conduction metal layer and the optical thickness of the light transmission enhancement coating.

According to a particular embodiment, the crystallization layer is merged with at least one light transmission enhancement layer constituting the light transmission enhancement coating.

According to a particular embodiment, the light transmission enhancement coating comprises at least one additional barrier layer, said barrier layer being with respect to the support the layer closest to the stack constituting said coating. This layer makes it possible in particular to protect the electrode against any pollution by migration of alkali from the support, for example of silicosodocalcic glass, and therefore an extension of the lifetime of the electrode. The barrier layer comprises at least one compound selected from:

titanium oxide, zirconium oxide, aluminum oxide, yttrium oxide and the mixture of at least two of them;

the mixed oxide of zinc-tin, zinc-aluminum, zinc-titanium, zinc-indium, tin-indium;

silicon nitride, silicon oxynitride, silicon oxycarbide, silicon oxycarbonitride, aluminum nitride, oxynitride aluminum and the mixture of at least two of them;

this barrier layer being optionally doped or alloyed with tin.

According to a particular embodiment, the barrier layer is merged with at least one light transmission enhancement layer constituting the light transmission enhancement coating.

According to a preferred embodiment of the barrier and crystallization layers, at least one of these two additional layers is merged with at least one layer for improving the light transmission of the coating for improving the transmission of light.

According to a particular embodiment, the transparent substrate according to the invention is such that the electrode which constitutes it in part comprises a thin layer of uniformity of the electrical surface properties located, with respect to the support, at the top of the stack. multilayer constituting said electrode. The main function of the thin film of uniformity of surface electrical properties is to enable a uniform charge transfer to be obtained over the entire surface of the electrode. This uniform transfer results in an equivalent emitted or converted light flux at any point on the surface. It also increases the life of photonic devices since this transfer is the same at each point, eliminating possible hot spots. The uniformization layer has a geometric thickness of at least 0.5 nm, preferably at least 1.0 nm. The uniformization layer has a geometric thickness of at most 6.0 nm, preferably at most 2.5 nm, more preferably at most 2.0 nm. More preferably, the uniformization layer is equal to 1.5 nm. The uniformization layer comprises at least one layer comprising at least one inorganic material selected from a metal, a nitride, an oxide, a carbide, an oxynitride, an oxycarbide, a carbonitride or an oxycarbonitride.

According to a first particular embodiment of the mode previous, the inorganic material of the uniformization layer comprises a single metal or a mixture of metals. The generic term "metal mixture" refers to combinations of two or more metals in the form of an alloy or a doping of at least one metal with at least one other metal. The uniformization layer comprises at least one element selected from Li, Na, K, Be, Mg, Ca, Ba, Sc, Y, Ti, Zr, Hf, Ce, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, B, Al, Ga, In, Tl, C, Si, Ge, Sn, Pb. Metal and / or the mixture of metals comprises at least one element selected from Li, Na, K, Mg, Ca, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Si, C. More preferably, the metal or the mixture of metals comprises at least one element selected from C, Ti, Zr, Hf, V, Nb, Ta, Ni, Cr , Al, Zn. The metal mixture preferably comprises Ni-Cr and / or Zn doped with Al. The advantage offered by this particular embodiment is that it makes it possible to obtain the best possible compromise between, on the one hand, the electrical properties resulting from the effect of the uniformity layer of the surface electrical properties and, on the other hand, the optical properties obtained through the improvement coating. The use of a uniformization layer having the lowest possible thickness is fundamental. Indeed, the influence of this layer on the amount of light emitted or converted by the photonic device is even lower than its thickness is low. This uniformization layer when it is metallic is thus distinguished from the conduction layer by its thinner thickness, this thickness being insufficient to ensure a conductivity. Thus, the uniformization layer when it is metallic, that is to say composed of a single metal or mixture of metals, preferably has a geometric thickness of at most 5.0 nm.

According to a second particular embodiment, the inorganic material of the uniformization layer is present in the form of at least one chemical compound selected from carbides, carbonitrides, oxynitrides, oxycarbides, oxycarbonitrides and mixtures of at least two of them. Oxynitrides, oxycarbides, oxycarbonitrides of the uniformization layer may be in non-stoichiometric form, preferably substoichiometric with respect to oxygen. The carbides are carbides of at least one element selected from Be, Mg, Ca, Ba, Sc, Y, Ti, Zr, Hf, Ce, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co , Rh, Ir, Ni, Pd, Pt, Cu, Au, Zn, Cd, B, Al, Si, Ge, Sn, Pb, preferably of at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Pd, Pt, Cu, Au, Zn, Cd, Al, Si, more preferably at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Ni, Cr, Zn, Al. Carbonitrides are carbonitrides of at least one element selected from Be, Sc, Y, Ti, Zr, Hf, V, Nb, Cr, Mo, W, Fe, Co, Zn , B, Al, Si, preferably at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Co, Zn, Al, Si, more preferably at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Zn, Al. The oxynitrides are oxynitrides of at least one element selected from Be, Mg, Ca, Sr, Sc, Y, Ti, Zr, Hf , V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Rh, Ir, Ni, Cu, Au, Zn , B, Al, Ga, In, Si, Ge, preferably of at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Cu, Au, Zn, Al, Si, more preferably at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Zn, Al. The oxycarbides are oxycarbures of at least one element selected from Be, Mg , Ca, Sr, Sc, Y, Ti, Zr, Hf, V, Nb, Cr, Mo, W, Mn, Fe, Ni, Zn, Si, Ge, preferably of at least one element selected from Ti, Zr, Hf, V, Nb, Cr, Mo, W, Mn, Ni, Zn, Al, Si, more preferably at least one element selected from Ti, Zr, Hf, V, Nb, Cr, Zn, Al. Oxycarbonitrides are oxycarbonitrides of at least one element selected from Be, Ti, Zr, Hf, V, Nb, Cr, Mo, W, Mn, Zn, B, Al, Si, Ge, preferably at least one element selected from Ti, Zr, Hf, V, Nb, Cr, Mo, W, Mn, Zn, Al, Si, more preferably at least one element selected from Ti, Zr, Hf, V, Nb, Cr, Zn, Al. The C arbures, carbonitrides, oxynitrides, oxycarbides, oxycarbonitrides of the uniformity layer of the surface electrical properties optionally comprise at least one doping element. In a preferred embodiment, the thin uniformization layer comprises at least one oxynitride comprising at least one element selected from Ti, Zr, Cr, Mo, W, Mn, Co, Ni, Cu, Au, Zn, Al, Si. More preferably, the thin film of uniformity of the surface electrical properties comprises at least one oxynitride chosen from Ti oxynitride, Zr oxynitride and oxynitride. Ni, NiCr oxynitride.

According to a third particular embodiment, the inorganic material of the uniformization layer is present in the form of at least one metal nitride of at least one element selected from Be, Mg, Ca, Sr, Ba, Sc, Y , Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, B , Al, Ga, In, Si, Ge, Sn. Preferably, the uniformization layer comprises at least one nitride of an element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Co, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Si. More preferably, the nitride comprises at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Ni, Cr, Al, Zn. More preferably, the thin film of uniformity of the surface electrical properties comprises at least Ti nitride, Zr nitride, Ni nitride, NiCr nitride.

According to a fourth particular embodiment, the inorganic material of the uniformization layer is present in the form of at least one metal oxide of at least one element selected from Be, Mg, Ca, Sr, Ba, Sc, Y , Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, B , Al, Ga, In, Si, Ge, Sn, Pb. Preferably, the uniformization layer comprises at least one oxide of an element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W , Mn, Co, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, In, Si, Sn. More preferably, the oxide comprises at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Ni, Cu, Cr, Al, In, Sn, Zn. The oxide of the uniformization layer may be an oxide under stoichiometric oxygen. The oxide optionally comprises at least one doping element. Preferably, the doping element is selected from at least one of the elements selected from Al, Ga, In, Sn, Sb, F and Ag. More preferably, the thin film of uniformity of the surface electrical properties comprises at least the Ti oxide and / or the Zr oxide and / or the Ni oxide and / or the NiCr oxide and / or the ITO and / or the doped Cu oxide, the dopant being Ag, and / or the oxide doped Sn, the dopant being at least one element selected from F and Sb, and / or doped Zn oxide, the dopant being at least one element selected from A 1, Ga, Sn, Ti .

According to a particular embodiment, the transparent substrate according to the invention is such that the electrode which constitutes it in part comprises at least one additional insertion layer located between the conduction metal layer and the uniform thinning layer. The layer inserted between the conduction metal layer and the uniformization layer comprises at least one layer comprising at least one dielectric compound and / or at least one electrically conductive compound. Preferably, the insertion layer comprises at least one layer comprising at least one conductive compound. This insertion layer has the function of constituting part of an optical cavity making it possible to make the metal conduction layer transparent. By the term "dielectric compound" is meant at least one compound chosen from:

the oxides of at least one element selected from Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Zn, Al, Ga In, Si, Ge, Sn, Sb, Bi and the mixture of at least two of them,

the nitrides of at least one element selected from boron, aluminum, silicon, germanium and their mixture,

silicon oxynitride, aluminum oxynitride,

a silicon oxycarbide.

When present, the dielectric compound preferably comprises an yttrium oxide, a titanium oxide, a zirconium oxide, a hafnium oxide, a niobium oxide, a tantalum oxide, a zinc oxide, tin oxide, aluminum oxide, aluminum nitride, silicon nitride and / or silicon oxycarbide.

By the term "conductor" is meant at least one compound chosen from:

the stoichiometric oxygen oxides and the doped oxides of at least one element selected from Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Zn, Al, Ga, In, Si, Ge, Sn, Sb, Bi and the mixture of at least two of them,

the doped nitrides of at least one element selected from boron, aluminum, silicon, germanium and their mixture,

doped Si oxycarbide,

Preferably, the dopants comprise at least one of the elements chosen from Al, Ga, In, Sn, P, Sb, and F. In the case of silicon oxynitride, the dopants comprise B , Ai and / or Ga.

Preferably, the conducting compound comprises at least the ITO and / or the doped Sn oxide, the dopant being at least one element chosen from F and Sb, and / or doped Zn oxide, the dopant being at least an element selected from Al, Ga, Sn, Ti. According to a preferred embodiment, the inorganic chemical compound comprises at least ZnO _x (with x ≤

1) and / or Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6). Preferably, the Zn _x Sn _y O _z comprises at most 95% by weight of zinc, the weight percentage of zinc is expressed relative to the total weight of the metals present in the layer.

