JP2013229186A - Organic led element, translucent substrate, and translucent substrate manufacturing method - Google Patents

Abstract

An organic LED element in which occurrence of coloring is significantly suppressed is provided.
A transparent substrate, a light scattering layer formed on the transparent substrate, a transparent first electrode layer formed on the light scattering layer, and formed on the first electrode layer An organic LED element having an organic light emitting layer and a second electrode layer formed on the organic light emitting layer, wherein the light scattering layer is dispersed in a base material made of glass and the base material A coating layer containing a metal oxide and / or a metal oxynitride is disposed between the light scattering layer and the first electrode layer, and the coating layer includes: An organic LED element characterized in that there is little difference between the degree of oxidation at the interface with the first electrode layer and the degree of internal oxidation.
[Selection] Figure 1

Description

  The present invention relates to an organic LED element, a translucent substrate, and a method for producing a translucent substrate.

  Organic LED (Light Emitting Diode) elements are widely used in displays, backlights, lighting applications, and the like.

  A general organic LED element has a first electrode (anode) disposed on a substrate, a second electrode (cathode), and an organic light emitting layer disposed between these electrodes. When a voltage is applied between the electrodes, holes and electrons are injected from each electrode into the organic light emitting layer. When the holes and electrons are recombined in the organic light emitting layer, binding energy is generated, and the organic light emitting material in the organic light emitting layer is excited by this binding energy. Since light is emitted when the excited light emitting material returns to the ground state, a light emitting (LED) element can be obtained by utilizing this.

  Usually, a transparent electrode layer such as ITO (Indium Tin Oxide) is used for the first electrode, that is, the anode, and a light metal electrode layer such as aluminum and silver is used for the second electrode, that is, the cathode. The

  Recently, a technology for forming a glass substrate by forming an uneven surface for scattering light on the surface of a glass plate on which an ITO electrode is placed and forming a glass fired film on the surface is disclosed. (Patent Document 1).

  In this method, part of the light emission generated in the organic light emitting layer is scattered by the uneven interface between the glass plate and the glass fired film, so that the amount of light confined in the organic LED element (total reflected light amount) It is disclosed that the light extraction efficiency from the organic LED element can be increased.

JP 2010-198797 A

Patent Document 1 described above shows that a protective film such as Ta ₂ O ₅ is formed on a fired glass film, and then a transparent electrode layer is provided on the protective film.

  However, in the knowledge of the inventors of the present application, when an organic LED element is to be manufactured using a light-transmitting substrate having a configuration as in Patent Document 1, that is, after forming a protective layer on a glass fired film, It has been found that when a transparent electrode layer is formed on top of this, the protective layer can often be colored. In an organic LED element provided with such a colored protective layer, the light generated in the organic light emitting layer is absorbed inside during use, and the light extraction efficiency is greatly reduced.

  This invention is made | formed in view of such a subject, and this invention aims at providing the organic LED element by which generation | occurrence | production of coloring was suppressed significantly. Moreover, it aims at providing the method of manufacturing the translucent board | substrate which can be used for such an organic LED element, and such a translucent board | substrate in this invention.

In the present invention, the transparent substrate, the light scattering layer formed on the transparent substrate, the transparent first electrode layer formed on the light scattering layer, and the first electrode layer are formed. An organic LED element having an organic light emitting layer and a second electrode layer formed on the organic light emitting layer,
The light scattering layer has a base material made of glass, and a plurality of scattering materials dispersed in the base material,
Between the light scattering layer and the first electrode layer, a coating layer containing a metal oxide and / or metal oxynitride is installed,
An organic LED element is provided in which the coating layer has a small difference between the degree of oxidation at the interface with the first electrode layer and the degree of internal oxidation.

  Here, in the organic LED element according to the present invention, the coating layer may include at least one metal element selected from the group consisting of titanium, indium, tin, tungsten, tantalum, and niobium.

  In the organic LED element according to the present invention, the coating layer may include titanium oxide and silicon oxide.

  In the organic LED element according to the present invention, the scattering material may be bubbles and / or precipitated crystals of glass constituting the base material and / or a refractory filler.

Further, in the present invention, a transparent substrate having a transparent substrate, a light scattering layer formed on the transparent substrate, and an electrode layer formed on the light scattering layer,
The light scattering layer has a base material made of glass, and a plurality of scattering materials dispersed in the base material,
Between the light scattering layer and the electrode layer, a coating layer containing a metal oxide and / or metal oxynitride is installed,
The coating layer is provided with a light-transmitting substrate characterized in that the difference between the degree of oxidation at the interface with the electrode layer and the degree of internal oxidation is small.

Furthermore, in the present invention, a method for producing a translucent substrate having a transparent substrate, a light scattering layer, and an electrode layer,
(A) forming a light scattering layer on the transparent substrate,
The light scattering layer includes a base material made of glass, and a plurality of scattering materials dispersed in the base material;
(B) installing a coating layer containing a metal oxide and / or a metal oxynitride on the light scattering layer;
(C) placing an electrode layer on the coating layer;
Have
After the step (c), a method is provided in which the coating layer has a small difference between the degree of oxidation at the interface with the electrode layer and the degree of internal oxidation.

Here, in the method according to the invention,
The step (b)
(B1) placing an organometallic solution and / or a sol-gel solution of organometallic particles on the light scattering layer;
(B2) heat-treating the sol-gel solution to form the coating layer;
You may have.

  In the method according to the present invention, in the step (b), the degree of oxidation of the metal oxide or metal oxynitride on the outermost surface side of the coating layer is the degree of oxidation of the internal metal oxide or metal oxynitride. A step of forming the coating layer so as to be larger than that.

  Further, in the method according to the present invention, in the step (c), after the step (c), the difference between the degree of oxidation at the interface with the electrode layer and the degree of internal oxidation is reduced in the coating layer. There may be a step of forming an electrode layer under such conditions.

  In the method according to the present invention, the coating layer may include at least one metal element selected from the group consisting of titanium, indium, tin, tungsten, tantalum, and niobium.

  In the method according to the present invention, the coating layer may include titanium oxide and silicon oxide.

  In the present invention, it is possible to provide an organic LED element in which the occurrence of coloring is significantly suppressed. Moreover, in this invention, it becomes possible to provide the translucent board | substrate which can be used for such an organic LED element, and the method of manufacturing such a translucent board | substrate.

It is a schematic sectional drawing of an example of the organic LED element by this invention. It is a figure for demonstrating the mechanism assumed about the coloring phenomenon of a coating layer. It is the graph which showed the relationship between the oxygen content in the film-forming atmosphere of a 1st electrode layer, and the absorption factor of the obtained translucent board | substrate. It is the flowchart which showed roughly an example of the manufacturing method of the organic LED element by this invention. It is the graph which showed the measurement result of the absorptivity obtained in the 1st translucent board-the 3rd translucent board.

(Organic LED device according to the present invention)
Hereinafter, the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a schematic cross-sectional view of an example of an organic LED element according to the present invention.

  As shown in FIG. 1, the organic LED element 100 according to the present invention includes a transparent substrate 110, a light scattering layer 120, a coating layer 130, a first electrode (anode) layer 140, an organic light emitting layer 150, Two electrode (cathode) layers 160 are stacked in this order.

  The transparent substrate 110 has a role of supporting each layer constituting the organic LED element on the top.

