JP2009267430A - Organic electroluminescent element, and display device having the same - Google Patents

Organic electroluminescent element, and display device having the same Download PDF

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JP2009267430A
JP2009267430A JP2009146249A JP2009146249A JP2009267430A JP 2009267430 A JP2009267430 A JP 2009267430A JP 2009146249 A JP2009146249 A JP 2009146249A JP 2009146249 A JP2009146249 A JP 2009146249A JP 2009267430 A JP2009267430 A JP 2009267430A
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organic el
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JP5104816B2 (en
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Mitsuhiro Fukuda
Motoi Kinoshita
Hiroshi Kita
Tomohiro Oshiyama
Yoshiyuki Suzuri
Noriko Ueda
弘志 北
智寛 押山
基 木下
則子 植田
善幸 硯里
光弘 福田
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Konica Minolta Holdings Inc
コニカミノルタホールディングス株式会社
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Abstract

An object of the present invention is to provide an organic electroluminescence element exhibiting high light emission luminance and a long half-life, and a display device using the same.
An organic electroluminescence device comprising a compound represented by the following general formula (3).
General formula (3)
X 2 - (A 2) m
Wherein, -A 2 is represented by the following general formula (4) may be the same or different.
[Chemical 1]

[Selection figure] None

Description

  The present invention relates to an organic electroluminescence element and a display device using the same.

  Conventionally, there is an electroluminescence display (ELD) as a light-emitting electronic display device. Examples of the constituent elements of ELD include inorganic electroluminescent elements and organic electroluminescent elements (hereinafter also abbreviated as organic EL elements). Inorganic electroluminescent elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements.

  On the other hand, an organic electroluminescence device has a structure in which a light emitting layer containing a light emitting compound is sandwiched between a cathode and an anode, and excitons (exciton) are injected by injecting electrons and holes into the light emitting layer and recombining them. ), Which emits light by utilizing the emission of light (fluorescence / phosphorescence) when the exciton is deactivated, and can emit light at a voltage of several volts to several tens of volts. Since it is a type, it has a wide viewing angle, high visibility, and since it is a thin-film type completely solid element, it has attracted attention from the viewpoint of space saving, portability, and the like.

  For the development of organic EL elements for practical use in the future, organic EL elements that emit light with high power and efficiency with low power consumption are desired. For example, stilbene derivatives, distyrylarylene derivatives, or tristyryl A technique for doping an arylene derivative with a small amount of a phosphor to improve emission luminance and extend the lifetime of the device (see, for example, Patent Document 1), and 8-hydroxyquinoline aluminum complex as a host compound. A device having an organic light-emitting layer doped with a phosphor (for example, see Patent Document 2), a device having an organic light-emitting layer doped with a quinacridone-based dye as an 8-hydroxyquinoline aluminum complex as a host compound (for example, Patent Document 3) is known.

In the technique disclosed in the above document, when light emission from an excited singlet is used, the generation ratio of singlet excitons and triplet excitons is 1: 3. Since the light extraction efficiency is about 20%, the limit of the external extraction quantum efficiency (η ext ) is set to 5%.

  On the other hand, since the University of Princeton has reported on organic EL devices that use phosphorescence from excited triplets (see, for example, Non-Patent Document 1), research on materials that exhibit phosphorescence at room temperature has become active. (For example, refer nonpatent literature 2 and patent literature 4.).

  When excited triplets are used, the upper limit of internal quantum efficiency is 100%, so in principle the luminous efficiency is four times that of excited singlets, and the performance is almost the same as that of cold cathode tubes. It can be applied to and attracts attention.

  On the other hand, it has been proposed to provide a hole blocking layer that restricts the movement of holes from the light emitting layer between the light emitting layer and the cathode in order to improve the light emission luminance and light emission lifetime of the organic EL element. By efficiently accumulating holes in the light emitting layer by this hole blocking layer, it is possible to improve the recombination probability with electrons and achieve high efficiency of light emission. It has been reported that use of a phenanthroline derivative or a triazole derivative alone as a hole blocking material is effective (see Patent Documents 5 and 6). In addition, a long-life organic EL element is realized by using a specific aluminum complex for the hole blocking layer (see Patent Document 7).

  As described above, with the introduction of the hole blocking layer, in the organic EL element using the phosphorescent compound, in green, the internal quantum efficiency is almost 100% and the lifetime is 20,000 hours (see Non-Patent Document 3). There is still room for improvement in terms of luminance.

  In addition, when a blue to blue-green phosphorescent compound is used as a dopant, there is an example in which a carbazole derivative such as CBP is used as a host compound, but the external extraction quantum efficiency is 6%, which is an insufficient result. (See Non-Patent Document 4), there remains room for improvement. For blue, light emission from fluorescent compounds is used, but a linking group is introduced into the biaryl moiety in the middle of the carbazole derivative molecule to produce an organic EL device with excellent blue color purity and long life. (For example, see Patent Document 8). Furthermore, in addition to the above compound, when a specific pentacoordinate metal complex is used for the hole blocking layer and a phosphorescent compound is used as a dopant, a longer lifetime is achieved (for example, Patent Documents). 9).

  However, even when such a linking group is introduced, the carbazole derivatives described in the above-mentioned patents have not yet reached luminous efficiency and heat resistance that can withstand practical use. In organic EL elements for practical use in the future, development of organic EL elements that emit light efficiently and with high luminance with low power consumption is desired.

Japanese Patent No. 3093796 Japanese Unexamined Patent Publication No. 63-264692 JP-A-3-255190 US Pat. No. 6,097,147 JP-A-8-109373 JP-A-10-233284 JP 2001-284056 A JP 2000-21572 A Japanese Patent Laid-Open No. 2002-8860

M.M. A. Baldo et al. , Nature, 395, 151-154 (1998) M.M. A. Baldo et al. , Nature, 403, 17, 750-753 (2000) 62nd Japan Society of Applied Physics Academic Lecture Proceedings 12-a-M7, Pioneer Technical Information Magazine, Vol. 11, No. 1 62nd Japan Society of Applied Physics Academic Lecture Proceedings 12-a-M8

  An object of the present invention is to provide an organic electroluminescence element that exhibits high emission luminance and has a long half-life, and a display device using the same.

