JP2001250689A - Light emission element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light emission element which has high light emission efficiency and is excellent in color purity with high luminosity. SOLUTION: On the light emission element which emits light by electric energy while light emission substance exists between an anode and a negative pole, the element contains the compound expressed with a formula (1). In the formula, R1-R5 may be the same or not, and they are chosen from the ring structure formed between those as below; combination, hydrogen, alkyl group, cyclo-alkyl group, aralkyl group, alkenyl group, cyclo-alkenyl group, alkoxy group, alkyl-thio group, allyl-ether group, allyl-thio-ether group, allyl group, heterocyclic group, hydroxyl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, cyril group, siloxanyl group, and a contiguity substitution group. Z is chosen from either oxygen or nitrogen of substitution or non-substitution.

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 a host material alone or a host material doped with a guest material. Among the three primary color light-emitting materials, research on a green light-emitting material is the most advanced, and at present, earnest research is being conducted on red light-emitting materials and blue light-emitting materials with the aim of improving characteristics. Particularly, in blue light emission, a material having excellent durability and sufficient luminance and color purity characteristics is desired.

Examples of the host material include metal complexes of quinolinol derivatives such as tris (8-quinolinolato) aluminum, metal complexes of benzoquinolinol, benzoxazole derivatives, benzothiazole derivatives, thiadiazole derivatives, and thiophene derivatives.

As a host material for emitting blue light, a metal complex obtained by combining a quinolinol derivative with a different ligand,
Examples include benzimidazole derivatives, and bisstyrylbenzene derivatives (Japanese Patent Application Laid-Open No. 4-117485) have relatively good characteristics, but the color purity is not particularly sufficient. Further, as a compound having a structure similar to the present invention, there is JP-A-8-104867, which has yellow-green emission because it has an aromatic ring having an amide bond,
It differs from the concept of the present invention, which is useful as a material for emitting blue light and for transporting electrons. Further, Japanese Unexamined Patent Application Publication No.
-298186 and JP-A-11-149982
In Japanese Patent Application Laid-Open Publication No. H10-209, there is a structure in which the position of the oxygen atom is different from the structure of the present invention, but these emit red and blue-green light, respectively, and blue light as in the present invention has not been obtained.

On the other hand, as a dopant material as a guest material, a fluorescent coumarin dye such as 7-dimethylamino-4-methylcoumarin, a dicyanomethylenepyran dye, which is known to be useful as a laser dye, Dicyanomethylenethiopyran dye, polymethine dye, cyanine dye, oxobenzanthracene dye, xanthene dye, rhodamine dye, fluorescein dye,
Pyrylium dye, carbostyril dye, perylene dye,
Acridine dye, bis (styryl) benzene dye, pyrene dye, oxazine dye, phenylene oxide dye,
Perylene, tetracene, pentacene, quinacridone compound, pyrrolopyridine compound, furopyridine compound, 1,
2,5-thiadiazolopyrene derivatives, perinone derivatives,
Pyrrolopyrrole compounds, squarylium compounds, biolanthrone compounds, phenazine derivatives, acridone compounds, diazaflavin derivatives and the like are known.

[0008]

However, the luminescent materials (host materials and dopant materials) used in the prior art include those having low luminous efficiency and high power consumption, and those having low durability of the compound and short element life. There were many. 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]

According to the present invention, there is provided an element which has a luminescent substance between an anode and a cathode and emits light by electric energy, wherein the element contains a compound represented by the following general formula (1). It is a light emitting element characterized by the following.

[0011]

Embedded image

(Wherein R _{1 to} R ₅ may be the same or different and each represents a bond, hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkoxy group, an alkylthio group, an aryl ether Group, arylthioether group, aryl group, heterocyclic group, hydroxyl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, adjacent substitution Selected from ring structures formed between the group and Z. Z is selected from oxygen, and substituted or unsubstituted nitrogen.)

