JP2010103460A - Organic electroluminescence element, method for manufacturing organic electroluminescence element, and display unit - Google Patents

Abstract

The present invention has been made in view of the above problems, and it is an object of the present invention to provide an organic EL device having high light emission efficiency, high light emission luminance, long life, and no defects, in which the influence of deterioration factors is prevented. And
A substrate, a first electrode provided on the substrate, a light emitting medium layer including at least an organic light emitting layer and a molybdenum oxide-containing layer provided on the first electrode, and sandwiching the light emitting medium layer The organic electroluminescence device has a second electrode facing the first electrode, and the molybdenum oxide-containing layer contains at least molybdenum trioxide and another inorganic compound.
[Selection] Figure 1

Description

The present invention relates to an organic EL element utilizing an electroluminescence (hereinafter abbreviated as EL) phenomenon of an organic thin film, a method for manufacturing the organic EL element, and a display device.

An organic EL element has a structure in which an organic light emitting layer exhibiting at least an electroluminescence phenomenon is sandwiched between an electrode as an anode and an electrode as a cathode, and when a voltage is applied between the electrodes, This is a self-luminous element in which the organic light emitting layer emits light by injecting holes and electrons into the light emitting layer and recombining the holes and electrons in the organic light emitting layer.

Further, for the purpose of increasing luminous efficiency, a hole injection layer, a hole transport layer, an electron blocking layer, or a hole between the organic light emitting layer and the cathode is provided between the anode and the organic light emitting layer. A block layer, an electron transport layer, an electron injection layer, and the like are appropriately selected and provided. The organic light emitting layer and these hole injection layer, hole transport layer, electron block layer, hole block layer, electron transport layer, electron injection layer and the like are collectively referred to as a light emitting medium layer.

Each of these light emitting medium layers is made of an organic material or an inorganic material. Organic materials include low molecular weight materials and high molecular weight materials.

Examples of using low molecular weight materials include, for example, copper phthalocyanine (CuPc) for the hole injection layer and N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1 for the hole transport layer. , 1'-biphenyl-4,4'diamine (TPD), tris (8-quinolinol) aluminum (Alq3) for the organic light emitting layer, 2- (4-biphenylyl) -5- (4-tert-butyl for the electron transport layer -Phenyl) -1,3,4, -oxadizole (PBD), and those using LiF or the like for the electron injection layer.

Each of the light emitting medium layers made of these low molecular materials is generally about 0.1 to 200 nm in thickness, and mainly by a vacuum evaporation method such as a resistance heating method or a dry method (dry process) in a vacuum such as a sputtering method. A film is formed.

In addition, there are many types of low molecular weight materials, and combinations thereof are expected to improve luminous efficiency, luminous luminance, lifetime, and the like.

Examples of the polymer material include a material obtained by dissolving a low-molecular light-emitting pigment in a polymer such as polystyrene, polymethyl methacrylate, and polyvinyl carbazole in an organic light-emitting layer, or a polyphenylene vinylene derivative (hereinafter abbreviated as PPV). Polymer phosphors such as polyalkylfluorene derivatives (hereinafter abbreviated as PAF) and polymer phosphors such as rare earth metals are used.

These polymer materials are generally dissolved or dispersed in a solvent and formed into a film with a thickness of about 1 to 100 nm using a wet method such as coating or printing.

When using the wet method, it is possible to form a film in the atmosphere, the equipment is inexpensive, the size can be easily increased, and it is efficient in a short time compared to the case where a dry method in vacuum such as a vacuum deposition method is used. There is an advantage that a film can be formed.

In addition, organic thin films formed using high-molecular materials are less likely to crystallize and aggregate, and because they cover pinholes and foreign objects in other layers, they can prevent defects such as short circuits and dark spots. There is also.

On the other hand, as the inorganic material, the carrier transport layer includes an alkali metal element such as Li, Na, K, Rb, Ce, and Fr, an alkaline earth metal element such as Mg, Ca, Sr, and Ba, La, Ce, Lanthanoid elements such as Pr, Nd, Sm, Eu, Gd, Db, Dy, Ho, Er, Tm, Yb, Lu, actinoid elements such as Th, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Y, Ar, Nb, Mo, Ru, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Al, Ga, In, Sn, Tl, Pb, and Bi Metal elements such as B, Si, Ge, As, Sb, Te, and other inorganic compounds such as alloys, oxides, carbides, nitrides, borides, sulfides, and halides are used. It has been.

Many inorganic materials have higher adhesion and thermal stability than organic materials, and are expected to suppress false light emission due to leakage current, reduce non-light emitting areas called dark spots, and improve light emission characteristics and lifetime. The In addition, inorganic materials play an important role in terms of cost reduction when considering application to large displays and mass-produced products that are relatively inexpensive compared to organic materials.

A configuration is known in which an inorganic hole injection layer using an inorganic material is provided between an organic light emitting layer and an anode that is a hole injection electrode by utilizing this feature (Patent Document 1, Patent Document 3, and Patent Document). 4, Patent Document 5, Cited Document 6, Cited Document 7).

In addition, a configuration in which an inorganic electron injection layer using an inorganic material is provided between an organic light emitting layer and a cathode that is an electron injection electrode is known (Patent Document 2, Patent Document 3, Patent Document 4, and Cited Document 7).

Of these, molybdenum oxide, in particular, is easy to form, has a high hole injection function from the hole injection electrode, has an excellent function of stably transporting holes, and has a positive hole transport function. It is known that it is a material useful as a part of material and electron injection material.

By the way, molybdenum oxide is mainly classified into molybdenum trioxide (MoO ₃ ) and molybdenum dioxide (MoO ₂ ). Molybdenum trioxide is generally used because the transmittance during film formation is high for molybdenum trioxide and low for molybdenum dioxide.

However, since molybdenum trioxide is slightly soluble in water, it reacts with moisture after formation of molybdenum trioxide and its physical properties are likely to change. On the other hand, most of the molybdenum dioxide and other inorganic compounds are insoluble in water, so that changes in physical properties are unlikely to occur.

In particular, when the luminescent medium layer adjacent to molybdenum oxide includes manufacturing processes that come into contact with the atmosphere, such as transportation and film formation, the film deteriorates due to factors such as moisture in the atmosphere, and the luminous efficiency, luminescence brightness, lifetime, etc. There is a problem that display characteristics of the display deteriorate.

That is, when the luminescent medium layer is laminated only by the dry method in vacuum, the amount of deterioration factor adsorbed on the surface of the molybdenum trioxide layer is small and the influence is small, but the manufacturing process for forming a film in the atmosphere In the case of including, display characteristics may be significantly degraded.

In addition, when water-based, alcohol-based, ketone-based, carboxylic acid-based, nitrile-based, and ester-based solvents are used in the manufacturing process in which film formation is performed in the air, such as a wet method, molybdenum trioxide dissolves, and physical properties and films The thickness is changed, and in particular, there arises a problem that causes a decrease in luminous efficiency and luminous luminance.

Therefore, when molybdenum oxide is used, there is a concern about deterioration due to various deterioration factors, and a stable light emitting medium layer cannot be formed in all manufacturing processes.

Japanese Patent Laid-Open No. 11-307259 JP 2002-367784 A Japanese Patent Laid-Open No. 5-41285 JP 2000-68065 A JP 2000-215985 A JP 2006-114521 A JP 2006-155978 A

The present invention has been made in view of the above problems, and an object of the present invention is to provide an organic EL element having high light emission efficiency, high light emission luminance, long life, and no defects, in which the influence of deterioration factors is prevented. In addition, there is a manufacturing method capable of stably and efficiently producing an organic EL element having high light emission efficiency, high light emission luminance, long life, and no defects, in which the influence of deterioration factors is prevented in all the manufacturing processes. The issue is to provide. It is another object of the present invention to provide an inexpensive display device that has high light emission efficiency, high light emission luminance, long life, and no defects, in which the influence of deterioration factors is prevented.

The invention according to claim 1 includes a substrate, a first electrode provided on the substrate, a light emitting medium layer including at least an organic light emitting layer and a molybdenum oxide-containing layer provided on the first electrode, and the light emission. An organic electroluminescence device comprising: a second electrode facing the first electrode across a medium layer; and the molybdenum oxide-containing layer containing at least molybdenum trioxide and another inorganic compound. .

The invention according to claim 2 is the organic electroluminescence according to claim 1, wherein the molybdenum oxide-containing layer includes a layer in which a layer containing molybdenum trioxide and a layer containing another inorganic compound are stacked. It is an element.

The invention according to claim 3 is characterized in that the other inorganic compound is molybdenum dioxide, indium oxide, titanium oxide, iridium oxide, tantalum oxide, nickel oxide, tungsten oxide, vanadium oxide, tin oxide, lead oxide, niobium oxide, aluminum oxide, Copper oxide, manganese oxide, praseodymium oxide, chromium oxide, bismuth oxide, calcium oxide, barium oxide, cesium oxide, lithium fluoride, natrium fluoride, zinc selenide, zinc telluride, gallium nitride, gallium indium nitride, magnesium silver, 3. The organic electroluminescent element according to claim 1, wherein the organic electroluminescent element is any one of aluminum lithium and copper lithium.

The invention according to claim 4 is the organic electroluminescence element according to claim 2, wherein the layer containing molybdenum trioxide is a molybdenum trioxide layer.

The invention according to claim 5 is the organic electroluminescent element according to claim 2, wherein the film thickness of the layer containing the other inorganic compound is 5 nm or more and 30 nm or less.

The invention according to claim 6 is characterized in that the molybdenum oxide-containing layer is any one of a hole injection layer, a hole transport layer, and a hole injection transport layer. It is an organic electroluminescent element in any one.

The invention according to claim 7 is a substrate, a first electrode provided on the substrate, a light emitting medium layer including at least an organic light emitting layer and a molybdenum oxide-containing layer provided on the first electrode, and the light emission A method for producing an organic electroluminescent element having a second electrode facing the first electrode across a medium layer,
The method for producing an organic electroluminescence element is characterized in that the step of forming the molybdenum oxide-containing layer includes a step of simultaneously forming a film of at least molybdenum trioxide and another inorganic compound.

