JP2003109765A - Organic light emitting element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic light emitting element taking on various hues, giving light of high brightness at low impressed voltage, and excellent in durability. SOLUTION: At least one of the layers consisting of organic compounds contains at least one kind of pyrazole compound or pyrazoline compound expressed in formula (I). In the formula, R1 denotes H, an alkyl group, aryl group, and a heterocyclic group, and Ar1 to Ar3 denote an aryl group, a heterocyclic group or the like.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel organic compound and an organic light emitting device using the same.

[0002]

2. Description of the Related Art In an organic light emitting device, a thin film containing a fluorescent organic compound is sandwiched between an anode and a cathode and electrons and holes are injected from each electrode to excite excitons of the fluorescent compound. It is an element that uses the light emitted when the excitons return to the ground state.

1987 Research by Kodak Company (Appl.
Phys. Lett. 51, 913 (1987)), an anode is made of ITO, a cathode is made of an alloy of magnesium and silver, an aluminum quinolinol complex is used as an electron transporting material and a light emitting material, and a triphenylamine derivative is used as a hole transporting material. 1000 cd / m ^{2 at} an applied voltage of about 10 V in a layered element
Some light emission has been reported. Related patents include US Pat. No. 4,539,507 and US Pat. No. 4,720,4.
32, US Pat. No. 4,885,211 and the like.

Further, it is possible to emit light from ultraviolet to infrared by changing the kind of the fluorescent organic compound, and recently, various compounds have been actively researched. For example, US Pat. No. 5,151,629, US Pat.
9,783, US Pat. No. 5,382,477, JP-A-2-247278, JP-A-3-255190, JP-A-5-202356, JP-A-9-202.
No. 878, Japanese Patent Laid-Open No. 9-227576, and the like.

Further, in addition to the organic light emitting device using the low molecular weight material as described above, an organic light emitting device using a conjugated polymer is also available at the group of Cambridge University (Nature,
347, 539 (1990)).
In this report, light emission is confirmed in a single layer by depositing polyphenylene vinylene (PPV) in a coating system.

As related patents of organic light-emitting devices using conjugated polymers, US Pat. No. 5,247,190, US Pat. No. 5,514,878, US Pat. No. 5,672,678.
Japanese Patent Application Laid-Open No. 4-145192 and Japanese Patent Application Laid-Open No. 5-247.
No. 460, etc. may be mentioned.

As described above, the recent progress in organic light-emitting devices is remarkable, and the feature thereof is that high-luminance at a low applied voltage, diversity of emission wavelength, high-speed response, thin and light-emitting device can be realized, It suggests the possibility of a wide range of applications.

However, under the present circumstances, further higher brightness light output or higher conversion efficiency is required. Further, there are still many problems in terms of durability such as deterioration with time due to long-term use and deterioration due to atmospheric gas containing oxygen or moisture. Furthermore, in consideration of application to a full-color display or the like, blue, green, and red light emission with good color purity is required, but these problems are still insufficient.

Aromatic compounds and condensed polycyclic aromatic compounds have been extensively studied as fluorescent organic compounds for use in electron transport layers and light emitting layers. For example, JP-A-4-6807
6, JP-A-5-32966, JP-A-6-2.
28552, JP-A-6-240244, JP-A-7-109454, and JP-A-8-31142.
JP, JP-A-9-241629, JP, 2000
JP-A-26334, JP-A-2000-268964 and the like are mentioned, but those which can sufficiently satisfy the emission brightness and durability have not been obtained.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an organic light emitting device using a specific pyrazole compound or pyrazoline compound and having extremely high efficiency and high brightness light output. Another object is to provide an extremely durable organic light emitting device. Another object is to provide an organic light emitting device that is easy to manufacture and can be manufactured at a relatively low cost.

[0011]

Therefore, the present invention is as follows.

In an organic light emitting device having at least a pair of electrodes composed of an anode and a cathode and a layer composed of one or a plurality of organic compounds sandwiched between the pair of electrodes, at least one of the layers containing the organic compound is There is provided an organic light-emitting device comprising at least one pyrazole compound represented by the general formula [I].

General formula [I]

[Outside 10]

(In the formula, R ₁ is a hydrogen atom, an alkyl group,
It represents a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group or a substituted or unsubstituted fused polycyclic heterocyclic group. . Ar ₁ , Ar ₂ and Ar ₃ are a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group. Represents Ar ₁ , Ar ₂ and Ar ₃ may be the same or different.

At least two of R ₁ , Ar ₁ , Ar ₂ and Ar ₃ represent a substituted or unsubstituted fused polycyclic aromatic group or a substituted or unsubstituted fused polycyclic heterocyclic group. ) Further, the present invention is an organic light emitting device having at least a pair of electrodes composed of an anode and a cathode, and a layer composed of one or a plurality of organic compounds sandwiched between the pair of electrodes, and at least one layer containing the organic compound. Provides an organic light-emitting device containing at least one pyrazoline compound represented by the following general formula [II].

