JP2013045751A - Organic electroluminescent element and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly bright organic EL element suppressed in deterioration of a conductive reflection film due to heat and light during light emission thereof, suppressed in deterioration of light emission intensity due to peeling of the conductive reflection film from a luminous layer or the like, and improved in durability.SOLUTION: An organic electroluminescent element includes a base material, a transparent electrode layer, a luminous layer and a conductive reflection film, in this order. The conductive reflection film contains a metal nanoparticle sintered body and an additive.

Description

  The present invention relates to an organic electroluminescence element (hereinafter referred to as an organic EL element) and a method for producing the same. More specifically, the present invention relates to an organic EL element including a conductive reflective film that is formed on a substrate and can efficiently extract light from an organic EL light emitting layer, and a method for manufacturing the same.

  2. Description of the Related Art In recent years, organic EL elements have begun to be used in various fields with improvements in luminous efficiency and durability. In particular, application development for use in lighting fixtures and displays is rapidly progressing.

  FIG. 1 shows an example of a cross-sectional structure of an organic EL element. As shown in FIG. 1, the organic EL element 1 is a multilayer in which a light emitting layer 40 made of an organic material is sandwiched between a pair of conductive reflective films 10 (cathode) and a transparent electrode layer 30 (anode) on a base material 20. Composed of structure. As described above, in the organic EL element, a transparent electrode layer is used as an electrode layer for extracting light, and a conductive reflection film as an electrode layer having a reflection function is provided for an electrode layer that does not extract light. A structure that increases the emission intensity by efficiently reflecting the light from the light emitting layer is used.

  In general, the conductive reflective film is formed by a vacuum film formation method such as sputtering or vacuum deposition. However, the vacuum film formation method requires a large cost because it maintains and operates a large vacuum film formation apparatus. To do. Replacing this vacuum film-forming method with a wet coating method is expected to greatly improve running costs.

  As this wet coating method, a method of forming a cathode of an organic EL element by applying a dispersion liquid in which metal particles having an average particle diameter of 1 to 20 nm are dispersed is disclosed (Patent Document 1).

JP 2010-198935 A

  However, when the conductive reflective film is formed by the method of applying the dispersion, the conductive reflective film deteriorates and peels off from the light emitting layer due to heat and light during light emission of the organic EL element, and the organic EL element emits light. There is a problem of durability that strength decreases. More specifically, the conductive reflective film is formed by applying a conductive reflective film composition containing metal particles and then firing, and metal nanoparticles are used as the metal particles in order to perform this firing at a low temperature. . Here, in the above method, in order to avoid sintering between the metal nanoparticles during storage, the metal nanoparticles are coated with a primary amine or a derivative thereof that evaporates or decomposes at around 200 ° C. However, when this primary amine or the like is added, the metal nanoparticles are excessively grown during sintering and become porous, so that the adhesion of the conductive reflective film is reduced, and the conductive reflective film is removed from the light emitting layer and the like. There exists a problem that it peels, a reflection characteristic falls, and the brightness | luminance of an organic EL element also falls. In addition, in order to suppress the growth of metal nanoparticles, excessive addition of primary amine or the like, the dispersion stability of the metal nanoparticles will be reduced or the resulting film will have poor reflective properties and conductivity The organic EL element has a problem. Since the current flowing per unit volume is larger than that of a light emitter such as an LED, the conductive reflective film of the organic EL element has conductivity in other light emitters. Since the conductive film has higher conductivity than the reflective film, that is, the conductive reflective film is required to have a thickness, it is easy to peel off due to the difference in thermal expansion coefficient from other layers.

  An object of the present invention is to solve the above problems. That is, it is an organic EL element with high brightness, which suppresses deterioration of the conductive reflective film due to heat and light during light emission of the organic EL element, and suppresses a decrease in light emission intensity due to peeling of the conductive reflective film from the light emitting layer or the like. And it aims at obtaining the organic EL element which durability improved.

The present invention relates to an organic EL element that solves the above-described problems with the following configuration, and a method for manufacturing the same.
(1) An organic EL element comprising a substrate, a transparent electrode layer, a light emitting layer, and a conductive reflective film in this order, wherein the conductive reflective film comprises a metal nanoparticle sintered body and an additive. An organic EL element containing the organic EL element.
(2) A transparent electrode layer and a light emitting layer are formed on a substrate in this order, and then a conductive reflective film composition containing metal nanoparticles and additives is formed on the light emitting layer by a wet coating method. A method for producing an organic EL device, comprising: applying a conductive film; and baking the conductive reflective film to form a light emitting layer and a transparent electrode layer on the conductive reflective film.

