JPH11111461A - Organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the luminous intensity and keep stable performance even after repeated use by using mixture of a metal oxide or a metal halide and a metal for an electron injection layer. SOLUTION: This organic electroluminescent element comprises at least an organic luminescent layer 3 and an electron injection layer 4 between an anode 1 and a cathode 5 and by using a mixture film of a metal oxide or a metal halide and a metal, the electron injection property is improved. Moreover, by making the film thickness as thin as 0.1-20 nm, the electrolytic intensity is heightened and consequently, the electrons can significantly smoothly flow. As the metal oxide or the metal halide, those having work function of 4.2 eV or lower are preferable and Mg oxide, Mg fluoride, Li fluoride, Li bromide, etc., may be used. As the metal to be mixed, Al, In, Ag, Mg, Au, etc., are preferable. The mixing ratio A:B of (A) metal oxide and/or metal halide to (B) the metal is controlled to be (1:100)-(100:1), preferably (1:20)-(20:1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescence device.

[0002]

2. Description of the Related Art An organic electroluminescence element is an element which emits light in response to an electric signal and is constituted by using an organic compound as a light emitting substance. The organic electroluminescence element basically includes an organic light emitting layer and a pair of counter electrodes sandwiching the organic light emitting layer. In the light emission, electrons are injected from one of the electrodes and holes are injected from the other electrode, so that the luminescent material in the luminescent layer is excited to a higher energy level, and the excited luminescent material is returned to its original base. When returning to the state, the extra energy is emitted as light.

In order to increase the luminous efficiency, in addition to the above-mentioned basic structure, a hole injection layer is further provided on an electrode for injecting holes, and an electron transport layer is provided on an electrode for injecting electrons. Configuration has been taken.

[0004] As an example of an organic electroluminescence device, a device using single crystal anthracene or the like as a light emitting body is described in US Pat. No. 3,539,325. In addition, Japanese Patent Application Laid-Open No. 59-194393 proposes a combination of a hole injection layer and an organic luminescent layer. JP-A-63-295695 proposes a combination of an organic hole injection / transport layer and an organic electron injection / transport layer.

The electroluminescent device having such a laminated structure has a structure in which an organic phosphor, a charge transporting organic substance (charge transporting material) and an electrode are laminated, and holes and electrons injected from each electrode are charged. Light is emitted as they move through the transport material and recombine. As an organic phosphor, 8
-Organic dyes that emit fluorescence such as quinolinol aluminum complex and coumarin compounds are used. As the charge transporting material, for example, N, N'-di (m-tolyl)
Diamino compounds such as N, N'-diphenylbenzidine and 1,1-bis [N, N-di (p-tolyl) aminophenyl] cyclohexane, and 4- (N, N-diphenyl) aminobenzaldehyde-N, N- And diphenylhydrazone compounds. Further, porphyrin compounds such as copper phthalocyanine have been proposed.

Incidentally, the organic electroluminescence element has high light emission characteristics, but is not sufficient in light emission stability and storage stability, and has not been put to practical use. It has been pointed out that the stability of the charge transporting material is one of the problems in the light emission stability and storage stability of the device.
A layer formed of an organic material of an electroluminescent device is very thin, hundreds to hundreds of nanometers, and a voltage applied per unit thickness is very high. In addition, heat is generated by light emission and energization. Therefore, the charge transporting material is required to have electrical, thermal or chemical stability.

In order to reduce the light emission starting voltage of the organic electroluminescence element, those using a material other than aluminum for the cathode in place of aluminum which has been conventionally used are disclosed in JP-A-2-15595 and JP-A-3-37994.
JP, JP-A-4-132191, JP-A-5-1
No. 2,172,172.

Japanese Patent Application Laid-Open No. 4-132189 discloses an electron injection layer using a film in which an electron transport material and a metal are mixed.
And JP-A-7-268317.

However, those using a metal other than aluminum have problems such as difficult film formation conditions and easy oxidation, and the same problem occurs when an electron transport material and a metal are mixed.

At present, an electron injection layer having good characteristics has not been obtained so far.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an organic electroluminescent device having a high emission intensity and exhibiting stable performance even when used repeatedly. An object of the present invention is to provide a luminescence element.

[0012]

According to the present invention, there is provided an organic electroluminescence device provided with at least an anode, a light emitting layer, an electron injection layer and a cathode, wherein the electron injection layer is a mixture of a metal oxide or a metal halide and a metal. The present invention relates to an organic electroluminescence device, which is a film.

