JPWO2015141397A1 - Organic electroluminescence device and method for manufacturing the same - Google Patents

Abstract

The subject of this invention is providing the organic EL element with few disconnections of the conducting wire part which connects the electrode layer and lead wiring of a transparent electrode, and its manufacturing method. The present invention is an organic electroluminescence device comprising a pair of electrodes and a light emitting layer on a substrate, the transparent electrode disposed on the substrate side, the light scattering layer between the substrate and the transparent electrode, and the transparent electrode The transparent electrode is made of a base layer containing a compound containing a nitrogen atom or a sulfur atom, and silver or a silver alloy or copper or a copper alloy is used on the base layer. An electrode layer formed so that the electrode layer overlaps a region of the light emitting layer, and a lead wire portion exposed from the main body portion to the lead-out wiring side. The wiring is formed so as to overlap at least a part of the conductive wire portion, and the base layer is formed below both the main body portion and the conductive wire portion of the electrode layer.

Description

  The present invention relates to an organic electroluminescence element and a method for manufacturing the same. Specifically, the present invention relates to an organic electroluminescence element in which a conductor portion connecting an electrode layer of a transparent electrode and a lead wiring is less disconnected, and a method for manufacturing the same.

  BACKGROUND ART An organic electroluminescence (EL) element generally includes a light emitting layer containing a light emitting organic compound and a pair of electrodes that sandwich the light emitting layer. When a voltage is applied to the pair of electrodes to inject holes and electrons into the light emitting layer, excitons (exingtons) are generated by recombination of the holes and electrons. When the exciton is deactivated, light is emitted from the light emitting layer, and the organic EL element emits light.

In the organic EL element, in order to extract light emitted from the light emitting layer to the outside, a transparent electrode is used as an electrode disposed on the light extraction side of the pair of electrodes.
As the transparent electrode, indium tin oxide (ITO) is widely known, but as a new transparent electrode replacing this ITO, a transparent electrode using silver or a silver alloy has been proposed (for example, Patent Document 1). Silver is cheaper than ITO, and can obtain high conductivity and light transmittance equivalent to those of ITO.

  The transparent electrode is connected to the lead-out wiring, and is connected to an external power source through the lead-out wiring. Therefore, the electrode layer of the transparent electrode includes a main body portion of the electrode layer formed so as to overlap with the region of the light emitting layer, and a conductive wire portion for connection to the lead-out wiring, and the conductive wire portion is exposed from the main body portion. Is formed.

However, the electrode layer of silver or silver alloy is formed as a thin film having a thickness of, for example, 10 nm or less in order to improve light transmittance. Since it is a thin film, continuous film formability may be reduced due to irregularities on the surface below the electrode layer, and the conducting wire portion of the electrode layer may be disconnected. In particular, a light scattering layer may be provided below the electrode layer in order to increase the light extraction efficiency of the organic EL element. However, since the light scattering layer has a large surface irregularity, the conductor portion of the electrode layer may be disconnected. There were many.
In addition, when a highly flexible film is used as the substrate, there is a problem that if the continuous film formability of the conductive wire portion of the electrode layer is low, the substrate is likely to be disconnected due to a load during bending.

International publication 2013/073356 pamphlet

  The present invention has been made in view of the above problems and circumstances, and an object of the present invention is to provide an organic electroluminescence element in which there is little disconnection of a conductive wire portion connecting an electrode layer of a transparent electrode and a lead-out wiring, and a manufacturing method thereof.

In the process of studying the cause of the above-mentioned problems in order to solve the above-mentioned problems, the electrode layer of the transparent electrode formed using silver, copper, or an alloy thereof is a thin film. It has been found that the continuous film formability of the conductive wire portion of the electrode layer formed for connection to is obstructed by the irregularities on the surface below the electrode layer, and is easily broken. In particular, when there is a light scattering layer below the electrode layer, the surface of the light scattering layer has large irregularities, so that it was easy to break. The inventors of the present invention have considered that the wire breakage can be reduced by reducing the unevenness of the surface of the lower layer not only in the main body portion of the electrode layer but also in the lead wire portion, and improving the continuous film forming property in the lead wire portion.
That is, the subject concerning this invention is solved by the following means.

1. An organic electroluminescence device comprising a pair of electrodes on a substrate and a light emitting layer disposed between the pair of electrodes,
Of the pair of electrodes, a transparent electrode disposed on the substrate side;
A light scattering layer located between the substrate and the transparent electrode;
A lead wiring for connecting the transparent electrode to an external power source,
The transparent electrode comprises an underlayer containing a compound containing a nitrogen atom or a sulfur atom, and an electrode layer formed on the underlayer using silver or a silver alloy, or copper or a copper alloy,
The electrode layer includes a main body portion formed so as to overlap a region of the light emitting layer, and a conductive wire portion exposed from the main body portion to the lead-out wiring side,
The lead-out wiring is formed so as to overlap at least a part of the conductor portion;
The organic electroluminescence element, wherein the underlayer is formed under both the main body portion and the conductor portion of the electrode layer.

2. Further comprising a smooth layer positioned between the light scattering layer and the underlayer,
The smoothing layer is formed such that one end of the smoothing layer on the lead-out wiring side is positioned closer to the lead-out wiring side than one end of the light scattering layer on the lead-out wiring side. The organic electroluminescent element of the item.

  3. 3. The organic electroluminescence device according to claim 2, wherein the smooth layer is formed under both the main body portion and the conductor portion of the electrode layer.

  4). 4. The organic electroluminescence device according to claim 3, wherein the light scattering layer is formed below both the main body portion and the conductor portion of the electrode layer.

5. A method for producing an organic electroluminescent device comprising a transparent electrode provided with an electrode layer on a substrate, an electrode paired with the transparent electrode, and a light emitting layer disposed between the pair of electrodes,
(A) forming a light scattering layer on the substrate;
(B) forming an underlayer of the electrode layer on the light scattering layer, the underlayer containing a compound containing a nitrogen atom or a sulfur atom;
(C) On the underlayer, using silver or a silver alloy, or copper or a copper alloy, a main body portion of the electrode layer is formed so as to overlap with the region of the light emitting layer, and exposed from the main body portion. Forming a conductive wire portion of the electrode layer;
(D) forming a lead-out line for connecting the transparent electrode to an external power source so as to overlap at least a part of the conductor portion;
In the step (b), the base layer is formed in both the region where the main body portion of the electrode layer is formed and the region where the conductive wire portion is formed.

6). (E) further comprising a step of forming a smooth layer between the light scattering layer and the underlayer;
In the step (e), the smoothing layer is formed such that one end of the smoothing layer on the lead-out wiring side is positioned closer to the lead-out wiring side than one end of the light scattering layer on the lead-out wiring side. 6. The method for producing an organic electroluminescence element according to item 5, wherein

  7). In the step (e), the smoothing layer is formed in both the region where the main body portion of the electrode layer is formed and the region where the conductive wire portion is formed. Manufacturing method of luminescence element.

  8). In the step (a), the light scattering layer is formed in either the region where the main body portion of the electrode layer is formed or the region where the conductive wire portion is formed. Manufacturing method of electroluminescent element.

  By the above means of the present invention, it is possible to provide an organic electroluminescence element in which there is little disconnection of the conductive wire portion connecting the electrode layer of the transparent electrode and the lead-out wiring, and a manufacturing method thereof.

The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.
According to the present invention, the base layer is formed not only in the main body portion of the electrode layer but also under the conductor portion. Even if there is a light scattering layer having a large surface irregularity below the electrode layer, the irregularity is reduced by the underlying layer, so that the continuous film-forming property can be improved even in the conductor portion of the electrode layer. Therefore, the disconnection of the conducting wire portion due to the deterioration of the continuous film formability can be reduced.

Sectional drawing which shows the structure of the organic electroluminescent element which concerns on this Embodiment Sectional drawing which shows the detail from the board | substrate of FIG. 1 to a light emitting layer 2A top view Sectional drawing which shows a structure in case one end of a smooth layer is located in the extraction wiring side rather than one end of a light-scattering layer Sectional drawing which shows the structure from a board | substrate to a light emitting layer in case a smooth layer is formed under the main-body part and conducting-wire part of an electrode layer. Sectional drawing which shows the structure from a board | substrate to a light emitting layer when a light-scattering layer is formed under the main-body part and conducting-wire part of an electrode layer It is a top view which shows the area | region in which each layer of an organic EL element is formed in an Example.

The present invention is an organic electroluminescent device comprising a pair of electrodes and a light emitting layer disposed between the pair of electrodes on a substrate, and is disposed on the substrate side of the pair of electrodes. A compound comprising: a transparent electrode; a light scattering layer positioned between the substrate and the transparent electrode; and a lead-out wiring connecting the transparent electrode to an external power source, wherein the transparent electrode contains a nitrogen atom or a sulfur atom. And an electrode layer formed using silver or a silver alloy, or copper or a copper alloy on the underlayer, and the electrode layer overlaps a region of the light emitting layer. A main body portion formed, and a lead wire portion exposed from the main body portion to the lead wire side, wherein the lead wire is formed so as to overlap at least a part of the lead wire portion, and the base layer is The electrode layer And characterized in that it is formed in the bottom of any body portion and lead portions.
This feature is a technical feature common to the inventions according to claims 1 to 8.

  As an embodiment of the present invention, from the viewpoint of further reducing the disconnection of the conductive wire portion, it further comprises a smooth layer positioned between the light scattering layer and the base layer, and one end of the smooth layer on the lead-out wiring side is It is preferable that the smoothing layer is formed so as to be positioned closer to the lead-out wiring side than one end of the light scattering layer on the lead-out wiring side.

  From the viewpoint of reducing the step between the main body portion and the conductor portion of the electrode layer and reducing the disconnection caused by the step, the smooth layer is formed below both the main body portion and the conductor portion of the electrode layer. It is preferable that the light scattering layer is further formed under both the main body portion and the conductor portion of the electrode layer.

The manufacturing method of the organic electroluminescence element of the present invention includes a transparent electrode including an electrode layer, an electrode paired with the transparent electrode, and a light emitting layer disposed between the pair of electrodes on a substrate. A method for producing an organic electroluminescence device, comprising: (a) a step of forming a light scattering layer on the substrate; and (b) an underlayer of the electrode layer on the light scattering layer, wherein the nitrogen atom or Forming a base layer containing a compound containing a sulfur atom; and (c) using silver or a silver alloy or copper or a copper alloy on the base layer so as to overlap the region of the light emitting layer. Forming a main body portion of the electrode layer and forming a conductive wire portion of the electrode layer exposed from the main body portion; and (d) a lead wiring for connecting the transparent electrode to an external power source, Forming at least a part thereof, and in the step (b), the base layer is formed in both the region where the main body portion of the electrode layer is formed and the region where the conductor portion is formed. It is characterized by forming.
Since the preferable aspect of the manufacturing method of this invention is the same as the preferable aspect of the organic electroluminescent element mentioned above, description is abbreviate | omitted.