According to a particular embodiment of the preceding mode, the transparent substrate according to the invention is such that the geometric thickness of the insertion layer (E _1n ) is such that, on the one hand, its ohmic thickness is at most equal at 10 ¹² Ohm, preferably at most equal to 10 ⁴ Ohm, the thickness ohmic being equal to the ratio between, on the one hand, the resistivity of the material constituting the insertion layer (p) and, on the other hand, the geometrical thickness of this same layer (1), and that on the other hand the geometrical thickness of the insertion layer is connected to the geometric thickness of the first organic layer of the organic electroluminescent device (E _org ), the terms first organic layer designating the set of organic layers between the insertion layer and the organic layer electroluminescent, by the relation: E _org = E _1n - A or A is a constant whose value is in the range from 5.0 to 75.0 nm, preferably from 20.0 to 60.0 nm, more preferably from 30.0 to 45.0 nm. The inventors have determined that, surprisingly, the relationship E _org = E _1n -A makes it possible to use the geometrical thickness of the first organic layer of the organic electroluminescent device to optimize the optical parameters (geometrical thickness and refractive index) of the layer insertion and thus optimize the amount of light transmitted while keeping a thickness of the insertion layer compatible with electrical properties to avoid high ignition voltages and for a first maximum luminance.

According to another particular embodiment, the transparent substrate according to the invention is such that the geometric thickness of the insertion layer (E _1n ) is such that, on the one hand, its ohmic thickness is at most equal to 10 ¹² Ohm, preferably at most equal to 10 ⁴ Ohm, the ohmic thickness being equal to the ratio between, on the one hand, the resistivity of the material constituting the insertion layer (p) and, on the other hand, the geometrical thickness of this same layer (1), and that on the other hand the geometric thickness of the insertion layer is related to the geometric thickness of the first organic layer of the organic electroluminescent device (E _org ), the terms first organic layer designating the together organic layers between the insertion layer and the organic electroluminescent layer, by the relation: E _org = E _1n - C or C is a constant whose value is in the range of 150.0 to 250.0 nm, preferably from 160.0 to 225.0 nm, more preferably from 75.0 to 205.0 nm. The inventors have determined that, surprisingly, the relationship E _org = E _1n -A makes it possible to use the geometrical thickness of the first organic layer of the organic electroluminescent device to optimize the optical parameters (geometrical thickness and refractive index) of the layer insertion and thus optimize the amount of light transmitted while keeping an insertion layer thickness compatible with electrical properties to avoid high ignition voltages and for a second maximum luminance.

According to another particular embodiment of the transparent substrate according to the invention, the metal conduction layer of the electrode comprises on at least one of its faces at least one sacrificial layer. By sacrificial layer is meant a layer that can be oxidized or nitrided in whole or in part. This layer makes it possible to avoid deterioration of the metallic conduction layer, in particular by oxidation or nitriding. In addition, although it may be located between the metal conduction layer and the crystallization layer, the presence of this sacrificial layer is compatible with the action of a crystallization layer. When present, the sacrificial layer comprises at least one compound chosen from metals, nitrides, oxides and sub-stoichiometric oxygen oxides. Preferably, the metals, nitrides, oxides and sub-stoichiometric metal oxides comprise at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Zn, Al. Preferably, the sacrificial layer comprises at least Ti, Zr, Ni, Zn, Al. Most preferably, the sacrificial layer comprises at least Ti, TiO _x (with x ≤ 2), NiCr, NiCrO _x , TiZrO _x (TiZrO _x indicates a layer of titanium oxide at 50% by weight d zirconium oxide), ZnAlO _x (ZnAlO _x indicates a layer of zinc oxide with 2 to 5% by weight of aluminum oxide). According to a particular embodiment of the preceding embodiment, the thickness of the sacrificial layer comprises a thickness at least 0.5 nm. The thickness of the sacrificial layer comprises a thickness of at most 6.0 nm. More preferably, the thickness is equal to 2.5 nm. According to a preferred embodiment, a sacrificial layer is deposited on the face of the metal conduction layer furthest from the support.

According to another particular embodiment, the transparent substrate according to the invention is such that the support on which said electrode is deposited comprises at least one functional coating. Preferably, said functional coating is located on the face opposite to the face on which the electrode according to the invention is deposited. This coating comprises at least one coating selected from an antireflective multilayer layer or stack, a diffusing layer, an anti-fog or antifouling layer, an optical filter, in particular a titanium oxide layer, a selective absorbing layer, a microlens system such as that, for example, those described in the article by Lin et al. in OPTICS EXPRESS, 2008, vol. 16, No. 15, pp 11044-11051 or in US2003 / 0020399 A1, page 6.

According to a preferred embodiment, the transparent substrate according to the invention essentially has the following structure from a clear or extra clear glass support:

• Coating for improving light transmission:

o TiO ₂ light transmission enhancement layer (confused with the barrier layer)

o ZnO or Zn _x Sn _y O _z crystallization layer (with x + y ≥ 3 and z ≤ 6)

• Ag conduction metal layer, the geometric thickness of the coating with light transmission enhancement properties and the geometric thickness of the metal layer of conduction are connected by the relation:

T _ME = T _ME _o + [B * sin (π * T _D1 / T _{D1 0} )] / (n _support ) ³

where T _{ME 0} , B and T _{01 0} are constants with T _{ME 0} having a value in the range of 10.0 to 25.0 nm, preferably 10.0 to 23.0 nm, B having a value in the range of 10.0 to 16.5 and T _{01 0} having a value in the range of 23.9 * n ₀₁ to 28.3 * n ₀₁ with n ₀₁ representing the refractive index of the coating for improving the transmission of light at a wavelength of 550 nm, π _support represents the refractive index of the support at a wavelength of 550 nm. Preferably, the constants T _{ME 0} , B and T _{01 0} are such that T _{ME 0} has a value in the range from 10.0 to 23.0 nm, preferably from 10.0 to 22.5 nm, the most preferably from 11.5 to 22.5 nm, B has a value in the range of 11.5 to 15.0 and T _{01 0} has a value in the range of 24.8 * n ₀₁ to 27, 3 * n ₀₁ nm. More preferably, the constants T _{ME 0} , B and T _{01 0} are such that T _{ME 0} has a value in the range from 10.0 to 23.0 nm, preferably from 10.0 to 22.5 nm, the more preferably from 11.5 to 22.5 nm, B has a value in the range of 12.0 to 15.0 and T _{01 0} has a value in the range of 24.8 * n ₀₁ to 27 , 3 * n ₀₁ nm.

• Sacrificial layer: geometric thickness 1.0-3.0 nm in Ti

• Insertion layer: geometrical thickness 3.0-20.0 nm in Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6)

• Standardization layer: geometric thickness 0.5-3.0 nm in X, nitride of X, oxynitride of X with X: Ti, Zr, Hf, V, Nb, Ta, Ni, Pd, Cr, Mo, Al , Zn, Ni-Cr or Zn doped with Al. According to a preferred embodiment, the transparent substrate according to the invention essentially has the following structure from the clear or extra clear glass support:

• Coating for improving light transmission:

o Layer of improvement of the light transmission in TiO ₂

(confused with the barrier layer)

o ZnO or Zn _x Sn _y O _z crystallization layer (with x + y ≥ 3 and z ≤ 6)

the geometric thickness of the coating for improving light transmission is at least 50.0 nm, preferably at least 60.0 nm, more preferably at least 70.0 nm and at most equal to 100 nm, preferably at most equal to 90.0 nm, more preferably at most equal to 80.0 nm,

• Ag conduction metal layer, the geometric thickness of the metal conduction layer is at least equal to 6.0 nm, preferably at least 8.0 nm, more preferably at least 10.0 nm and at least more than 22.0 nm, preferably at most 20.0 nm, more preferably at most 18.0 nm.

• Sacrificial layer: geometric thickness 1.0-3.0 nm in Ti

• Standardization layer: geometrical thickness 0.5-3.0 nm in X, nitride of X, oxynitride of X with X: Ti, Zr, Hf, V, Nb, Ta, Ni, Pd,

Cr, Mo, Al, Zn, Ni-Cr or Zn doped with Al.

• Coating for improving light transmission:

o ZnO or Zn _x Sn _y O _z crystallization layer (with x + y ≥ 3 and z ≤ 6)

the geometric thickness of the coating for improving light transmission is at least 20.0 nm and at most equal to 40.0 nm.

• Ag conduction metal layer, the geometric thickness of the metal conduction layer is at least 16.0 nm, preferably at least 18.0 nm, preferably at least 20.0 nm and at most equal to 29.0 nm, preferably at most equal to 27.0 nm, more preferably at most equal to 25.0 nm.

• Sacrificial layer: geometric thickness 1.0-3.0 nm in Ti

• Standardization layer: geometric thickness 0.5-3.0 nm in X, nitride of X, oxynitride of X with X: Ti, Zr, Hf, V, Nb, Ta, Ni, Pd, Cr, Mo, Al , Zn, Ni-Cr or Zn doped with Al.

According to a particular embodiment, the transparent substrate according to the invention is such that the reflection on the support side, r _support , in particular a glass support, has a value at least equal to 28% and at most equal to 49%

The embodiments of the transparent substrate are not limited to not to the modes described above but may also result from a combination of two or more of them.

The second subject of the invention concerns the process for manufacturing the transparent substrate according to the invention. This substrate comprises a support and an electrode. The process for producing the transparent substrate according to the invention is a process in which the uniformization layer and / or a set of layers comprising the electrode are deposited on the support. Examples of such processes are sputtering techniques, possibly assisted by a magnetic field, plasma deposition techniques, CVD (Chemical Vapor Deposition) and / or PVD (Physical Vapor Deposition) deposition techniques. Preferably, the deposition process is carried out under vacuum. The terms "under vacuum" refer to a pressure of less than or equal to 1.2 Pa. More preferably, the vacuum process is a magnetic field assisted sputtering technique. The method of manufacturing the transparent substrate comprises continuous processes in which any layer constituting the electrode is deposited immediately following the layer underlying it in the multilayer stack (for example: deposition of the stack constituting the electrode according to the invention on a support which is a ribbon scrolling or deposition of the stack on a support which is a panel). The manufacturing process also includes discontinuous processes in which a lapse of time (for example in the form of a storage) separates the deposition of a layer and the layer underlying it in the stack constituting the electrode.

