JP2002313573A - Organic electroluminescent element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element emitting yellow to red light, capable of maintaining a stable light emission characteristic over a long period. SOLUTION: The organic electroluminescent element has in a light-emitting layer 3 the specific anthracene derivative represented by formula (1). In the formula (1), each of X<1> and X<2> represents a hydrogen atom, an iodine atom, or an NH group, etc., and each of R<1> to R<16> represents a hydrogen atom, a halogen atom, or a phenyl group, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescence (E) having improved light emission characteristics and lifetime characteristics.
L) An element.

[0002]

2. Description of the Related Art With the rapid progress of technological development in the field of information communication in recent years, great expectations have been placed on flat displays instead of CRTs. Among them, organic EL elements have been actively studied because they are excellent in high-speed response, visibility, luminance and the like.

The organic EL device disclosed by Tang et al. Of Kodak Company in 1987 has a two-layer structure of an organic thin film, and a tris (8-quinolinolato) aluminum (hereinafter abbreviated as "Alq") for a light emitting layer. ) And 1
By driving at a low voltage of 0 V or less, a high luminance of 1000 cd / m ² was obtained. This device has a luminous efficiency of 1.5 lm /
W green light-emitting element (Appl. Phys. Le).
tt. , 51, 913 (1987)).

[0004] As a method for improving the luminous efficiency of an organic EL element or changing a luminescent color, a method of doping a luminescent layer with a dye is known. For example, using Alq as a host material for the light emitting layer, a coumarin derivative or 4-dicyanomethylene-2-methyl-6-p having a high fluorescence quantum yield can be used.
-Dimethylaminostyryl-4H-pyran (hereinafter referred to as “DC
M) (which is abbreviated as "M") as a doping dye to improve the luminous efficiency and to change the luminescent color to red.
s. , 65, 3610 (1989)).

A device doped with quinacridone is particularly excellent in improving luminous efficiency, and a combination of Alq and quinacridone (Polymer preprints, Japan 40, 3600 (199)
1)), a combination of bis (10-hydroxybenzo [h] -quinolinate) beryllium and quinacridone (Extended
Abstracts, No3,1073,41st Spring Meeting of the Jap
an Soc. of Appl. Phys (1994)).

However, as the conventionally known dope dyes, there are many dyes that emit blue to yellow. Examples of the dope dye for producing a reddish color include the above-mentioned DCM derivative, Neil Red (Science 267,1332 (1995)), perylene derivative (Appl. Phys. Lett., 64, 187 (1993)), and europium complex (Chem. Lett., 1267 (1991)), but they are not always satisfactory in terms of luminous efficiency and long-term stability. Therefore, development of a doped dye which provides a red fluorescent material having excellent luminous efficiency and excellent life is desired.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide an organic EL device which is excellent in luminous efficiency and emits light stably for a long period of time. Another object of the present invention is to provide an organic EL device which can be applied to multi-color display or full-color display, and particularly emits yellow to red light.

[0008]

The present invention relates to an organic EL device having a layer containing a specific anthracene derivative. An organic electroluminescence device having a layer containing an anthracene derivative represented by the following formula (1) between an anode and a cathode.

[0009]

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(In the formula (1), X ¹ and X ² each independently represent an oxygen atom, a sulfur atom, an NH group or a CH ₂ group, and R ^{1 to} R ¹⁶ each independently represent a hydrogen atom, Represents a halogen atom or a monovalent organic group).

The layer containing the anthracene derivative represented by the above formula (1) is preferably a light emitting layer. In this case, the light emitting layer contains the anthracene derivative represented by the above formula (1) and another organic fluorescent substance. It is preferable that the light-emitting layer include a light-emitting layer.
Further, in the light emitting layer, the anthracene derivative represented by the above formula (1) is added to the anthracene derivative represented by the above formula (1) in an amount of 0.01 to 0.01 with respect to the total amount of the anthracene derivative represented by the above formula (1) and another organic fluorescent substance.
It is preferable to contain 20 mol%.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, by using a specific anthracene derivative, an organic EL device having excellent light emitting efficiency of a light emitting layer and stable light emission over a long period of time can be obtained. Also, a yellow to red organic EL element applicable to multi-color display and full-color display can be obtained.

