JP2013235994A - Organic electroluminescent element, display device, and lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic electroluminescent element excellent in luminous efficiency, element life, and low-voltage driving, and to provide a display device and a lighting device.SOLUTION: The organic electroluminescent element contains a metal complex represented by general formula (1): MLL(L)[wherein MLrepresents a partial structure represented by general formula (2), M represents a metal atom of groups 8-10 of the periodic table of the elements, Lto Leach represent a divalent ligand, and n represents 1 or 0].

Description

  The present invention relates to an organic electroluminescence element, a display device, and a lighting device.

  Conventionally, as a light-emitting electronic display device, there is an electroluminescence display (hereinafter referred to as ELD). Examples of the constituent elements of ELD include inorganic electroluminescent elements and organic electroluminescent elements (hereinafter also referred to 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 EL 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 (excitons) are generated by injecting electrons and holes into the light-emitting layer and recombining them. The device 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. Therefore, 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 viewpoints of space saving and portability.

  However, in organic EL elements for practical use in the future, development of organic EL elements that emit light efficiently and with high luminance with lower power consumption is desired.

  Since the publication of an organic EL device using phosphorescence emission from an excited triplet from Princeton University (MA Baldo et al., Nature, 395, 151-154 (1998)), phosphorescence at room temperature Research on materials that exhibit this has become active. For example, M.M. A. Baldo et al. , Nature, 403, 17, 17, 750-753 (2000).

  When the excited triplet is used, the upper limit of the internal quantum efficiency is 100%. In principle, the luminous efficiency is four times that of the excited singlet, and there is a possibility that almost the same performance as a cold cathode tube can be obtained. Therefore, it is attracting attention as a lighting application.

Many compounds have been studied mainly for heavy metal complexes such as iridium complexes. In addition, studies using tris (2-phenylpyridine) iridium as a dopant have been made. Other dopants include L ₂ Ir (acac), for example, (ppy) ₂ Ir (acac), tris (2- (p-tolyl) pyridine) iridium (Ir (ptpy) ₃ ), tris (benzo [h] quinoline) Studies using iridium (Ir (bzq) ₃ ) and the like are being conducted. These metal complexes are generally called orthometalated iridium complexes. In addition, L abbreviated as described above represents a ligand, acac represents acetylacetone, ppy represents phenylpyridine, ptpy represents p-tolylpyridine, and bzq represents benzo [h] quinoline.

  In addition, attempts have been made to form devices using various iridium complexes.

  Furthermore, in order to obtain high luminous efficiency, a hole transporting compound is used as a phosphorescent compound host, and various electron transporting materials are used as phosphorescent compound hosts, and these are doped with a novel iridium complex. The use is also disclosed.

  In either case, the light emission brightness and light emission efficiency of the light emitting device are greatly improved compared to conventional devices because the emitted light is derived from phosphorescence. There was a problem that it was lower than the conventional element.

  As described above, it is difficult for phosphorescent highly efficient light-emitting materials to shorten the light emission wavelength and improve the light emission lifetime of the device, and the performance that can withstand practical use cannot be sufficiently achieved.

  Regarding wavelength shortening, introduction of electron-withdrawing groups such as fluorine atoms, trifluoromethyl groups, and cyano groups into phenylpyridine as substituents, and introduction of picolinic acid and pyrazabole-based ligands as ligands It is known.

  However, with these ligands, the emission wavelength of the light-emitting material is shortened to achieve blue, and a high-efficiency device can be achieved. On the other hand, the light-emitting lifetime of the device is greatly deteriorated, so an improvement in the trade-off is required. It was.

  It is disclosed that a metal complex having phenylpyrazole as a ligand is a light emitting material having a short emission wavelength.

  Furthermore, a metal complex formed from a ligand having a partial structure in which a 6-membered ring is condensed to a 5-membered ring of phenylpyrazole is disclosed.

  In addition, in U.S. Patent Application Publication No. 2006/251923, International Publication No. 2007/097149, and International Publication No. 2007/097153, an iridium complex having a ligand having a phenylimidazole skeleton is used. It is disclosed that it is useful as a light-emitting dopant in organic EL devices.

  However, organic EL devices using conventionally disclosed light emitting dopants are still insufficient in terms of light emission efficiency, driving voltage, and lifetime. In the light emitting layer of the organic EL device, the light emitting dopant may be uniformly dispersed in the host compound due to problems such as carrier transportability, concentration quenching due to aggregation of the light emitting dopant, and quenching due to interaction between excitons. Although desirable, there has not yet been found a material that solves the above problems and exhibits sufficient device performance.

  As described above, many light emitting materials have been studied for synthesis mainly on iridium complexes and platinum complexes. From the viewpoint of providing an organic EL device having high light emission efficiency, low driving voltage, and long life. It is still insufficient and further solutions are being sought.

  Furthermore, as described in, for example, Japanese Patent Application Laid-Open No. 2002-302671 or International Publication No. 2007/006380, a wet method (wet process or the like) is required due to demands for large area, low cost, and high productivity. Can be formed at a lower temperature than the vacuum process, which can reduce the damage to the underlying organic layer, and has high expectations for improving luminous efficiency and device life. It is sent.

  In these documents, wet film formation using an ionic metal complex is realized. However, in order to realize wet film formation in an organic EL element using blue phosphorescence emission, from a practical point of view, currently known luminescent materials have solubility in solvents, solution stability, and driving voltage. In terms of device life, etc., it was still inadequate, and it was found that development of further improved technology is essential.

  On the other hand, as one of the means for improving the emission lifetime of the organic electroluminescent material, the search for the host compound and the dopant compound used in the light emitting layer has been conducted for a long time, and a structure that can be practically used is being found. . However, small changes in the structure of these compounds have a large effect on the light emission lifetime of the device, and many problems remain to be solved.

In recent years, a metal complex compound having a specific ligand (benzimidazole mother nucleus) as a blue phosphorescent compound having high potential, high external extraction efficiency, and long life. Is disclosed (for example, refer to Patent Documents 1 and 2).
In the organic electroluminescence elements disclosed in Patent Document 1 and Patent Document 2, some improvement is recognized in terms of light emission efficiency and light emission lifetime, and the compounds exemplified in those patent documents are organic electroluminescence. When producing an element, particularly when forming an organic functional layer containing the compound using a vapor deposition method, there is a problem in stability, that is, when producing an organic electroluminescence element, each of the above patents. When repeated deposition was performed using compounds disclosed in the literature, it was found that there was a large difference in the lifetime of the obtained organic electroluminescent device between the initial stage and the end of the deposition, and an immediate improvement was made. It has been demanded.

US Patent No. 2011/57559 International Publication No. 2008/90795

  The present invention has been made in view of the above problems, and its solution is to use a metal complex having excellent thermal stability in the formation of an organic layer by a vapor deposition method. An organic electroluminescence element that can be driven by voltage and has little voltage increase during driving, and a display device and an illumination device using the organic electroluminescence element.

  As a result of intensive studies in view of the above problems, the present inventor has an organic layer including at least one light emitting layer as an organic electroluminescence element, and at least one of the organic layers is repeatedly formed during the formation of the organic layer. When vapor deposition is performed, by including a metal complex having a specific ligand represented by the general formula (1) excellent in thermal stability, it is excellent in external extraction efficiency and device lifetime, and can be driven at a low voltage. It has been found that an organic electroluminescence element capable of being driven and having a small voltage rise during driving can be realized, and has reached the present invention.

  That is, the above problem of the present invention is solved by the following means.

  1. An organic electroluminescence device having an organic layer including at least one light emitting layer, wherein at least one of the organic layers contains a metal complex represented by the following general formula (1) Luminescence element.

〔式中、Ｘは、炭素原子又は窒素原子を表す。Ａ^１は、Ｘ−Ｃとともに５員もしくは６員の芳香族炭化水素環又は芳香族複素環を形成するのに必要な原子群を表す。Ａ^２は、Ｎ−Ｃ−Ｎと共に５員の芳香族複素環を形成するのに必要な原子群を表す。Ａ^３は、Ｃ−Ｃ−Ｃと共に６員の芳香族炭化水素環又は芳香族複素環を形成するのに必要な原子郡を表す。Ｒ^１、Ｒ^２及びＲ^３は、それぞれＡ^１、Ａ^２及びＡ^３に置換可能な置換基を表す。ｎ１は０〜４の整数を表し、ｎ２は０〜２の整数を表し、ｎ３は０〜２の整数を表す。Ｒ^１〜Ｒ^３が複数ある場合には、互いに同一の置換基であっても良いし異なる置換基であってもよい。Ａｒは、置換基を有してもよい５員もしくは６員の芳香族炭化水素環又は複素芳香族環を表す。ｎ４は、１〜３の整数を表す。Ａｒが複数ある場合、Ａｒは同一でも異なっていてもよく、Ａｒは、Ａ^３によって形成される環と共に縮合環を形成してもよい。Ｒ^４及びＲ^５は、各々水素原子又は置換基を表し、Ｒ^４及びＲ^５の少なくとも一方は、置換基を有しても良い炭素数５〜２０の非環状アルキル基を表す。〕
２．前記一般式（２）で表される部分構造が、下記一般式（３）で表される部分構造であることを特徴とする第１項に記載の有機エレクトロルミネッセンス素子。 General formula (1)
ML ¹ · L ² · (L ³ ) _n
[Wherein, ML ¹ represents a partial structure represented by the following general formula (2), and M represents a group 8-10 metal atom in the periodic table of elements. L ^{1 to} L ³ each represents a divalent ligand, and L ^{1 to} L ³ may be the same as or different from each other, and may be bonded to each other. n represents 1 or 0. ]

[Wherein, X represents a carbon atom or a nitrogen atom. A ¹ represents an atomic group necessary for forming a 5- or 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring together with X—C. A ² represents an atomic group necessary for forming a 5-membered aromatic heterocyclic ring together with N—C—N. A ³ represents an atomic group necessary for forming a 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring together with C—C—C. R ¹ , R ² and R ³ each represent a substituent capable of substituting for A ¹ , A ² and A ³ . n1 represents an integer of 0 to 4, n2 represents an integer of 0 to 2, and n3 represents an integer of 0 to 2. When there are a plurality of R ^{1 to} R ³ , the substituents may be the same as or different from each other. Ar represents a 5-membered or 6-membered aromatic hydrocarbon ring or heteroaromatic ring which may have a substituent. n4 represents an integer of 1 to 3. When Ar is more, Ar may be the same or different, Ar may form a fused ring with the ring formed by A ^3. R ⁴ and R ⁵ each represent a hydrogen atom or a substituent, and at least one of R ⁴ and R ⁵ represents an acyclic alkyl group having 5 to 20 carbon atoms that may have a substituent. ]
2. 2. The organic electroluminescent element according to item 1, wherein the partial structure represented by the general formula (2) is a partial structure represented by the following general formula (3).