The invention according to claim 8 is a substrate, a first electrode provided on the substrate, a light emitting medium layer including at least an organic light emitting layer and a molybdenum oxide-containing layer provided on the first electrode, and the light emission A method for producing an organic electroluminescent element having a second electrode facing the first electrode across a medium layer,
The step of forming the molybdenum oxide-containing layer includes a step of forming a film of a first material containing at least molybdenum trioxide and a second material made of another inorganic compound in succession. It is a manufacturing method of an electroluminescent element.

The invention according to claim 9 is characterized in that the other inorganic compound is molybdenum dioxide, indium oxide, titanium oxide, iridium oxide, tantalum oxide, nickel oxide, tungsten oxide, vanadium oxide, tin oxide, lead oxide, niobium oxide, aluminum oxide, Copper oxide, manganese oxide, praseodymium oxide, chromium oxide, bismuth oxide, calcium oxide, barium oxide, cesium oxide, lithium fluoride, natrium fluoride, zinc selenide, zinc telluride, gallium nitride, gallium indium nitride, magnesium silver, 9. The method of manufacturing an organic electroluminescent element according to claim 7, wherein the method is any one of aluminum lithium and copper lithium.

The invention according to claim 10 is the method of manufacturing an organic electroluminescent element according to claim 8, wherein the first material is molybdenum trioxide.

The invention according to claim 11 is characterized in that the film thickness of the inorganic compound layer formed in the step of forming the second material made of the inorganic compound is 5 nm or more and 30 nm or less. It is a manufacturing method of the organic electroluminescent element of Claim 10.

The invention according to claim 12 includes a substrate, a first electrode provided on the substrate, a light emitting medium layer including at least an organic light emitting layer and a molybdenum oxide-containing layer provided on the first electrode, and the light emission. A method for producing an organic electroluminescent element having a second electrode facing the first electrode across a medium layer,
The method for producing an organic electroluminescence element is characterized in that the step of forming the molybdenum oxide-containing layer includes a step of etching the formed film surface after the step of forming molybdenum trioxide.

The invention according to claim 13 is the manufacturing of the organic electroluminescence element according to claim 12, wherein the molybdenum dioxide layer formed in the step of etching the film surface has a thickness of 5 nm or more and 20 nm or less. Is the method.

The invention according to claim 14 is characterized in that the film forming step is a step of forming a film by any one of a vapor deposition method, a sputtering method, and a CVD method. This is a method for producing an organic electroluminescence element.

The invention according to claim 15 is characterized in that the molybdenum oxide-containing layer is any one of a hole injection layer, a hole transport layer, and a hole injection transport layer. It is a manufacturing method of the organic electroluminescent element in any one.

The invention according to claim 16 is characterized in that the step of forming at least one of the light emitting medium layers adjacent to the molybdenum oxide-containing layer is a step of forming in the atmosphere. It is a manufacturing method of a crab organic electroluminescent element.

According to a seventeenth aspect of the present invention, in any one of the seventh to sixteenth aspects, the step of forming at least one of the light emitting medium layers adjacent to the molybdenum oxide-containing layer is a step of forming by a wet method. It is a manufacturing method of the organic electroluminescent element of a crab.

According to an eighteenth aspect of the present invention, in the step of forming the light emitting medium layer by a wet method, the solvent of the coating solution for the light emitting medium layer is water-based, alcohol-based, ketone-based, carboxylic acid-based, nitrile-based, ester-based, aromatic The method for producing an organic electroluminescent element according to claim 17, comprising at least one of a family.

The invention according to claim 19 is the method of manufacturing an organic electroluminescence element according to claim 17 or 18, wherein the wet method is a printing method.

The invention according to claim 20 is the method for producing an organic electroluminescence element according to claim 19, wherein the printing method is a relief printing method.

The invention according to claim 21 is a display device comprising the organic electroluminescence element according to any one of claims 1 to 6 as a display element.

According to the present invention, an organic EL element and a display device free from defects are provided by providing a molybdenum oxide-containing layer containing at least molybdenum trioxide and another inorganic compound. We were able to.

Furthermore, by including the process of simultaneously forming a film of molybdenum trioxide and other inorganic compounds, the influence of deterioration factors is prevented in all manufacturing processes, and high luminous efficiency, high luminous luminance, long life, and defects are prevented. It was possible to provide a production method capable of producing an organic EL device having no slag quickly, efficiently, and stably at low cost.

In addition, by including a step of forming a film of a first material containing molybdenum trioxide and a second material made of another inorganic compound, the influence of deterioration factor factors is prevented in all manufacturing steps. In addition, it has been possible to provide a production method capable of producing an organic EL element having high luminous efficiency, high luminous luminance, long life, and no defects quickly and efficiently at low cost.

Then, after the step of forming molybdenum trioxide, the step of etching the formed film surface is included, so that the influence of deterioration factor factors is prevented in all manufacturing steps, and high luminous efficiency, high luminous luminance, It was possible to provide a production method capable of producing an organic EL element having a long life and no defects quickly, efficiently, and stably at a low cost.

It is explanatory drawing which shows an example of the organic EL element of this invention. It is explanatory drawing which shows an example of the organic EL element of this invention. It is explanatory drawing which shows an example of the organic EL element of this invention. It is explanatory drawing which shows an example of the organic EL element of this invention. It is explanatory drawing which shows an example of the organic EL element of this invention. It is explanatory drawing which shows an example of the organic EL element of this invention. It is explanatory drawing which shows an example of the organic EL element of this invention. It is explanatory drawing which shows an example of the organic EL element of this invention. It is explanatory drawing which shows an example of the relief printing method of this invention. It is explanatory drawing which shows an example of the display apparatus of this invention. It is the figure which showed the transmittance | permeability change by the film thickness of molybdenum dioxide.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the drawings referred to in the following description of the embodiments are for explaining the configuration of the present invention, and the size, thickness, dimensions, and the like of each part illustrated are different from the actual ones. The present invention is not limited to these.

FIG. 1 shows an example of the organic EL element of the present invention. FIG. 1 is a schematic cross-sectional view.

In the case where the substrate 101 side is the display side, the substrate 101 can be a light-transmitting base material having a certain degree of strength. For example, a glass substrate or a plastic film or sheet can be used. If a thin glass substrate having a thickness of 0.2 to 1.0 mm is used, a thin organic EL element having a very high barrier property can be obtained.

As the first electrode 102, a conductive substance capable of forming a transparent or translucent electrode can be suitably used.

When the first electrode 102 is an anode, for example, a composite oxide of indium and tin (hereinafter abbreviated as ITO), a composite oxide of indium and zinc (hereinafter abbreviated as IZO), tin oxide, zinc oxide, and indium oxide And zinc aluminum composite oxide.

ITO can be preferably used because of its low resistance, solvent resistance, and high transparency, and can be formed on the substrate 101 by vapor deposition or sputtering.

Alternatively, a precursor such as indium octylate or indium acetone can be applied to the substrate 101 and then formed by an application pyrolysis method in which an oxide is formed by thermal decomposition. Alternatively, a metal such as aluminum, gold, or silver can be vapor-deposited in a translucent manner. Alternatively, an organic semiconductor such as polyaniline can also be used.

The first electrode 102 can be patterned by etching or the like as necessary. Further, the surface can be activated by UV treatment, plasma treatment, or the like.

The light emitting medium layer 103 is composed of a plurality of functional layers, for example, a hole injection layer, a hole transport layer, a hole injection transport layer, an electron blocking layer, an organic light emitting layer, a hole blocking layer, an electron transport layer, an electron. Examples thereof include an injection layer, an electron injection transport layer, and an insulating layer.

In order to obtain sufficient luminous efficiency, luminous luminance, and lifetime, a structure in which at least an organic light emitting layer and one or more other functional layers are laminated is preferable.

The functional layer includes a molybdenum oxide-containing layer containing at least molybdenum trioxide and other inorganic compounds, thereby providing an organic EL element and a display device having high luminous efficiency, high luminous luminance, long life, and no defects. can do.

Molybdenum oxides represented by MoO _X (x = 2 to ₃ ) and roughly divided into molybdenum trioxide (MoO ₃ ) and molybdenum dioxide (including MoO ₂ , 2 <x <3, the same applies hereinafter) Compared with organic materials, it has high adhesion and thermal stability, can suppress false light emission due to leakage current, and can reduce the occurrence of non-light-emitting areas called dark spots. And can improve the service life. In addition, since it is relatively inexpensive compared to organic materials, it plays an important role in terms of cost reduction when considering application to large display devices and mass-produced products.

In addition, it has a low boiling point (1155 ° C.) compared to other inorganic materials, facilitates film formation, has a high function of facilitating the injection of holes from the hole injection electrode, and a function of stably transporting holes. It is known to be a useful material such as being excellent.

Furthermore, in general, it is difficult to improve the flatness of a film formed by a wet method, but since a molybdenum oxide-containing layer is generally formed by a dry method, the flatness of the film is high. If the flatness is poor, the electric field concentrates at a thin film thickness, a non-light emitting portion is generated in the pixel, and a uniform light emitting surface cannot be obtained.

In particular, the apparent luminance in the display device is proportional to the light emission area in the pixel of the display device, and if the light emission area in the pixel is halved, the apparent luminance is also approximately halved. . Then, for example, when a display device having a normal light emission area in a pixel and a display device having a light emission area in a pixel half are manufactured, the luminance half-life time when the light emission is apparently the same luminance is generally a power. As a result, a display device having a half-pixel light-emitting area has an overwhelmingly shorter lifetime than a display device having a normal pixel-light-emitting area.

For example, polyethylene dioxythiophene, which is generally used as a polymer material for the hole injection layer, requires various devices to improve flatness, whereas when molybdenum oxide is formed by a dry method, A uniform light-emitting surface can be easily obtained, which is excellent in terms of high brightness, long life, and high uniformity.