Anthracene dyes have long been known as high fluorescent quantum yield dyes for organic EL (Phy).
s. Rev. Lett., 14,229, (1965)). However, it has been insufficient to obtain long-wavelength emission of yellow to red emission or to obtain stable emission over a long period of time.
The present inventor has proposed that the conjugation of the anthracene derivative be widened in order to obtain yellow to red light emission, and that two adjacent to the anthracene skeleton be used in order to obtain stable light emission over a long period of time.
It has been found that it is important to suppress the rotation of the heavy bond, and as a result, by using an anthracene derivative represented by the formula (1) (hereinafter referred to as an anthracene derivative (1)), the emission of yellow to red light is increased. It has been found that emission at a wavelength can be obtained and that emission can be obtained stably over a long period of time.

Further, the anthracene derivative (1) has high heat resistance as a substance, and also has the effect of improving the stability of a thin film and the half life of luminance. Further, even in continuous driving or pulse driving, stable characteristics with high luminance can be obtained over a long period of time.

In the formula (1), X ¹ and X ² each independently represent an oxygen atom, a sulfur atom, an NH group or a CH ₂ group. Among them, it is most preferred that X ¹ and X ² are the same atom or group, and then a combination in which one is an oxygen atom or a sulfur atom and the other is an atom or a group different therefrom.

R ^{1 to} R ¹⁶ each independently represent a hydrogen atom, a halogen atom or a monovalent organic group. As the halogen atom, a fluorine atom and a chlorine atom are preferable. Examples of the monovalent organic group include an alkyl group having 1 to 12 carbon atoms and 1 to 12 carbon atoms.
12 alkenyl groups, an alkoxy group having 1 to 12 carbon atoms,
An alkylamino group having 1 to 12 carbon atoms, an aryl group having 1 to 18 carbon atoms, an aralkyl group having 1 to 18 carbon atoms, and 1 carbon atom
To 18 aryloxy groups, 1 to 18 carbon atoms, arylamino groups, 1 to 18 carbon acyl groups, or 1 to 1 carbon atoms
Preferred are 18 aromatic heterocyclic groups. Some of the hydrogen atoms bonded to the carbon atoms of these monovalent organic groups may be substituted with monovalent substituents other than organic groups such as halogen atoms, and between the carbon-carbon bonds of these monovalent organic groups. May have a divalent atom such as an etheric oxygen atom inserted.
The alkyl group, alkenyl group and alkoxy group preferably have 6 or less carbon atoms, particularly preferably 4 or less. Examples of the alkylamino group include a monoalkylamino group and a dialkylamino group, and the alkyl group preferably has 1 to 4 carbon atoms.

As the aryl group and the aryl group in the aralkyl group, the aryloxy group and the arylamino group, a phenyl group which may have a substituent is preferable. As the substituent, an alkyl group having 1 to 4 carbon atoms and a halogen atom are preferable. The number of carbon atoms in the alkyl portion of the aralkyl group is preferably 4 or less, and the arylamino group may be either a monoarylamino group or a diarylamino group. As the acyl group, an acyl group having 8 or less carbon atoms is preferable. Examples of the aromatic heterocyclic group include a pyridyl group, a thiophenyl group, and a furyl group, and the above-mentioned substituent may be bonded to the ring.

The organic EL device of the present invention basically comprises an anode, a cathode, and a light emitting layer sandwiched between them. As described below, a hole transport layer, an electron transport layer, an interface layer, and other intermediate layers may be provided between the anode and the cathode.
The layer containing the anthracene derivative (1) in the present invention is usually a light emitting layer, but is not limited to this, and may be included in another layer present between the anode and the cathode. The light emitting layer containing the anthracene derivative (1) may contain another organic fluorescent substance in addition to the anthracene derivative (1). When the anthracene derivative (1) is contained in a layer other than the light-emitting layer, the layer other than the light-emitting layer is preferably a layer containing an organic substance, such as a hole transport layer and an interface layer.

As the organic EL device of the present invention, an organic EL device having a light emitting layer containing an anthracene derivative (1) and another organic fluorescent substance between an anode and a cathode is preferable. In this case, the concentration of the anthracene derivative (1) with respect to the sum of the anthracene derivative (1) and the other organic fluorescent substance in the light emitting layer is preferably 0.01 to 20 mol%. When the content is 0.01 mol% or more, the energy transfer efficiency from other organic fluorescent substances can be increased, and when the content is 20 mol% or less, a decrease in emission luminance due to concentration quenching can be suppressed. When the anthracene derivative (1) is included in a layer other than the light emitting layer, the concentration of the anthracene derivative (1) with respect to the total amount of the layer and the organic substance is preferably 0.01 to 20 mol%.