Hereinafter, the present invention, its components, and modes for carrying out the present invention will be described in detail.
In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

[Organic electroluminescence device]
FIG. 1 is a cross-sectional view showing a configuration of an organic electroluminescence (hereinafter abbreviated as EL) element 10 according to an embodiment of the present invention.
As shown in FIG. 1, the organic EL element 10 includes a pair of electrodes E1 and E2 and an organic functional layer 3 disposed between the pair of electrodes E1 and E2 on a substrate 1.
The organic functional layer 3 is a light emitting unit in which a hole injection layer 3a, a hole transport layer 3b, a light emitting layer 3c, an electron transport layer 3d, and an electron injection layer 3e are laminated in this order. The organic EL element 10 is configured to extract light h emitted from the light emitting layer 3c of the organic functional layer 3 from at least the substrate 1 side. The region of the light emitting layer 3c that overlaps the pair of electrodes E1 and E2 is referred to as a light emitting region, and light emission occurs in this light emitting region.

Of the pair of electrodes E1 and E2, the electrode E1 is a transparent electrode disposed on the substrate 1 side that extracts light from the light emitting layer 3c. Hereinafter, the electrode E1 is referred to as a transparent electrode E1. The organic EL element 10 includes a lead-out wiring 5 that connects the transparent electrode E1 to an external power source.
In addition, in the organic EL element 10, although the transparent electrode E1 is an anode and the electrode E2 is a cathode, each polarity may be reverse. When the polarity is reversed, the arrangement order of the layers of the organic functional layer 3 is also reversed.

The organic EL element 10 includes an internal light extraction layer 2A between the substrate 1 and the transparent electrode E1 in order to increase the light extraction efficiency. The internal light extraction layer 2A includes at least a light scattering layer.
In order to further improve the light extraction efficiency, the organic EL element 10 can include an external light extraction layer 2B on the surface of the substrate 1 opposite to the surface on which the internal light extraction layer 2A is formed.
Further, the organic EL element 10 includes a sealing material 6 that covers each layer on the substrate 1 in order to prevent deterioration of each layer on the substrate 1. The sealing material 6 is bonded to the electrode E2 and the lead-out wiring 5 with an adhesive 7.

2A is a cross-sectional view showing details of each layer from the substrate 1 to the light emitting layer 3c, and FIG. 2B is a top view of FIG. 2A. The AA line in FIG. 2B shows the cross-sectional line of sectional drawing of FIG. 2A.
As shown in FIG. 2A, a light scattering layer 21 and a smooth layer 22 are formed on the substrate 1 as an internal light extraction layer 2A so as to overlap the region of the light emitting layer 3c. The smooth layer 22 is disposed between the light scattering layer 21 and the base layer Eb in order to smooth the unevenness on the surface of the light scattering layer 21.

  On the smooth layer 22, an underlayer Eb containing a compound containing a nitrogen atom or a sulfur atom, and an electrode layer Ea formed on the underlayer Eb using silver or a silver alloy, or copper or a copper alloy, The transparent electrode E1 provided with is formed. Since the compound contained in the base layer Eb suppresses aggregation of silver or copper, the electrode layer Ea can be formed as a thin film, and the transparent electrode E1 having high light transmittance can be obtained.

As shown in FIGS. 2A and 2B, the electrode layer Ea includes a main body part a1 formed so as to overlap the region of the light emitting layer 3c, and a conductive wire part a2 exposed from the main body part a1 to the lead-out wiring 5 side. .
As long as the main body portion a1 is formed so as to overlap the region of the light emitting layer 3c, it may be formed at the same position as the region of the light emitting layer 3c and with the same area, so as to include the region of the light emitting layer 3c. It may be formed with a larger area than the light emitting layer 3c.
The lead wire portion a2 is a part of the electrode layer Ea formed for connection to the lead wire 5, and the lead wire 5 is formed so as to overlap at least a part of the lead wire portion a2.

The underlayer Eb is formed below both the main body portion a1 and the conductor portion a2 of the electrode layer Ea.
Thereby, even when the material of the light scattering layer 21 flows out when the light scattering layer 21 is formed and fine unevenness is generated on the lead wiring 5 side from the main body portion a1 of the electrode layer Ea as shown in FIG. 2A. The unevenness on the surface of the light scattering layer 21 located under the conductor portion a2 of the electrode layer Ea can be reduced by the base layer Eb. It is possible to prevent the continuous film formability of the conductor portion a2 formed as a thin film from being deteriorated due to the unevenness, and to reduce the disconnection of the conductor portion a2. Moreover, since the base layer Eb improves the continuous film-forming property of the conductor part a2 by interaction with silver or copper in the electrode layer Ea, the disconnection of the conductor part a2 can be effectively reduced.

  In the organic EL element 10, the base layer Eb may be formed so as to also serve as the smooth layer 22.

[Modification 1]
In the organic EL element 10, as shown in FIG. 3, one end 22p of the smoothing layer 22 on the lead-out wiring 5 side is positioned closer to the lead-out wiring 5 side than one end 21p of the light scattering layer 21 on the lead-out wiring 5 side. The smooth layer 22 is preferably formed.
As a result, the smooth layer 22 can be formed so as to cover the light scattering layer 21 at least on the lead-out wiring 5 side, and the unevenness of the light scattering layer 21 that affects the continuous film formability of the conductive wire portion a2 of the electrode layer Ea. The impact can be greatly reduced.

[Modification 2]
In the organic EL element 10, as shown in FIG. 4, it is preferable that the smooth layer 22 is formed below both the main body portion a1 and the conductor portion a2 of the electrode layer Ea.
Since the unevenness on the surface of the light scattering layer 21 is smoothed by the smooth layer 22, the continuous film-forming property of the electrode layer Ea can be further improved, and disconnection can be more effectively prevented. Further, since the smooth layer 22 is also provided under the conductor portion a2 in the same manner as the main body portion a1, the step between the main body portion a1 and the conductor portion a2 is reduced, and thus the film formability of the electrode layer Ea on the step portion ( Step coverage) is improved, and disconnection due to a step can be reduced.

[Modification 3]
In the organic EL element 10, as shown in FIG. 5, it is preferable that the light scattering layer 21 is formed below both the main body portion a1 and the conductive wire portion a2 of the electrode layer Ea.
Thereby, since the level | step difference of the main-body part a1 of the electrode layer Ea and the conducting wire part a2 becomes still smaller, or a level | step difference is lose | eliminated, the disconnection resulting from a level | step difference can further be reduced.

Hereinafter, details of each layer of the organic EL element 10 will be described.
〔substrate〕
The substrate 1 has high transparency when extracting light from the substrate 1 side.
Specifically, the light transmittance of the substrate 1 is preferably 70% or more, more preferably 80% or more, still more preferably 90% or more, and particularly preferably 95% or more. Here, the light transmittance is the total light transmittance, and can be measured according to JIS K 7375: 2008 “Plastics—How to obtain total light transmittance and total light reflectance”.
The substrate 1 preferably has flexibility in order to impart flexibility to the organic EL element 10.

Preferable substrate 1 includes film-like or plate-like glass, resin film, and the like.
Examples of the glass include silica glass, soda lime silica glass, lead glass, borosilicate glass, and alkali-free glass.
When glass is used as the substrate 1, physical treatment such as polishing is performed on the surface of the substrate 1 as necessary from the viewpoint of enhancing adhesion, durability, smoothness, and gas barrier properties with the internal light extraction layer 2 </ b> A. Or a film made of an inorganic compound or an organic compound, or a hybrid film obtained by combining these films.

  Examples of the resin film material include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, and cellulose acetate propionate. (CAP), cellulose esters such as cellulose acetate phthalate and cellulose nitrate and derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, Polyimide, polyethersulfone (PES), polyphenylene sulfide, polysulfone , Polyether imide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic and polyarylates, Arton (trade name, manufactured by JSR), Appel (trade name, manufactured by Mitsui Chemicals), etc. Examples thereof include resins.

When the substrate 1 is a resin film, it is preferable to provide a gas barrier layer on the substrate 1 in order to shield intrusion of gas such as water and oxygen in the atmosphere.
The gas barrier layer has a water vapor permeability (temperature 25 ± 0.5 ° C., relative humidity 90 ± 2% RH) measured by a method according to JIS-K-7129-1992 of 0.01 g / (m ² · 24. It is preferable that the gas barrier property is as follows: the water vapor permeability is 0.00001 g / (m ² · 24 hours) or less, and the oxygen permeability measured in accordance with JIS-K-7126-1987 is It is more preferable to show a high gas barrier property of 0.001 g / (m ² · 24 hours) or less.

The material of the gas barrier layer may be any material that can suppress the ingress of gas such as water and oxygen, and examples thereof include inorganic compounds such as silicon oxide, silicon dioxide, and silicon nitride.
The gas barrier layer preferably has a multilayer structure in which a layer made of an inorganic compound and a layer made of an organic compound are laminated from the viewpoint of obtaining high gas barrier properties.

A compound that can form a metal oxide, a metal nitride, or a metal oxynitride by ultraviolet irradiation under a specific atmosphere can also be suitably used. Of these, compounds that can be modified at a relatively low temperature described in JP-A-8-112879 are preferred.
Specifically, polysiloxane (including polysilsesquioxane) having Si—O—Si bond, polysilazane having Si—N—Si bond, both Si—O—Si bond and Si—N—Si bond And polysiloxazan containing These are ceramicized at a low temperature by irradiation with ultraviolet rays, excimer light or the like. Two or more of these can be mixed and used, or can be sequentially laminated in different types or simultaneously laminated.

When the substrate 1 is a resin film, a bleed-out prevention layer can be provided on the substrate 1 in order to suppress a bleed-out phenomenon in which unreacted oligomers and the like in the substrate 1 migrate to the surface of the substrate 1 and precipitate.
In addition, a planarization layer can be provided in order to planarize the unevenness of the surface of the substrate 1.
As the bleed-out prevention layer and the planarization layer, a known resin can be used. For example, a resin that is cured by active rays such as ultraviolet rays and electron beams can be used.

  The thickness of the substrate 1 is preferably in the range of 10 to 500 μm, more preferably in the range of 20 to 250 μm, and still more preferably in the range of 30 to 150 μm. If the thickness of the substrate 1 is in the range of 10 to 500 μm, a stable gas barrier property can be obtained, which is suitable for roll-to-roll system conveyance.

(Light extraction layer)
The internal light extraction layer 2A and the external light extraction layer 2B are provided in order to improve the light extraction efficiency and increase the external quantum efficiency.
As described above, the internal light extraction layer 2 </ b> A can include at least the light scattering layer 21, and can further include the smoothing layer 22 on the light scattering layer 21.

  The internal light extraction layer 2A preferably has a light transmittance of 50% or more, more preferably 55% or more, and still more preferably 60% or more.