General formula [II]

[Outside 11]

(In the formula, R ₂ is a hydrogen atom, an alkyl group,
It represents a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group or a substituted or unsubstituted fused polycyclic heterocyclic group. . Ar ₄ , Ar ₅ and Ar ₆ are a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group. Represents Ar ₄ , Ar ₅ and Ar ₆ may be the same or different.

At least two of R ₂ , Ar ₄ , Ar ₅ and Ar ₆ represent a substituted or unsubstituted fused polycyclic aromatic group or a substituted or unsubstituted fused polycyclic heterocyclic group. )

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The organic light emitting device of the present invention is an organic light emitting device having at least a pair of electrodes composed of an anode and a cathode and a layer composed of one or a plurality of organic compounds sandwiched between the pair of electrodes. At least one layer containing the organic compound contains at least one pyrazole compound represented by the following general formula [I].

General formula [I]

[Outside 12]

(In the formula, R ₁ is a hydrogen atom, an alkyl group,
It represents a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group or a substituted or unsubstituted fused polycyclic heterocyclic group. . Ar ₁ , Ar ₂ and Ar ₃ are a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group. Represents Ar ₁ , Ar ₂ and Ar ₃ may be the same or different.

At least two of R ₁ , Ar ₁ , Ar ₂ and Ar ₃ represent a substituted or unsubstituted fused polycyclic aromatic group or a substituted or unsubstituted fused polycyclic heterocyclic group. ) Further, the organic light-emitting device of the present invention is an organic light-emitting device having at least a pair of electrodes composed of an anode and a cathode, and a layer composed of one or a plurality of organic compounds sandwiched between the pair of electrodes. At least one of the layers containing contains at least one pyrazoline compound represented by the following general formula [II].

General formula [II]

[Outside 13]

(In the formula, R ₂ is a hydrogen atom, an alkyl group,
It represents a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group or a substituted or unsubstituted fused polycyclic heterocyclic group. . Ar ₄ , Ar ₅ and Ar ₆ are a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group. Represents Ar ₄ , Ar ₅ and Ar ₆ may be the same or different.

At least two of R ₂ , Ar ₄ , Ar ₅ and Ar ₆ represent a substituted or unsubstituted fused polycyclic aromatic group or a substituted or unsubstituted fused polycyclic heterocyclic group. ) The organic light-emitting device of the present invention comprises R ₁ and A of general formula [I]
At least three of r ₁ , Ar ₂ and Ar ₃ are preferably a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group.

The organic light emitting device of the present invention has the general formula [II]
R_Two, Ar_Four, Ar₅And Ar ₆At least three
Is a substituted or unsubstituted fused polycyclic aromatic group or substituted
Alternatively, it is preferably an unsubstituted condensed polycyclic heterocyclic group.
Yes.

In the organic light emitting device of the present invention, the substituted or unsubstituted fused polycyclic aromatic group is preferably a fused polycyclic aromatic group obtained by condensing three or more benzene rings.

In the organic light emitting device of the present invention, the substituted or unsubstituted fused polycyclic aromatic group is more preferably a fused polycyclic aromatic group in which four or more benzene rings are condensed.

In the organic light-emitting device of the present invention, the substituted or unsubstituted fused polycyclic aromatic group has the following general formula [III]
It is preferably a condensed polycyclic aromatic group represented by.

General formula [III]

[Outside 14]

(In the formula, R ₃ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group. In the organic light emitting device of the present invention, the substituted or unsubstituted condensed polycyclic aromatic group is preferably a condensed polycyclic aromatic group represented by the following general formula [IV].

General formula [IV]

[Outside 15]

(In the formula, R ₄ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group. In the organic light emitting device of the present invention, the substituted or unsubstituted fused polycyclic aromatic group is preferably a fused polycyclic aromatic group represented by the following general formula [V].

General formula [V]

[Outside 16]

(In the formula, R ₅ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group. In the organic light emitting device of the present invention, the substituted or unsubstituted fused polycyclic aromatic group is preferably a fused polycyclic aromatic group represented by the following general formula [VI].

General formula [VI]

[Outside 17]

(In the formula, R ₆ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group. In the organic light emitting device of the present invention, the substituted or unsubstituted condensed polycyclic aromatic group is preferably a condensed polycyclic aromatic group represented by the following general formula [VII].

General formula [VII]

[Outside 18]

(In the formula, R ₇ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group. In the organic light emitting device of the present invention, the substituted or unsubstituted condensed polycyclic aromatic group is preferably a condensed polycyclic aromatic group represented by the following general formula [VIII].