〔式中、Ａｒは、置換基を有してもよい５員もしくは６員の芳香族炭化水素環又は複素芳香族環を表す。ｎ４は１〜３の整数を表す。Ａｒが複数ある場合、Ａｒは同一でも異なっていてもよく、Ａｒが置換しているベンゼン環と共に縮合環を形成してもよい。Ｒ^４及びＲ^５は、各々水素原子又は置換基を表し、Ｒ^４及びＲ^５の少なくとも一方は、炭素数が５〜２０の範囲にある非環状アルキル基を表す。Ｒ^３は、ベンゼン環に置換可能な置換基を表す。ｎ３は、０〜２の整数を表す。Ｒ^３が複数ある場合には、Ｒ^３は、互いに同一の置換基であっても良いし異なる置換基であってもよい。Ｒ^１１〜Ｒ^１６は、各々水素原子又は置換基を表す。〕
３．前記一般式（２）におけるＲ^４及びＲ^５の少なくとも一方が、炭素数が５〜１５の範囲にある非環状分岐アルキル基であることを特徴とする第１項に記載の有機エレクトロルミネッセンス素子。

[Wherein, Ar represents a 5-membered or 6-membered aromatic hydrocarbon ring or heteroaromatic ring which may have a substituent. n4 represents an integer of 1 to 3. When there are a plurality of Ars, Ars may be the same or different, and may form a condensed ring together with the benzene ring substituted by Ar. R ⁴ and R ⁵ each represent a hydrogen atom or a substituent, and at least one of R ⁴ and R ⁵ represents an acyclic alkyl group having 5 to 20 carbon atoms. R ³ represents a substituent that can be substituted on the benzene ring. n3 represents an integer of 0 to 2. When there are a plurality of R ^{3 s} , R ³ may be the same or different substituents. R ^{11 to} R ¹⁶ each represent a hydrogen atom or a substituent. ]
3. 2. The organic electroluminescence device according to item 1, wherein at least one of R ⁴ and R ⁵ in the general formula (2) is an acyclic branched alkyl group having 5 to 15 carbon atoms.

4). 3. The organic electroluminescence device according to item 2, wherein at least one of R ⁴ and R ⁵ in the general formula (3) is an acyclic branched alkyl group having 5 to 15 carbon atoms.

  5. 4. The organic electroluminescence device according to item 1 or 3, wherein Ar in the general formula (2) is a 5-membered or 6-membered aromatic hydrocarbon ring.

  6). The organic electroluminescent element according to the second or fourth item, wherein Ar in the general formula (3) is a 5-membered or 6-membered aromatic hydrocarbon ring.

  7). 4. The organic electroluminescence device according to item 1 or 3, wherein Ar in the general formula (2) is a 5-membered or 6-membered aromatic heterocyclic ring.

  8). The organic electroluminescence device according to item 2 or 4, wherein Ar in the general formula (3) is a 5-membered or 6-membered aromatic heterocyclic ring.

9. The organic electroluminescent element according to any one of items 1 to 8, wherein L ^{1 to} L ³ in the general formula (1) all have the same chemical structure.

10. The organic electroluminescent element according to any one of items 1 to 9, wherein L ¹ and L ² in the general formula (1) have different chemical structures.

11. In addition to connecting at least one of L ^{1 to} L ³ in the general formula (1) via M, L ¹ and L ² , L ² and L ³ , or L ¹ and L ³ are The organic electroluminescence device according to any one of items 1 to 8, wherein the organic electroluminescence device is connected via a valent linking group.

  12 The organic electroluminescence device according to any one of items 1 to 11, wherein M in the general formula (1) is iridium.

  13. 13. The organic electroluminescent element according to any one of items 1 to 12, wherein the organic layer containing the metal complex represented by the general formula (1) is a light emitting layer.

  14 14. The organic electroluminescence device according to any one of items 1 to 13, which emits white light.

  15. A display device comprising the organic electroluminescence element according to any one of items 1 to 14.

  16. An organic electroluminescence device according to any one of items 1 to 14 is provided.

  By using the above-mentioned means of the present invention, a metal complex having excellent thermal stability during vapor deposition for forming an organic layer is used, organic extraction efficiency and device lifetime are excellent, low voltage driving is possible, and organic voltage is low during driving. An electroluminescent element and a display device and a lighting device using the same can be provided.

  It is presumed that the above problem can be solved by the configuration defined in the present invention for the following reason.

  When forming an organic layer, especially a light emitting layer by a vapor deposition method, when vapor deposition was repeated, decomposition | disassembly of a metal complex compound advanced, and this was a cause of deterioration of element lifetime. As a means of suppressing the decomposition of the metal complex compound, it was speculated that it was necessary to control the interaction at the molecular level. That is, it was estimated that there is a possibility that the thermal stability of the metal complex compound can be improved by controlling the association or arrangement of the metal complexes with substituents.

  With this assumption in mind, as a result of intensive studies on the structure of the optimum metal complex compound, it was found that there is a specific structure with little change in characteristics even after repeated deposition. As a result of studying the tendency of the compound structure in more detail, the metal complex compound group having a structure having a bulky substituent at a specific position exhibits high thermal stability even in an environment where it is repeatedly heated. As a result, the present invention has been reached.

The schematic diagram which shows an example of the display apparatus comprised from the organic EL element of this invention Schematic diagram of the display section A constituting the display device shown in FIG. Schematic of the lighting device of the present invention Schematic diagram of the lighting device of the present invention

In the organic electroluminescence device of the present invention, at least one of the organic layers contains a metal complex represented by ML ¹ · L ² · (L ³ ) _n , and ML ¹ which is one of ligands. However, it has a partial structure represented by the above general formula (2), contains a metal complex having excellent thermal stability during vapor deposition, is excellent in external extraction efficiency and device life, and is driven at low voltage. An organic electroluminescence element that can be driven and has a small voltage increase during driving can be realized. This feature is a technical feature common to the inventions according to claims 1 to 16.

  As an embodiment of the present invention, the partial structure represented by the general formula (2) is further divided into the partial structure represented by the general formula (3) from the viewpoint that the effect intended by the present invention can be further expressed. It is preferable that

In addition, at least one of R ⁴ and R ⁵ in the general formula (2) is an acyclic branched alkyl group having 5 to 15 carbon atoms, or R ⁴ and R in the general formula (3). at least one of ^5, carbon atoms is preferred acyclic branched alkyl groups in the range of 5-15.

  Ar in the general formula (2) is a 5-membered or 6-membered aromatic hydrocarbon ring, or Ar in the general formula (3) is a 5-membered or 6-membered aromatic hydrocarbon ring. Preferably there is.

  In addition, Ar in the general formula (2) is a 5-membered or 6-membered aromatic heterocyclic ring, or Ar in the general formula (3) is a 5-membered or 6-membered aromatic heterocyclic ring. preferable.

Moreover, the the ^L 1 ~L ³ in the general formula (1), it is preferred that all are the same chemical structure. Further, L ¹ and L ² in the formula (1) are each preferably a different chemical structure. In addition, at least one of L ^{1 to} L ³ in the general formula (1) is linked via M, L ¹ and L ² , L ² and L ³ , or L ¹ and L ³ are It is also one of the preferable embodiments that they are linked via a divalent linking group.

  M in the general formula (1) is preferably iridium.

  Moreover, it is a preferable aspect that the organic layer containing the metal complex represented by the general formula (1) is a light emitting layer.

  Moreover, it is a preferable aspect that the organic electroluminescent element of the present invention emits white light.

  In addition, the organic electroluminescence element of the present invention is provided to form a display device or a lighting device.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, "-" shown in this invention is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

<< Metal Complex Represented by General Formula (1) >>
The organic EL device of the present invention is characterized in that at least one of the organic layers contains a metal complex represented by the following general formula (1).

General formula (1)
ML ¹ · L ² · (L ³ ) _n
In the general formula (1), ML ¹ represents a partial structure represented by the following general formula (2), and M represents a group 8-10 metal atom in the periodic table. L ^{1 to} L ³ each represents a divalent ligand, and L ^{1 to} L ³ may be the same or different, and may be bonded to each other. n represents 1 or 0.

In the general formula (2), X represents a carbon atom or a nitrogen atom. A ¹ represents an atomic group necessary for forming a 5- or 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring together with X—C. A ² represents an atomic group necessary for forming a 5-membered aromatic heterocyclic ring together with N—C—N. A ³ represents an atomic group necessary for forming a 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring together with C—C—C. R ¹ , R ² and R ³ each represent a substituent capable of substituting for A ¹ , A ² or A ³ . n1 represents an integer of 0 to 4, n2 represents an integer of 0 to 2, and n3 represents an integer of 0 to 2. When there are a plurality of R ^{1 to} R ³ , the substituents may be the same as or different from each other. Ar represents a 5-membered or 6-membered aromatic hydrocarbon ring or heteroaromatic ring which may have a substituent. n4 represents 1-3. When Ar is more, Ar may be the same or different, Ar may form a fused ring with the ring formed by A ^3. R ⁴ and R ⁵ each represent a hydrogen atom or a substituent, and at least one of R ⁴ and R ⁵ represents an acyclic alkyl group having 5 to 20 carbon atoms that may have a substituent.

  Furthermore, it is preferable that the partial structure represented by the general formula (2) is a partial structure represented by the following general formula (3).

In the general formula (3), Ar represents a 5-membered or 6-membered aromatic hydrocarbon ring or heteroaromatic ring which may have a substituent. n4 represents an integer of 1 to 3. When there are a plurality of Ars, Ars may be the same or different, and may form a condensed ring together with the benzene ring substituted by Ar. R ⁴ and R ⁵ each represent a hydrogen atom or a substituent, and at least one of R ⁴ and R ⁵ represents an acyclic alkyl group having 5 to 20 carbon atoms. R ³ represents a substituent that can be substituted on the benzene ring. n3 represents an integer of 0 to 2. When there are a plurality of R ^{3 s} , R ³ may be the same or different from each other. R ^{11 to} R ¹⁶ each represent a hydrogen atom or a substituent.

  In the general formula (1), the group 8-10 metal atom in the periodic table of elements represented by M is preferably Os, Ir, Pt, Rh, and more preferably Ir.

  In the general formulas (2) and (3), examples of the 5-membered aromatic heterocycle represented by Ar include an oxazole ring, a thiazole ring, an oxadiazole ring, an isoxazole ring, a thiadiazole ring, and a thiatriazole ring. , Isothiazole ring, thiophene ring, furan ring, pyrrole ring, imidazole ring, pyrazole ring, triazole ring and the like. Moreover, a benzene ring is mentioned as a 6-membered aromatic hydrocarbon ring. Examples of the 6-membered aromatic heterocycle include a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, and a triazine ring.

