JP2013161673A - Manufacturing method of organic el element and organic el element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of an organic EL element capable of achieving an organic EL panel of top emission type while increasing the electron injection efficiency.SOLUTION: The manufacturing method of an organic EL element comprises the steps of: forming an anode 12 over a substrate 11; forming an organic light-emitting layer 16 above the anode 12; forming an electron injecting transportation layer 17' containing a first material of at least one of an alkali metal compound and an alkaline earth metal compound; a second material of a metal having reducing property on the alkali metal or alkaline earth metal constituting the first material; and a third material having electron transportation property above the organic light-emitting layer 16; giving light permeability to the second material by transforming at least a part of the metal having the reducing property in the electron injecting transportation layer 17'; and forming a cathode 18 having the light permeability over the electron injecting transportation layer 17 during or after the step of giving the light permeability.

Description

  The present invention relates to a method for manufacturing an organic EL element, and an organic EL element.

In recent years, organic EL panels in which organic EL elements are arranged on a substrate are becoming widespread. The organic EL panel is characterized by high visibility because it uses an organic EL element that emits light, and has excellent impact resistance because it is a complete solid element.
An organic EL element is a current-driven light-emitting element, and is configured by laminating an organic light-emitting layer that performs electroluminescence phenomenon by recombination of electrons and holes, which are carriers, between electrode pairs composed of an anode and a cathode. The In such an organic EL element, there is one provided with an electron injection layer having a function of promoting electron injection from the cathode to the organic light emitting layer between the cathode and the organic light emitting layer (for example, Patent Documents 1 and 2). .

  FIG. 15 is a cross-sectional view schematically showing the structure of the organic EL element 90 according to Patent Documents 1 and 2. The organic EL element 90 is manufactured through a process of sequentially forming an anode 91 made of a transparent electrode material, a hole transport layer 92, an organic light emitting layer 93, an electron injection layer 94, and a cathode 95. The hole transport layer 92 has a function of promoting the transport of holes from the anode 91 to the organic light emitting layer 93.

  For the electron injection layer 94 according to Patent Document 1, an organometallic complex compound containing at least one of alkali metal ions, alkaline earth metal ions, and rare earth metal ions is used. For the electron injection layer 94 according to Patent Document 2, a mixture of the organometallic complex compound and the electron transporting organic material is used. Further, the cathode 95 is made of a metal capable of reducing each metal ion in vacuum, for example, a cathode material such as aluminum or titanium. Then, by forming the cathode material on the electron injection layer 94 in the step of forming the cathode 95, the respective metals contained in the organometallic complex compound of the electron injection layer 94 are dissociated by the reducing power of the cathode material. To do. Due to the dissociated metal, a new level is formed between the level of the cathode 95 and the level of the organic light emitting layer 93, so that the electron injection barrier to the organic light emitting layer 93 can be reduced. As a result, the efficiency of electron injection from the cathode 95 to the organic light emitting layer 93 can be improved.

JP-A-11-233262 JP 2000-182774 A

“Mitsui Engineering & Ship Technical Report No. 194” issued by Mitsui Engineering & Shipbuilding Co., Ltd., June 2008, p. 11

  Among organic EL panels, a so-called top emission type that extracts light from the cathode side is attracting attention because it can effectively use the light emitted from the organic light emitting layer to improve the luminance. However, when an organic EL panel is manufactured according to the above-described procedure, high electron injection efficiency can be obtained. However, since the cathode 95 does not have optical transparency, it cannot be a top emission type. Even if the material of the cathode 95 is simply changed to a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO), these transparent conductive materials have almost no reducing power. The metal of the complex compound cannot be dissociated.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for manufacturing an organic EL element capable of achieving both a realization of a top emission type organic EL panel and an improvement in electron injection efficiency. To do.

  The organic EL device manufacturing method according to one aspect of the present invention includes a step of forming an anode on a substrate, a step of forming an organic light emitting layer above the anode, and an alkali metal compound above the organic light emitting layer. And a first material comprising at least one of an alkaline earth metal compound, a second material comprising an alkali metal constituting the first material or a metal having a reducing property with respect to the alkaline earth metal, and an electron transporting first material. A step of forming an electron injecting and transporting layer including three materials, and a step of imparting light transmittance to the second material by altering at least a part of the metal having the reducing property in the electron injecting and transporting layer. And a step of forming a light-transmitting cathode on the electron injecting and transporting layer during or after the step of imparting the light transmitting property.

  According to the method for manufacturing an organic EL element according to one aspect of the present invention, a first material made of at least one of an alkali metal compound and an alkaline earth metal compound is disposed above the organic light emitting layer, and an alkali constituting the first material. A step of forming an electron injecting and transporting layer including a second material made of a metal having a reducing property with respect to a metal or an alkaline earth metal and a third material having an electron transporting property is included. By this step, the first material and the second material act, and the alkali metal or alkaline earth metal contained in the first material is reduced. Thereby, since the alkali metal or alkaline earth metal contained in the first material is dissociated, high electron injection efficiency can be obtained as in Patent Documents 1 and 2.

  In one embodiment of the present invention, thereafter, a step of imparting light transparency to the second material is performed by altering at least a part of the reducing metal in the electron injecting and transporting layer. By performing this step, the emitted light from the organic light emitting layer passes through the electron injecting and transporting layer without being shielded by the second material. In addition, since the cathode formed on the electron injecting and transporting layer also has optical transparency, the cathode does not block the light emitted from the organic light emitting layer.

  Therefore, according to one embodiment of the present invention, it is possible to provide a method of manufacturing an organic EL element that can achieve both the realization of a top emission type organic EL panel and the improvement of electron injection efficiency.

1 is a partial cross-sectional view showing a configuration of an organic EL panel 10 according to Embodiment 1. FIG. 2 is a schematic plan view showing the shape of a bank 15 in the organic EL panel 10 according to Embodiment 1. FIG. 5 is a diagram illustrating an example of a manufacturing process of the organic EL panel 10 according to Embodiment 1. FIG. 5 is a diagram illustrating an example of a manufacturing process of the organic EL panel 10 according to Embodiment 1. FIG. 5 is a diagram illustrating an example of a manufacturing process of the organic EL panel 10 according to Embodiment 1. FIG. 1 is a partial cross-sectional view showing a configuration of an organic EL panel 10 according to Embodiment 1. FIG. It is a figure which shows the transmission spectrum of the laminated body which consists of a 1st mixed layer, an aluminum layer, and an ITO layer. It is a figure which shows the transmission spectrum of a glass substrate, and the transmission spectrum of the laminated body of a glass substrate and an aluminum oxide thin film. 6 is a diagram illustrating an example of a manufacturing process of an organic EL panel according to a modification of the first embodiment. FIG. FIG. 6 is a partial cross-sectional view showing a configuration of an organic EL panel according to a modification of the first embodiment. 5 is a diagram illustrating an example of a manufacturing process of an organic EL panel according to Embodiment 2. FIG. 5 is a partial cross-sectional view showing a configuration of an organic EL panel according to Embodiment 2. FIG. 5 is a diagram illustrating an example of a manufacturing process of an organic EL panel according to Embodiment 3. FIG. 5 is a partial cross-sectional view showing a configuration of an organic EL panel according to Embodiment 3. FIG. It is sectional drawing which shows typically the structure of the organic EL element 90 which concerns on patent document 1,2.