According to a preferred embodiment, the method of manufacturing the transparent substrate according to the invention is such that it is produced in two stages decomposing in the following manner:

• deposit on the support of the coating having properties of improvement of the transmission of light, • deposition of the conduction metal layer, directly followed by the deposition of the various functional elements constituting the photonic system.

According to another preferred embodiment, the method of manufacturing the transparent substrate according to the invention is such that it is produced in two stages decomposing in the following manner:

Deposit on the support of the coating having properties for improving the transmission of light through the electrode, the conductive metal layer, the sacrificial layer, the insertion layer,

Deposit of the uniformization layer directly followed by the deposition of the various functional elements constituting the photonic system.

When the uniformization layer or the conductive metal layer are subsequently deposited, the organic part of the photonic device is deposited immediately after the deposition of the uniformization layer or of the metallic conduction layer, that is to say without venting the uniformization layer or the conduction metal layer prior to deposition of the organic portion of the photonic device. The advantage offered by these methods is that they make it possible to avoid oxidation of the conduction or uniformization layers when these consist of metal. According to a particular mode in the previous mode, the barrier layer is deposited (for example: by CVD) on a glass ribbon. The following layers of the stack, with / without the uniformization layer, are deposited under vacuum on said ribbon or on glass panels resulting from the cutting of said ribbon. The panels covered by the barrier layer obtained after cutting are optionally stored.

According to a particular mode of implementation, the uniformization layer of the electrical surface properties based on oxides and / or oxynitrides can be obtained by direct deposition. According to an alternative method, the oxidation and / or oxynitride-based uniformization layer may be obtained by oxidation of the corresponding metals and / or nitrides (for example: Ti is oxidized to Ti oxide, nitride of Ti is oxidized to Ti oxynitride). This oxidation can occur directly or long after the deposition of the uniformization layer. The oxidation can be natural (for example: an interaction with an oxidizing compound present during the manufacturing process or during the storage of the electrode before complete manufacture of the photonic device) or result from a post-treatment (for example: a treatment to ozone under ultraviolet).

According to an alternative mode of implementation, the method comprises an additional step of structuring the surface of the electrode. The structuring of the surface of the electrode is different from the structuring of the support. This additional step performs a modeling of the surface and / or an ornamentation of the surface of the electrode. The method of patterning the surface of the electrode comprises at least laser etching or etching. The process of ornamentation of the surface comprises at least masking. Masking is the operation by which at least a portion of the surface of the electrode is covered by a protective coating for post-treatment, e.g. chemical etching of the uncovered portions.

According to a third subject of the invention, the transparent substrate according to the present invention is incorporated in a photonic device emitting or collecting light. According to a preferred embodiment, the photonic device is an organic electroluminescent device comprising at least one transparent substrate according to the invention described above.

According to a variation of the preceding embodiment, the organic electroluminescent device comprises, above the substrate according to the invention, an OLED system designed to emit an almost white light. To produce almost white light, several methods are possible: by mixing, within a single organic layer of compounds emitting red, green and blue light, by stacking three organic layer structures respectively corresponding to the red light emitting parts, green and blue or two structures of organic layers (yellow and blue emission), by juxtaposition of three (emission red, green, blue) or two structures of organic layers (emission yellow and blue) associated with a system of diffusion of the light .

By the term almost white light is meant a light whose chromatic coordinates at 0 °, for radiation perpendicular to the surface of the substrate, are included in one of the eight quadrilaterals of chromaticity, including quadrilaterals. These quadrilaterals are defined on pages 10 to 12 of the standard

ANSI_NEMA_ANSLG C78.377-2008. These quadrilaterals are shown in Figure A1, entitled "Graphical representation of the chromaticity specification of SSL products in Table 1, on the CIE (x, y) chromaticity diagram".

According to a particular embodiment, the organic electroluminescent device is integrated in a glazing unit, a double glazing unit or a laminated glazing unit. It is also possible to integrate several electroluminescent organic devices, preferably a large number of organic electroluminescent devices.

According to another particular embodiment, the organic electroluminescent device is enclosed in at least one encapsulating material made of glass and / or plastic. The different embodiments of organic electroluminescent devices can be combined.

Finally, the various organic electroluminescent devices have a wide field of use. The invention is intended in particular for the possible uses of these organic electroluminescent devices for the producing one or more light surfaces. The term illuminated surface includes, for example, illuminating slabs, illuminated panels, light partitions, worktops, greenhouses, flashlights, wallpapers, drawer bottoms, illuminated roofs, touch screens, lamps, photo flashes, illuminated backgrounds. display, safety signs, shelves.

The transparent substrate according to the invention will now be illustrated with the aid of the following figures. The figures show in a nonlimiting manner a number of substrate structures, more particularly layer stack structures constituting the electrode included in the substrate according to the invention. These figures are purely illustrative and do not constitute a presentation at the scale of the structures. In addition, the performance of organic electroluminescent devices comprising the transparent substrate according to the invention will also be presented in the form of figures.

FIG. 1: Cross-section of a transparent substrate according to the invention, the substrate comprising an electrode constituted by a stack comprising a minimum number of layers.

Fig. 2: Cross section of a transparent substrate according to the invention, according to a second embodiment.

Fig. 3: Cross section of a transparent substrate according to the invention, the substrate comprising an electrode consisting of a stack having a minimum number of layers having a different effect.

Fig. 4: Cross section transparent substrate according to the invention, according to a preferred embodiment.

Fig. 5: Evolution of the luminance of an organic electroluminescent device emitting an almost white light and comprising a support having a refractive index at 1.4 at a wavelength equal to 550 nm depending on the geometric thickness of the coating for improving light transmission, having a refractive index of 2.3 at a wavelength of 550 nm, and the geometric thickness of a metal conduction layer in Ag.

Fig. 6: Evolution of the luminance of an organic electroluminescent device emitting an almost white light and comprising a support having a refractive index at 1.5 at a wavelength equal to 550 nm as a function of the geometric thickness of the coating. improvement of light transmission, having a refractive index of 2.3 at a wavelength of 550 nm, and the geometric thickness of a metal conduction layer in Ag.

Fig. 7: Evolution of the luminance of an organic electroluminescent device emitting an almost white light and comprising a support having a refractive index of 1.6 at a wavelength equal to 550 nm as a function of the geometric thickness of the coating of improvement of light transmission, having a refractive index of 2.3 at a wavelength of 550 nm, and the geometric thickness of a metal conduction layer in Ag.

Fig. 8: Evolution of the luminance of an organic electroluminescent device emitting an almost white light and comprising a support having a refractive index of 1.8 at a wavelength equal to 550 nm as a function of the geometric thickness of the coating; improvement of light transmission, having a refractive index of 2.3 at a wavelength of 550 nm, and the geometric thickness of a metal conduction layer in Ag.

Fig. 9: Evolution of the luminance of an organic electroluminescent device emitting an almost white light and comprising a support having a refractive index at 2.0 at a wavelength equal to 550 nm as a function of the geometric thickness of the coating. improvement of light transmission, having an index of refraction of 2.3 at a wavelength of 550 nm, and the geometric thickness of a conductive metal layer in Ag.

Fig. 10: Photoluminescence as a function of the wavelength spectrum of a monochromatic radiation whose main wavelength is in the field of red light.

Fig. 11: Photoluminescence as a function of the wavelength spectrum of a monochrome radiation whose main wavelength is in the green light domain.

Fig. 12: Photoluminescence as a function of the wavelength spectrum of a monochrome radiation whose main wavelength is in the field of blue light.

Fig. 13: Evolution of the luminance of the organic electroluminescent device according to the geometric thickness and the refractive index of the light transmission enhancement layer of the electrode according to the invention for a red light, a layer Ag conduction metal having a geometric thickness equal to 12.5 nm and a support having a refractive index of 1.5.

Fig. 14: Evolution of the luminance of the organic electroluminescent device as a function of the geometric thickness and the refractive index of the light transmission enhancement layer of the electrode according to the invention for a green light, a layer Ag conduction metal having a geometric thickness equal to 12.5 nm and a support having a refractive index of 1.5.

Fig. 15: Evolution of the luminance of the organic electroluminescent device as a function of the geometric thickness and the refractive index of the light transmission enhancement layer of the electrode according to the invention for a blue light, a layer Ag conduction metal having an equal geometric thickness at 12.5 nm and a support having a refractive index of 1.5.

Fig. 16: Evolution of the luminance of the organic electroluminescent device as a function of the geometrical thickness and the refractive index of the transmission enhancement layer of the electrode according to the invention for a red light, a metallic layer of Ag conduction having a geometric thickness equal to 12.5 nm and a support having a refractive index of 2.0.

Fig. 17: Evolution of the luminance of the organic electroluminescent device as a function of the geometric thickness and the refractive index of the light transmission enhancement layer of the electrode according to the invention for a green light, a layer Ag conduction metal having a geometric thickness equal to 12.5 nm and a support having a refractive index of 2.0.

Fig. 18: Evolution of the luminance of the organic electroluminescent device as a function of the geometric thickness and the refractive index of the light transmission enhancement layer of the electrode according to the invention for a blue light, a layer Ag conduction metal having a geometric thickness equal to 12.5 nm and a support having a refractive index of 2.0.

Fig. 19: Evolution of the simulated reflection expressed in D65 at 2 ° in accordance with the European standard EN 410, of a transparent substrate, comprising a support having a refractive index equal to 1.5 at a wavelength equal to 550 nm as a function of the geometric thickness of the light transmission enhancement coating and the geometrical thickness of the Ag metal conduction layer, the substrate also comprising a sacrificial layer above the conduction layer TiO _x having a geometrical thickness equal to 3.0 nm and a Zn _x Sn _y O _z insertion layer (with x + y ≥ 3 and z ≤ 6) having a geometric thickness equal to 14.7 nm, the insertion layer being coated with an organic medium of refractive index equal to 1.7 at a wavelength of 550 nm.

Fig. 20: Evolution of the luminance of the organic electroluminescent device incorporating a transparent substrate comprising a support having a refractive index of 1.5 at a wavelength of

550 nm and a metal conduction layer having a geometric thickness of 12.5 nm, depending on the geometrical thicknesses of the insertion layer (Ein) and the first organic layer of the electrode for a green light.