[0013]

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 material of the present invention is defined as 1) a hole transport layer /
Light-emitting layer, 2) hole-transport layer / light-emitting layer / electron-transport layer, 3) light-emitting layer / electron-transport layer, and 4) a form in which a combination of the above substances is mixed into one layer; Layer / hole blocking layer / electron transporting layer; 6) light emitting layer / hole blocking layer / electron transporting layer; and 7) any combination of one or more of the combined substances. That is, as the element configuration,
In addition to the multi-layer structure of the above 1) to 6), as in the case of 7), a single layer of a light-emitting material alone or a layer containing a light-emitting material and a hole transport material or an electron transport material may be provided. Furthermore, the luminescent substance in the present invention corresponds to any of those that emit light by themselves and those that assist the light emission, and compounds that participate in light emission,
It refers to a layer or the like.

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. Triphenylamines such as TPD, m-MTDATA, α-NPD, bis (N-allylcarbazole)
Or bis (N-alkylcarbazole) s, pyrazoline derivatives, stilbene compounds, hydrazone compounds,
Oxadiazole derivatives, phthalocyanine derivatives, heterocyclic compounds typified by porphyrin derivatives, and in polymer systems, polycarbonates and styrene derivatives having the above monomers in side chains, polyvinylcarbazole, polysilane, etc. are preferred, but thin films required for device fabrication are preferred. Is not particularly limited as long as it is a compound capable of injecting holes from the anode and transporting 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.

The luminescent material of the present invention contains a compound represented by the following general formula (1).

[0019]

Embedded image

Here, R _{1 to} R ₅ may be the same or different and each represents a bond, hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkoxy group, an alkylthio group, an aryl ether group. , Arylthioether group, aryl group, heterocyclic group,
Hydroxyl, halogen, cyano, aldehyde,
It is selected from a carbonyl group, a carboxyl group, an ester group, a carbamoyl group, an amino group, a nitro group, a silyl group, a siloxanyl group, and a ring structure formed between adjacent substituents. Z is selected from oxygen and substituted or unsubstituted nitrogen.

In the description of these substituents, a bond means that the substituent is linked to a plurality of skeletons represented by the general formula (1) at that position. In this case, a plurality of general formulas (1)
May be directly linked, or may be linked via a certain bonding unit. The alkyl group refers to 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 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. Further, 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 structural group having an atom other than carbon, such as a furyl group, a thienyl group, an oxazolyl group, a pyridyl group, a quinolyl 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 some or all of the aforementioned alkyl, alkenyl, and alkynyl groups, such as trifluoromethyl, have been substituted with the aforementioned halogens, and the rest are unsubstituted. It may be replaced. Aldehyde groups, carbonyl groups, ester groups, carbamoyl groups, 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 refers to a silicon compound group via an ether bond such as a trimethylsiloxanyl group, which may be unsubstituted or substituted. The ring structure formed between adjacent substituents may be unsubstituted or substituted.

The luminescent material of the present invention may be contained in the form of a metal complex having a compound represented by the following general formulas (2) and (3) as a ligand.

[0023]

Embedded image

Here, R _{6 to} R ₉ may be the same or different, and include hydrogen, an alkyl group, a cycloalkyl group,
Aralkyl, alkenyl, cycloalkenyl, alkoxy, alkylthio, arylether, arylthioether, aryl, heterocyclic, halogen, cyano, aldehyde, carbonyl, carboxyl, ester, carbamoyl , An amino group, a nitro group, a silyl group, a siloxanyl group, and a ring structure formed between adjacent substituents. Z is selected from oxygen and substituted or unsubstituted nitrogen.

[0025]

Embedded image

Here, R _{10 to} R ₁₇ may be the same or different, and may be hydrogen, alkyl, cycloalkyl, aralkyl, alkenyl, cycloalkenyl, alkoxy, alkylthio, arylether, arylether. Thioether group, aryl group, heterocyclic group,
Halogen, haloalkane, haloalkene, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group,
It is selected from a siloxanyl group and a ring structure formed between adjacent substituents. Z is selected from oxygen and substituted or unsubstituted nitrogen. These substituents are the same as those described above.