  According to the present invention (1), since the additive contained in the conductive reflective film suppresses the growth of metal nanoparticles during sintering, the reflective characteristic of the conductive reflective film is improved, and the organic EL element The brightness becomes higher. In addition, the presence of an additive in the conductive reflective film suppresses deterioration of the conductive reflective film due to heat and light during light emission of the organic EL element, and improves the adhesion of the conductive reflective film. It is possible to obtain an organic EL element with improved durability by suppressing a decrease in light emission intensity due to peeling of the conductive reflective film from the layer or the like. According to the present invention (2), it is possible to easily produce an organic EL element having high luminance and improved durability.

It is an example of the cross-sectional structure of an organic EL element.

  Hereinafter, the present invention will be specifically described based on embodiments. Unless otherwise indicated, “%” means “% by mass” unless otherwise specified.

[Organic EL device]
The organic EL device of the present invention is an organic EL device comprising a substrate, a conductive reflective film, a light emitting layer, and a transparent electrode layer in this order, and the conductive reflective film is a metal nanoparticle sintered body. And an additive. In FIG. 1, an example of the cross-sectional structure of the organic EL element 1 provided with the base material 20, the transparent electrode layer 30, the light emitting layer 40, and the electroconductive reflection film 10 in this order is shown.

  Conventionally, metals having a low work function such as Mg, Ca, Sn, Pb, Li, Mn, and Al or alloys thereof are used for the cathode in order to facilitate electron injection into the organic light emitting layer. In the present invention, the metal nanoparticle sintered body imparts the reflectivity of light emitted from the light emitting layer and conductivity to the conductive reflective film. As a metal nanoparticle used for the composition for conductive reflective films, one kind selected from the group consisting of silver, gold, platinum, copper, palladium, ruthenium, magnesium, nickel, tin, indium, gallium and copper, or Two or more kinds of mixed compositions or alloy compositions may be mentioned, and silver is preferable from the viewpoints of reflectivity and conductivity, and it is preferable to use magnesium and tin having a low work function in combination. The average particle diameter of the metal nanoparticles is preferably 10 to 50 nm. Here, an average particle diameter is measured using the dynamic light-scattering method by Horiba LB-550. The shape of the metal nanoparticles is preferably spherical or plate-like from the viewpoints of dispersibility and reflectivity.

  The additive is present in the conductive reflective film after sintering, and the presence of the additive between the metal nanoparticles can suppress the particle growth of the metal nanoparticles during sintering. The presence of additives in the pores of the particle sintered body improves the reflection characteristics of the conductive reflective film, increases the brightness of the organic EL element, and improves the heat resistance, light resistance and corrosion resistance of the conductive reflective film. Let Furthermore, the adhesiveness of the conductive reflective film is improved by the additive. Therefore, the durability of the organic EL element is increased.

  Examples of the additive include organic polymers, metal oxides, metal hydroxides, organometallic compounds, and silicone oils. Organic polymers are preferable, organic polymers, metal hydroxides or organometallic compounds, It is more preferable to use in combination.

  The organic polymer used as the additive is at least one selected from the group consisting of polyvinyl pyrrolidone (PVP), a polyvinyl pyrrolidone copolymer, and water-soluble cellulose. From the viewpoint of sex. Examples of the polyvinylpyrrolidone copolymer include a PVP-methacrylate copolymer, a PVP-styrene copolymer, and a PVP-vinyl acetate copolymer. Examples of the water-soluble cellulose include cellulose ethers such as hydroxypropyl methylcellulose, methylcellulose, and hydroxyethylmethylcellulose. PVP is more preferable from the viewpoint of the reflection characteristics, conductivity and adhesion of the conductive reflective film.

  Examples of the metal oxide used as the additive include an oxide or composite oxide containing at least one selected from the group consisting of tin, indium, zinc, and antimony, and tin-doped indium oxide and zinc oxide are preferable.