<< Outline of One Embodiment of the Present Invention >>
The method for manufacturing an organic EL device according to one embodiment of the present invention includes a step of forming an anode on a substrate, a step of forming an organic light emitting layer above the anode, and an alkali metal compound above the organic light emitting layer. And a first material comprising at least one of an alkaline earth metal compound, a second material comprising an alkali metal constituting the first material or a metal having a reducing property with respect to the alkaline earth metal, and an electron transporting first material. A step of forming an electron injecting and transporting layer including three materials, and a step of imparting light transmittance to the second material by altering at least a part of the metal having the reducing property in the electron injecting and transporting layer. And a step of forming a light-transmitting cathode on the electron injecting and transporting layer during or after the step of imparting the light transmitting property.

Further, in a specific aspect of the method for producing an organic EL element according to one embodiment of the present invention, the cathode is made of a conductive oxide, and the step of forming the cathode is performed during the step of imparting the light transmittance. By forming the cathode on the electron injecting and transporting layer, at least a part of the reducing metal is oxidized, and the second material is imparted with optical transparency.
Moreover, in the specific situation of the manufacturing method of the organic EL element which concerns on 1 aspect of this invention, the layer containing the said 1st material and the said 3rd material, and the layer containing the said 2nd material above the said organic light emitting layer. The electron injecting and transporting layer is formed by forming sequentially.

Moreover, in the specific situation of the manufacturing method of the organic EL element which concerns on 1 aspect of this invention, the film thickness of the layer containing the said 2nd material is 0.1 nm or more and 10 nm or less.
Moreover, in the specific aspect of the manufacturing method of the organic EL element which concerns on 1 aspect of this invention, the process which provides the said light transmittance changes the whole metal which has the said reducing property in the layer containing the said 2nd material. Is done.

  Further, in a specific aspect of the method for manufacturing an organic EL element according to one embodiment of the present invention, the step of imparting light transmittance includes a part of the reducing metal in the layer containing the second material. The second material is formed so that the film thickness of the portion of the layer containing the second material that is not deteriorated by the alteration is changed to a film thickness that has light transmittance. Alteration is performed so that the thickness of the portion of the containing layer where the metal having reducibility is altered becomes the thickness having electron injectability and light transmission.

Moreover, in the specific situation of the manufacturing method of the organic EL element which concerns on 1 aspect of this invention, the film thickness of the part which does not change and the film thickness of the said part to change are 0.1 nm or more and 10 nm or less, respectively.
Further, in a specific aspect of the method for manufacturing an organic EL element according to one embodiment of the present invention, by co-evaporating the first material, the second material, and the third material above the organic light emitting layer, The electron injecting and transporting layer is formed.

Moreover, in the specific situation of the manufacturing method of the organic EL element which concerns on 1 aspect of this invention, the film thickness of the electron injection transport layer formed of the said co-evaporation is 0.1 nm or more and 100 nm or less.
Moreover, in the specific situation of the manufacturing method of the organic EL element which concerns on 1 aspect of this invention, the layer containing the said 3rd material and the layer containing the said 1st material and the said 2nd material are provided above the said organic light emitting layer. The electron injecting and transporting layer is formed by forming sequentially.

Moreover, in the specific situation of the manufacturing method of the organic EL element which concerns on 1 aspect of this invention, the said conductive oxide is indium tin oxide or indium zinc oxide.
Moreover, in the specific situation of the manufacturing method of the organic EL element which concerns on 1 aspect of this invention, the metal which has the said reducing property is aluminum.
Moreover, in the specific aspect of the manufacturing method of the organic EL element which concerns on 1 aspect of this invention, in the process of providing the said light transmittance, by oxidizing or nitriding the said metal which has the said reducing property, it becomes said 2nd material. Light transparency is imparted.

Moreover, in the specific situation of the manufacturing method of the organic EL element concerning one mode of the present invention, the metal which has the reducibility is titanium.
Moreover, in the specific aspect of the manufacturing method of the organic EL element which concerns on 1 aspect of this invention, in the process which provides the said light transmittance, the metal which has the said reducing property is oxidized, and it transmits light to the said 2nd material. Sex is imparted.

In the specific aspect of the method for producing an organic EL element according to one embodiment of the present invention, the first material is any one of lithium quinoline, lithium fluoride, and sodium fluoride.
An organic EL device according to an aspect of the present invention includes an anode formed on a substrate, an organic light emitting layer formed above the anode, an organic light emitting layer formed above the organic light emitting layer, and an alkali metal compound and an alkaline earth. An electron injecting and transporting layer comprising: a first material comprising at least one of an organometallic compound; a second material comprising a metal excluding an alkali metal and an alkaline earth metal; and a third material having an electron transporting property; And a light-transmitting cathode formed on the substrate.

Further, in a specific aspect of the organic EL element according to one embodiment of the present invention, the metal excluding the alkali metal and the alkaline earth metal is reducible with respect to the alkali metal or the alkaline earth metal constituting the first material. Have
Further, in a specific aspect of the organic EL element according to one embodiment of the present invention, the electron injecting and transporting layer includes a layer including the first material and the third material, and a layer including the second material in order. It is formed on the light emitting layer.

Moreover, in the specific situation of the organic EL element which concerns on 1 aspect of this invention, the film thickness of the layer containing the said 2nd material is 0.1 nm or more and 10 nm or less.
Further, in a specific aspect of the organic EL element according to one embodiment of the present invention, the electron injecting and transporting layer is a layer including the first material and the third material, a compound of the second material, and is light transmissive. Are sequentially formed on the organic light emitting layer.

Further, in a specific aspect of the organic EL device according to one embodiment of the present invention, the layer including the first material and the third material, the layer made of the compound of the second material and having light transmittance. In the vicinity of, alkali metal or alkaline earth metal is dissociated from the first material.
Further, in a specific aspect of the organic EL element according to one aspect of the present invention, the electron injecting and transporting layer includes a layer including the first material and the third material, a layer including only the second material, and the second material. A layer made of a compound of materials and having light transparency is sequentially formed on the organic light emitting layer.

Further, in a specific aspect of the organic EL element according to one embodiment of the present invention, the thickness of the layer made of only the second material and the layer made of the second material and having light transparency The film thicknesses are 0.1 nm or more and 10 nm or less, respectively.
Further, in a specific aspect of the organic EL element according to one embodiment of the present invention, in the layer including the first material and the third material, in the vicinity of the layer including only the second material, the first material is alkalinized. Metal or alkaline earth metal is dissociated.