  The light scattering layer 120 includes a glass base material 121 having a first refractive index, and a plurality of scattering materials 124 having a second refractive index different from the base material 121 and dispersed in the base material 121. It consists of. The thickness of the light scattering layer 120 is, for example, in the range of 5 μm to 50 μm.

  The first electrode layer 140 is made of a transparent metal oxide thin film such as ITO (indium tin oxide), for example, and has a thickness of about 50 nm to 1.0 μm. On the other hand, the second electrode layer 160 is made of a metal such as aluminum or silver.

  In general, the organic light emitting layer 150 includes a plurality of layers such as an electron transport layer, an electron injection layer, a hole transport layer, and a hole injection layer in addition to the light emitting layer.

  In the example of FIG. 1, the lower surface of the organic LED element 100 (that is, the exposed surface of the transparent substrate 110) is the light extraction surface 170.

  The light scattering layer 120 has a role of effectively scattering the light generated from the organic light emitting layer 150 and reducing the amount of light totally reflected in the organic LED element 100. Therefore, in the organic LED element 100 having the configuration of FIG. 1, the amount of light emitted from the light extraction surface 170 can be improved.

  Here, in the organic LED element 100 according to the present invention, the coating layer 130 is provided between the light scattering layer 120 and the first electrode layer 140.

  In the present application, the “coating layer (130)” means a general term for layers disposed between the first electrode layer and the light scattering layer. Such a “coating layer” (130) smoothes the surface of the light scattering layer and facilitates the subsequent film formation process, and / or during the patterning of the first electrode layer. Furthermore, it functions as an anti-etching barrier that prevents elution and deterioration of the light scattering layer. The covering layer 130 is composed of a metal oxide or a metal oxynitride (hereinafter, both are collectively referred to as “metal oxide”).

As described above, Patent Document 1 is configured by forming a protective film such as Ta ₂ O ₅ as a “coating layer” on a glass fired film, and then setting a transparent electrode layer thereon. A translucent substrate is shown.

  However, the inventors of the present application, when trying to manufacture an organic LED element using a translucent substrate having a configuration as in Patent Document 1, that is, after forming a coating layer on a glass fired film, When the transparent electrode layer is formed on the upper part, it has been noticed that the coating layer is often colored.

  When the completed organic LED element has a coating layer with such coloring, the light generated in the organic light emitting layer is absorbed inside when the organic LED element is used, and the light extraction efficiency is greatly reduced. The problem of doing so will arise.

  The inventors of the present application have conducted research and development on the generation mechanism after finding such a problem of coloring the coating layer. As a result, it was found that the coloring phenomenon of the coating layer is largely related to the change in the degree of oxidation of the surface of the coating layer before and after the formation of the first electrode layer.

  Hereinafter, with reference to FIG. 2, a mechanism assumed as a coloring phenomenon of the coating layer according to the study of the present inventors will be described.

  FIG. 2A shows a state in which a coating layer 30 made of a metal oxide is formed on the light scattering layer 20. FIG. 2B shows a state after the first electrode layer 40 is formed on the coating layer 30.

  As shown in FIG. 2A, in the state immediately after the coating layer 30 is formed on the light scattering layer 20, that is, before the first electrode layer 40 is installed, the coating layer 30 has a thickness. It has a relatively uniform oxidation state with respect to the direction. Therefore, the degree of oxidation in the thickness direction of the metal oxide constituting the coating layer 30 is substantially constant.

  Next, the first electrode layer 40 is formed on the coating layer 30.

  Here, since the film formation process of the first electrode layer 40 is normally performed in a reducing atmosphere, the first electrode layer 40 tends to be deficient in oxygen. For this reason, when the first electrode layer 40 is formed on the upper portion of the covering layer 30, some oxygen constituting the metal oxide is formed on the first electrode layer 40 side on the outermost surface of the covering layer 30. Gravitate.

  As a result, after the film formation of the first electrode layer 40, as shown in FIG. 2B, the altered layer 80 is formed in the vicinity of the interface 90 of the coating layer 30 with the first electrode layer 40.

  More specifically, in the vicinity of the interface 90 between the first electrode layer 40 and the coating layer 30, the valence state of the metal ions constituting the metal oxide of the coating layer 30 changes and the valence of the metal ions is lower. State (for example, tetravalent to trivalent, tetravalent to divalent, etc.). As a result, the altered layer 80 having a different degree of oxidation of the metal oxide from the inner side is formed on the outermost surface side of the coating layer 30.

  Here, normally, metal ions tend to increase light absorption in a low valence state. Therefore, it is considered that the coating layer 30 is colored due to the generation of the altered layer 80.

  The inventors of the present application, based on the generation mechanism of the coloring phenomenon of the coating layer 30, suppresses the generation of the altered layer 80 as shown in FIG. The inventors have found that generation can be avoided and have arrived at the present invention.

  That is, in the organic LED element 100 according to the present invention, the coating layer 130 after the first electrode layer 140 is formed is an interface with the first electrode layer 140 (hereinafter also referred to as the “outermost surface” of the coating layer 130). ) Side oxidation degree and the degree of oxidation inside the coating layer 130 are small.

  By making the coating layer 130 have such a configuration, it is possible to provide the organic LED element 100 in which the occurrence of coloring is significantly suppressed.

In addition, in the coating layer 130 after the first electrode layer 140 is formed, a method for reducing the difference in the degree of oxidation between the outermost surface side and the inner side is not particularly limited. It can be roughly divided into two types.
(1) At the stage of forming the coating layer 130, the outermost metal oxide is previously brought into an “oxygen-rich” state; and (2) When the first electrode layer 140 is formed The film forming conditions are “oxygen-rich” conditions.

  In the case of the method (1), the outermost surface of the covering layer 130 is already in an oxygen-excess state before the first electrode layer 140 is formed. Accordingly, even when oxygen is transferred from the coating layer 130 to the first electrode layer 140 as described above at the stage of forming the first electrode layer 140, the outermost surface of the coating layer 130 is still not formed. Sufficient oxygen remains. For this reason, generation | occurrence | production of the altered layer 80 can be suppressed significantly.

  On the other hand, when the film-forming conditions for forming the first electrode layer 140 are oxygen-rich conditions as in the method (2), oxygen is transferred from the coating layer 130 to the first electrode layer 140. Is less likely to occur. Therefore, also in this case, the generation of the altered layer 80 can be significantly suppressed.

  Note that the above method is merely an example, and in addition, in the evaluation after the first electrode layer 140 is formed by various methods, there is a difference in the degree of oxidation between the outermost surface side and the inner side. A small covering layer 130 can be formed. For example, the methods (1) and (2) may be combined.

  Hereinafter, the effect of the method (2) will be described in detail with reference to FIG.

  FIG. 3 shows an absorptance in a wavelength range of 250 nm to 700 nm in a sample obtained by forming the first electrode layer 130 after forming the coating layer 130 on the transparent substrate 110 having the light scattering layer 120. The measurement results are shown.

  Note that the first electrode layer 130 was formed of ITO by a sputtering method. The oxygen flow rate during the ITO film formation is 2.0 sccm (seventh translucent substrate), 3.0 sccm (sixth translucent substrate), 4.0 sccm (fifth translucent substrate), and 5 0.0 sccm (fourth translucent substrate).

  From this result, it can be seen that by increasing the oxygen flow rate to the atmosphere during ITO film formation, that is, by making the atmosphere during ITO film formation rich in oxygen, the absorption of the obtained sample is reduced. For example, at a wavelength of 550 nm, the absorption rate is about 15% when the oxygen flow rate during ITO film formation is 2.0 sccm, but when the oxygen flow rate during ITO film formation is 5.0 sccm, the absorption rate is Decreased to about 9%.