General formula [VIII]

[Outside 19]

(In the formula, R ₈ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group. In the organic light emitting device of the present invention, the substituted or unsubstituted fused polycyclic aromatic group is preferably a fused polycyclic aromatic group represented by the following general formula [IX].

General formula [IX]

[Outside 20]

(In the formula, R ₉ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group. R ₁₀ and R ₁₁ represent an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group.) The organic light emitting device of the present invention is a layer formed of an organic compound. Of these, at least the electron transport layer or the light emitting layer preferably contains at least one of the compounds represented by the general formula [I] and the general formula [II].

Specific examples of the substituents in the above general formulas [I] to [IX] are shown below.

Examples of the alkyl group include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, ter-butyl group and octyl group.

Examples of the aralkyl group include a benzyl group and a phenethyl group.

Examples of the aryl group include a phenyl group, a biphenyl group, a terphenyl group and a styryl group.

Examples of the heterocyclic group include a thienyl group, a pyrrolyl group, a pyridyl group, an oxazolyl group, an oxadiazolyl group, a thiazolyl group, a thiadiazolyl group, a terthienyl group and a terpyrrolyl group.

As the condensed polycyclic aromatic group, a naphthyl group,
Examples thereof include a fluorenyl group, anthryl group, phenanthryl group, fluoranthenyl group, pyrenyl group, tetracenyl group, pentacenyl group, perylenyl group and triphenylenyl group.

As the condensed polycyclic heterocyclic group, a quinolyl group,
Examples thereof include a carbazolyl group, an acridylyl group, and a phenanthryl group.

Examples of the substituted amino group include a dimethylamino group, a diethylamino group, a dibenzylamino group, a diphenylamino group, a ditolylamino group, a dianisolylamino group and a julolidyl group.

Examples of the substituent which the above substituent may have include an alkyl group such as a methyl group, an ethyl group and a propyl group, an aralkyl group such as a benzyl group and a phenethyl group, a phenyl group, a biphenyl group, a terphenyl group, Heterocyclic group such as aryl group such as styryl group, thienyl group, pyrrolyl group, pyridyl group, oxazolyl group, oxadiazolyl group, thiazolyl group, thiadiazolyl group, terthienyl group, terpyrrolyl group, naphthyl group, fluorenyl group, anthryl group, phenanthryl group , Fluoranthenyl group, pyrenyl group, tetracenyl group, pentacenyl group, perylenyl group, condensed polycyclic aromatic group such as triphenylenyl group, quinolyl group, carbazolyl group, acridylyl group, condensed polycyclic heterocyclic group such as phenanthryl group, dimethyl Amino group, diethylamino group, Benzylamino group, diphenylamino group, ditolylamino group, a dianisolylamino group, a substituted amino group such as julolidyl group, methoxyl group, ethoxyl group, propoxyl group, an alkoxyl group such as phenoxyl group, and a cyano group.

Next, typical examples of the condensed polycyclic compound of the present invention are shown below, but the present invention is not limited thereto.

[Example of Compound of this Embodiment]

[Outside 21]

[0055]

[Outside 22]

[0056]

[Outside 23]

[0057]

[Outside 24]

[0058]

[Outside 25]

[0059]

[Outside 26]

[0060]

[Outside 27]

[0061]

[Outside 28]

The pyrazoline compound of the present invention can be synthesized by a generally known method, for example, a cycloaddition reaction between a hydrazine compound and a chalcone compound (for example, J. Mate).
r. Chem. , 1999, 9, 1077) and the like.

The pyrazole compound of the present invention can be synthesized by aromatizing the pyrazoline compound obtained by the above method with palladium carbon or the like.

The general formula [I] and the general formula [I
The pyrazole compound and the pyrazoline compound represented by the formula I] are compounds having excellent electron transporting property, light emitting property and durability as compared with conventional compounds, and are layers containing an organic compound of an organic light emitting device, particularly an electron transporting layer and a light emitting layer. It is useful as a layer, and a layer formed by a vacuum vapor deposition method, a solution coating method or the like is less likely to be crystallized and has excellent stability over time.

Next, the organic light emitting device of the present invention will be described in detail.

The organic light emitting device of the present invention is an organic light emitting device having at least a pair of electrodes consisting of an anode and a cathode and a layer containing one or a plurality of organic compounds sandwiched between the pair of electrodes. At least one layer containing a compound contains at least one of a pyrazole compound and a pyrazoline compound represented by the general formula [I] and the general formula [II].

In the organic light emitting device of the present invention, it is preferable that at least the electron transport layer or the light emitting layer among the layers containing the organic compound contains at least one of the pyrazole compound and the pyrazoline compound.

