JP2002134275A - Light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a red color light emitting device having high luminosity and high color purity. SOLUTION: The light emitting device contains a pyromethene compound of a formula 1 or its metal complex. R1 to R3 are such, they may be the same or differ, hydrogen, alkyl, cycloalkyl, aralkyl, alkenyl, cycloalkenyl, cycloalkinyl, hydroxyl group, mercapte, alkoxy, alkylthio, arylether, arylthioether, aryl, heterocyclic-ring group, halogen, haloalkane, haloalkene, haloalkyne, cyano, aldehyde, carbonyl, carboxyl, ester, a carbamoyl, amino, nitro, silyl, siloxanyl group, or aromatic group, fatty series, or condenced ring of heterocyclic ring formed between adjacent substitution groups. X1 and X2 may be the same or may differ, show single bond, substituted/nonsubstituted alkylene bond, ether bond, sulfide bond, substituted/nonsubstituted amino bond, ester bond or carbonyl bond. Ar1 and Ar2 express substituted/nonsubstited aryl group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an element capable of converting electric energy into light, and relates to a display element, a flat panel display, a backlight, lighting, an interior, a sign, a sign, an electrophotographic device, an optical signal generator, and the like. The present invention relates to a light emitting element that can be used in the field of (1).

[0002]

2. Description of the Related Art In recent years, studies have been actively conducted on organic laminated thin-film light emitting devices in which electrons injected from a cathode and holes injected from an anode emit light when they recombine in an organic phosphor sandwiched between both electrodes. ing. This device has attracted attention because it is thin, emits light with high luminance under a low driving voltage, and emits multicolor light by selecting a fluorescent material.

[0003] This study was conducted by Kodak Corporation. W. Tang
Et al. Have shown that an organic laminated thin film element emits light with high luminance (Appl. Phys. Lett. 51 (12) 2).
1, p. 913, 1987), and many research institutions are conducting studies. A typical configuration of an organic layered thin-film light emitting device presented by a research group of Kodak Company is a diamine compound having a hole transporting property on an ITO glass substrate, 8-hydroxyquinoline aluminum as a light emitting layer, and M as a cathode.
g: Ag was sequentially provided, and green light emission of 1000 cd / m ² was possible at a driving voltage of about 10 V. The present organic laminated thin-film light-emitting device has a different configuration, such as a device provided with an electron transport layer in addition to the above-described device components, but basically follows the configuration of Kodak Company.

[0004] Among multicolor light emission, red light emission has been studied as a useful light emission color. Conventionally, perylene-based such as bis (diisopropylphenyl) perylene, perinone-based, porphyrin-based, Eu complex (Chem. Let
t. , 1267 (1991)) are known as red light emitting materials.

As a technique for obtaining red light emission, a method of mixing a small amount of a red fluorescent material as a dopant into a host material is also being studied. As the host material, tris (8-quinolinolato) aluminum complex, bis (1
0-benzoquinolinolato) beryllium complex, diarylbutadiene derivative, stilbene derivative, benzoxazole derivative, benzothiazole derivative and the like,
4- (dicyanomethylene)-as a dopant therein
2-methyl-6- (p-dimethylaminostyryl) -4
H-pyran, metal phthalocyanine (MgPc, AlPc
Cl), a squarylium compound, and a biolanthrone compound were used to emit red light.

Further, as a light emitting material, in particular, as a dopant material, a pyromethene compound which is a compound exhibiting high luminance emission is known (Japanese Patent Application Laid-Open No. Hei 9-118880). It is also known that a red light is emitted by introducing an aromatic ring or the like into a pyrromethene skeleton (Japanese Patent Laid-Open No. 2000-2082).
No. 65).

[0007]

There are many luminescent materials (host materials and dopant materials) used in the prior art, which have low luminous efficiency and high power consumption, and have low compound durability and short element life. Was. Among the three primary colors required for a full-color display, high-performance light-emitting materials have been found for green light emission, but blue and red, especially red, have sufficient characteristics, especially both high brightness and high color purity. No luminescent material has been obtained. The present invention
It is an object of the present invention to solve the problems of the prior art and to provide a red light emitting device having high luminous efficiency and excellent color purity.