  From this result, at the stage after the first electrode layer 140 is formed, the difference between the degree of oxidation on the interface side with the first electrode layer 140 and the degree of oxidation on the inner side of the coating layer 130 is reduced. It can be seen that by forming the coating layer 130 on the organic LED element 100, the occurrence of coloring can be significantly suppressed.

  Next, the detail of each layer which comprises the organic LED element 100 by this invention is demonstrated.

(Transparent substrate 110)
The transparent substrate 110 is made of a material having a high transmittance for visible light. The transparent substrate 110 may be a glass substrate or a plastic substrate, for example.

  Examples of the material of the glass substrate include inorganic glass such as alkali glass, non-alkali glass, and quartz glass. Examples of the plastic substrate material include polyester, polycarbonate, polyether, polysulfone, polyethersulfone, polyvinyl alcohol, and fluorine-containing polymers such as polyvinylidene fluoride and polyvinyl fluoride.

  The thickness of the transparent substrate 110 is not particularly limited, but may be in the range of 0.1 mm to 2.0 mm, for example. Considering strength and weight, the thickness of the transparent substrate 110 is preferably 0.5 mm to 1.4 mm.

(Light scattering layer 120)
The light scattering layer 120 includes a base material 121 and a plurality of scattering materials 124 dispersed in the base material 121. The base material 121 has a first refractive index, and the scattering material 124 has a second refractive index different from that of the base material.

  The amount of the scattering material 124 in the light scattering layer 120 is preferably small from the inside to the outside of the light scattering layer 120. In this case, highly efficient light extraction can be realized.

  The base material 121 is made of glass, and an inorganic glass such as soda lime glass, borosilicate glass, alkali-free glass, and quartz glass is used as the glass material.

  The scattering material 124 includes, for example, bubbles, precipitated crystals, material particles different from the base material, phase separation glass, and the like. A phase-separated glass refers to a glass composed of two or more types of glass phases.

  The difference between the refractive index of the base material 121 and the refractive index of the scattering material 124 should be large. For this purpose, it is preferable to use high refractive index glass as the base material 121 and use bubbles as the scattering material 124. .

Because of the high refractive index glass for the base material 121, one or more components of P ₂ O ₅ , SiO ₂ , B ₂ O ₃ , GeO ₂ , and TeO ₂ are selected as the network former. As high refractive index components, TiO ₂ , Nb ₂ O ₅ , WO ₃ , Bi ₂ O ₃ , La ₂ O ₃ , Gd ₂ O ₃ , Y ₂ O ₃ , ZrO ₂ , ZnO, BaO, PbO, and Sb ₂ One or more components of O ₃ may be selected. Furthermore, in order to adjust the characteristics of the glass, alkali oxides, alkaline earth oxides, fluorides, and the like may be added within a range that does not affect the refractive index.

Accordingly, examples of the glass system constituting the base material 121 include B ₂ O ₃ —ZnO—La ₂ O ₃ system, P ₂ O ₅ —B ₂ O ₃ —R ′ ₂ O—R ”O—TiO ₂ —. Nb ₂ O ₅ —WO ₃ —Bi ₂ O ₃ system, TeO ₂ —ZnO system, B ₂ O ₃ —Bi ₂ O ₃ system, SiO ₂ —Bi ₂ O ₃ system, SiO ₂ —ZnO system, B ₂ O ₃ -ZnO _system, like P ₂ O 5 -ZnO system. here, R 'is an alkali metal element, R "represents an alkaline earth metal element. In addition, the above material system is only an example, and if it is the structure which satisfy | fills the said conditions, the material to be used will not be restricted especially.

  The color of light emission can be changed by adding a colorant to the base material 121. As the colorant, transition metal oxides, rare earth metal oxides, metal colloids, and the like can be used alone or in combination.

(Coating layer 130)
The covering layer 130 is at least partially formed of metal oxide or metal oxynitride.

  The metal species constituting the metal oxide or metal oxynitride is not particularly limited, but the metal species may include, for example, titanium, indium, tin, tungsten, tantalum, and / or niobium.

The covering layer 130 may further include silicon oxide (SiO ₂ ).

  For example, the coating layer 130 may be a layer composed of a mixture of titanium oxide and silicon oxide. In this case, the ratio of titanium oxide and silicon oxide is not particularly limited, but the ratio between the two (titanium oxide: silicon oxide) may be, for example, in the range of 80:20 to 20:80. . In particular, the ratio of titanium oxide: silicon oxide is preferably in the range of 75:25 to 40:60 by weight.

  In order to further improve the extraction efficiency, the refractive index of the coating layer 130 is preferably lower than that of the electrode 140. Specifically, the difference between the refractive index of the coating layer 130 and the refractive index of the light scattering layer 120 is preferably 0.2 or less, more preferably 0.13 or less, and more preferably 0.11 or less.

  The film thickness of the coating layer 130 is not particularly limited. The film thickness of the coating layer 130 may be in the range of 100 nm to 500 μm, for example.

  The coating layer 130 may be formed by either a wet coating method or a dry coating method.

  Here, it should be noted that in the present invention, the coating layer 130 has a small difference between the degree of oxidation at the interface with the first electrode layer 140 and the degree of internal oxidation. That is, in the present invention, the above-mentioned deteriorated layer 80 is hardly formed on the outermost surface of the coating layer 130, and this can significantly suppress the problem of coloring.

  In addition, when the characteristic (light extraction efficiency) as the organic LED element 100 is taken into consideration, the refractive index on the interface side with the first electrode layer 140 and the refractive index on the inner side of the coating layer 130 are close to each other. Is preferred.

(First electrode layer 140)
The first electrode layer 140 is required to have a light transmissivity of 80% or more in order to extract light generated in the organic light emitting layer 150 to the outside. Also, a high work function is required to inject many holes.

The first electrode layer 140 includes, for example, ITO, SnO ₂ , ZnO, IZO (Indium Zinc Oxide), AZO (ZnO—Al ₂ O ₃ : zinc oxide doped with aluminum), GZO (ZnO—Ga _2). Materials such as O ₃ : zinc oxide doped with gallium), Nb-doped TiO ₂ , and Ta-doped TiO ₂ are used.

  The thickness of the first electrode layer 140 is preferably 100 nm or more.

The refractive index of the first electrode layer 140 is in the range of 1.75 to 2.2. For example, when ITO is used as the first electrode layer 140, the refractive index of the first electrode layer 140 can be decreased by increasing the carrier concentration. Commercially available ITO contains 10 wt% SnO ₂ as standard, but the refractive index of ITO can be lowered by further increasing the Sn concentration. However, as the Sn concentration increases, the carrier concentration increases, but the mobility and transmittance decrease. Therefore, it is necessary to determine the Sn amount in consideration of the overall balance.

  The refractive index of the first electrode layer 140 is preferably determined in consideration of the refractive index of the base material 121 constituting the light scattering layer 120 and the refractive index of the second electrode layer 160. In consideration of waveguide calculation, the reflectance of the second electrode layer 160, and the like, the difference in refractive index between the first electrode layer 140 and the base material 121 is preferably 0.2 or less.

  Here, for reference, the refractive index of each member between the light scattering layer 120 and the first electrode layer 140 will be described. However, the following combinations of refractive indexes are merely examples, and each member may have other refractive indexes.