In the organic light emitting device of the present invention, the pyrazole compound and the pyrazoline compound represented by the above general formulas [I] and [II] are formed between the anode and the cathode by a vacuum deposition method or a solution coating method. The thickness of the organic layer is thinner than 10 μm, preferably 0.5 μm or less, and more preferably 0.01 to 0.5 μm.

1 to 6 show preferred examples of the organic light emitting device of the present invention.

FIG. 1 is a sectional view showing an example of the organic light emitting device of the present invention. FIG. 1 shows a structure in which an anode 2, a light emitting layer 3 and a cathode 4 are sequentially provided on a substrate 1. The light emitting device used here is useful when it has a single hole transporting ability, an electron transporting ability and a light emitting ability by itself, or when a compound having each characteristic is mixed and used.

FIG. 2 is a sectional view showing another example of the organic light emitting device of the present invention. In FIG. 2, an anode 2, a hole transport layer 5, an electron transport layer 6 and a cathode 4 are sequentially provided on a substrate 1. In this case, when the light-emitting substance has a hole-transporting property, an electron-transporting property, or both, is used for each layer, and is used in combination with a mere hole-transporting substance or electron-transporting substance having no light-emitting property. Useful for. In this case, the light emitting layer 3 is composed of either the hole transport layer 5 or the electron transport layer 6.

FIG. 3 is a sectional view showing another example of the organic light emitting device of the present invention. FIG. 3 shows a structure in which an anode 2, a hole transport layer 5, a light emitting layer 3, an electron transport layer 6 and a cathode 4 are sequentially provided on a substrate 1. This separates the functions of carrier transport and light emission, and is used in combination with a compound having hole transporting property, electron transporting property, and light emitting property in a timely manner to greatly increase the degree of freedom in material selection and to increase the emission wavelength. Since various compounds having different colors can be used, it is possible to diversify the emission hue.

Further, it becomes possible to effectively confine each carrier or exciton in the central light emitting layer to improve the light emitting efficiency.

FIG. 4 is a sectional view showing another example of the organic light emitting device of the present invention. FIG. 4 shows a structure in which the hole injection layer 7 is inserted on the anode side as compared with FIG. 3, and it is effective in improving the adhesion between the anode and the hole transport layer or the hole injection property, and is effective in lowering the voltage. .

5 and 6 are cross-sectional views showing another example of the organic light emitting device of the present invention. 5 and 6 show
3 and 4, a layer (hole blocking layer 8) that prevents holes or excitons (excitons) from exiting to the cathode side is inserted between the light emitting layer and the electron transporting layer. By using a compound having a very high ionization potential as the hole blocking layer 8, the structure is effective for improving the luminous efficiency.

However, FIGS. 1 to 6 show only a very basic device structure, and the structure of the organic light emitting device using the compound of the present invention is not limited to these. For example,
An insulating layer is provided at the interface between the electrode and the organic layer, and an adhesive layer or an interference layer is provided. The hole transport layer is composed of two layers having different ionization potentials. Various layer configurations can be adopted.

The pyrazole compounds and pyrazoline compounds represented by the general formulas [I] and [II] used in the present invention are excellent in electron transporting property, light emitting property and durability as compared with conventional compounds, Any of the forms shown in FIGS. 1 to 6 can be used.

In particular, the organic layer using the pyrazole compound and the pyrazoline compound of the present invention is useful as an electron transport layer and a light emitting layer, and a layer formed by a vacuum vapor deposition method or a solution coating method causes crystallization or the like. It is difficult and has excellent stability over time.

The present invention uses the pyrazole compound and the pyrazoline compound represented by the general formulas [I] and [II] as the constituent components of the electron transport layer and the light emitting layer. A transporting compound, a light emitting compound, an electron transporting compound or the like can be used together as necessary.

Examples of these compounds are given below.

Hole-transporting compound

[Outside 29]

Electron-transporting light-emitting material

[Outside 30]

Luminescent material

[Outside 31]

Emitting Layer Matrix Material and Electron Transport Material

[Outside 32]

Polymeric hole-transporting material

[Outside 33]

Polymer-based light-emitting material and charge-transporting material

[Outside 34]

In the organic light emitting device of the present invention, the layer containing the pyrazole compound and the pyrazoline compound represented by the general formulas [I] and [II] and the layer containing other organic compound are generally formed by a vacuum vapor deposition method. Alternatively,
It is dissolved in a suitable solvent to form a thin film by a coating method.
In particular, when the film is formed by the coating method, the film can be formed by combining with an appropriate binder resin.

The binder resin can be selected from a wide range of binder resins such as polyvinyl carbazole resin,
Polycarbonate resin, polyester resin, polyarylate resin, polystyrene resin, acrylic resin, methacrylic resin, butyral resin, polyvinyl acetal resin,
Examples thereof include diallyl phthalate resin, phenol resin, epoxy resin, silicone resin, polysulfone resin, and urea resin, but are not limited thereto. Further, these may be used alone or as a copolymer polymer, or one or more kinds thereof may be mixed.