[0008]

That is, the present invention relates to an element which emits light by electric energy, in which a light emitting substance is present between an anode and a cathode, wherein the element is a pyrromethene compound represented by the general formula (1). Alternatively, a light-emitting element including a metal complex thereof is provided.

[0009]

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(Here, R ^{1 to} R ³ may be the same or different, and may be hydrogen, alkyl, cycloalkyl, aralkyl, alkenyl, cycloalkenyl, alkynyl, hydroxyl, mercapto, alkoxy, etc.) Group, alkylthio group, arylether group, arylthioether group, aryl group, heterocyclic group, halogen, haloalkane, haloalkene, haloalkyne, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group Group, silyl group,
It is selected from a siloxanyl group and an aromatic, aliphatic or heterocyclic condensed ring formed between adjacent substituents. X ¹ and X ² may be the same or different and each is a single bond, a substituted or unsubstituted alkylene bond, an ether bond, a sulfide bond, a substituted or unsubstituted amino bond, a substituted or unsubstituted amide bond, or an ester bond. Or a carbonyl bond. Ar ¹ and Ar ^{2 each} represent a substituted or unsubstituted aryl group. )

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the anode is made of a conductive metal oxide such as tin oxide, indium oxide, indium tin oxide (ITO) or a metal such as gold, silver or chromium if it is transparent to extract light. Although not particularly limited, such as metals, inorganic conductive substances such as copper iodide and copper sulfide, and conductive polymers such as polythiophene, polypyrrole, and polyaniline, it is particularly preferable to use ITO glass or Nesa glass. The resistance of the transparent electrode is not limited as long as a current sufficient for light emission of the element can be supplied, but is preferably low from the viewpoint of power consumption of the element. For example, 3
Although an ITO substrate having a resistance of 00 Ω / □ or less functions as an element electrode, a substrate having a resistance of about 10 Ω / □ can be supplied at present. The thickness of the ITO can be arbitrarily selected according to the resistance value, but is usually used in a range of usually 100 to 300 nm. Further, the glass substrate is made of soda lime glass, non-alkali glass, or the like, and the thickness only needs to be sufficient to maintain the mechanical strength.
mm or more is sufficient. For the glass material,
Alkali-free glass is preferred because less ions elute from the glass is preferred, but soda-lime glass with a barrier coat such as SiO ₂ is also commercially available and can be used. The method of forming the ITO film is not particularly limited, such as an electron beam method, a sputtering method, and a chemical reaction method.

The cathode is not particularly limited as long as it can efficiently inject electrons into the organic material layer.
Gold, silver, copper, iron, tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, calcium, magnesium, etc., and lithium, sodium for improving the electron injection efficiency and improving the device characteristics , Potassium, calcium, magnesium or alloys containing these low work function metals are effective. But,
These low work function metals are generally unstable in the air in many cases. For example, an organic layer is doped with a very small amount of lithium or magnesium (1 nm or less as indicated by a film thickness gauge by vacuum deposition) to have high stability. Although a method using an electrode can be mentioned as a preferable example, it is not particularly limited because an inorganic salt such as lithium fluoride can be used. In addition, platinum, gold,
Lamination of metals such as silver, copper, iron, tin, aluminum, and indium, or alloys using these metals, and inorganic substances such as silica, titania, and silicon nitride, polyvinyl alcohol, vinyl chloride, and hydrocarbon polymers. Are preferred examples. The method for producing these electrodes is not particularly limited, as long as electrical conduction such as resistance heating, electron beam, sputtering, ion plating, and coating can be achieved.

