JP2002050481A - Light emission element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emission element which has high luminous efficiency, high brightness and excellent color purity. SOLUTION: Concerning the element emitting light by electrical energy in which a luminescence substance exists between a positive electrode and a negative electrode, the element includes an organic phosphor having a 3-substitution benzene skeleton substituted by a hydrocarbon aromatic series condensation ring including three or more ring structures.

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 carried out by Kodak Corporation. W. Tan
g. et al. showed that the organic laminated thin film element emits light with high luminance (Appl. Phys. Lett. 51 (12)
21, p. 913, 1987), and many research institutions are conducting studies. A typical configuration of an organic laminated thin film light emitting device presented by a research group of Kodak Company is a diamine compound having a hole transporting property and a light emitting layer on an ITO glass substrate.
Aluminum hydroxyquinoline and M as 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] The light emitting layer is composed of only a host material,
A host material is doped with a guest material.
The light emitting material is required to have three primary colors, but the research on the green light emitting material has been most advanced so far. At present, intensive studies have been made on red light emitting materials and blue light emitting materials with the aim of improving the characteristics. In particular, a blue light-emitting material that can emit light with high luminance and good color purity is desired.

As the host material, the above-mentioned tris (8-
Metal complexes of quinolinol derivatives including quinolinolato) aluminum, benzoxazole derivatives, stilbene derivatives, benzothiazole derivatives, thiadiazole derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, oxadiazole derivatives, oxadiazole derivative metal complexes And benzazole derivative metal complexes.

As an example of a blue light-emitting host material having relatively good performance, a metal complex obtained by combining a quinolinol derivative with a different ligand (Japanese Patent Laid-Open No. 5-21)
No. 4332) and bisstyrylbenzene derivatives (JP-A-4-117485), but the color purity is not particularly sufficient.

On the other hand, as a dopant material as a guest material, coumarin derivatives such as 7-dimethylamino-4-methylcoumarin, perylene, pyrene and anthracene, which are known to be useful as laser dyes, are known. Fused aromatic ring derivatives, stilbene derivatives, oligophenylene derivatives, furan derivatives, quinolone derivatives, oxazole derivatives, oxadiazole derivatives and the like are known.

[0008]

However, many light-emitting materials (host materials and dopant materials) used in the prior art have low light-emitting efficiency and high power consumption, and have low durability and short element life. Was. In addition, red, green, and blue light emission of three primary colors is required as a full-color display. However, in red and blue light emission, few light emission wavelengths are satisfied, and few light emission peaks have a wide emission peak width and good color purity. In particular, for blue light emission, a material having excellent durability and sufficient luminance and color purity characteristics is required.

An object of the present invention is to solve the problems of the prior art and to provide a light emitting device having high luminous efficiency, high luminance and excellent color purity.

[0010]

SUMMARY OF THE INVENTION The present invention relates to an element which emits light by electric energy in which a light emitting substance is present between a positive electrode and a negative electrode, wherein the element comprises a hydrocarbon aromatic compound having three or more ring structures. A light-emitting device comprising an organic phosphor having a trisubstituted benzene skeleton substituted with a condensed ring.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a positive electrode 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.

In the present invention, the cathode is not particularly limited as long as it can efficiently inject electrons into the organic material layer.
Generally, platinum, gold, silver, copper, iron, tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, calcium, magnesium and the like,
Lithium, sodium, potassium, calcium, magnesium, or an alloy containing these low work function metals is effective in improving the element characteristics by increasing the electron injection efficiency. However, these low work function metals are generally unstable in the air in many cases. For example, a very small amount of lithium or magnesium (1 nm in a vacuum-evaporated film thickness gauge) is added to an organic layer.
Preferred examples include a method of doping the following) and using an electrode having high stability, but the method is not particularly limited since inorganic salts such as lithium fluoride can be used. . Furthermore, for electrode protection, metals such as platinum, gold, 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, It is preferable to laminate a hydrocarbon polymer or the like. 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.