As the anode material, a material having a work function as large as possible is preferable. For example, simple metals such as gold, platinum, nickel, palladium, cobalt, selenium and vanadium or alloys thereof, tin oxide, zinc oxide, indium tin oxide ( A metal oxide such as ITO) or zinc indium oxide can be used. In addition, conductive polymers such as polyaniline, polypyrrole, polythiophene, and polyphenylene sulfide can also be used. These electrode substances may be used alone or in combination of two or more.

On the other hand, as the cathode material, one having a small work function is preferable, and lithium, sodium, potassium, calcium, magnesium, aluminum, indium, silver,
It can be used as a simple metal or a plurality of alloys of lead, tin, chromium and the like. It is also possible to use a metal oxide such as indium tin oxide (ITO). The cathode may have a single layer structure or a multilayer structure.

The substrate used in the present invention is not particularly limited, but an opaque substrate such as a metal substrate or a ceramic substrate, or a transparent substrate such as glass, quartz or a plastic sheet is used. Further, it is also possible to control the emitted light by using a color filter film, a fluorescent color conversion filter film, a dielectric reflection film or the like on the substrate.

A protective layer or a sealing layer may be provided on the produced element for the purpose of preventing contact with oxygen, moisture or the like. Examples of the protective layer include an inorganic material film such as a diamond thin film, a metal oxide and a metal nitride, a polymer film such as a fluorine resin, polyparaxylene, polyethylene, a silicone resin and a polystyrene resin, and a photocurable resin. To be It is also possible to cover the glass, gas impermeable film, metal, etc., and package the element itself with a suitable sealing resin.

[0093]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Synthesis Example 1 Exemplified Compound No. 25. Synthesis of 25 into 1-acetylpyrene 7.
8 g (31.9 mmol), 50 ml of ethanol and 50 ml of THF were added, and a solution of 1.9 g (33.8 mmol) of potassium hydroxide in 10 ml of water was added dropwise under stirring at room temperature. After stirring for 1 hour, a solution of 1-pyrenecarboxaldehyde (7.0 g, 30.4 mmol) in THF (30 ml) was added dropwise. After stirring at room temperature for 5 hours, the precipitated crystals were collected by filtration, washed with methanol and hexane, and dried to obtain 8.9 g (yield 64%) of orange crystal 1.

In a 200 ml three-necked flask, 1 2.0
g (4.4 mmol), ethanol 20 ml and TH
F80 ml, then phenylhydrazine 1.4 g (1
(3.0 mmol) and then refluxed for 8 hours. The reaction solution was extracted with toluene, dried and purified by a silica gel column to obtain 1.4 g (yield 46%) of orange crystals (Exemplified Compound No. 25).

[Outside 35]

Synthesis Example 2 Exemplified Compound No. Example 1 was added to a synthetic 100 ml three-necked flask. 25
1.0 g (1.8 mmol), 0.2% of 10% palladium carbon and 30 ml of decalin were added, and the mixture was stirred at 180 ° C. for 3 hours. The reaction solution was filtered, and the filtrate was purified by a silica gel column to give white crystals (Exemplified Compound No. 1) 0.7.
g (yield 71%) was obtained.

[Outside 36]

Example 1 A device having the structure shown in FIG. 2 was prepared.

On a glass substrate as the substrate 1, indium tin oxide (ITO) as the anode 2 was formed by sputtering 1
The film having a film thickness of 20 nm was used as a transparent conductive support substrate. This was sequentially ultrasonically washed with acetone and isopropyl alcohol (IPA), then washed by boiling with IPA and then dried. Furthermore, what was washed with UV / ozone was used as a transparent conductive support substrate.

A chloroform solution of a compound represented by the following structural formula was formed into a film having a thickness of 30 nm on a transparent conductive support substrate by a spin coating method to form a hole transport layer 5.

[Outside 37]

Further, the exemplified compound No. Pillar 1
Film formation of sol compound by vacuum evaporation method to a film thickness of 50 nm
Then, the electron transport layer 6 was formed. The degree of vacuum during vapor deposition is 1.0 ×
10 ^-4Pa, film formation rate is 0.2 to 0.3 nm / sec
The film was formed under the above condition.

Next, as the cathode 4, a vapor deposition material composed of aluminum and lithium (lithium concentration 1 atom%) was used, and a thickness of 150 n was formed on the above organic layer by a vacuum vapor deposition method.
m metal layer film was formed. The degree of vacuum during vapor deposition is 1.0 x 1
The film was formed under the conditions of 0 ⁻⁴ Pa and the film forming rate of 1.0 to 1.2 nm / sec.