The luminescent substance includes: 1) a hole transport layer / a luminescent layer,
2) hole transport layer / light emitting layer / electron transport layer, 3) light emitting layer / electron transport layer, 4) hole transport layer / light emitting layer / hole blocking layer, 5)
A hole transporting layer / a light emitting layer / a hole blocking layer / an electron transporting layer; 6) a light emitting layer / a hole blocking layer / an electron transporting layer; Is also good. That is, as the element configuration, in addition to the multilayer laminated structure of the above 1) to 6), only a layer containing a luminescent material alone or a layer containing a luminescent material and a hole transporting material or an electron transporting material as in 7) may be provided. Further, the luminescent substance in the present invention corresponds to both a substance which emits light by itself and a substance which assists the light emission, and refers to a compound, a layer, or the like involved in light emission.

The hole transporting layer is formed by a hole transporting substance alone or by laminating and mixing two or more kinds of substances or by a mixture of a hole transporting substance and a polymer binder. N, N'-diphenyl-N, N'-di (3-methylphenyl) -4,4'-diphenyl-1,1'-diamine, N, N'-dinaphthyl-N, N'-diphenyl-
Triphenylamines such as 4,4′-diphenyl-1,1′-diamine, bis (N-allylcarbazole) or bis (N-alkylcarbazole), pyrazoline derivatives, stilbene compounds, hydrazone compounds, oxadi Heterocyclic compounds represented by azole derivatives, phthalocyanine derivatives, porphyrin derivatives, and polymer-based polycarbonates and styrene derivatives having the above monomers in the side chain, polyvinylcarbazole, polysilane, and the like are preferable. However, the compound is not particularly limited as long as it can inject holes from the anode and can transport holes.

The light emitting material may be either a host material alone or a combination of a host material and a dopant material. In addition, the dopant material may be included in the entire host material, partially, or may be included. The dopant material may be stacked, dispersed, or the like.

Hitherto, it has been known that a pyrromethene compound emits high-luminance light as a light-emitting material, particularly as a dopant material, and it is also known that an aromatic ring or the like is introduced into a pyrromethene skeleton to emit red light. ing. However, red light emission satisfying both the light emission luminance and chromaticity has not been obtained. Therefore, in the pyrromethene compound of the present invention, an aromatic ring (Ar ¹ and Ar ^{2 in} the general formula (1)) introduced into the pyrromethene skeleton to obtain red light emission is fixed to the pyromethene skeleton by a chemical bond. Thereby, the fluorescence quantum yield of the pyrromethene compound is improved, and the half width of the emission spectrum is narrowed, so that red light emission with high luminance and high color purity can be obtained. Examples of the pyromethene compound include a compound represented by the following general formula (1) or a metal complex thereof.

[0017]

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Here, R ^{1 to} R ³ may be the same or different, and may be hydrogen, alkyl, cycloalkyl, aralkyl, alkenyl, cycloalkenyl, alkynyl, hydroxyl, mercapto, alkoxy. , Alkylthio, arylether, arylthioether, aryl, heterocyclic, halogen, haloalkane, haloalkene, haloalkyne, cyano, aldehyde, carbonyl, carboxyl, ester, carbamoyl, amino, nitro , A silyl group,
It is selected from a siloxanyl group and an aromatic, aliphatic or heterocyclic condensed ring formed between adjacent substituents. X ¹ and X ² may be the same or different and each is a single bond, a substituted or unsubstituted alkylene bond, an ether bond, a sulfide bond, a substituted or unsubstituted amino bond, a substituted or unsubstituted amide bond, or an ester bond. Or a carbonyl bond. Ar ¹ and Ar ^{2 each} represent a substituted or unsubstituted aryl group.