Further, in a specific aspect of the organic EL element according to one embodiment of the present invention, the electron injecting and transporting layer includes a layer containing the third material, and a layer containing the first material and the second material in order. It is formed on the light emitting layer.
Moreover, in the specific situation of the organic EL element which concerns on 1 aspect of this invention, the said cathode consists of indium tin oxide or indium zinc oxide.

In the specific aspect of the organic EL element according to one embodiment of the present invention, the second material is aluminum or titanium.
In a specific aspect of the organic EL device according to one embodiment of the present invention, the compound of the second material and having light transparency is any one of aluminum oxide, aluminum nitride, and titanium oxide.

In the specific aspect of the organic EL device according to one embodiment of the present invention, the first material is any one of lithium quinoline, lithium fluoride, and sodium fluoride.
<< Aspect 1 >>
[Configuration of organic EL panel]
FIG. 1 is a partial cross-sectional view showing the configuration of the organic EL panel 10. The organic EL panel 10 is, for example, a so-called top emission type organic EL panel in which the upper side of the figure is the display surface. In the organic EL panel 10, an organic EL element having an organic light emitting layer 16 corresponding to one of red (R), green (G), and blue (B) emission colors is a subpixel 100, and the subpixel 100 is in a matrix form. It is arranged.

As shown in FIG. 1, the organic EL panel 10 includes an anode 12, an organic light emitting layer 16, an electron injection transport layer 17, and a cathode 18 as main components.
<Substrate 11, anode 12, ITO layer 13>
The substrate 11 is a portion that becomes a base material of the organic EL panel 10, and includes, for example, alkali-free glass, soda glass, non-fluorescent glass, phosphate glass, borate glass, quartz, acrylic resin, styrene resin, and polycarbonate resin. , Epoxy resin, polyethylene, polyester, silicone resin, or an insulating material such as alumina.

  Although not shown, a TFT (thin film transistor) for driving the organic EL element is formed on the surface of the substrate 11, and an anode 12 is formed thereabove. The anode 12 is made of, for example, APC (alloy of silver, palladium, copper), ARA (alloy of silver, rubidium, gold), MoCr (alloy of molybdenum and chromium), NiCr (alloy of nickel and chromium), etc. Can do.

The ITO layer 13 is interposed between the anode 12 and the hole injection layer 14 and has a function of improving the bonding property between the layers.
<Hole injection layer 14>
The hole injection layer 14 may be, for example, an oxide such as silver (Ag), molybdenum (Mo), chromium (Cr), vanadium (V), tungsten (W), nickel (Ni), iridium (Ir), or It is a layer made of a conductive polymer material such as PEDOT (mixture of polythiophene and polystyrene sulfonic acid). Among the above, the hole injection layer 14 made of metal oxide has a function of injecting and transporting holes to and from the organic light emitting layer 16 in a stable manner or assisting the generation of holes.

<Bank 15>
On the surface of the hole injection layer 14, a bank 15 is provided for defining an opening 15 a serving as a region where the organic light emitting layer 16 is formed. The bank 15 is formed to have a certain trapezoidal cross section, and is made of an insulating organic material (for example, acrylic resin, polyimide resin, novolac type phenol resin, etc.).

  FIG. 2 is a schematic plan view showing the bank 15 in the organic EL panel 10. In the organic EL panel 10 according to this embodiment, a line bank (line bank) 15 is employed as an example. Specifically, each bank 15 extends in the Y-axis direction, and partitions between adjacent subpixels 100 in the X-axis direction. The sub-pixels 100 are formed so as to have different emission colors for each of the areas partitioned by the bank 15. For example, the sub-pixels 100 (R), the G sub-pixels 100 (G), and the B sub-pixels 100 are formed. One pixel (one pixel) is constituted by a combination of three subpixels of the subpixel 100 (B).

The partial cross-sectional view shown in FIG. 1 corresponds to the AA ′ cross-sectional view in FIG.
<Organic light emitting layer 16>
Returning to FIG. 1, an organic light emitting layer 16 corresponding to one of R, G, and B emission colors is formed on the surface of the hole injection layer 14 partitioned by the opening 15 a of the bank 15. The organic light emitting layer 16 is a portion that emits light by recombination of carriers, and is configured to include an organic material corresponding to one of R, G, and B colors.

  Examples of materials that can be used for the organic light emitting layer 16 include polyparaphenylene vinylene (PPV), polyfluorene, and, for example, an oxinoid compound, a perylene compound, and a coumarin described in a patent publication (JP-A-5-163488). Compound, azacoumarin compound, oxazole compound, oxadiazole compound, perinone compound, pyrrolopyrrole compound, naphthalene compound, anthracene compound, fluorene compound, fluoranthene compound, tetracene compound, pyrene compound, coronene compound, quinolone compound, azaquinolone compound, pyrazoline derivative and Pyrazolone derivatives, rhodamine compounds, chrysene compounds, phenanthrene compounds, cyclopentadiene compounds, stilbene compounds, diphenylquinone compounds, styryl compounds, butyl compounds Diene compound, dicyanomethylenepyran compound, dicyanomethylenethiopyran compound, fluorescein compound, pyrylium compound, thiapyrylium compound, serenapyrylium compound, telluropyrylium compound, aromatic ardadiene compound, oligophenylene compound, thioxanthene compound, cyanine compound, acridine compound, Examples thereof include a metal complex of an 8-hydroxyquinoline compound, a metal complex of a 2-bipyridine compound, a complex of a Schiff salt and a group III metal, an oxine metal complex, a rare earth complex, and other fluorescent substances.

<Electron injection transport layer 17>
The electron injecting and transporting layer 17 formed above the organic light emitting layer has a function of injecting and transporting electrons injected from the cathode 18 to the organic light emitting layer 16. The electron injecting and transporting layer 17 includes a first material made of at least one of an alkali metal compound and an alkaline earth metal compound, a second material made of a metal excluding an alkali metal and an alkaline earth metal, and a third material having an electron transporting property. Comprising.

As the first material, for example, an organometallic complex having quinolinol or phthalocyanine represented by lithium quinoline as a ligand, an alkali metal represented by lithium fluoride, sodium fluoride or the like (Li, Na, Cs, Mg) And oxides, fluorides, nitrides, and the like of alkaline earth metals (Ca, Sr, Ba, etc.).
Although it has been described that the second material is made of a metal excluding alkali metal and alkaline earth metal, specifically, the second material is made of a metal having a reducing property with respect to the alkali metal or alkaline earth metal constituting the first material. The second material of this embodiment is simple aluminum.

  Examples of the third material include nitro-substituted fluorenone derivatives, thiopyrandioxide derivatives, diphequinone derivatives, perylene tetracarboxyl derivatives, anthraquinodimethane derivatives, fluorenylidenemethane derivatives, anthrone derivatives, oxadiazole derivatives, perinone derivatives, Examples thereof include quinoline complex derivatives (all described in JP-A-5-163488).