  Examples of the metal hydroxide used as an additive include hydroxides such as magnesium, lithium, aluminum, iron, cobalt, nickel, and lithium hydroxide is preferable.

  Examples of the organometallic compound used as the additive include metal soaps such as silicon, titanium, zirconium, zinc, copper, and tin, metal complexes, metal alkoxides, and hydrolysates of metal alkoxides. For example, examples of the metal soap include zinc acetate, zinc oxalate, copper acetate, tin acetate, and iron citrate, examples of the metal complex include acetylacetone zinc complex, and examples of the metal alkoxide include titanium isopropoxide. And methyl silicate. From the viewpoint of adhesion of the conductive reflective film, zinc acetate, copper acetate, iron citrate, and titanium isopropoxide are preferable.

  Examples of the silicone oil used as an additive include straight silicone oil and modified silicone oil, and modified silicone oil is preferable.

  The thickness of the conductive reflective film is preferably 0.1 to 3.0 μm from the viewpoints of reflectivity and conductivity.

Further, when the pores present on the light emitting layer side surface of the conductive reflective film have an average diameter of 100 nm or less, an average depth of 100 nm or less, and a number density of 30 / μm ² , the wavelength: 380 to 780 nm In this range, a high diffuse reflectance of 80% or more of the theoretical reflectance can be achieved, which is preferable.

  The base material, the light emitting layer, and the transparent electrode layer constituting the organic EL element may be known to those skilled in the art and are not particularly limited. For example, a glass substrate is used as the base material, tris (8-quinolinolato) aluminum doped with 5% by weight of rubrene is used as the light emitting layer, and ITO is used as the transparent electrode layer.

[Method for producing organic EL element]
In the method for producing an organic EL device of the present invention, a transparent electrode layer and a light emitting layer are formed on a substrate in this order, and then a conductive reflective film containing metal nanoparticles and an additive on the light emitting layer. The composition is applied by a wet coating method and then baked to form a conductive reflective film.

<< Formation of transparent electrode layer and light emitting layer >>
The method for forming the transparent electrode layer and the light emitting layer on the substrate is not particularly limited, and may be a method known to those skilled in the art, such as a vacuum film forming method. The transparent electrode layer is, for example, a transparent binder and a transparent material. It is more preferable to form a film by a wet coating method using a composition containing a conductive material.

<< Composition for conductive reflective film >>
The metal nanoparticles and additives contained in the composition for conductive reflective film are as described above.

  Moreover, the composition for electroconductive reflective film contains a dispersion medium, and the dispersion medium is a solvent compatible with 1% by mass or more of water and 2% by mass or more of water with respect to 100% by mass of all the dispersion media. For example, it is preferable to contain alcohols. For example, when the dispersion medium is composed of only water and alcohols, it contains 98% by mass of alcohol when it contains 2% by mass of water, and 98% by mass of water when it contains 2% by mass of alcohol. When the water content is less than 1% by mass or the alcohol content is less than 2% by mass, it is difficult to sinter the film obtained by applying the conductive reflective film composition by a wet coating method at a low temperature. Moreover, it is because the electroconductivity and reflectivity of the electroconductive reflective film after firing are reduced. Examples of alcohols include methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol, diethylene glycol, glycerol, erythritol, and the like.

  Furthermore, when the dispersion medium contains a protective agent containing either one or both of a hydroxyl group (—OH) and a carbonyl group (—C═O) that chemically modify the surface of the metal nanoparticles, the composition for a conductive reflective film It is suitable because it has excellent dispersion stability and has an effective action for low-temperature sintering of the coating film. Examples of the protective agent include sodium citrate and sodium malate.

  The composition for conductive reflective film is a range that does not impair the object of the present invention, and further, if necessary, a low resistance agent, a water-soluble cellulose derivative, an antioxidant, a leveling agent, a thixotropic agent, a filler, A stress relaxation agent, other additives, etc. can be mix | blended.

  From the viewpoint of reflectivity and conductivity, the metal nanoparticles are preferably 75 parts by mass or more with respect to 100 parts by mass of the composition for conductive reflective film excluding the dispersion medium. Moreover, it is preferable from the viewpoint of the adhesiveness of a conductive reflective film that it is 99.9 mass parts or less.