In the general formula (2), R ^{1 to} R ³ are each an alkyl group (for example, a methyl group, an ethyl group, or a propyl group) as a substituent that represents a substituent that can be substituted on A ¹ , A ^{2, or} A ^3. , Isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (for example, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (for example, Vinyl group, allyl group, etc.), alkynyl group (for example, ethynyl group, propargyl group, etc.), aromatic hydrocarbon group (aromatic carbocyclic group, aryl group, etc.), for example, phenyl group, p-chlorophenyl group, Mesityl, tolyl, xylyl, naphthyl, anthryl, azulenyl, acenaphthenyl, fluorenyl , Phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.), aromatic heterocyclic group (for example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, , 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, Thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group Shows one replaced by a nitrogen atom Quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (for example, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, propyl) Oxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.) ), Alkylthio group (for example, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (for example, cyclopentylthio group, cyclohexylthio group) ), Arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxy Carbonyl group (for example, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group) Octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), Acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc. ), Acyloxy groups (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide groups (for example, methylcarbonylamino group, ethylcarbonyl) Amino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonyl Mino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentyl) Aminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (eg methyl Ureido group, ethylureido group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group naphthy Ureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group etc.), alkylsulfonyl group (eg methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group etc.), arylsulfonyl group or heteroarylsulfonyl group (For example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethyl) Ruamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (for example, fluorine atom, chlorine atom, bromine atom, etc.) , Fluorinated hydrocarbon group (for example, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, Triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.). These substituents may be further substituted with the above substituents. A plurality of these substituents may be bonded to each other to form a ring.

In the general formula (3), the substituents represented by R ³ and R ^{11 to} R ¹⁶ are the same groups as the substituents represented by R ^{1 to} R ³ in the general formula (2) mentioned above. Can be mentioned.

In the general formulas (2) and (3), R ⁴ and R ⁵ each represent a hydrogen atom or a substituent, and at least one of R ⁴ and R ⁵ has 5 carbon atoms that may have a substituent. Represents -20 acyclic alkyl groups.

The acyclic alkyl group having 5 to 20 carbon atoms represented by R ⁴ or R ⁵ is preferably a linear alkyl group having 5 to 20 carbon atoms or a branched alkyl group having 5 to 20 carbon atoms. More preferably, R ⁴ or R ⁵ is an acyclic branched alkyl group having 5 to 15 carbon atoms. Among the above, it is more preferable that at least one of R ⁴ and R ⁵ is a branched alkyl group having 5 to 10 carbon atoms. In the case of a branched alkyl group, α-branch, β-branch, γ-branch and the like are preferable, and an alkyl group having a plurality of branches and a bilaterally symmetrical alkyl group are also preferable. Further, it is most preferable that R ³ and R ⁴ are each composed only of the acyclic alkyl group having 5 to 20 carbon atoms.

Specific examples of the acyclic alkyl group having 5 to 20 carbon atoms represented by R ⁴ or R ⁵ are shown below, but the present invention is not limited only to these exemplified acyclic alkyl group groups.

In addition, the * mark described in the following exemplification is a 6-membered aromatic hydrocarbon ring formed by A ³ and C—C—C represented by R ⁴ or R ⁵ in the general formula (2) or It represents a bonding site with an aromatic heterocyclic ring, or a bonding site in the phenyl group represented by R ⁴ or R ⁵ in the general formula (3).

In the present invention, as the metal complex represented by the general formula (1) having the general formula (2) or general formula ML ¹ represented by (3) as a partial structure, in particular, the following general formula (11) to The compound represented by the general formula (16) is preferable.

The general formula (11) to the general formula (16), ^{R 4} and ^{R 5,} the general formula (2) and (3) have the same meanings as ^{R 4} and ^{R 5} in each represent a hydrogen atom or a substituent , R ⁴ and R ⁵ represent an acyclic alkyl group having 5 to 20 carbon atoms which may have a substituent.

  Specific examples of the acyclic alkyl group include r0501 to r2002 exemplified above.

Further, in L ^{1 to} L ³ represented by the general formula (1) according to the present invention, ML ¹ is a partial structure represented by the general formula (2), and L ^{1 to} L ³ are Although they may be the same and may be the same or different, when L ² and L ³ and L ¹ have different structures, ML ² and ML ³ are represented by the following general formula (21) to It is preferably selected from the structure represented by the general formula (26).

  In the general formulas (21) to (26), R ′ and R ″ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an amino group, an alkenyl group, an aryl group or a heteroaryl group. X represents a sulfur atom, NZ, oxygen atom, selenium atom, BZ, CZZ ′ or C═O, wherein Z and Z ′ each independently represent a hydrogen atom, an alkyl group or an aryl group.

Moreover, it is preferable that the relationship between L ¹ and the chemical formula weight of L ² or L ³ (the sum of products of the atomic weight and the number of atoms) is L ¹ ≧ L ² and L ¹ ≧ L ³ .

In the general formula (1) according to the present invention, at least one of L ^{1 to} L ³ is connected via M, and further, L ¹ and L ² , L ² and L ³ , or L ¹ And L ³ are linked through a divalent linking group is one of the preferred embodiments, specifically represented by the following general formula (31) to general formula (32). A hexacoordinate metal complex is preferred.

In the general formula (31) to general formula (32), L ^{1 to} L ³ and M have the same meaning as those in the general formula (1).

In the general formula (31), V represents a trivalent linking group, and is covalently bonded to each of L ^{1 to} L ³ to form a hexadentate ligand. V is not particularly limited as long as it is a group linking each bidentate ligand, but the following structures are preferred. * Represents a bonding portion with L ^{1 to} L ^3, and n represents 1 or 2.

In the general formula (32), V ₁ and V ₂ each represent a divalent linking group, and L ¹ and L ² , and L ² and L ³ are each linked by a covalent bond to form a hexadentate ligand. To do. V ₁ and V ₂ are not particularly limited as long as they are groups linking each bidentate ligand, but linking groups having the following structures are preferred.

In the formula, R ′ represents a hydrogen atom or a substituent, and X represents a divalent aromatic group, an aromatic heterocyclic group, an oxygen atom, a sulfur atom, an optionally substituted nitrogen atom, CO, COO or Represents SO ₂ , 1 represents 0 or 1, and m and n each represents an integer of 1 to 12;

In the general formula (33), V ₁ represents a divalent linking group, and L ¹ and L ² are linked by a covalent bond to form a tetradentate ligand. V ₁ is not particularly limited as long as it is a group linking a bidentate ligand, but the linking group exemplified in the general formula (32) is preferable.

  Next, specific examples of the metal complex represented by the general formula (1) according to the present invention are shown, but the present invention is not limited to these exemplified compounds.

(1) Compound Represented by General Formula (11) As specific examples of the compound represented by General Formula (11), Illustrative Compound D-101 to Illustrative Compound D-190 are shown.

Each number shown by abbreviations for R ⁴ and R ⁵ are the structure illustrated in the reduction 5 of 8.

(2) Compound Represented by General Formula (12) As specific examples of the compound represented by General Formula (12), Illustrative Compound D-191 to Illustrative Compound D-280 are shown.

Each number shown by abbreviations for R ⁴ and R ⁵ are the structure illustrated in the reduction 5 of 8.

(3) Compound represented by general formula (13) As specific examples of the compound represented by general formula (13), exemplary compound D-281 to exemplary compound D-360 are shown.

In addition, each number shown with the abbreviation about R ⁴ is the structure exemplified in Chemical Formula 5 to Chemical Formula 8.

(4) Compound Represented by General Formula (14) As specific examples of the compound represented by General Formula (14), Illustrative Compound D-361 to Illustrative Compound D-440 are shown.

Each number shown by abbreviations for R ⁴ and R ⁵ are the structure illustrated in the reduction 5 of 8.

(5) Compound represented by general formula (15) As specific examples of the compound represented by general formula (15), exemplary compound D-441 to exemplary compound D-520 are shown.

Each number shown by abbreviations for R ⁴ and R ⁵ are the structure illustrated in the reduction 5 of 8.

(6) Compound Represented by General Formula (16) As specific examples of the compound represented by General Formula (16), Illustrative Compound D-521 to Illustrative Compound D-600 are shown.

In addition, each number shown with the abbreviation about R ⁴ is the structure exemplified in Chemical Formula 5 to Chemical Formula 8.

  (7) Except for the compounds represented by general formula (12) to general formula (16), as specific examples of the metal complex represented by general formula (1), exemplified compound D-601 to exemplified compound D-640 It is shown below.

(8) Hexacoordinate metal complex represented by general formula (31) to general formula (32) As specific examples of the hexacoordinate metal complex represented by general formula (31) to general formula (32), Compound D-641 to Exemplary Compound D-650 are shown below.

  (9) Exemplified compound D-651 to exemplified compound D-660 are shown below as compounds other than Ir in the metal complex represented by the general formula (1).

(10) Synthesis Example of Metal Complex Represented by General Formula (1) According to the Present Invention The metal complex represented by the general formula (1) according to the present invention can be synthesized by a known method. Reference can be made to the method described on page 75, line 1 to line 17, page 75 of Public Publication No. 2006/121811, according to the following scheme. The compound obtained according to the following method was confirmed to be Exemplified Compound D-103 by NMR spectrum and Mass spectrum.

  Moreover, each compound illustrated above by the metal complex represented by General formula (1) which concerns on this invention can also be obtained by the method similar to the synthesis | combining method of the said exemplary compound D-103.

<< Constituent layers of organic EL elements >>
Although the preferable specific example of the layer structure of the organic EL element of this invention 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 (vi) anode // hole transport layer / anode buffer layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (vii) anode / anode Buffer layer / hole transport layer / light emitting layer / electron transport layer / cathode buffer layer / cathode The organic layer as used in the organic EL device of the present invention refers to, for example, the light emitting layer, electron transport layer, hole transport layer in the above configuration, A hole blocking layer or the like corresponds to this.

In the present invention, at least one of the organic layers is at least a metal complex represented by the general formula (1), and ML ¹ which is one of the ligands constituting the metal complex is represented by the general formula (2). It contains the metal complex which is the partial structure represented. Further, the organic layer containing the metal complex represented by the general formula (1) according to the present invention is preferably a light emitting layer.

  The light emitting layer according to the present invention may form a light emitting layer unit by forming a unit. Further, a non-light emitting intermediate layer may be provided between the light emitting layers, and the intermediate layer may include a charge generation layer. The organic EL element of the present invention preferably emits white light and is preferably a lighting device using these.

  Hereinafter, each layer which comprises the organic EL element of this invention is demonstrated.

<Light emitting layer>
In the light emitting layer according to the present invention, it is preferable that the metal complex represented by the general formula (1) is contained, but together with the compound represented by the general formula (1) according to the present invention, Conventionally known host compounds and dopants can be used in combination as long as the intended effect is not impaired.

  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 be the interface between the light emitting layer and the adjacent layer.

  The total film thickness of the light emitting layer is not particularly limited, but from the viewpoint of improving the uniformity of the film, preventing unnecessary application of high voltage during light emission, and improving the stability of the emission color with respect to the drive current. It is preferable to adjust in the range of 2 nm to 5 μm, more preferably in the range of 2 to 200 nm, and particularly preferably in the range of 5 to 100 nm.