  In the vicinity of the cathode 18 in the electron injection transport layer 17, alkali metal or alkaline earth metal is dissociated from the first material. Since the alkali metal or alkaline earth metal is dissociated from the first material, the level of the cathode 18 and the level of the organic light emitting layer 16 are determined based on the same principle as that of the organic EL element 90 according to Patent Documents 1 and 2. A new level is formed between the two. As a result, the electron injection barrier from the cathode 18 to the organic light emitting layer 16 is reduced, and high electron injection efficiency is obtained. The alkali metal or alkaline earth metal from the first material is dissociated by the reducing power of the third material during the manufacturing process. Details of this will be described in the section of a method for manufacturing an organic EL panel.

Note that at least alkali metal or alkaline earth metal is required to form a new level, but these metals are unstable (chemically active) in a single state. Therefore, these metals are contained in the first material in the state of an alkali metal compound and an alkaline earth metal compound.
Further, in the electron injecting and transporting layer 17, the second material exists as a compound of the second material. The compound of the second material is light transmissive and is aluminum oxide in the present embodiment. With such a configuration, the emitted light from the organic light emitting layer 16 can pass through the electron injecting and transporting layer 17. As will be described later, the cathode 18 formed on the electron injecting and transporting layer 17 is also light transmissive, so that the cathode 18 does not block the light emitted from the organic light emitting layer 16. As a result, the top emission type organic EL panel 10 can be configured.

  Here, in the manufacturing process of the organic EL panel 10, the second material is contained in the electron injecting and transporting layer 17 in the state of a simple substance of aluminum during and immediately after the process of forming the electron injecting and transporting layer 17. The aluminum oxide contained in the electron injecting and transporting layer 17 is generated as a result of alteration of a single aluminum through a process of imparting light transmittance. Here, “aluminum is altered” means that aluminum undergoes a chemical reaction.

The step of imparting light transmittance is performed after the step of forming the electron injecting and transporting layer 17 and is performed simultaneously with the step of forming the cathode 18 in this embodiment. Details of this will be described later.
<Cathode 18>
In order to realize a top emission type organic EL panel, the cathode 18 formed on the electron injecting and transporting layer 17 in the present embodiment is formed of a light-transmitting conductive oxide material such as ITO or IZO. Has been.

<Sealing layer 19>
The sealing layer 19 formed on the cathode 18 is provided to protect the organic light emitting layer 16 and the cathode 18 from moisture or oxygen that has entered the organic EL panel 10. Since the organic EL panel 10 is a top emission type, a light transmissive material such as SiN (silicon nitride) or SiON (silicon oxynitride) is employed as the material of the sealing layer 19.

<Others>
Although not particularly shown, a sealing substrate facing the substrate 11 is provided above the sealing layer 19. Furthermore, the space formed by the sealing layer 19 and the sealing substrate may be filled with an insulating layer made of an insulating material for the purpose of preventing moisture or oxygen from entering the organic EL panel 10. Since the organic EL panel 10 is a top emission type, the material used for the insulating layer needs to be formed of a light transmissive material such as SiN or SiON.

  Further, a hole transport layer that promotes transport of holes from the hole injection layer 14 to the organic light emitting layer 16 may be further formed between the hole injection layer 14 and the organic light emitting layer 16. Examples of materials used for the hole transport layer include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, Styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, polyphyllin compounds, aromatic tertiary amine compounds, styrylamine compounds, butadiene compounds, polystyrene derivatives, hydrazone derivatives, triphenylmethane derivatives, tetraphenylbenzine derivatives ( All are described in JP-A-5-163488).

[Method for manufacturing organic EL panel]
First, the substrate 11 is placed in a chamber of a sputter deposition apparatus. Then, a predetermined sputtering gas is introduced into the chamber, and the anode 12 is formed on the basis of a reactive sputtering method, a vacuum deposition method, or the like (FIG. 3A).
Subsequently, an ITO layer 13 is formed on the anode 12 based on the sputtering method in the above chamber (FIG. 3B). Next, a hole injection layer 14 is formed on the surface of the substrate 11 including each surface of the ITO layer 13 (FIG. 3B). The hole injection layer 14 is formed by post-oxidation of a metal film formed using a sputtering method or the like, or metal oxide film formation by a reactive sputtering method or the like.

  Next, as the bank material, for example, a photosensitive resist material, preferably a photoresist material containing a fluorine-based material is prepared. After this bank material is uniformly applied on the hole injection layer 14 and prebaked, a mask having a pattern that can form the opening 15a is overlaid. Then, after exposure from above the mask, uncured excess bank material is washed out with a developer. Finally, the bank 15 is completed by washing with pure water (FIG. 3C).

  Next, an ink 16a containing a material and a solvent constituting the organic light emitting layer is dropped on the opening 15a (FIG. 3C) of the bank 15 based on the inkjet method (FIG. 4A). The solvent is removed by volatilization. Thereby, the organic light emitting layer 16 is formed (FIG. 4B). In addition, the formation method of the organic light emitting layer 16 is not limited to the inkjet method, For example, it is good also as forming by well-known methods, such as a gravure printing method, a dispenser method, a nozzle coating method, intaglio printing, and relief printing.

4C, 5A, and 5B show a step of forming the electron injecting and transporting layer 17, a step of imparting light transparency to the second material, and a step of forming the cathode 18. Yes.
First, as shown in FIG. 4C, the layer 20 including the first material and the third material is formed above the organic light emitting layer 16. Hereinafter, the layer 20 including the first material and the third material is referred to as a first mixed layer 20. The first mixed layer 20 can be formed based on, for example, a co-evaporation method, a co-sputtering method, or the like. When it is desired to reduce the damage to the organic light emitting layer 16 which is the film formation target of the first mixed layer 20, it is more preferable to perform the co-evaporation method. Moreover, it is desirable that the film thickness of the first mixed layer 20 is 0.1 [nm] or more and 100 [nm] or less from the viewpoint of light transmittance.

  Subsequently, as shown in FIG. 5A, a layer 22 made of a single aluminum is formed on the first mixed layer 20. Hereinafter, the layer 22 made of a single aluminum is referred to as an aluminum layer 22. The aluminum layer 22 can be formed on the basis of the vapor deposition method, the sputtering method, or the like, similar to the first mixed layer 20, but it is more preferable to perform the vapor deposition method when it is desired to reduce damage to the organic light emitting layer 16. Moreover, it is desirable that the film thickness of the aluminum layer 22 is 0.1 [nm] or more and 10 [nm] or less from the viewpoint of light transmittance. Thus, in the present embodiment, the electron injecting and transporting layer 17 ′ is formed by sequentially forming the first mixed layer 20 and the aluminum layer 22.