Among these substituents, the alkyl group means a saturated aliphatic hydrocarbon group such as a methyl group, an ethyl group, a propyl group and a butyl group, which may be unsubstituted or substituted. The cycloalkyl group is, for example, a saturated alicyclic hydrocarbon group such as cyclopropyl, cyclohexyl, norbornyl, and adamantyl, which may be unsubstituted or substituted. The aralkyl group refers to an aromatic hydrocarbon group via an aliphatic hydrocarbon such as a benzyl group and a phenylethyl group, and the aliphatic hydrocarbon and the aromatic hydrocarbon may be unsubstituted or substituted. I don't care. The alkenyl group refers to an unsaturated aliphatic hydrocarbon group containing a double bond such as a vinyl group, an allyl group and a butadienyl group, which may be unsubstituted or substituted. The cycloalkenyl group refers to an unsaturated alicyclic hydrocarbon group containing a double bond such as a cyclopentenyl group, a cyclopentadienyl group, and a cyclohexene group, which may be unsubstituted or substituted. . The alkynyl group means an unsaturated aliphatic hydrocarbon group containing a triple bond such as an acetylenyl group, which may be unsubstituted or substituted. The alkoxy group refers to an aliphatic hydrocarbon group via an ether bond such as a methoxy group, and the aliphatic hydrocarbon group may be unsubstituted or substituted. The alkylthio group is obtained by substituting the oxygen atom of the ether bond of the alkoxy group with a sulfur atom. Further, the aryl ether group refers to an aromatic hydrocarbon group via an ether bond such as a phenoxy group, and the aromatic hydrocarbon group may be unsubstituted or substituted. Also,
The arylthioether group is a group in which an oxygen atom of an ether bond of the arylether group is substituted with a sulfur atom. The aryl group refers to, for example, an aromatic hydrocarbon group such as a phenyl group, a naphthyl group, a biphenyl group, a phenanthryl group, a terphenyl group, and a pyrenyl group, which may be unsubstituted or substituted. Further, the heterocyclic group refers to a cyclic structure group having an atom other than carbon, such as a furanyl group, a thiophenyl group, an oxazolyl group, a pyridyl group, a quinolinyl group, and a carbazolyl group, which may be unsubstituted or substituted. Absent. Halogen refers to fluorine, chlorine, bromine and iodine. Haloalkanes, haloalkenes, and haloalkynes are those in which part or all of the aforementioned alkyl group, alkenyl group, and alkynyl group such as a trifluoromethyl group have been substituted with the aforementioned halogen, and the remaining part is unsubstituted. It may be replaced. Aldehyde, carbonyl, ester, carbamoyl, and amino groups include those substituted with aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, heterocycles, and the like. The cyclic hydrocarbon, aromatic hydrocarbon and heterocyclic ring may be unsubstituted or substituted. The silyl group means a silicon compound group such as a trimethylsilyl group, which may be unsubstituted or substituted. The siloxanyl group means a silicon compound group via an ether bond such as a trimethylsiloxanyl group, which may be unsubstituted or substituted. The fused ring and the aliphatic ring formed between the adjacent substituents include R ¹ and R ² , R ² and R ³ , R ¹ and X ¹ ,
At the site of the ³ and X ² is intended to form a fused ring conjugated or non-conjugated. These condensed rings may contain nitrogen, oxygen and sulfur atoms in the ring structure, or may be condensed with another ring.

When coordinating to a metal, there is no particular limitation on the pyromethene compound alone or a mixed ligand. As the second ligand in the case of a mixed ligand, alkoxy,
It is possible to introduce phenoxy, halogen, alkyl, allyl or other condensed ring hydrocarbons, heterocyclic compounds, or aromatic or heterocyclic compounds linked via an oxygen atom.

The metal which can be coordinated with the ligand of the present invention is not particularly limited, but examples of commonly used elements include boron, beryllium, magnesium, chromium, iron, cobalt, nickel, copper, zinc, platinum And the like.

In consideration of the ease of synthesis and the thermal stability of the compound, it is desirable that the pyromethene compound is a compound represented by the following general formula (2).

[0023]

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Here, R ^{4 to} R ²² may be the same or different, and may be hydrogen, alkyl, cycloalkyl, aralkyl, alkenyl, cycloalkenyl, alkynyl, hydroxyl, mercapto, alkoxy. , Alkylthio, arylether, arylthioether, aryl, heterocyclic, halogen, haloalkane, haloalkene, haloalkyne, cyano, aldehyde, carbonyl, carboxyl, ester, carbamoyl, amino, nitro , A silyl group,
It is selected from a siloxanyl group and an aromatic, aliphatic or heterocyclic condensed ring formed between adjacent substituents. About these substituents, it is the same as that of description of the said General formula (1).