As the organic fluorescent substance other than the anthracene derivative (1), a compound having high fluorescence quantum yield, high electron injection efficiency from the cathode and high electron mobility is preferable.
Known organic fluorescent substances can be used. In the present invention, an 8-oxyquinoline-based complex represented by the following formula (2) is particularly preferable as another organic fluorescent substance.

[0021]

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In the above formula (2), A ^{1 to} A ⁶ each independently represent a hydrogen atom, a halogen atom, a nitro group, a hydroxyl group, a cyano group or a monovalent organic group, M represents a metal atom,
n is an integer of 1 to 3; L is an alkoxy group having 1 to 12 carbon atoms or an aryloxy group having 1 to 18 carbon atoms;
Represents an integer of ２2. As the halogen atom, a fluorine atom and a chlorine atom are preferable.

As the monovalent organic group, the monovalent organic groups described in the description of the above formula (1) are preferable.
2, an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkylamino group having 1 to 12 carbon atoms, an aryl group having 1 to 18 carbon atoms, and 1 to 1 carbon atoms
8 aralkyl group, 1 to 18 carbon atom aryloxy group, 1 to 18 carbon atom arylamino group, 1 to 1 carbon atom
8 acyl groups are preferred.

As the monovalent organic group from the alkyl group to the acyl group represented by A ^{1 to} A ⁶ , a group in the same range as the alkyl group to the acyl group in the preferred range in the above formula (1) is preferable. The alkoxy group and the aryloxy group as L are also preferably the alkoxy group and the aryloxy group in this preferred range.

As the metal atom M, lithium, silver, beryllium, magnesium, calcium, strontium,
Examples include zinc, cadmium, aluminum, gallium, indium, thallium, yttrium, scandium, lanthanum, lead, zirconium, manganese, and lutetium. Among these, beryllium, magnesium, aluminum, zinc, and scandium having high fluorescence quantum yield are preferable.

In addition to the 8-oxyquinoline-based complex represented by the formula (2), tetraphenylbutadiene, styryl-based dyes, oxadiazole-based dyes, and the like can be used as the organic fluorescent substance in the light-emitting layer. In addition, a high molecular compound such as a polyphenylenevinylene derivative or a polyfluorene derivative can also be used. However, when the organic fluorescent substance is a polymer compound, the preferable molar concentration of the anthracene derivative (1) with respect to the total amount of the anthracene derivative (1) is calculated assuming that each monomer unit of the polymer compound is 1 mole.

The light emitting layer in the organic EL device of the present invention may further contain other compounds in addition to the organic fluorescent substance (anthracene derivative (1) and other organic fluorescent substances).
As the other compound, a dye is preferable, and a doped dye other than the anthracene derivative (1) is particularly preferable.

As the doped dye other than the anthracene derivative (1), a known fluorescent organic dye can be used. For example, laser dyes such as stilbene dyes, oxazole dyes, cyanine dyes, xanthene dyes, oxazine dyes, coumarin dyes, and acridine dyes, and anthracene derivatives, naphthacene derivatives, pentacene derivatives, pyrene derivatives, and perylene derivatives. , Aromatic hydrocarbon-based substances, DCM derivatives, europium complexes and the like. If such a doped dye is used, its concentration in the light emitting layer should be 0,1.
It is preferably from 01 to 20 mol%.

Hereinafter, the organic EL device of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a basic configuration of an organic EL device of the present invention, and FIG. 2 is a side view of an application example thereof. The organic EL device shown in FIG. 1 includes a substrate 1, an anode 2, a light emitting layer 3, and a cathode 4. The organic EL device shown in FIG. 2 has a hole transport layer 5 and an interface layer 6 between the anode 2 and the light emitting layer 3.
And an electron transport layer 7 between the cathode 4 and the light emitting layer 3.
And an interface layer 8.

The substrate 1 is a support for the organic EL device,
Transparent substrates such as glass and plastic films are usually used. In the case of a plastic film, materials such as polycarbonate, polymethacrylate, and polysulfone are used.

The anode 2 is a transparent electrode provided on the substrate 1. As the transparent electrode, an indium tin oxide (ITO) thin film or a tin oxide film can be usually used. Further, it may be made of a metal having a large work function such as silver or gold, an inorganic conductive substance such as copper iodide, or a conductive polymer such as poly (3-methylthiophene), polypyrrole, or polyaniline.