(Light scattering layer)
The light scattering layer 21 is preferably a high refractive index layer having a refractive index measured at a light wavelength of 550 nm in a range of 1.7 or more and less than 2.5. The refractive index can be measured with a multiwavelength Abbe refractometer, a prism camera, a Mickelson interferometer, a spectroscopic ellipsometer, or the like.
The light scattering layer 21 may be composed of a single material having such a high refractive index, or a mixture of two or more materials may have a high refractive index. When two or more kinds of materials are mixed, the refractive index of the light scattering layer 21 is a calculated refractive index calculated by a total value obtained by multiplying the refractive index specific to each material by the mixing ratio. As long as the light scattering layer 21 as a whole satisfies the range of 1.7 or more and less than 2.5, the refractive index of each material may be outside this range.

  The light scattering layer 21 in the case of mixing two or more kinds of materials contains light scattering particles having a higher refractive index than that of the layer medium, using a binder as a layer medium, and scatters incident light by utilizing the difference in the respective refractive indexes. It is preferable to make it.

Examples of the binder include polyacrylic acid ester, polymethacrylic acid ester, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), Known resins such as polystyrene (PS) and nylon (Ny) can be used without particular limitation.
As the binder, a hydrophilic resin, a curable resin, the above-described polysiloxane (including polysilsesquioxane), polysilazane, polysiloxazan, or the like can also be used.

The light scattering particles are preferably transparent particles having a particle size equal to or larger than the region that causes Mie scattering in the visible light region, and the average particle size is 0.2 μm or more. The upper limit of the average particle size is preferably less than 1 μm. If the particle size is less than 1 μm, it is not necessary to increase the thickness of the smooth layer 22 in order to smooth the surface of the light scattering layer 21 containing light scattering particles.
The average particle diameter of the light scattering particles can be measured by subjecting a cross-sectional image with a transmission electron microscope (TEM) to image processing.

  There is no restriction | limiting in particular as light-scattering particle | grains, According to the objective, it can select suitably, Organic fine particles or inorganic fine particles may be sufficient. Among these, inorganic fine particles having a high refractive index are preferable.

  Examples of organic fine particles having a high refractive index include polymethyl methacrylate beads, acrylic-styrene copolymer beads, melamine beads, polycarbonate beads, styrene beads, crosslinked polystyrene beads, polyvinyl chloride beads, benzoguanamine-melamine formaldehyde beads, and the like. It is done.

Examples of the inorganic fine particles having a high refractive index include inorganic oxide particles made of at least one oxide selected from zirconium, titanium, indium, zinc, antimony, cerium, niobium and tungsten. _{Specifically, ZrO 2, TiO 2, BaTiO} 3, In 2 O 3, ZnO, Sb 2 O 3, ITO, CeO 2, Nb 2 O 5, WO 3 and the like. Among these, TiO ₂ , BaTiO ₃ , ZrO ₂ , CeO ₂ or Nb ₂ O ₅ is preferable, and TiO ₂ is most preferable. TiO ₂ is preferable because the rutile type has lower catalytic activity than the anatase type, and the weather resistance and refractive index of the light scattering layer 21 or an adjacent layer are high.

  The average particle diameter of the light scattering particles is preferably about the same as the thickness of the light scattering layer 21 so as to be in contact with or close to the interface between the light scattering layer 21 and the smooth layer 22. Thereby, the evanescent light that permeates into the light scattering layer 21 when total reflection occurs in the smooth layer 22 can be scattered by the particles, and the light extraction efficiency is improved. On the contrary, when the layer thickness of the light scattering layer 21 exceeds the average particle diameter of the light scattering particles, for example, when the layer thickness of the light scattering layer 21 is 1.3 times the average particle diameter of the light scattering particles, the light scattering particles It exists at a position far from the interface, does not scatter evanescent light, and does not contribute to the improvement of light extraction efficiency. Moreover, it is preferable that the particle size distribution of the light scattering particles is small from the viewpoint of suppressing the uniformity of coating or interface smoothness, and the deterioration of display performance due to an increase in reflected scattered light.

  The content of the light scattering particles in the light scattering layer 21 is preferably in the range of 1 to 70% and more preferably in the range of 5 to 50% in terms of volume filling factor. Thereby, the density distribution of the refractive index distribution can be made dense at the interface between the light scattering layer 21 and the smooth layer 22, and the light extraction efficiency can be improved by increasing the amount of light scattering.

  When the light-scattering layer 21 contains light-scattering particles, the thickness of the light-scattering layer 21 is preferably in the range of 100 to 2000 nm from the viewpoint of efficiently extracting the light h by scattering the light h. The layer thickness of the light scattering layer 21 is an average layer thickness.

The light scattering layer 21 may be a high refractive index layer having a refractive index in a range of 1.7 or more and less than 2.5 by controlling the shape of the layer to an uneven structure that diffracts or diffuses light. .
The light scattering layer 21 having a concavo-convex structure for diffracting or diffusing light is entirely formed at the interface between the substrate 1 and the transparent electrode E1 (anode) if the internal light extraction layer 2A is not included in the light h emitted from the light emitting layer 3c. It is possible to extract part of the light that is reflected and cannot be extracted, and the light extraction efficiency can be improved.

The concavo-convex structure is a structure in which concave and convex portions are arranged at a constant pitch (period), and acts as a diffraction grating.
In order to improve the extraction efficiency of visible light, the diffraction grating needs to diffract light within a wavelength range of 400 to 750 nm in a visible light medium. There are certain relationships among the incident angle and the exit angle of light to the diffraction grating, the diffraction grating interval (arrangement period of the concave and convex portions), the wavelength of light, the refractive index of the medium, the diffraction order, and the like. In order to diffract visible light and light in the wavelength region in the vicinity thereof, the arrangement period of the concave and convex portions needs to have a constant value in the range of 150 to 3000 nm corresponding to the wavelength at which the light extraction efficiency is improved. There is.

  The concavo-convex structure acting as a diffraction grating is described in, for example, Japanese Patent Application Laid-Open Nos. 11-283951 and 2003-115377. The stripe-shaped diffraction grating does not have a diffraction effect in the direction parallel to the stripe, and therefore preferably functions as a diffraction grating uniformly from any direction two-dimensionally. For example, as a shape viewed from the normal line direction of the surface of the substrate 1, it is preferable that concave portions and convex portions having a predetermined shape are regularly formed at predetermined intervals.

  Even when the light scattering layer 21 has an uneven structure, the layer thickness of the light scattering layer 21 is preferably in the range of 100 to 2000 nm, as in the case of containing light scattering particles.

(Smooth layer)
The smooth layer 22 is provided on the light scattering layer 21 in order to smooth the irregularities on the surfaces of the substrate 1 and the light scattering layer 21.
The smooth layer 22 is preferably a high refractive index layer having a refractive index measured at a light wavelength of 550 nm within a range of 1.7 or more and less than 2.5 in order to improve light extraction efficiency. As long as the refractive index is in the range of 1.7 or more and less than 2.5, it may be composed of a single material or may be composed of two or more materials. Similar to the light scattering layer 21, the calculated refractive index is used as the refractive index of the smooth layer 22 in the case of being composed of two or more materials.

From the viewpoint of smoothing the surface of the internal light extraction layer 2A, the smooth layer 22 preferably has a smoothness with an arithmetic average roughness Ra (also referred to as average surface roughness Ra) of less than 100 nm. The arithmetic average roughness Ra of the surface is more preferably less than 30 nm, further preferably less than 10 nm, and particularly preferably less than 5 nm.
The arithmetic average roughness Ra can be measured according to JIS B0601-2001.

As with the light scattering layer 21, the smooth layer 22 preferably contains particles having a binder as a layer medium and a higher refractive index than the layer medium.
As the binder, the same binder as the light scattering layer 21 can be used.

The particles exhibiting a high refractive index are preferably fine particle sols, and particularly preferably metal oxide fine particle sols.
The refractive index of the metal oxide fine particles is preferably 1.7 or more in a bulk state, more preferably 1.85 or more, further preferably 2.0 or more, and 2.5 or more. It is particularly preferred. When the refractive index is 1.7 or more, the light extraction effect is improved.
The refractive index of the metal oxide fine particles is preferably 3.0 or less. When the refractive index is 3.0 or less, multiple scattering in the smooth layer 22 is reduced, and transparency is improved.

The particle size of the metal oxide fine particles is usually preferably 5 nm or more, more preferably 10 nm or more, and further preferably 15 nm or more. When the particle size is 5 nm or more, aggregation of the metal oxide fine particles is suppressed and transparency is improved. Further, when the particle size is large, the surface area is reduced, the catalytic activity is lowered, and the deterioration of the smooth layer 22 and its adjacent layers can be delayed.
On the other hand, the particle diameter of the metal oxide fine particles is preferably 70 nm or less, more preferably 60 nm or less, and further preferably 50 nm or less. When the particle size is 70 nm or less, the transparency of the smooth layer 22 is improved.
As long as the effects of the present invention are not impaired, the particle size distribution is not limited and may be wide or narrow and may have a plurality of distributions.

The content of the metal oxide fine particles in the smooth layer 22 is preferably 70% by mass or more, more preferably 80% by mass or more, and 85% by mass or more with respect to the mass of the entire smooth layer 22. More preferably. When the content is 70% by mass or more, it becomes substantially easy to set the refractive index of the smooth layer 22 to 1.80 or more.
On the other hand, the content of the metal oxide fine particles is preferably 97% by mass or less, and more preferably 95% by mass or less. When the content is 97% by mass or less, the smooth layer 22 can be easily applied, and the brittleness resistance and flex resistance of the smooth layer 22 after drying are improved.

The metal oxide fine particles are more preferably TiO ₂ (titanium dioxide) from the viewpoint of stability. Among them, the rutile type is preferable because it has lower catalytic activity than the anatase type, and thus the weather resistance of the smooth layer 22 and its adjacent layer is high and the refractive index is high.
As a method for preparing the titanium dioxide sol, reference can be made to, for example, JP-A-63-17221, JP-A-7-819, JP-A-9-165218, JP-A-11-43327, and the like.
Particularly preferred primary particle diameter of the titanium dioxide fine particles is in the range of 5 to 15 nm, most preferably in the range of 6 to 10 nm.

  The layer thickness of the smooth layer 22 may be selected so that the unevenness of the light scattering layer 21 can be smoothed, such as short-circuiting of the electrodes E1 and E2 due to the light scattering particles or unevenness of the light scattering layer 21, electric field concentration, etc. From the standpoint of preventing this, it is preferably in the range of 100 to 2000 nm.

The external light extraction layer 2B can be provided by bonding, for example, a microlens array sheet, a light diffusion film, or the like to the surface of the substrate 1 opposite to the surface on which the transparent electrode E1 is provided via an adhesive.
Specific products that can be used as the external light extraction layer 2B include a microlens array sheet manufactured by MNtech, a diffusion film manufactured by Kimoto, and the like.