When a DC voltage of 10 V was applied to the element thus obtained, with the ITO electrode (anode 2) as a positive electrode and the Al-Li electrode (cathode 4) as a negative electrode, 8.0 mA / cm 2 was applied.
Current flows through the element at a ^second current density, 3900cd / ^{m 2}
A blue emission was observed at the brightness of.

Further, the current density is 5.0 in a nitrogen atmosphere.
When the voltage was applied for 100 hours while maintaining the current at mA / cm ² ,
Initial brightness of 1500 cd / m ² to 100 after 100 hours
The luminance deterioration was as small as cd / m ² .

[Examples 2 to 15] Exemplified Compound No. In place of 1, exemplified compound No. 3,5,7,12,15,1
7, 18, 23, 27, 30, 36, 41, 45, 48
A device was prepared in the same manner as in Example 1 except that was used, and the same evaluation was performed.

The results are shown in Table 1.

[Comparative Examples 1 to 6] Exemplified Compound No. A device was prepared in the same manner as in Example 1 except that the compound represented by the following structural formula was used instead of 1, and the same evaluation was performed.

The results are shown in Table 1.

Comparative compound No. 1

[Outside 38]

Comparative compound No. Two

[Outside 39]

Comparative Compound No. Three

[Outside 40]

Comparative compound No. Four

[Outside 41]

Comparative Compound No. 5

[Outside 42]

Comparative Compound No. 6

[Outside 43]

[0114]

[Table 1]

Example 16 An element having the structure shown in FIG. 3 was prepared.

As in Example 1, the hole transport layer 5 was formed on the transparent conductive support substrate.

Further, Exemplified Compound No. The pyrazole compound represented by 6 was formed into a film with a thickness of 20 nm by a vacuum evaporation method to form a light emitting layer 3. The degree of vacuum during vapor deposition is 1.0 x 10
^The film was formed under the conditions of ⁻⁴ Pa and a film forming rate of 0.2 to 0.3 nm / sec.

Further, aluminum trisquinolinol was formed into a film with a thickness of 40 nm by a vacuum evaporation method to form an electron transport layer 6.
Was formed. The degree of vacuum during vapor deposition is 1.0 × 10 ⁻⁴ Pa,
The film was formed at a film forming speed of 0.2 to 0.3 nm / sec.

Next, as the cathode 4, a vapor deposition material composed of aluminum and lithium (lithium concentration 1 atom%) was used, and a thickness of 150 n was formed on the above organic layer by a vacuum vapor deposition method.
A metal layer film of m was formed, and an element having the structure shown in FIG. 3 was prepared. The degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 1.0 to 1.2 nm / sec.

When an ITO electrode (anode 2) was used as a positive electrode and an Al-Li electrode (cathode 4) was used as a negative electrode and a DC voltage of 8 V was applied to the device thus obtained, 9.8 mA / cm ²
A current flowed through the device at a current density of, and blue light emission was observed at a luminance of 5,800 cd / m ² .

Further, the current density is 7.0 in a nitrogen atmosphere.
When the voltage was applied for 100 hours while maintaining the current at mA / cm ² ,
Initial brightness 2800 cd / m ² to 100 after 100 hours 2400
The luminance deterioration was as small as cd / m ² .

[Examples 17 to 30] Exemplified Compound No. 6
Instead of the exemplified compound No. 8, 10, 14, 19, 2
4,26,31,33,35,38,42,43,4
A device was prepared in the same manner as in Example 16 except that 4, 47 were used, and the same evaluation was performed.

The results are shown in Table-2.

Comparative Examples 7 to 12 Exemplified Compound No. 6 in place of Comparative Compound No. An element was prepared in the same manner as in Example 16 except that 1, 2, 3, 4, 5, 6 were used, and the same evaluation was performed.

The results are shown in Table 2.

[0126]

[Table 2]

Example 31 An element having the structure shown in FIG. 3 was prepared.

On the same transparent conductive supporting substrate as in Example 1, a hole-transporting layer 5 was formed by spin-coating a chloroform solution of a compound represented by the following structural formula to a film thickness of 20 nm.

[Outside 44]

Further, the compound represented by the following structural formula and the exemplified compound No. A light emitting layer 3 was formed by depositing a pyrazole compound represented by 1 (weight ratio 1:50) with a film thickness of 20 nm by a vacuum deposition method. The degree of vacuum during vapor deposition is 1.0 x 10
^The film was formed under the conditions of ⁻⁴ Pa and a film forming rate of 0.2 to 0.3 nm / sec.

[Outside 45]

Further, aluminum trisquinolinol was formed into a film with a thickness of 40 nm by a vacuum evaporation method to form an electron transport layer 6.
Was formed. The degree of vacuum during vapor deposition is 1.0 × 10 ⁻⁴ Pa,
The film was formed at a film forming speed of 0.2 to 0.3 nm / sec.