  The above object of the present invention is achieved by the following configurations.

  1. The organic electroluminescent element characterized by containing the compound represented by following General formula (3).

General formula (3)
X 2 - (A 2) m
Wherein, -A 2 is represented by the following general formula (4) may be the same or different.

In the formula, Ar 2 is a divalent aromatic hydrocarbon ring group or an aromatic heterocyclic group. R 3 and R 4 each represent a hydrogen atom, an alkyl group or an aryl group. m represents an integer of 2 to 4, and nc and nd each represents an integer of 0 to 4. X 2 is any one selected from linking groups represented by the following general formulas (l) to (o).

In the formula, R 101 to R 110 each represent a hydrogen atom, an alkyl group, or an aryl group, and are not connected to each other to form a ring. At least one of R 101 to R 110 is an alkyl group or an aryl group. R 111 to R 118 each represent a hydrogen atom, an alkyl group, or an aryl group. A 1 to A 4 each represent either —C (R k1 ) or —N═, and at least one of them is —N═. R k1 represents a hydrogen atom or an alkyl group. A 5 to A 8 each represent —C (R k2 ) or —N═, and X b represents —NR k3 or> Si (R k4 ) (R k5 ). R k2 to R k5 each represent a hydrogen atom, an alkyl group, or an aryl group. In addition, * represents a connection part. ]
2. 2. The organic electroluminescence device according to 1 above, wherein a hole blocking layer is provided between the light emitting layer and the cathode.

  3. 3. The organic electroluminescence device according to 2 above, wherein the hole blocking layer is composed of at least one compound of a styryl compound, a triazole derivative, a phenanthroline derivative, an oxadiazole derivative, or a boron derivative.

  4). 3. The organic electroluminescence as described in 2 above, wherein the hole blocking layer comprises at least one compound represented by the following general formula (5), (6), (7) or (8). element.

[Wherein, R a1 to R a3 , R b1 to R b4 , R c1 , and R c2 each represents an alkyl group, an aryl group, or a heterocyclic group, and A ra to A rc each represents an aryl group or a complex Represents a cyclic group. ]
5. The light emitting layer contains the compound represented by the said General formula (3), The organic electroluminescent element of any one of said 1-4 characterized by the above-mentioned.

  6). 6. The organic electroluminescence device as described in any one of 1 to 5 above, which contains a phosphorescent compound.

  7. 7. The organic electroluminescence device as described in 6 above, wherein the phosphorescent compound is osmium, iridium, or a platinum complex compound.

  8). 8. A display device comprising the organic electroluminescence element according to any one of 1 to 7 above.

  According to the present invention, it was possible to provide an organic electroluminescence element exhibiting high light emission luminance and having a long half-life and a display device using the same.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. 4 is a schematic diagram of a display unit A. FIG. It is a schematic diagram of a pixel. It is a schematic diagram of the display apparatus by a passive matrix system.

  Hereinafter, the present invention will be described in detail.

  As a result of intensive investigations, the present inventors have used at least one compound represented by the general formula (3), thereby exhibiting high emission luminance and a long half-life, and the organic EL element. It has been found that a display device having the above can be provided. In addition, it was found that a highly efficient full-color image display device can be obtained by combining the above compounds.

  The organic electroluminescence device of the present invention is characterized in that at least one of the compounds represented by the general formula (3) is contained in at least one layer constituting the organic EL device. Although it is an indispensable requirement for obtaining, it is preferable to contain said compound in a light emitting layer.

  Japanese Patent Application Laid-Open Nos. 2000-21572 and 2002-8860 disclose a method for introducing a linking group into the middle biaryl moiety of a carbazole derivative molecule. Most of the linking groups described in the patent have no substituents, especially when they are rings. However, when the linking group described in the patent is a ring in particular, it has been found that when a substituent is introduced into the linking group, the characteristics as an organic EL device material may be remarkably improved.

  In addition, since many of the linking groups described in the patent have small steric hindrance, the carbazole derivative described in the patent maintains the planarity of the molecule. It has been found that the properties of the compound are further improved by introducing a linking group of a type that destroys the planarity, that is, a group that twists the biaryl moiety of the carbazole derivative.

  Specifically, these substituents are groups described in the general formulas (l) to (o). As a result of evaluating such a carbazole derivative as an organic EL device material, an effect of improving the light emission efficiency and the light emission lifetime was recognized. This is presumed to be a result of improved stability of the compound due to the substituent introduced into the linking group and the sterically bulky linking group, thereby improving the properties of the compound.

  Next, details of each compound according to the present invention will be described.

  First, the compound represented by the general formula (3) according to the present invention will be described.

In the general formula (3), -A 2 is represented by the general formula (4) and may be the same or different.

In the general formula (3), X 2 represents a group represented by the general formulas (l) to (o). The part of * represents the part to connect. m is an integer of 2-4.

In the general formula (4), Ar 2 represents a divalent aromatic hydrocarbon ring group or an aromatic heterocyclic group. Preferably, a divalent phenyl group, biphenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group, pyridyl group, triazyl group, pyrazyl group, quinoxalyl group, and thienyl group which may have a substituent are shown. Most preferably, it is a divalent phenyl group.

  Examples of the substituent include a halogen atom, an alkyl group (for example, a methyl group, an ethyl group, an isopropyl group, a hydroxyethyl group, a methoxymethyl group, a trifluoromethyl group, and a t-butyl group), an alkenyl group (for example, Vinyl group etc.), alkoxycarbonyl group (eg methoxycarbonyl group, ethoxycarbonyl group etc.), alkoxy group (eg methoxy group, ethoxy group etc.), aryloxy group (eg phenoxy group, benzyloxy group), dialkylamino Group (for example, diethylamino group, diisopropylamino group, etc.) is shown. In the case of having the substituent, a methyl group, a phenyl group, and a methoxy group are particularly preferable.