[Transparent electrode]
As described above, the transparent electrode E1 includes the base layer Eb and the electrode layer Ea formed on the base layer Eb.
In consideration of light extraction, the transparent electrode E1 preferably has a light transmittance of 50% or more measured at a light wavelength of 550 nm.

(Underlayer)
The underlayer Eb contains a compound containing a nitrogen atom or a sulfur atom in order to suppress aggregation of silver or copper, which is the main component of the electrode layer Ea, when the electrode layer Ea is formed.
By providing the electrode layer Ea on such an underlayer Eb, each silver atom or each copper atom in the electrode layer Ea interacts with a compound containing a nitrogen atom or a sulfur atom in the underlayer Eb, and the underlayer Eb The distance between each silver atom or each copper atom diffusing on the surface is shortened, and aggregation of silver or copper is suppressed.

  The compound containing a nitrogen atom or a sulfur atom contained in the underlayer Eb may be an inorganic compound or an organic compound as long as it contains a nitrogen atom or a sulfur atom in the molecule. Specific examples of the compound include a compound containing a heterocyclic ring having a nitrogen atom as a hetero atom, an organic compound containing a sulfur atom, or a polymer. Especially, the compound containing the heterocyclic ring which uses a nitrogen atom as a hetero atom, or the compound containing a sulfur atom is preferable.

  Examples of the heterocyclic ring having a nitrogen atom as a hetero atom include, for example, aziridine, azirine, azetidine, azeto, azolidine, azole, azinane, pyridine, azepan, azepine, imidazole, pyrazole, oxazole, thiazole, imidazoline, pyrazine, morpholine, thiazine, indole , Isoindole, benzimidazole, purine, quinoline, isoquinoline, quinoxaline, cinnoline, pteridine, acridine, carbazole, benzo-C-cinnoline, porphyrin, chlorin, choline and the like.

〔一般式（１）において、Ｅ_１〜Ｅ_８は、それぞれ独立にＣ（Ｒｂ）又は窒素原子を表し、Ｅ_１〜Ｅ_４のうちの一つが窒素原子であり、Ｅ_５〜_８のうちの一つが窒素原子である。Ｒａ及びＲｂは、それぞれ独立に、水素原子又は置換基を表す。〕Moreover, it is preferable that the compound which has a heterocyclic ring which uses a nitrogen atom as a hetero atom is a compound which has a structure represented by following General formula (1).

[In General Formula (1), E _{1 to} E ₈ each independently represent C (Rb) or a nitrogen atom, _one of E _{1 to} E ₄ is a nitrogen atom, and one of E ₅ to ₈ One is a nitrogen atom. Ra and Rb each independently represents a hydrogen atom or a substituent. ]

  Examples of substituents represented by Ra and Rb include alkyl groups (eg, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group). Group, pentadecyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, etc.), alkynyl group (eg, ethynyl group, propargyl group, etc.), aromatic carbonization Hydrogen group (also called aromatic carbocyclic group, aryl group, etc., for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl Group, indenyl group, pyrenyl group, biphenylyl group), aromatic compound Ring group (for example, furyl group, thienyl group, pyridyl group, pyridazinyl group, pyrimidinyl group, pyrazinyl group, triazinyl group, imidazolyl group, pyrazolyl group, thiazolyl group, quinazolinyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (Indicates that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), a phthalazinyl group, etc.), a heterocyclic group (for example, a pyrrolidyl group, an imidazolidyl group, a morpholyl group, an oxazolidyl group, etc. ), Alkoxy groups (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy groups (for example, cyclopentyloxy group, cyclohexyloxy group, etc.) , Aryloxy (For example, phenoxy group, naphthyloxy group, etc.), alkylthio group (for example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (for example, cyclopentylthio group, Cyclohexylthio group etc.), arylthio group (eg phenylthio group, naphthylthio group etc.), alkoxycarbonyl group (eg methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group etc.) ), Aryloxycarbonyl groups (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl groups (eg, aminosulfonyl group, methylaminosulfonyl group, dimethyl) Aminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group ( For example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy Group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group) Si group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino) Group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylamino) Carbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, Nylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group) Naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group) , 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexyls) Sulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, Ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, piperidyl group (also referred to as piperidinyl group), 2,2 , 6,6-tetramethylpiperidinyl group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trifluoromethyl group, pentafluoroethyl) Group, pentafluorophenyl group, etc. , Cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.), phosphate group (for example, dihexyl phosphoryl group, etc.) Phosphite group (for example, diphenylphosphinyl group) and phosphono group.

Some of these substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.
Among them, the substituent represented by Ra and Rb is preferably an aromatic hydrocarbon ring or an aromatic heterocyclic ring from the viewpoint of enhancing the interaction with silver or copper, and includes a phenyl group and an aromatic group containing a nitrogen atom. Heterocycle is more preferable, a 6-membered ring containing a nitrogen atom or a condensed ring containing the 6-membered ring as a mother nucleus (for example, phenanthroline, carboline, etc.), a 5-membered ring containing a nitrogen atom or the 5-membered ring as a mother nucleus Containing fused rings are preferred.

〔上記一般式（２）において、Ｅ_２１〜Ｅ_２６は、Ｃ（Ｒｄ）を表す。Ｒｃ及びＲｄは、それぞれ独立に、水素原子又は置換基を表す。〕Moreover, it is preferable that the compound which has a heterocyclic ring which uses a nitrogen atom as a hetero atom is a compound which has a structure represented by following General formula (2).

[In the general formula _{(2), E} 21 ~E ₂₆ represents C (Rd). Rc and Rd each independently represents a hydrogen atom or a substituent. ]

  Examples of the substituent represented by Rc and Rd include the same substituents as Ra and Rb in the general formula (1), and preferred substituents include the same substituents as the preferred substituents of Ra and Rb. .

〔上記一般式（３）において、Ｅ_３１〜Ｅ_４２は、Ｃ（Ｒｅ）を表す。Ｒｅは、水素原子又は置換基を表す。Ｌ_０は、アリーレン基、ヘテロアリーレン基又はそれらの組み合わせからなる２価の連結基を表す。〕Moreover, it is preferable that the compound which has a heterocyclic ring which uses a nitrogen atom as a hetero atom is a compound which has a structure represented by following General formula (3).

[In the above general formula (3), E _{31 to} E ₄₂ represent C (Re). Re represents a hydrogen atom or a substituent. L ₀ represents a divalent linking group composed of an arylene group, a heteroarylene group, or a combination thereof. ]

  Examples of the substituent represented by Re include the same substituents as those of Rb in the general formula (1), and preferable substituents include the same substituents as the preferable substituents of Rb.

〔上記一般式（４）において、Ｒ_１〜Ｒ_３は、それぞれ独立に、水素原子又は置換基を表す。Ｌ_１は、窒素原子と結合している芳香族炭化水素環基又は芳香族複素環基を表す。〕Moreover, it is preferable that the compound which has a heterocyclic ring which uses a nitrogen atom as a hetero atom is a compound which has a structure represented by following General formula (4).

[In the said General formula (4), R < ₁ > -R < ₃ > represents a hydrogen atom or a substituent each independently. L ₁ represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group bonded to a nitrogen atom. ]

Examples of the substituent represented by R _{1 to} R ₃ include the same substituent as the substituent represented by Ra in the general formula (1), and the preferred substituent is the same as the preferred substituent of Ra. Can be mentioned.

L ₁ is an aromatic hydrocarbon group (also referred to as an aromatic carbocyclic group or an aryl group) or an aromatic heterocyclic group (also referred to as a heteroaryl group), and has an aromatic six-membered ring skeleton. preferable.
As the aromatic hydrocarbon group, for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, And biphenylyl group.
Examples of the aromatic heterocyclic group include a pyridyl group, a pyridazyl group, a pyrimidyl group, a pyrazyl group, and a triazyl group.

L ₁ preferably has a benzene ring skeleton or a triazine ring skeleton. Here, the aromatic six-membered ring skeleton, the benzene ring skeleton, and the triazine ring skeleton represent that each partial structure is included.

〔上記一般式（５）において、Ｒ_４〜Ｒ_９は、それぞれ独立に、水素原子又は置換基を表す。Ｌ_２は、芳香族炭化水素環基又は芳香族複素環基を表す。Ｘ_１〜Ｘ_３は、それぞれ独立に、窒素原子又はＣＲ_１０を表す。Ｒ_１０は、水素原子又は置換基を表す。〕Moreover, it is preferable that the compound which has a heterocyclic ring which uses a nitrogen atom as a hetero atom is a compound which has a structure represented by following General formula (5).

[In the said General formula (5), R < ₄ > -R < ₉ > represents a hydrogen atom or a substituent each independently. L ₂ represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group. X _{1 to} X ₃ each independently represent a nitrogen atom or CR ₁₀ . R ₁₀ represents a hydrogen atom or a substituent. ]

Examples of the substituent represented by R _{4 to} R ₁₀ include the same substituents as the substituent represented by Ra and Rb in the general formula (1), and the preferred substituents are also the same as the preferred substituents of Ra and Rb. The substituent of this is mentioned.
Examples of the substituent L ₂ represents include the same substituents as L ₁ in the general formula (4).

〔上記一般式（６）において、Ｒ_１１〜Ｒ_１６は、それぞれ独立に、水素原子又は置換基を表す。Ｘ_４〜Ｘ_６は、それぞれ独立に、窒素原子又はＣＲ_１７を表す。Ｙ_１〜Ｙ_４は、それぞれ独立に、窒素原子又はＣＲ_１８を表し、これらが互いに結合して新たな環を形成しても良い。Ｚ_１〜Ｚ_４は、それぞれ独立に、窒素原子又はＣＲ_１９を表し、少なくとも一つは窒素原子を表す。Ｚ_１〜Ｚ_４は互いに結合して新たな環を形成してもよい。Ｒ_１７、Ｒ_１８及びＲ_１９は、それぞれ独立に、水素原子又は置換基を表す〕Moreover, it is preferable that the compound which has a heterocyclic ring which uses a nitrogen atom as a hetero atom is a compound which has a structure represented by following General formula (6).

[In the general formula _{(6), R} 11 ~R ₁₆ independently represents a hydrogen atom or a substituent. X _{4 to} X ₆ each independently represent a nitrogen atom or CR ₁₇ . Y _{1 to} Y ₄ each independently represent a nitrogen atom or CR ₁₈ , and these may be bonded to each other to form a new ring. Z _{1 to} Z ₄ each independently represent a nitrogen atom or CR ₁₉ , and at least one represents a nitrogen atom. Z _{1 to} Z ₄ may be bonded to each other to form a new ring. R ₁₇ , R ₁₈ and R ₁₉ each independently represents a hydrogen atom or a substituent.

Examples of the substituent represented by R _{11 to} R ₁₉ include the same substituent as the substituent represented by Ra and Rb in the general formula (1), and the preferred substituent is the same as the preferred substituent of Ra and Rb. The substituent of this is mentioned.