Next, as the cathode 4, a vapor deposition material composed of aluminum and lithium (lithium concentration 1 atom%) was used, and a thickness of 150 n was formed on the above organic layer by a vacuum vapor deposition method.
A metal layer film of m was formed, and an element having the structure shown in FIG. 3 was prepared. The degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 1.0 to 1.2 nm / sec.

When an ITO electrode (anode 2) was used as a positive electrode and an Al-Li electrode (cathode 4) was used as a negative electrode and a DC voltage of 8 V was applied to the device thus obtained, 9.3 mA / cm ²
Current flows through the device at a current density of 53000 cd / m ²
A blue emission was observed at the brightness of.

Furthermore, the current density is set to 5.0 in a nitrogen atmosphere.
When the voltage was applied for 100 hours while maintaining the current at mA / cm ² ,
Initial brightness 26000 cd / m ² to 100 hours later 210
The luminance deterioration was as small as 00 cd / m ² .

[Examples 32 to 45] Exemplified Compound No. 1
Instead of the exemplified compound No. 4,9,11,16,2
0, 21, 22, 28, 29, 32, 34, 39, 4
A device was prepared in the same manner as in Example 31 except that 0 and 46 were used, and the same evaluation was performed. The results are shown in Table-3.

[Comparative Examples 13 to 18] Exemplified Compound No. 1
Instead of Comparative Compound No. A device was prepared in the same manner as in Example 31 except that 1, 2, 3, 4, 5, and 6 were used, and the same evaluation was performed.

The results are shown in Table 3.

[0137]

[Table 3]

Example 46 An element having the structure shown in FIG. 1 was prepared.

On the transparent conductive support substrate similar to that of Example 1, the exemplified compound No. A solution of 0.050 g of the pyrazole compound represented by 2 and 1.00 g of poly-N-vinylcarbazole (weight average molecular weight = 63,000) in 80 ml of chloroform was spin-coated (rotation number =
A film having a thickness of 120 nm was formed at 2000 rpm) to form an organic layer (light emitting layer 3).

Next, as the cathode 4, a vapor deposition material composed of aluminum and lithium (lithium concentration 1 atom%) was used, and a thickness of 150 n was formed on the above organic layer by a vacuum vapor deposition method.
A metal layer film of m was formed to produce a device having the structure shown in FIG. The degree of vacuum at the time of vapor deposition was 1.0 × 10 ⁻⁴ Pa, and the film formation rate was 1.0 to 1.2 nm / sec.

When the ITO electrode (anode 2) was used as a positive electrode and the Al—Li electrode (cathode 4) was used as a negative electrode, a DC voltage of 10 V was applied to the device thus obtained, and then 7.5 mA / cm 2 was applied.
Current flows through the element at a ^second current density, 2500 cd / ^{m 2}
A blue emission was observed at the brightness of.

Furthermore, the current density is set to 5.0 in a nitrogen atmosphere.
When the voltage was applied for 100 hours while maintaining the current at mA / cm ² ,
Initial brightness of 1400 cd / m ² to 1200 after 100 hours
The luminance deterioration was as small as cd / m ² .

[Examples 47 to 50] Exemplified Compound No. Two
Instead of the exemplified compound No. A device was prepared in the same manner as in Example 46 except that 13, 20, 25 and 37 were used, and the same evaluation was performed. The results are shown in Table-4.

[Comparative Examples 19 to 24] Exemplified Compound No. Two
Instead of Comparative Compound No. An element was prepared in the same manner as in Example 46 except that 1, 2, 3, 4, 5, 6 were used, and the same evaluation was performed.

The results are shown in Table 4.

[0146]

[Table 4]

[0147]

As described above, the organic light emitting device using the pyrazole compound or the pyrazoline compound represented by the general formula [I] or the general formula [II] can obtain high-luminance light emission at a low applied voltage, It also has excellent durability. In particular, the organic layer containing the fused polycyclic compound of the present invention is excellent as an electron transport layer and also as a light emitting layer.

Further, the element can be formed by using the vacuum deposition method or the casting method, and the element having a relatively large area and a large area can be easily formed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an organic light emitting device according to the present invention.

FIG. 2 is a cross-sectional view showing another example of the organic light emitting device according to the present invention.

FIG. 3 is a cross-sectional view showing another example of the organic light emitting device according to the present invention.

FIG. 4 is a cross-sectional view showing another example of the organic light emitting device according to the present invention.

FIG. 5 is a cross-sectional view showing another example of the organic light emitting device according to the present invention.

FIG. 6 is a cross-sectional view showing another example of the organic light emitting device according to the present invention.