FIG. 1 represents an example of a stack constituting a transparent substrate according to the invention. The transparent substrate has the following structure from the support (10):

A light transmission enhancement (HO) coating comprising a light transmissive enhancement layer (1101)

• A conductive metal layer (112)

FIG. 2 represents an alternative example of a transparent substrate according to the invention. This comprises, in addition to the layers already present in FIG. 1, an insertion layer (113) and a uniformity layer of the surface electrical properties (114). The transparent substrate has the following structure from the support (10):

A light transmissive enhancement coating (110) comprising a light transmissive enhancement layer (1101)

• A conductive metal layer (112)

• An insertion layer (113)

• A standardization layer (114)

Figure 3 shows another transparent substrate according to the invention. This comprises, in addition to the layers already present in FIG. 2, an additional barrier layer (1100) and a layer additional crystallization device (1102) belonging to the light transmission enhancement coating (110), two sacrificial layers (111a, 111b) and a functional coating (9) on the second side of the carrier (10). The transparent substrate has the following structure from the second face of the support (10):

• Functional coating (9)

• Support (10)

• A light transmissive enhancement coating (110) comprising: o A barrier layer (1100) o A light transmission enhancement layer

(HOl) o A crystallization layer (1102)

• A sacrificial layer (111a) • A metallic conduction layer (112)

• A sacrificial layer (111b)

• An insertion layer (113)

• A standardization layer (114)

FIG. 4 represents another example of a transparent substrate according to the invention. The substrate has the following structure from the support (10):

A light transmissive enhancement coating (110) comprising a light transmissive enhancement layer (1101). A conductive metal layer (112).

• A sacrificial layer (111b)

• An insertion layer (113)

• A standardization layer (114)

FIGS. 5, 6, 7, 8 and 9 show the evolution of the luminance of an organic electroluminescent device emitting an almost white light as a function of the geometric thickness of the light transmission enhancement coating (D1) having a refractive index of 2.3 (n _D1 ) at a wavelength of 550 nm, and the geometric thickness of a metal conduction layer in Ag and comprising a support having respectively a refractive index equal to 1.4, 1.5, 1.6, 1.8 and 2.0 at a wavelength equal to 550 nm. The structure of the organic electroluminescent device comprises the following stack:

Support (10) having a geometrical thickness equal to 100.0 nm

• Electrode (11):

- Coating for improving light transmission

(HO),

metal conduction layer in Ag (112),

The organic part of the organic electroluminescent device is such that it has the following structure:

a hole transport or HTL layer for "HoIe Transporting Layer" in English having a geometrical thickness equal to 25.0 nm,

a layer blocking the electrons or EBL for

"Electron Blocking Layer" in English having a geometric thickness equal to 10.0 nm,

an emitting layer, emitting a Gaussian spectrum of white light corresponding to the illuminant A in the and having a geometric thickness equal to 16.0 nm,

a hole blocking layer or HBL for "HoIe Blocking Layer" in English having a geometric thickness equal to 10.0 nm,

an electron transport layer or ETL for "Electron Transporting Layer" in English having a geometric thickness equal to 43.0 nm. • An Al counter electrode with a thickness of 100.0 nm

Surprisingly, these calculations show that a maximum luminance is obtained for a transparent substrate such as the optical thickness of the coating having light transmission enhancement properties (110), T ₀₁ , and the geometrical thickness. of the conduction metal layer (112), T _ME , are connected by the relation:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{ol 0} )] / n ³ _support

where T _{ME 0} , B and T _{01 0} are constants with T _{ME 0} having a value in the range of 10.0 to 25.0 nm, B having a value in the range of 10.0 to 16 , 5 and T _{01 0} having a value in the range of 23.9 * n _D1 to 28.3 * n _D1 nm with n _D1 representing the refractive index of the coating for improving the transmission of light to a wavelength of 550 nm, n _support represents the refractive index of the support at a wavelength of 550 nm.

Luminance was calculated using the SETFOS version 3 program

(Semiconducting_Emissive Thin Film Optics Simulator) of the company Fluxim.

This luminance is expressed in arbitrary units. The sinusoids appearing in the form of thicker lines represent the extreme values of the domain selected by the equation T _ME = T _{ME 0} + [B * sin (IT * T ₀₁ /

T _{01 0} )] / ( ^π _support ) ³ - The inventors have determined that, surprisingly, the selected domain is not only valid for an organic device emitting almost white light but also for any type of color emitted (for example : red, green, blue).

The inventors have determined that with an equal transparent substrate structure, the use of a support (10) having a high refractive index makes it possible to increase the quantity of light transmitted by the photonic system. By high refractive index is meant a refractive index at least equal to 1.4, preferably at least 1.5, more preferably at least equal to 1.6, most preferably at least 1.7. Indeed, as shown in the comparison of FIGS. 5 and 9, there is an increase of about 180% in the luminance of the OLED device when, with a transparent substrate structure equal, a support having a refractive index equal to 2 is used. In place of a refractive index support equal to 1.4, the refractive index of the support being the refractive index at a wavelength of 550 nm.

FIGS. 10 to 19, more particularly FIGS. 13 to 19, relate to a particular example of a transparent substrate according to the invention, which corresponds to an Ag conduction layer having a geometric thickness equal to 12.5 nm. In these figures, the substrate according to the invention is incorporated in an OLED device emitting a red, green or blue color. The structure of the organic electroluminescent device comprises the following stack:

Support (10) having a geometrical thickness equal to 100.0 nm

• Electrode (11):

- Coating for improving light transmission

(HO),

metal conduction layer in Ag (112),

an electron blocking layer or EBL for "Electron Blocking Layer" in English having a geometric thickness equal to 10.0 nm,

an emitting layer, giving rise to an emission of a red, green or blue light spectrum whose chromatic coordinates are respectively equal to the coordinates (0.63, 0.36), (0.24, 0.68) or (0.13;

0.31) in the CIE XYZ 1931 color chart, depending on whether the device is designed to emit red, green or blue light and has a geometric thickness of 16.0 nm,

- a layer blocking the holes or HBL for "HoIe

Blocking Layer "in English having a geometric thickness equal to 10.0 nm,

an electron transport layer or ETL for "Electron Transporting Layer" in English having a geometric thickness equal to 43.0 nm.

• An Al counter electrode with a thickness of 100.0 nm

Figures 10, 11 and 12 respectively show the evolution of photoluminescence as a function of the wavelength spectra of a monochrome radiation whose main wavelength is in the field of red, green and blue light. By main length is meant the wavelength for which the photoluminescence is maximum. The term "monochrome" means that only one color is perceived by the eye without this light being monochromatic. Photoluminescence is expressed as the ratio of the value of photoluminescence at a wavelength divided by the value of maximum photoluminescence. Photoluminescence is therefore a unitless number between 0 and 1. These figures clearly show that the light emitted by the OLED device can not be simply limited to a single wave length. Figure 10 shows that at a wavelength of 616 nm, photoluminescence is maximum in the case of monochrome radiation whose main wavelength is in the field of red color. FIG. 11 shows that at a wavelength of 512 nm, photoluminescence is maximum in the case of monochrome radiation whose main wavelength is in the green color range. Figure 12 shows that at a wavelength of 453 nm, photoluminescence is maximum in the case of monochrome radiation whose main wavelength is in the field of blue color.

FIGS. 13, 14 and 15 show the evolution of the luminance of the organic electroluminescent device as a function of the geometric thickness (D1) and the refractive index of the light transmission enhancement coating (n _D1 ) ( 110) of the transparent substrate according to the invention for respectively a red, green and blue light, and for a support having a refractive index of 1.5 at a wavelength of 550 nm, the geometrical thickness of the Ag conduction layer being equal to 12.5 nm. This calculation was made taking into account not a light radiation limited to a single wavelength but taking into account the real wavelength spectrum as shown in Figures 10, 11 and 12. Surprisingly, these calculations show that a maximum luminance is obtained for a transparent substrate which is such that the optical thickness of the coating having light transmission enhancement properties (110), T ₀₁ , and the geometric thickness of the conductive metal layer (112), T _ME , are connected by the relation:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

where T _{ME 0} , B and T _{01 0} are constants with T _{ME 0} having a value in the range of 10.0 to 25.0 nm, B having a value in the range of 10.0 to 16 , 5 and T _{01 0} having a value in the range of 23.9 * n _D1 to 28.3 * n _D1 with n _D1 representing the refractive index of the coating for improving the transmission of light at a wavelength of 550 nm, n _support represents the refractive index of the support at a wavelength of 550 nm. The luminance was calculated using the SETFOS version 3 program (Semiconducting Emissive Thin Film Optics Simulator) of the company Fluxim. For the particular case described above, the transparent substrate comprising a support having a refractive index of 1.5 at a wavelength of 550 nm and an Ag conduction layer having a geometric thickness equal to 12.5 nm, it is observed on the basis of FIGS. 13, 14, 15, obtained for an OLED device emitting respectively a red, green and blue light, that a high luminance is more particularly obtained when the geometric thickness of the improvement coating of the light transmission is at least equal to 50.0 nm, preferably to the month equal to 60.0 nm, more preferably at least equal to 70.0 nm and at most equal to 110.0 nm, preferably at most equal to 100, 0 nm, more preferably at most equal to 90.0 nm, most preferably at most equal to 80.0 nm. Similarly, based on FIG. 6, describing the evolution of the luminance of an organic electroluminescent device emitting an almost white light and comprising a support having a refractive index at 1.5 at a wavelength equal to 550 nm as a function of the geometric thickness of the light transmission enhancement coating, having a refractive index of 2.3 at a wavelength of 550 nm, and the geometrical thickness of a metallic layer of Ag conduction, for a substrate having an Ag conduction metal thickness of 12.5 nm, it is observed that the optimum geometrical thickness of the light transmission enhancement coating should be between 50.0 nm and 130.0 nm.