  Hereinafter, exemplary compounds (1-1) to (1-33), which are compounds having a structure represented by any one of the above general formulas (1) to (6), are shown, but not limited thereto.

  The compound containing a sulfur atom may have a sulfide bond (also referred to as a thioether bond), a disulfide bond, a mercapto group, a sulfone group, a thiocarbonyl bond, or the like in the molecule, particularly a sulfide bond or a mercapto group. It is preferable.

〔上記一般式（７）において、Ｒ_１０１及びＲ_１０２は、それぞれ独立に、置換基を表す。〕Specifically, the compound containing a sulfur atom is preferably a compound having a structure represented by any of the following general formulas (7) to (10).

[In the general formula (7), R ₁₀₁ and R ₁₀₂ each independently represents a substituent. ]

〔上記一般式（８）において、Ｒ_１０３及びＲ_１０４は、それぞれ独立に、置換基を表す。〕

[In the general formula (8), R ₁₀₃ and R ₁₀₄ each independently represents a substituent. ]

〔上記一般式（９）において、Ｒ_１０５は、置換基を表す。〕

[In the general formula (9), R ₁₀₅ represents a substituent. ]

〔上記一般式（１０）において、Ｒ_１０６は、置換基を表す。〕

[In the above general formula (10), R ₁₀₆ represents a substituent. ]

Examples of the substituent represented by R _{101 to} R ₁₀₆ include an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aromatic hydrocarbon group, an aromatic heterocyclic group, a heterocyclic group, an alkoxy group, a cycloalkoxy group, and an aryloxy group. Groups and the like.

  Hereinafter, exemplary compounds (2-1) to (2-44), which are compounds having a structure represented by any one of the general formulas (7) to (10), are shown, but not limited thereto.

  The layer thickness of the underlayer Eb is preferably in the range of 3 to 200 nm, and more preferably in the range of 10 to 100 nm, from the viewpoint of obtaining sufficient continuous film formability of the electrode layer Ea.

In order to more effectively prevent movement of silver atoms or copper atoms during film formation of the electrode layer Ea, MoO ₃ , Al, Pd, Fe, Mn, Ga, Ge, In, and the like are interposed between the base layer Eb and the electrode layer Ea. In addition, a migration preventing layer containing at least one of Ni, Co, and Co metal elements can be provided. Since the metal element contained in the movement preventing layer interacts with silver or copper in the electrode layer Ea, the movement of silver atoms or copper atoms during the formation of the electrode layer Ea is suppressed, and the electrode having a thin and uniform layer thickness The layer Ea can be formed.
The thickness of the migration preventing layer is preferably 1 nm or less. If the layer thickness is 1 nm or less, the interaction between the organic functional layer 3 and the electrode layer Ea is not inhibited. In addition, due to the synergistic effect of the interaction between the organic functional layer 3 and the electrode layer Ea and the interaction between the movement prevention layer and the electrode layer Ea, the uniformity of the layer thickness of the electrode layer Ea can be further increased. The flatness of the Ea surface is further improved.

(Electrode layer)
The electrode layer Ea is formed on the base layer Eb using silver or a silver alloy, or copper or a copper alloy. Specifically, the electrode layer Ea is a metal layer containing silver or copper as a main component, and containing as a main component has the largest content mass ratio (% by mass) among the elements in the electrode layer Ea. That means. Since silver and copper are inexpensive, the cost of the transparent electrode E1 can be reduced.
The electrode layer Ea may have a multilayer structure in which a plurality of metal layers using silver or a silver alloy, or copper or a copper alloy are stacked.

Examples of the silver alloy that can be used as the electrode layer Ea include silver magnesium (AgMg), silver copper (AgCu), silver palladium (AgPd), silver palladium copper (AgPdCu), silver indium (AgIn), and the like.
Examples of the copper alloy that can be used as the electrode layer Ea include copper magnesium and copper palladium.

  The electrode layer Ea preferably has a layer thickness in the range of 4 to 15 nm. When the layer thickness is within this range, sufficient conductivity is obtained, and the light transmittance of the electrode layer Ea is improved.

[Drawer wiring]
The lead-out wiring 5 is provided for electrically connecting the transparent electrode E1 to an external power source.
The material of the lead wiring 5 is not particularly limited, and a known material can be used. For example, besides the MAM (Mo / Al · Nd alloy / Mo) having a three-layer structure, the same material as the electrode E2 can be used.
The thickness of the lead-out wiring 5 is not particularly limited, but is preferably 1 μm or more because the resistance can be reduced. From the viewpoint of cost required for film formation and ease of film formation, it is preferably in the range of 50 to 500 nm.

[Electrode paired with transparent electrode]
The electrode E2 is an electrode that makes a pair with the transparent electrode E1, and is provided as a cathode in the organic EL element 10.
As a material of the electrode E2, a metal, an alloy, an organic or inorganic conductive compound, or a mixture thereof is used. Specifically, gold, aluminum, silver, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, indium, lithium / aluminum mixture, rare earth metal, ITO, ZnO, TiO ₂ and oxide semiconductors such as SnO ₂ .

The sheet resistance as the electrode E2 is preferably several hundred Ω / □ or less.
The layer thickness of the electrode E2 is usually in the range of 5 nm to 5 μm, preferably in the range of 5 to 200 nm.

[Organic functional layer]
The organic functional layer 3 includes at least a light emitting layer 3c, and may include a hole injection layer 3a, a hole transport layer 3b, an electron transport layer 3d, or an electron injection layer 3e as necessary.

(Light emitting layer)
The light emitting layer 3c is a layer that emits light by recombination of electrons injected from the electrode E2 or the electron transport layer 3d and holes injected from the transparent electrode E1 or the hole transport layer 3b. Light emission may occur in the layer of the light emitting layer 3c, or may occur at the interface between the light emitting layer 3c and an adjacent layer.

  The configuration of the light emitting layer 3c is not particularly limited as long as the included light emitting material satisfies the light emission requirements. Moreover, there may be a plurality of layers having the same emission spectrum and emission maximum wavelength. In this case, it is preferable to have a non-light emitting intermediate layer between the light emitting layers.

  The total thickness of the light emitting layer 3c is preferably in the range of 1 to 100 nm, and more preferably in the range of 1 to 30 nm because a lower driving voltage can be obtained. In addition, the sum total of the layer thickness of the light emitting layer 3c is a layer thickness also including the said intermediate | middle layer, when a nonluminous intermediate | middle layer exists between light emitting layers.

  When the light emitting layer 3c has a multilayer structure in which a plurality of light emitting layers are laminated, the thickness of each light emitting layer is preferably adjusted within the range of 1 to 50 nm, more preferably within the range of 1 to 20 nm. Is to adjust in. In the case where the plurality of stacked light emitting layers correspond to the respective emission colors of blue, green and red, the relationship between the thicknesses of the blue, green and red light emitting layers is not particularly limited.

  The light emitting layer 3c may be used by mixing a plurality of light emitting materials in the same light emitting layer. Among these, the light emitting layer 3c preferably contains a host compound (also referred to as a light emitting host) and a light emitting material (also referred to as a light emitting dopant) and emits light using the light emitting material.

(Host compound)
As the host compound contained in the light emitting layer 3c, a compound having a phosphorescence quantum yield of phosphorescence emission at room temperature (25 ° C.) of less than 0.1 is preferable. Further, the phosphorescence quantum yield is preferably less than 0.01.
The host compound preferably has a volume ratio of 50% or more with respect to the entire compound contained in the light emitting layer 3c.

As a host compound, a well-known host compound may be used independently and multiple types of host compounds may be used. By using a plurality of types of host compounds, it is possible to adjust the movement of carriers, and the external quantum efficiency of the organic EL element 10 can be increased. The external quantum efficiency refers to the ratio of the number of photons taken out of the organic EL element to the number of electrons injected into the organic EL element, and is represented by the product of the internal quantum efficiency and the light extraction efficiency. The internal quantum efficiency is the ratio of the number of photons generated in the light emitting layer 3c to the number of electrons injected into the organic EL element, and the light extraction efficiency is the organic EL element relative to the number of photons generated in the light emitting layer 3c. This is the ratio of the number of photons extracted to the outside.
In addition, when a plurality of types of light emitting materials described later are used, it is possible to mix light emission having different light emission colors, whereby an arbitrary light emission color can be obtained.

  The host compound used in the light emitting layer 3c may be a conventionally known low molecular compound or a high molecular compound having a repeating unit, and a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (evaporation polymerization light emission). Host).

(Luminescent material)
As the light-emitting material, a phosphorescent compound (also referred to as a phosphorescent compound or a phosphorescent material) or a fluorescent compound (also referred to as a fluorescent compound or a fluorescent material) can be given.

(Phosphorescent compound)
A phosphorescent compound is a compound in which light emission from an excited triplet is observed. Specifically, it is a compound that emits phosphorescence at room temperature (25 ° C.), and the phosphorescence quantum yield is 0 at 25 ° C. A preferred phosphorescence quantum yield is 0.10 or more, although it is defined to be a compound of 0.01 or more.

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. The phosphorescence quantum yield in the solution can be measured using various solvents, but when using a phosphorescent compound, the phosphorescence quantum yield of 0.01 or more is achieved in any solvent. Just do it.

As the light emission principle of the phosphorescent compound, there can be mentioned two types of energy transfer type and carrier trap type.
In the case of the energy transfer type, carrier recombination occurs on the host compound to which carriers are transported, and an excited state of the host compound is generated. Light emitted from the phosphorescent compound is obtained by transferring the energy generated at this time from the host compound to the phosphorescent compound.
In the case of the carrier trap type, when the phosphorescent compound traps the carrier, carrier recombination occurs on the phosphorescent compound, and light emission from the phosphorescent compound is obtained.
In any case, the condition is that the excited state energy level of the phosphorescent compound is lower than the excited state energy level of the host compound.

  The phosphorescent compound can be appropriately selected from known materials used in the light emitting layer of a general organic EL device, but preferably contains a group 8-10 metal in the periodic table of elements. It is a metal complex. Among metal complexes, iridium complexes, osmium complexes, platinum complexes, and rare earth complexes are more preferable, and iridium complexes are the most preferable.

(Fluorescent compound)
Fluorescent compounds include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes, stilbene dyes. System dyes, polythiophene dyes, rare earth complex phosphors, and the like.

(Injection layer: hole injection layer, electron injection layer)
The hole injection layer 3a and the electron injection layer 3e are injection layers provided between the pair of electrodes and the light emitting layer in order to lower the driving voltage and improve the light emission luminance.

The hole injection layer 3a is disposed between the transparent electrode E1 and the hole transport layer 3b adjacent to the transparent electrode E1 that is an anode.
The details of the hole injection layer 3a are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like in addition to the above documents.