The method of producing the anode is generally performed by a vacuum deposition method, a sputtering method, or the like. In the case of a conductive polymer, a solution with an appropriate binder is applied to the substrate. Alternatively, a thin film can be formed directly on a substrate by electrolytic polymerization. The thickness of the anode depends on the required transparency, but the visible light transmittance is 60% or more, preferably 80% or more.
It is 5 to 1000 nm, preferably 10 to 500 nm.

In the basic configuration, the light emitting layer 3 is provided on the anode 2. The light emitting layer 3 is a layer made of the above-described organic material. By using the anthracene derivative (1) for the light-emitting layer, light emission with high luminance is possible, and in particular, an organic EL device that emits light in a long wavelength region from yellow to red can be obtained. In addition, stable characteristics can be obtained over a long period of time even in continuous driving or pulse driving. The thickness of such a light emitting layer 3 is usually 10 to 200 nm, preferably 20 to 80 nm.

Various methods such as a vacuum deposition method, a dipping method, a spin coating method, and an LB method can be applied to the method for forming the light emitting layer 3. In order to produce a uniform thin film of submicron order without defects such as pinholes,
A vacuum deposition method and a spin coating method are preferred. In the vacuum evaporation method, a method of sublimating a material mixed at a certain ratio from a single boat or a crucible, a method of separately sublimating a plurality of materials from a plurality of boats, and the like can be applied. In the spin coating method, it is preferable to form a film by dissolving a plurality of materials in a solvent at a fixed ratio.

The cathode 4 is provided on the light emitting layer 3. As the cathode, various kinds of cathodes including known organic EL cathodes can be used. For example, magnesium-aluminum alloy, magnesium-silver alloy, magnesium-indium alloy,
There are aluminum-lithium alloy, aluminum and the like.
The method for producing the cathode 4 includes a vacuum deposition method, a dip method,
Various known methods such as a spin coating method, an LB method, and a CVD method can be applied. In order to produce a uniform thin film of submicron order without defects such as pinholes, a vacuum evaporation method and a spin coating method are particularly preferable.

The hole transport layer 5 is formed on the anode 2 as shown in FIG.
The light-emitting layer 3 can be provided as necessary.
As the hole transport material used for the hole transport layer 5, a material having a low hole injection barrier from the anode 2 and a high hole mobility can be used.

As such a hole transport material, a known hole transport material can be used. For example, N, N'-diphenyl-N, N'-bis (3-methylphenyl) -1,
1'-biphenyl-4,4'-diamine (hereinafter referred to as "TP
D "), aromatic diamine compounds such as 1,1'-bis (4-di-p-tolylaminophenyl) cyclohexane, and hydrazone compounds described in JP-A-2-311591. be able to. Further, polymer materials such as poly-N-vinylcarbazole and polysilane can also be preferably used (Appl. Phys.
tt., 59, 2760 (1991)).

The material of the hole transport layer 5 is not only the above organic substance but also inorganic substances such as metal chalcogenide, metal halide, metal carbide, nickel oxide, lead oxide, copper iodide, and lead sulfide. P-type compound semiconductors such as
Type hydrogenated amorphous silicon, p-type hydrogenated amorphous silicon carbide, or the like can also be used. It is also preferable to form the hole transport layer 5 by mixing the hole transport material, which is an organic substance, with such an inorganic substance.

In order to improve the heat resistance and the uniformity of the thin film of the hole transport layer 5, a binder resin which does not easily trap holes can be used by mixing with a hole transport material.
Examples of such a binder resin include polyether sulfone, polycarbonate, and polyester. The content of the binder resin is preferably from 10 to 50% by mass based on the whole material of the hole transporting layer, and if the amount is within this range, the hole mobility is less likely to be reduced.

Regardless of whether an organic substance or an inorganic substance is used, the thickness of the hole transport layer 5 is usually 10
２００200 nm, and preferably 20-80 nm.

The interface layer 6 on the anode side is provided between the anode 2 and the hole transport layer 5 to prevent leakage current, reduce the hole injection barrier,
It may be provided for the purpose of improving adhesion and the like. The material of the anode-side interface layer 6 is disclosed in Japanese Patent Application Laid-Open No. 4-308688.
No. 4,4 ', 4 "-tris {N- (3-methylphenyl) -N-phenylamino} triphenylamine (hereinafter abbreviated as" MTDATA ") which is a derivative of triphenylamine as disclosed in And 4,4 ′, 4 ″ -tris {N, N-diphenylamino} triphenylamine (hereinafter abbreviated as “TDATA”), copper phthalocyanine and the like can be preferably used. The film thickness when providing the interface layer 6 is preferably 5 to 100 nm.