  For the production of the light emitting layer, the metal complex or host compound represented by the general formula (1) according to the present invention is used, for example, by vacuum deposition or wet coating (also referred to as wet process, for example, spin coating or casting. , Die coating method, blade coating method, roll coating method, ink jet method, printing method, spray coating method, curtain coating method, LB method (Langmuir-Blodgett method and the like)). It can be formed as a film. In the present invention, it is particularly preferable to form a light emitting layer by applying a wet coating method (wet process) from the viewpoint that the effects of the present invention can be exhibited.

[Luminescent dopant compound]
In the light emitting layer according to the present invention, it is preferable to use a metal complex (phosphorescent compound, phosphorescent dopant) represented by the general formula (1) according to the present invention.

  The phosphorescent dopant compound referred to in the present invention is a compound in which light emission from an excited triplet is observed, specifically, a compound that emits phosphorescence at room temperature (25 ° C.), and has a phosphorescence quantum yield of 25. Although it is defined as a compound of 0.01 or more at ° C., a preferable phosphorescence quantum yield is 0.1 or more.

  The phosphorescence quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of Experimental Chemistry Course 4 of the 4th edition. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence dopant according to the present invention achieves the phosphorescence quantum yield (0.01 or more) in any solvent. That's fine.

  There are two types of light emission of the phosphorescent dopant in principle. One is the recombination of carriers on the host compound to which carriers are transported to generate an excited state of the luminescent host compound, and this energy is used as the phosphorescent dopant. The energy transfer type in which light emission from the phosphorescent dopant is obtained by moving to the other, and the other is that the phosphorescent dopant becomes a carrier trap, carrier recombination occurs on the phosphorescent dopant, and light emission from the phosphorescent dopant compound occurs. In any case, the excited state energy of the phosphorescent dopant is required to be lower than the excited state energy of the host compound.

  As a light emitting dopant related to the organic EL device of the present invention, together with the metal complex represented by the general formula (1) according to the present invention, it is used in conventional organic EL devices within a range not impairing the intended effect of the present invention. Although a luminescent dopant can be used together and the specific example is given, this invention is not limited to these.

  In addition, metal complex compounds conventionally used in organic EL devices can be used together with the metal complex represented by the general formula (1) according to the present invention, and examples thereof include compounds described in the following patent publications. Can do.

  For example, International Publication No. 00/70655, JP 2002-280178, JP 2001-181616, JP 2002-280179, JP 2001-181617, JP 2002-280180, JP 2001-247859 A, JP 2002-299060 A, JP 2001-313178 A, JP 2002-302671 A, JP 2001-345183 A, JP 2002-324679 A, International Publication. No. 02/15645, JP 2002-332291 A, JP 2002-50484 A, JP 2002-332292 A, JP 2002-83684 A, JP 2002-540572 A, JP 2002-2002 A. No. 117978, Japanese Patent Application Laid-Open No. 2002-33858 JP, JP-A-2002-170684, JP-A-2002-352960, WO01 / 93642, JP-A-2002-50483, JP-A-2002-1000047, JP-A-2002-173684. JP-A-2002-359082, JP-A-2002-175484, JP-A-2002-363552, JP-A-2002-184582, JP-A-2003-7469, JP-A-2002-525808, JP 2003-7471, JP 2002-525833, JP 2003-31366, JP 2002-226495, JP 2002-234894, JP 2002-2335076, JP 2002 No. 2411751, JP 2001-319779 A. JP, 2001-319780, 2002-62824, 2002-100474, 2002-203679, 2002-343572, 2002-203678, etc. It is.

[Host compound]
In the light emitting layer which concerns on this invention, it is a preferable aspect to contain a host compound with the metal complex represented by General formula (1) which concerns on this invention.

  In the present invention, a host compound (also referred to as a light-emitting host) is a compound that is contained in a light-emitting layer, has a mass ratio of 20% or more in the layer, and emits phosphorescence at room temperature (25 ° C.). Is defined as a compound having a phosphorescence quantum yield of less than 0.1, and preferably a phosphorescence quantum yield of less than 0.01.

  There is no restriction | limiting in particular as a light emission host which can be used for this invention, The compound conventionally used with an organic EL element can be used. Typical compounds include those having a basic skeleton such as carbazole derivatives, triarylamine derivatives, aromatic derivatives, nitrogen-containing heterocyclic compounds, thiophene derivatives, furan derivatives, oligoarylene compounds, carboline derivatives and diazacarbazole. Derivatives (herein, diazacarbazole derivatives are those in which at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom) and the like.

  As a known light-emitting host that can be used in the present invention, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from being long-wavelength, and has a high Tg (glass transition temperature) is preferable.

  In the present invention, a conventionally known light emitting host may be used alone, or a plurality of types may be used in combination. By using a plurality of types of light-emitting hosts, the movement of charges can be adjusted, and the organic EL element can be made highly efficient.

  In addition, by using a plurality of ortho-metalated iridium complexes represented by the general formula (1) according to the present invention used as the phosphorescent dopant described above or a conventionally known compound, it becomes possible to mix different light emissions. Thus, an arbitrary emission color can be obtained.

  In addition, the light emitting host used in the present invention may be a low molecular compound, a high molecular compound having a repeating unit, or a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (polymerizable light emitting host). Of course, one or a plurality of such compounds may be used.

  Specific examples of known light-emitting hosts include compounds described in the following patent documents.

  JP-A-2001-257076, 2002-308855, 2001-313179, 2002-319491, 2001-357777, 2002-334786, 2002-8860, 2002-334787, 2002-15871, 2002-334788, 2002-43056, 2002-334789, 2002-75645, 2002-338579, 2002-105445 gazette, 2002-343568 gazette, 2002-141173 gazette, 2002-352957 gazette, 2002-203683 gazette, 2002-363227 gazette, 2002-231453 gazette, No. 003-3165, No. 2002-234888, No. 2003-27048, No. 2002-255934, No. 2002-286061, No. 2002-280183, No. 2002-299060, No. 2002. -302516, 2002-305083, 2002-305084, 2002-308837, and the like.

  Hereinafter, although the specific example of the light emission host applicable to the light emitting layer of the organic EL element of this invention is given, this invention is not limited to these.

  Furthermore, in the light emitting layer of the organic EL device of the present invention, a compound represented by the following general formula (A) is particularly preferable as a light emitting host.

  In the general formula (A), Xa represents an oxygen atom or a sulfur atom, Xb, Xc, Xd, and Xe each represents a hydrogen atom, a substituent, or a group represented by the following general formula (B), Xb , Xc, Xd, and Xe represent a group represented by the following general formula (B), and at least one of the groups represented by the general formula (B) represents that Ar is a carbazolyl group. Represent.

General formula (B)
Ar- _{(L 4)} n - *
In the general formula (B), L ₄ represents a divalent linking group derived from an aromatic hydrocarbon ring or an aromatic heterocyclic ring. n represents 0 or an integer of 1 to 3, and when n is 2 or more, the plurality of L ₄ may be the same or different. * Represents a linking site with the general formula (A). Ar represents a group represented by the following general formula (C).

In the above general formula (C), Xf represents N (R ″), an oxygen atom or a sulfur atom, and E _{1 to} E ₈ represent C (R ″ ₁ ) or a nitrogen atom. R ″ and R ″ ₁ each represent a hydrogen atom, a substituent, or a linking site with L ₄ . * Represents a linking site of the _{L 4.}

  In the compound represented by the general formula (A), preferably at least two of Xb, Xc, Xd, and Xe are represented by the general formula (B), and more preferably Xc is represented by the general formula (B). And Ar in the general formula (B) represents a carbazolyl group which may have a substituent.

  Specific examples of the compound represented by the general formula (A) that are preferably used as the host compound (also referred to as a light emitting host) of the light emitting layer in the organic EL device of the present invention are given below, but the present invention is not limited thereto. .

  In the organic EL device of the present invention, a compound represented by the following general formula (A ′) is also particularly preferably used as the light emitting host of the light emitting layer.

  In the general formula (A ′), Xa represents an oxygen atom or a sulfur atom, Xb and Xc each represents a substituent or a group represented by the general formula (B), and at least one of Xb and Xc Represents a group represented by the general formula (B), and in at least one of the groups represented by the general formula (B), Ar represents a carbazolyl group.

In the compound represented by the general formula (A ′), preferably at least one of Xb and Xc is represented by the general formula (B), and more preferably, Ar in the general formula (B) has a substituent. And a carbazolyl group linked to L ₄ at the N-position optionally having Ar in the general formula (B).

  The compound represented by the general formula (A ′) that is preferably used as the host compound (also referred to as a light-emitting host) of the light-emitting layer of the organic EL device of the present invention is specifically a specific example that is previously used as a light-emitting host. H-7, H-11, H-12, H-14, H-18, H-29, H-30, H-31, and H-32 may be mentioned, but the present invention is not limited thereto. .

《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 with a single layer or a plurality of layers.

  An electron transport material (including a hole blocking material and an electron injection material) used for the electron transport layer only needs to have a function of transmitting electrons injected from the cathode to the light emitting layer. Can be selected and used from conventionally known compounds.

  Examples of conventionally known materials used for the electron transport layer (hereinafter referred to as electron transport materials) include heterocyclic tetracarboxylic acid anhydrides such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, naphthalene perylene, And azacarbazole derivatives including carbodiimide, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, carboline derivatives, and the like.

  Here, the azacarbazole derivative refers to one in which one or more carbon atoms constituting the carbazole ring are replaced with nitrogen atoms.

  Furthermore, in the 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. It is also possible to use a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain.

  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), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga, or Pb can also be used as the electron transport material.

  In addition, metal-free or metal phthalocyanine, or those having a terminal substituted with an alkyl group or a sulfonic acid group can also be used as the electron transport material.

  Further, similarly to the hole injection layer and the hole transport layer, inorganic semiconductors such as n-type-Si and n-type-SiC can also be used as the electron transport material.

  The electron transport layer is made of an electron transport material such as a vacuum deposition method, a wet method (also referred to as a wet process, such as a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, an ink jet method, a printing method, or a spraying method. The film can be formed by a coating method, a curtain coating method, an LB method (such as Langmuir-Blodgett method)), etc. In particular, a wet coating method (wet process) ) To form an electron transport layer.

  Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, about 5-5000 nm, Preferably it is 5-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

  Further, an electron transport layer having a high n property doped with impurities can also be used. Examples thereof include JP-A-4-297076, JP-A-10-270172, JP-A-2000-196140, 2001-102175, J.A. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, at least one of the organic layers adjacent to the light emitting layer contains a fluorine atom-containing compound. In one embodiment, the electron transport layer is disposed at a position adjacent to the light emitting layer. Sometimes, an electron transport material containing a fluorine atom can be used as the electron transport material.

  Hereinafter, specific examples of conventionally known compounds (electron transport materials) that are preferably used for forming an electron transport layer in the organic EL device of the present invention will be given, but the present invention is not limited thereto.

《Hole transport layer》
The hole transport layer is made of a hole transport 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 has any 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.