In the present invention, the luminescent substance includes 1) a hole transport layer / a light emitting layer, 2) a hole transport layer / a light emitting layer / an electron transport layer,
3) light emitting layer / electron transport layer, 4) hole transport layer / light emitting layer / hole blocking layer, 5) hole transport layer / light emitting layer / hole blocking layer / electron transport layer, 6) light emitting layer / hole Blocking layer / electron transport layer and
7) Any of the forms in which the above combined substances are mixed in a single layer may be used. That is, as the element configuration, the above 1) to
In addition to the multi-layer structure of 6), only a single layer of a luminescent material 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.

In the present invention, the hole transporting layer is formed of a hole transporting substance alone or a mixture of two or more kinds of substances or a mixture of a hole transporting substance and a polymer binder.
As a hole transporting substance, it is necessary to efficiently transport holes from the positive electrode between electrodes to which an electric field is applied, and it is desirable to have a high hole injection efficiency and to efficiently transport injected holes. . For that purpose, it is required that the ionization potential be small, the hole mobility be large, the stability be further improved, and impurities serving as traps be hardly generated during production and use. The substance satisfying such conditions is not particularly limited,
N, N′-diphenyl-N, N′-di (3-methylphenyl) -4,4′-diphenyl-1,1′-diamine;
N, N'-dinaphthyl-N, N'-diphenyl-4,
Triphenylamines such as 4'-diphenyl-1,1'-diamine, bis (N-allylcarbazole) or bis (N-alkylcarbazole), pyrazoline derivatives, stilbene compounds, hydrazone compounds, oxadiazole derivatives And a phthalocyanine derivative, a heterocyclic compound represented by a porphyrin derivative, in a polymer system, a polycarbonate or a styrene derivative having the monomer in a side chain, polyvinyl carbazole, polysilane and the like are preferable, but a thin film necessary for element production is formed. The compound is not particularly limited as long as it is a compound capable of injecting holes from the positive electrode and further transporting holes.

In the present invention, the light emitting material may be a host material alone or a combination of a host material and a dopant material.
Any of them may be used. 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.

In the present invention, the light emitting material includes an organic phosphor having a trisubstituted benzene skeleton substituted with a hydrocarbon aromatic condensed ring having three or more ring structures. This is a structure in which a condensed hydrocarbon aromatic ring portion has fluorescence and is linked by a benzene skeleton. There is a correlation between the fluorescence spectrum and the conjugation length of the molecule. If the ring structure of the condensed hydrocarbon aromatic ring is small, the conjugation length is short and the fluorescence spectrum has an ultraviolet region. In order for the fluorescence spectrum of the condensed hydrocarbon aromatic ring to be in the visible region, it is necessary to include three or more ring structures.

The condensed hydrocarbon aromatic ring containing three or more ring structures is not particularly limited, but includes paraphenylene derivatives such as terphenyl, quarterphenyl, quinkiphenyl and sexiphenyl, fluorene, biphenylene, and the like. Dihydroanthracene, dibenzosuberan,
Examples include aliphatic fused aromatic ring derivatives such as traxene and triptycene, and fused aromatic ring derivatives such as anthracene, phenanthrene, pyrene, perylene, fluoranthene, chrysene, and coronene. Among them, terphenyl, fluorene, phenanthrene, anthracene, pyrene and perylene are preferred.

The substitution position of the trisubstituted benzene is not particularly limited, but the 1,3- and 5-positions are preferred from the viewpoint of easy synthesis.

The organic phosphor having a trisubstituted benzene skeleton is specifically represented by the following general formula (1).

[0020]

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Here, R ^{1 to} R ³ each represent 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, an 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,
It is selected from nitro, silyl and siloxanyl groups. Ar ^{1 to} Ar ³ each represent an unsubstituted or substituted terphenyl group, an unsubstituted or substituted fluorene group, an unsubstituted or substituted phenanthrene group, an unsubstituted or substituted anthracene group, an unsubstituted or substituted pyrene group, It is selected from among substituted or substituted perylene groups.

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 is, for example, a furyl group, a thienyl group, an oxazolyl group,
It represents a cyclic structural group having an atom other than carbon, such as a pyridyl group, a quinolyl group, and a carbazolyl group, which may be unsubstituted or substituted. 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. Further, a ring structure may be formed between adjacent substituents. The ring structure formed may be unsubstituted or substituted.