The organic electroluminescence device of the present invention comprises at least a light emitting layer and an electron injection layer between electrodes. The present invention is fundamentally characterized in that the electron injection layer of the organic electroluminescence element is a metal oxide or a mixed film of a metal halide and a metal. Hereinafter, the present invention will be described with reference to FIG. FIG.
Shows an example of the configuration of an organic electroluminescent element to which the present invention can be applied. In the figure, (1) is an anode,
On top of that, a hole injection / transport layer (2) and an organic light emitting layer (3),
An electron injection layer (4) and a cathode (5) are sequentially laminated.

As the conductive material used as the anode (1) of the organic electroluminescence device, those having a work function of more than 4 eV are preferable, and carbon, aluminum, vanadium, iron, cobalt, nickel, copper, zinc,
Tungsten, silver, tin, gold, and alloys thereof, and conductive metal compounds such as tin oxide, indium oxide, antimony oxide, zinc oxide, and zirconium oxide are used.

Examples of the metal forming the cathode (5) include aluminum, silver, and those having a work function smaller than 4 eV, such as magnesium, calcium, titanium,
Yttrium, lithium, gadolinium, ytterbium, ruthenium, manganese and their alloys are used.

In the organic electroluminescence element, at least the anode (1) or the cathode (5) needs to be a transparent electrode so that light emission can be seen. On this occasion,
If a transparent electrode is used for the cathode, the transparency is likely to be impaired.

When forming a transparent electrode, on a transparent substrate,
Using a conductive material as described above, a device such as vapor deposition, sputtering, or a method such as a sol-gel method or a method of dispersing and applying in a resin or the like is used to secure desired translucency and conductivity. I just need.

The transparent substrate is not particularly limited as long as it has an appropriate strength, is not adversely affected by heat due to vapor deposition or the like when an organic electroluminescence device is manufactured, and is transparent. It is also possible to use a glass substrate, a transparent resin such as polyethylene, polypropylene, polyethersulfone, polyetheretherketone, and the like. As a transparent electrode formed on a glass substrate, commercially available products such as ITO and NESA are known, but these may be used.

FIG. 1 shows a structure in which a hole injection / transport layer (2) is formed on the above-mentioned anode (1). The hole injection transport layer (2) may be formed by vapor deposition of a compound, or may be formed by dip coating or spin coating a solution in which the compound is dissolved or a solution in which a suitable resin is dissolved.

When the hole injecting and transporting layer (2) is formed by a vapor deposition method, its thickness is usually 1 to 200 nm, preferably 5 to 200 nm.
To 100 nm, and 5 to 5 when formed by a coating method.
It may be formed to a thickness of about 00 nm. As the film thickness is larger, the applied voltage for emitting light needs to be higher, and the luminous efficiency is poor, and the organic electroluminescent element is likely to be deteriorated. When the film thickness is small, the luminous efficiency is improved, but the breakdown is easy and the life of the organic electroluminescent element is shortened.

As the hole injecting and transporting material used in the hole injecting and transporting layer, known materials can be used, for example, N, N '.
-Diphenyl-N, N'-bis (3-methylphenyl)
-1,1'-diphenyl-4,4'-diamine, N, N '
-Diphenyl-N, N'-bis (4-methylphenyl)
-1,1'-diphenyl-4,4'-diamine, N, N '
-Diphenyl-N, N'-bis (1-naphthyl) -1,
1'-diphenyl-4,4'-diamine, N, N'-diphenyl-N, N'-bis (2-naphthyl) -1,1'-diphenyl-4,4'-diamine, N, N'- Tetra (4-
Methylphenyl) -1,1′-diphenyl-4,4′-diamine, N, N′-tetra (4-methylphenyl)-
1,1′-bis (3-methylphenyl) -4,4′-diamine, N, N′-diphenyl-N, N′-bis (3-methylphenyl) -1,1′-bis (3-methyl Phenyl)
-4,4′-diamine, N, N′-bis (N-carbazolyl) -1,1′-diphenyl-4,4′-diamine,
4 ', 4 "-tris (N-carbazolyl) triphenylamine, N, N', N" -triphenyl-N, N ', N "-tris (3-methylphenyl) -1,3,5-tri (4-
Aminophenyl) benzene, 4,4 ', 4 "-tris [N, N', N" -triphenyl-N, N ', N "-tris (3-methylphenyl)] triphenylamine and the like. These may be used in combination of two or more.