  The above-mentioned materials can be used as the hole transport material, 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 also two of those described in US Pat. No. 5,061,569. Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-3086 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 8 are linked in a starburst type ( MTDATA) and the like.

  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.

  JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material as described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used. In the present invention, these materials are preferably used because a light-emitting element with higher efficiency can be obtained.

  The 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, a printing method including an ink jet method, or an LB method. In particular, it is preferable to form the hole transport layer by applying a wet coating method (wet process).

  Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5-200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

  Alternatively, a hole transport layer having a high p property doped with impurities can be used. Examples thereof include JP-A-4-297076, JP-A-2000-196140, 2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like.

  In the present invention, it is preferable to use a hole transport layer having such a high p property because a device with lower power consumption can be produced.

  In the hole transport layer according to the present invention, hole transport materials conventionally used in organic EL devices can be used.

<Blocking layer: hole blocking layer, electron blocking layer>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258, 11-204359, and “Organic EL elements and their forefront of industrialization” (issued by NTT, Inc. on November 30, 1998). There is a hole blocking (hole blocking) layer.

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

  Moreover, the structure of the above-mentioned electron transport layer can be used as a hole-blocking layer according to the present invention, if necessary.

  The hole blocking layer of the organic EL device of the present invention is preferably provided adjacent to the light emitting layer.

  Examples of the hole blocking material applicable to the present invention include carbazole derivatives and azacarbazole derivatives cited as conventionally known host compounds described in the light emitting layer (here, azacarbazole derivatives are carbon atoms constituting a carbazole ring) In which one or more of these are replaced by a nitrogen atom).

  In the present invention, when a plurality of light emitting layers having different light emission colors are provided, the light emitting layer having the shortest wavelength of light emission is preferably closest to the anode among all the light emitting layers. In this case, it is preferable to additionally provide a hole blocking layer between the shortest wave layer and the light emitting layer next to the anode next to the anode.

  Furthermore, it is preferable that 50% by mass or more of the compound contained in the hole blocking layer provided at the position has an ionization potential of 0.3 eV or more larger than the host compound of the shortest wave emitting layer.

  The ionization potential is defined by the energy required to emit electrons at the HOMO (highest occupied orbital) level of the compound to the vacuum level, and can be determined by, for example, the following method.

  (1) Keywords using Gaussian 98 (Gaussian 98, Revision A.11.4, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2002.), which is molecular orbital calculation software manufactured by Gaussian, USA. As a value (eV unit converted value) calculated by performing structure optimization using B3LYP / 6-31G *. This calculation value is effective because the correlation between the calculation value obtained by this method and the experimental value is high.

  (2) The ionization potential can also be obtained by a method of directly measuring by photoelectron spectroscopy. For example, a method known as ultraviolet photoelectron spectroscopy can be suitably used by using a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki Co., Ltd.

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

  Moreover, the structure of the above-mentioned hole transport layer can be used as an electron blocking layer as needed. The film thickness of the hole blocking layer and the electron blocking layer according to the present invention is preferably 3 to 100 nm, and more preferably 3 to 30 nm.

<< Injection layer: electron injection layer (cathode buffer 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, it 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. May be.

  An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166), 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 typified by, alkali metal compound buffer layer typified by lithium fluoride, sodium fluoride and potassium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, and aluminum oxide And an oxide buffer layer. The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

  In addition, the materials used for the anode buffer layer and the cathode buffer layer can be used in combination with other materials. For example, the materials can be mixed in the hole transport layer or the electron transport layer.

"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 composite oxide (hereinafter abbreviated as 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, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method. A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material.

  Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used.

  When light emission is extracted from the anode, it is desirable that the transmittance be 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 5 μm, preferably 50 to 200 nm.

  In order to transmit the emitted 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.

  Moreover, after producing the metal with a film thickness of 1 to 20 nm on the cathode, a transparent or translucent cathode can be produced by producing the conductive transparent material mentioned in the description of the anode on the cathode, By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

《Support substrate》
The support substrate (hereinafter also referred to as a substrate, substrate, substrate, support, etc.) that can be used in the organic EL device of the present invention is not particularly limited in the type of glass, plastic, etc., and is transparent. May be opaque. When extracting light from the support substrate side, the support substrate is preferably transparent.

  Examples of the transparent support substrate preferably used include glass, quartz, and a transparent resin film. A particularly preferable support substrate is a resin film capable of giving flexibility to the organic EL element.

  Examples of the resin film include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyethylene, polypropylene, cellophane, cellulose diacetate, cellulose triacetate (TAC), cellulose acetate butyrate, cellulose acetate propionate ( CAP), cellulose esters such as cellulose acetate phthalate, cellulose nitrate or derivatives thereof, polyvinylidene chloride, polyvinyl alcohol, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide , Polyethersulfone (PES), polyphenylene sulfide, polysulfones, Cycloolefin resins such as polyetherimide, polyetherketoneimide, polyamide, fluororesin, nylon, polymethylmethacrylate, acrylic or polyarylate, Arton (trade name, manufactured by JSR) or Appel (trade name, manufactured by Mitsui Chemicals) Can be mentioned.

An inorganic film, an organic film, or a hybrid film of both may be formed on the surface of the resin film, and the water vapor permeability (25 ± 0.5 ° C.) measured by a method according to JIS K 7129-1992. , Relative humidity (90 ± 2)% RH) is preferably 0.01 g / (m ² · 24h · atm) or less, and further measured by a method according to JIS K 7126-1987. The film has a high barrier property with an oxygen permeability of 1 × 10 ⁻³ ml / (m ² · 24 h · atm) or less and a water vapor permeability of 1 × 10 ⁻⁵ g / (m ² · 24 h · atm) or less. Is preferred.

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing entry of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like can be used. Further, in order to improve the brittleness of the film, it is more preferable to have a laminated structure of these inorganic layers and organic material layers. Although there is no restriction | limiting in particular about the lamination | stacking order of an inorganic layer and an organic layer, It is preferable to laminate | stack both alternately several times.

  The method for forming the barrier film is not particularly limited. For example, the vacuum deposition method, sputtering method, reactive sputtering method, molecular beam epitaxy method, cluster ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma weight A combination method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, and the like can be used, but an atmospheric pressure plasma polymerization method as described in JP-A-2004-68143 is particularly preferable.

  Examples of the opaque support substrate include metal plates such as aluminum and stainless steel, films, opaque resin substrates, and ceramic substrates.

  The external extraction efficiency at room temperature of light emission of the organic EL device of the present invention is preferably 1% or more, more preferably 5% 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.

  In addition, a hue improvement filter such as a color filter may be used in combination, or a color conversion filter that converts the emission color from the organic EL element into multiple colors using a phosphor may be used in combination. In the case of using a color conversion filter, the λmax of light emission of the organic EL element is preferably 480 nm or less.

<< Method for Manufacturing Organic EL Element >>
As an example of a method for producing an organic EL device, a device comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer 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 so as to have a thickness of 1 μm or less, preferably 10 to 200 nm, and an anode is manufactured.

  Next, a thin film containing an organic compound such as a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron transport layer, or a cathode buffer layer, which is an element material, is formed thereon.

  In the organic EL device of the present invention, it is preferable that at least the cathode and the electron transport layer adjacent to the cathode are coated and formed by a wet coating method.

  Wet methods include spin coating, casting, die coating, blade coating, roll coating, ink jet, printing, spray coating, curtain coating, and LB, but precise thin films can be formed. From the viewpoint of high productivity, a method having high suitability for a roll-to-roll method such as a die coating method, a roll coating method, an ink jet method, or a spray coating method is preferable. Different film forming methods may be applied for each layer.

  Examples of the liquid medium for dissolving or dispersing the organic EL material according to the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, and mesitylene. Aromatic hydrocarbons such as cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, and organic solvents such as N, N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) can be used.

  Moreover, as a dispersion method, it can disperse | distribute by dispersion methods, such as ultrasonic dispersion, high shear force dispersion | distribution, and media dispersion | distribution.

  After the formation of these layers, a thin film made of a cathode material is formed thereon so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and provided as a cathode, thereby obtaining a desired organic EL device. .

  Further, the order can be reversed, and the cathode, cathode buffer layer, electron transport layer, hole blocking layer, light emitting layer, hole transport layer, hole injection layer, and anode can be formed 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. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

  The organic EL device of the present invention 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 preferable to perform the work in a dry inert gas atmosphere.

<Sealing>
As a sealing means used for this invention, the method of adhere | attaching a sealing member, an electrode, and a support substrate with an adhesive agent can be mentioned, for example.

  As a sealing member, it should just be arrange | positioned so that the display area | region of an organic EL element may be covered, and concave plate shape or flat plate shape may be sufficient. Further, transparency and electrical insulation are not particularly limited.

  Specific examples include a glass plate, a polymer plate / film, and a metal plate / film. Examples of the glass plate include soda-lime glass, barium / strontium-containing glass, lead glass, aluminosilicate glass, borosilicate glass, barium borosilicate glass, and quartz.

  Examples of the polymer plate include polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, and polysulfone. Examples of the metal plate include those made of one or more metals or alloys selected from the group consisting of stainless steel, iron, copper, aluminum, magnesium, nickel, zinc, chromium, titanium, molybdenum, silicon, germanium, and tantalum.

  In the present invention, a polymer film and a metal film can be preferably used because the element can be thinned.

Furthermore, the polymer film has a oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ ml / (m ² · 24 h · MPa) or less, and a method according to JIS K 7129-1992. It is preferable that the water vapor permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured in (1) is 1 × 10 ⁻³ g / (m ² · 24 h) or less.

  For processing the sealing member into a concave shape, sandblasting, chemical etching, or the like is used.

  Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups such as acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to. Moreover, heat | fever and chemical curing types (two-component mixing), such as an epoxy type, can be mentioned. Moreover, hot-melt type polyamide, polyester, and polyolefin can be mentioned. Moreover, a cationic curing type ultraviolet curing epoxy resin adhesive can be mentioned.

  In addition, since an organic EL element may deteriorate by heat processing, what can be adhesive-hardened from room temperature to 80 degreeC is preferable. A desiccant may be dispersed in the adhesive. Application | coating of the adhesive agent to a sealing part may use commercially available dispenser, and may print like screen printing.

  In addition, it is also preferable that the electrode and the organic layer are coated on the outside of the electrode facing the support substrate with the organic layer interposed therebetween, and an inorganic or organic layer is formed in contact with the support substrate to form a sealing film. . In this case, the material for forming the film may be any material that has a function of suppressing intrusion of elements that cause deterioration of elements such as moisture and oxygen. For example, silicon oxide, silicon dioxide, silicon nitride, or the like may be used. it can.

  Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials.

  The method for forming these films is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster-ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

  In the gap between the sealing member and the display area of the organic EL element, an inert gas such as nitrogen or argon, or an inert liquid such as fluorinated hydrocarbon or silicon oil can be injected in the gas phase and liquid phase. preferable. A vacuum is also possible. Moreover, a hygroscopic compound can also be enclosed inside.