  Examples of the material used for the hole injection layer 3a include porphyrin derivatives, phthalocyanine derivatives, oxazole derivatives, oxadiazole derivatives, triazole derivatives, imidazole derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, hydrazone derivatives, stilbene derivatives, poly Introduction of arylalkane derivatives, triarylamine derivatives, carbazole derivatives, indolocarbazole derivatives, isoindole derivatives, acene derivatives such as anthracene and naphthalene, fluorene derivatives, fluorenone derivatives, polyvinylcarbazole, aromatic amines in the main chain or side chain Polymer materials or oligomers, polysilanes, conductive polymers or conductive oligomers (eg PEDOT (polyethylenedioxythiophene), P S (polystyrene sulfonic acid), aniline copolymers, polyaniline, and polythiophene, etc.) and the like.

  Examples of the triarylamine derivative include a benzidine type represented by α-NPD (4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl), MTDATA (4,4 ′, 4 ″- Examples thereof include a starburst type represented by tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine) and a compound having fluorene or anthracene in the triarylamine-linked core.

  Further, hexaazatriphenylene derivatives as described in JP-T-2003-519432, JP-A-2006-135145 and the like can also be used as the material for the hole transport layer 3b.

The electron injection layer 3e is disposed between the electrode E2 and the light emitting layer 3c adjacent to the electrode E2 which is a cathode.
Materials used for the electron injection layer 3e include metals such as strontium and aluminum, alkali metal compounds such as lithium fluoride, sodium fluoride, and potassium fluoride, magnesium fluoride, and calcium fluoride. Representative alkali metal halide layer, alkaline earth metal compound layer typified by magnesium fluoride, metal oxide typified by molybdenum oxide, aluminum oxide, etc., typified by lithium 8-hydroxyquinolate (Liq), etc. A metal complex etc. are mentioned. When the transparent electrode E1 is a cathode, an organic material such as a metal complex is particularly preferably used.
The electron injection layer 3e is desirably a very thin film, and although depending on the constituent materials, the layer thickness is preferably in the range of 1 nm to 10 μm.

(Hole transport layer)
The hole transport layer 3b is a layer that transports holes from the hole injection layer 3a to the light emitting layer 3c. Moreover, the hole transport layer 3b also acts as a barrier that prevents the inflow of electrons from the cathode side. Therefore, the hole transport layer 3b may be formed to function as a hole injection layer, an electron blocking layer, or both. The hole transport layer 3b may be a single layer or a plurality of layers.

As a material used for the hole transport layer 3b, any of an organic compound and an inorganic compound can be used as a material as long as the function of transporting holes and the function of blocking the inflow of electrons can be expressed.
Examples of the material for the hole transport layer 3b include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styryl. Anthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, conductive polymer oligomers, and offene oligomers may be mentioned.
In addition, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (abbreviation: α-NPD), three triphenylamine units described in JP-A-4-308688 are used. 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine (abbreviation: MTDATA) or the like linked in a starburst type can also be used.

(Electron transport layer)
The electron transport layer 3d is a layer that transports electrons from the electron injection layer 3e to the light emitting layer 3c. The electron transport layer 3d also acts as a barrier that prevents the inflow of holes from the anode side. Therefore, the electron transport layer 3d may be formed to function as an electron injection layer, a hole blocking layer, or both.

As a material of the electron transport layer 3d, a conventionally known compound can be used as long as it is a material that also serves as a hole blocking material and has a function of transmitting (transporting) electrons injected from the cathode to the light emitting layer 3c.
Examples of conventionally known materials for the electron transport layer 3d include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane, anthrone derivatives, oxadiazole derivatives, and the like. Can be mentioned. Further, in the above oxadiazole derivative, a thiadiazole derivative in which an oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group are also used as the material for the electron transport layer 3d. Can do. Furthermore, a polymer material in which these materials are introduced into a polymer chain, or a polymer material having these materials as a polymer main chain can also be used.

In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (abbreviation: Alq ₃ ), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) ) Aluminum, tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (abbreviation: Znq), etc. and the central metal of these metal complexes is In Metal complexes replaced with Mg, Cu, Ca, Sn, Ga, or Pb can also be used as the material for the electron transport layer 3d.

The electron transport layer 3d may have a single structure made of one or more of the above materials.
Further, as the material of the electron transport layer 3d, the same material as that constituting the intermediate layer described above may be used. The same applies to the electron transport layer 3d also serving as the electron injection layer, and the same material as that constituting the intermediate layer described above may be used.

  Although there is no restriction | limiting in particular about the layer thickness of 3 d of electron carrying layers, Usually, 5 nm-about 5 micrometers, Preferably it exists in the range of 5-200 nm.

(Blocking layer)
The organic functional layer 3 can also include a blocking layer as necessary in addition to the above-described layers.
Examples of the blocking layer include a hole blocking layer and an electron blocking layer.
The hole blocking layer has a function of an electron transport layer in a broad sense. By using a hole blocking material that has a large electron transporting capability and a very small hole transporting capability as the material for the hole blocking layer, it is possible to block holes while transporting electrons. The coupling probability can be improved. The hole blocking layer is preferably provided adjacent to the light emitting layer 3c.

On the other hand, the electron blocking layer has a function of a hole transport layer in a broad sense. By using an electron device material that has a large hole-transporting ability and extremely small electron-transporting ability as the material for the electron-blocking layer, it can block electrons while transporting holes, and the probability of recombination of electrons and holes. Can be improved.
The layer thickness of the hole blocking layer or the electron blocking layer is preferably in the range of 3 to 100 nm, more preferably in the range of 5 to 30 nm.

(Encapsulant)
The sealing material 6 is provided for sealing the organic EL element 10. As shown in FIG. 1, the sealing material 6 is bonded to the electrode E <b> 2 and the lead-out wiring 5 with an adhesive 7.
The sealing material 6 can be, for example, a concave plate or a film. The transparency and electrical insulation of the sealing material 6 are not particularly limited.

As the sealing material 6, a plate material such as a glass plate, a polymer plate, a metal plate, a film obtained by further thinning these plate materials, or the like can be used.
Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz. Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.
In order to make the plate material concave, sandblasting or chemical etching may be performed.

As the sealing material 6, a polymer film or a metal film can be preferably used from the viewpoint of thinning the organic EL element 10.
The polymer film preferably has a gas barrier layer as with the substrate 1. The gas barrier layer has a water vapor transmission rate of 1 × 10 ⁻³ g / m ² · 24 h at a temperature of 25 ± 0.5 ° C. and a relative humidity of 90 ± 2% RH measured by a method according to JIS K 7129-1992. The oxygen permeability measured by a method according to JIS K 7126-1987 is preferably 1 × 10 ⁻³ ml / m ² · 24 h · atm (1 atm is 1.01325 × 10 ⁵ Pa amount of) or less, the temperature 25 ± 0.5 ° C., water vapor permeability at a relative humidity of 90 ± 2% RH is preferably not more than ^{1 × 10 -3 g / m 2} · 24h.

Specific examples of the adhesive 7 include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing types such as 2-cyanoacrylates. Examples thereof include adhesives, epoxy-based heat and chemical curing type (two-component mixed) adhesives, and the like. Moreover, hot-melt type polyamide, polyester, polyolefin, and a cationic curing type ultraviolet curable epoxy resin adhesive can be mentioned.
For the application of the adhesive 7, a commercially available dispenser may be used, or printing may be performed like screen printing.

[Method for producing organic EL element]
As an embodiment of the method for producing an organic EL element of the present invention, a method for producing the organic EL element 10 described above will be described.
The organic EL element 10 can be manufactured as follows.

  A bleed-out prevention layer, a planarization layer, and a gas barrier layer are formed on the substrate 1 as necessary. For example, when the gas barrier layer is formed from an inorganic precursor compound such as polysilazane, a coating solution of the inorganic precursor compound is applied onto the substrate 1. After the coating film is dried, a gas barrier layer is formed by modifying the film by irradiating ultraviolet rays or the like.

Next, the light scattering layer 21 is formed so as to overlap the region of the light emitting layer 3c on the substrate 1, that is, in the region where the main body portion a1 of the electrode layer Ea is formed. Thereby, the light-scattering layer 21 can be formed under the main body part a1 of the electrode layer Ea. In the case where the light scattering layer 21 is also formed under the conductor portion a2 of the electrode layer Ea, the light scattering layer 21 is also formed in the region where the conductor portion a2 is formed.
As shown in FIG. 3, when one end 22 p of the smooth layer 22 is positioned closer to the lead-out wiring 5 than the one end 21 p of the light scattering layer 21, a main body portion a <b> 1 is formed as a region for forming the light scattering layer 21. What is necessary is just to make it smaller than the area to be.

In the case of forming the light scattering layer 21 containing light scattering particles, a dispersion obtained by dispersing the light scattering particles in the layer medium is applied onto the substrate 1. The application method is not limited, and for example, an inkjet method or the like can be used.
On the other hand, the light scattering layer 21 having an uneven structure can be formed by an imprint method. Specifically, after a polymer film made of a thermoplastic resin or the like is formed on the substrate 1, the thermoplastic resin is heated and pressed with a mold provided with unevenness to transfer the uneven shape of the mold. Can be formed. Alternatively, the light scattering layer 21 having the concavo-convex structure can also be formed by applying an ultraviolet curable resin on the substrate 1 and then curing it by irradiating ultraviolet rays in a state where the mold provided with the concavo-convex is in close contact. Can do.

The light scattering layer 21 having a concavo-convex structure can also be formed by etching an inorganic oxide such as silicon oxide that is a gas barrier layer. In this case, reactive ion etching or the like can be used.
In addition, a concavo-convex structure can also be formed by preparing a gel-like inorganic oxide film using a sol-gel technique and then pressing and heating a mold having ruggedness on the gel-like film. it can.

When the smooth layer 22 is further formed, the smooth layer 22 is formed so as to overlap the region of the light emitting layer 3c, that is, in a region where the main body portion a1 of the electrode layer Ea is formed. Thereby, the smooth layer 22 can be formed under the main body portion a1. Specifically, a dispersion obtained by dispersing particles having a high refractive index in the layer medium is applied onto the light scattering layer 21. As the coating method, an ink jet method or the like can be used similarly to the light scattering layer 21.
In the case where the smooth layer 22 is also formed under the conductor portion a2 of the electrode layer Ea, the smooth layer 22 is also formed in a region where the conductor portion a2 is formed.

  Next, the base layer Eb is formed in both the region where the main body portion a1 of the electrode layer Ea on the light scattering layer 21 or the smooth layer 22 is formed and the region where the conductive wire portion a2 is formed. Furthermore, the transparent electrode E1 is formed by forming the main body part a1 and the conducting wire part a2 of the electrode layer Ea on the base layer Eb.

As a method for forming the underlayer Eb, a wet process such as a coating method, an inkjet method, a dip method, a resistance heating method, a vapor deposition method such as an EB (E1ectron Beam) method, a sputtering method, a CVD method
A dry process such as the (Chemical Vapor Deposition) method can be used. Of these, vapor deposition is preferred.
As a method for forming the electrode layer Ea, a known method such as a resistance heating method, an evaporation method such as an EB method, or a sputtering method can be used.
For example, a mask can be used to form the base layer Eb and the electrode layer Ea.