By including at least molybdenum trioxide and other inorganic compounds in the molybdenum oxide-containing layer, while maintaining the excellent hole transport performance and high transparency of molybdenum trioxide, It is possible to suppress deterioration due to deterioration factors such as moisture, and to provide organic EL elements and display devices that have high light emission efficiency, high light emission luminance, long life, and no defects quickly, efficiently, and stably at low cost.
Other inorganic compounds include alkaline metal elements such as Li, Na, K, Rb, Ce, and Fr, alkaline earth metal elements such as Mg, Ca, Sr, and Ba, La, Ce, Pr, Nd, Sm, Lanthanoid elements such as Eu, Gd, Db, Dy, Ho, Er, Tm, Yb, Lu, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Y, Ar, Nb, Mo, Ru , Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Al, Ga, In, Sn, Tl, Pb, and Bi, and other metal elements, B, Si, Ge, As, It can be arbitrarily selected from alloys of metalloid elements such as Sb and Te, oxides, carbides, nitrides, borides, sulfides and halides.

Among these, oxides, nitrides, and alloys are preferable because they have high stability, high visible light transmittance, and can be formed through a simple process. Furthermore, aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), scandium oxide (Sc ₂ O ₃ ), titanium oxide (TiO, Ti ₂ O ₃ , TiO ₂ , TiOx (x = 1 to 2)), vanadium oxide _{(V 2 O 3, V 2} O 4, V 2 O 5, VOx (1.5~2)), chromium oxide _{(Cr 2 O 3, CrO 3} ), manganese oxide _(MnO, MnO _2, Mn 2 O ₃ , Mn ₃ O ₄ ), iron oxide (FeO, Fe ₂ O ₃ , Fe ₃ O ₄ ), cobalt oxide (CoO, Co ₃ O ₄ ), nickel oxide (NiO), copper oxide (Cu ₂ O, CuO) ), zinc oxide (ZnO), gallium oxide _{(Ga 2 O} 3), germanium _(GeO 2 dioxide), arsenic oxide _{(As 2 O} 3), yttrium oxide _{(Y 2 O} 3), zirconium oxide _(ZrO 2), Niobium _{(NbO, Nb 2 O 3,} NbO 2,), niobium pentoxide _{(Nb 2 O} 5), molybdenum dioxide _{(MoO 2, MoOx (2 <} x <3)), ruthenium oxide _(RuO 2), palladium oxide (PdO), silver oxide (Ag ₂ O), silver peroxide (Ag ₂ O ₂ ), cadmium oxide (CdO), indium oxide (InO, In ₂ O, In ₂ O ₃ ), tin oxide (SnO, SnO ₂₎ ), Antimony oxide (Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ ), tellurium oxide (TeO, TeO ₂ , TeO ₃ ), hafnium oxide (HfO ₂ ), tantalum oxide (TaO, Ta ₂ O ₅ , TaO _2), tungsten oxide _(WO 2, WO 3), rhenium oxide _{(ReO 2, Re 2 O 7} , ReO 3), osmium oxide _{(OsO 4, Os 2 O 4} ) Iridium _{(IrO 2, Ir 2 O 3} ), thallium oxide _{(Tl 2 O, Tl 2 O} 3), lead oxide _{(PbO, Pb 3 O 4,} Pb 2 O 3, PbO 2, PbOx (1 <x <2 )), Bismuth oxide (Bi ₂ O ₃ ), cerium oxide (CeO ₂ , Ce ₂ O ₃ ), praseodymium oxide (Pr ₂ O ₃ , Pr ₆ O 11, PrO ₂ , PrOx (1 <x <2)), oxidation Neodymium (Nd ₂ O ₃ ), samarium oxide (Sm ₂ O ₃ ), europium oxide (EuO, Eu ₂ O ₃ ), gadolinium oxide (Gd ₂ O ₃ ), terbium oxide (Tb ₂ O ₃ , Tb ₄ O ₇ , _{TbO 2, TbOx (x = 1.5~2} )), dysprosium oxide _{(Dy 2 O} 3), holmium oxide _{(Ho 2 O} 3), erbium oxide _{(Er 2 O} 3), thulium oxide (Tm ₂ O ₃ ), ytterbium oxide (Yb ₂ O ₃ ), lutetium oxide (Lu ₂ O ₃ ), thorium oxide (ThO ₂ ), gallium nitride (GaN), gallium indium nitride (GaInN), zinc selenium (ZnSe) A thin film such as magnesium silver (MgAg) is preferable because it is unlikely to deteriorate due to deterioration factors such as moisture in the atmosphere.

When the molybdenum oxide-containing layer is used for the hole transport layer, an inorganic compound having a hole transport property of 4.0 to 6.0 eV is preferable, and when used for the electron transport layer, the work function is 1.0 to 4 An inorganic compound having an electron transport property of 0.0 eV is preferable.

Therefore, molybdenum dioxide (MoO ₂ , MoOx (2 <x <3)), indium oxide (InO, In ₂ O, In ₂ O ₃ ), titanium oxide (TiO, Ti ₂ O ₃ , TiO ₂ , TiOx (1 < x <2)), iridium oxide (IrO ₂ , Ir ₂ O ₃ ), tantalum oxide (TaO, Ta ₂ O ₅ , TaO ₂ ), nickel oxide (NiO), tungsten oxide (WO ₂ , WO ₃ ), vanadium oxide _{(V 2 O 3, V 2} O 4, V 2 O 5, VOx (1.5~2)), tin oxide _(SnO, SnO 2), lead oxide _{(PbO, Pb 3 O 4,} Pb 2 O 3, PbO ₂ , PbOx (1 <x <2)), niobium oxide (NbO, Nb ₂ O ₃ , NbO ₂ ), aluminum oxide (Al ₂ O ₃ ), copper oxide (Cu ₂ O, CuO), manganese oxide ( MnO, M _{O 2, Mn 2 O 3,} Mn 3 O 4), praseodymium oxide _{(Pr 2 O 3, Pr 6} O 11, PrO 2, PrOx (1 <x <2)), chromium oxide _{(Cr 2} O _3, CrO 3 ), Bismuth oxide (Bi ₂ O ₃ ), calcium oxide (CaO), barium oxide (BaO), cesium oxide (Cs ₂ O), lithium fluoride (LiF), natrium fluoride (NaF), zinc selenide (SeZn) ), Zinc telluride (TeZn), gallium nitride (GaN), gallium indium nitride (GaInN), magnesium silver (MgAg), aluminum lithium (AlLi), and copper lithium (CuLi) are more preferable.

As a method for forming a film of an inorganic compound, a method of vapor deposition by resistance heating or electron beam (EB) in vacuum, a method of sputtering using a reactive gas such as Ar gas, O ₂ gas, or N ₂ gas, CVD method, etc. and so on.

In particular, when depositing molybdenum dioxide by sputtering, it can be formed by controlling sputtering parameters by reactive sputtering using a metal molybdenum target or molybdenum oxide target and O ₂ gas, which is the same as molybdenum trioxide. Since a target can be used, an organic EL element and an organic EL display device can be manufactured quickly and easily.

Furthermore, since the molybdenum dioxide film can be formed by performing Ar etching on the surface of the molybdenum trioxide film, the process is simple and excellent.

Here, the ionization potential of molybdenum trioxide is 5.7 eV to 6.0 eV, and the ionization potential of molybdenum dioxide is 5.3 eV to 5.5 eV.

It is preferable that the ionization potential of the molybdenum oxide-containing layer is appropriately selected from the inorganic compound and the content thereof in consideration of the ionization potential of a layer adjacent to the molybdenum oxide-containing layer and the carrier balance of holes and electrons by other light emitting medium layers.

For example, as shown in FIG. 1, when the molybdenum oxide-containing layer 104 is provided on the anode 102, the ionization potential is 4.0 eV to 6.0 eV in order to optimize the hole injection balance from the anode. Furthermore, 5.5 eV to 5.7 eV is preferable. For example, it can be realized by changing the ratio of molybdenum dioxide to molybdenum trioxide from 20% to 60%.

Furthermore, in order to control the ionization potential and conductivity, other organic materials or inorganic materials may be arbitrarily mixed in the molybdenum oxide-containing layer. In particular, when the molybdenum oxide-containing layer is used between the organic light emitting layer and the cathode, it is possible to mix alkali metal or alkaline earth metal such as lithium fluoride and lithium oxide, and salts and oxides thereof from the cathode. This is more preferable because the electron injection balance is optimized.

In FIG. 1, the light-emitting medium layer 103 is composed of a molybdenum oxide-containing layer 104, an electron block layer 103b, an organic light-emitting layer 103c, and an electron injection layer 103d on the anode 102. The layer configuration is arbitrarily selected. I can do it.

In FIG. 1, the molybdenum oxide-containing layer 104 is provided as a hole injection layer, but can be provided as an arbitrary layer. Furthermore, a plurality of molybdenum oxide-containing layers can be used as different functional layers.

FIG. 2 shows an example in which the molybdenum oxide-containing layer 104 ′ is provided as an electron injection layer, and FIG. 3 shows an example in which the molybdenum oxide-containing layers 104 and 104 ′ are provided as a hole injection layer and an electron injection layer, respectively.

When the molybdenum oxide-containing layer is provided as an electron injection layer, the work function is preferably 1.0 eV to 4.0 eV. For example, the ratio of lithium fluoride to molybdenum trioxide is preferably 40% or more and 90% or less in order to optimize the electron injection balance from the cathode.

In FIG. 4, a molybdenum oxide-containing layer 104 including a layer 104a containing molybdenum trioxide and a layer 104b containing another inorganic compound is provided as a hole injection layer and adjacent to the layer 104a containing molybdenum trioxide. An example in which a layer 104b containing another inorganic compound is provided as an upper layer, in FIG. 5, a molybdenum oxide-containing layer 104 composed of a layer containing molybdenum trioxide and a layer containing another inorganic compound is provided as a hole injection layer. In addition, an example is shown in which layers 104b and 104b ′ containing other inorganic compounds are provided on the upper layer and the lower layer adjacent to the layer 104a containing molybdenum trioxide, respectively.