An organic light emitting layer (3) is formed on the hole injection / transport layer (2). As the organic light emitting material used for the organic light emitting layer (3), known organic light emitting materials can be used, for example, epidolidine, 2,5-bis [5,7-di-t-pentyl-2-benzoxazolyl] thiophene. , 2, 2 '
-(1,4-phenylenedivinylene) bisbenzothiazole, 2,2 ′-(4,4′-biphenylene) bisbenzothiazole, 5-methyl-2- {2- [4- (5-methyl-2- Benzoxazolyl) phenyl] vinyl} benzoxazole, 2,5-bis (5-methyl-2-benzooxazolyl) thiophene, anthracene, naphthalene, phenanthrene, pyrene, chrysene, perylene, perinone, 1,4-diphenyl Butadiene, tetraphenylbutadiene, coumarin, acridine, stilbene, 2
-(4-biphenyl) -6-phenylbenzoxazole, aluminum trisoxin, magnesium bisoxin, bis (benzo-8-quinolinol) zinc, bis (2-methyl-8-quinolinolalto) aluminum oxide, indium trisoxin, aluminum tris (5-methyloxin), lithium oxine, gallium trisoxin, calcium bis (5-chlorooxin), polyzinc-bis (8-hydroxy-5-quinolinolyl) methane, dilithium epindridione, zinc bisoxin, Examples thereof include 2-phthaloperinone and 1,2-naphthaloperinone.

In addition, general fluorescent dyes such as fluorescent coumarin dyes, fluorescent perylene dyes, fluorescent pyran dyes, fluorescent thiopyran dyes, fluorescent polymethine dyes, fluorescent methyanine dyes, fluorescent imidazole dyes, etc. Can be used. Among them, particularly preferred are chelated oxinoid compounds.

The organic light-emitting layer may have a single-layer structure of the above-described light-emitting substance, or may have a multi-layer structure in order to adjust characteristics such as light emission color and light emission intensity. Further, two or more kinds of light emitting substances may be mixed, or the light emitting layer may be doped with another light emitting substance.

When formed by a vapor deposition method, the thickness is usually 1 to 200 nm, preferably 1 to 100 nm. When formed by a coating method, the thickness may be about 5 to 500 nm. As the film thickness is larger, the applied voltage for emitting light needs to be higher, and the luminous efficiency is poor, and the organic electroluminescent element is likely to be deteriorated. When the film thickness is small, the luminous efficiency is improved, but the breakdown is easy and the life of the organic electroluminescent element is shortened.

Next, a mixed film of metal oxide or metal halide and metal is formed as an electron injection layer (4) on the organic light emitting layer (3). The metal oxide or metal halide mixed in the electron injection layer preferably has a work function smaller than 4.2 eV, and is preferably magnesium oxide, magnesium fluoride, calcium fluoride, yttrium oxide, yttrium fluoride, lithium fluoride. And lithium bromide. In particular, magnesium fluoride, calcium fluoride, lithium fluoride, yttrium fluoride, and magnesium oxide are preferable from the viewpoint of light emission characteristics and film forming properties. Aluminum, indium, silver, magnesium, gold, or the like is used as the metal mixed in the electron injection layer. Among these, aluminum, indium, silver, and gold having a work function higher than 4.2 eV are preferable.

The mixing ratio between the metal oxide or metal halide and the metal (metal oxide and / or metal halide: metal) is 1: 100 to 100: 1, preferably 1:20 to 20: 1.

The electron injection layer (4) is formed by a vacuum evaporation method, and has a thickness of 0.1 to 20 nm. As the film thickness is larger, the applied voltage for emitting light needs to be higher, and the luminous efficiency is poor, and the organic electroluminescent element is likely to be deteriorated. In addition, when the film thickness is small, it is difficult to form a uniform film, and defects tend to occur. As a result, the luminous efficiency is deteriorated and the life of the organic electroluminescent element is shortened.

The mixed film of metal oxide or metal halide and metal can be formed by a conventional resistance heating method, sputtering method, EB
The film can be formed by various known evaporation methods such as an evaporation method, an ion plating method, and an ionization evaporation method.

FIGS. 2 to 4 show an organic electroluminescent device having another structure. In FIG. 2, reference numeral (1) denotes an anode, on which a hole injection / transport layer (2), an organic light emitting layer (3), an electron transport layer (6), an electron injection layer (4), and a cathode (5). Are sequentially laminated, and the electron injection layer is a mixed film of a metal and a metal oxide or a metal halide.