FIGS. 16, 17 and 18 show the evolution of the luminance of the organic electroluminescent device as a function of the geometric thickness (D1) and the refractive index of the light transmission enhancement coating (n _D1 ) ( 110) of the transparent substrate according to the invention for respectively a light of red, green and blue color, and for a medium having a refractive index of 2.0 at a wavelength of 550 nm, the geometric thickness of the conduction layer at Ag being 12.5 nm. This calculation was made taking into account not a light radiation limited to a single wavelength but taking into account the real wavelength spectrum as shown in Figures 10, 11 and 12. Surprisingly, these calculations also show that a maximum luminance is obtained for a transparent substrate which is such that the optical thickness of the coating provided with light transmission enhancement properties (110), T ₀₁ , and the geometric thickness of the conductive metal layer (112), T _ME , are connected by the relation:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

where T _{ME 0} , B and T _{01 0} are constants with T _{ME 0} having a value in the range of 10.0 to 25.0 nm, B having a value in the range of 10.0 to 16 , 5 and T _{01 0} having a value in the range of 23.9 * n _D1 to 28.3 * n _D1 with n _D1 representing the refractive index of the coating for improving the transmission of light at a wavelength 550 nm, n _support represents the refractive index of the support at a wavelength of 550 nm. The luminance was calculated using the SETFOS version 3 program (Semiconducting Emissive Thin Film Optics Simulator) of the company Fluxim. For the particular case described above, it is observed on the basis of FIGS. 16, 17, 18, obtained for an OLED device emitting respectively a red, green and blue light, that a high luminance is more particularly obtained when the geometrical thickness the coating for improving light transmission is at least 40.0 nm, preferably at least 50.0 nm, more preferably at least 60.0 nm and at most equal to 110.0 nm, preferably at most equal to 100.0 nm, more preferably at most equal to 90.0 nm. Similarly, based on FIG. 9 describing the evolution of the luminance of an organic electroluminescent device emitting an almost white light and comprising a support having a refractive index of 2.0 at a wavelength of 550 nm depending on the geometric thickness of the light transmissive coating having a refractive index of 2.3 at a wavelength of 550 nm, and the geometric thickness of a metal conduction layer in Ag, it is observed, for a substrate having a conduction metal thickness of 12.5 nm Ag, that The optimum geometric thickness of the light transmission enhancement coating should be at least greater than 3.0 nm and at most 200.0 nm.

All of FIGS. 13 to 18 show that, for a substrate structure equal to a refractive index of the fixed support, a higher luminance is obtained when the refractive index of the coating for improving the transmission of light (110 ) is larger than the refractive index of the support (10), particularly when n _D1 > 1.2 n _support , more particularly n _D1 > 1.3 n _support , most particularly n _D1 > 1.5 n _support . The refractive index of the material constituting the coating (n _D1 ) has a value ranging from 1.5 to 2.4, preferably ranging from 2.0 to 2.4, more preferably ranging from 2.1 to 2.4 to a wavelength of 550 nm.

Surprisingly, the inventors have determined that the optimum thickness of the improvement coating to obtain a maximum luminance, in other words a high emission level, depends little on the wavelength spectrum of the monochrome radiation. (Blue, green or red light) as shown in Figures 13 to 18. More surprisingly, this optimum is in the same range of geometric thickness improvement coating (110). For example, for a material having a refractive index ranging from 2.0 to 2.3, the geometric thickness of the improvement coating allowing optimum emission at different wavelengths has a value ranging from 45.0 to 95 0 nm. This interval is centered on a geometric thickness value of 70.0 nm. Furthermore, the respective comparisons of Figures 8 and 11 for red light, Figures 9 and 12 for green light and Figures 10 and 13 for light blue show that the refractive index of the support has a small influence on the optimum thickness range of the improvement coating.

The inventors have determined that in addition to providing a high level of emission, the use of a transparent substrate such as the optical thickness of the coating with light transmission enhancement properties (110), T ₀₁ , and the geometrical thickness of the conductive metal layer (112), T _ME , are connected by the relation:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

allows to provide near-white light when red, blue and green light sources are used concomitantly as shown in FIGS. 5 to 9. More particularly, as shown in FIGS. 13 to 15, when the transparent substrate is such that it consists of a support having a refractive index equal to 1.5 at a wavelength of 550 nm and having an Ag conduction layer having a geometric thickness equal to 12.5 nm, the inventors were able to surprisingly determined for any material whose refractive index is within a range of values from 2.0 to 2.3, the optimum geometrical thickness of the improvement coating (110) has a value of 45 at 95 nm makes it possible to obtain an almost white light. The almost white light is preferably obtained for a geometric thickness ranging from 60.0 to 80.0 nm, more preferably from 65.0 to 75.0 nm. Thus, the concomitant use of three light sources emitting colorimetric coordinate spectra (0.63, 0.36) for the red light source, (0.26, 0.68) for the green light source and ( 0.13, 0.31) for the blue light source provides near-white light for light transmissive enhancement coating having a geometric thickness of 70.0 nm and a refractive index of 2.3.

On the basis of FIGS. 5 to 7, the inventors have determined that, surprisingly, two particular domains could be selected in transparent substrate structures for incorporation into an organic electroluminescent device.

The first area of selection relates to transparent substrates such as the support at a refractive index equal to 1.5 at a wavelength of 550 nm and that the geometrical thickness of the metal conduction layer is at least equal to 6, 0 nm, preferably at least 8.0 nm, more preferably at least 10.0 nm and at most equal to 22.0 nm, preferably at most 20.0 nm, more preferably at most 18 , 0 nm and whose geometric thickness of the coating for improving the transmission of light is at least equal to 50.0 nm, preferably to the month equal to 60.0 nm and at most equal to 130.0 nm, preferably to more equal to 110.0 nm, more preferably at most equal to 90.0 nm. This structure has the triple advantage of using a low cost silicosodocalcic glass support, to use finer conduction layers (eg Ag) combined with coating thicknesses to improve light transmission more. such thicknesses are used to obtain better protection of the metal conduction layer against possible pollution by migration of alkali from the silica-lime glass support.

The second area of selection relates to transparent substrates such that it comprises a support having a refractive index value in the range of 1.4 to 1.6 and is such that the geometrical thickness of the metal layer of conduction is at least equal to 16 nm, preferably at least 18 nm, more preferably at least 20 nm and at most equal to 29 nm, preferably at most 27 nm, more preferably at most 25 nm and of which the geometric thickness of the light transmission enhancement coating is at least 20.0 nm and at most 40.0 nm. This structure has the advantage of using thicker conductive metal layers (for example in silver), the use of a thick conductive metal layer making it possible to obtain better conduction. FIG. 19 represents the evolution of the simulated reflection expressed in D65 at 2 ° in accordance with the European standard EN 410, of a transparent substrate, comprising a support having a refractive index equal to 1.5 at a wavelength equal to 550 nm, depending on the geometric thickness of the coating for improving light transmission and the geometrical thickness of the Ag metal conduction layer, the substrate also comprising above the conduction layer a TiO _x sacrificial layer having a geometrical thickness equal to 3.0 nm and a Zn _x Sn _y O _z insertion layer (with x + y ≥ 3 and z ≤ 6) having a geometric thickness equal to 14, 7 nm, the insertion layer being coated with an organic medium of refractive index equal to 1.7 at a wavelength of 550 nm. Sinusoids appearing in the form of thicker lines mark the extreme values of the domain selected by the equation T _ME = T _{ME 0} + [B * sin (LT * T ₀₁ / T _{D1 0} )] / (n _support ) ³ . The inventors have determined that, surprisingly, the selected domain does not correspond to the domain having the minimum reflection but corresponds to a reflection at least equal to 28% and at most equal to 49%, the reflection being calculated according to the standard EN 410.

FIG. 20 represents the evolution of the luminance of the organic electroluminescent device incorporating a transparent substrate comprising a support having a refractive index of 1.5 at a wavelength of 550 nm and a metal conduction layer having a geometrical thickness of 12.5 nm, depending on the geometrical thicknesses of the insertion layer

(113) (Ein) and the first organic layer of the electrode (Eorg) for a green light. This calculation was made taking into account not a light radiation limited to a single wavelength but taking into account the real wavelength spectrum as shown in FIG. 11. The luminance was also calculated in FIG. using the SETFOS version program

3. This luminance is expressed in arbitrary units. The inventors have determined that, surprisingly, two domains characterized by luminance maxima are observed: The first domain corresponding to the relationship: E _org = E _1n -A or A is a constant whose value lies in the range from 5.0 to 75.0 nm, preferably from 20.0 to 60.0 nm more preferably 30.0 to 45.0 nm.

The second domain corresponding to the relation: E _org = E _1n -C or C is a constant whose value is in the range from 150.0 to 250.0 nm, preferably from 160.0 to 225.0 nm more preferably from 75.0 to 205.0 nm.

The inventors have determined that the relations E _org = E _{1n -A} or E _org = E _1n -C make it possible to use the geometrical thickness of the first organic layer of the organic electroluminescent device to optimize the optical parameters (geometrical thickness and refraction) of the insertion layer and thus optimize the amount of light transmitted while keeping a thickness of the insertion layer compatible with electrical properties to avoid high ignition voltages and for respectively a first maximum of luminance and a second maximum of luminance.

The transparent substrate according to the invention, its embodiment as well as the organic electroluminescent device comprising it, will now be characterized, using the examples of embodiments described and shown in Table Ib and Hb below. These examples are in no way limitative of the invention.

The electroluminescent organic devices emitting monochromatic green radiation whose performance is shown in Tables Ia to VI comprise the following organic structure from the substrate (1):

A layer of N, N'-bis (1-naphthyl) -N, N'-diphenyl-1,1'-biphenyl-4,4'-diamine, abbreviated alpha-NPD,

A layer of 1,47-triazacyclononane-N, N ', N "-triacetate (abbreviated as TCTA) + Tris [2- (2-pyridinyl) phenyl-C, N] -iridium, abbreviated as Ir (ppy ) ₃ , A layer of 4,7-diphenyl-l, 10-phenanthroline (abbreviated BPhen),

• a layer of LiF,

A reflective upper electrode comprising at least one metal. According to a preferred embodiment, the metal of the reflective upper electrode comprises at least Ag. According to an alternative embodiment, the metal of the reflective upper electrode comprises at least Al.