  The refractive index of the light scattering layer 120 is, for example, in the range of 1.8 to 2.0 (for example, about 1.84). Moreover, the refractive index of the coating layer 130 is, for example, in the range of 1.7 to 2.0 (for example, about 1.75). Furthermore, the refractive index of the first electrode layer 140 is, for example, in the range of 1.8 to 2.2 (for example, about 1.8).

(Organic light emitting layer 150)
The organic light emitting layer 150 is a layer having a light emitting function, and is generally composed of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. However, it is obvious to those skilled in the art that the organic light emitting layer 150 does not necessarily have all of the other layers as long as it has a light emitting layer. In a normal case, the refractive index of the organic light emitting layer 150 is in the range of 1.7 to 1.8.

  The hole injection layer preferably has a small difference in ionization potential in order to lower the hole injection barrier from the first electrode layer 140. When the charge injection efficiency from the electrode to the hole injection layer increases, the drive voltage of the organic LED element 100 decreases and the charge injection efficiency increases.

As the material of the hole injection layer, a high molecular material or a low molecular material is used. Among the polymer materials, polyethylene dioxythiophene (PEDOT: PSS) doped with polystyrene sulfonic acid (PSS) is often used, and among the low molecular materials, phthalocyanine-based copper phthalocyanine (CuPc) is widely used. .
The hole transport layer serves to transport holes injected from the hole injection layer to the light emitting layer. Examples of the hole transport layer include a triphenylamine derivative, N, N′-bis (1-naphthyl) -N, N′-diphenyl-1,1′-biphenyl-4,4′-diamine (NPD), N , N′-diphenyl-N, N′-bis [N-phenyl-N- (2-naphthyl) -4′-aminobiphenyl-4-yl] -1,1′-biphenyl-4,4′-diamine ( NPTE), 1,1′-bis [(di-4-tolylamino) phenyl] cyclohexane (HTM2), and N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′- Diphenyl-4,4′-diamine (TPD) or the like is used.

The thickness of the hole transport layer is, for example, in the range of 10 nm to 150 nm. The voltage of the organic LED element can be lowered as the thickness of the hole transport layer is reduced, but it is usually in the range of 10 nm to 150 nm due to the problem of short circuit between electrodes.
The light emitting layer has a role of providing a field where the injected electrons and holes are recombined. As the organic light emitting material, a low molecular weight or high molecular weight material is used.

  Examples of the light emitting layer include tris (8-quinolinolato) aluminum complex (Alq3), bis (8-hydroxy) quinaldine aluminum phenoxide (Alq′2OPh), and bis (8-hydroxy) quinaldine aluminum-2,5- Dimethylphenoxide (BAlq), mono (2,2,6,6-tetramethyl-3,5-heptanedionate) lithium complex (Liq), mono (8-quinolinolato) sodium complex (Naq), mono (2, 2,6,6-tetramethyl-3,5-heptanedionate) lithium complex, mono (2,2,6,6-tetramethyl-3,5-heptanedionate) sodium complex and bis (8-quinolinolate) Metal complexes of quinoline derivatives such as calcium complex (Caq2), tetraphenyl butadiene, phenyl key Kudrin (QD), anthracene, perylene, as well as fluorescent substance such as coronene.

As the host material, a quinolinolate complex may be used, and in particular, an aluminum complex having 8-quinolinol and a derivative thereof as a ligand may be used.
The electron transport layer serves to transport electrons injected from the electrode. Examples of the electron transport layer include quinolinol aluminum complex (Alq3), oxadiazole derivatives (for example, 2,5-bis (1-naphthyl) -1,3,4-oxadiazole (END), and 2- ( 4-t-butylphenyl) -5- (4-biphenyl))-1,3,4-oxadiazole (PBD), triazole derivatives, bathophenanthroline derivatives, silole derivatives, and the like.
The electron injection layer is configured by, for example, providing a layer doped with an alkali metal such as lithium (Li) or cesium (Cs) at the interface with the second electrode layer 160.

(Second electrode layer 160)
For the second electrode layer 160, a metal having a small work function or an alloy thereof is used. The second electrode layer 160 may be, for example, an alkali metal, an alkaline earth metal, a metal belonging to Group 3 of the periodic table, or the like. For the second electrode layer 160, for example, aluminum (Al), magnesium (Mg), or an alloy thereof is used.

Also, a laminated electrode in which aluminum (Al) is deposited on a thin film of aluminum (Al), magnesium silver (MgAg), lithium fluoride (LiF), or lithium oxide (Li ₂ O) may be used. good. Furthermore, a laminated film of calcium (Ca) or barium (Ba) and aluminum (Al) may be used.

(Method for producing organic LED element according to the present invention)
Next, with reference to FIG. 4, an example of the manufacturing method of the organic LED element by this invention is demonstrated. FIG. 4 shows a schematic flow chart when manufacturing the organic LED element according to the present invention.

As shown in FIG. 4, the manufacturing method of the organic LED element according to the present invention includes:
(A) forming a light scattering layer on the transparent substrate (step S110);
(B) installing a coating layer on the light scattering layer (step S120);
(C) installing a first electrode layer on the coating layer (step S130);
(D) installing an organic light emitting layer on the first electrode layer (step S140);
(E) installing a second electrode layer on the organic light emitting layer (step S150);
Have Hereinafter, each step will be described in detail. In the following description, the reference numerals shown in FIG. 1 are used as reference numerals for each member for the sake of clarity.

(Step S110)
First, a transparent substrate is prepared. As described above, a glass substrate or a plastic substrate is usually used as the transparent substrate.

  Next, a light scattering layer in which a scattering substance is dispersed in a glass base material is formed on the transparent substrate. The method for forming the light scattering layer is not particularly limited, but here, a method for forming the light scattering layer by the “frit paste method” will be particularly described. However, it will be apparent to those skilled in the art that the light scattering layer may be formed by other methods.

  In the frit paste method, a paste containing a glass material called a frit paste is prepared (preparation process), this frit paste is applied to the surface of the substrate to be installed, patterned (pattern formation process), and the frit paste is then baked. This is a method of forming a desired glass film on the surface of the substrate to be installed by performing (firing process). Hereinafter, each process will be briefly described.

(Preparation process)
First, a frit paste containing glass powder, resin, solvent and the like is prepared.

A glass powder is comprised with the material which finally forms the base material of a light-scattering layer. The composition of the glass powder is not particularly limited as long as desired scattering characteristics can be obtained, and the glass powder can be frit pasted and fired. The composition of the glass powder, for _example, 20 to 30 _mol% of _{P 2 O 5, B 2 O} 3 to 3~14mol%, 10~20mol% of _Bi 2 _{O 3,} a _{TiO 2 3~15mol%, Nb 2 O} 5 10 to 20 mol%, WO ₃ to 5 to 15 mol%, the total amount of Li ₂ O, Na ₂ O and K ₂ O is 10 to 20 mol%, and the total amount of the above components is 90 mol% or more. May be. Further, SiO ₂ is _0~30mol%, B 2 _{O 3} is 10~60mol%, ZnO is 0~40mol%, _Bi 2 _{O 3} is _0~40mol%, P 2 _{O 5} is 0~40mol%, alkali metal oxide A thing is 0-20 mol%, and the total amount of the above component may be 90 mol% or more. The particle size of the glass powder is, for example, in the range of 1 μm to 100 μm.