In FIG. 6, a molybdenum oxide-containing layer 104 ′ including a layer 104a ′ containing molybdenum trioxide and a layer 104c containing another inorganic compound is provided as an electron injection layer, and the layer 104a ′ containing molybdenum trioxide is provided. An example in which a layer 104c containing another inorganic compound is provided in an adjacent lower layer, FIG. 7 shows a molybdenum oxide-containing layer 104 ′ composed of a layer 104a ′ containing molybdenum trioxide and layers 104c and 104c ′ containing other inorganic compounds. In the example, layers 104c and 104c ′ including other inorganic compounds are provided as lower and upper layers adjacent to the layer 104a ′ including molybdenum trioxide and provided as an electron injection layer.

  In FIG. 8, molybdenum oxide-containing layers 104 and 104 ′ composed of a layer containing molybdenum trioxide and a layer containing another inorganic compound are provided as a hole injection layer and an electron injection layer, respectively. 104a, and layers 104b and 104b ′ containing other inorganic compounds are respectively provided in the upper layer and the lower layer adjacent thereto, and the latter is provided in the layer 104a ′ including molybdenum trioxide and the lower layer and the upper layer adjacent thereto, respectively. An example in which layers 104c and 104c ′ containing other inorganic compounds are provided is shown.

The film thickness of the molybdenum oxide-containing layers 104 and 104 ′ as shown in FIG. 1, FIG. 2, or FIG. 3 is arbitrary, but preferably 0.1 nm to 200 nm, and 0.1 to 100 nm. It is more preferable because it is possible to prevent an increase in the temperature. If it is too thick, the efficiency drop due to the voltage drop and the transmittance drop cannot be ignored. If it is too thin, the effects of carrier injection and transport are reduced, so that a voltage drop occurs in any case. In particular, in the case of a highly insulating material, a good injectability and transportability can be obtained by forming the film thickness in the range of 0.1 to 10 nm.

The molybdenum oxide-containing layers 104 and 104 ′ in FIG. 1, FIG. 2, and FIG. 3 are layers in which, for example, at least another inorganic compound and molybdenum trioxide are simultaneously formed, thereby mixing molybdenum trioxide and other inorganic compounds. Can be obtained as As a film formation method, there are a method of vapor deposition by resistance heating or electron beam (EB) in a vacuum, a method by sputtering using a reactive gas such as Ar gas and O 2 gas or N 2 gas, or CVD method.

In addition, an inorganic material or an organic material other than the inorganic compound may be appropriately mixed with the molybdenum oxide-containing layer by a similar method. When the molybdenum oxide-containing layer is a hole injection layer, examples of the inorganic material include lanthanoids such as La, Ce, Pr, Nd, Sm, Eu, Gd, Db, Dy, Ho, Er, Tm, Yb, and Lu. Elements, actinide elements such as Th, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Y, Ar, Nb, Mo, Ru, Pd, Ag, Cd, Hf, Ta, W, Re Metal elements such as Os, Ir, Pt, Au, Al, Ga, In, Sn, Tl, Pb, and Bi, metalloid elements such as B, Si, Ge, As, Sb, and Te, and organic materials include Low molecular weight materials include copper phthalocyanine and its derivatives, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N, N'-diphenyl-N, N'-bis (3-methylphenyl)- 1,1'-bi Eniru -4,4'diamine (TPD) vacuum deposition method, such as an aromatic amine such as resistance heating evaporation method such as electron beam method, a sputtering method, can be suitably mixed by a CVD method or the like. When the molybdenum oxide-containing layer is an electron injection layer, for example, inorganic materials include alkali metal elements such as Li, Na, K, Rb, Ce, and Fr, and alkaline earth metals such as Mg, Ca, Sr, and Ba Element, La, Ce, Pr, Nd, Sm, Eu, Gd, Db, Dy, Ho, Er, Tm, Yb, Lu and other lanthanoid elements, Th and actinoid elements, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Y, Ar, Nb, Mo, Ru, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Al, Ga, In, Sn, Metal elements such as Tl, Pb and Bi, metalloid elements such as B, Si, Ge, As, Sb and Te, and organic materials include triazole, oxazole, oxadiazole, silole, and boron A vacuum evaporation method such as a resistance heating evaporation method or the like, electron beam method, sputtering method, CVD method, or the like, in can be suitably mixed.

The layers 104a and 104a ′ containing molybdenum trioxide shown in FIGS. 4 to 8 are formed by a method in which at least molybdenum trioxide is deposited by resistance heating or electron beam (EB) in a vacuum, or sputtering using Ar gas and O ₂ gas. And a method such as a CVD method.

In addition, an inorganic material or an organic material other than the inorganic compound may be appropriately mixed with the layer containing molybdenum trioxide by a similar method. When the molybdenum oxide-containing layer is a hole injection layer, examples of the inorganic material include lanthanoids such as La, Ce, Pr, Nd, Sm, Eu, Gd, Db, Dy, Ho, Er, Tm, Yb, and Lu. Elements, actinide elements such as Th, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Y, Ar, Nb, Mo, Ru, Pd, Ag, Cd, Hf, Ta, W, Re Metal elements such as Os, Ir, Pt, Au, Al, Ga, In, Sn, Tl, Pb, and Bi, metalloid elements such as B, Si, Ge, As, Sb, and Te, and organic materials include Low molecular weight materials include copper phthalocyanine and its derivatives, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N, N'-diphenyl-N, N'-bis (3-methylphenyl)- 1,1'-bi Eniru -4,4 'method for depositing such diamine (TPD) aromatic amine, such as in a vacuum by resistive heating or EB or the method according to the sputtering, can be mixed suitably by CVD method or the like. When the molybdenum oxide-containing layer is an electron injection layer, for example, inorganic materials include alkali metal elements such as Li, Na, K, Rb, Ce, and Fr, and alkaline earth metals such as Mg, Ca, Sr, and Ba Element, La, Ce, Pr, Nd, Sm, Eu, Gd, Db, Dy, Ho, Er, Tm, Yb, Lu and other lanthanoid elements, Th and actinoid elements, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Y, Ar, Nb, Mo, Ru, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Al, Ga, In, Sn, Metal elements such as Tl, Pb and Bi, metalloid elements such as B, Si, Ge, As, Sb and Te, and organic materials include triazole, oxazole, oxadiazole, silole, and boron It can be suitably mixed method deposited by resistance heating and EB in vacuum or method by a sputtering, by CVD method or the like or the like.

The layers 104b, 104b ′, 104c, and 104c ′ containing other inorganic compounds are deposited by resistance heating or electron beam (EB) in vacuum, or reactive gases such as Ar gas, O ₂ gas, and N ₂ gas. It can be obtained by a sputtering method using CVD or a CVD method.

Furthermore, there is a method in which the surface of the molybdenum trioxide layer is changed to a molybdenum dioxide layer by etching using Ar or O ₂ gas after forming the molybdenum trioxide layer.

It is known that when the etching is performed with Ar or O ₂ gas after forming the molybdenum trioxide layer, the composition changes, and x of the molybdenum oxide MoOx becomes 2 to 3 or a mixture thereof depending on conditions (Journal of Electron Spectroscopy and Related Phenomena, 5 (1974) 351-367). Since these can be confirmed by composition analysis such as X-ray photoelectron spectroscopy, molybdenum dioxide can be formed by etching under conditions where x is 2. Here, etching refers to a phenomenon in which the sample surface is scraped by charging Ar or O ₂ gas with thermionic electrons, accelerating with a high voltage and colliding with the sample surface. In particular, in the case of molybdenum oxide, since oxygen atoms are more easily etched than molybdenum atoms, it is considered that the composition changes such that x of MoOx is 2 to 3 at the same time as the surface is scraped.

Such a phenomenon is caused by Au ₂ O ₃ , Ag ₂ O, Ag ₂ O ₂ , PdO, CuO, Cu ₂ O, IrO ₂ , PbO, NiO, PbO ₂ , CdO, FeO, RuO ₂ , WO ₂ , WO _3. , Fe ₂ O ₃ , and Fe ₂ O ₃ are also generated. Therefore, after forming these inorganic compound layers, the composition may be changed by the same method.

The film thickness of the molybdenum trioxide layer is arbitrary, but is preferably 5 nm or more and 100 nm or less.

The thickness of the layer containing another inorganic compound is arbitrary, but is preferably 0.5 nm or more and 70 nm or less. If it exceeds 70 nm, characteristics such as voltage drop and transmittance decrease occur. If it is thinner than 0.5 nm, the influence of the deterioration factor cannot be suppressed. Furthermore, the film thickness is preferably in the range of 5 nm or more and 30 nm or less in order to achieve both the suppression of the voltage drop and the decrease in the transmittance and the sufficient securing of the barrier property against the deterioration factor.

Considering the emission spectrum of the organic EL element, the transmittance is evaluated in the visible light region having a wavelength of 380 nm or more and 800 nm or less. Transmittance is very important because it affects the luminance of the emitted light, and thus greatly affects the luminance half-life. In consideration of these, the transmittance of the layer containing another inorganic compound is desirably at least 70% in the visible light wavelength region.

  FIG. 12 shows the results obtained by measuring the transmittance of a sample having a film thickness of 20 nm deposited on another glass with a vacuum vapor deposition method using a microscopic spectrophotometer (FA310A) manufactured by Toshiba. At a film thickness of 20 nm, the transmittance is about 70% or more in the visible light region, whereas at 50 nm, it is 60% or more.

The transmittance of the entire molybdenum oxide-containing layer is desirably at least 60% or more in the visible light wavelength region.

Here, the high transmittance of the molybdenum oxide-containing layer is effective when the molybdenum oxide-containing layer 104 is closer to the substrate 101 that extracts light than the organic light-emitting layer 103c, as shown in FIG. That is, for example, when the structure is as shown in FIG. 2 and the substrate 101 side is the display side, the transmittance of the molybdenum oxide-containing layer 104 ′ can be arbitrary.

On the other hand, as a material other than molybdenum oxide that can be used for the hole injection layer, the hole transport layer, and the hole injection transport layer, those generally used as a hole transport material can be preferably used, For example, low molecular weight materials include copper phthalocyanine and its derivatives, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N, N′-diphenyl-N, N′-bis (3-methylphenyl) ) -1,1′-biphenyl-4,4′diamine (TPD) and the like, and the like, and film formation is possible by a dry method such as vacuum deposition in vacuum.