  During the step of forming the electron injecting and transporting layer 17 ′, the first material in the first mixed layer 20 and the aluminum layer 22 act in the electron injecting and transporting layer 17, so that an alkali metal contained in the first material or Alkaline earth metals are reduced. At this time, a separate process such as a heat treatment is unnecessary. Thereby, the alkali metal or alkaline earth metal contained in the first material is dissociated, and a level based thereon is formed at the interface between the first mixed layer 20 and the aluminum layer 22.

  Next, as shown in FIG. 5B, a light-transmitting cathode 18 is formed on the electron injecting and transporting layer 17 '. Specifically, a transparent conductive oxide such as ITO or IZO is formed by vapor deposition or sputtering. At this time, when a conductive oxide is used as the material of the cathode 18 as in this embodiment, the entire aluminum layer 22 is oxidized by forming the conductive oxide on the electron injection transport layer 17 ′. Then, a layer 21 made of aluminum oxide is formed (FIG. 5B). Hereinafter, the layer 21 made of aluminum oxide is referred to as an aluminum oxide layer 21.

As a target used when forming a transparent conductive film such as ITO based on a sputtering method, an alloy target of indium and tin or a sintered body of indium oxide (In ₂ O ₃ ) and tin oxide (SnO ₂ ) can be used. Oxide targets are known. Regardless of which target is used, oxygen is introduced into the chamber. This oxygen introduced into the chamber oxidizes single aluminum. Further, since aluminum oxide is thermodynamically more stable than single aluminum, only the region on the cathode 18 side of the aluminum layer 22 depends on the film thickness of the aluminum layer 22, the oxygen concentration in the chamber, the substrate temperature, and the like. Instead, the entire aluminum layer 22 can be oxidized.

Thus, according to this embodiment, the step of forming the cathode is performed during the step of imparting light transparency. Thereby, light transmittance is imparted to the second material made of a single aluminum, the electron injection transport layer 17 is formed, and the cathode 18 is formed.
In the step of forming the electron injection / transport layer 17 ′, once dissociation of alkali metal or alkaline earth metal occurs in the first mixed layer 20, the dissociated metal exists stably in the electron injection / transport layer 17. It is considered possible. Therefore, a state in which a new level is formed is maintained even if no further dissociation occurs after the step of forming the electron injection / transport layer 17 ′, and a high electron injection property is maintained during use of the organic EL panel 10. Conceivable. After the step of forming the electron injecting and transporting layer 17 ′, the second material does not need to exist as a simple substance with aluminum. Therefore, in this embodiment, the second material made of a single aluminum is entirely oxidized. I am going to do that.

  Then, as shown in FIG. 5C, a sealing layer 19 is formed on the cathode 18 based on a vapor deposition method, a sputtering method, or the like. As described above, the sputtering method generally causes more damage to the film formation target than the vapor deposition method. However, since the electron injecting and transporting layer 17 is formed on the organic light emitting layer 16, the organic light emitting layer 16 is not easily damaged even when the cathode 18 is formed by sputtering.

The organic EL panel 10 is completed through the above steps.
FIG. 6 is a partial cross-sectional view showing the configuration of the organic EL panel 10 according to Embodiment 1, and corresponds to an enlarged view of a region (X) in FIG.
As shown in FIG. 6, the electron injecting and transporting layer 17 in the organic EL panel 10 completed as a result of the manufacturing steps described with reference to FIGS. 3 to 5 has a two-layer structure including a first mixed layer 20 and an aluminum oxide layer 21. ing. Further, in the vicinity of the aluminum oxide layer 21 (a layer made of a compound of the second material and having light transparency) in the first mixed layer 20, the alkali metal or the alkaline earth metal is dissociated from the first material. Yes. Furthermore, since the aluminum oxide layer 21 is a layer formed by altering the aluminum layer 22, the film thickness of the aluminum oxide layer 21 is equal to the film thickness of the aluminum layer 22, and is 0.1 [nm] or more as described above. 10 [nm] or less.

Here, from the viewpoint of light transmittance in the electron injecting and transporting layer 17, not only a part of the aluminum layer 22 in the electron injecting and transporting layer 17 ′ is changed into aluminum oxide, but as in this embodiment, It is desirable to transform all aluminum into aluminum oxide. This will be described with reference to FIGS.
FIG. 7 is a diagram showing a transmission spectrum of a laminate composed of the first mixed layer, the aluminum layer, and the ITO layer.

  Transmission spectra were performed on three types of laminates. In each stacked body, the first mixed layer includes a first material (described as “Liq” in FIG. 7) and a third material (described as “ETL” in FIG. 7). Lithium quinoline was used as the first material. The aluminum layer and the ITO layer are described as “AL” and “ITO” in FIG. 7, respectively. Further, the numerical value in parentheses in FIG. 7 represents the film thickness [nm] of the corresponding layer. That is, the difference between the stacked bodies is only the film thickness of the aluminum layer. In the graph shown in FIG. 7, the horizontal axis represents wavelength [nm] and the vertical axis represents transmittance [%].

  From the spectrum shown in FIG. 7, it can be seen that even when the film thickness of the aluminum layer changes by only a few nm, the transmittance for light in the visible light region (approximately 400 to 780 [nm] region) is greatly reduced. From this result, it can be seen that it is desirable from the viewpoint of light transmittance in the electron injecting and transporting layer 17 to change all aluminum into aluminum oxide as in this embodiment.

  FIG. 8 is a diagram showing a transmission spectrum of a glass substrate and a transmission spectrum of a laminate of the glass substrate and the aluminum oxide thin film. In the graph shown in FIG. 8, the horizontal axis represents wavelength [nm] and the vertical axis represents transmittance [%]. The film thickness of the aluminum oxide thin film is 97 [nm], which is much thicker than the film thickness of the aluminum oxide layer 21. This spectrum is described in Non-Patent Document 1.

  As can be seen from the spectrum shown in FIG. 8, the transmittance of the laminated body of the glass substrate and the aluminum oxide thin film is lower than the transmittance of the glass substrate, but still has a high transmittance of about 90% in the visible light region. Have. Thus, it can be seen that even if the aluminum oxide layer 21 is present in the electron injecting and transporting layer 17, the light transmittance in the electron injecting and transporting layer 17 is hardly affected.

[Summary]
As described above, according to this embodiment, the alkali metal or alkaline earth metal contained in the first material is dissociated in the step of forming the electron injecting and transporting layer. A new level is formed between the level of the organic light emitting layer. As a result, the electron injection barrier can be reduced, and as a result, the electron injection efficiency can be improved.

  In addition, by using a transparent conductive film as a material for the cathode and applying a process for imparting light transparency to the second material, the emitted light from the organic light emitting layer can be transmitted through the electron injecting and transporting layer and the cathode. . A top emission type organic EL panel can be constituted by using an organic EL element produced through such steps. Further, in this embodiment, the step of imparting light transparency is performed simultaneously with the step of forming the cathode. Therefore, it is not necessary to perform another process only for imparting light transparency to the second material, and the production efficiency is not reduced.