Specific examples of the above-mentioned organic phosphor having a trisubstituted benzene skeleton include the following structures.

[0024]

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[0025]

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An organic phosphor having a trisubstituted benzene skeleton may be used as a dopant material, but is preferably used as a host material because of its excellent electron transporting ability.

The host material in the present invention need not be limited to only one organic phosphor having a trisubstituted benzene skeleton.
A plurality of organic phosphors having a trisubstituted benzene skeleton may be used as a mixture, or one or more known host materials may be used as a mixture with an organic phosphor having a trisubstituted benzene skeleton. Examples of the known host material include, but are not particularly limited to, tris (8-quinolinolato) aluminum, a condensed ring derivative such as anthracene, phenanthrene, pyrene, perylene, and chrysene, which has been known as a light emitter before. Metal complexes of quinolinol derivatives, benzoxazole derivatives, stilbene derivatives, benzothiazole derivatives, thiadiazole derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, oxadiazole derivatives, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives Complex, oxadiazole derivative metal complex, benzazole derivative metal complex, coumarin derivative, pyrrolopyridine derivative , Perinone derivatives, thiadiazolopyridine derivatives, the polymer system, polyphenylene vinylene derivatives, polyparaphenylene derivatives, and,
Polythiophene derivatives and the like can be used.

The dopant material to be added to the light emitting material is not particularly limited, but specific examples thereof include phenanthrene, anthracene, pyrene, tetracene, pentacene, perylene, naphthopyrene, dibenzopyrene, and rubrene. Condensed ring derivatives such as benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, benzotriazole derivatives, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, imidazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazoline derivatives, stilbene derivatives, thiophene derivatives , Tetraphenylbutadiene derivatives, cyclopentadiene derivatives, bisstyryl anthracene derivatives, bisstyryl derivatives such as distyrylbenzene derivatives, diaza Ndasen derivatives, furan derivatives,
Benzofuran derivatives, phenylisobenzofuran, dimesitylisobenzofuran, di (2-methylphenyl) isobenzofuran, di (2-trifluoromethylphenyl) isobenzofuran, isobenzofuran derivatives such as phenylisobenzofuran, dibenzofuran derivatives, 7
-Dialkylaminocoumarin derivative, 7-piperidinocoumarin derivative, 7-hydroxycoumarin derivative, 7-methoxycoumarin derivative, 7-acetoxycoumarin derivative, 3-benzthiazolyl coumarin derivative, 3-benzimidazolyl coumarin derivative, 3- Coumarin derivatives such as benzoxazolyl coumarin derivatives, dicyanomethylenepyran derivatives, dicyanomethylenethiopyran derivatives,
Polymethine derivatives, cyanine derivatives, oxobenzanthracene derivatives, xanthene derivatives, rhodamine derivatives, fluorescein derivatives, pyrylium derivatives, carbostyril derivatives, acridine derivatives, bis (styryl)
Benzene derivatives, oxazine derivatives, phenylene oxide derivatives, quinacridone derivatives, quinazoline derivatives,
Pyrrolopyridine derivatives, furopyridine derivatives, 1,2,2
A 5-thiadiazolopyrene derivative, a perinone derivative, a pyrrolopyrrole derivative, a squarylium derivative, a biolanthrone derivative, a phenazine derivative, an acridone derivative, a diazaflavin derivative, and the like can be used as they are, but an isobenzofuran derivative is particularly preferably used.

In the present invention, the electron transporting material needs to efficiently transport electrons from the negative electrode between the electrodes to which an electric field is applied, and has a high electron injection efficiency and a high efficiency of transporting the injected electrons. Is desirable. 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. As a substance satisfying such conditions, 3
An organic phosphor having a trisubstituted benzene skeleton substituted with a hydrocarbon aromatic condensed ring containing one or more ring structures;
Quinolinol derivative metal complex represented by aluminum hydroxyquinoline, tropolone metal complex, flavonol metal complex, perylene derivative, perinone derivative, naphthalene, coumarin derivative, oxadiazole derivative, aldazine derivative, bisstyryl derivative, pyrazine derivative,
There is a phenanthroline derivative, but it is not particularly limited. These electron transporting materials may be used alone or may be laminated or mixed with different electron transporting materials.