[Explanation of symbols]

1 substrate 2 anode 3 light emitting layer 4 cathode 5 hole transport layer 6 Electron transport layer 7 hole injection layer 8 holes / exciton blocking layer

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 33/22 H05B 33/22 B (72) Inventor Akihiro Senoo 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F term (reference) 3K007 AB02 AB03 AB11 DB03

Claims (14)

[Claims] 1. An organic light-emitting device comprising at least a pair of electrodes composed of an anode and a cathode and a layer composed of one or a plurality of organic compounds sandwiched between the pair of electrodes, wherein at least one layer containing the organic compound is at least one layer. Which contains at least one of the pyrazole compounds represented by the following general formula [I]. General formula [I] (In the formula, R ₁ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group. Or a substituted or unsubstituted fused polycyclic heterocyclic group, Ar ₁ , Ar ₂ and Ar
₃ represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group. Ar ₁ , Ar ₂ and Ar ₃ may be the same or different. R ₁ , Ar ₁ , Ar ₂ and Ar
_At least two of ₃ represent a substituted or unsubstituted fused polycyclic aromatic group or a substituted or unsubstituted fused polycyclic heterocyclic group. ) 2. An organic light emitting device comprising at least a pair of electrodes composed of an anode and a cathode and a layer composed of one or a plurality of organic compounds sandwiched between the pair of electrodes, and at least one layer containing the organic compound. Is an organic light-emitting device containing at least one pyrazoline compound represented by the following general formula [II]. General formula [II] (In the formula, R ₂ is a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group Or a substituted or unsubstituted fused polycyclic heterocyclic group, Ar ₄ , Ar ₅ and Ar
₆ represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group. Ar ₄ , Ar ₅ and Ar ₆ may be the same or different. R ₂ , Ar ₄ , Ar ₅ and Ar
_At least two of ₆ represent a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group. ) _{3. At} least three of R ₁ , Ar ₁ , Ar ₂ and Ar ₃ of the general formula [I] are substituted or unsubstituted fused polycyclic aromatic groups or substituted or unsubstituted fused polycyclic heterocyclic groups. The organic light emitting device according to claim 1, wherein 4. R ₂ , Ar ₄ and Ar _{5 of the} general formula [II].
The organic light emitting device according to claim 2, wherein at least three of Ar ₆ and Ar ₆ are a substituted or unsubstituted condensed polycyclic aromatic group or a substituted or unsubstituted condensed polycyclic heterocyclic group. 5. The organic compound according to claim 1, wherein the substituted or unsubstituted condensed polycyclic aromatic group is a condensed polycyclic aromatic group in which three or more benzene rings are condensed. Light emitting element. 6. The organic compound according to claim 1, wherein the substituted or unsubstituted condensed polycyclic aromatic group is a condensed polycyclic aromatic group in which four or more benzene rings are condensed. Light emitting element. 7. The organic light emitting device according to claim 5, wherein the substituted or unsubstituted fused polycyclic aromatic group is a fused polycyclic aromatic group represented by the following general formula [III]. General formula [III] (In the formula, R ₃ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group.) 8. The organic light emitting device according to claim 5, wherein the substituted or unsubstituted fused polycyclic aromatic group is a fused polycyclic aromatic group represented by the following general formula [IV]. General formula [IV] (In the formula, R ₄ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group.) 9. The organic light emitting device according to claim 5, wherein the substituted or unsubstituted fused polycyclic aromatic group is a fused polycyclic aromatic group represented by the following general formula [V]. General formula [V] (In the formula, R ₅ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group.) 10. The organic light emitting device according to claim 6, wherein the substituted or unsubstituted fused polycyclic aromatic group is a fused polycyclic aromatic group represented by the following general formula [VI]. General formula [VI] (In the formula, R ₆ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group.) 11. The organic light emitting device according to claim 6, wherein the substituted or unsubstituted fused polycyclic aromatic group is a fused polycyclic aromatic group represented by the following general formula [VII]. General formula [VII] (In the formula, R ₇ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group.) 12. The organic light emitting device according to claim 6, wherein the substituted or unsubstituted fused polycyclic aromatic group is a fused polycyclic aromatic group represented by the following general formula [VIII]. General formula [VIII] (In the formula, R ₈ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group.) 13. The substituted or unsubstituted fused polycyclic aromatic group is a fused polycyclic aromatic group represented by the following general formula [IX], wherein: Organic light emitting device. General formula [IX] (In the formula, R ₉ represents a hydrogen atom, an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted amino group or a cyano group. R ₁₀ , R ₁₁ represents an alkyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group.) 14. A layer comprising an organic compound, wherein at least an electron transport layer or a light emitting layer contains at least one compound represented by the general formula [I] and the general formula [II]. And the organic light emitting device according to 2.