<< Modification of Embodiment 1 >>
In the first embodiment, as shown in FIG. 5B, an example in which the entire aluminum layer 22 is changed to aluminum oxide has been shown. However, only a part of the aluminum layer 22 is changed to aluminum oxide. Also good. In this modification, an example in which only a part of the aluminum layer 22 is transformed into aluminum oxide will be described with a focus on differences from the first embodiment.

FIG. 9 is a diagram illustrating an example of a manufacturing process of the organic EL panel according to the modification of the first embodiment.
First, in FIG. 9A, the first mixed layer 20 and the aluminum layer 22 are sequentially formed above the organic light emitting layer 16 to form the electron injection / transport layer 17 ′. The steps so far are the same as those in the first embodiment. Next, as shown in FIG. 9B, a cathode 18 is formed by forming a conductive oxide film. At this time, in this modification, only a part of the aluminum layer 22, in particular, only the region on the cathode 18 side in the aluminum layer 22 is oxidized to form the electron injection / transport layer 17 </ b> A. That is, the step of imparting light transparency is performed by altering a part of the reducing metal in the layer containing the second material. The progress of oxidation with respect to the aluminum layer 22 can be adjusted by the amount of oxygen introduced into the chamber.

  In the step of forming the cathode 18 (FIG. 9B), the aluminum layer 22 is formed such that the portion of the aluminum layer 22 where the aluminum is not oxidized has a light-transmitting thickness, and the aluminum layer 22 Oxidation is performed so that the thickness of the portion where aluminum is oxidized becomes a thickness having electron injection properties and light transmission properties. Specifically, the thickness of the portion where aluminum is not oxidized and the thickness of the portion where aluminum is oxidized are set to 0.1 [nm] or more and 10 [nm] or less, respectively. If the film thickness of the portion where aluminum does not oxidize exceeds 10 [nm], light transmittance may not be ensured. Further, when the film thickness of the portion where aluminum is oxidized exceeds 10 [nm], the oxidized aluminum is an insulator, so that holes may not be injected into the organic light emitting layer 16.

Finally, as shown in FIG. 9C, an organic EL panel is completed by forming a sealing layer 19 on the cathode 18.
FIG. 10 is a partial cross-sectional view showing a configuration of an organic EL panel according to a modification of the first embodiment.
As shown in FIG. 10, the electron injection / transport layer 17 </ b> A in the organic EL panel completed as a result of the manufacturing process described in FIG. 9 has a three-layer structure including the first mixed layer 20, the aluminum layer 22, and the aluminum oxide layer 21. It has become. Further, in the vicinity of the aluminum layer 22 (a layer made of only the second material) in the first mixed layer 20, alkali metal or alkaline earth metal is dissociated from the first material. Further, as described above, the film thickness of the aluminum layer 22 and the film thickness of the aluminum oxide layer 21 are 0.1 [nm] or more and 10 [nm] or less, respectively.

As described above, also according to this modification, it is possible to realize a top emission type organic EL panel and to maintain high electron injection efficiency and manufacturing efficiency.
<< Embodiment 2 >>
In the first embodiment and the modification thereof, the electron injecting and transporting layer 17 ′ is formed by sequentially laminating the first mixed layer 20 and the aluminum layer 22, and then the electron injecting and transporting layer 17 has a two-layer or three-layer structure. The example to be explained. In the present embodiment, an example in which the electron injecting and transporting layer is one layer will be described focusing on differences from the first embodiment and modifications thereof.

FIG. 11 is a diagram illustrating a manufacturing process example of the organic EL panel according to the second embodiment.
First, as shown in FIG. 11A, the electron injecting and transporting layer 27 is formed by co-evaporating the first material, the second material, and the third material above the organic light emitting layer 16. By co-evaporation, the first material in the first mixed layer 20 and the aluminum layer 22 act in the electron injecting and transporting layer 27, whereby the alkali metal or alkaline earth metal contained in the first material is dissociated. . The thickness of the electron injecting and transporting layer 27 is preferably 0.1 [nm] or more and 100 [nm] or less.

The electron injecting and transporting layer 27 in this embodiment can be formed based on the co-sputtering method, but from the viewpoint of reducing damage to the organic light emitting layer 16, it is more preferable to form the film by the co-evaporating method. desirable.
Next, as shown in FIG. 11B, the cathode 18 is formed on the electron injection transport layer 27. In the step of forming the cathode 18, the aluminum contained in the electron injection / transport layer 27 is oxidized to aluminum oxide. At this time, only the aluminum contained in the region on the side of the cathode 18 in the electron injection / transport layer 27 may be oxidized, but from the viewpoint of light transmission, the entire aluminum contained in the electron injection / transport layer 27 is oxidized. It is desirable to change to aluminum.

Finally, as shown in FIG. 11C, an organic EL panel is completed by forming a sealing layer 19 on the cathode 18.
FIG. 12 is a partial cross-sectional view showing the configuration of the organic EL panel according to the second embodiment.
As shown in FIG. 12, the electron injecting and transporting layer 27 in the organic EL panel completed as a result of the manufacturing process described in FIG. 11 includes the first material, the second material, and the third material. It has a layer structure. In this embodiment, the alkali metal or alkaline earth metal is dissociated from the first material over the entire electron injecting and transporting layer 27.

As described above, according to this embodiment, it is possible to realize a top emission type organic EL panel and to maintain high electron injection efficiency and manufacturing efficiency. In this embodiment, since the electron injecting and transporting layer including the first material, the second material, and the third material is formed in one step, the number of manufacturing steps is reduced as compared with Embodiment 1 and its modification. It is possible.
<< Embodiment 3 >>
In the present embodiment, another example in which two electron injecting and transporting layers are formed in the same manner as in the first embodiment will be described focusing on differences from the first embodiment.

FIG. 13 is a diagram illustrating a manufacturing process example of the organic EL panel according to the third embodiment.
First, as shown in FIG. 13A, a layer 23 containing a third material is formed above the organic light emitting layer 16. The layer 23 containing the third material can be formed by vapor deposition, sputtering, or the like. In addition, the thickness of the layer 23 containing the third material is preferably 0.1 [nm] or more and 100 [nm] or less.

  Subsequently, as illustrated in FIG. 13B, the layer 24 including the first material and the second material (single aluminum) is formed on the layer 23 including the third material. Hereinafter, the layer 24 including the first material and the second material is referred to as a second mixed layer 24. That is, in the present embodiment, the electron injecting and transporting layer 37 is formed by sequentially forming the layer 23 containing the third material and the second mixed layer 24 above the organic light emitting layer 16. The second mixed layer 24 can be formed by a co-evaporation method, a co-sputtering method, or the like. The film thickness of the second mixed layer 24 is desirably 0.1 [nm] or more and 10 [nm] or less.