In the general formula (4), R 3 and R 4 each independently represents a hydrogen atom, an alkyl group or an aryl group.

When R 3 and R 4 represent an alkyl group or an aryl group, for example, an alkyl group (for example, a methyl group, an ethyl group, an isopropyl group, a hydroxyethyl group, a methoxymethyl group, a trifluoromethyl group, a t-butyl group, etc. ), Aryl groups (for example, phenyl group, naphthyl group, p-tolyl group, p-chlorophenyl group, mesityl group, etc.) and the like. These groups may be further substituted.

  nc and nd are each an integer of 0 to 4.

  Next, the general formulas (l) to (o) that are linking groups will be described.

In the general formulas (l) to (o), R 101 to R 110 each represent a hydrogen atom, an alkyl group, or an aryl group, and are not connected to each other to form a ring. At least one of R 101 to R 110 is an alkyl group or an aryl group. R 111 to R 118 each represent a hydrogen atom, an alkyl group, or an aryl group. A 1 , A 2 , A 3 and A 4 each represent either —C (R k1 ) or —N═, and at least one is —N═. R k1 represents a hydrogen atom or an alkyl group. A 5 , A 6 , A 7 and A 8 each represent —C (R k2 ) or —N═, and X b represents any one of —NR k3 ,> Si (R k4 ) (R k5 ). To express. R k2 , R k3 , R k4 , and R k5 are each a hydrogen atom, an alkyl group, or an aryl group.

When R k2 , R k3 , R k4 and R k5 represent an alkyl group or an aryl group, the alkyl group or aryl group has the same meaning as the alkyl group or aryl group described in the above R 3 and R 4 , preferably An alkyl group or an aryl group. Of the general formulas (l) to (o), the general formula (l) or (m) is preferable.

  Although the specific example of the compound of this invention and a reference example is shown below, it is not limited to these.

  Next, typical synthesis examples of the above-mentioned compounds according to the present invention are shown below. Other compounds can also be produced by the same method.

(Synthesis Example 2: Synthesis of Exemplary Compound 4-4)
20 g of 4-methylcyclohexanone and 38 g of aniline were heated to reflux in concentrated hydrochloric acid for 40 hours. After neutralizing the reaction solution, ethyl acetate and water were added to the reaction solution to extract the organic layer. After drying with magnesium sulfate, the solvent was distilled off under reduced pressure and purified by column chromatography to obtain 31 g of an amine compound. The amine compound was converted to a bromo compound by Sandmeyer reaction. 1.1 g of the bromo compound and carbazole were heated and stirred for 8 hours using potassium acetate as a base in a xylene solvent using palladium acetate and tri-tert-butylphosphine as catalysts. After completion of the reaction, ethyl acetate, tetrahydrofuran and water were added to extract the organic layer. After drying over magnesium sulfate, the solvent was distilled off under reduced pressure, and the residue was purified by column chromatography and recrystallized from toluene to obtain 1.2 g of Exemplified Compound 4-4 (yield 75%). By NMR spectrum and mass spectrum, it was confirmed to be Exemplified Compound 4-4.

  In the present invention, it is effective to provide a hole blocking layer composed of at least one compound of a styryl compound, a triazole derivative, a phenanthroline derivative, an oxadiazole derivative and a boron derivative between the light emitting layer and the cathode.

  The hole blocking layer has a role of blocking the holes moving from the hole transport layer from reaching the cathode and a compound that can efficiently transport the electrons injected from the cathode toward the light emitting layer. It is formed. The physical properties required of the material constituting the hole blocking layer are higher than the ionization potential of the light emitting layer in order to have high electron mobility and low hole mobility and to efficiently confine holes in the light emitting layer. It is preferable to have a value of ionization potential or a band gap larger than that of the light emitting layer. The hole blocking layer has a function of confining holes and electrons in the light emitting layer and improving luminous efficiency. Preferable examples of the hole blocking layer material satisfying such conditions include compounds represented by the general formulas (5) to (8).

In the general formulas (5) to (8), R a1 to R a3 , R b1 to R b4 , Rc1, and Rc2 each represent an alkyl group, an aryl group, or a heterocyclic group, and A ra to A rc are Each represents an aryl group or a heterocyclic group. Specifically, the alkyl group and aryl group have the same meanings as explained for R 3 and R 4 . Specific examples of the heterocyclic group include a pyrrolyl group, a pyridyl group, a furyl group, and a thienyl group.

  Specific examples of the compounds represented by the general formulas (5) to (8) are listed below, but the present invention is not limited to these.

  Examples of other compounds include exemplified compounds described in JP-A Nos. 2003-31367, 2003-31368, and Japanese Patent No. 2721441.

  In the present invention, it is preferable to use a dopant in combination with the light emitting layer, and an arbitrary one can be selected from known ones used as a dopant for the organic EL element.

  Specific examples of the dopant include quinacridone, DCM, coumarin derivatives, rhodamine, rubrene, decacyclene, pyrazoline derivatives, squarylium derivatives, europium complexes and the like.

  Further, for example, an iridium complex described in JP-A No. 2001-247859 or a compound represented by the formula described on pages 16 to 18 of WO 70,655, for example, tris (2-phenylpyridine) iridium Etc., platinum complexes such as osmium complexes or 2,3,7,8,12,13,17,18-octaethyl-21H, 23H-porphyrin platinum complexes. By using such a phosphorescent compound as a dopant, a light-emitting organic EL device with high internal quantum efficiency can be realized.

  Particularly preferred as these phosphorescent compounds are complex compounds having a group VIII metal as the central metal in the periodic table of elements. More preferably, the central metal is osmium, iridium or a platinum complex compound. Most preferably, it is an iridium complex.

  Examples of these phosphorescent compound dopants include the following compounds.

  These light emitting layers can be formed by forming the above compound by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method.

  The light emitting layer may have a single layer structure composed of one or more of these light emitting materials, or may have a laminated structure composed of a plurality of layers having the same composition or different compositions.