  Examples of the hygroscopic compound include metal oxides (for example, sodium oxide, potassium oxide, calcium oxide, barium oxide, magnesium oxide, aluminum oxide) and sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, cobalt sulfate). Etc.), metal halides (eg calcium chloride, magnesium chloride, cesium fluoride, tantalum fluoride, cerium bromide, magnesium bromide, barium iodide, magnesium iodide etc.), perchloric acids (eg perchloric acid) Barium, magnesium perchlorate, etc.), among others, anhydrous salts are preferably used in sulfates, metal halides and perchloric acids.

《Protective film, protective plate》
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film. In particular, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high, and thus it is preferable to provide such a protective film and a protective plate. As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, and the like used for the sealing can be used, but the polymer film is light and thin. Is preferably used.

《Light extraction》
The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1) and can extract only about 15% to 20% of the light generated in the light emitting layer. It is generally said. This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the element side surface.

  As a method for improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate to prevent total reflection at the interface between the transparent substrate and the air (US Pat. No. 4,774,435), A method of improving efficiency by providing a light collecting property to a substrate (Japanese Patent Laid-Open No. 63-314795), a method of forming a reflective surface on a side surface of an element (Japanese Patent Laid-Open No. 1-220394), and light emission from a substrate A method of forming an antireflection film by introducing a flat layer having an intermediate refractive index between the bodies (Japanese Patent Laid-Open No. 62-172691), a flat having a lower refractive index between the substrate and the light emitter than the substrate A method of introducing a layer (Japanese Patent Laid-Open No. 2001-202827), a method of forming a diffraction grating between any one of a substrate, a transparent electrode layer and a light emitting layer (including between the substrate and the outside) (Japanese Patent Laid-Open No. 11-283951) Gazette).

  In the present invention, these methods can be used in combination with the organic EL device of the present invention. However, a method of introducing a flat layer having a lower refractive index than the substrate between the substrate and the light emitter, or a substrate, transparent A method of forming a diffraction grating between any layers of the electrode layer and the light emitting layer (including between the substrate and the outside) can be suitably used.

  In the present invention, by combining these means, it is possible to obtain an element having higher luminance or durability.

  When a medium with a low refractive index is formed between the transparent electrode and the transparent substrate with a thickness longer than the wavelength of light, the light extracted from the transparent electrode has a higher extraction efficiency to the outside as the refractive index of the medium is lower. .

  Examples of the low refractive index layer include aerogel, porous silica, magnesium fluoride, and a fluorine-based polymer. Since the refractive index of the transparent substrate is generally about 1.5 to 1.7 as measured at room temperature, the low refractive index layer preferably has a refractive index of about 1.5 or less. Further, it is preferably 1.35 or less.

  The thickness of the low refractive index medium is preferably at least twice the wavelength in the medium. This is because the effect of the low refractive index layer is diminished when the thickness of the low refractive index medium is about the wavelength of light and the electromagnetic wave that has exuded by evanescent enters the substrate.

  The method of introducing a diffraction grating into an interface or any medium that causes total reflection is characterized by a high effect of improving light extraction efficiency. This method uses the property that the diffraction grating can change the direction of light to a specific direction different from refraction by so-called Bragg diffraction such as first-order diffraction and second-order diffraction. Light that cannot be emitted due to total internal reflection between layers is diffracted by introducing a diffraction grating in any layer or medium (in a transparent substrate or transparent electrode), and the light is removed. I want to take it out.

  The introduced diffraction grating desirably has a two-dimensional periodic refractive index. This is because light emitted from the light-emitting layer is randomly generated in all directions, so in a general one-dimensional diffraction grating having a periodic refractive index distribution only in a certain direction, only light traveling in a specific direction is diffracted. Therefore, the light extraction efficiency does not increase so much.

  However, by making the refractive index distribution a two-dimensional distribution, light traveling in all directions is diffracted, and light extraction efficiency is increased.

  As described above, the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or the transparent electrode), but is preferably in the vicinity of the organic light emitting layer where light is generated.

  At this time, the period of the diffraction grating is preferably about 1/2 to 3 times the wavelength of light in the medium.

  The arrangement of the diffraction grating is preferably two-dimensionally repeated such as a square lattice, a triangular lattice, or a honeycomb lattice.

<Condenser sheet>
The organic EL element of the present invention is processed to provide, for example, a microlens array-like structure on the light extraction side of the substrate, or in combination with a so-called condensing sheet, so that the organic EL element is in front of the element light emitting surface. By condensing in the direction, the luminance in a specific direction can be increased.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are arranged two-dimensionally on the light extraction side of the substrate. One side is preferably 10 to 100 μm. If it becomes smaller than this, the effect of diffraction will generate | occur | produce and color, and if too large, thickness will become thick and is not preferable.

  As the condensing sheet, for example, a sheet that is put into practical use in an LED backlight of a liquid crystal display device can be used. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used.

  As the shape of the prism sheet, for example, the base material may be formed by forming a △ -shaped stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

  Moreover, in order to control the light emission angle from a light emitting element, you may use together a light diffusing plate and a film with a condensing sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

<Application>
The organic EL element of the present invention can be used as a display device, a display, and various light emission sources. For example, lighting devices (home lighting, interior lighting), clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources of optical storage media, light sources of electrophotographic copying machines, light sources of optical communication processors, light Although the light source of a sensor etc. are mentioned, It is not limited to this, Especially, it can use effectively for the use as a backlight of a liquid crystal display device, and a light source for illumination.

  In the organic EL element of the present invention, patterning may be performed by a metal mask, an ink jet printing method, or the like as needed during film formation. In the case of patterning, only the electrode may be patterned, the electrode and the light emitting layer may be patterned, or the entire layer of the element may be patterned. In the fabrication of the element, a conventionally known method is used. Can do.

  The light emission color of the organic EL device of the present invention and the compound according to the present invention is shown in FIG. 4.16 on page 108 of “New Color Science Handbook” (edited by the Japan Color Society, University of Tokyo Press, 1985). It is determined by the color when the result measured with a total CS-1000 (Konica Minolta Sensing Co., Ltd.) is applied to the CIE chromaticity coordinates.

When the organic EL element of the present invention is a white element, white means that the chromaticity in the CIE1931 color system at 1000 cd / m ² is X when the 2 ° viewing angle front luminance is measured by the above method. = 0.33 ± 0.07 and Y = 0.33 ± 0.1.

<Display device>
The display device of the present invention will be described. The display device of the present invention comprises the organic EL element of the present invention.

  Although the display device of the present invention may be single color or multicolor, the multicolor display device will be described here. In the case of a multicolor display device, a shadow mask is provided only at the time of forming a light emitting layer, and a film can be formed on one surface by vapor deposition, casting, spin coating, ink jet, printing, or the like.

  In the case of patterning only the light emitting layer, the method is not limited. However, the vapor deposition method, the ink jet method, the spin coating method, and the printing method are preferable.

  The configuration of the organic EL element provided in the display device is selected from the above-described configuration examples of the organic EL element as necessary.

  Moreover, the manufacturing method of an organic EL element is as having shown to the one aspect | mode of manufacture of the organic EL element of said invention.

  When a DC voltage is applied to the obtained multicolor display device, light emission can be observed by applying a voltage of about 2V to 40V with the anode as + and the cathode as-polarity. 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 can be used as a display device, a display, and various light emission sources. In a display device or 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 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. The present invention is not limited to these examples.

  Hereinafter, an example of a display device having the organic EL element of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic view showing an example of a display device composed of 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 a plurality of pixels based on image information from the outside, and the pixels for each scanning line respond to the image data signal by the scanning signal. The image information 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.

  In the drawing, the light L emitted from the pixel 3 is extracted in the direction of the white arrow (downward).

  The scanning line 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 grid pattern and are connected to the pixels 3 at the orthogonal positions (details are illustrated). Not)

  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 on the same substrate.

《Lighting device》
The lighting device of the present invention will be described. The illuminating device of this invention has the said organic EL element.

  The organic EL element of the present invention may be used as an organic EL element having a resonator structure. The purpose of use of the organic EL element having such a resonator structure is as follows. The light source of a machine, the light source of an optical communication processing machine, the light source of a photosensor, etc. are mentioned, However It is not limited to these. Moreover, you may use for the said use by making a laser oscillation.

  Further, the organic EL element of the present invention may be used as a kind of lamp for illumination or exposure light source, a projection device for projecting an image, or a display for directly viewing a still image or a moving image. It may be used as a device (display).

  The driving method when used as a display device for moving image reproduction may be either a simple matrix (passive matrix) method or an active matrix method. Alternatively, it is possible to produce a full-color display device by using two or more organic EL elements of the present invention having different emission colors.

  The organic EL material of the present invention can be applied to an organic EL element that emits substantially white light as a lighting device. A plurality of light emitting colors are simultaneously emitted by a plurality of light emitting materials to obtain white light emission by color mixing. The combination of a plurality of emission colors may include three emission maximum wavelengths of the three primary colors of blue, green, and blue, or two using the relationship of complementary colors such as blue and yellow, blue green and orange, etc. The thing containing the light emission maximum wavelength may be used.

  In addition, a combination of light emitting materials for obtaining a plurality of emission colors is a combination of a plurality of phosphorescent or fluorescent materials, a light emitting material that emits fluorescence or phosphorescence, and light from the light emitting material as excitation light. Any of those combined with a dye material that emits light may be used, but in the white organic EL device according to the present invention, only a combination of a plurality of light-emitting dopants may be mixed.

  It is only necessary to provide a mask only when forming a light emitting layer, a hole transport layer, an electron transport layer, etc., and simply arrange them separately by coating with the mask. Since other layers are common, patterning of the mask or the like is not necessary. In addition, for example, an electrode film can be formed by a vapor deposition method, a cast method, a spin coating method, an ink jet method, a printing method, or the like, and productivity is also improved.

  According to this method, unlike a white organic EL device in which light emitting elements of a plurality of colors are arranged in parallel in an array, the elements themselves are luminescent white.

  There is no restriction | limiting in particular as a luminescent material used for a light emitting layer, For example, if it is a backlight in a liquid crystal display element, the metal complex which concerns on this invention so that it may suit the wavelength range corresponding to CF (color filter) characteristic, Any one of known luminescent materials may be selected and combined to whiten.

<< One Embodiment of Lighting Device of the Present Invention >>
One aspect of the lighting device of the present invention that includes the organic EL element of the present invention will be described.

  The non-light emitting surface of the organic EL device of the present invention is covered with a glass case, a glass substrate having a thickness of 300 μm is used as a sealing substrate, and an epoxy-based photocurable adhesive (LUX TRACK manufactured by Toagosei Co., Ltd.) is used as a sealing material. LC0629B) is applied, and this is overlaid on the cathode to be in close contact with the transparent support substrate, irradiated with UV light from the glass substrate side, cured and sealed, and as shown in FIG. 3 and FIG. Can be formed.

  FIG. 3 is a schematic view of the lighting device, and the organic EL element 101 of the present invention is covered with a glass cover 102. The sealing operation with the glass cover is performed in a glove box (in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more) in a nitrogen atmosphere without bringing the organic EL element 101 into contact with the atmosphere.