In FIG. 3, (1) is an anode, on which a hole injection layer (7) and a hole transport layer (8), an organic light emitting layer (3), an electron transport layer (6), an electron It has a configuration in which an injection layer (4) and a cathode (5) are sequentially laminated, and the electron injection layer is a mixed film of a metal and a metal oxide or a metal halide.

In FIG. 4, (1) is an anode, on which a hole injection layer (7), a hole transport layer (8) and an organic light emitting layer (3), an electron injection layer (4) and a cathode are provided. (5) A configuration in which a sealing layer (9) is sequentially laminated is adopted, and the electron injection layer is a mixed film of a metal and a metal oxide or a metal halide.

When the electron transport layer (6) is formed between the organic light emitting layer (3) and the electron injection layer (4) as shown in FIG. 2 or FIG. It is formed to have a thickness of about 1 to 100 nm. As the electron transporting material used for the electron transporting layer, known materials can be used, and examples thereof include oxadiazole derivatives, thiadiazole derivatives, chelated oxinoid compounds, benzothiazole complexes, and benzoxazole complexes. The electron transporting layer can be formed by a conventionally known method such as a vapor deposition method and a coating method, similarly to the light emitting layer.

When the above-mentioned organic light emitting substance has an electron transporting function, the organic light emitting substance may be used as an electron transporting material of an electron transporting layer. In that case, the same substance can be used for the light emitting layer, and the light emitting layer can be a doped light emitting layer. For example, the electron transporting layer can be formed of aluminum trisoxine, and in this case, the light emitting layer is preferably formed of a layer obtained by doping aluminum trisoxin with a light emitting body.

In the organic electroluminescence device shown in FIGS. 3 and 4, the hole injection / transport layer of FIG. 1 is functionally separated into two layers, a hole injection layer (7) and a hole transport layer (8). It has a configuration. The hole injection layer (7) is formed to a thickness of about 1 to 30 nm using a known material, for example, a phthalocyanine compound, a conductive polymer compound, an arylamine compound, or the like, by means of vapor deposition or the like. The hole transport layer (8)
Is formed using a known material, for example, a benzidine compound, an arylamine compound, a styryl compound, or the like, to a thickness of about 10 to 200 nm by means such as vapor deposition.

When the sealing layer (9) is formed as shown in FIG. 4, a thin film is formed by a vacuum evaporation method using a compound such as silicon oxide, zinc oxide, magnesium fluoride, and magnesium oxide. The thickness is about 5 to 1000 nm.

A pair of transparent electrodes, a cathode (5) and an anode (1), is connected to a suitable lead wire (10) such as a nichrome wire, a gold wire, a copper wire, a platinum wire, etc. The sense element emits light by applying an appropriate voltage (Vs) to both electrodes.

According to the present invention, an electron injection property is improved by using a mixed film of a metal and a metal oxide or a metal halide for the electron injection layer, and the film thickness is reduced to 0.1 to 20 nm. By increasing the electric field strength, the flow of electrons becomes extremely smooth, and the light emission starting voltage required for causing the organic electroluminescence device of the present invention to emit light may be low, and therefore, light emission for a long time is stable. It is considered possible. The thickness of each of the above layers such as the electron injection layer can be measured using a quartz oscillation type thickness gauge.

The organic electroluminescent device of the present invention is applicable to various display devices, display devices, and the like.

Hereinafter, the present invention will be described by way of examples.
The organic electroluminescent device of the present invention achieves an improvement in luminous efficiency, luminous brightness and a long life. The following examples describe the luminescent substance, luminescent auxiliary material, charge transport material, The invention is not intended to be limited to agents, resins, electrode materials, and the like, and element manufacturing methods.

Example 1 N, N'-diphenyl-N, N'-bis (3-N-N-N-diphenyl-N, N'-bis
A thin film having a thickness of 60 nm was formed by vapor deposition of (methylphenyl) -1,1′-diphenyl-4,4′-diamine.
Aluminum trisoxine was deposited thereon as an organic light emitting layer to form a thin film having a thickness of 60 nm.

A thin film of lithium fluoride and aluminum was formed thereon as an electron injection layer by a co-evaporation method using resistance heating so as to have a volume ratio of 1: 1 and a thickness of 1 nm. Next, a thin film was formed to a thickness of 200 nm by vapor deposition of aluminum as a cathode. Thus, an organic electroluminescence device was manufactured.