In the step of forming the second mixed layer 24, the alkali metal or alkaline earth metal is dissociated by reducing the alkali metal or alkaline earth metal contained in the first material by aluminum.
Then, as shown in FIG. 13C, a cathode 18 made of a conductive oxide is formed on the electron injection / transport layer 37. At this time, the simple aluminum existing in the region on the cathode 18 side in the second mixed layer 24 is oxidized to aluminum oxide, and light transmittance is imparted. In addition, the oxidation of aluminum contained in the second mixed layer 24 is desirably oxidized not only partially but entirely as in the other embodiments.

Although not shown, the organic EL panel is completed by performing a process of forming the sealing layer 19 last.
FIG. 14 is a partial cross-sectional view showing the configuration of the organic EL panel according to Embodiment 3.
As shown in FIG. 14, the electron injecting and transporting layer 37 in the organic EL panel completed as a result of the manufacturing steps described in FIG. 13 includes the layer 23 containing the third material, the second mixture containing the first material and the second material. The layer 24 has a two-layer structure in which the organic light emitting layer 16 is sequentially formed. In the present embodiment, the alkali metal or the alkaline earth metal is dissociated from the first material over the entire second mixed layer 24.

As described above, according to this embodiment, it is possible to realize a top emission type organic EL panel and to maintain high electron injection efficiency and manufacturing efficiency.
[Modifications / Others]
Although the embodiment has been described above, the present invention is not limited to the above embodiment. For example, the following modifications can be considered.

(1) If either an alkali metal or an alkaline earth metal is present in the electron injecting and transporting layer, a new level is formed between the level of the cathode and the level of the organic light emitting layer. Can do. Therefore, the first material does not necessarily need to contain both an alkali metal compound or an alkaline earth metal compound, and only one of them needs to be contained.
(2) In the embodiment described above, the step of imparting light transparency to the second material is performed using the step of forming the cathode. In other words, although the step of forming the cathode is performed during the step of imparting light transmittance, the present invention is not limited to this. After the step of forming the electron injecting and transporting layer and before the step of forming the cathode, a step of imparting light transmittance, that is, an oxidation treatment may be separately performed. As the oxidation treatment, for example, a known oxidation treatment such as UV ozone oxidation, thermal oxidation, oxygen plasma oxidation or the like can be used.

  (3) In the above embodiment, the second material is made of a single aluminum, but the present invention is not limited to this. The second material may be any metal that has a reducing property with respect to the alkali metal or alkaline earth metal contained in the first material. Examples of such a metal include aluminum, titanium, tungsten, and the like. It is done. In addition to silicon, there are silicon and the like.

In the case where titanium is used as the second material, examples of the compound of the second material that has optical transparency include titanium oxide. In this case, single titanium can be converted to titanium oxide by the same method as the oxidation of aluminum described in the embodiment.
Furthermore, although it has been described that the compound of the second material (aluminum) and having light transmittance is aluminum oxide, the present invention is not limited to this. Examples of such a compound include aluminum nitride other than aluminum oxide. In the case of using aluminum nitride, the step of imparting light transparency is performed after the step of forming the electron injecting and transporting layer and before the step of forming the cathode. Further, the step of imparting light transparency in this case is specifically nitriding.

  (4) As described above, even if the cathode of the organic EL element according to Patent Documents 1 and 2 is changed to a transparent conductive material such as ITO or IZO, the cathode made of the transparent conductive material has a function as a cathode. The metal contained in the electron injection layer cannot be dissociated. That is, there is a problem that high electron-injection property is not achieved although the function as a cathode and the realization of a high top emission type can be achieved at the same time.

  In addition, a configuration in which the cathode of the organic EL element according to Patent Documents 1 and 2 is formed to have a very thin film thickness so as to have light transmittance is also conceivable. However, since the resistance value of the cathode is greatly increased this time, there is a problem that the cathode made of a thin film has no function as a cathode. That is, there is a problem that although it is possible to achieve both a high electron injection property and a top emission type, it does not have a function as a cathode.

On the other hand, according to the method for manufacturing an organic EL element according to one embodiment of the present invention, it is possible to manufacture an organic EL element that satisfies all of the expression of a function as a cathode, high electron injection property, and realization of a top emission type. It is.
(5) In the present invention, the ITO layer, hole injection layer, hole transport layer, bank and sealing layer are not essential constituent requirements. The present invention can also be applied to organic EL elements that do not have these configurations. On the contrary, other constituent elements such as a hole blocking layer may be further included.

(6) In the above embodiment, the example in which the hole injection layer is formed on the entire surface so as to cover the upper side of the substrate is shown, but the present invention is not limited to this. The hole injection layer may be formed only on the ITO layer. Moreover, it is good also as forming so that only the side surface and upper surface of an ITO layer may be covered.
(7) When the anode is formed of a silver (Ag) -based material, it is desirable to form an ITO layer thereon as in the above embodiment. When the anode is formed of an aluminum-based material, it is possible to eliminate the ITO layer and make the anode have a single layer structure.

(8) The method of manufacturing the organic EL panel described in the above embodiment is merely an example, and includes a step of forming other components, for example, a step of forming the hole blocking layer described above. Also good. Moreover, when forming the organic EL element which does not have an ITO layer, a positive hole injection layer, a bank, and a sealing layer, it cannot be overemphasized that the process of forming these can be skipped.
Alternatively, the layer described as being formed using the vacuum film forming method may be formed by a coating method such as an ink jet method, and conversely, the layer described as being formed using the ink jet method is, for example, It is good also as forming by a vacuum film-forming method.

(9) In the above embodiment, an organic EL panel having a configuration in which a plurality of organic EL elements are integrated on a substrate as subpixels has been described. However, the present invention is not limited to this example, and an organic EL element is used singly. It is also possible. As what uses an organic EL element alone, an illumination apparatus etc. are mentioned, for example.
(10) In the above embodiment, the organic EL panel is a full-color display panel in which R, G, and B emit light, but the present invention is not limited to this. The organic EL panel may be a display panel in which a plurality of R, G, B, white, and other monochrome organic EL elements are arranged. Furthermore, it is good also as an organic electroluminescent panel of the single color display which has an organic electroluminescent element only in any one color.

  (11) In the above embodiment, an organic material is used as the bank material, but an inorganic material can also be used. In this case, the bank material layer can be formed by coating, for example, as in the case of using an organic material. Furthermore, although the above-mentioned organic EL panel employs a line bank system in which a plurality of line-shaped banks are arranged in parallel and the organic light emitting layer is partitioned into stripes, the present invention is not limited to this. For example, a so-called pixel bank system may be used in which banks are formed in a grid pattern (lattice shape) and the periphery of each subpixel is surrounded by the banks.

  (12) “A consists of a” in this specification includes not only a case where A contains only a but also a small amount of impurities that can be mixed at a normal level in the manufacturing process. Cases are also included. For example, “the second material is made of a single aluminum” includes not only the case where the second material contains only aluminum but also the case where a trace amount of impurities other than aluminum is mixed.