  The phosphorescent compound according to the present invention has a phosphorescence quantum yield in solution of 0.001 or more at 25 ° C. Preferably, it is 0.01 or more. Furthermore, it is preferably 0.1 or more. The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 version, Maruzen) of the 4th edition, Experimental Chemistry Course 7.

  Next, details of each constituent layer of the organic electroluminescence element of the present invention will be described.

  In this invention, although the preferable specific example of the layer structure of an organic EL element is shown below, this invention is not limited to these.

I: Anode / light emitting layer / electron transport layer / cathode
II: Anode / hole transport layer / light emitting layer / electron transport layer / cathode
III: Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode
IV: anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode V: anode / anode buffer layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / Cathode buffer layer / Cathode << Anode >>
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such an electrode substance include conductive transparent materials such as metals such as Au, CuI, indium tin oxide (ITO), SnO 2 , and ZnO. Alternatively, an amorphous material such as IDIXO (In 2 O 3 —ZnO) capable of forming a transparent conductive film may be used. For the anode, a thin film may be formed by depositing these electrode materials by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when the pattern accuracy is not required (100 μm or more) Degree), a pattern may be formed through a mask having a desired shape when the electrode material is deposited or sputtered. When light emission is extracted from the anode, it is desirable that the transmittance is greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 to 1000 nm, preferably 10 to 200 nm.

"cathode"
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al 2 O 3 ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al 2 O 3 ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 1000 nm, preferably 50 nm to 200 nm. In order to transmit light, if either the anode or the cathode of the organic EL element is transparent or translucent, the light emission luminance is improved, which is convenient.

  Next, an injection layer, a hole transport layer, an electron transport layer, etc. used as a constituent layer of the organic EL element of the present invention will be described.

<< Injection layer: electron injection layer, hole injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, exists between the anode and the light emitting layer or the hole transport layer, and between the cathode and the light emitting layer or the electron transport layer. You may let them.

  An injection layer is a layer provided between an electrode and an organic layer in order to lower drive voltage or improve light emission luminance. “Organic EL element and its forefront of industrialization (issued on November 30, 1998 by NTS Corporation) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

  The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer represented by lithium, alkali metal compound buffer layer represented by lithium fluoride, alkaline earth metal compound buffer layer represented by magnesium fluoride, oxide buffer layer represented by aluminum oxide, etc. .

  The buffer layer (injection layer) is preferably a very thin film, and although it depends on the material, the film thickness is preferably in the range of 0.1 nm to 100 nm.

  As described above, the blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film. For example, it is described in JP-A Nos. 11-204258 and 11-204359, and “Organic EL element and its forefront of industrialization” (issued on November 30, 1998 by NTS Corporation). There is a hole blocking layer.

  The hole blocking layer is an electron transport layer in a broad sense, and is made of a material that has a function of transporting electrons and has a very small ability to transport holes. By blocking holes while transporting electrons, And the recombination probability of holes can be improved.

  On the other hand, the electron blocking layer is a hole transport layer in a broad sense, made of a material that has a function of transporting holes and has a very small ability to transport electrons, and blocks electrons while transporting holes. Thus, the probability of recombination of electrons and holes can be improved.

  The hole transport layer is made of a material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer and the electron transport layer can be provided as a single layer or a plurality of layers.

  In the organic EL device of the present invention, it is preferable that the fluorescence maximum wavelength of all the materials of the host of the light emitting layer, the hole transport layer adjacent to the light emitting layer, and the electron transport layer adjacent to the light emitting layer is 415 nm or less.

<Light emitting layer>
The light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. May also be the interface between the light emitting layer and the adjacent layer.

  The light emitting layer can be formed by forming the above compound by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, or an LB method. Although the film thickness as a light emitting layer does not have a restriction | limiting in particular, Usually, it selects in 5 nm-5 micrometers. This light emitting layer may have a single layer structure composed of one or two or more of these light emitting materials, or may have a laminated structure composed of a plurality of layers having the same composition or different compositions. A preferred embodiment of the organic EL device of the present invention is when the light emitting layer is composed of two or more materials, and one of them is the compound of the present invention.

  Further, as described in JP-A-57-51781, this light emitting layer is prepared by dissolving the above light emitting material in a solvent together with a binder such as a resin, and then using a spin coating method or the like. It can be formed as a thin film. There is no restriction | limiting in particular about the film thickness of the light emitting layer formed in this way, Although it can select suitably according to a condition, Usually, it is the range of 5 nm-5 micrometers.

  When there are two or more materials for the light emitting layer, the main component is called a host and the other components are called dopants, and each compound having each partial structure represented by the general formula (3) according to the present invention is a host. It is preferable to be used as In that case, the mixing ratio of the dopant with respect to the host compound as the main component is preferably 0.1% by mass or more and less than 15% by mass.

(Host compound)
“Host compound (also simply referred to as a host)” means a compound having the largest mixing ratio (mass) in a light-emitting layer composed of two or more kinds of compounds. "Dopant compound (also simply referred to as dopant)". For example, if the light emitting layer is composed of two types of compound A and compound B and the mixing ratio is A: B = 10: 90, compound A is a dopant compound and compound B is a host compound. Furthermore, if a light emitting layer is comprised from 3 types of compound A, compound B, and compound C, and the mixing ratio is A: B: C = 5: 10: 85, compound A and compound B are dopant compounds, Compound C is a host compound.

  The host compound of the light emitting layer is preferably an organic compound or a complex. In the present invention, the phosphorescent maximum wavelength is preferably 460 nm or less. Visible light, particularly BGR emission can be achieved by setting the maximum wavelength of the host compound to 460 nm or less. Further, since it has a phosphorescence of 460 nm or less, it has a wide band gap (ionization potential-electron affinity), and therefore advantageously works for a carrier trap type.

  As the host compound, a compound having a high Tg (glass transition temperature) is preferable.

(Dopant)
Next, the dopant will be described.