The above materials used for the hole transporting layer, the light emitting layer and the electron transporting layer can be used alone to form each layer. As the polymer binder, polyvinyl chloride, polycarbonate, polystyrene, poly (N- Vinyl carbazole), polymethyl methacrylate, polybutyl methacrylate, 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.

In the present invention, the method for forming the luminescent material is not particularly limited, such as resistance heating evaporation, electron beam evaporation, sputtering, molecular lamination, and coating method. It is preferable in terms of characteristics. The thickness of the layer depends on the resistance of the luminescent material and cannot be limited, but is selected from the range of 1 to 1000 nm.

In the present invention, 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 voltage value are not particularly limited,
In consideration of the power consumption and the life of the device, the maximum luminance should be obtained with the lowest possible energy.

In the present invention, a matrix 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. . For monochrome display, pixels of the same color may be arranged, but for color display, red, 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.

In the present invention, the segment type refers to a pattern 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.

In the present invention, the backlight is mainly used for improving the visibility of a display device which does not emit light, and is used for a liquid crystal display device, a clock, an audio device, an automobile panel, a display panel, a sign, and the like. . In particular, as a backlight for a liquid crystal display device, especially a personal computer application in which thinning is an issue, considering that it is difficult to reduce the thickness because the conventional type is made of a fluorescent lamp or a light guide plate, the present invention The backlight is thin and lightweight.

[0036]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

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 150 nm was cut into a size of 30 × 40 mm and etched. The obtained substrate was subjected to ultrasonic cleaning with acetone and "Semicocrine 56" (manufactured by Furuuchi Chemical Co., Ltd.) for 15 minutes, and then with ultrapure water. Subsequently, the substrate was subjected to ultrasonic cleaning with isopropyl alcohol for 15 minutes, immersed in hot methanol for 15 minutes, and dried. Immediately before this element is fabricated,
V-ozone treatment was performed, the apparatus was set in a vacuum evaporation apparatus, and the apparatus was evacuated until the degree of vacuum in the apparatus became 5 × 10 ⁻⁵ Pa or less. By the resistance heating method, 4,4'-
Bis (N- (m-tolyl) -N-phenylamino) biphenyl was deposited to a thickness of 50 nm. Next, as a light emitting material,
15 n of 3,5-tris (p-terphenyl) benzene
m. Next, 2,9 as an electron transport material
-Dimethyl-4,7-diphenyl-1,10-phenanthroline was laminated to a thickness of 35 nm. Next, after doping the organic layer with lithium to a thickness of 0.5 nm, aluminum was vapor-deposited to a thickness of 200 nm to form a cathode, thereby producing a 5 × 5 mm square device. The film thickness referred to here is a value indicated by a crystal oscillation type film thickness monitor. Luminance meter, fluorescence spectrophotometer,
The luminance, emission spectrum and CIE chromaticity were measured using a colorimeter. From this light emitting element, an emission wavelength of 405n
m, good blue light emission with CIE chromaticity (0.20, 0.20) was obtained. In addition, the above light emitting element was set to 1 mA in a vacuum cell.
Pulse drive (duty ratio 1/60, current value 6 at pulse)
0 mA), high-brightness blue light emission with good color purity was confirmed.

Example 2 A light emitting device was manufactured in exactly the same manner as in Example 1 except that 1,3,5-tris (2-fluorenyl) benzene was used as a light emitting material. The emission wavelength of this light emitting element is 429.
Good blue light emission of nm and CIE chromaticity (0.21, 0.25) was obtained.

Example 3 A light emitting device was manufactured in exactly the same manner as in Example 1 except that 1,3,5-tris (2-phenanthrenyl) benzene was used as a light emitting material. The light emitting wavelength 51
Good blue light emission of 7 nm and CIE chromaticity (0.22, 0.38) was obtained.