(13) In the above embodiment, the organic EL element applicable to the top emission type organic EL panel that extracts light from the cathode side has been described, but the present invention is not limited to this. By using a transparent conductive material for the anode as well as the cathode, the present invention can be applied to a double-sided organic EL panel that extracts light from both the anode side and the cathode side.
(14) The materials, numerical values, and the like used in the above-described embodiment are merely preferred examples and are not limited to this embodiment. In addition, changes can be made as appropriate without departing from the scope of the technical idea of the present invention. Furthermore, the scale of the members in each drawing is different from the actual one. Note that the symbol “˜” used to indicate a numerical range includes numerical values at both ends.

  The method for producing an organic EL element of the present invention is suitable for, for example, a method for producing an organic EL element used for home or public facilities, various displays for business use, television devices, displays for portable electronic devices, and the like. Is available.

DESCRIPTION OF SYMBOLS 10 Organic EL panel 11 Substrate 12 Anode 13 ITO layer 14 Hole injection transport layer 15 Bank 15a opening 16 Organic light emitting layer 16a Ink 17 Mixed layer 18 Cathode 19 Sealing layer 20 First mixed layer 21 Aluminum oxide layer 22 Aluminum layer 23 Layer containing third material 24 Second mixed layer 100 Subpixel 90 Organic EL element 91 Anode 92 Hole transport layer 93 Organic light emitting layer 94 Electron injection layer 95 Cathode

Claims (30)

Forming an anode on the substrate;
Forming an organic light emitting layer above the anode;
Above the organic light emitting layer, a first material composed of at least one of an alkali metal compound and an alkaline earth metal compound, and a metal having a reducing property with respect to an alkali metal or an alkaline earth metal constituting the first material. Forming an electron injecting and transporting layer including a second material and a third material having an electron transporting property;
Imparting light transparency to the second material by altering at least a part of the reducing metal in the electron injecting and transporting layer;
Forming a light-transmitting cathode on the electron injecting and transporting layer during or after the step of imparting the light transmittance,
Manufacturing method of organic EL element. The cathode is made of a conductive oxide,
A step of forming the cathode during the step of imparting the light transmittance;
By forming the cathode on the electron injecting and transporting layer, at least a part of the reducing metal is oxidized, and light transmittance is imparted to the second material.
The manufacturing method of the organic EL element of Claim 1. Forming the electron injecting and transporting layer by sequentially forming a layer containing the first material and the third material and a layer containing the second material above the organic light emitting layer;
The manufacturing method of the organic EL element of Claim 1. The thickness of the layer containing the second material is not less than 0.1 nm and not more than 10 nm.
The manufacturing method of the organic EL element of Claim 3. The step of imparting the light transmittance is performed by altering the entire metal having the reducing property in the layer containing the second material.
The manufacturing method of the organic EL element of Claim 3. The step of imparting light transmittance is performed by altering a part of the metal having the reducing property in the layer containing the second material,
Of the layer containing the second material, the thickness of the portion where the metal having reducibility does not change becomes the film thickness having light transmittance, and the reducing property of the layer containing the second material. Alteration is performed so that the film thickness of the portion where the metal having the property is changed becomes a film thickness having electron injection property and light transmission property,
The manufacturing method of the organic EL element of Claim 3. The film thickness of the non-denatured portion and the film thickness of the denatured portion are 0.1 nm or more and 10 nm or less, respectively.
The manufacturing method of the organic EL element of Claim 6. Forming the electron injecting and transporting layer by co-evaporating the first material, the second material and the third material above the organic light emitting layer;
The manufacturing method of the organic EL element of Claim 1. The thickness of the electron injecting and transporting layer formed by the co-evaporation is 0.1 nm or more and 100 nm or less.
The manufacturing method of the organic EL element of Claim 8. Forming the electron injecting and transporting layer by sequentially forming a layer containing the third material and a layer containing the first material and the second material above the organic light emitting layer;
The manufacturing method of the organic EL element of Claim 1. The conductive oxide is indium tin oxide or indium zinc oxide.
The manufacturing method of the organic EL element of Claim 2. The reducing metal is aluminum.
The manufacturing method of the organic EL element of Claim 1. In the step of imparting light transparency, the second material is rendered light transmissive by oxidizing or nitriding the reducing metal.
The manufacturing method of the organic EL element of Claim 12. The reducing metal is titanium.
The manufacturing method of the organic EL element of Claim 1. In the step of imparting the light transmittance, the second material is imparted with a light transmittance by oxidizing the reducing metal.
The manufacturing method of the organic EL element of Claim 14. The first material is any one of lithium quinoline, lithium fluoride, and sodium fluoride.
The manufacturing method of the organic EL element of Claim 1. An anode formed on the substrate;
An organic light emitting layer formed above the anode;
A first material made of at least one of an alkali metal compound and an alkaline earth metal compound; a second material made of a metal excluding an alkali metal and an alkaline earth metal; and an electron transporting property. An electron injecting and transporting layer containing a third material;
A light-transmissive cathode formed on the electron injecting and transporting layer,
Organic EL element. The metal excluding the alkali metal and alkaline earth metal has a reducing property with respect to the alkali metal or alkaline earth metal constituting the first material.
The organic EL device according to claim 17. The electron injecting and transporting layer is
A layer including the first material and the third material, and a layer including the second material are sequentially formed on the organic light emitting layer;
The organic EL device according to claim 17 or 18. The thickness of the layer containing the second material is not less than 0.1 nm and not more than 10 nm.
The organic EL device according to claim 19. The electron injecting and transporting layer is
A layer including the first material and the third material, and a layer made of a compound of the second material and having light transmission properties are sequentially formed on the organic light emitting layer;
The organic EL device according to claim 19. In the layer containing the first material and the third material, an alkali metal or an alkaline earth metal is dissociated from the first material in the vicinity of the layer made of the compound of the second material and having light transmittance. doing,
The organic EL device according to claim 21. The electron injecting and transporting layer is
A layer including the first material and the third material, a layer made of only the second material, and a layer made of a compound of the second material and having light transmission properties are sequentially formed on the organic light emitting layer. Become,
The organic EL device according to claim 19. The film thickness of the layer made of only the second material and the film thickness of the layer made of a compound of the second material and having light transmittance are 0.1 nm or more and 10 nm or less, respectively.
The organic EL device according to claim 23. In the layer containing the first material and the third material, in the vicinity of the layer made of only the second material, alkali metal or alkaline earth metal is dissociated from the first material.
The organic EL device according to claim 23. The electron injecting and transporting layer is
A layer including the third material, a layer including the first material and the second material are sequentially formed on the organic light emitting layer;
The organic EL device according to claim 17. The cathode is made of indium tin oxide or indium zinc oxide,
The organic EL device according to claim 17. The second material is aluminum or titanium.
The organic EL device according to claim 17 or 18. The compound of the second material having light transparency is one of aluminum oxide, aluminum nitride, and titanium oxide.
The organic EL element according to claim 21 or 22. The first material is any one of lithium quinoline, lithium fluoride, and sodium fluoride.
The organic EL device according to claim 17.

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