When the transparent electrode E1 is formed, the lead-out wiring 5 is formed so as to overlap at least a part of the conducting wire part a2 of the electrode layer Ea. As long as at least one part overlaps, you may overlap all the conducting wire part a2.
For the formation of the lead-out wiring 5, a vapor deposition method or the like can be used similarly to the electrode layer Ea.

Next, each of these layers is formed in the order of the hole injection layer 3a, the hole transport layer 3b, the light emitting layer 3c, the electron transport layer 3d, and the electron injection layer 3e on the transparent electrode E1, thereby forming the organic functional layer 3. Each layer consists of spin coating method, casting method, LB method (Langmuir Blodgett method), inkjet method,
Although it can be formed by a vacuum deposition method, a printing method, or the like, a vacuum deposition method or a spin coating method is preferable because a homogeneous film is easily obtained and pinholes are hardly generated. Different formation methods may be employed for each layer.

When each layer is formed by a vapor deposition method, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 to 450 ° C., a vacuum degree of 1 × 10 ⁻⁶ to 1 × 10 ⁻² Pa, and a vapor deposition rate of 0. It is desirable to select each condition as appropriate within a range of 0.01 to 50 nm / second, a substrate temperature of −50 to 300 ° C., and a layer thickness of 0.1 to 5 μm.

  When the organic functional layer 3 is formed, the electrode E <b> 2 is formed on the organic functional layer 3. Specifically, the electrode E <b> 2 is formed so as to overlap the region of the organic functional layer 3 and to be exposed on the opposite side of the lead-out wiring 5 while being insulated from the transparent electrode E <b> 1 by the organic functional layer 3. As a method for forming the electrode E2, a vapor deposition method, a sputtering method, or the like similar to the electrode layer Ea of the transparent electrode E1 can be used.

When the electrodes E2 are formed, the sealing material 6 covers the organic functional layer 3 and the like on the substrate 1, and then the sealing material 6 is bonded to the electrode E2 and the lead-out wiring 5 with the adhesive 7.
When the external light extraction layer 2B is provided, the external light extraction layer 2B is attached to the surface of the substrate 1 opposite to the internal light extraction layer 2A.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless there is particular notice, it represents "mass part" or "mass%".

[Organic EL element 101]
A polyethylene naphthalate (PEN) film (produced by Teijin DuPont Films Ltd., extremely low heat yield PENQ83) having a width of 500 mm and a layer thickness of 125 μm was prepared as a substrate. On one side of this substrate, UV curable organic / inorganic hybrid hard coat material OPSTAR Z7535 (manufactured by JSR Corporation) was applied so that the layer thickness after drying was 4 μm. Thereafter, using a high-pressure mercury lamp, ultraviolet rays were irradiated at 1.0 J / cm ² in an air atmosphere, and dried and cured at a temperature of 80 ° C. for 3 minutes to form a bleed-out prevention layer.

Subsequently, a UV curable organic / inorganic hybrid hard coat material OPSTAR Z7501 (manufactured by JSR Corporation) was applied to the opposite surface of the substrate so that the layer thickness after drying was 4 μm. Thereafter, using a high-pressure mercury lamp, ultraviolet rays were irradiated at 1.0 J / cm ² in an air atmosphere, dried at a temperature of 80 ° C. for 3 minutes, and cured to form a flattened layer.

The maximum planar height Rt (p) of the obtained planarized layer was 16 nm in terms of the surface roughness specified by JIS B 0601.
The surface roughness was measured using an AFM (Atomic Force Microscope) SPI3800N DFM manufactured by SII. The measurement range of one time was 80 μm × 80 μm, the measurement location was changed, and the measurement was performed three times, and the average of the Rt values obtained in each measurement was used as the measurement value.
The layer thickness of the substrate on which the bleed-out prevention layer and the planarization layer were formed was 133 μm.

  Subsequently, the coating liquid containing an inorganic precursor compound was apply | coated on the planarization layer of a board | substrate using the coater of the reduced pressure extrusion system, and it dried and formed the 1st gas barrier layer. The coating solution was applied so that the dry layer thickness was 150 nm. Drying was performed under conditions of a drying temperature of 80 ° C., a drying time of 300 seconds, and a dew point of 5 ° C. in the drying atmosphere.

  The coating liquid containing the inorganic precursor compound is a non-catalytic perhydropolysilazane 20% by mass dibutyl ether solution (Aquamica NN120-20, manufactured by AZ Electronic Materials) and a par containing 5% by mass of the amine catalyst in solids. A hydropolysilazane 20% by mass dibutyl ether solution (Aquamica NAX120-20, manufactured by AZ Electronic Materials) was mixed and used to adjust the amine catalyst to 1% by mass of solid content, and then further diluted with dibutyl ether. It was prepared as a 5 mass% dibutyl ether solution.

After drying, the substrate was gradually cooled to 25 ° C., and the coating surface was subjected to modification treatment by irradiation with vacuum ultraviolet rays in a vacuum ultraviolet irradiation apparatus. As a light source of the vacuum ultraviolet irradiation device, an Xe excimer lamp having a double tube structure for irradiating vacuum ultraviolet rays having a wavelength of 172 nm was used.
In each of the coating, drying, and modification processes, uniform tension was applied to the substrate by a tension control mechanism.

After the modification treatment, the substrate on which the gas barrier layer was formed was dried under the same drying conditions as described above. After drying, a second modification treatment was performed to form a gas barrier layer having a layer thickness after drying of 150 nm.
Next, in the same manner as the first gas barrier layer, a second gas barrier layer was formed on the first gas barrier layer to obtain a substrate having a multilayer gas barrier layer.

After the substrate having the gas barrier layer was cut into a size of 6.0 cm × 6.0 cm, a light scattering layer was formed on the substrate as follows.
A TiO ₂ particle JR600A having a refractive index of 2.4 and an average particle diameter of 0.25 μm (manufactured by Teica) and an organic-inorganic hybrid resin solution ED230AL (manufactured by APM) having a solid content ratio (volume%) of 70: The mixture was mixed so that the solid content concentration of the coating solution was 15% by mass to prepare a light scattering layer coating solution of 10 ml in total. In the coating solution, hexylene glycol, propylene glycol monomethyl ether and isopropyl alcohol were used as solvents, and the solvent ratio (mass ratio) in these coating solutions was set to 30:50:20.

Specifically, the above-mentioned TiO ₂ particles and the above-mentioned solvent are mixed, and while cooling at room temperature, an ultrasonic disperser UH-50 (manufactured by SMT Co.) is used for microchip step MS-3 3 mmφ (manufactured by SMT Co.). Dispersion of TiO ₂ particles was prepared by dispersing for 10 minutes under standard conditions.
While stirring this dispersion at 100 rpm, the organic-inorganic hybrid resin solution was added little by little. When all the additions were completed, the stirring speed was increased to 500 rpm, mixed for 10 minutes, and filtered through a hydrophobic PVDF 0.45 μm filter (manufactured by Whatman) to obtain a coating solution for the light scattering layer.

  The obtained coating solution was applied to a 4.0 cm × 4.0 cm region in the center of the substrate as shown in FIG. 6 by an inkjet method. Thereafter, simple drying was performed at a temperature of 80 ° C. for 2 minutes, and further, baking was performed at a temperature of 120 ° C. for 6 minutes to form a light scattering layer. The layer thickness of the light scattering layer was 500 nm.

A smooth layer was formed on the formed light scattering layer as follows.
The dispersion ratio HDT-760T of nano TiO ₂ particles having an average particle size of 0.02 μm (manufactured by Teika) and the organic-inorganic hybrid resin solution ED230AL (manufactured by APM) having a solid content ratio (volume%) of 45: Thus, the coating solution was mixed so that the solid concentration of the coating solution was 20% by mass to prepare a coating solution for a smooth layer having a total amount of 10 ml. In the coating solution, hexylene glycol, propylene glycol monomethyl ether and isopropyl alcohol were used as solvents, and the respective solvent ratios (mass%) were set to 30:50:20.

Specifically, the dispersion liquid of the nano TiO ₂ particles and the solvent were mixed, and the organic-inorganic hybrid resin solution was added little by little while stirring at a stirring speed of 100 rpm. When all was added, the stirring speed was increased to 500 rpm, and the mixed liquid obtained by mixing for 10 minutes was filtered with a hydrophobic PVDF 0.45 μm filter (manufactured by Whatman) to obtain a coating solution for a smooth layer. .

  The smoothing layer coating solution was applied to a 4.0 cm × 4.0 cm region in the center of the substrate by an ink jet method so as to overlap the light scattering layer. After performing simple drying at a temperature of 80 ° C. for 2 minutes, firing was further performed at a temperature of 120 ° C. for 30 minutes to form a smooth layer. The layer thickness of the smooth layer was 700 nm. The refractive index of the smooth layer single film was 1.85.

The internal light extraction layer composed of the light scattering layer and the smooth layer had a light transmittance of 67% and a haze value Hz of 50%.
Further, based on ASTM D542, the refractive index at a wavelength of 550 nm of the entire internal light extraction layer was measured using a sopra ellipsometer, and it was 1.85.

  Next, the substrate formed up to the smooth layer was fixed to a holder of a commercially available vacuum deposition apparatus. Moreover, the example compound (1-6) of the base layer mentioned above was put into the resistance heating boat made from tantalum, and this resistance heating boat was attached in the 1st vacuum chamber of a vacuum evaporation system with the holder to which the board | substrate was fixed. Furthermore, silver (Ag) was put into a resistance heating boat made of tungsten, and attached to the second vacuum chamber of the vacuum evaporation apparatus.

After depressurizing the first vacuum tank to 4 × 10 ⁻⁴ Pa, the resistance heating boat containing the exemplified compound (1-6) is heated by energization, and the exemplified compound (1-6) is evaporated on the substrate to be transparent. An underlayer for the electrode was formed. The deposition rate was in the range of 0.1 to 0.2 nm / second. A mask is used at the time of vapor deposition, as shown in FIG. 6, a 4.0 cm × 4.0 cm region at the center of the same substrate as the region where the light scattering layer is formed, and from the region to the R side in the LR direction. An underlayer was formed on the exposed area of 4.0 cm × 0.6 cm. The layer thickness of the underlayer was 50 nm.

The substrate on which the underlayer was formed was transferred to the second vacuum chamber under vacuum pressure, and the second vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa. After depressurization, a resistance heating boat containing silver was energized and heated, and silver was deposited on the substrate to form an electrode layer of a transparent electrode. The deposition rate was in the range of 0.1 to 0.2 nm / second. As shown in FIG. 6, a 4.0 cm × 3.6 cm region that overlaps the 4.0 cm × 4.0 cm region at the center of the substrate and a 4.0 cm exposed to the R side from the region are used by using a mask. An electrode layer composed of a region of × 0.6 cm was formed. The layer thickness of the electrode layer was 8 nm.