In addition, these materials are toluene, xylene, acetone, anisole, methyl anisole, dimethyl anisole, ethyl benzoate, methyl benzoate, mesitylene, tetralin, amylbenzene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, isopropyl alcohol, If it is used as a hole injection coating solution, a hole transport coating solution, or a hole injection transport coating solution by dissolving or dispersing in ethyl acetate, butyl acetate, water or the like alone or in a mixed solvent, the film is formed by a wet method in air Is possible.

Examples of the polymer material include polyaniline, polythiophene, polyvinyl carbazole, a mixture of poly (3,4-ethylenedioxythiophene) and polystyrene sulfonic acid, a PPV derivative, and a PAF derivative. These hole injecting materials and hole transporting materials are dissolved in a single or mixed solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, isopropyl alcohol, ethyl acetate, butyl acetate, and water. It can be dispersed to form a hole injection coating solution, a hole transport coating solution, and a hole injection transport coating solution, and film formation by a wet method in the atmosphere is possible.

Here, among the above solvents, a hole injection layer, a hole transport layer, and a hole injection transport layer formed using an aqueous system, an alcohol system, a ketone system, a carboxylic acid system, a nitrile system, an ester system, and an aromatic system, in particular. Even when the molybdenum oxide-containing layer is adjacent, if the molybdenum oxide-containing layer is a structure of the present invention, a stable structure can be maintained without changing the physical properties and film thickness of the molybdenum oxide-containing layer.

Furthermore, lanthanoid elements such as La, Ce, Pr, Nd, Sm, Eu, Gd, Db, Dy, Ho, Er, Tm, Yb, and Lu, actinoid elements such as Th, Sc, Ti, V , Cr, Fe, Co, Ni, Cu, Zn, Y, Ar, Nb, Mo, Ru, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, Pt, Au, Al, Ga, In , Sn, Tl, Pb, Bi and other metal elements, B, Si, Ge, As, Sb, Te, and other metal elements, and alloys, oxides, carbides, nitrides, borides, sulfides Inorganic materials such as halides can also be formed by vapor deposition, sputtering, CVD, or the like.

As an electron block material used for the electron block layer 103b, OXD-1, PBD, BCP, Alq3, 3- (4-biphenylyl) -5- (4-tert-butylphenyl) -4-phenyl-1,2,4 -Triazole (also referred to as TAZ), 4,4'-bis (1,1-diphenylethenyl) biphenyl (also referred to as DPVBi), 2,5-bis (1-naphthyl) -1.3.4-oxa Diazole (also referred to as BND) 4,4′-bis (1,1-bis (4-methylphenyl) ethenyl) biphenyl (also referred to as DTVBi), 2,5-bis (4-biphenylyl) -1,3 , 4-oxadiazole (also referred to as BBD), oxadiazole polymer compounds, triazole polymer compounds, and the like.

As the organic light emitting material used for the organic light emitting layer 103c, those generally used as an organic light emitting material can be preferably used. Coumarin-based, perylene-based, pyran-based, anthrone-based, porphyrene-based, quinacridone-based, N , N′-dialkyl-substituted quinacridone, naphthalimide, N, N′-diaryl-substituted pyrrolopyrrole, etc., known fluorescent low molecular weight materials capable of emitting light from a singlet state, and triplet states of rare earth metal complexes The known phosphorescent low molecular weight materials capable of emitting light from the above can be mentioned, and these can be formed by a dry method such as a vacuum deposition method in a vacuum.

In addition, these materials are toluene, xylene, acetone, anisole, methyl anisole, dimethyl anisole, ethyl benzoate, methyl benzoate, mesitylene, tetralin, amylbenzene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, isopropyl alcohol, If it is used as an organic light emitting coating solution by dissolving or dispersing in ethyl acetate, butyl acetate, water or the like alone or in a mixed solvent, film formation by a wet method in the atmosphere is possible.

Polymeric materials include coumarin, perylene, pyran, anthrone, porphyrene, quinacridone, N, N'-dialkyl substituted quinacridone, naphthalimide, N, N'-diaryl substituted pyrrolopyrrole. Fluorescent dyes such as polystyrene, polymethyl methacrylate, polyvinyl carbazole, etc., polymer fluorescent phosphors such as PPV and PAF, and polymer phosphorescence containing rare earth metal complexes A polymer light emitter such as a body can be used.

These polymeric materials are toluene, xylene, acetone, anisole, methylanisole, dimethylanisole, ethyl benzoate, methyl benzoate, mesitylene, tetralin, amylbenzene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methanol, ethanol, isopropyl alcohol, A film can be formed by a wet method in the atmosphere as an organic light emitting coating solution by dissolving or dispersing in ethyl acetate, butyl acetate, water or the like alone or in a mixed solvent.

In particular, aromatic solvents such as toluene, xylene, anisole, methylanisole, dimethylanisole, ethyl benzoate, methylbenzoate, mesitylene, tetralin, and amylbenzene have good solubility in polymer materials and are easy to handle. Is more preferable.

Among the above solvents, when a molybdenum oxide-containing layer is adjacent to an organic light emitting layer formed using a particularly polar solvent such as water, alcohol, ketone, carboxylic acid, nitrile, ester, or aromatic. However, if the molybdenum oxide-containing layer has the structure of the present invention, a stable structure can be maintained without changing the physical properties and film thickness of the molybdenum oxide-containing layer.

And as materials other than molybdenum oxide that can be used for the electron injection layer 103d, alkali metals such as lithium fluoride and barium oxide, alkaline earth metals, and salts and oxides thereof can be preferably used. Film formation by a dry method such as vacuum deposition in vacuum is possible.

The thickness of each layer of the luminescent medium layer is arbitrary, but is preferably 0.1 to 200 nm.

When the second electrode 105 is a cathode, a single metal such as Mg, Al, Yb, or an alloy system of a metal having a low work function and a stable metal capable of achieving both electron injection efficiency and stability, for example, MgAg Alloys such as AlLi and CuLi can be used.

As a method for forming the cathode, a vacuum evaporation method such as a resistance heating evaporation method, an electron beam method, a sputtering method, or the like can be used depending on the material. The thickness of the cathode is preferably about 10 nm to 1000 nm.

In FIG. 1, the substrate 101 is laminated from an electrode as an anode, but lamination from an electrode as a cathode is also possible as appropriate.

In FIG. 1, the substrate 101 side is the display side, but display from the opposite side to the substrate 101 side is also possible as appropriate.

And the organic electroluminescent element of this invention can form at least one of the luminescent medium layer adjacent to the molybdenum oxide containing layer containing at least molybdenum trioxide and another inorganic compound in air | atmosphere.

For example, even if the light emitting medium layer adjacent to the upper side of the molybdenum oxide-containing layer 104 in FIG. 1 is formed in the atmosphere, the molybdenum oxide-containing layer 104 contains other inorganic compounds, thereby deteriorating moisture and the like in the atmosphere. It is possible to manufacture an organic electroluminescent element that is efficient in the manufacturing process, in which the deterioration due to the deterioration factor of the molybdenum oxide-containing layer 104 due to the factor is prevented.

Further, for example, even when the light emitting medium layer adjacent to the lower part of the molybdenum oxide-containing layer 104 ′ in FIG. 2 is formed in the atmosphere, it contains other inorganic compounds, so that moisture in the atmosphere remaining in the lower layer can be reduced. An organic electroluminescence element with an efficient manufacturing process in which deterioration of the molybdenum oxide-containing layer due to a deterioration factor is prevented can be manufactured.

Further, for example, even if the light emitting medium layer adjacent above the molybdenum oxide-containing layer 104 and the light emitting medium layer adjacent below the molybdenum oxide-containing layer 104 ′ in FIG. Thus, it is possible to manufacture an organic electroluminescence device with an efficient manufacturing process in which the deterioration of the molybdenum oxide-containing layers 104 and 104 ′ due to the deterioration factor is prevented.

For example, in the case where the light emitting medium layer adjacent to the upper side of the molybdenum oxide-containing layer 104 in which the layer 104b containing another inorganic compound is formed above the layer 104a containing molybdenum trioxide in FIG. 4 is formed in the atmosphere. However, it is possible to manufacture an organic electroluminescence element with an efficient manufacturing process in which deterioration of the molybdenum oxide-containing layer 104 due to deterioration factors such as moisture in the atmosphere is prevented.

Further, for example, the molybdenum oxide-containing layer 104 in which a layer 104b containing another inorganic compound and a layer 104b ′ containing another inorganic compound are formed above and below the layer 104a containing molybdenum trioxide in FIG. Even when the light emitting medium layer adjacent to the upper side is formed in the air, the deterioration of the molybdenum oxide-containing layer 104 due to deterioration factors such as moisture in the air is prevented, and an organic electroluminescence device with an efficient manufacturing process is manufactured. be able to. Furthermore, deterioration factor factors from the substrate 101 and the first electrode 102 are also prevented.

Further, for example, a light emitting medium layer adjacent to the lower side of the molybdenum oxide-containing layer 104 in which the layer 104a ′ containing molybdenum trioxide is formed above the layer 104c containing another inorganic compound in FIG. 6 is formed in the atmosphere. Even in this case, it is possible to manufacture an organic electroluminescence element that is efficient in the manufacturing process, in which deterioration of the molybdenum oxide-containing layer 104 due to deterioration factors such as moisture in the atmosphere is prevented.

Further, for example, the molybdenum oxide-containing layer 104 in which a layer 104c containing another inorganic compound and a layer 104c ′ containing another inorganic compound are formed below and above the layer 104a ′ containing molybdenum trioxide in FIG. 7, respectively. An organic electroluminescence device with an efficient manufacturing process in which deterioration of the molybdenum oxide-containing layer 104 due to deterioration factors such as moisture in the atmosphere is prevented even when the light emitting medium layer adjacent below is formed in the air. Can be manufactured.