In order to obtain better luminance characteristics, it is desirable that the pyromethene compound is a compound represented by the following general formula (3).

[0026]

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Here, R ^{23 to} R ⁴¹ represent R ^{4 in the} general formula (2).
Selected from the same as the choice to R ^22, it may be the same or different. R ⁴² and R ⁴³ may be the same or different and are selected from halogen, hydrogen, alkyl, aryl, and heterocyclic groups. The substituents mentioned above are the same as those described in the general formula (1).

Further, the availability of materials and the ease of synthesis
Considering the above, R in the above general formula (3) ⁴²And R⁴³Is
It is desirable to be elementary. Pyromethene compound as described above
Specific examples of the compound include the following compounds.

[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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The doping amount is preferably 10% by weight or less, more preferably 2% by weight or less with respect to the host material, since concentration quenching occurs if the amount is too large. As a doping method, it can be formed by a co-evaporation method with a host material, but it may be mixed with the host material in advance and then evaporated at the same time. In addition, the dopant material may be included in the entire host material, partially, or may be included. The dopant material may be stacked, dispersed, or the like. Further, since the pyromethene compound emits light even in a very small amount, it is possible to use a small amount of the pyromethene compound sandwiched between host materials.
In this case, one or more layers may be stacked with the host material. The dopant material to be added to the light-emitting material is not limited to one kind of the pyrromethene compound, and may be used by mixing a plurality of pyromethene compounds, or may be used by mixing one or more kinds of known dopant materials with the pyromethene compound. . Specifically, conventionally known naphthalimide derivatives such as bis (diisopropylphenyl) perylenetetracarboxylic imide, perinone derivatives, rare earth complexes such as Eu complexes having acetylacetone, benzoylacetone and phenanthroline as ligands, 4- (dicyanomethylene) -2-methyl-6- (p-dimethylaminostyryl) -4H-pyran and its analogs, metal phthalocyanine derivatives such as magnesium phthalocyanine and aluminum chlorophthalocyanine, rhodamine compounds, deazaflavin derivatives, oxazine compounds and the like Can coexist, but the present invention is not particularly limited thereto.

The host material is not particularly limited, but a condensed ring derivative such as anthracene or pyrene, a metal chelated oxinoid compound such as tris (8-quinolinolato) aluminum, which has long been known as a luminous body. , Bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, tetraphenylbutadiene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, cyclopentadiene derivatives, oxadiazole derivatives, thiadiazolopyridine derivatives, For the pyrrolopyrrole derivative and the polymer system, a polyphenylenevinylene derivative, a polyparaphenylene derivative, a polythiophene derivative, and the like can be used.

As the electron transporting material in the present invention,
It is necessary to efficiently transport electrons from the cathode between the electrodes to which an electric field is applied, and it is desirable that the electron injection efficiency is high and the injected electrons are transported efficiently. For this purpose, it is required that the material has a high electron affinity, a high electron mobility, a high stability, and a small amount of impurities serving as traps during production and use. Materials satisfying such conditions include quinolinol derivative metal complexes represented by 8-hydroxyquinoline aluminum, tropolone metal complexes, flavonol metal complexes, perylene derivatives, perinone derivatives, naphthalene,
There are coumarin derivatives, oxadiazole derivatives, aldazine derivatives, bisstyryl derivatives, pyrazine derivatives, phenanthroline derivatives, and the like, but are not particularly limited. Although these electron transport materials are used alone,
They may be laminated or mixed with different electron transport materials. The hole blocking layer is a layer for preventing holes from the anode from moving between the electrodes to which an electric field is applied without recombination with electrons from the cathode, and the type of material constituting each layer In some cases, by inserting this layer, the recombination probability of holes and electrons increases, and improvement in luminous efficiency may be expected. Therefore, it is desired that the hole-blocking material has a lower maximum occupied molecular orbital level in terms of energy than the hole-transporting material, and does not easily form an exciplex with the material constituting the adjacent layer. Specific examples thereof include a phenanthroline derivative and a triazole derivative. However, the compound is not particularly limited as long as it is a compound capable of forming a thin film necessary for manufacturing an element and efficiently preventing movement of holes from an anode.