  The content of the additive is preferably 0.1 to 25 parts by mass with respect to 100 parts by mass of the conductive reflective film composition excluding the dispersion medium. If it is 0.1 part by mass or more, the base material and the adhesive force are good, and if it is 25 parts by mass or less, film unevenness during film formation hardly occurs.

  The dispersion medium is preferably 50 to 99 parts by mass with respect to 100 parts by mass of the conductive reflective film composition from the viewpoint of coatability.

  The conductive reflective film composition is prepared by mixing desired components by a paint shaker, a ball mill, a sand mill, a centrimill, a three roll, etc., in a conventional manner, and dispersing a translucent binder, and optionally transparent conductive particles. Can be produced. Of course, it can also be produced by a normal stirring operation. In addition, after mixing the component except a metal nanoparticle, when it mixes with the dispersion medium containing the metal nanoparticle separately disperse | distributed previously beforehand, it is preferable from a viewpoint of obtaining the homogeneous composition for electroconductive reflective films easily.

<Formation of conductive reflective film>
First, the conductive reflective film composition is applied onto a substrate by a wet coating method. The application here is performed so that the thickness of the conductive reflective film after firing is preferably 0.1 to 3.0 μm. Subsequently, the conductive reflective coating film is preferably dried at a temperature of 120 to 350 ° C. for 5 to 60 minutes. In this way, a coating film is formed.

  The wet coating method is preferably a spray coating method, a dispenser coating method, a spin coating method, a knife coating method, a slit coating method, an inkjet coating method, a screen printing method, an offset printing method, or a die coating method. However, the present invention is not limited to this, and any method can be used.

  Next, the base material having the conductive reflective coating film is fired in the air or in an inert gas atmosphere such as nitrogen or argon, preferably at a temperature of 130 to 250 ° C. for 5 to 60 minutes.

  The reason why the firing temperature of the substrate having the coating film is preferably in the range of 130 to 250 ° C. is that if it is less than 130 ° C., the conductive reflective film has a problem of insufficient curing. On the other hand, if it exceeds 250 ° C., the production merit of the low temperature process cannot be utilized, that is, the manufacturing cost increases and the productivity decreases. Furthermore, when using a flexible substrate such as a resin film, a firing temperature of less than 200 ° C. is preferred. That is, if the baking temperature after wet coating is low, a flexible substrate such as a resin film can be used as the base material of the organic EL element, in addition to the glass substrate, and thus the application range is expanded.

  The reason why the firing time of the substrate having the coating film is preferably in the range of 5 to 60 minutes is that if the firing time is less than 5 minutes, there is a problem that firing is not sufficient in the conductive reflective film. This is because if the firing time exceeds 60 minutes, the manufacturing cost increases more than necessary and the productivity is lowered.

  As described above, the manufacturing method of the present invention can eliminate a vacuum film forming method such as sputtering or vacuum deposition as much as possible by using a wet coating method, and therefore can manufacture a conductive reflective film at a lower cost. The organic EL element with improved durability can be easily produced at low cost.

  Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited thereto.

[Example 1]
<< Preparation of composition for conductive reflective film >>
First, a composition for conductive reflective film was prepared. The production procedure is shown below.

  Silver nitrate was dissolved in deionized water to prepare an aqueous metal salt solution. In addition, sodium citrate was dissolved in deionized water to prepare a sodium citrate aqueous solution having a concentration of 26% by mass. In this sodium citrate aqueous solution, granular ferrous sulfate is directly added and dissolved in a nitrogen gas stream maintained at 35 ° C., and citrate ions and ferrous ions are contained in a molar ratio of 3: 2. A reducing agent aqueous solution was prepared.

  Next, a magnetic stirrer stirrer is placed in the reducing agent aqueous solution while maintaining the nitrogen gas flow at 35 ° C., and the reducing agent aqueous solution is stirred at a rotating speed of the stirrer: 100 rpm. An aqueous salt solution was added dropwise and mixed. Here, the concentration of each solution is adjusted so that the amount of the metal salt aqueous solution added to the reducing agent aqueous solution is 1/10 or less of the amount of the reducing agent aqueous solution. The reaction temperature was kept at 40 ° C. The mixing ratio of the reducing agent aqueous solution and the metal salt aqueous solution is such that the molar ratio of citrate ions and ferrous ions in the reducing agent aqueous solution to the total valence of metal ions in the metal salt aqueous solution is 3 The moles were doubled. After the addition of the aqueous metal salt solution to the reducing agent aqueous solution is completed, the mixture is further stirred for 15 minutes to generate silver nanoparticles inside the mixture, and the silver nanoparticle dispersion in which the silver nanoparticles are dispersed Got. The pH of the silver nanoparticle dispersion was 5.5, and the stoichiometric amount of silver nanoparticles in the dispersion was 5 g / liter.