Also, for example, above the molybdenum oxide-containing layer 104 in which a layer 104b containing another inorganic compound and a layer 104b ′ containing another inorganic compound are formed above and below the layer 104a containing molybdenum trioxide in FIG. 8, respectively. And under the molybdenum oxide-containing layer 104 ′ where the layer 104c containing another inorganic compound and the layer 104c ′ containing another inorganic compound are formed below and above the layer 104a ′ containing molybdenum trioxide, respectively. Even when the adjacent light-emitting medium layer is formed in the air, an organic electroluminescence device with an efficient manufacturing process in which the deterioration of the molybdenum oxide-containing layers 104 and 104 ′ due to deterioration factors such as moisture in the air is prevented. Can be manufactured.

Furthermore, in the organic electroluminescence element of the present invention, at least one of the light emitting medium layers adjacent to the molybdenum oxide-containing layer containing at least molybdenum trioxide and another inorganic compound can be formed by a wet method.

For example, even if the light emitting medium layer adjacent to the upper side of the molybdenum oxide-containing layer 104 in FIG. 1 is formed by a wet method, the molybdenum oxide-containing layer 104 due to a deterioration factor such as a solvent is contained by containing another inorganic compound. It is possible to manufacture an organic electroluminescence element that is prevented from being deteriorated by a deterioration factor and that is efficient in the manufacturing process.

Further, for example, even when the light emitting medium layer adjacent to the lower part of the molybdenum oxide-containing layer 104 in FIG. 2 is formed by a wet method, it contains other inorganic compounds, thereby causing deterioration factors such as a solvent remaining in the lower layer. An organic electroluminescence element with an efficient manufacturing process in which deterioration of the molybdenum oxide-containing layer 104 is prevented can be manufactured.

Further, for example, even if the light emitting medium layer adjacent above the molybdenum oxide-containing layer 104 and the light emitting medium layer adjacent below the molybdenum oxide-containing layer 104 ′ in FIG. An organic electroluminescence device with an efficient manufacturing process in which deterioration of the molybdenum oxide-containing layers 104 and 104 ′ due to factors is prevented can be manufactured.

Further, for example, a light emitting medium layer adjacent to the upper side of the molybdenum oxide-containing layer 104 in which the layer 104b containing another inorganic compound is formed above the layer 104a containing molybdenum trioxide in FIG. 4 is formed by a wet method. In addition, it is possible to manufacture an organic electroluminescence element with an efficient manufacturing process in which deterioration of the molybdenum oxide-containing layer 104 due to a deterioration factor such as a solvent is prevented.

Further, for example, the molybdenum oxide-containing layer 104 in which a layer 104b containing another inorganic compound and a layer 104b ′ containing another inorganic compound are formed above and below the layer 104a containing molybdenum trioxide in FIG. It is possible to manufacture an organic electroluminescence device with an efficient manufacturing process in which deterioration of the molybdenum oxide-containing layer 104 due to a deterioration factor such as a solvent is prevented even if a light emitting medium layer adjacent to the upper side is formed by a wet method. it can. Furthermore, deterioration factor factors from the substrate 101 and the first electrode 102 are also prevented.

Further, for example, a light emitting medium layer adjacent to the lower side of the molybdenum oxide-containing layer 104 in which the layer 104a containing molybdenum trioxide is formed above the layer 104c containing another inorganic compound in FIG. 6 is formed by a wet method. In addition, it is possible to manufacture an organic electroluminescence element with an efficient manufacturing process in which deterioration of the molybdenum oxide-containing layer 104 due to a deterioration factor such as a solvent is prevented.

Further, for example, a molybdenum oxide-containing layer 104 ′ in which a layer 104c containing another inorganic compound and a layer 104c ′ containing another inorganic compound are formed below and above the layer 104a ′ containing molybdenum trioxide in FIG. 7, respectively. Even if the lower light emitting medium layer is formed by a wet method, an organic electroluminescence device with an efficient manufacturing process in which deterioration of the molybdenum oxide-containing layer 104 due to a deterioration factor such as a solvent is prevented is manufactured. be able to.

Also, for example, above the molybdenum oxide-containing layer 104 in which a layer 104b containing another inorganic compound and a layer 104b ′ containing another inorganic compound are formed above and below the layer 104a containing molybdenum trioxide in FIG. 8, respectively. And under the molybdenum oxide-containing layer 104 ′ where the layer 104c containing another inorganic compound and the layer 104c ′ containing another inorganic compound are formed below and above the layer 104a ′ containing molybdenum trioxide, respectively. To manufacture an organic electroluminescence device with an efficient manufacturing process in which deterioration of molybdenum oxide-containing layers 104 and 104 ′ due to deterioration factors such as a solvent is prevented even when adjacent light emitting medium layers are formed by a wet method. Can do.

Examples of the wet method include a coating method and a printing method, and a spin coater, a bar coater, a roll coater, a die coater, a gravure coater, or the like can be suitably used as the coating method.

Furthermore, a printing method that can easily form a pattern directly can be suitably used.

Therefore, when the light emitting medium layer is formed by a wet method, a known printing method such as a relief printing method, an intaglio printing method, a screen printing method, a gravure printing method, a flexographic printing method, and an offset printing method is preferably used. Can be used.

In particular, the relief printing method is suitable for the production of organic EL elements from the point that the viscosity characteristics of the coating liquid are in a good viscosity range, can be printed without damaging the substrate, and the utilization efficiency of the coating liquid material is good. Yes.

FIG. 9 shows an example of the relief printing method of the present invention. FIG. 9 shows an outline of the relief printing method when pattern-printing the coating liquid made of the material of the light emitting medium layer on the printed substrate 201 on which electrodes and the like are formed.

This relief printing method includes an ink tank 202, an ink chamber 203, an anilox roll 204, and a plate cylinder 206 on which a plate 205 provided with a convex portion is mounted. The ink tank 202 contains a coating liquid made of the material of the light emitting medium layer, and the coating liquid can be fed into the ink chamber 203 from the ink tank 202. In addition, the anilox roll 204 is rotatably supported in contact with the coating liquid supply unit of the ink chamber 203.

Along with the rotation of the anilox roll 204, the coating layer 204a of the coating liquid supplied to the anilox roll surface is formed with a uniform film thickness. The coating layer 204 a is transferred to the convex portion of the plate 205 mounted on the plate cylinder 206 that is driven to rotate in the vicinity of the anilox roll 204.

Further, the printing substrate 201 is transported to the flat table 207 by a transport means (not shown) up to the printing position by the convex portion of the plate 205. The ink on the convex portion of the plate 205 is printed on the printing substrate 201, and a light emitting medium layer can be suitably formed on the printing substrate 201 through a drying process as necessary. it can.

As the plate 205 provided with the relief plate, a known one can be suitably used, but a photosensitive resin relief plate is preferred. There are two types of photosensitive resin relief plates: a solvent development type in which the developer used for developing the exposed resin plate is an organic solvent and a water development type in which the developer is water. Resistant to water-based inks, and those of the water development type are resistant to organic solvent-based inks. A solvent development type and a water development type can be suitably selected according to the characteristics of the coating solution made of the material of the light emitting medium layer.

In the organic EL element shown in FIG. 1, for example, after the molybdenum oxide-containing layer 104 is provided in a vacuum as a hole injection layer, the electron blocking layer 103b and the organic light emitting layer 103c are formed in the atmosphere by a relief printing method. The electron injection layer 103d can be formed and manufactured in a vacuum.

Further, after the organic EL element shown in FIG. 2 is formed, for example, after the hole injection layer 103a and the electron blocking layer 103b are provided in a vacuum, the organic light emitting layer 103c is formed using a relief printing method in the atmosphere. It is also possible to manufacture by suitably combining the formation of the luminescent medium layer in vacuum and the formation of the luminescent medium layer in the atmosphere, such as forming the molybdenum oxide-containing layer 104 as an electron injection layer in vacuum. is there.

Next, an example of a passive matrix type display device using the organic EL element of the present invention is shown in FIG. FIG. 10 is a schematic cross-sectional view.

When the substrate 301 side is the display side, the first electrode 302 as a line-shaped transparent or translucent anode is suitably formed, and then, if necessary, a photolithographic material is used between adjacent electrodes using, for example, a photosensitive material. The insulating layer 306 can be formed by a known method such as a method.

By providing the insulating layer 306 between adjacent electrodes, it is possible to suppress the spread of the coating liquid made of the material of the luminescent medium layer applied on each electrode.

In particular, it is possible to prevent color mixing when a light emitting medium layer having a plurality of colors is formed.

As the photosensitive material for forming the insulating layer 306, a positive resist, a negative resist, or the like can be preferably used. Examples of the insulating material include polyimide, acrylic resin, and novolac resin.

In order to improve display characteristics, a light-shielding material can be included in the photosensitive material. Furthermore, in order to prevent the coating liquid from spreading to the insulating layer, a liquid repellent material can be contained in the photosensitive material.

The photosensitive resin for forming the insulating layer 306 can be applied by a coating method such as a spin coater, a bar coater, a roll coater, a die coater, or a gravure coater, and can be patterned by a photolithography method or the like.

When a spin coater is used, a coating film having a desired film thickness may not be obtained by one coating. In this case, a desired film thickness can be obtained by repeating the same process a plurality of times. .

If necessary, the formed insulating layer 306 can be subjected to treatment such as plasma cleaning or UV cleaning to adjust the surface to liquid repellency.

After the insulating layer 306 is formed, for example, the molybdenum oxide-containing layer 304 is formed in a vacuum, and the electron block layer 303b and the organic light emitting layer 303c are formed in the atmosphere using a relief printing method. Thus, the electron injection layer 303d can be formed.

Here, FIG. 10 illustrates an example in which the molybdenum oxide-containing layer 304 is provided between the partition walls. However, if the electrical characteristics of the molybdenum oxide-containing layer are sufficiently controlled, as illustrated in FIG. It can also be formed over.

When the molybdenum oxide-containing layer 304 is provided between the partition walls, charge leakage between the molybdenum oxide-containing layers 304 can be reliably prevented. On the other hand, when the molybdenum oxide-containing layer 304 is provided so as to cover between the partition walls and the entire partition walls, use of a mask, a photolithography process, and the like can be omitted, and the efficiency of the manufacturing process is improved.