The metal forming the metal complex is not particularly limited, but includes sodium, lithium, boron, beryllium, magnesium, aluminum, gallium, chromium, iron, cobalt, nickel, copper, zinc, gallium, indium, Preferable examples include thallium, platinum and the like. These metals are represented by the general formula (2),
A complex is formed between the hydroxyl group contained in the general formula (3) and the nitrogen atom. However, a monovalent metal salt such as sodium and lithium may be present in a form such as a sodium salt and a lithium salt in which the above-mentioned hydroxyl group is replaced by hydrogen.

Further, a compound having a plurality of the above general formulas (1) is preferable because thermal stability is obtained, and a compound represented by the following general formula (4) is preferable because it is easy to modify a molecule into a branched shape. Are more preferred.

[0029]

Embedded image

Here, R _{18 to} R ₂₁ may be the same or different, and may be hydrogen, alkyl, cycloalkyl, aralkyl, alkenyl, cycloalkenyl, alkoxy, alkylthio, arylether, arylether. Thioether group, aryl group, heterocyclic group,
Halogen, haloalkane, haloalkene, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group,
It is selected from a siloxanyl group and a ring structure formed between adjacent substituents. Z is selected from oxygen and substituted or unsubstituted nitrogen. n is an integer of 2 or more;
X is a bonding unit for bonding a plurality of skeletons to each other conjugated or non-conjugatedly.

In the description of these substituents, R _{18 to} R ₂₁
Is the same as described above. X, which is a bonding unit, is a single bond, a double bond, an alkyl, a cycloalkyl, an aryl, a heterocyclic ring, an ether or a thioether, which may be unsubstituted or substituted, and may be used alone or in combination. It doesn't matter.

Further, in order to obtain high luminance emission using the compound of the present invention, it is preferable to use a compound having a high carrier transporting ability. Therefore, as the compound having a plurality of the mother skeletons, a compound containing an aromatic ring in a bonding unit is more preferable. The aromatic ring as used herein means a substituted or unsubstituted aromatic hydrocarbon or aromatic heterocyclic ring, and these may be used alone or in combination.

Specific examples of the above compounds include the following structures.

[0034]

Embedded image

[0035]

Embedded image

The compound of the present invention may be used as a dopant material or a host material.

The host material of the light-emitting material is not limited to one kind of the compound having the skeleton represented by the general formula (1). A plurality of such compounds may be used as a mixture, or one or more kinds of known host materials may be used. May be used as a mixture. The known host material is not particularly limited, but condensed ring derivatives such as phenanthrene, pyrene, perylene, and chrysene, and quinolinol derivatives such as tris (8-quinolinolato) aluminum, which have been known as luminous bodies before. Metal complexes, benzazole derivatives and their metal complexes, metal complexes of quinolinol derivatives and different ligands, oxadiazole derivatives and their metal complexes, thiadiazole derivatives, stilbene derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene Derivatives, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, coumarin derivatives, pyrrolopyridine derivatives,
Pyrrolopyrrole derivatives, perinone derivatives, thiadiazolopyridine derivatives, and polymer systems include polyphenylenevinylene derivatives, polyparaphenylene derivatives, and polythiophene derivatives.