EXAMPLE 2 N, N′-diphenyl-N, N′-bis (3-N-N-diphenyl-N, N′-bis
(Methylphenyl) -1,1′-diphenyl-4,4′-diamine was deposited to form a thin film having a thickness of 60 nm. Aluminum trisoxine was deposited thereon as an organic light emitting layer to form a thin film having a thickness of 60 nm.

A thin film of lithium fluoride and aluminum was formed thereon as an electron injection layer by a co-evaporation method using resistance heating at a volume ratio of 1: 2 to a thickness of 3 nm. Next, a thin film was formed to a thickness of 200 nm by vapor deposition of aluminum as a cathode. Thus, an organic electroluminescence device was manufactured.

Example 3 N, N'-diphenyl-N, N'-bis (3-N-N-diphenyl-N, N'-bis
(Methylphenyl) -1,1′-diphenyl-4,4′-diamine was deposited to form a thin film having a thickness of 60 nm. Aluminum trisoxine was deposited thereon as an organic light emitting layer to form a thin film having a thickness of 60 nm.

A thin film of lithium fluoride and indium was formed thereon as an electron injection layer by a co-evaporation method using resistance heating so as to have a thickness of 1 nm at a volume ratio of 1: 5. Next, aluminum was deposited as a cathode to form a thin film to a thickness of 200 nm. Thus, an organic electroluminescence device was manufactured.

Example 4 On the substrate of indium tin oxide coated glass, N, N'-diphenyl-N, N'-bis (3-
(Methylphenyl) -1,1′-diphenyl-4,4′-diamine was deposited to form a thin film having a thickness of 60 nm. Aluminum trisoxine was deposited thereon as an organic light emitting layer to form a thin film having a thickness of 60 nm.

On top of that, magnesium fluoride and aluminum were used as an electron injection layer by co-evaporation using resistance heating.
A thin film was formed to have a thickness of 1 nm at a volume ratio of 1. Next, aluminum was deposited as a cathode to a thickness of 200 nm.
A thin film was formed to have a thickness of. In this way,
An organic electroluminescence device was manufactured.

Comparative Example 1 An organic electroluminescent device was produced in the same manner as in Example 1 except that the electron injection layer was not provided.

Comparative Example 2 In Example 1, a thin film was formed as an electron injection layer by co-evaporation of indium by resistance heating so as to have a thickness of 1 nm to form an electron injection layer. Next, aluminum was deposited as a cathode to form a thin film having a thickness of 200 nm. Thus, an organic electroluminescence device was manufactured.

Comparative Example 3 In Example 3, a thin film was formed as an electron injecting layer so as to have a thickness of 3 nm at a volume ratio of 2: 1 by co-evaporation of aluminum trisoxine and magnesium by resistance heating. Next, a thin film was formed to a thickness of 200 nm by vapor deposition of aluminum as a cathode. Thus, an organic electroluminescence device was manufactured.

Example 5 An N, N'-diphenyl-N, N'-bis (1
-Naphthyl) -1,1'-diphenyl-4,4'-diamine was deposited to form a thin film having a thickness of 55 nm. On top of this, an organic light-emitting layer obtained by doping aluminum trisoxine with 5% by weight of rubrene was co-evaporated to a thickness of 10 n.
A thin film was formed to have a thickness of m.

Next, aluminum trisoxine was deposited as an electron transporting layer to form a thin film having a thickness of 45 nm. Magnesium fluoride and indium were used as an electron injection layer thereon by a co-evaporation method using resistance heating at a ratio of 1: 5.
A thin film was formed so as to have a thickness of 2 nm with a volume ratio of 2 nm.
Finally, indium was deposited as a cathode to form a thin film having a thickness of 200 nm. Thus, an organic electroluminescence device was manufactured.

Comparative Example 4 An organic electroluminescent device was produced in the same manner as in Example 5 except that the electron injection layer was not provided.

Comparative Example 5 In Example 5, a thin film having a thickness of 2 nm was formed as an electron injection layer by evaporation of magnesium fluoride by resistance heating. Next, indium was deposited as a cathode to form a thin film having a thickness of 200 nm. Thus, an organic electroluminescence device was manufactured.