In FIG. 10, the light emitting medium layer 303 includes an electron block layer 303b, an organic light emitting layer 303c, and an electron injection layer 303d, but the layer configuration can be arbitrarily selected.

In FIG. 10, the molybdenum oxide-containing layer 304 is provided as a hole injection layer, but can be provided as an arbitrary layer. Furthermore, a plurality of molybdenum oxide-containing layers can be provided as a plurality of different functional layers.

In FIG. 10, the electron blocking layer 303b and the organic light emitting layer 303c are formed in the atmosphere. However, the hole injection layer 303a, the electron blocking layer 303b, and the organic light emitting layer 303d are formed using the relief printing method in the air. Thereafter, the formation of the light-emitting medium layer in vacuum and the formation of the light-emitting medium layer in the air can be suitably combined, such as forming the molybdenum oxide-containing layer 304 in a vacuum.

Then, the second electrode 305 as a line-shaped cathode can be suitably formed so as to be orthogonal to the first electrode 302.

In FIG. 10, the substrate 301 is stacked from an electrode as an anode, but stacking from an electrode as a cathode is also possible as appropriate.

In FIG. 10, the substrate 301 side is the display side, but display from the opposite side to the substrate 301 side is also possible as appropriate.

Further, in FIG. 10, a display device of a passive matrix type driving method using line electrodes is illustrated, but a known driving method such as a segment type using arbitrary pattern electrodes, an active matrix type using pixel electrodes or thin film transistors, etc. A method can be suitably selected.

Further, if necessary, in order to protect the organic EL element thus manufactured from external oxygen and moisture, for example, a glass cap and an adhesive may be hermetically sealed to form a display device. . Further, in the case where the substrate has flexibility, a sealing device and a flexible film can be used for hermetically sealing to form a display device.

Example 1
First, a glass substrate having a thickness of 0.7 mm and a diagonal size of 1.8 inches is used as a substrate, and ITO is used as an anode material on this substrate, and an ITO film is formed in a vacuum using a sputtering method. Then, the ITO film was patterned by photolithography and etching with an acid solution to provide a line electrode. As the line pattern, 192 lines were formed with a line width of 136 μm and a space of 30 μm.

Next, an acrylic photoresist material was spin coated on the entire surface of the glass substrate on which the line electrode was formed as an insulating layer material. The spin coating conditions were rotated at 150 rpm for 5 seconds, and then rotated at 500 rpm for 20 seconds to obtain a coating film having a height of 1.5 μm. Thereafter, a line-shaped insulating layer was formed between the electrodes by photolithography.

Next, a molybdenum oxide-containing layer having a thickness of 100 nm was formed by co-evaporation of molybdenum dioxide and molybdenum trioxide as a hole injection layer or a hole transport layer in a vacuum. At this time, the ratio of molybdenum dioxide to molybdenum trioxide was 5%.

Next, using a coating solution in which the weight concentration of the PPV derivative, which is an organic light-emitting material, is 1%, and the weight concentrations of xylene and anisole are 84% and 15%, respectively, hole transport is carried out in the same way in the relief printing method. An organic light emitting layer was formed on the layer. At this time, an 130-line / inch anilox roll and a water development type photosensitive resin plate were used to form an organic light emitting layer having a thickness of 80 nm after drying.

Next, Ba, which is an electron injection material, was formed by vacuum deposition in vacuum using a mask to form an electron injection layer having a line pattern thickness of 5 nm.

Finally, Al, which is a cathode material, was used, and an electrode having a line pattern thickness of 150 nm was formed by a vacuum deposition method in vacuum so as to be orthogonal to the anode formed of ITO. As the line pattern, 192 lines were formed with a line width of 136 μm and a space of 30 μm.
The glass cap and an adhesive were used for hermetically sealing to obtain a passive matrix type organic EL element display device.

As a result of evaluating the light emission characteristics of the display device of the passive matrix type organic EL element obtained in this embodiment, only selected pixels can be lit without short-circuiting between electrodes, and uniform light emission without unevenness is achieved. At the same time, it was possible to obtain good display characteristics of high luminous efficiency, high luminous luminance, and long life with a luminance of 2600 cd / m ^{2 at} 6 V and a luminance half time of 170 hours at an initial luminance of 1800 cd / m ² .

Further, as a result of an accelerated test in a constant temperature and high humidity environment at a temperature of 60 ° C. and a humidity of 90%, no dark spot was observed on the light emitting surface until 3000 hours.

After the molybdenum oxide-containing layer was formed, the transmittance was measured in the visible light region with a wavelength of 380 nm to 800 nm using the portion where only the molybdenum oxide containing layer was formed on the glass substrate. It was 80% or more in the area.

(Example 2)
The structure of the molybdenum oxide-containing layer of Example 1 was made of a layer containing molybdenum trioxide and a molybdenum dioxide layer, and a display device for a passive matrix type organic EL element was produced. The layer containing molybdenum trioxide is formed by depositing molybdenum trioxide to 100 nm in a vacuum by a vacuum deposition method, and then laminating molybdenum dioxide as a molybdenum dioxide layer by a similar method to a thickness of 2 nm. A display device was created.

As a result of evaluating the light emission characteristics of the obtained display device, only selected pixels can be lit without short-circuiting between electrodes, and uniform light emission without unevenness is achieved, and at the same time, the luminance is 6V and 2600 cd / m ² . In addition, a luminance half-life time of 180 hours at an initial luminance of 1800 cd / m ² was 180 hours, and good display characteristics with high luminous efficiency, high luminous luminance, and long life were obtained.

Further, as a result of an accelerated test in a constant temperature and high humidity environment at a temperature of 60 ° C. and a humidity of 90%, no dark spot was observed on the light emitting surface until 3000 hours.

After the molybdenum oxide-containing layer was formed, the transmittance was measured using a portion where only the molybdenum oxide-containing layer was formed on the glass substrate. As a result, the transmittance was 80% or more in the visible light region from 380 nm to 800 nm.

(Example 3)
The molybdenum oxide-containing layer of Example 2 was configured to sandwich a molybdenum dioxide layer of 2 nm between a layer of molybdenum trioxide containing 100 nm, and a display device of a passive matrix type organic EL element was produced.

As a result of evaluating the light emission characteristics of the obtained display device, only selected pixels can be lit without short-circuiting between electrodes, and uniform light emission without unevenness is achieved, and at the same time, the luminance is 2500 cd / m ^{2 at} 6 V, The luminance half-life at an initial luminance of 1800 cd / m ² was 230 hours, and good display characteristics of high luminous efficiency, high luminous luminance, and long life were obtained.

Further, as a result of an accelerated test in a constant temperature and high humidity environment at a temperature of 60 ° C. and a humidity of 90%, no dark spot was observed on the light emitting surface until 4000 hours.

After the molybdenum oxide-containing layer was formed, the transmittance was measured using the portion where only the molybdenum oxide-containing layer was formed on the glass substrate, and it was 77% or more in the visible light region from 380 nm to 800 nm. .

Example 4
The film thickness of the molybdenum dioxide layer of Example 2 was 50 nm, and a passive matrix type organic EL element display device was produced.

As a result of evaluating the light emission characteristics of the obtained display device, only selected pixels can be lit without short-circuiting between electrodes, uniform light emission without unevenness is performed, and at the same time, the luminance is 6V and 1800 cd / m2, With an initial luminance of 1800 cd / m ^2, the luminance half time was 180 hours, and good display characteristics with high luminous efficiency, high luminous luminance, and long life were obtained.

Further, as a result of an accelerated test in a constant temperature and high humidity environment at a temperature of 60 ° C. and a humidity of 90%, no dark spot was observed on the light emitting surface until 3500 hours.

After the molybdenum oxide-containing layer was formed, the transmittance was measured using the portion where only the molybdenum oxide-containing layer was formed on the glass substrate. The transmittance was 60% or more in the visible light region of 380 nm to 800 nm. .

(Example 5)
The film thickness of the molybdenum dioxide layer sandwiching the layer containing molybdenum trioxide of Example 3 was 50 nm, and a passive matrix type organic EL element display device was produced.

As a result of evaluating the light emission characteristics of the obtained display device, only selected pixels can be lit without short-circuiting between electrodes, and uniform light emission without unevenness is achieved. At the same time, the luminance is 6V and 1600 cd / m ² . The luminance half-life at an initial luminance of 1800 cd / m ² was 200 hours, and good display characteristics of high luminous efficiency, high luminous luminance, and long life were obtained.

Further, as a result of an accelerated test in a constant temperature and high humidity environment at a temperature of 60 ° C. and a humidity of 90%, no dark spots were observed on the light emitting surface until 4500 hours.

After the molybdenum oxide-containing layer was formed, the transmittance was measured using the portion where only the molybdenum oxide-containing layer was formed on the glass substrate. The transmittance was 55% or more in the visible light region from 380 nm to 800 nm. .

(Example 6)
The film thickness of the molybdenum dioxide layer of Example 2 was 10 nm, and a passive matrix type organic EL element display device was produced.

As a result of evaluating the light emission characteristics of the obtained display device, only selected pixels can be lit without short-circuiting between electrodes, and uniform light emission without unevenness is performed, and at the same time, the luminance is 6400 and 2400 cd / m ² , The luminance half-life at an initial luminance of 1800 cd / m ² was 230 hours, and good display characteristics of high luminous efficiency, high luminous luminance, and long life were obtained.

Further, as a result of an accelerated test in a constant temperature and high humidity environment at a temperature of 60 ° C. and a humidity of 90%, no dark spot was observed on the light emitting surface until 3800 hours.

After the molybdenum oxide-containing layer was formed, the transmittance was measured using the portion where only the molybdenum oxide-containing layer was formed on the glass substrate, and it was 75% or more in the visible light region from 380 nm to 800 nm. .

(Example 7)
The film thickness of the molybdenum dioxide layer sandwiching the layer containing molybdenum trioxide of Example 3 was 10 nm, and a passive matrix type organic EL element display device was produced.

As a result of evaluating the light emission characteristics of the obtained display device, only the selected pixel can be lit without short-circuiting between electrodes, and uniform light emission without unevenness is performed, and at the same time, the luminance is 6200 V and 2200 cd / m ² , The luminance half-life at an initial luminance of 1800 cd / m ² was 280 hours, and good display characteristics of high luminous efficiency, high luminous luminance, and long life were obtained.