The electron transport layer 7 can be provided between the light emitting layer 3 and the cathode 4 as needed. This electron transport layer 7
As the electron transporting substance, a substance having a high electron affinity and a high electron mobility is required. A substance satisfying such a condition is a cyclopentadiene derivative (JP-A 2-2).
No. 89675), oxadiazole derivatives (Japanese Unexamined Patent Publication No. 2-216793), bisstyrylbenzene derivatives (Japanese Unexamined Patent Publication No. 1-245087), p-phenylene compounds (Japanese Unexamined Patent Publication No. 3-33183), phenanthroline derivatives ( JP-A-5-331459) and triazole derivatives (JP-A-7-90260).

The interface layer 8 on the cathode side can be provided between the electron transporting layer 7 and the cathode 4 if necessary. By providing this interface layer, a reduction in driving voltage, an improvement in luminous efficiency, and a longer life can be achieved. This interface layer has the effect of facilitating electron injection from the cathode and the effect of increasing the adhesion to the cathode.

As a material of such a cathode-side interface layer 8, lithium fluoride (Appl. Phys. Lett., 70, 152 (1997))
And alkali metal oxides such as alkali metal fluorides, alkaline earth metal fluorides, magnesium oxide, strontium oxide, aluminum oxide, and lithium oxide. Organic substances such as β-diketone complexes of alkali metals and alkaline earth metals are also preferable. When such an interface layer material is itself an insulator, the thickness used is usually a thin film of 5 nm or less, and preferably 2 nm or less, so that tunnel injection of electrons from the cathode is possible. It is considered to be.

The hole transport layer 5, the interface layer 6, the electron transport layer 7, and the interface layer 8 can be formed by various known methods such as vacuum deposition, dipping, spin coating, LB, and CVD. Techniques can be applied. In order to produce a uniform thin film of submicron order without defects such as pinholes,
Particularly, a vacuum deposition method and a spin coating method are preferable.

Each of the above-described layers shown in FIGS. 1 and 2 is formed of a plurality of layers as long as it functions as an organic EL element, or another layer is sandwiched between them. May be.

In the organic EL device of the present invention, the surface of the cathode 4 and the surface of the substrate 1 are coated with a polymer film or sealed with glass to secure the storage stability and driving stability in the air. From oxygen and moisture.

The organic EL device of the present invention is used as a full-surface light emitter, used as a backlight or a wall illumination device of a liquid crystal display device, or formed by patterning pixels.
It can be used as a display.

[0049]

EXAMPLES Hereinafter, specific embodiments of the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not necessarily limited to these. The anthracene derivatives used in this example and comparative examples are shown below. In addition, the following formulas (3), (4), (6), (7), (8),
The compounds (9) and (10) are anthracene derivatives (1).

[0050]

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Example 1 (Example) An anode 2 (sheet resistance 7Ω / □) was formed on a glass substrate by depositing ITO to a thickness of 200 nm. On the anode 2, the following TPD (formula 11) was formed to a film thickness of 6 by vacuum evaporation.
The hole transport layer 5 was formed by vapor deposition to a thickness of 0 nm. Then 8
The following Al which is an aluminum complex of -oxyquinoline
q (formula 12) and the above-mentioned anthracene derivative (formula 3) are co-deposited to a film thickness of 60 nm using different boats to form a light emitting layer 3
Was formed.

At this time, in the light emitting layer of the anthracene derivative
Was 1.0 mol%. Finally, Mg and Ag
Was co-evaporated to form a 200 nm-thick MgAg (mass ratio 10:
1) A cathode alloy was formed to produce an organic EL device. Co-evaporation
The degree of vacuum when wearing is 8.0 × 10 ^-6torr.

[0053]

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Example 2 (Example) An organic EL device was produced in the same manner as in Example 1 except that the above-described anthracene derivative (Formula 4) was used instead of the anthracene derivative (Formula 3). The concentration of the anthracene derivative in the light emitting layer of this device was 1.0 mol%.

Example 3 (Comparative Example) In place of the anthracene derivative of Example 1 (formula 3), the following DC
An organic EL device was produced in the same manner as in Example 1 except that M (Formula 13) was used. The concentration of DCM in the light emitting layer of this device was 1.0 mol%.