The dopant material to be added to the light emitting material is not particularly limited, but specific examples other than the compound having an imidazopyridine skeleton include conventionally known anthracene, pyrene, perylene, and naphthopyrene. Condensed ring derivatives such as dibenzopyrene, azole derivatives and their metal complexes, triazole derivatives and their metal complexes, benzazole derivatives and their metal complexes, benzotriazole derivatives and their metal complexes, oxadiazole derivatives and their metal complexes, pyrazoline derivatives , Stilbene derivatives, thiophene derivatives, tetraphenylbutadiene derivatives, cyclopentadiene derivatives, bisstyryl derivatives such as bisstyrylanthracene derivatives and distyrylbenzene derivatives, diazaindacene derivatives, furan derivatives , Benzofuran derivatives, isobenzofuran derivatives, dibenzofuran derivatives, coumarin derivatives, xanthene derivatives, carbostyril derivatives, acridine derivatives, phenylene oxide derivatives, quinacridone derivatives, pyrrolopyridine derivatives, furopyridine derivatives, phenazine derivatives and the like can be used as they are, especially isobenzofuran. Derivatives are preferably 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. Since the compound in the present invention also has an electron transporting ability, it can be used as an electron transporting material. 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, polyamide, ethyl cellulose, vinyl acetate, ABS resin, polyurethane resin, and other solvent-soluble resins. It can also be used by dispersing it in a curable resin such as a phenol resin, a xylene resin, a petroleum resin, a urea resin, a melamine resin, an unsaturated polyester resin, an alkyd resin, an epoxy resin, or a silicone resin.

The method for forming the luminescent material in the present invention is not particularly limited, such as resistance heating evaporation, electron beam evaporation, sputtering, molecular lamination, and coating. Is preferred 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 10 to 1000 nm.

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

It is preferable that the light emitting device of the present invention constitutes a display for displaying by a matrix or segment system or a combination of both.
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, for the display of images and characters on personal computers, monitors, televisions, and the like, generally square pixels with a side of 300 μm or less are used, and in the case of a large display such as a display panel, pixels with a side on the order of mm are used. Become. 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. Note that the light-emitting element of the present invention can emit red, green, and blue light, so that multi-color or full-color display can be performed by using the display method. The matrix may be driven by either a line-sequential driving method or an active matrix. Line-sequential drive has the advantage of a simpler structure,
In consideration of the operation characteristics, the active matrix is sometimes superior, so it is necessary to use the active matrix properly depending on the application.

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

The light emitting device of the present invention is also preferably used as a backlight. The backlight is mainly used for improving the visibility of a display device that 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 for the backlight for liquid crystal display devices, particularly for personal computer applications where thinning is an issue, the present invention is considered to be difficult because the conventional type is made of a fluorescent lamp or a light guide plate, and it is difficult to make it thin. The backlight using the light emitting element in the above is characterized by being thin and lightweight.

[0046]

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 (15 Ω / □, manufactured by Asahi Glass Co., Ltd., electron beam deposited) on which an ITO transparent conductive film was deposited to a thickness of 150 nm was cut into 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, immersed in hot methanol for 15 minutes, and 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 (TPD)
m was deposited. Next, as a light emitting material, EM shown below
1 was laminated to a thickness of 15 nm. Next, 2,9-dimethyl-4,7-diphenyl-1,10 is used as an electron transport material.
-Phenanthroline was laminated to a thickness of 35 nm, and was subsequently slightly doped with metallic lithium (converted to a film thickness of 0.5
nm). Finally, silver was deposited to a thickness of 150 nm to form a cathode.
A device having a size of 5 mm square was manufactured. The film thickness referred to here is a value displayed on a crystal oscillation type film thickness monitor corrected by a value measured by a surface roughness meter. This light-emitting element emitted clear blue light.

[0048]

Embedded image

Comparative Example 1 A light-emitting device produced in exactly the same manner as in Example 1 except that the following compounds were used as a light-emitting material, only yellow-green light emission was obtained.

[0050]

Embedded image

Example 2 A light emitting device was manufactured in exactly the same manner as in Example 1 except that EM2 shown below was used as a host material. From this light emitting device, clear blue light emission was obtained.

[0052]

Embedded image

Example 3 A light emitting device was manufactured in exactly the same manner as in Example 1 except that EM3 shown below was used as a host material. From this light emitting device, clear blue light emission was obtained.

[0054]

Embedded image

Example 4 A light emitting device was manufactured in exactly the same manner as in Example 1 except that EM4 shown below was used as a host material. From this light emitting device, clear blue light emission was obtained.