  In order to control the thermal expansion characteristics of the finally obtained light scattering layer, a predetermined amount of filler may be added to the glass powder. For example, particles such as zircon, silica, or alumina are used as the filler, and the particle size is usually in the range of 0.1 μm to 20 μm.

  Examples of the resin include ethyl cellulose, nitrocellulose, acrylic resin, vinyl acetate, butyral resin, melamine resin, alkyd resin, and rosin resin. Note that the addition of butyral resin, melamine resin, alkyd resin, and rosin resin improves the strength of the frit paste coating film.

  A solvent has a role which melt | dissolves resin and adjusts a viscosity. Examples of the solvent include ether solvents (butyl carbitol (BC), butyl carbitol acetate (BCA), dipropylene glycol butyl ether, tripropylene glycol butyl ether, butyl cellosolve), alcohol solvents (α-terpineol, pine oil). , Ester solvents (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), phthalate esters solvents (DBP (dibutyl phthalate), DMP (dimethyl phthalate), DOP (dioctyl phthalate)) is there. Mainly used are α-terpineol and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate). DBP (dibutyl phthalate), DMP (dimethyl phthalate), and DOP (dioctyl phthalate) also function as a plasticizer.

  In addition, a surfactant may be added to the frit paste to adjust viscosity and promote frit dispersion. Moreover, you may use a silane coupling agent for surface modification.

  Next, these raw materials are mixed to prepare a frit paste in which glass raw materials are uniformly dispersed.

(Pattern formation process)
Next, the frit paste prepared by the above-described method is applied on a transparent substrate and patterned. The application method and the patterning method are not particularly limited. For example, a frit paste may be pattern-printed on a transparent substrate using a screen printer. Alternatively, a doctor blade printing method or a die coat printing method may be used.

  Thereafter, the frit paste film is dried.

(Baking process)
Next, the frit paste film is baked. Usually, firing is performed in two steps. In the first step, the resin in the frit paste film is decomposed and disappeared, and in the second step, the glass powder is softened and sintered.

  The first step is performed by maintaining the frit paste film in a temperature range of 200 ° C. to 400 ° C. in an air atmosphere. However, the processing temperature varies depending on the resin material contained in the frit paste. For example, when the resin is ethyl cellulose, the treatment temperature may be about 350 ° C. to 400 ° C., and when the resin is nitrocellulose, the treatment temperature may be about 200 ° C. to 300 ° C. The processing time is usually about 30 minutes to 1 hour.

  The second step is performed by maintaining the frit paste film in the temperature range of the softening temperature ± 30 ° C. of the glass powder contained in the atmosphere. The processing temperature is, for example, in the range of 450 ° C to 600 ° C. Further, the processing time is not particularly limited, but is, for example, 30 minutes to 1 hour.

  After the second step, the glass powder is softened and sintered to form a base material for the light scattering layer. Further, the scattering material uniformly dispersed in the base material can be obtained by the scattering material encapsulated in the frit paste film, for example, due to the bubbles present therein.

  Thereafter, by cooling the transparent substrate, a light scattering layer having a surface whose side surface portion is inclined at a gentler angle than a right angle from the upper surface toward the bottom surface is formed.

  The thickness of the finally obtained light scattering layer may be in the range of 5 μm to 50 μm.

(Step S120)
Next, a coating layer is placed on the light scattering layer obtained in the above step. Generally, a coating layer is comprised with a metal oxide or a metal oxynitride.

  The coating layer is formed by, for example, a dry coating method. Alternatively, the coating layer may be formed by, for example, a wet coating method. The type of wet coating method is not particularly limited, but here, a method of forming a coating layer using a sol-gel solution containing an organometallic solution and organometallic particles will be described. However, the coating layer may be formed by other wet coating methods.

  When forming a coating layer using a sol-gel solution containing an organometallic solution and organometallic particles, a step of applying the sol-gel solution on the light scattering layer (application step) and a step of drying the applied sol-gel layer (drying) The coating layer is formed through a step) and a step of heat-treating the dried sol-gel layer (heat treatment step). Hereinafter, each process will be briefly described.

(Coating process)
First, a sol-gel solution is applied on the light scattering layer. The sol-gel solution includes an organometallic solution and organometallic particles.

  The organometallic solution is an alkoxide or organic complex of titanium, niobium, zirconium, tantalum, silicon. In addition, the organometallic solution may have a silicon oxide source such as organosilane.

  The organometallic particles may include, for example, organotitanium, organoniobium, organozirconium, and / or organotantalum oligomers and particles. The solvent of the sol-gel solution is not particularly limited, and water and / or an organic solvent may be used as the solvent.

  The organic metal solution is not limited to the following specific examples. For example, titanium tetramethoxide, titanium tetraethoxide, titanium tetranormal propoxide, titanium tetraisopropoxide, titanium tetranormal butoxide, titanium tetraisobutoxide, titanium Diisopropoxy dinormal butoxide, titanium ditertiary butoxy diisopropoxide, titanium tetratertiary butoxide, titanium tetrapentoxide, titanium tetrahexoxide, titanium tetraheptoxide, titanium tetraisooctyl oxide, tetrastearyl alkoxy titanate Titanium alkoxide, titanium tetracyclooxide such as titanium tetracyclohexoxide, titanium aryloxide such as titanium tetraphenoxide, hydroxy Titanium acylates such as Nstearate, dipropoxy titanium bis (acetylacetonate), titanium tetraacetylacetonate, titanium di-2-ethylhexoxybis (2-ethyl-3-hydroxyhexoxide), titanium diisopropoxybis (Ethyl acetoacetate), titanium diisopropoxybis (triethanolaminate), titanium lactate ammonium salt, titanium chelate such as titanium lactate, alkoxy zirconium such as zirconium tetranormal propoxide, zirconium tetranormal butoxide, zirconium tributoxy monostearate Rate, zirconium acylates such as zirconium chloride and zirconium aminocarboxylate, zirconium tetraacetylacetonate, zirconium tributoxy Zirconium chelates such as monoacetylacetonate, zirconium dibutoxybis (ethylacetoacetate), zirconium tetraacetylacetonate, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, hexyltrimethoxy Silane, decyltrimethoxysilane, vinyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3- (glycidyloxy) propyltrimethoxysilane, trifluoropropyl Trimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxy Lan, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-3- (aminoethyl) -3-aminopropyltrimethoxysilane, N-phenyl-3 -Aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, 3-methacrylic Roxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, hexyltriethoxysilane, vinyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, 3-ureido Propyltriethoxysilane, 3-isocyanatopropyltriethoxysilane, tetranormalpropoxysilane, tetraisopropoxysilane, tetranormalbutoxysilane, tetraisobutoxysilane, diisopropoxydinormalbutoxysilane, ditertiarybutoxydiisopropoxysilane, tetra Alkoxysilanes such as tertiary butoxysilane, tetrapentoxysilane, tetrahexoxysilane, tetraheptoxysilane, tetraisooctyloxysilane, tetrastearylalkoxysilane, hexamethyldi Examples include those composed of silazanes such as silazane and alcohol, ether, ketone, and hydrocarbon solvents.

  It is more preferable to use titanium, niobium, zirconium, tantalum, silicon alkoxides and chelate compounds such as these organic metals to condense titanium, niobium, zirconium, tantalum, and silicon compound oligomers. The method of condensation is not particularly limited, but it is preferable to react water in an alcohol solution. By condensing, cracks during film formation can be suppressed, and a thick film can be formed. In particular, by mixing an organosilane compound, cracks during film formation can be suppressed and a thick film can be formed. In addition, the refractive index of the film can be adjusted.