[0056]

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Example 4 (Comparative Example) An organic EL device was prepared in the same manner as in Example 1 except that the above-described anthracene derivative (Formula 5) was used instead of the anthracene derivative (Formula 3). The concentration of the anthracene derivative in the light emitting layer of this device was 1.0 mol%.

Example 5 (Example) An organic EL device was produced in the same manner as in Example 1 except that the above-mentioned anthracene derivative (Formula 6) was used instead of the anthracene derivative (Formula 3). The concentration of the anthracene derivative in the light emitting layer of this device was 1.0 mol%.

Example 6 (Example) A solution obtained by dissolving 1 part by weight of polyvinyl carbazole and 1 part by weight of TPD in 500 parts by weight of dichloromethane was used on the anode 2 formed in the same manner as in Example 1, and the number of revolutions was 5,000 rpm.
Then, the substrate was spin-coated with a thickness of 60 nm to form a hole transport layer. Next, Alq and the above-described anthracene derivative (Formula 7) were co-evaporated to a thickness of 60 nm using different boats to form a light-emitting layer 3.

At this time, the concentration of the anthracene derivative was 1.5 mol%. Finally, an AlLi alloy (Li
A content of 0.07% by mass) was deposited to a thickness of 200 nm to form a cathode, thereby producing an organic EL device.

Example 7 (Example) The concentration of the anthracene derivative (formula 7) of Example 6 was 24 mo.
An organic EL device was produced in the same manner as in Example 6, except that the content was 1%.

Example 8 (Example) On the anode 2 formed in the same manner as in Example 1, copper phthalocyanine was deposited to a film thickness of 15 nm by a vacuum deposition method to form an interface layer 6. Next, the following NPD (formula 14) was deposited to a film thickness of 45 nm to form a hole transport layer 5.

Then, Alq and an anthracene derivative (formula 8) were co-evaporated to a thickness of 60 nm using different boats to form a light emitting layer 3. At this time, the concentration of the anthracene derivative was 1.5 mol%. Next, lithium fluoride was deposited to a thickness of 0.5 nm to form an interface layer 8. Finally, A
to a thickness of 200 nm to form a cathode 4 to form an organic E
An L element was produced.

[0064]

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Example 9 (Example) An organic EL device was produced in the same manner as in Example 8, except that the above-described anthracene derivative (Formula 9) was used instead of the anthracene derivative (Formula 8). The concentration of the anthracene derivative (Formula 9) in the light emitting layer of this device was 2.0 mol%.
Met.

Example 10 (Example) An organic EL device was produced in the same manner as in Example 8, except that the above-described anthracene derivative (Formula 10) was used instead of the anthracene derivative (Formula 8). The concentration of the anthracene derivative (formula 10) in the light emitting layer of this device was 1.5 mo
1%.

Example 11 (Evaluation) Emission color, luminous efficiency (lm / W), and driving stability (constant current of 5 mA / cm ^{2 in} nitrogen) of the organic EL devices produced in the above examples (Examples and Comparative Examples) Table 1 shows the measurement results of the time (unit: time) required for the initial luminance to drop to half of the original value when driven by.

[0068]

[Table 1]

[0069]

According to the present invention, by using a light emitting layer containing the anthracene derivative (1), it is possible to obtain an organic EL device which emits yellow to red light and has high luminous efficiency and excellent lifetime.

[Brief description of the drawings]

FIG. 1 is a side view of a basic example of an organic EL device of the present invention.

FIG. 2 is a side view of an application example of the organic EL element of the present invention.

[Explanation of symbols]

 1: substrate 2: anode 3: light emitting layer 4: cathode 5: hole transport layer 6: interface layer 7: electron transport layer 8: interface layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K007 AB03 AB04 AB11 CA01 CB01 DA01 DB03 EB00

Claims (3)

[Claims] 1. An organic electroluminescence device having a layer containing an anthracene derivative represented by the following formula (1) between an anode and a cathode. Embedded image (In the formula (1), X ¹ and X ² each independently represent an oxygen atom, a sulfur atom, an NH group or a CH ₂ group, and R ^{1 to} R 2
¹⁶ independently represents a hydrogen atom, a halogen atom or a monovalent organic group) 2. The organic electroluminescent device according to claim 1, wherein the layer is a light emitting layer containing the anthracene derivative represented by the formula (1) and another organic fluorescent substance. 3. An anthracene derivative represented by the formula (1) is contained in an amount of 0.01 to 20 mol% with respect to a total of the anthracene derivative represented by the formula (1) and another organic fluorescent substance. 3. The organic electroluminescent device according to 1.).