[0056]

Embedded image

Example 5 Tris (8-quinolinolato) aluminum (III) (Alq3) was laminated to a thickness of 35 nm as a light emitting material, and then 15 n of EM4 in Example 4 was used as an electron transporting material.
A light emitting device was produced in exactly the same manner as in Example 1 except that the light emitting device was laminated to a thickness of m. Green light emission based on Alq3 was obtained from this light emitting device. The compound of the present invention also effectively functioned as an electron transport layer.

Example 6 A glass substrate (15 Ω / □, manufactured by Asahi Glass Co., Ltd., electron beam deposited) on which an ITO transparent conductive film was deposited to a thickness of 150 nm was cut into 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. First, 50 nm of TPD was deposited as a hole transport layer by a resistance heating method, and EM4 used in Example 4 was 15 nm as a light emitting layer.
And, as an electron transport layer, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline was deposited to a thickness of 35 nm. 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, after doping a small amount of metallic lithium (0.5 nm in terms of film thickness), aluminum was deposited to a thickness of 150 nm to produce a 32 × 16 dot matrix element. When this device was driven in a matrix, characters could be displayed without crosstalk.

[0059]

The light emitting device of the present invention is particularly effective for emitting blue light.

Claims (9)

[Claims] 1. A light-emitting element in which a light-emitting substance is present between an anode and a cathode and emits light by electric energy, wherein the element contains a compound represented by the general formula (1). Embedded image (Where R _{1 to} R ₅ may be the same or different, and each represents a bond, hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkoxy group, an alkylthio group, an aryl ether group, or an aryl group. Thioether group, aryl group, heterocyclic group, hydroxyl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, with adjacent substituents Selected from among ring structures formed therebetween, wherein Z is selected from oxygen, substituted or unsubstituted nitrogen.) 2. The light emitting device according to claim 1, wherein said compound is a compound represented by the general formula (2) or a metal complex thereof. Embedded image (Where R _{6 to} R ₉ may be the same or different, and each represents a hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkoxy group, an alkylthio group, an arylether group, an arylthioether group. , Aryl group, heterocyclic group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group,
It is selected from ester groups, carbamoyl groups, amino groups, nitro groups, silyl groups, siloxanyl groups, and ring structures formed between adjacent substituents. Z is selected from oxygen and substituted or unsubstituted nitrogen. ) 3. The light emitting device according to claim 1, wherein said compound is a compound represented by the general formula (3) or a metal complex thereof. Embedded image (Where R _{10 to} R ₁₇ may be the same or different, and each represents a hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkoxy group, an alkylthio group, an arylether group, an arylthioether group. , Aryl group, heterocyclic group, halogen, haloalkane, haloalkene, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, between adjacent substituents Wherein Z is selected from oxygen, substituted and unsubstituted nitrogen.) 4. A device in which a luminescent substance is present between an anode and a cathode and emits light by electric energy, wherein the device contains a compound having a plurality of skeletons represented by the general formula (1). Item 2. A light emitting device according to item 1. 5. The light emitting device according to claim 4, wherein said compound is represented by the general formula (4). Embedded image (Where R _{18 to} R ₂₁ may be the same or different, and each represents a hydrogen, an alkyl group, a cycloalkyl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkoxy group, an alkylthio group, an arylether group, an arylthioether group. , Aryl group, heterocyclic group, halogen, haloalkane, haloalkene, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, between adjacent substituents Z is selected from oxygen, substituted or unsubstituted nitrogen, n is an integer of 2 or more, and X is conjugated or non-conjugated to a plurality of skeletons. Is a bonding unit bonded to each other.) 6. The light emitting device according to claim 4, wherein the bonding unit represented by X in the general formula (4) contains an aromatic ring. 7. The light emitting device according to claim 1, wherein said compound is a light emitting material. 8. The light emitting device according to claim 1, wherein said compound is an electron transporting material. 9. The light emitting device according to claim 7, wherein the light emitting device constitutes a display for displaying in a matrix and / or segment system.