  The method for applying the sol-gel solution is not particularly limited. The sol-gel solution may be applied onto the light scattering layer using a general coating film forming apparatus (spin coater, applicator, etc.).

  The method for applying the sol-gel solution is not particularly limited. The sol-gel solution may be applied on the light scattering layer using a general coating film forming apparatus (such as an applicator).

(Drying process)
Next, the sol-gel liquid applied on the light scattering layer is dried to form a sol-gel layer. Drying conditions are not particularly limited. Drying may be performed, for example, by holding a transparent substrate with a light scattering layer coated with a sol-gel solution at a temperature of 80 ° C. to 120 ° C. for about 1 minute to 1 hour.

(Heat treatment process)
Next, the dried sol-gel layer is kept at a high temperature. As a result, the solvent in the sol-gel layer is completely evaporated, decomposed, and / or burned out, and the organometallic compound in the sol-gel layer is oxidized and bonded to form a coating layer.

  Thereby, for example, a coating layer composed of a mixture of titania and silica or the like is formed.

  The conditions for the heat treatment are not particularly limited. For example, the holding temperature may be in the range of 450 ° C. to 550 ° C., and the holding time may be in the range of 10 minutes to 24 hours.

  The coating layer is formed by the above steps.

  Here, as described above, the covering layer 130 has a degree of oxidation on the interface side with the first electrode layer 140 and the inner side of the covering layer 130 in the stage after the first electrode layer 140 is formed. It has the characteristic that there is little difference with the degree of oxidation.

  By making the coating layer 130 have such a characteristic, the occurrence of coloring is significantly suppressed, and in the finally obtained organic LED element 100, the absorption of light inside is reduced, and the light extraction efficiency is improved. It becomes possible to raise significantly.

Note that the coating layer 130 having such characteristics can be broadly formed by the following two methods.
(First method) In the stage of forming the coating layer 130, the metal oxide on the outermost surface side is previously brought into an “oxygen-rich” state; and (second method) the first electrode layer The film formation conditions when forming the film 140 are “oxygen-rich” conditions.

  Hereinafter, the first and second methods will be briefly described.

(First method)
In the first method, before the first electrode layer 140 is formed, the outermost surface of the coating layer 130 is previously in an oxygen-excess state.

  The coating layer 130 in such a state can be easily obtained, for example, by forming an oxide film on the outermost surface of the coating layer by a dry coating process or the like under an oxygen-rich condition. Various methods such as a sputtering method, a physical vapor deposition method, and a chemical vapor deposition method can be applied as the dry coating process.

  When the coating layer 130 has such an oxygen-excessive outermost surface, the coating layer 130 to the first electrode layer 140 as described above is formed at the subsequent stage of film formation of the first electrode layer 140. Even if oxygen moves, sufficient oxygen still remains on the outermost surface of the coating layer 130. For this reason, generation | occurrence | production of the altered layer 80 can be suppressed significantly.

(Second method)
In the second method, the first electrode layer 140 is formed under the condition that the film formation condition for forming the first electrode layer 140 is “oxygen-rich”.

  Therefore, details of this process will be described in step S130. However, when the film forming conditions for forming the first electrode layer 140 are oxygen-rich conditions as in this method, the coating layer 130 is changed to the first one. The movement of oxygen to one electrode layer 140 is less likely to occur. Therefore, also in this case, the generation of the altered layer 80 can be significantly suppressed.

(Step S130)
Next, a transparent first electrode layer (anode) 140 is placed on the coating layer 130 obtained in the above step.

  The method for installing the first electrode layer 140 is not particularly limited, and for example, a film forming method such as a sputtering method, a vapor deposition method, and a vapor phase film forming method may be used.

  As described above, the material of the first electrode layer 140 may be ITO or the like. In addition, the thickness of the first electrode layer 140 is not particularly limited, and the thickness of the first electrode layer 140 may be, for example, in the range of 50 nm to 1.0 μm.

  Further, the first electrode layer 140 may be patterned by an etching process or the like.

  In addition, when the second method as described in step S120 described above is employed, step S130 is performed under “oxygen-rich” conditions.

  For example, in the case where the first electrode layer 140 such as ITO is formed by a sputtering method, the first electrode layer 140 is formed under a film formation atmosphere in which oxygen is more excessive than usual. Alternatively, when the first electrode layer 140 such as ITO is formed by a chemical vapor deposition method, the formation of the first electrode layer 140 is performed under the condition that the ratio of oxygen to the metal in the raw material is increased. Film processing is performed.

  This makes it difficult for an altered layer to form on the outermost surface of the coating layer 130 during the formation of the first electrode layer 140. Therefore, the problem of coloring the coating layer 130 can be significantly suppressed.

  The laminate having the transparent substrate, the light scattering layer, the coating layer, and the first electrode layer obtained through the steps so far is referred to as a “translucent substrate”. The specifications of the organic light-emitting layer, the second electrode layer, and the like installed after the next step vary depending on the application application of the finally obtained organic LED element. Therefore, conventionally, the “translucent substrate” is often distributed in the market as an intermediate product in this state, and the subsequent steps are often omitted.

(Step S140)
Next, an organic light emitting layer is provided so as to cover the first electrode layer. The installation method of the organic light emitting layer is not particularly limited, and for example, a vapor deposition method and / or a coating method may be used.

(Step S150)
Next, a second electrode layer is disposed on the organic light emitting layer. The installation method of the second electrode layer is not particularly limited, and for example, an evaporation method, a sputtering method, a vapor deposition method, or the like may be used.

  Through the above steps, the organic LED element 100 as shown in FIG. 1 is manufactured. However, the manufacturing method of the organic LED element described above is an example, and it is obvious to those skilled in the art that the organic LED element may be manufactured by other methods.

  Next, examples of the present invention will be described.

  Various transparent substrates were manufactured by the following method and their characteristics were evaluated.

(Manufacture of various transparent substrates)
A soda-lime substrate having a length of 50 mm, a width of 50 mm, and a thickness of 0.55 mm was prepared as a transparent substrate. Moreover, various layers were formed on this transparent substrate, and a total of three types of translucent substrates were produced.

(First translucent substrate)
First, a light scattering layer was formed on a transparent substrate.

  The light scattering layer was formed by the following method.

(Formation of light scattering layer)
A raw material for the light scattering layer was prepared by the following method.

  First, a mixed powder having the composition shown in Table 1 was prepared and dissolved. The dissolution was carried out by holding at 1050 ° C. for 1.5 hours and then holding at 950 ° C. for 30 minutes. Thereafter, the melt was cast into twin rolls to obtain flaky glass.

屈折率計（カルニュー光学工業社製、商品名：ＫＲＰ−２）を用いて、フレーク状ガラスの屈折率を測定したところ、フレーク状ガラスのｄ線（５８７．５６ｎｍ）での屈折率ｎｄは、１．８４であった。

Using a refractometer (trade name: KRP-2, manufactured by Kalnew Optical Industry Co., Ltd.), the refractive index nd at the d-line (587.56 nm) of the flaky glass was measured. 1.84.

Next, this flaky glass was dry-pulverized with a zirconia planetary ball mill for 2 hours to prepare glass powder having an average particle size (d ₅₀ : particle size of 50% integrated value, unit μm) of 1 to 3 μm.