  There are two types of principles. One is that the carrier recombination occurs on the host to which the carrier is transported to generate an excited state of the host compound, and this energy is transferred to the dopant to obtain light emission from the dopant. The other is the carrier trap type in which the dopant becomes a carrier trap and carrier recombination occurs on the dopant compound, and light emission from the dopant is obtained. In either case, the dopant compound is excited. The condition is that the energy of the state is lower than the energy of the excited state of the host compound.

《Hole transport layer》
The hole transport layer is made of a material having a function of transporting holes, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.

  The hole transport material is not particularly limited, and is conventionally used as a hole charge injection / transport material in an optical transmission material or a well-known material used for a hole injection layer or a hole transport layer of an EL element. Any one can be selected and used.

  The hole transport material has one of hole injection or transport and electron barrier properties, and may be either organic or inorganic. For example, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, Examples thereof include stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymer oligomers, particularly thiophene oligomers.

  As the hole transport material, those described above can be used, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ′, N′-tetraphenyl-4,4′-diaminophenyl; N, N′-diphenyl-N, N′— Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N′-diphenyl-N, N ′ − (4-methoxyphenyl) -4,4′-diaminobiphenyl; N, N, N ′, N′-tetraphenyl-4,4′-diaminodiphenyl ether; 4,4′-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 ′-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4′-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and two more described in US Pat. No. 5,061,569 Having a condensed aromatic ring of, for example, 4,4′-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-30 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 688 are linked in a starburst type (MTDATA).

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

  In the present invention, the hole transport material of the hole transport layer preferably has a fluorescence maximum wavelength at 415 nm or less. That is, the hole transport material is preferably a compound that has a hole transport ability, prevents the emission of light from becoming longer, and has a high Tg.

  This hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, it is about 5-5000 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

《Electron transport layer》
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided as a single layer or a plurality of layers.

  Conventionally, in the case of a single-layer electron transport layer and a plurality of layers, the following materials are used as the electron transport material (also serving as a hole blocking material) used for the electron transport layer adjacent to the cathode side with respect to the light emitting layer. Are known.

  Further, the electron transport layer only needs to have a function of transmitting electrons injected from the cathode to the light emitting layer, and any material can be selected from conventionally known compounds. .

  Examples of materials used for this electron transport layer (hereinafter referred to as electron transport materials) include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone. Derivatives, oxadiazole derivatives and the like. Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material.

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum, Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), etc., and the central metals of these metal complexes are In, Mg, Cu , Ca, Sn, Ga, or Pb can also be used as an electron transport material. In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transport material. In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and similarly to the hole injection layer and the hole transport layer, inorganic such as n-type-Si and n-type-SiC. A semiconductor can also be used as an electron transport material.

  It is preferable that the preferable compound used for an electron carrying layer has a fluorescence maximum wavelength in 415 nm or less. That is, the compound used for the electron transport layer is preferably a compound that has an electron transport ability, prevents emission of longer wavelengths, and has a high Tg.

<< Substrate (also referred to as substrate, substrate, support, etc.) >>
The substrate of the organic EL device of the present invention is not particularly limited to the type of glass, plastic, etc., and is not particularly limited as long as it is transparent. Examples of substrates that are preferably used include glass, quartz, A light transmissive resin film can be mentioned. A particularly preferable substrate is a resin film that can give flexibility to the organic EL element.

  Examples of the resin film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), and cellulose. Examples include films made of triacetate (TAC), cellulose acetate propionate (CAP), and the like.

  An inorganic or organic coating or a hybrid coating of both may be formed on the surface of the resin film.

  The external extraction efficiency at room temperature of light emission of the organic electroluminescence device of the present invention is preferably 1% or more, more preferably 2% or more. Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.

  Further, a hue improving filter such as a color filter may be used in combination.

  The multicolor display device of the present invention comprises at least two types of organic EL elements having different light emission maximum wavelengths. A preferred example of producing the organic EL elements will be described.

<< Method for producing organic EL element >>
As an example of the method for producing the organic EL device of the present invention, a method for producing an organic EL device comprising an anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode will be described.

  First, a desired electrode material, for example, a thin film made of an anode material is formed on a suitable substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 nm to 200 nm. Make it. Next, an organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a hole blocking layer, which are element materials, is formed thereon.

As described above, there are spin coating method, casting method, ink jet method, vapor deposition method, printing method and the like as methods for thinning the organic compound thin film, but it is easy to obtain a homogeneous film and pinholes are not easily generated. In view of the above, the vacuum deposition method or the spin coating method is particularly preferable. Further, a different film forming method may be applied for each layer. When a vapor deposition method is employed for film formation, the vapor deposition conditions vary depending on the type of compound used, but generally a boat heating temperature of 50 to 450 ° C., a vacuum degree of 10 −6 Pa to 10 −2 Pa, a vapor deposition rate of 0. It is desirable to select appropriately within the range of 01 nm to 50 nm / second, substrate temperature of −50 ° C. to 300 ° C., and film thickness of 0.1 nm to 5 μm.

  After the formation of these layers, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a thickness of 1 μm or less, preferably in the range of 50 nm to 200 nm, and a cathode is provided. Thus, a desired organic EL element can be obtained. The organic EL element is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is necessary to consider that the work is performed in a dry inert gas atmosphere.

  The display device of the present invention is provided with a shadow mask only at the time of forming a light emitting layer, and the other layers are common, so patterning such as a shadow mask is unnecessary, and vapor deposition, casting, spin coating, ink jet, and printing are performed on one side. A film can be formed by a method or the like.

  When patterning is performed only on the light-emitting layer, the method is not limited, but a vapor deposition method, an inkjet method, and a printing method are preferable. In the case of using a vapor deposition method, patterning using a shadow mask is preferable.

  In addition, it is also possible to reverse the production order and produce the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode in this order.

  When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 to 40 V with the positive polarity of the anode and the negative polarity of the cathode. Further, even when a voltage is applied with the opposite polarity, no current flows and no light emission occurs. Further, when an AC voltage is applied, light is emitted only when the anode is in the + state and the cathode is in the-state. The alternating current waveform to be applied may be arbitrary.