  4 shows a cross-sectional view of the lighting device. In FIG. 4, reference numeral 105 denotes a cathode, 106 denotes an organic EL layer, and 107 denotes a glass substrate with a transparent electrode. The glass cover 102 is filled with nitrogen gas 108 and a water catching agent 109 is provided.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "%" is used in an Example, unless otherwise indicated, "mass%" is represented.

  First, the structures of compounds other than those exemplified in the examples described below are shown.

Example 1
<< Production of organic EL element >>
[Production of Organic EL Element 1-1]
After patterning an indium-tin composite oxide (ITO) with a thickness of 100 nm on a 100 mm × 100 mm × 1.1 mm glass substrate (NA Techno Glass NA45), this ITO The transparent support substrate provided with the transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes to form an anode.

  On this transparent support substrate, using a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water, 3000 rpm, A thin film was formed by spin coating under conditions of 30 seconds and then dried at 200 ° C. for 1 hour to form a first hole transport layer having a thickness of 20 nm.

  Next, the transparent support substrate provided with the first hole transport layer was fixed to a substrate holder of a commercially available vacuum deposition apparatus. On the other hand, 200 mg of α-NPD (hole transport material) is put in a molybdenum resistance heating boat, 200 mg of CBP (host compound) is put in another molybdenum resistance heating boat, and another molybdenum resistance heating boat is used as a dopant compound. 200 mg of Exemplified Compound D-9 was placed, 200 mg of BCP (electron transport material) was placed in another molybdenum resistance heating boat, and each was attached to a vacuum deposition apparatus.

Next, after reducing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing α-NPD was energized and heated, and deposited on the hole injection layer at a deposition rate of 0.1 nm / second. A 30 nm hole transport layer was provided.

  Furthermore, the hole-transporting layer is heated at a deposition rate of 0.1 nm / second and 0.010 nm / second respectively by energizing and heating the heating boat containing CBP and the heating boat containing Exemplary Compound D-9. Co-evaporated on top to form a 40 nm thick light emitting layer.

  Next, the heating boat containing BCP was further energized and heated, and deposited on the hole blocking layer at a deposition rate of 0.1 nm / second to form an electron transport layer having a thickness of 30 nm.

  Subsequently, lithium fluoride was vapor-deposited as a cathode buffer layer with a thickness of 0.5 nm, and an aluminum thin film was vapor-deposited with a thickness of 110 nm to form a cathode, whereby an organic EL element 1-1 was produced.

[Production of Organic EL Elements 1-2 to 1-563]
In preparation of the said organic EL element 1-1, except having changed the exemplary compound D-9 which is a dopant compound used by formation of the light emitting layer into each dopant compound of Table 1-Table 12, it is organic similarly. EL elements 1-2 to 1-563 were produced.

<< Evaluation of organic EL elements >>
[Production of lighting device]
The non-light emitting surface of the produced organic EL elements 1-1 to 1-563 is covered with a glass cover, and an epoxy system is used as a sealant around the glass cover side where the glass cover and the glass substrate on which the organic EL element is produced are in contact. Using a photo-curing adhesive (Luxtrac LC0629B, manufactured by Toagosei Co., Ltd.), this is superimposed on the cathode side of the organic EL element and adhered to the transparent support substrate, and the organic EL element is removed from the glass substrate side. Illumination devices 1-1 to 1-563 having the configurations shown in FIGS. 3 and 4 were manufactured by being cured by irradiation with UV light.

[Evaluation of lighting equipment]
The following evaluations were performed on each of the manufactured illumination devices.

(1) Evaluation of external extraction quantum efficiency Each organic EL element constituting each lighting device emits light under a constant current condition of ^2.5 mA / cm ² in an environment of 23 ° C. and 50% RH, and immediately after the start of light emission. The external extraction quantum efficiency (η) was calculated by measuring the light emission luminance L (cd / m ² ). The emission luminance L was measured using CS-1000 (manufactured by Konica Minolta Optics), and the external extraction quantum efficiency was expressed as a relative value with the emission luminance L of the organic EL element 1-1 being 100. It represents that it is excellent in external extraction quantum efficiency, so that a numerical value is large.

(2) Evaluation of half-life Each organic EL element constituting each lighting device is continuously driven at a constant current at a current giving an initial luminance of 1000 cd / m ² in an environment of 23 ° C. and 50% RH, and the initial luminance Time (half-life: τ _1/2 ) until ½ (500 cd / m ² ) was obtained, and this half-life τ _1/2 was used as a measure of half-life.

In addition, evaluation of half-life was represented by the relative value which sets the half-life (tau) _1/2 of the organic EL element 1-1 to 100. The larger the value, the longer the light emission lifetime.

(3) Evaluation of driving voltage: resistance to increase in driving voltage Each organic EL element constituting each lighting device emits light under a constant current condition of ^2.5 mA / cm ² in an environment of 23 ° C. and 50% RH. Then, after measuring the voltage (V ₁ ) at the start of driving, in the same way as the evaluation of the half life described above, the time until the brightness reaches half (500 cd / m ² ) of the initial luminance (half life: τ _1/2 ) Was measured, and the drive voltage (V ₂ ) at this time was measured, and the drive voltage increase ΔV was measured according to the following equation.

Driving voltage increase degree ΔV = drive voltage V ₂ at half brightness−initial drive voltage V ₁
In addition, evaluation of the drive voltage was represented by the relative value which sets 100 as the raise degree (DELTA) V of the drive voltage of the organic EL element 1-1. A smaller value indicates a smaller voltage increase during driving.

(4) Thermal Stability Evaluation In the production of the organic EL elements 1-1 to 1-563, the dopant compound is added to a molybdenum resistance heating boat, and the amount necessary to produce the light emitting layer of the organic EL element 10 times. 10 organic EL elements were continuously manufactured while being loaded and heated in the same heating boat (for example, for the organic EL element 1-1, the organic EL elements 1-1-1, 1-1-2, 1 -1-3, ..., 1-1-10 were produced.). In addition, about formation materials other than a dopant compound, whenever it produced each organic EL element, it replaced | exchanged for the new material.

  The organic EL element (for example, organic EL element 1-1-1) produced for the first time of each organic EL element, and the organic EL element (for example, organic EL element) produced using the dopant compound that has undergone the third deposition process. 1-1-3) The half-life was measured by the same method as described above for each of the organic EL elements (for example, the organic EL element 1-1-10) prepared using the dopant compound that had undergone the tenth vapor deposition treatment. .

Evaluation of the thermal stability of each organic EL element is halved for each organic EL element (for example, organic EL element 1-1-1, organic EL element 1-2-1 etc.) prepared for the first time of the organic EL element. The lifetime (half-life: τ _1/2 ) is set to 100, and the relative half-life of the organic EL elements (for example, the organic EL element 1-1-3, the organic EL element 1-2-3, etc.) prepared for the third time, And the relative half life of the element (for example, organic EL element 1-1-10, organic EL element 1-2-10 etc.) produced for the 10th time was computed. The closer the value is to 100, the better the thermal stability of the dopant compound when the light emitting layer of the organic EL element is continuously formed.

  The results obtained as described above are shown in Tables 1 to 12.

  As is clear from the results shown in Tables 1 to 12, the organic EL elements 1-4 to 1-563 of the present invention emit higher light than the organic EL elements 1-1 to 1-3 of the comparative example. It can be seen that the characteristics as an organic EL element are improved, such as efficiency and long life, and suppression of voltage increase during driving. Furthermore, in the organic EL elements 1-1 to 1-3 of the comparative example, the half life (relative value) of the organic EL element produced for the third time, with respect to the half life of the organic EL element produced for the first time, While the half-life (relative value) of the organic element produced for the 10th time is greatly reduced, the organic EL elements 1-4 to 1-563 of the present invention are those of the organic EL element produced for the first time. The reduction rate of the half-life of the organic EL element produced using the dopant compound that has been subjected to the third vapor deposition treatment and the dopant compound that has been subjected to the tenth vapor deposition treatment, relative to the half-life. It is found that the dopant compound used in the organic EL device of the present invention is excellent in thermal stability when it is extremely small and continuously produced.

Example 2
<< Production of organic EL element >>
[Production of Organic EL Element 2-1]
Patterning was performed on a substrate (NA45 manufactured by NH Techno Glass Co., Ltd.) in which a composite oxide of indium-tin (hereinafter abbreviated as ITO) was formed on a 100 mm × 100 mm × 1.1 mm glass substrate with a thickness of 100 nm. Thereafter, the transparent support substrate provided with the ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes to form an anode.

  On this transparent support substrate, using a solution obtained by diluting poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) to 70% with pure water, 3000 rpm, A thin film was formed by spin coating under conditions of 30 seconds, and then dried at 200 ° C. for 1 hour to provide a first hole transport layer having a thickness of 20 nm.

  Next, the transparent support substrate provided with the first hole transport layer was transferred to a nitrogen atmosphere, and 50 mg of ADS254BE (American Dye Source, Inc. hole transport material, Poly, on the formed first hole transport layer). [N, N-bis (4-butylphenyl) -N, N-bis (phenyl) -benzidine]) was dissolved in 10 ml of monochlorobenzene at 2500 rpm for 30 seconds using a spin coating method. Formed. Furthermore, it vacuum-dried at 130 degreeC for 1 hour, and the 2nd positive hole transport layer was formed.

  On this 2nd hole transport layer, spin coat method was carried out on the conditions of 1000 rpm and 30 seconds using the solution which melt | dissolved 100 mg CBP (above) and 13 mg exemplary compound D-9 in 10 ml butyl acetate. A thin film was formed. Furthermore, it vacuum-dried at 60 degreeC for 1 hour, and formed the light emitting layer about 45 nm thick.

  Next, a thin film was formed on this light emitting layer by spin coating using a solution obtained by dissolving 50 mg of BCP (supra) in 10 ml of hexafluoroisopropanol (HFIP) at 1000 rpm for 30 seconds. Furthermore, it vacuum-dried at 60 degreeC for 1 hour, and formed the electron carrying layer about 25 nm thick.

Next, this substrate is fixed to a substrate holder of a vacuum deposition apparatus, the vacuum chamber is decompressed to 4 × 10 ⁻⁴ Pa, potassium fluoride is deposited as a cathode buffer layer with a thickness of 0.4 nm, and an aluminum thin film is further formed. A cathode was formed by vapor deposition at a thickness of 110 nm to prepare an organic EL element 2-1.

[Production of Organic EL Elements 2-2 to 2-563]
In the production of the organic EL device 2-1, organic compound D-9, which is the dopant compound used in forming the light emitting layer, was changed to the respective dopant compounds shown in Tables 13 to 24 in the same manner. EL elements 2-2 to 2-563 were produced.