  Next, 15 vol% of silica spheres having a diameter of 3 μm were added to 75 g of this glass powder, and kneaded with 25 g of an organic vehicle (a solution of about 10% by mass of ethyl cellulose in a-terpineol or the like) to prepare a glass paste. Further, this glass paste was printed on a soda lime substrate using a screen printer. As a result, a pattern having two circular scattering layers having a diameter of 10 mmφ was formed on the soda lime substrate. After screen printing, the soda lime substrate was dried at 120 ° C. for 10 minutes.

  The soda lime substrate was heated to 450 ° C. over 45 minutes, held at 450 ° C. for 10 hours, then heated to 575 ° C. in 12 minutes, held at 575 ° C. for 40 minutes, and then to room temperature in 3 hours. The temperature dropped. The film thickness after firing was 15.0 μm. Next, the above paste containing no silica sphere was prepared in the same manner as described above, and a cover layer was similarly formed on the scattering layer. Here, the film thickness of the cover layer was 15.0 μm. As a result, a light scattering layer with a cover layer was formed on the soda lime substrate.

  The total thickness of the light scattering layer was 30 μm.

(Formation of coating layer)
Next, a coating layer was formed on the light scattering layer.

  The coating layer was formed on the light scattering layer by the following method.

  First, a mixture of titanate tetranormal butoxide and 3-glycidyloxypropyltrimethoxysilane in a ratio of 40:60 (volume ratio) is diluted with a solvent (1-butanol) and has a viscosity suitable for coating. A liquid for forming a coating layer was obtained. The coating layer forming liquid was dropped on the light scattering layer formed on the glass substrate, and a coating film was formed using a spin coater.

  The coating film was put into a drier maintained at 120 ° C. and held for 10 minutes to obtain a dry film having a dry film thickness of 0.6 μm.

  The dried film was baked by holding at 475 ° C. for 1 hour, thereby obtaining a baked film of 150 nm.

  Again, a coating layer-forming liquid was applied onto the fired film, dried, fired, and laminated to obtain a coating layer (first portion) formed of a 300 nm fired film.

Next, a SiO ₂ film was formed on the coating layer (first portion) by reactive sputtering.

An SiO ₂ target (4 inches φ, manufactured by Asahi Glass Co., Ltd.) was used as the target, and an RF power source (JRF-750: manufactured by JEOL Ltd.) was used as the sputtering power source. The ultimate vacuum in the chamber was 4 × 10 ⁻⁴ Pa, and a mixed gas of Ar and oxygen was supplied into the chamber. The flow rate of Ar gas was 50 sccm, and the flow rate of oxygen gas was 50 sccm. The total pressure was 0.3 Pa and the applied power was 300 W. The substrate heating temperature was set to 500 ° C.

The thickness of the SiO ₂ film obtained after the film formation was about 30 nm.

Thus, a first part consisting of TiO ₂ and SiO _2, and the coating layer having a second portion made of SiO ₂ was obtained.

(Formation of electrode layer)
Next, an electrode layer was formed on the coating layer.

  The electrode layer was formed on the coating layer by reactive sputtering.

An ITO target (4 inch φ, 17 wt% SnO ₂ -83 wt% In ₂ O ₃ , manufactured by Sumitomo Metal Mining Co., Ltd.) was used as the target. A DC power source (MDX: manufactured by Advanced Energy) and a pulsed power source (Sparkle-V: manufactured by Advanced Energy) were connected to the sputtering power source.

The ultimate vacuum in the chamber was 4 × 10 ⁻⁴ Pa, and a mixed gas of Ar and oxygen was supplied into the chamber. The flow rate of Ar gas was 50 sccm, and the flow rate of oxygen gas was 1 sccm. The total pressure was 0.3 Pa and the applied power was 200 W. The substrate heating temperature was set to 500 ° C.

  The thickness of the ITO electrode layer obtained after the film formation was about 150 nm.

  Through the above steps, a first light-transmitting substrate was manufactured.

  In addition, as a result of visual observation, coloring was not recognized by the 1st translucent board | substrate.

(Second translucent substrate)
A second light-transmitting substrate was manufactured in the same manner as the first light-transmitting substrate described above. However, when the second translucent substrate was manufactured, the second portion of the coating layer was a SiSnO film.

  This SiSnO film was formed on the first portion of the coating layer by reactive sputtering.

A SiSn target (35 at% Si-65 at% Sn, 70 mm × 200 mm) is used as the target, and a DC power supply (MDX: manufactured by Advanced Energy) and a pulsed power supply (Sparkle-V: manufactured by Advanced Energy) are used as the sputtering power supply. ) And used. The ultimate vacuum in the chamber was 4 × 10 ⁻⁴ Pa, and a mixed gas of Ar and oxygen was supplied into the chamber. The flow rate of Ar gas was 30 sccm, and the flow rate of oxygen gas was 20 sccm. The total pressure was 0.3 Pa and the applied power was 500 W. No substrate heating was performed.

  The thickness of the SiSnO film obtained after the film formation was about 100 nm.

Thus, a first part consisting of TiO ₂ and SiO _2, and the coating layer having a second portion consisting of SiSnO was obtained.

  After that, an electrode layer was formed by the same method as that for the first light-transmitting substrate described above to produce a second light-transmitting substrate.

  In addition, as a result of visual observation, coloring was not recognized by the obtained 2nd translucent board | substrate.

(Third translucent substrate)
A third light-transmitting substrate was manufactured by the same method as that for the first light-transmitting substrate. However, when the third light-transmitting substrate was produced, the second portion of the coating layer was not formed, and the electrode layer was directly formed on the first portion of the coating layer. The method for forming the electrode layer is the same as that for the above-described translucent substrate.

  As a result of visual observation, brown coloration was observed on the third translucent substrate.

(Fourth translucent substrate)
A fourth light-transmitting substrate was manufactured by the same method as that for the first light-transmitting substrate described above. However, when the fourth translucent substrate was produced, the second portion of the coating layer was not formed, and the electrode layer was formed directly on the first portion of the coating layer.

  The electrode layer was formed on the coating layer by reactive sputtering under the following conditions.

An ITO target (4 inch φ, 17 wt% SnO ₂ -83 wt% In ₂ O ₃ , manufactured by Sumitomo Metal Mining Co., Ltd.) was used as the target. A DC power source (MDX: manufactured by Advanced Energy) and a pulsed power source (Sparkle-V: manufactured by Advanced Energy) were connected to the sputtering power source.

The ultimate vacuum in the chamber was 4 × 10 ⁻⁴ Pa, and a mixed gas of Ar and oxygen was supplied into the chamber. The flow rate of Ar gas was 50 sccm, and the flow rate of oxygen gas was 5 sccm. The total pressure was 0.3 Pa and the applied power was 200 W. The substrate heating temperature was set to 500 ° C.

  The thickness of the ITO electrode layer obtained after the film formation was about 150 nm.

  Through the above steps, a fourth light-transmitting substrate was manufactured.

  In addition, as a result of visual observation, coloring was not recognized by the obtained 4th translucent board | substrate.

(Fifth translucent substrate)
A fifth light-transmitting substrate was produced in the same manner as the above-described fourth light-transmitting substrate. However, in this fifth translucent substrate, the flow rate of oxygen gas during the formation of the ITO electrode layer was 4 sccm. Other conditions are the same as those of the fourth light-transmitting substrate.

  Through the above steps, a fifth light-transmitting substrate was produced.