  The multicolor display device of the present invention can be used as a display device, a display, or various light sources. In a display device or a display, full-color display is possible by using three types of organic EL elements of blue, red, and green light emission.

  Examples of the display device and display include a television, a personal computer, a mobile device, an AV device, a character broadcast display, and an information display in an automobile. In particular, it may be used as a display device for reproducing still images and moving images, and the driving method when used as a display device for reproducing moving images may be either a simple matrix (passive matrix) method or an active matrix method.

  Light emitting sources include home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, light sources for optical sensors, etc. However, it is not limited to this.

  Further, the organic EL element according to the present invention may be used as an organic EL element having a resonator structure.

  Examples of the purpose of use of the organic EL element having such a resonator structure include a light source of an optical storage medium, a light source of an electrophotographic copying machine, a light source of an optical communication processor, and a light source of an optical sensor. Not. Moreover, you may use for the said use by making a laser oscillation.

<Display device>
The organic EL element of the present invention may be used as a kind of lamp such as an illumination or exposure light source, or a projection device that projects an image, or a display device that directly recognizes a still image or a moving image. (Display) may be used. When used as a display device for reproducing moving images, the driving method may be either a simple matrix (passive matrix) method or an active matrix method. Alternatively, a full-color display device can be manufactured by using two or more organic EL elements of the present invention having different emission colors.

  An example of a display device composed of the organic EL element of the present invention will be described below based on the drawings.

  FIG. 1 is a schematic diagram illustrating an example of a display device including organic EL elements. It is a schematic diagram of a display such as a mobile phone that displays image information by light emission of an organic EL element.

  The display 1 includes a display unit A having a plurality of pixels, a control unit B that performs image scanning of the display unit A based on image information, and the like. The control unit B is electrically connected to the display unit A, and sends a scanning signal and an image data signal to each of the plurality of pixels based on image information from the outside. The pixels for each scanning line are converted into image data signals by the scanning signal. In response to this, light is sequentially emitted and image scanning is performed to display image information on the display unit A.

  FIG. 2 is a schematic diagram of the display unit A.

  The display unit A includes a wiring unit including a plurality of scanning lines 5 and data lines 6, a plurality of pixels 3 and the like on a substrate. The main members of the display unit A will be described below.

  FIG. 2 shows a case where the light emitted from the pixel 3 is extracted in the direction of the white arrow (downward). The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a lattice shape and are connected to the pixels 3 at the orthogonal positions (details are shown in Not shown). When a scanning signal is applied from the scanning line 5, the pixel 3 receives an image data signal from the data line 6 and emits light according to the received image data. Full color display is possible by appropriately arranging pixels in the red region, the green region, and the blue region that emit light on the same substrate.

  Next, the light emission process of the pixel will be described.

  FIG. 3 is a schematic diagram of a pixel.

  The pixel includes an organic EL element 10, a switching transistor 11, a driving transistor 12, a capacitor 13, and the like. A full color display can be performed by using red, green, and blue light emitting organic EL elements as the organic EL elements 10 in a plurality of pixels, and juxtaposing them on the same substrate.

  In FIG. 3, an image data signal is applied from the control unit B to the drain of the switching transistor 11 through the data line 6. When a scanning signal is applied from the control unit B to the gate of the switching transistor 11 via the scanning line 5, the driving of the switching transistor 11 is turned on, and the image data signal applied to the drain is supplied to the capacitor 13 and the driving transistor 12. Is transmitted to the gate.

  By transmitting the image data signal, the capacitor 13 is charged according to the potential of the image data signal, and the drive of the drive transistor 12 is turned on. The drive transistor 12 has a drain connected to the power supply line 7 and a source connected to the electrode of the organic EL element 10, and the power supply line 7 connects to the organic EL element 10 according to the potential of the image data signal applied to the gate. Current is supplied.

  When the scanning signal is moved to the next scanning line 5 by the sequential scanning of the control unit B, the driving of the switching transistor 11 is turned off. However, even if the driving of the switching transistor 11 is turned off, the capacitor 13 maintains the potential of the charged image data signal, so that the driving of the driving transistor 12 is kept on and the next scanning signal is applied. Until then, the light emission of the organic EL element 10 continues. When a scanning signal is next applied by sequential scanning, the drive transistor 12 is driven according to the potential of the next image data signal synchronized with the scanning signal, and the organic EL element 10 emits light.

  That is, the organic EL element 10 emits light by the switching transistor 11 and the drive transistor 12 that are active elements for the organic EL element 10 of each of the plurality of pixels, and the light emission of the organic EL element 10 of each of the plurality of pixels 3. It is carried out. Such a light emitting method is called an active matrix method.

  Here, the light emission of the organic EL element 10 may be light emission of a plurality of gradations by a multi-value image data signal having a plurality of gradation potentials, or on / off of a predetermined light emission amount by a binary image data signal. It's okay.

  The potential of the capacitor 13 may be held continuously until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.

  In the present invention, not only the active matrix system described above, but also a passive matrix system light emission drive in which the organic EL element emits light according to the data signal only when the scanning signal is scanned.

  FIG. 4 is a schematic view of a passive matrix display device.

  In FIG. 4, a plurality of scanning lines 5 and a plurality of image data lines 6 are provided in a lattice shape so as to face each other with the pixel 3 interposed therebetween. When the scanning signal of the scanning line 5 is applied by sequential scanning, the pixel 3 connected to the applied scanning line 5 emits light according to the image data signal. In the passive matrix system, the pixel 3 has no active element, and the manufacturing cost can be reduced.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these.

Example 1
<< Preparation of Organic EL Element OLED1-1: For Comparison >>
After patterning on a substrate (made by NH Techno Glass Co., Ltd .: NA-45) with a 150 nm ITO film on glass as the anode, the transparent support substrate provided with this ITO transparent electrode was ultrasonically cleaned with iso-propyl alcohol And dried with dry nitrogen gas, and UV ozone cleaning was performed for 5 minutes.

This transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus. On the other hand, α-NPD, CBP, Ir-12, BC, and Alq 3 are placed in five molybdenum resistance heating boats, respectively. Installed.

Next, after the pressure in the vacuum chamber was reduced to 4 × 10 −4 Pa, α-NPD was vapor-deposited on the transparent support substrate to a thickness of 50 nm to provide a hole injection / transport layer. Furthermore, the heating boat containing CBP and the boat containing Ir-12 were energized independently to adjust the deposition rate of CBP and Ir-12 to 100: 7, so that the film thickness was 30 nm. The light emitting layer was provided by vapor deposition.

Next, BC was vapor-deposited to provide a 10 nm thick hole blocking layer. Further, Alq 3 was deposited to provide an electron transport layer having a thickness of 40 nm.

Next, the vacuum chamber is opened and a stainless steel rectangular perforated mask is placed on the electron injection layer. On the other hand, 3 g of magnesium is put into a molybdenum resistance heating boat, and 0.02 of silver is put into a tungsten evaporation basket. 5 g was added and the vacuum chamber was again depressurized to 2 × 10 −4 Pa. Then, the magnesium-containing boat was energized to deposit magnesium at a deposition rate of 1.5 nm / sec to 2.0 nm / sec. The basket was heated and silver was vapor-deposited at a vapor deposition rate of 0.1 nm / second to produce a comparative organic EL element OLED1-1 as a cathode (200 nm) made of the mixture of magnesium and silver.

<< Production of Organic EL Elements OLED1-2 to 1-33 >>
In preparation of said organic EL element OLED1-1, it is the same except having changed CBP used for preparation of a light emitting layer into Comparative 1-10 of Table 1, the compound of a reference example, and the exemplary compound which concerns on this invention. Thus, organic EL elements OLED1-2 to 1-33 were produced.

<< Characteristic evaluation of organic EL elements >>
The following evaluation was performed about each of obtained organic EL element OLED1-1 to 1-33.

(Luminance brightness, time to reduce brightness by half)
Luminance (L) [cd / m 2 ] when each element of the organic EL elements OLED1-1 to 1-33 is supplied with a current of 2.5 mA / cm 2 in a dry nitrogen gas atmosphere at a temperature of 23 degrees. In addition, the time (τ) during which the luminance was reduced by half was measured. Here, CS-1000 (manufactured by Minolta) was used for measurement of light emission luminance and the like.

  In describing the evaluation results in Table 1, the light emission luminance and the time during which the luminance is reduced by half (also referred to as half-life) are expressed as relative values when each characteristic value of the organic EL element OLED1-1 is 100. The obtained results are shown in Table 1.

  As is clear from Table 1, compared with organic EL elements OLED1-1 to 1-9, 1-21, and 1-22 using comparative compounds, organic EL elements OLED1-15 to 15 using the compounds according to the present invention. It can be seen that each of the samples 1-20, 1-32 and 1-33 is excellent in both emission luminance and half life.

  Furthermore, the organic EL elements OLED1-10G to OLED1-20G and 23G-33G were similarly changed except that Ir-12, which is a phosphorescent compound, was replaced with Ir-1, and Ir-12 was changed to Ir-9. The organic EL elements OLED1-20R and 23R-33R were produced from the organic EL elements OLED1-10R in the same manner except that the above was changed. In each of the organic EL elements, the same effect as that obtained when Ir-12 was used was obtained. In addition, green light emission was obtained from the element using Ir-1, and red light emission was obtained from the element using Ir-9.

Moreover, as a result of measuring the voltage required to produce the luminance of 50 cd / m 2 using the produced organic EL elements OLED1-4, 1-10, 1-11, and 1-12, the organic EL element OLED1- When the drive voltage at 4 is 0V, the drive voltages of the organic EL elements OLED1-10, 1-11, and 1-12 are -1.0V, -0.7V, and -0.6V as relative values, respectively. Thus, it was confirmed that the non-substituted phenylene group was operated at a low driving voltage as compared with the case where the unsubstituted phenylene group was used as the host compound of the light emitting layer.

Example 2
<< Production of Organic EL Elements OLED2-1 to 2-12 >>
In the production of the organic EL element OLED1-1 described in Example 1, the organic EL element OLED2 was similarly prepared except that the host compound of the light emitting layer and the compound of the hole blocking layer were changed to the respective compounds described in Table 2. -1 to 2-12 were produced.

  Each of the obtained organic EL elements OLED2-1 to 2-12 was evaluated in the same manner as in Example 1 for evaluating the light emission luminance and the time to reduce the luminance by half, and Table 2 shows the results obtained.

  In addition, each evaluation result of Table 2 was represented by the relative value when the light-emitting luminance and half-life of the organic EL element OLED2-1 were set to 100, respectively.

  As is apparent from Table 2, each sample of the organic EL elements OLEDs 2-11 to 2-12 using the compound according to the present invention, compared to the organic EL elements OLED2-1 and 2-2 using the comparative compound, It can be seen that both the luminance and the half-life are excellent.

  In addition, the same effect was obtained when the compound of the present invention was used as the compound of the light emitting layer. In this case, the improvement effect of both emission luminance and half-life was obtained when TAZ, OXD7, DPVBi, B1, and B2 were used rather than the compound of the hole blocking layer being BC and compound A1.

Example 3
<< Production of Organic EL Elements OLED3-1 to 3-28 >>
In the production of the organic EL element OLED1-1 described in Example 1, the organic EL element OLED3 was similarly prepared except that the host compound of the light emitting layer and the compound of the hole blocking layer were changed to the respective compounds described in Table 3. -1-3 to 28 were produced.

  Each of the obtained organic EL elements OLED3-1 to 3-28 was evaluated in the same manner as in Example 1 for evaluating the light emission luminance and the time during which the luminance was reduced by half.

  In addition, each evaluation result of Table 3 was represented with the relative value when the light-emitting luminance and half-life of the organic EL element OLED3-1 are set to 100, respectively.