Example 4 The procedure was the same as in Example 1 up to the deposition of the hole transport material. Next, using 1,3,5-tris (2-fluorenyl) benzene used in Example 2 as a host material and di (2-methylphenyl) isobenzofuran (fluorescence peak wavelength is 468 nm) as a dopant material, Is 1w
Co-evaporation was performed to a thickness of 15 nm so as to be t%. Next, a light-emitting element was manufactured in the same manner as in Example 1 from the evaporation of the electron transporting material. From this light-emitting element, an emission spectrum similar to the fluorescence spectrum of the dopant material was observed, and high-luminance blue light emission with good color purity was obtained.

Example 5 A glass substrate on which an ITO transparent conductive film was deposited to a thickness of 150 nm (product of Asahi Glass Co., Ltd., 15 Ω / □, electron beam deposited) was cut into a size of 30 × 40 mm, and a 300 μm pitch (remaining width of 270 μm) was obtained by photolithography. ) X 32 stripes were patterned. One side of the long side of the ITO stripe is used to facilitate electrical connection with the outside.
It is expanded to a pitch of 27 mm (opening width 800 μm). 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, immersed in hot methanol for 15 minutes, and dried.
This substrate was subjected to UV-ozone treatment for 1 hour immediately before the device was manufactured, and was placed in a vacuum evaporation apparatus.
Evacuation was performed until the pressure became × 10 ⁻⁴ Pa or less. By the resistance heating method, first, 4,4′-bis (N-
(M-tolyl) -N-phenylamino) biphenyl
0 nm was deposited, and 1,3,5-tris (2-fluorenyl) benzene used in Example 2 was deposited to a thickness of 15 nm. Next, as an electron transporting material, 2,9-dimethyl-
4,7-diphenyl-1,10-phenanthroline is converted to 3
It was laminated to a thickness of 5 nm. The film thickness referred to here is a value indicated by a crystal oscillation type film thickness monitor. Next, 16 pieces of 250 μm thick Kovar plate having a thickness of 50 μm were wet-etched.
Opening (corresponding to the remaining width of 50 μm and 300 μm pitch)
The mask provided with was replaced in a vacuum so as to be orthogonal to the ITO stripe, and was fixed with a magnet from the back surface so that the mask and the ITO substrate were in close contact with each other. Then add lithium to 0.
After doping the 5 nm organic layer, aluminum
A 32 × 16 dot matrix element was produced by vapor deposition of 0 nm. When this device was driven in a matrix, characters could be displayed without crosstalk.

[0042]

According to the present invention, it is possible to provide a light emitting device having high luminous efficiency and excellent color purity. It is particularly effective for blue light emission.

Claims (5)

[Claims] 1. An element which emits light by electric energy, in which a light emitting substance is present between a positive electrode and a negative electrode, wherein the element is substituted with a hydrocarbon aromatic condensed ring containing three or more ring structures. A light-emitting device comprising an organic phosphor having a substituted benzene skeleton. 2. An organic phosphor having a trisubstituted benzene skeleton is represented by the following general formula (1).
The light-emitting element according to any one of the preceding claims. Embedded image (Where R ^{1 to} R ³ are each hydrogen, alkyl, cycloalkyl, aralkyl, alkenyl, cycloalkenyl, alkynyl, hydroxyl, mercapto, alkoxy, alkylthio, arylether, arylthioether Group, aryl group, heterocyclic group, halogen, haloalkane, haloalkene, haloalkyne, cyano group, aldehyde group, carbonyl group, carboxyl group,
It is selected from ester groups, carbamoyl groups, amino groups, nitro groups, silyl groups, and siloxanyl groups. Ar ^{1 to} A
r ³ is an unsubstituted or substituted terphenyl group,
It is selected from an unsubstituted or substituted fluorene group, an unsubstituted or substituted phenanthrene group, an unsubstituted or substituted anthracene group, an unsubstituted or substituted pyrene group, and an unsubstituted or substituted perylene group. ) 3. The light emitting device according to claim 1, wherein said organic phosphor is a light emitting material. 4. The light emitting device according to claim 1, wherein said organic phosphor is an electron transporting material. 5. The light emitting device according to claim 1, wherein the light emitting device is a display for displaying by a matrix and / or a segment system.