The electroluminescent organic devices emitting an almost white light whose performance is shown in Table VII comprise, in addition to the transparent substrate according to the invention, the following structure from the substrate:

A layer of N, N, N ', N "-tetrakis (4-methoxyphenyl) benzidine (abbreviated MeO-TPD) doped with 4% by mole of NPD-2

A layer of N, N'-di (naphthalen-1-yl) -N-N'-diphenyl-benzidine (abbreviated to NPB)

A stack of emitting layers consisting of 4,4 ', 4 "-tris (N-carbazolyl) -triphenylamine (abbreviated TCTA) and 2,2', 2" (1,3,5-benzenetriyl) tris- ( 1-phenyl-1H-benzimidazole) (abbreviated TBPi) partially doped with iridium-bis- (4,6-difluorophenyl-pyridinato-N, C2) -picolinate (abbreviated FirPic), Tris [2- ( 2-pyridinyl) phenyl-C, N] iridium (abbreviated as Ir (ppy) 3) and iridium (III) bis (2-methyldibenzo [f, h] quinoxaline) (acetylacetonate) (abbreviated Ir5MDQ) ₂ ( acac)

A layer of 2,2 ', 2 "(1,3,5-benzenetriyl) tris- (1-phenyl-1H-benzimidazole) (abbreviated as TBPi)

• a layer of 4,7-Diphenyl-l, 10-phenanthroline doped with Cs

Acronyms used to denote the compounds used are well known to those skilled in the art. The structure of the organic layers used is described on page 237 in the "Methods summary" section of the article by Reineke et al. in Nature, 2009, vol. 459, pp 234-238. The layers constituting the electrode (11) of the examples of transparent substrate (1) according to the invention were deposited by magnetron cathode sputtering on a clear glass support (10) having a thickness of 1.60 mm

The deposit conditions for each of the layers are as follows:

The TiO ₂ -based layers are deposited using a titanium target, at a pressure of 0.5 Pa in an Ar / O ₂ atmosphere,

The Zn _x Sn _y O _z- based layers are deposited using a ZnSn alloy target at a pressure of 0.5 Pa in an atmosphere

Ar / O ₂ ,

The Ag-based layers are deposited using an Ag target under a pressure of 0.5 Pa in an Ar atmosphere,

The Ti-based layers are deposited using a Ti target at a pressure of 0.5 Pa in an Ar atmosphere and may be partially oxidized by the following Ar / O ₂ plasma,

The standardization layers of Ti nitride-based electrical surface properties are deposited using a Ti target at a pressure of 0.5 Pa in an Ar / N ₂ 80/20 atmosphere. Examples:

Table Ia shows three columns with examples of transparent substrates (1) comprising different types of electrodes (number of layers, chemical nature and thickness of the layers) as well as the results of measurements of the electrical and optical performances obtained using the organic electroluminescent device incorporating these substrates. The general structure of the electroluminescent device has been described above (pp. 48, 1. 23 to 49, 1.7). Examples 1 R, 2 R and 3 R are three examples not in accordance with the invention. Example 1 R is a transparent substrate comprising an ITO electrode. Example 2 R is a transparent substrate comprising an electrode based on a stack of architectural low emissive type comprising an Ag conduction layer. Example 2R is a transparent substrate that is not optimized for an OLED because the electrode does not include uniformity layer (114) and the thickness of the improvement coating (110) has not been optimized and is therefore outside the optical thickness range respecting the relation:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

Example 3 R is a transparent substrate comprising an electrode based on a stack of architectural low emissive type comprising an Ag conduction layer. Example 3 R is a transparent substrate comprising a non-optimized electrode for an OLED comprising a uniformization layer (114) and whose thickness of the improvement coating (110) has not been optimized and is therefore in outside the optical thickness range of optical thickness respecting the relationship:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

In Examples 2 R and 3 R, the improvement coating (114) comprises a barrier layer (1100) which is merged with a light transmission enhancement layer (1101), which layer is covered by a layer of crystallization (1102). In addition, the crystallization (1102) and insertion (113) layers are of the same nature. These layers are Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6), Zn _x Sn _y O _z comprising not more than 95% by weight of zinc, the percentage by weight of zinc is expressed relative to to the total weight of the metals present in the layer.

Table Ib shows two columns with examples of transparent substrates comprising different types of electrodes (number of layers, chemical nature and thickness of the layers) as well as the results of measurements of the electrical and optical performances obtained using the organic electroluminescent device. incorporating these substrates. The general structure of the electroluminescent device has been described above (pp. 48, 1. 23 at 49, 1.7). Examples 4 and 5 illustrate substrates according to the invention as well as the electrical and optical performances of the device electroluminescent incorporating them. In these examples, the improvement coating (110) comprises a barrier layer (1100) which is merged with an improvement layer (1101), this layer is covered by a crystallization layer (1102). In addition, the crystallization (1102) and insertion (113) layers are of the same nature. These layers are Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6), Zn _x Sn _y O _z comprising not more than 95% by weight of zinc, the percentage by weight of zinc is expressed relative to to the total weight of the metals present in the layer.

The comparison of Tables Ia and Ib clearly shows the advantages offered by the transparent substrate according to the invention in terms of electrical and optical performance illustrated by Examples 4 and 5 of Table Ib. Indeed, in terms of electrical performance, with respect to the substrate comprising an ITO electrode, Example 1 R Table Ia, it is observed that an equivalent current flow is obtained by applying a reduced voltage of at least 9%. With respect to a transparent substrate comprising as electrode a conventional low emissive coating, Example 2 R Table Ia, an equivalent current flow is obtained by applying a reduced voltage of at least 37%. In terms of optical performance, with respect to the substrate comprising an ITO electrode, Example 1 R Table Ia, it is observed that an equivalent luminous flux is obtained by applying voltages at least 4% lower than the voltages applied to the ITO electrode. . Similarly with respect to a substrate comprising as an electrode a conventional low emissive coating, Example 2 R Table Ia, an equivalent luminous flux is obtained by applying voltages reduced to a minimum of 37%. With respect to a substrate comprising a non-optimized electrode for an OLED comprising a uniformization layer (114) and whose thickness of the enhancement coating (110) has not been optimized, example 3 R of Table IA, a Equivalent luminous flux is obtained by applying reduced voltages to a minimum of 17%.

Table Ia:

The support (10) is a clear glass with a geometric thickness equal to 1.60 mm.

The electrical performances are measured by the applied voltages (V) to obtain either a current of 10 mA / cm ² or a current of 100 mA / cm ² . The optical performances are measured by the applied voltages (V) to obtain either a luminous intensity of 1000 cd / m ² or 10000 cd / m ² .

Table Ib

The support (10) is a clear glass with a geometric thickness equal to 1.60 mm.

The electrical performances are measured by the applied voltages (V) to obtain either a current of 10 mA / cm ² or a current of 100 mA / cm ² . The optical performances are measured by the applied voltages (V) to obtain either a luminous intensity of 1000 cd / m ² or

10000 cd / m ² .

Table IIa shows three columns with examples of transparent substrate comprising different types of electrodes (number of layers, chemical nature and thickness of layers) and the results of calculation of maximum luminance expressed in arbitrary unit (ua) carried out using of SETFOS version 3 program of the company Fluxim for a monochrome radiation of red, green and blue light according to Figures 10, 11 and 12, respectively, for an organic electroluminescent device incorporating these substrates. The general structure of the electroluminescent device has been described above (pp. 39, 11, 11, 40, 17). Examples 1 R, 2 R, 3 R and 4 R are four examples not in accordance with the invention. Example 1 R is a transparent substrate comprising an ITO electrode, Example 2 R is a transparent substrate comprising an ITO electrode comprising a Fabry-Perot microcavity based on dielectric materials. Example 3 R is a transparent substrate comprising an electrode based on a low type stack architectural emissive comprising an Ag conduction layer (112), not comprising a uniformity layer of the surface electrical properties (114) and whose thickness of the improvement coating (10) has not been optimized . Example 4 R is a transparent substrate comprising an electrode based on a low architectural emissive type stack comprising an Ag conduction layer (112), also comprising a uniformity layer of surface electrical properties (114). ) and whose thickness of the improvement coating (110) has not been optimized. In Examples 3 R and 4 R, the enhancement coating (110) comprises a barrier layer (1100) which is merged with an enhancement layer (1101), which layer is covered by a crystallization layer (1102). In addition, the crystallization (1102) and insertion (113) layers are of the same nature. These layers are Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6), Zn _x Sn _y O _z comprising not more than 95% by weight of zinc, the percentage by weight of zinc is expressed relative to to the total weight of the metals present in the layer.

Table Hb shows a column with an example of a transparent substrate according to the invention (example 5) and the results of calculation of maximum luminance expressed in arbitrary unit (ua) carried out using the SETFOS version 3 program of the company Fluxim for a monochrome radiation of red, green and blue light according to FIGS. 10, 11 and 12, respectively, for an organic electroluminescent device incorporating this substrate. The general structure of the electroluminescent device has been described above (pp. 39, 11, 11, 40, 17). In this example, the improvement coating (110) has an optical thickness respecting the relationship:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

it comprises a barrier layer (1100) which is merged with an improvement layer (1101), this layer is covered by a crystallization layer (1102). In addition, the crystallization layers (1102) and insertion devices (114) are of the same nature. These layers are Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6), Zn _x Sn _y O _z comprising not more than 95% by weight of zinc, the percentage by weight of zinc is expressed relative to to the total weight of the metals present in the layer.

The comparison between the luminance values obtained for Example 5, Table Hb, of a transparent substrate according to the invention is clearly greater than the values obtained for Examples IR, 2R, 3R and 4R, Table 11a. This comparison clearly highlights the advantages offered by the substrate according to the invention. In fact, compared to the comparative example presenting the best performances (example 3 R, table HA), example 5 of the table Hb which uses a transparent substrate according to the invention makes it possible to obtain a maximum luminance increase. of the order of 47% in green light, of the order of 44% in red light and of the order of 33% in blue light.

Table lia:

The support (10) is a transparent glass with a geometrical thickness equal to 100 nm.

Hb Table:

Table III shows four columns with examples of electrodes (number of layers, chemical nature and layer thickness) and the results of calculation of maximum luminance expressed in arbitrary units (ua) carried out using the SETFOS version 3 program. the company Fluxim for monochrome radiation of red, green and blue light according to FIGS. 10, 11 and 12, respectively, for an organic electroluminescent device incorporating these substrates. The general structure of the electroluminescent device has been described above (pp. 39, 11, 11, 40, 17). Examples 1 R and 2 R are two examples of substrates not in accordance with the invention respectively comprising a glass of refractive index whose value is equal to 1.5 and a glass of refractive index equal to 2, 0 to a length of 550 nm. Examples 1 R and 2 R are transparent substrates comprising electrodes based on a low architectural emissive type stack comprising an Ag conduction layer (112), comprising a uniformity layer of the surface electrical properties ( 114) and whose thickness of the improvement coating (110) has not been optimized. In these examples, the improvement coating (110) comprises a barrier layer (1100) which is merged with an improvement layer (1101), this layer is covered by a crystallization layer (1102). In addition, the crystallization (1102) and insertion (11 3) layers are of the same nature. These layers are Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6), Zn _x Sn _y O _z comprising not more than 95% by weight of zinc, the percentage by weight of zinc is expressed relative to to the total weight of the metals present in the layer. Examples 3 and 4 illustrate transparent substrates according to the invention comprising respectively a glass of refractive index whose value is equal to 1.5 and a glass of refractive index equal to 2 to a length of wave of 550 nm. In these examples, the improvement coating (110) has an optical thickness respecting the relationship:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

it comprises a barrier layer (1100) which is merged with an improvement layer (1101), this layer is covered by a crystallization layer (1102). In addition, the crystallization (1102) and insertion (113) layers are of the same nature. These layers are in Zn _x Sn _y O _z (with x

+ y ≥ 3 and z ≤ 6), Zn _x Sn _y O _z comprising at most 95% by weight of zinc, the weight percentage of zinc is expressed relative to the total weight of the metals present in the layer.