  The obtained silver nanoparticle dispersion was allowed to stand at room temperature, so that the silver nanoparticles in the dispersion were allowed to settle, and aggregates of the precipitated silver nanoparticles were separated by decantation. Deionized water was added to the separated silver nanoparticle aggregates to form a dispersion, and after desalting by ultrafiltration, the metal (silver) content was adjusted to 50% by mass by washing with methanol. . Thereafter, using a centrifuge, the centrifugal force of the centrifuge was adjusted to separate relatively large silver particles having a particle size exceeding 100 nm, thereby obtaining a silver nanoparticle dispersion. As a result of measuring the average particle diameter of the silver nanoparticles using a dynamic light scattering method using LB-550 manufactured by Horiba, the average particle diameter was 35 nm. The obtained silver nanoparticles were chemically modified with a protective agent for sodium citrate.

  Next, 10 parts by mass of the obtained metal nanoparticles were dispersed by adding and mixing in 90 parts by mass of a mixed solution containing water, ethanol and methanol, and polyvinyl pyrrolidone (PVP, molecular weight: 360,000) was dispersed in this dispersion. ) Was added so that the ratio of metal nanoparticles: 96 parts by mass and PVP: 4 parts by mass was prepared.

<< Manufacture of organic EL elements >>
An ITO ink was applied to a glass substrate and baked at 175 ° C. for 30 minutes to form a transparent electrode layer (anode, thickness: 150 nm). On top of that, a hole transport layer (N, N′-diphenyl-N, N′-di (m-tolyl) benzidine, thickness: 30 nm), a light emitting layer (tris (8-quinolinolato) aluminum doped with 5% by weight of rubrene) , Thickness: 30 nm), and an electron transport layer (tris (8-quinolinolato) aluminum, thickness: 30 nm) were sequentially formed, and then the conductive reflective film composition was formed several times by spin coating at 1000 rpm × 60 seconds. The film was formed, and then baked at 180 ° C. for 60 minutes to form a conductive reflective film (cathode) having a film thickness of about 300 nm, thereby obtaining an organic EL element. Here, the film thickness was measured by cross-sectional observation using a scanning electron microscope (SEM, device names: S-4300, SU-8000) manufactured by Hitachi High-Technologies. In other examples and comparative examples, the film thickness was measured in the same manner.

The obtained organic EL device was evaluated for luminance, adhesion, and durability. The luminance was measured with a luminance meter (model number: BM-9, manufactured by Topcon Corporation). Adhesion was performed by a method according to a tape peel test (JIS K-5600-5-6). The case where there was no peeling was “◯”, and the case where there was peeling was “x”. For durability, the time until the luminance became 500 cd / cm ² or less was measured.

[Examples 2 to 7]
A conductive reflective film was formed in the same manner as in Example 1 except that the composition described in Table 1 was used, and an organic EL element was obtained.

[Comparative Example 1]
An organic EL device was obtained in the same manner as in Example 1 except that a composition for conductive reflective film was prepared using a silver nanoparticle dispersion liquid to which no additive was added, and a conductive reflective film was formed.

[Comparative Example 2]
An organic EL element was obtained in the same manner as in Example 1 except that a silver electrode was formed by sputtering as the conductive reflective film.

  As is clear from Table 1, Examples 1 to 7 have a high reflective property of the conductive reflective film as in Comparative Example 2 in which the conductive reflective film is formed by sputtering. The adhesiveness of the conductive reflective film was high, and the durability of the organic EL element was higher than that of Comparative Example 2. In particular, Examples 3 and 7 using Mg having a low work function as a part of a metal material and using metal alkoxide or zinc acetate having good adhesion as an additive have high luminance and durability of the organic EL device. It was. On the other hand, in Comparative Example 1 in which the conductive reflective film was prepared by applying the metal nanoparticle dispersion without additives, the initial luminance of the organic EL element was low because the reflective characteristics of the conductive reflective film were poor. As a result, the adhesion of the conductive reflective film was poor, and the durability of the organic EL element was very low.