The above hole transport layer, light emitting layer, electron transport layer,
The hole blocking layer may be a single layer or a laminate of two or more materials, or may be a polymer binder such as polyvinyl chloride, polycarbonate, polystyrene, poly (N-vinylcarbazole), polymethyl methacrylate, polybutyl methacrylate, and polyester. , Polysulfone, polyphenylene oxide, polybutadiene, hydrocarbon resin, ketone resin, phenoxy resin, polysulfone, polyamide,
Solvent-soluble resins such as ethyl cellulose, vinyl acetate, ABS resin, polyurethane resin, phenolic resin, xylene resin, petroleum resin, urea resin, melamine resin, unsaturated polyester resin, alkyd resin, epoxy resin,
It is also possible to use the resin dispersed in a curable resin such as a silicone resin.

The method for forming the substance that controls light emission is not particularly limited, such as resistance heating evaporation, electron beam evaporation, sputtering, molecular lamination, and coating. However, resistance heating evaporation and electron beam evaporation are generally used. Preferred in terms of surface. The thickness of the layer depends on the resistance value of the substance that controls light emission and cannot be limited, but is selected from the range of 1 to 1000 nm.

The electric energy mainly refers to a direct current, but it is also possible to use a pulse current or an alternating current.
The current value and the voltage value are not particularly limited. However, in consideration of the power consumption and life of the device, it is necessary to obtain the maximum luminance with the lowest possible energy.

The matrix in the present invention refers to a matrix in which pixels for display are arranged in a lattice, and displays a character or an image by a set of pixels. The shape and size of the pixel depend on the application. For example, a square pixel having a side of 300 μm or less is usually used for displaying images and characters on a personal computer, a monitor, and a television. In the case of a large display such as a display panel, a pixel having a side of mm order is used. . In the case of monochrome display, pixels of the same color may be arranged, but in the case of color display, red, green and blue pixels are displayed side by side. In this case, there are typically a delta type and a stripe type. The matrix may be driven by either a line-sequential driving method or an active matrix. The line-sequential driving has the advantage that the structure is simpler, but the active matrix is sometimes superior when the operating characteristics are taken into consideration.

The segment type in the present invention means that a pattern is formed so as to display predetermined information,
Light is emitted from the determined area. For example, there are a time display and a temperature display on a digital clock or a thermometer, an operation state display of an audio device, an electromagnetic cooker, or the like, and a panel display of an automobile. The matrix display and the segment display may coexist in the same panel.

[0044]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples. The peak wavelength described below is the wavelength of the main peak corresponding to the emission center wavelength, and the half-value width is the spectrum width at half the height of the emission center wavelength in the entire peak.

Example 1 A glass substrate (available from Asahi Glass Co., Ltd., 15 Ω / □, electron beam deposited) on which an ITO transparent conductive film was deposited to a thickness of 150 nm was cut into a size of 30 × 40 mm and etched. The obtained substrate was subjected to ultrasonic cleaning with acetone and "Semicocline 56" for 15 minutes each, and then with ultrapure water. Subsequently, the substrate was subjected to ultrasonic cleaning with isopropyl alcohol for 15 minutes and then immersed in hot methanol for 15 minutes to be dried. This substrate was subjected to UV-ozone treatment for 1 hour immediately before producing the element, and was placed in a vacuum evaporation apparatus, and the degree of vacuum in the apparatus was 5 × 10 ⁻⁵ Pa.
Evacuation was performed until the following. First, 4,4′-bis (N- (m-tolyl) is used as a hole transport material by a resistance heating method.
(-N-phenylamino) biphenyl was deposited to a thickness of 50 nm. Next, tris (5,7-diphenyl-8-quinolinolato) aluminum (III) was used as a host material, and DPT1 shown below was used as a dopant material, and was co-evaporated to a thickness of 15 nm so that the dopant concentration became 1 wt%. The host material was laminated to a thickness of 35 nm. Next, 0.5 nm of lithium and 150 nm of silver were deposited to form a cathode,
A 5 × 5 mm square device was produced. The film thickness referred to here is a value indicated by a crystal oscillation type film thickness monitor. The emission spectrum of this light-emitting element has a peak wavelength of 640 nm, a spectral half width of 30 nm, and a maximum luminance of 3800 cd /.
A red light emission was obtained.