The comparison of the different columns of Table III also clearly demonstrates the advantages offered by the transparent substrate according to the invention. Indeed, according to the color emitted by the light source, it is observed that an increase of at least 11% of the luminance can be obtained in the case of the use of high-index glass (Example 2 R and example 4 in blue light, glass of index 2.0) and at least 36% of the luminance can be obtained in the case of the use of glass of lower index (example 1 R and example 3 in blue light , glass of index 1.5). In other words, there is an increase in luminance regardless of the refractive index of the support used.

Table III

As described above, the transparent substrate according to the invention comprises a light transmission enhancement coating (110) comprising at least one additional crystallization layer. This layer allows a preferential growth of the metal layer, by example of silver, constituting the conduction layer and thereby to obtain good electrical and optical properties of the conduction layer. It comprises at least one inorganic chemical compound. The inorganic chemical compound constituting the crystallization layer does not necessarily have a high refractive index. The inorganic chemical compound comprises at least ZnO _x (with x ≤ 1) and / or Zn _x Sn _y O _z (with x + y> 3 and z ≤ 6). Preferably, the Zn _x Sn _y O _z comprises at most 95% by weight of zinc, the weight percentage of zinc is expressed relative to the total weight of the metals present in the layer. Surprisingly, the inventors have determined that the thickness of the crystallization layer must be adapted and increased to provide a metal conduction layer having good conduction and very little absorption. Indeed, the layer having the property of improving the transmission of light (1101) has a greater thickness than that usually encountered in the field of conductive multilayer coatings (for example: low emissive type coating). In a low emissivity type coating, the geometrical thickness of the layer between the support (10) and the crystallization layer (1102) is at most 30.0 nm, generally of the order of 20.0 nm, the geometric thickness of the crystallization layer being of the order of 5.0 nm. The inventors have determined that a geometric thickness of this type is sufficient to obtain a conduction layer having good conduction and making it possible to obtain a transparent electrode according to the invention having a resistance per square of less than 5 Ω / D. The inventors have however determined that the geometric thickness of the crystallization layer should preferably be at least 7 nm, more preferably at least 10 nm to obtain a resistance expressed in Ω / D lower. The geometrical thickness of the crystallization layer (1102) must therefore be at least equal to 7% of the sum of the thicknesses of the barrier layer (1100) and the light transmission enhancement layer (1102), preferably at 11%, more preferably at 14%. On the other hand, the optical thickness of the improvement coating (110) being in the optical thickness range respecting the relationship:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

The sum of the optical thicknesses of the layer with light transmission enhancement properties (1101) and the barrier layer (1100) should be reduced if the optical thickness of the crystallization layer (1102) is increased.

Table IV shows three columns with examples of transparent substrates comprising different types of electrodes (number of layers, chemical nature and layer thickness) and resistance measurement results expressed in Ω / h. The general structure of the electroluminescent device has been described above (pp. 48, 1. 23 at 49, 1.7). Example 1 R is a transparent substrate not according to the invention comprising an electrodes based on an architectural low-emission type stack comprising an Ag conduction layer (112), comprising a uniformity layer of the properties surface electrodes (114) and whose thickness of the improvement coating (110) has not been optimized. In these examples, the improvement coating (110) comprises a barrier layer (1100) which is merged with an improvement layer (1101), this layer is covered by a crystallization layer (1102). In addition, the crystallization (1102) and insertion (113) layers are of the same nature. These layers are Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6), Zn _x Sn _y O _z comprising not more than 95% by weight of zinc, the percentage by weight of zinc is expressed relative to to the total weight of the metals present in the layer. Examples 2 and 3 illustrate transparent substrates according to the invention. In these examples, the improvement coating (110) has an optical thickness respecting the relationship:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

it comprises a barrier layer (1100) which is merged with an improvement layer (1101), this layer is covered by a layer of crystallization (1102). In addition, the crystallization (1102) and insertion (113) layers are of the same nature. These layers are Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6), Zn _x Sn _y O _z comprising not more than 95% by weight of zinc, the percentage by weight of zinc is expressed relative to to the total weight of the metals present in the layer. Example 3 illustrates a transparent substrate according to the invention comprising an electrode optimized from the point of view of the geometric thickness of the crystallization layer (1102).

Table IV:

The support (10) is a clear glass with a geometric thickness equal to 1.60 mm.

As described above, the transparent substrate according to the invention comprises an electrode comprising at least one additional insertion layer (113). This insertion layer (113) has the function of constituting a portion of the optical cavity making the conduction layer transparent. Indeed, it is known to one skilled in the art who optimizes multilayer coatings of low emissive type, for example, that the use of an insertion layer having a geometric thickness of at least 15.0 nm is necessary. to make the conduction layer transparent. In However, no conductivity condition is imposed to obtain optical transparencies compatible with architectural applications. Layers developed for architectural applications can not be used directly for optoelectronic applications since they generally include dielectric compounds and / or low-conductive compounds.

The inventors have determined that, surprisingly, the geometric thickness of the insertion layer (E _1n ) (113) is such that, on the one hand, its ohmic thickness is at most equal to 10 ¹² Ohm, preferably at most equal at 10 ⁴ Ohm, the ohmic thickness being equal to the ratio between the resistivity of the material constituting the insertion layer (p) and the geometrical thickness of this same layer (1), and on the other hand the geometrical thickness of the insertion layer (113) is connected to the geometrical thickness of the first organic layer of the organic electroluminescent device (E _org ), the terms first organic layer denoting all of the organic layers between the insertion layer (113) and the organic electroluminescent layer. The inventors have thus determined, as indicated in FIG. 20, that, surprisingly, two domains characterized by luminance maxima are observed:

The first domain corresponding to the relationship: E _org = E _1n -A or A is a constant whose value lies in the range from 5.0 to 5.0 nm, preferably from 20.0 to 60.0 nm, more preferably from 30.0 to 45.0 nm.

The second domain corresponding to the relation: E _org = E _1n -C or C is a constant whose value is in the range from

150.0 to 250.0 nm, preferably 160.0 to 225.0 nm, more preferably 75.0 to 205.0 nm.

The inventors have therefore determined that the relations E _org = E _{1n -A} or E _org = E _1n -C make it possible to use the geometrical thickness of the first layer organic organic electroluminescent device to optimize the optical parameters (geometric thickness and refractive index) of the insertion layer and thus optimize the amount of light transmitted while keeping a thickness of the insertion layer compatible with electrical properties allowing to avoid high ignition voltages for a first luminance maximum and a second luminance maximum, respectively.

Moreover, the use of a dielectric or even a weakly conductive layer to make contact between the conduction layer and the organic part of the organic electroluminescent device runs counter to the thinking commonly accepted by the person skilled in the art to manufacture organic devices. EL. The inventors have determined that, surprisingly, the use of a dielectric material or even a weak conductor for producing the insertion layer (113) must not be excluded. However, a conductive material is preferred. Indeed, if the insertion layer has a too high ohmic thickness, the operating voltages increase considerably as shown in Table V.

Table V shows two columns with examples of transparent substrates comprising different types of electrodes (number of layers, chemical nature and thickness of the layers) as well as the results of measurements of the electrical and optical performances obtained using the organic electroluminescent device. incorporating these transparent substrates.

The general structure of the electroluminescent device has been described above (pp. 48, 1. 23 at 49, 1.7). Example 1 R is a transparent substrate comprising an electrode based on a stack of architectural low emissive type comprising a conduction layer (112) with Ag. Example 1 R is therefore a transparent substrate which does not conform to the invention since it comprises a non-optimized electrode for an OLED. The electrode of the IR substrate comprises a uniformization layer (114) and a light transmission enhancement coating (110) whose optical thickness has has not been optimized and is therefore outside the thickness range respecting the relationship:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

In the IR example, the enhancement coating (110) comprises a barrier layer (1100) which is merged with an enhancement layer (1101), which layer is covered by a crystallization layer (1102). In addition, the crystallization (1102) and insertion (113) layers are of the same nature. These layers are Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6), Zn _x Sn _y O _z comprising not more than 95% by weight of zinc, the percentage by weight of zinc is expressed relative to to the total weight of the metals present in the layer. In addition, Example 1 R also has an insertion layer (113) whose geometrical thickness has not been optimized. Example 2 illustrates an electrode according to the invention. In this example, the improvement coating (2) has an optical thickness respecting the relationship:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

it comprises a barrier layer (1100) which is merged with an improvement layer (1101), this layer is covered by a crystallization layer (1102). In addition, the crystallization (1102) and insertion (110) layers are of the same nature. These layers are Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6), Zn _x Sn _y O _z comprising not more than 95% by weight of zinc, the percentage by weight of zinc is expressed relative to to the total weight of the metals present in the layer. It is observed that the electrical properties of Example 2 are significantly improved over those presented in Example IR which is a comparative example.

Table V:

The support (10) is a clear glass with a geometric thickness equal to 1.60 mm.