Example 6 An N, N'-diphenyl-N, N'-bis (1
-Naphthyl) -1,1'-diphenyl-4,4'-diamine was deposited to form a thin film having a thickness of 55 nm. On top of this, an organic light-emitting layer obtained by doping aluminum trisoxine with 5% by weight of rubrene was co-evaporated to a thickness of 10 n.
A thin film was formed to have a thickness of m.

Next, aluminum trisoxin was deposited as an electron transporting layer to form a thin film having a thickness of 45 nm. Yttrium fluoride and aluminum are then formed as an electron injection layer by co-evaporation with resistance heating at a ratio of 1: 1.
A thin film was formed so as to have a thickness of 1 nm by volume ratio.
Finally, aluminum was deposited as a cathode to form a thin film having a thickness of 200 nm. Thus, an organic electroluminescence device was manufactured.

Example 7 4,4 ', 4 "-tris [N, N', N" -triphenyl-N, N ', N "was formed as a hole injection layer on a glass substrate coated with indium tin oxide. -Tris (3-methylphenyl)] triphenylamine was deposited to form a thin film having a thickness of 15 nm, and N, N′-diphenyl-N, N was formed as a hole transport layer on the hole injection layer. '-Bis (4-methylphenyl) -1,1'-bis (3-methylphenyl)-
4,4′-Diamine was deposited to form a thin film having a thickness of 45 nm.

An organic light emitting layer was co-evaporated with aluminum trisoxin doped with 5% by weight of rubrene to form a thin film having a thickness of 30 nm. Next, the following oxadiazole compound (A) is used as an electron transport layer:

Embedded image Was deposited to form a thin film having a thickness of 30 nm.

On top of this, magnesium oxide and indium were used as an electron injection layer in a ratio of 1: 3 by co-evaporation using resistance heating.
A thin film was formed so as to have a thickness of 2 nm with a volume ratio of 2 nm.
Finally, aluminum was deposited as a cathode to form a thin film having a thickness of 200 nm. Thus, an organic electroluminescence device was manufactured.

Comparative Example 6 An organic electroluminescent device was produced in the same manner as in Example 7 except that the electron injection layer was not provided.

Evaluation The organic electroluminescent devices obtained in Examples 1 to 7 and Comparative Examples 1 to 6 were applied with a glass electrode as an anode and a voltage (V) at which light emission was started when a DC voltage was gradually applied. ) and luminance (cd / m ² when applying a DC voltage of 5V), to measure the emission luminance when applying a direct current voltage of 10V (cd / m ^2). In addition, 5 mA / cm ²
The reduction rate (%) of the initial output when the device was operated at the current density of 5 hours for 5 hours [output (mW / cm ² ) after 5 hours / initial output (mW / cm ² ) × 100] was determined. Table 1 shows the measurement results.
Are shown together.

[0063]

[Table 1]

As can be seen from Table 1, the organic electroluminescent device of this example started to emit light at a low potential and exhibited good emission luminance. In the organic electroluminescence device of this example, the output was small and a stable light emission with a long life was observed.

[0065]

According to the present invention, it is possible to obtain an organic electroluminescence device having a high light emission intensity, a low light emission starting voltage and excellent durability by including a specific compound in the electron injection layer of the organic electroluminescence device. it can.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of one configuration example of an organic electroluminescence element of the present invention.

FIG. 2 is a schematic cross-sectional view of one configuration example of the organic electroluminescence element of the present invention.

FIG. 3 is a schematic cross-sectional view of one configuration example of the organic electroluminescence element of the present invention.

FIG. 4 is a schematic cross-sectional view of one configuration example of the organic electroluminescence element of the present invention.

[Explanation of symbols]

1: anode, 2: hole injection / transport layer, 3: organic light emitting layer, 4:
Electron injection layer, 5: cathode, 6: electron transport layer, 7: hole injection layer, 8: hole transport layer, 9: sealing film, 10: lead wire

Claims (4)

[Claims] 1. An organic electroluminescence device provided with at least an anode, a light emitting layer, an electron injection layer and a cathode, wherein the electron injection layer is a mixed film of a metal oxide or a metal halide and a metal. Organic electroluminescent element. 2. The electron injection layer having a thickness of 0.1 nm to 20 nm.
2. The organic electroluminescent device according to claim 1, wherein the wavelength is nm. 3. The organic electroluminescent device according to claim 1, wherein the work function of the metal oxide or metal halide mixed in the electron injection layer is 4.2 eV or less. 4. The organic electroluminescent device according to claim 1, wherein the metal mixed in the electron injection layer is aluminum or indium.