  As is clear from Table 3, it can be seen that each sample using the compound according to the present invention is superior in both emission luminance and half-life compared to the case where the comparative compound is used.

  Even when BC, compounds A1, OXD7, TAZ, and B1 were used as the hole blocking material, the compound of the present invention showed higher characteristics in terms of both emission luminance and emission lifetime than the comparative compounds.

Example 5
<Production of full-color display device>
(Preparation of blue light-emitting organic EL device)
In the production of the organic EL element OLED1-1 described in Example 1, m-MTDATXA was used instead of α-NPD for the hole injection / transport layer, and Compound 4-4 + Ir-12 (deposition rate was 100) was used for the light emitting layer. In the same manner, except that the cathode buffer layer and the cathode were respectively formed by depositing 0.5 nm of lithium fluoride and 110 nm of aluminum by using BC for the electron transport layer. A light emitting organic EL device was produced.

(Production of green light-emitting organic EL device)
In the production of the blue light-emitting organic EL element, a green light-emitting organic EL element was obtained in the same manner except that Ir-1 (adjusted so that the deposition rate was 100: 7) was used instead of Ir-12 in the light-emitting layer. Was made.

(Production of red light emitting organic EL device)
In the production of the blue light-emitting organic EL element, a red light-emitting organic EL element was obtained in the same manner except that Ir-9 (adjusted so that the deposition rate was 100: 7) was used instead of Ir-12 in the light-emitting layer. Was made.

  The red, green and blue light-emitting organic EL elements produced above are juxtaposed on the same substrate to produce an active matrix type full-color display device having the form shown in FIG. 1, and FIG. 2 shows the produced display device. Only the schematic diagram of the display part A is shown. That is, a wiring portion including a plurality of scanning lines 5 and data lines 6 on the same substrate, and a plurality of juxtaposed pixels 3 (light emission color is a red region pixel, a green region pixel, a blue region pixel, etc.) The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a lattice shape and are connected to the pixels 3 at the orthogonal positions ( Details are not shown). The plurality of pixels 3 are driven by an active matrix system provided with an organic EL element corresponding to each emission color, a switching transistor as an active element, and a driving transistor, and a scanning signal is applied from a scanning line 5. Then, an image data signal is received from the data line 6 and light is emitted according to the received image data. In this way, a full color display device was produced by appropriately juxtaposing the red, green, and blue pixels.

  It was confirmed that by driving the full-color display device, a bright full-color moving image display having high luminance, high durability, and clearness could be obtained.

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line 7 Power supply line 10 Organic EL element 11 Switching transistor 12 Drive transistor 13 Capacitor A Display part B Control part

Claims (8)

  1. The organic electroluminescent element characterized by containing the compound represented by following General formula (3).
    General formula (3)
    X 2 - (A 2) m
    Wherein, -A 2 is represented by the following general formula (4) may be the same or different.
    In the formula, Ar 2 is a divalent aromatic hydrocarbon ring group or an aromatic heterocyclic group. R 3 and R 4 each represent a hydrogen atom, an alkyl group or an aryl group. m represents an integer of 2 to 4, and nc and nd each represents an integer of 0 to 4. X 2 is any one selected from linking groups represented by the following general formulas (l) to (o).
    In the formula, R 101 to R 110 each represent a hydrogen atom, an alkyl group, or an aryl group, and are not connected to each other to form a ring. At least one of R 101 to R 110 is an alkyl group or an aryl group. R 111 to R 118 each represent a hydrogen atom, an alkyl group, or an aryl group. A 1 to A 4 each represent either —C (R k1 ) or —N═, and at least one of them is —N═. R k1 represents a hydrogen atom or an alkyl group. A 5 to A 8 each represent —C (R k2 ) or —N═, and X b represents —NR k3 or> Si (R k4 ) (R k5 ). R k2 to R k5 each represent a hydrogen atom, an alkyl group, or an aryl group. In addition, * represents a connection part. ]
  2.   The organic electroluminescence device according to claim 1, wherein a hole blocking layer is provided between the light emitting layer and the cathode.
  3.   The organic electroluminescence device according to claim 2, wherein the hole blocking layer is composed of at least one compound of a styryl compound, a triazole derivative, a phenanthroline derivative, an oxadiazole derivative, or a boron derivative.
  4. 3. The organic electro of claim 2, wherein the hole blocking layer is composed of at least one compound represented by the following general formula (5), (6), (7) or (8). Luminescence element.
    [Wherein, R a1 to R a3 , R b1 to R b4 , R c1 , and R c2 each represents an alkyl group, an aryl group, or a heterocyclic group, and A ra to A rc each represents an aryl group or a complex Represents a cyclic group. ]
  5.   The light emitting layer contains the compound represented by the said General formula (3), The organic electroluminescent element of any one of Claims 1-4 characterized by the above-mentioned.
  6.   A phosphorescent compound is contained, The organic electroluminescent element of any one of Claims 1-5 characterized by the above-mentioned.
  7.   7. The organic electroluminescence device according to claim 6, wherein the phosphorescent compound is osmium, iridium, or a platinum complex compound.
  8.   A display device comprising the organic electroluminescence element according to claim 1.
JP2009146249A 2002-11-26 2009-06-19 Organic electroluminescence element and display device having the same Active JP5104816B2 (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000068059A (en) * 1998-08-24 2000-03-03 Toyo Ink Mfg Co Ltd Organic electroluminescent element material and organic electroluminescent element using the same
JP2004522276A (en) * 2001-05-16 2004-07-22 ザ ユニバーシティ オブ サザン カリフォルニア High-efficiency multi-colored electric field phosphorescent oled

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000068059A (en) * 1998-08-24 2000-03-03 Toyo Ink Mfg Co Ltd Organic electroluminescent element material and organic electroluminescent element using the same
JP2004522276A (en) * 2001-05-16 2004-07-22 ザ ユニバーシティ オブ サザン カリフォルニア High-efficiency multi-colored electric field phosphorescent oled

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