  The organic EL device of the present invention can have high durability by including a conductive reflective film including a metal nanoparticle sintered body and an additive, and can be electrically conductive by heat generated from the organic EL device or by the environment. Deterioration of the reflective film can be suppressed, which is very useful. Since this conductive reflective film can be produced by a wet coating method, the manufacturing process can be simplified and the cost can be reduced.

DESCRIPTION OF SYMBOLS 1 Organic EL element 10 Conductive reflective film 20 Base material 30 Transparent electrode layer 40 Light emitting layer 50 Sealing material

Conventionally, metals having a low work function such as Mg, Ca, Sn, Pb, Li, Mn, and Al or alloys thereof are used for the cathode in order to facilitate electron injection into the organic light emitting layer. In the present invention, the metal nanoparticle sintered body imparts the reflectivity of light emitted from the light emitting layer and conductivity to the conductive reflective film. The metal nanoparticles used in the electrically conductive reflective film composition, silver, gold, platinum, palladium, ruthenium, magnesium, nickel, tin, indium, one selected from the group consisting of gallium and copper or 2, A mixed composition or alloy composition of more than one species can be mentioned, and silver is preferable from the viewpoints of reflectivity and conductivity, and further, magnesium and tin having a low work function are preferably used in combination. The average particle diameter of the metal nanoparticles is preferably 10 to 50 nm. Here, an average particle diameter is measured using the dynamic light-scattering method by Horiba LB-550. The shape of the metal nanoparticles is preferably spherical or plate-like from the viewpoints of dispersibility and reflectivity.

The additive is present in the conductive reflective film after sintering, and the presence of the additive between the metal nanoparticles can suppress the particle growth of the metal nanoparticles during sintering. The presence of additives in the pores of the particle sintered body improves the reflection characteristics of the conductive reflective film, increases the brightness of the organic EL element, and improves the heat resistance, light resistance and corrosion resistance of the conductive reflective film. Let Further, the additives, adhesion of the conductive reflective film is improved. Therefore, the durability of the organic EL element is increased.

Conductive reflective film composition, within a range not to impair the purpose of the present invention, if necessary, a low-resistance agent, a water-soluble cellulose derivatives, antioxidants, leveling agents, thixotropic, filler, stress relaxation Agents, other additives, etc. can be blended.

<Formation of conductive reflective film>
First, the conductive reflective film composition is applied onto the light emitting layer by a wet coating method. The application here is performed so that the thickness of the conductive reflective film after firing is preferably 0.1 to 3.0 μm. Subsequently, the conductive reflective coating film is preferably dried at a temperature of 120 to 350 ° C. for 5 to 60 minutes. In this way, a coating film is formed.

The reason why the firing temperature of the substrate having the coating film is preferably in the range of 130 to 250 ° C. is that if it is less than 130 ° C., the conductive reflective film has a problem of insufficient curing. On the other hand, if it exceeds 250 ° C., the production merit of the low temperature process cannot be utilized, that is, the manufacturing cost increases and the productivity decreases. Furthermore, when using a flexible substrate such as a resin film, a firing temperature of less than 200 ° C. is preferred. That is, if the baking temperature after wet coating is low, a flexible substrate such as a resin film can be used as the base material of the organic EL element, in addition to the glass substrate, and thus the application range is expanded.

The reason why the firing time of the substrate having the coating film is preferably in the range of 5 to 60 minutes is that when the firing time is less than 5 minutes, the conductive reflective film has a problem of insufficient firing. This is because if the firing time exceeds 60 minutes, the manufacturing cost increases more than necessary and the productivity is lowered.

Claims (2)

  An organic electroluminescence device comprising a base material, a transparent electrode layer, a light emitting layer, and a conductive reflective film in this order, wherein the conductive reflective film contains a metal nanoparticle sintered body and an additive. An organic electroluminescence device characterized by that. After forming the transparent electrode layer and the light emitting layer in this order on the substrate, the conductive reflective film composition containing the metal nanoparticles and the additive was applied on the light emitting layer by a wet coating method. Then, a conductive reflective film is formed by baking, and the manufacturing method of an organic electroluminescent element characterized by the above-mentioned.