  In addition, as a result of visual observation, coloring was not recognized by the obtained 5th translucent board | substrate.

(Sixth translucent substrate)
A sixth light-transmitting substrate was manufactured by the same method as that for the above-described fourth light-transmitting substrate. However, in this sixth light-transmitting substrate, the flow rate of the oxygen gas when forming the ITO electrode layer was 3 sccm. Other conditions are the same as those of the sixth light-transmitting substrate.

  Through the above steps, a sixth light-transmitting substrate was produced.

  In addition, as a result of visual observation, coloring was not recognized by the obtained 6th translucent board | substrate.

(Seventh translucent substrate)
A seventh light-transmitting substrate was manufactured in the same manner as the above-described fourth light-transmitting substrate. However, in this seventh light-transmitting substrate, the flow rate of the oxygen gas when forming the ITO electrode layer was 2 sccm. Other conditions are the same as those of the seventh light-transmitting substrate.

  Through the above steps, a seventh light-transmitting substrate was manufactured.

  As a result of visual observation, brown coloration was observed on the seventh translucent substrate.

(Evaluation of absorption rate)
Next, the absorptance was evaluated using the various translucent substrates produced by the method described above.

  The absorptivity was evaluated by irradiating light from the glass substrate side of the translucent substrate. More specifically, of the incident light incident from the glass substrate side of the translucent substrate, the intensity of light reflected by the translucent substrate and the intensity of light transmitted through the translucent substrate are respectively measured. By subtracting these from the intensity of incident light, the absorptance of the translucent substrate was calculated.

  In FIG. 5, the measurement result of the absorptance obtained in the 1st translucent board | substrate-the 3rd translucent board | substrate is shown collectively.

  As shown in FIG. 5, it can be seen that the first light-transmitting substrate and the second light-transmitting substrate tend to have a significantly lower absorption rate than the third light-transmitting substrate.

  For example, at a wavelength of 450 nm, the absorptance of the third translucent substrate is 31.6%, whereas the absorptances of the first translucent substrate and the second translucent substrate are respectively 18.0% and 17.1%, which are significantly lower. Similarly, at a wavelength of 550 nm, the absorptance of the third translucent substrate is 23.9%, whereas the absorptivity of the first translucent substrate and the second translucent substrate is They were 14.3% and 14.1%, respectively. Furthermore, at a wavelength of 650 nm, the absorptance of the third translucent substrate is 23.6%, whereas the absorptance of the first translucent substrate and the second translucent substrate is respectively , 16.3% and 18.2%.

  In this way, by forming a coating layer in which the difference between the degree of oxidation at the interface with the electrode layer and the degree of internal oxidation is small, the influence of coloring of the coating layer is significantly suppressed, and light absorption is significantly suppressed. It was confirmed that

  FIG. 3 described above collectively shows the measurement results of the absorptance obtained in the fourth to seventh translucent substrates.

  As shown in FIG. 3, it can be seen that the fourth translucent substrate to the sixth translucent substrate tend to have a significantly lower absorption rate than the seventh translucent substrate.

  For example, at a wavelength of 450 nm, the absorptance of the seventh translucent substrate is 18.6%, whereas the absorptivity of the fourth translucent substrate to the sixth translucent substrate is respectively 12.7%, 13.3% and 14.75%, which are significantly lower. Similarly, at a wavelength of 550 nm, the absorptance of the seventh translucent substrate is 14.9%, whereas the absorptivity of the fourth translucent substrate to the sixth translucent substrate is They were 9.1%, 10.5%, and 12.3%, respectively. Furthermore, at a wavelength of 650 nm, the absorptance of the seventh light transmitting substrate is 17.6%, whereas the absorptances of the fourth light transmitting substrate to the sixth light transmitting substrate are respectively 10.8%, 11.9% and 13.4%.

  In this way, by forming a coating layer in which the difference between the degree of oxidation at the interface with the electrode layer and the degree of internal oxidation is small, the influence of coloring of the coating layer is significantly suppressed, and light absorption is significantly suppressed. It was confirmed that

  The present invention can be applied to organic LED elements used in light emitting devices and the like.

DESCRIPTION OF SYMBOLS 20 Light scattering layer 30 Covering layer 40 1st electrode layer 80 Alteration layer 90 Interface 100 Organic LED element by this invention 110 Transparent substrate 120 Light scattering layer 121 Base material 124 Scattering substance 130 Covering layer 140 1st electrode (anode) layer 150 Organic Light-Emitting Layer 160 Second Electrode (Cathode) Layer 170 Light Extraction Surface

Claims (11)

A transparent substrate, a light scattering layer formed on the transparent substrate, a transparent first electrode layer formed on the light scattering layer, and an organic light emitting layer formed on the first electrode layer An organic LED element having a second electrode layer formed on the organic light emitting layer,
The light scattering layer has a base material made of glass, and a plurality of scattering materials dispersed in the base material,
Between the light scattering layer and the first electrode layer, a coating layer containing a metal oxide and / or metal oxynitride is installed,
The organic LED element, wherein the coating layer has a small difference between the degree of oxidation at the interface with the first electrode layer and the degree of internal oxidation.   The organic LED element according to claim 1, wherein the coating layer includes at least one metal element selected from the group consisting of titanium, indium, tin, tungsten, tantalum, and niobium.   The organic LED element according to claim 1, wherein the coating layer contains titanium oxide and silicon oxide.   The organic LED element according to any one of claims 1 to 3, wherein the scattering material is bubbles and / or precipitated crystals of glass constituting the base material and / or a refractory filler. A translucent substrate having a transparent substrate, a light scattering layer formed on the transparent substrate, and an electrode layer formed on the light scattering layer,
The light scattering layer has a base material made of glass, and a plurality of scattering materials dispersed in the base material,
Between the light scattering layer and the electrode layer, a coating layer containing a metal oxide and / or metal oxynitride is installed,
The translucent substrate is characterized in that the coating layer has a small difference between the degree of oxidation at the interface with the electrode layer and the degree of internal oxidation. A method for producing a transparent substrate having a transparent substrate, a light scattering layer, and an electrode layer,
(A) forming a light scattering layer on the transparent substrate,
The light scattering layer includes a base material made of glass, and a plurality of scattering materials dispersed in the base material;
(B) installing a coating layer containing a metal oxide and / or a metal oxynitride on the light scattering layer;
(C) placing an electrode layer on the coating layer;
Have
After the step (c), the coating layer has a small difference between the degree of oxidation at the interface with the electrode layer and the degree of internal oxidation. The step (b)
(B1) placing an organometallic solution and / or a sol-gel solution of organometallic particles on the light scattering layer;
(B2) heat-treating the sol-gel solution to form the coating layer;
The method of claim 6, comprising:   The step (b) is such that the degree of oxidation of the metal oxide or metal oxynitride on the outermost surface side of the coating layer is greater than the degree of oxidation of the internal metal oxide or metal oxynitride, The method according to claim 6, further comprising the step of forming the covering layer.   In the step (c), after the step (c), the electrode layer is formed under such a condition that the difference between the degree of oxidation at the interface with the electrode layer and the degree of internal oxidation is reduced in the coating layer. The method according to claim 6, further comprising the step of:   The said coating layer contains at least 1 metal element selected from the group which consists of titanium, indium, tin, tungsten, tantalum, and niobium, The one of Claim 6 thru | or 9 characterized by the above-mentioned. Method.   The method according to claim 6, wherein the covering layer includes titanium oxide and silicon oxide.

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