  When the electrode layer is formed, the following compounds α-NPD, BD-1, GD-1, RD-1, H-1, Filled with H-2 and E-1. The evaporation crucible used was made of a resistance heating material such as molybdenum or tungsten.

After reducing the pressure in the reaction chamber to a vacuum pressure of 1 × 10 ⁻⁴ Pa, the deposition crucible filled with the compound α-NPD was energized and heated, and the compound α-NPD was added to the substrate at 0.1 nm / second. The hole injecting and transporting layer was formed by vapor deposition at a vapor deposition rate of The layer thickness of the hole injecting and transporting layer was 40 nm.
Similarly, the compounds BD-1 and H-1 are co-evaporated at a deposition rate of 0.1 nm / second so that the concentration of the compound BD-1 is 5%, and a fluorescent light-emitting layer exhibiting a blue color with a layer thickness of 15 nm Formed.

Subsequently, the deposition rate of 0.1 nm / second was applied to the compounds GD-1, RD-1, and H-2 so that the concentration of the compound GD-1 was 17% and the concentration of the compound RD-1 was 0.8%. To form a phosphorescent light emitting layer exhibiting a yellow color with a layer thickness of 15 nm.
Further, Compound E-1 was deposited at a deposition rate of 0.1 nm / second to form an electron transport layer having a layer thickness of 30 nm.
In addition, each layer was formed in the area | region of 4.0 cm x 4.0 cm of the center of a board | substrate using the mask at the time of vapor deposition of each layer of an organic functional layer.

A lithium fluoride (LiF) layer having a layer thickness of 1.5 nm is formed on the organic functional layer, and aluminum is further deposited to stack an aluminum layer having a layer thickness of 110 nm. ) And a transparent electrode lead-out wiring. A mask corresponding to each pattern was used for forming the cathode and the lead-out wiring.
As shown in FIG. 6, the lead-out wiring was formed in a 4.0 cm × 0.2 cm region overlapping the electrode layer region of the transparent electrode and a 4.0 cm × 0.3 cm region exposed to the R side from the region. . The cathode has a 3.2 cm × 3.6 cm region that overlaps the 4.0 cm × 4.0 cm region in the center of the substrate, and a 3.2 cm × 1.3 cm region exposed from this region to the L side opposite to the lead-out wiring. Formed in the region.

Thereafter, a sealing material was bonded via an adhesive so as to cover each layer on the substrate, and then heat-treated at 120 ° C. for 10 minutes for solid sealing.
As the sealing material, a highly flexible sealing material in which a polyethylene terephthalate (PET) film having a thickness of 12 μm was bonded to an aluminum foil having a thickness of 30 μm (manufactured by Toyo Aluminum Co., Ltd.) was used. For bonding the PET film, a two-component reaction type urethane adhesive for dry lamination was used, and the layer thickness of the adhesive was 1.5 μm.

Specifically, a thermosetting adhesive was uniformly applied to the surface of the aluminum foil of the sealing material so as to have a thickness of 20 μm using a vacuum laminator. A dispenser was used for application. Then, the surface on which the thermosetting adhesive was applied and the surface on which each layer of the substrate was formed were bonded together, and dried for 12 hours under a vacuum pressure of 100 Pa or less. Further, the substrate was moved to a nitrogen atmosphere having a dew point temperature of −80 ° C. or lower and an oxygen concentration of 0.8 ppm and dried for 12 hours or more, and the moisture content of the thermosetting adhesive was adjusted to 100 ppm or lower.
As the thermosetting adhesive, an epoxy adhesive mixed with the following (A) to (C) was used.
(A) Bisphenol A diglycidyl ether (DGEBA)
(B) Dicyandiamide (DICY)
(C) Epoxy adduct curing accelerator

After sealing, a microlens array sheet (manufactured by MNtech) was attached as an external light extraction layer to the surface opposite to the surface on which each layer of the substrate was formed, and the organic EL element 101 was obtained.
In the organic EL element 101, light of each color obtained from the light emitting layer during light emission can be extracted from the substrate side. As shown in FIG. 6, a 3.2 cm × 3.2 cm region (a hatched region in FIG. 6) in the center of the substrate where the pair of electrodes and the light emitting layer overlap is a light emitting region, and the width around the light emitting region A 1.4 cm region is a non-light emitting region.

[Organic EL element 102]
In the manufacture of the organic EL element 101, the one end of the smoothing layer on the lead-out wiring side (R side in FIG. 6) is smaller than the one end of the light-scattering layer on the lead-out wiring side. An organic EL element 102 was produced in the same manner as the organic EL element 101 except that the region where the light scattering layer was formed by shortening one end was set to 4.0 cm × 3.8 cm.

[Organic EL element 103]
In the manufacture of the organic EL element 101, the smooth layer is exposed to the 4.0 cm × 4.0 cm region at the center of the substrate and the lead wiring side (R side in FIG. 6) from the region to 4.0 cm × 0.6 cm. The organic EL element 103 was manufactured in the same manner as the organic EL element 101 except that the organic EL element 101 was formed.

[Organic EL element 104]
In the manufacture of the organic EL element 103, the light scattering layer is exposed to the 4.0 cm × 4.0 cm region at the center of the substrate and the 4.0 cm × 0.00 mm exposed from the region to the lead-out wiring side (R side in FIG. 6). An organic EL element 104 was produced in the same manner as the organic EL element 103 except that it was formed in a 6 cm region.

[Organic EL element 201]
In the production of the organic EL element 101, an organic EL element 201 was produced in the same manner as the organic EL element 101, except that the base layer was formed only in a 4.0 cm × 4.0 cm region at the center of the substrate.

[Organic EL element 202]
In the manufacture of the organic EL element 102, the light scattering layer is exposed to the 4.0 cm × 4.0 cm region at the center of the substrate and the 4.0 cm × 0. An organic EL element 202 was manufactured in the same manner as the organic EL element 102 except that it was formed in a 2 cm region.
That is, in the organic EL element 202, one end of the light scattering layer on the lead-out wiring side is positioned on the lead-out wiring side from one end of the smoothing layer on the lead-out wiring side.

[Evaluation]
Ten organic EL elements 101 to 104, 201, and 202 were manufactured, and a voltage of 10 V was applied to each. Of the ten, the ratio (%) of the number of organic EL elements that did not emit light when a voltage was applied and did not emit light was determined as the ratio at which the wire portion of the electrode layer of the transparent electrode was broken.
In addition, the organic EL element that emitted light by applying voltage was wound around a cylinder having a diameter of 2 cm with the light extraction side as the outside, bent, and then removed from the cylinder, and a voltage of 10 V was applied again to emit organic light. The number of EL elements was determined. Of the 10 elements, the ratio (%) of the total number of the number of organic EL elements that did not emit light before bending and the number of organic EL elements that emitted light before bending but did not emit light after bending was expressed as It calculated | required as a ratio (%) of disconnection.

Table 1 below shows the evaluation results.

  As can be seen from Table 1, as compared with the organic EL elements 201 and 202, the organic EL elements 101 to 104 according to the present invention have fewer disconnections regardless of before and after bending. In particular, it can be seen that the organic EL elements 103 to 104 are not disconnected, and the conductive portions of the electrode layers are continuously formed to such an extent that they can withstand the disconnection when bent.

  INDUSTRIAL APPLICATION This invention can be utilized for the use of the disconnection prevention of the conducting wire part of the electrode layer provided in order to connect the electrode of an organic EL element to the exterior.

DESCRIPTION OF SYMBOLS 10 Organic EL element 1 Board | substrate 2A Internal light extraction layer 21 Light scattering layer 22 Smooth layer 2B External light extraction layer E1 Transparent electrode Ea Electrode layer a1 Main-body part a2 Conductor part Eb Ground layer E2 Electrode 3c Light emitting layer 5 Lead-out wiring

Claims (8)

An organic electroluminescence device comprising a pair of electrodes on a substrate and a light emitting layer disposed between the pair of electrodes,
Of the pair of electrodes, a transparent electrode disposed on the substrate side;
A light scattering layer located between the substrate and the transparent electrode;
A lead wiring for connecting the transparent electrode to an external power source,
The transparent electrode comprises an underlayer containing a compound containing a nitrogen atom or a sulfur atom, and an electrode layer formed on the underlayer using silver or a silver alloy, or copper or a copper alloy,
The electrode layer includes a main body portion formed so as to overlap a region of the light emitting layer, and a conductive wire portion exposed from the main body portion to the lead-out wiring side,
The lead-out wiring is formed so as to overlap at least a part of the conductor portion;
The organic electroluminescence element, wherein the underlayer is formed under both the main body portion and the conductor portion of the electrode layer. Further comprising a smooth layer positioned between the light scattering layer and the underlayer,
The smoothing layer is formed such that one end of the smoothing layer on the lead-out wiring side is positioned closer to the lead-out wiring side than one end of the light scattering layer on the lead-out wiring side. 2. The organic electroluminescence device according to 1.   The organic electroluminescence device according to claim 2, wherein the smooth layer is formed under both the main body portion and the conductor portion of the electrode layer.   4. The organic electroluminescence device according to claim 3, wherein the light scattering layer is formed below both the main body portion and the conductor portion of the electrode layer. A method for producing an organic electroluminescent device comprising a transparent electrode provided with an electrode layer on a substrate, an electrode paired with the transparent electrode, and a light emitting layer disposed between the pair of electrodes,
(A) forming a light scattering layer on the substrate;
(B) forming an underlayer of the electrode layer on the light scattering layer, the underlayer containing a compound containing a nitrogen atom or a sulfur atom;
(C) On the underlayer, using silver or a silver alloy, or copper or a copper alloy, a main body portion of the electrode layer is formed so as to overlap with the region of the light emitting layer, and exposed from the main body portion. Forming a conductive wire portion of the electrode layer;
(D) forming a lead-out line for connecting the transparent electrode to an external power source so as to overlap at least a part of the conductor portion;
In the step (b), the base layer is formed in both the region where the main body portion of the electrode layer is formed and the region where the conductive wire portion is formed. (E) further comprising a step of forming a smooth layer between the light scattering layer and the underlayer;
In the step (e), the smoothing layer is formed such that one end of the smoothing layer on the lead-out wiring side is positioned on the lead-out wiring side than one end of the light scattering layer on the lead-out wiring side. The manufacturing method of the organic electroluminescent element of Claim 5 characterized by the above-mentioned.   The organic electro according to claim 6, wherein in the step (e), the smooth layer is formed in any of a region where a main body portion of the electrode layer is formed and a region where a conductive wire portion is formed. Manufacturing method of luminescence element.   8. The organic material according to claim 7, wherein in the step (a), the light scattering layer is formed in any of a region where a main body portion of the electrode layer is formed and a region where a conductive wire portion is formed. Manufacturing method of electroluminescent element.

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