[0046]

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Example 2 A device was produced in exactly the same manner as in Example 1 except that DPT2 shown below was used as a dopant material. The emission spectrum of this light-emitting element has a peak wavelength of 645 nm, a spectral half width of 28 nm, and a maximum luminance of 3500 cd /
A red light emission was obtained.

[0048]

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Comparative Example 1 A sample was produced in exactly the same manner as in Example 1 except that DPT3 shown below was used as a dopant material. The emission spectrum of this light-emitting element has a peak wavelength of 620 nm, a spectral half width of 45 nm, and a maximum luminance of 2700 cd /.
Only red light emission of A was obtained.

[0050]

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[0051]

As described above, by using the pyrromethene compound improved by the present invention as a light emitting material, a red light emitting device having high luminance and high color purity can be obtained.

Claims (8)

[Claims] 1. A device which has a luminescent substance between an anode and a cathode and emits light by electric energy, wherein the device contains a pyromethene compound represented by the general formula (1) or a metal complex thereof. A light emitting element. Embedded image (Here, R ^{1 to} R ³ may be the same or different, and may be hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a mercapto group, an alkoxy group, or an alkylthio group. Group, aryl ether group, aryl thioether group,
Aryl group, heterocyclic group, halogen, haloalkane, haloalkene, haloalkyne, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, It is selected from aromatic, aliphatic and heterocyclic condensed rings formed therebetween. X ¹ and X ²
May be the same or different from each other, and include a single bond, a substituted or unsubstituted alkylene bond, an ether bond, a sulfide bond, a substituted or unsubstituted amino bond, a substituted or unsubstituted amide bond, an ester bond, and a carbonyl bond. Selected from. Ar ¹ and Ar ^{2 each} represent a substituted or unsubstituted aryl group. ) 2. The method according to claim 1, wherein the metal of the metal complex is boron, beryllium, magnesium, chromium, iron, cobalt, nickel,
The light-emitting device according to claim 1, wherein the light-emitting device is at least one selected from copper, zinc, and platinum. 3. The light emitting device according to claim 1, wherein the compound is represented by the following general formula (2). Embedded image (Here, R ^{4 to} R ²² may be the same or different, and each may be hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a mercapto group, an alkoxy group, or an alkylthio group. Group, aryl ether group, aryl thioether group, aryl group, heterocyclic group, halogen, haloalkane,
Haloalkenes, haloalkynes, cyano groups, aldehyde groups, carbonyl groups, carboxyl groups, ester groups, carbamoyl groups, amino groups, nitro groups, silyl groups, siloxanyl groups, aromatic and aliphatic groups formed between adjacent substituents, Alternatively, it is selected from condensed heterocyclic rings. ) 4. The light emitting device according to claim 1, wherein said compound is represented by the following general formula (3). Embedded image (Where R ²³ and R ⁴¹ may be the same or different and each represents hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a mercapto group, an alkoxy group, an alkylthio group). Group, aryl ether group, aryl thioether group, aryl group, heterocyclic group, halogen, haloalkane, haloalkene, haloalkyne, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, an aromatic formed between adjacent substituents, an aliphatic, or .R ⁴² and R ⁴³ are selected from among the fused heterocyclic ring may be the same or different, halogen, hydrogen , Alkyl, aryl, and heterocyclic groups.) 5. The light emitting device according to claim 4, wherein R ⁴² and R ^{43 in} the general formula (3) are fluorine. 6. The light emitting device according to claim 1, wherein said compound is a light emitting material. 7. The light emitting device according to claim 6, wherein said compound is a dopant. 8. The light emitting device according to claim 1, wherein the light emitting device constitutes a display for displaying in a matrix and / or segment system.