Further, as a result of an accelerated test in a constant temperature and high humidity environment at a temperature of 60 ° C. and a humidity of 90%, no dark spots were observed on the light emitting surface until 4500 hours.

After the molybdenum oxide-containing layer was formed, the transmittance was measured using the portion where only the molybdenum oxide-containing layer was formed on the glass substrate, and it was 77% or more in the visible light region from 380 nm to 800 nm. .

(Example 8)
The molybdenum oxide-containing layer of Example 1 was used as a 40 nm-thick molybdenum oxide-containing layer obtained by co-evaporation of titanium oxide and molybdenum trioxide in vacuum, and a passive matrix type organic EL element display device was produced.

As a result of evaluating the light emission characteristics of the display device of the passive matrix type organic EL element obtained in this embodiment, only selected pixels can be lit without short-circuiting between electrodes, and uniform light emission without unevenness is achieved. At the same time, good display characteristics of high luminous efficiency, high luminous luminance, and long life with a luminance of 2600 cd / m ^{2 at} 6 V and a luminance half time of 300 hours at an initial luminance of 1800 cd / m ² were obtained.

In addition, as a result of an acceleration test in a constant temperature and high humidity environment at a temperature of 60 ° C. and a humidity of 90%, light emission was confirmed up to the upper limit of 5500 hours, but no dark spots were observed on the light emitting surface.

After the molybdenum oxide-containing layer was formed, the transmittance was measured in the visible light region with a wavelength of 380 nm to 800 nm using the portion where only the molybdenum oxide containing layer was formed on the glass substrate. It was 80% or more in the area.

Example 9
The molybdenum oxide-containing layer of Example 1 was used as a 20 nm-thick molybdenum oxide-containing layer in which nickel oxide and molybdenum trioxide were co-deposited in vacuum, and a passive matrix type organic EL element display device was produced.

As a result of evaluating the light emission characteristics of the display device of the passive matrix type organic EL element obtained in this embodiment, only selected pixels can be lit without short-circuiting between electrodes, and uniform light emission without unevenness is achieved. At the same time, good display characteristics of high luminous efficiency, high luminous luminance, and long life with a luminance of 2600 cd / m ^{2 at} 6 V and a luminance half time of 350 hours at an initial luminance of 1800 cd / m ² were obtained.

Further, as a result of an accelerated test in a constant temperature and high humidity environment at a temperature of 60 ° C. and a humidity of 90%, light emission was confirmed up to the upper limit of 5500 hours, but no dark spots were observed on the light emitting surface.

After the molybdenum oxide-containing layer was formed, the transmittance was measured in the visible light region with a wavelength of 380 nm to 800 nm using the portion where only the molybdenum oxide containing layer was formed on the glass substrate. It was 75% or more in the area.

(Comparative Example 1)
The molybdenum oxide-containing layer of Example 1 was not provided, and only molybdenum trioxide was vacuum-deposited as a hole transport layer, to produce a passive matrix type organic EL element display device.

The obtained display device was able to light only selected pixels without short-circuiting between electrodes, but uneven light emission was partially recognized. The luminance was 1500 cd / m ^{2 at} 6 V, and the luminance half time at an initial luminance of 1800 cd / m ² was 150 hours.

Further, as a result of an accelerated test in a constant temperature and high humidity environment at a temperature of 60 ° C. and a humidity of 90%, a dark spot was found on the light emitting surface in 1500 hours, and compared with Example 1 in which a molybdenum oxide-containing layer was provided, lower luminous efficiency The display characteristics were low emission luminance, short life, and low moisture resistance.

After the molybdenum trioxide layer was formed, transmittance measurement was performed using a portion where only the layer containing molybdenum trioxide was formed on the glass substrate, and in the visible light region from 380 nm to 800 nm, the transmittance was 80% or more. there were.

101, 301: substrate 102, 302: first electrode 103, 303: light emitting medium layer 103a, 303a: hole injection layer 103b, 303b: electron blocking layer 103c, 303c: organic light emitting layer 103d, 303d: electron injection layer 104, 304: Molybdenum oxide-containing layers 104a, 104a ′, 304a, 304a ′: Molybdenum trioxide-containing layers 104b, 104b ′, 104c, 104c ′: Layers containing other inorganic compounds 105, 305: Second electrode 306: Insulating layer 201: Printed substrate 202: Ink tank
203: Ink chamber 204: Anilox roll 204a: Coating layer 205: Plate 206: Plate cylinder 207: Flat table

Claims (21)

  A substrate, a first electrode provided on the substrate, a light-emitting medium layer including at least an organic light-emitting layer and a molybdenum oxide-containing layer provided on the first electrode, and the first electrode sandwiching the light-emitting medium layer An organic electroluminescence device comprising an electrode and a second electrode facing the electrode, wherein the molybdenum oxide-containing layer contains at least molybdenum trioxide and another inorganic compound.   2. The organic electroluminescence device according to claim 1, wherein the molybdenum oxide-containing layer includes a layer including at least molybdenum trioxide and a layer including another inorganic compound.   The other inorganic compounds are molybdenum dioxide, indium oxide, titanium oxide, iridium oxide, tantalum oxide, nickel oxide, tungsten oxide, vanadium oxide, tin oxide, lead oxide, niobium oxide, aluminum oxide, copper oxide, manganese oxide, praseodymium oxide. , Chromium oxide, bismuth oxide, calcium oxide, barium oxide, cesium oxide, lithium fluoride, nalium fluoride, zinc selenide, zinc telluride, gallium nitride, gallium nitride indium, magnesium silver, aluminum lithium, copper lithium The organic electroluminescence device according to claim 1, wherein the organic electroluminescence device is a galvanic oxide.   The organic electroluminescence device according to claim 2, wherein the layer containing molybdenum trioxide is a molybdenum trioxide layer.   5. The organic electroluminescence element according to claim 2, wherein a film thickness of the layer containing the other inorganic compound is 5 nm or more and 30 nm or less.   6. The organic electroluminescence according to claim 1, wherein the molybdenum oxide-containing layer is any one of a hole injection layer, a hole transport layer, and a hole injection transport layer. element. A substrate, a first electrode provided on the substrate, a light-emitting medium layer including at least an organic light-emitting layer and a molybdenum oxide-containing layer provided on the first electrode, and the first electrode sandwiching the light-emitting medium layer A method for producing an organic electroluminescence device having a second electrode facing an electrode,
The method for producing an organic electroluminescence element, wherein the step of forming the molybdenum oxide-containing layer includes a step of simultaneously forming a film of at least molybdenum trioxide and another inorganic compound. A substrate, a first electrode provided on the substrate, a light-emitting medium layer including at least an organic light-emitting layer and a molybdenum oxide-containing layer provided on the first electrode, and the first electrode sandwiching the light-emitting medium layer A method for producing an organic electroluminescence device having a second electrode facing an electrode,
The step of forming the molybdenum oxide-containing layer includes a step of forming a film of a first material containing at least molybdenum trioxide and a second material made of another inorganic compound in succession. Manufacturing method of electroluminescent element.   The other inorganic compounds are molybdenum dioxide, indium oxide, titanium oxide, iridium oxide, tantalum oxide, nickel oxide, tungsten oxide, vanadium oxide, tin oxide, lead oxide, niobium oxide, aluminum oxide, copper oxide, manganese oxide, praseodymium oxide. , Chromium oxide, bismuth oxide, calcium oxide, barium oxide, cesium oxide, lithium fluoride, nalium fluoride, zinc selenide, zinc telluride, gallium nitride, gallium nitride indium, magnesium silver, aluminum lithium, copper lithium The method for producing an organic electroluminescent element according to claim 7, wherein the organic electroluminescent element is produced.   The method of manufacturing an organic electroluminescence element according to claim 8, wherein the first material is molybdenum trioxide.   11. The organic electro according to claim 8, wherein a film thickness of the inorganic compound layer formed in the step of forming the second material made of the inorganic compound is 5 nm or more and 30 nm or less. Manufacturing method of luminescence element. A substrate, a first electrode provided on the substrate, a light-emitting medium layer including at least an organic light-emitting layer and a molybdenum oxide-containing layer provided on the first electrode, and the first electrode sandwiching the light-emitting medium layer A method for producing an organic electroluminescence device having a second electrode facing an electrode,
The method of manufacturing an organic electroluminescence element, wherein the step of forming the molybdenum oxide-containing layer includes a step of etching the formed film surface after the step of forming the molybdenum trioxide film.   The method for producing an organic electroluminescent element according to claim 12, wherein the film thickness of the molybdenum dioxide layer formed in the step of etching the film surface is 5 nm or more and 20 nm or less.   14. The method of manufacturing an organic electroluminescence element according to claim 7, wherein the film forming step is a step of forming a film by any one of an evaporation method, a sputtering method, and a CVD method. .   The organic electroluminescence according to any one of claims 7 to 14, wherein the molybdenum oxide-containing layer is any one of a hole injection layer, a hole transport layer, and a hole injection transport layer. Device manufacturing method.   16. The method of manufacturing an organic electroluminescent element according to claim 7, wherein the step of forming at least one of the light emitting medium layer adjacent to the molybdenum oxide-containing layer is a step of forming in the atmosphere. Method.   The organic electroluminescence device according to any one of claims 7 to 16, wherein the step of forming at least one of the light-emitting medium layer adjacent to the molybdenum oxide-containing layer is a step of forming by a wet method. Manufacturing method.   In the step of forming the light emitting medium layer by a wet method, the solvent of the coating liquid for the light emitting medium layer is at least one of water, alcohol, ketone, carboxylic acid, nitrile, ester, and aromatic. The manufacturing method of the organic electroluminescent element of Claim 17 characterized by the above-mentioned.   The method of manufacturing an organic electroluminescence element according to claim 17, wherein the wet method is a printing method.   The method for producing an organic electroluminescence element according to claim 19, wherein the printing method is a relief printing method.   A display device comprising the organic electroluminescence element according to claim 1 as a display element.

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