Finally, Table VI shows that at constant geometric thickness of the insertion layer, it is possible to lower the operating voltages by decreasing the resistivity of this layer. Indeed, Table VI shows three columns with examples of transparent substrates according to the invention but differing from each other by the nature of the chemical compound constituting the insertion layer and the results of performance measurements. electrical and optical obtained using the organic electroluminescent device incorporating these electrodes. The general structure of the electroluminescent device has been described above (pp. 48, 1. 23 at 49, 1.7). Example 1 illustrates a transparent substrate according to the invention comprising an electrode whose insertion layer comprises an aluminum doped zinc oxide conductive layer (ZnO resistivity: A1: 10 ^'4 Ω * cm). Example 2 illustrates a transparent substrate according to the invention comprising an electrode whose insertion layer comprises a Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6) low-conducting layer, the Zn _x Sn _y O _z comprising at most 95% by weight of zinc, the weight percentage of zinc is expressed relative to the total weight of the metals present in the layer (resistivity of Zn _x Sn _y O _z : 10 ² Ω * cm) . Example 3 illustrates a transparent substrate according to the invention comprising an electrode whose layer insertion includes a dielectric layer of titanium dioxide (TiO ₂ resistivity: 70 10 Ω · cm ^4).

It is observed that to reach a current level of 100 mA, the voltage to be applied is lower with a conductive insertion layer comprising a layer made of a conductive material with a layer made of a dielectric material.

Table VI

The support (10) is a clear glass with a geometric thickness equal to 1.60 mm. Table VII shows organic electroluminescent devices emitting an almost white light. The general structure of the electroluminescent device has been described above (page 49, 1. 8 to 31). Example 1 R is a transparent substrate comprising an electrode based on a stack of architectural low emissive type comprising a conduction layer with Ag. Example 1 R is a transparent substrate comprising a non-optimized electrode for an OLED comprising a uniformization layer (114) and whose thickness of the improvement coating (110) has not been optimized and is therefore in outside the optical thickness range of optical thickness respecting the relationship: T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

In Example 1 R, the improvement coating (114) comprises a barrier layer (1100) which is merged with a light transmission enhancement layer (1101), this layer is covered by a crystallization layer ( 1102). In addition, the crystallization (1102) and insertion (113) layers are of the same nature. These layers are Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6), Zn _x Sn _y O _z comprising not more than 95% by weight of zinc, the percentage by weight of zinc is expressed relative to to the total weight of the metals present in the layer. Examples 2 and 3 represent examples according to the invention. In these examples, the improvement coating (110) has an optical thickness respecting the relationship:

T _ME = T _ME _o + [B * sin (π * T ₀₁ / T _{D1 0} )] / (n _support ) ³

it comprises a barrier layer (1100) which is merged with an improvement layer (1101), this layer is covered by a crystallization layer (1102). In addition, the crystallization (1102) and insertion (114) layers are of the same nature. These layers are Zn _x Sn _y O _z (with x + y ≥ 3 and z ≤ 6), Zn _x Sn _y O _z comprising not more than 95% by weight of zinc, the percentage by weight of zinc is expressed relative to to the total weight of the metals present in the layer. Example 2 illustrates more particularly a transparent substrate comprising a thin metal layer and having a coating thickness for improving the higher light transmitting properties. The advantage of such an improvement coating thickness is that it allows:

on the one hand, to obtain better protection of the metal conduction layer against possible pollution of said layer by migration of pollutants from the substrate, in this case a migration of alkalis from the glass substrate,

- on the other hand, to use less precious metal for the realization of the metal conduction layer.

Example 3 illustrates a transparent substrate comprising a thick silver layer for obtaining a conduction layer having a low resistance.

The comparison of the properties obtained for devices emitting quasi-white light incorporating a transparent substrate according to Examples IR, 2 and 3 demonstrates that

the life times of the devices comprising a substrate according to the invention are longer compared with the IR example but also with respect to a transparent substrate consisting of an identical support (10) and surmounted by an ITO electrode having a thickness geometric equal to 90 nm whose life time is 162 hours (result not shown in Table VII);

the surface resistance (Ω / h) of Example 3 having a thick conduction layer is at least two times lower than the surface resistance (Ω / h) of Examples 2 and IR, this property offers the possibility of making devices larger dimension without the use of conduction reinforcement such as for example a metal grid;

the optical performances obtained with organic electroluminescent devices comprising examples of transparent substrates according to the invention (Examples 2 and 3) are greater than those obtained with the comparative example IR. Indeed, the voltage applied to obtain the same light intensity is lower in Examples 2 and 3 compared to the IR example.

Table VII

The support (10) is a clear glass with a geometric thickness equal to 1.60 mm.

The electrical performances are measured by the applied voltages (V) to obtain a current of 2 mA / cm ² . The optical performances are measured by the applied voltages (V) to obtain either a luminous intensity of 1000 cd / m ² or 10000 cd / m ² .

Claims

A transparent substrate (1) for photonic devices comprising a support (10) and an electrode (11), said electrode (11) comprising a stack comprising a single conduction metal layer (112) and at least one coating (110) provided with of properties for improving light transmission through said electrode, said coating (110) having a geometric thickness of at least greater than 3 nm and at most less than or equal to 200 nm, said coating (110) comprising at least one layer of improvement of light transmission (1101) and being located between the conduction metal layer (112) and the support (10) on which said electrode (11) is deposited, characterized in that the optical thickness of the coating provided with light transmission enhancement properties (110), T ₀₁ , and the geometrical thickness of the conductive metal layer (112), T _ME , are related by the relation:

T _ME = T _ME _o + B * sin (π * T ₀₁ / T _D1 _ ₀ ) / n ³ _support

where T _{ME 0} , B and T _{01 0} are constants with T _{ME 0} having a value in the range of 10.0 to 25.0 nm, B having a value in the range of 10.0 to 16 , 5 and T _{01 0} having a value in the range of 23.9 * n _D1 nm to 28.3 * n _D1 nm with n _D1 representing the refractive index of the coating for improving light transmission at a wavelength of 550 nm, n _support represents the refractive index of the support at a wavelength of 550 nm.

2. Transparent substrate according to claim 1, characterized in that the support (10) has a refractive index, n _support , having a value at least equal to 1.2 at a wavelength of 550 nm.

3. Transparent substrate according to any one of the claims previous, characterized in that the refractive index of the light transmissive enhancement coating (110) is larger than the refractive index of the medium (10).

4. Transparent substrate according to any one of the preceding claims, characterized in that the carrier (10) has a refractive index of between 1.4 and 1.6 at a wavelength of 550 nm.

5. Transparent substrate according to claim 4, characterized in that the geometric thickness of the conduction metal layer (112) is at least 16.0 nm and at most equal to 29.0 nm and whose geometrical thickness the light transmission enhancement coating (110) is at least 20.0 nm and at most 40.0 nm.

6. Transparent substrate according to any one of claims 1 to 4, characterized in that the support has a refractive index equal to 1.5 at a wavelength of 550 nm and in that the geometrical thickness of the conduction metal layer (112) is at least 6.0 nm and at most equal to 22.0 nm and whose geometric thickness of the light-transmissive enhancement coating (110) is at least 50 , 0 nm and at most equal to 130.0 nm.

7. Transparent substrate according to any one of the preceding claims, characterized in that the electrode comprises a light transmission enhancement coating (110) comprising at least one additional crystallization layer (1102), said crystallization layer. (1102) being, relative to the support (10), the furthest layer of the stack constituting said coating (110).

8. Transparent substrate according to claim 7, characterized in that the geometric thickness of the crystallization layer (1102) is at least equal to 7% of the total geometric thickness of the coating for improving the transmission of light ( 110).

9. Transparent substrate according to any one of the preceding claims, characterized in that the electrode (11) comprises a uniform thinning layer (114) of surface electrical properties, relative to the support (10), at the top. the multilayer stack constituting said electrode (11).

10. Substrate according to any one of the preceding claims, characterized in that the electrode (11) comprises at least one additional insertion layer (113) located between the conductive metal layer (112) and the thin layer of standardization (114).

11. Transparent substrate according to claim 10, characterized in that the geometric thickness of the insertion layer (E _1n ) (113) is such that, on the one hand, its ohmic thickness is at most equal to 10 ¹² Ohm , the ohmic thickness being equal to the ratio between, on the one hand, the resistivity of the material constituting the insertion layer (p) and, on the other hand, the geometrical thickness of this same layer (1), and secondly the geometrical thickness of the insertion layer is related to the geometrical thickness of the first organic layer of the organic electroluminescent device (E _org ), the terms first organic layer designating the set of organic layers comprised between the insertion layer and the electroluminescent organic layer, by the relation: E _org = E _1n -A or A is a constant whose value is in the range from 5.0 to 75.0 nm, preferably from 20.0 to 60.0 nm, more preferably from 30.0 to 45, 0 nm.

12. Transparent substrate according to claim 10, characterized in that the geometric thickness of the insertion layer (E _1n ) (113) is such that, on the one hand, its ohmic thickness is at most equal to 10 ¹² Ohm , the ohmic thickness being equal to the ratio between, on the one hand, the resistivity of the material constituting the insertion layer (p) and, on the other hand, the geometrical thickness of this same layer (1), and secondly the geometric thickness of the insertion layer is related to the geometric thickness of the first layer organic organic electroluminescent device (E _org ), the term organic first layer designating the set of organic layers between the insertion layer and the organic electroluminescent layer, by the relation: E _org = E _1n - C or C is a constant whose value is in the range from 150.0 to 250.0 nm, preferably from 160.0 to 225.0 nm, more preferably from 75.0 to 205.0 nm.

13. transparent substrate according to any one of the preceding claims, characterized in that the conduction metal layer (112) comprises on at least one of its faces at least one sacrificial layer (111a and / or 111b).

14. Transparent substrate according to any one of the preceding claims, characterized in that the support (10) on which said electrode (11) is deposited comprises at least one functional coating (9) on the face opposite to the face on which the electrode (11) is deposited.

15. Transparent substrate according to any one of the preceding claims, characterized in that the support-side reflection (10), r _support , has a value of at least 28% and at most equal to 49%.

16. A method of manufacturing the transparent substrate according to any one of the preceding claims, characterized in that it is carried out in two stages decomposing in the following manner:

Depositing on the support (10) the coating having properties for improving the transmission of light (110),

Depositing the conduction metal layer (112) directly followed by the deposition of the various functional elements constituting the photonic system.

17. A method of manufacturing the transparent substrate according to any one of the preceding claims, characterized in that it is realized in two stages decomposing in the following way:

Depositing on the support (10) the coating (110) having properties for improving the transmission of light through the electrode (11), the metallic conduction layer (112) and the sacrificial layer (111b) , of the insertion layer (113),

Depositing the uniformization layer (114) directly followed by the deposition of the various functional elements constituting the photonic system.

18. Organic electroluminescent device comprising at least one transparent substrate according to any one of claims 1 to 15.

19. Organic electroluminescent device according to claim 18 emitting near-white light.