<< Evaluation of organic EL elements >>
[Production of lighting device]
The non-light emitting surface of the produced organic EL elements 2-1 to 2-563 is covered with a glass cover, and an epoxy system is used as a sealant around the glass cover side where the glass cover and the glass substrate on which the organic EL elements are produced are in contact. Using a photo-curing adhesive (Luxtrac LC0629B, manufactured by Toagosei Co., Ltd.), this is superimposed on the cathode side of the organic EL element and adhered to the transparent support substrate, and the organic EL element is removed from the glass substrate side. Illumination devices 2-1 to 2-563 having the configuration shown in FIGS. 3 and 4 were produced by curing by UV irradiation and curing.

[Evaluation of lighting equipment]
For each of the manufactured lighting devices, in the same manner as described in Example 1, the external extraction quantum efficiency is evaluated, the half-life is evaluated, and the driving voltage is evaluated (driving voltage rise resistance). Tables 13 to 24 show. In addition, in each said evaluation, it represented with the relative value which sets the measured value of the organic EL element 2-1 to 100.

  As is clear from the results shown in Tables 13 to 24, the organic EL elements 2-4 to 2-563 of the present invention emit higher light than the organic EL elements 2-1 to 2-3 of the comparative examples. It can be seen that the characteristics as an organic EL element are improved, such as efficiency and long life, and suppression of voltage increase during driving.

Example 3
<< Production of organic EL element >>
[Production of Organic EL Element 3-1]
Patterning was performed on a substrate (NA45 manufactured by NH Techno Glass Co., Ltd.) in which a composite oxide of indium-tin (hereinafter abbreviated as ITO) was formed on a 100 mm × 100 mm × 1.1 mm glass substrate with a thickness of 100 nm. Thereafter, the transparent support substrate provided with the ITO transparent electrode was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes to form an anode.

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, 200 mg of TPD (hole transport material) is put into a molybdenum resistance heating boat, and 200 mg of CBP is put into another molybdenum resistance heating boat. 200 mg of Exemplified Compound D-9 is added as a dopant compound to a molybdenum resistance heating boat, 200 mg of Exemplified Compound D-1 is added as a dopant compound to another molybdenum resistance heating boat, and the dopant is added to another molybdenum resistance heating boat. 200 mg of Exemplified Compound D-6 was added as a compound, and 200 mg of BCP was charged as an electron transport material in another molybdenum resistance heating boat, and attached to a vacuum deposition apparatus.

Next, after the pressure in the vacuum chamber was reduced to 4 × 10 ⁻⁴ Pa, the heating boat containing TPD was heated by energization, and was deposited on the transparent support substrate at a deposition rate of 0.1 nm / second. The hole transport layer was formed.

  Subsequently, each heating boat containing CBP, Exemplified Compound D-9, Exemplified Compound D-1 and Exemplified Compound D-6 was energized and heated, and the deposition rates were 0.1 nm / sec, 0.025 nm / sec, A light emitting layer having a thickness of 60 nm was formed by co-evaporation on the hole transport layer at 0.0007 nm / second and 0.0002 nm / second.

  Furthermore, the heating boat containing BCP was energized and heated, and deposited on the light emitting layer at a deposition rate of 0.1 nm / second to form an electron transport layer having a thickness of 20 nm.

  Subsequently, potassium fluoride was vapor-deposited as a cathode buffer layer at a thickness of 0.5 nm, and an aluminum thin film was vapor-deposited at a thickness of 110 nm to form a cathode, thereby producing a white light-emitting organic EL device 3-1.

[Production of Organic EL Elements 3-2 to 3-563]
Except having changed example compound D-9 which is a blue luminescent dopant compound used by formation of a luminescent layer in preparation of the above-mentioned organic EL element 3-1, to each blue luminescent dopant compound of Table 25-Table 36. Produced white light emitting organic EL elements 3-2 to 3-563 in the same manner.

<< Evaluation of organic EL elements >>
[Production of lighting device]
The non-light emitting surface of the produced organic EL elements 3-1 to 3-563 is covered with a glass cover, and an epoxy system is used as a sealant around the glass cover side where the glass cover and the glass substrate on which the organic EL elements are produced are in contact. Using a photo-curing adhesive (Luxtrac LC0629B, manufactured by Toagosei Co., Ltd.), this is superimposed on the cathode side of the organic EL element and adhered to the transparent support substrate, and the organic EL element is removed from the glass substrate side. Illumination devices 3-1 to 3-563 having the configuration shown in FIGS. 3 and 4 were manufactured by being cured by irradiation with UV light.

[Evaluation of lighting equipment]
For each of the manufactured lighting devices, in the same manner as described in Example 1, evaluation of external extraction quantum efficiency, evaluation of half-life, evaluation of driving voltage (driving voltage rise resistance) and thermal stability were evaluated. The results obtained are shown in Tables 25-36. The evaluation of the external extraction quantum efficiency, the half-life, and the driving voltage was expressed as a relative value with the measured value of the organic EL element 3-1 being 100. Moreover, evaluation of thermal stability was displayed by the relative value which sets the measured value of the organic EL element produced for each 1st as 100.

  The evaluation of the thermal stability is based on the amount of the blue light emitting dopant compound necessary for forming the light emitting layer of the organic EL element 10 times on the resistance heating boat made of molybdenum in the formation of the light emitting layer of each organic EL element. 10 organic EL elements were continuously manufactured while heating the same heating boat (for example, for the organic EL element 3-1, organic EL elements 3-1-1, 3-1-2, 3-1-3, ..., 3-1-10 were produced.). In addition, about formation materials other than a blue luminescent dopant compound, it replaced | exchanged for a new material, whenever each organic EL element was produced.

  The organic EL element (for example, organic EL element 3-1-1) produced for the first time of each organic EL element, and the organic EL element (for example, organic EL element) produced using the dopant compound that has undergone the third deposition process. 3-1-3) About each of the organic EL elements (for example, organic EL element 3-1-10) produced using the dopant compound that has undergone the tenth vapor deposition treatment, the same manner as described in Example 1, Half-life was measured.

Evaluation of the thermal stability of each organic EL element is based on the half-life of the organic EL element produced for the first time of each organic EL element (for example, organic EL element 3-1-1, organic EL element 3-2-1, etc.). (Half-life: τ _1/2 ) is set to 100, and relative half lives of organic EL elements (for example, organic EL element 3-1-3, organic EL element 3-2-3, etc.) prepared for the third time, And the relative half life of the element (for example, organic EL element 3-1-10, organic EL element 3-2-10 etc.) produced for the 10th time was computed. The closer the value is to 100, the better the thermal stability of the dopant compound when the light emitting layer of the organic EL element is continuously formed.

  In addition, when it supplied with electricity to the produced said organic EL elements 3-1 to 3-563, it turned out that substantially white light emission is obtained and it can be used as an illuminating device.

  As is clear from the results shown in Tables 25 to 36, the organic EL device of the present invention that emits white light using the dopant compound of the present invention and the conventional dopant compound in combination has higher light emission than the comparative organic EL device. It can be seen that the efficiency and long life are exhibited, the voltage rise during driving is suppressed, and the thermal stability is also achieved.

Example 4
<< Production of organic EL element >>
[Production of Organic EL Element 4-1]
(Production of blue light emitting element)
The organic EL element 1-5 produced in Example 1 was used as a blue light emitting element.

(Production of green light emitting element)
In the production of the organic EL device 1-5 described in Example 1, a green light emitting device was produced in the same manner except that Exemplified Compound D-9 was changed to Exemplified Compound D-1 as a dopant compound. Used as an element.

(Production of red light emitting element)
In the production of the organic EL device 1-5 described in Example 1, a red light emitting device was produced in the same manner except that Exemplified Compound D-9 was changed to Exemplified Compound D-6 as a dopant compound. Used as a light emitting element.

  The red, green, and blue light-emitting organic EL elements produced above were juxtaposed on the same substrate to produce an active matrix type full-color display device having a configuration as shown in FIG. In FIG. 2, only the schematic diagram of the display part A of the produced display device is shown.

  That is, a plurality of pixels 3 (light emission color is a red region pixel, a green region pixel, a blue region pixel, etc.) juxtaposed with a wiring portion including a plurality of scanning lines 5 and data lines 6 on the same substrate. 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 (for details, see 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. The 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 red, green, and blue pixels.

  It has been found that when this full-color display device is driven, high brightness, high durability, and clear full-color moving image display can be obtained.

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line A Display part B Control part 101 Organic EL element 102 Glass cover 105 Cathode 106 Organic EL layer 107 Glass substrate with a transparent electrode 108 Nitrogen gas 109 Water trapping agent

Claims (16)

An organic electroluminescence device having an organic layer including at least one light emitting layer, wherein at least one of the organic layers contains a metal complex represented by the following general formula (1) Luminescence element.
General formula (1)
ML ¹ · L ² · (L ³ ) _n
[Wherein, ML ¹ represents a partial structure represented by the following general formula (2), and M represents a group 8-10 metal atom in the periodic table of elements. L ^{1 to} L ³ each represents a divalent ligand, and L ^{1 to} L ³ may be the same or different, and may be bonded to each other. n represents 1 or 0. ]

[Wherein, X represents a carbon atom or a nitrogen atom. A ¹ represents an atomic group necessary for forming a 5- or 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring together with X—C. A ² represents an atomic group necessary for forming a 5-membered aromatic heterocyclic ring together with N—C—N. A ³ represents an atomic group necessary for forming a 6-membered aromatic hydrocarbon ring or aromatic heterocyclic ring together with C—C—C. R ¹ , R ² and R ³ each represent a substituent capable of substituting for A ¹ , A ² and A ³ . n1 represents an integer of 0 to 4, n2 represents an integer of 0 to 2, and n3 represents an integer of 0 to 2. When there are a plurality of R ^{1 to} R ³ , the substituents may be the same as or different from each other. Ar represents a 5-membered or 6-membered aromatic hydrocarbon ring or heteroaromatic ring which may have a substituent. n4 represents an integer of 1 to 3. When Ar is more, Ar may be the same or different, Ar may form a fused ring with the ring formed by A ^3. R ⁴ and R ⁵ each represent a hydrogen atom or a substituent, and at least one of R ⁴ and R ⁵ represents an acyclic alkyl group having 5 to 20 carbon atoms that may have a substituent. ] The organic electroluminescent device according to claim 1, wherein the partial structure represented by the general formula (2) is a partial structure represented by the following general formula (3).

[Wherein, Ar represents a 5-membered or 6-membered aromatic hydrocarbon ring or heteroaromatic ring which may have a substituent. n4 represents an integer of 1 to 3. When there are a plurality of Ars, Ars may be the same or different, and may form a condensed ring together with the benzene ring substituted by Ar. R ⁴ and R ⁵ each represent a hydrogen atom or a substituent, and at least one of R ⁴ and R ⁵ represents an acyclic alkyl group having 5 to 20 carbon atoms. R ³ represents a substituent that can be substituted on the benzene ring. n3 represents an integer of 0 to 2. When there are a plurality of R ^{3 s} , R ³ may be the same or different from each other. R ^{11 to} R ¹⁶ each represent a hydrogen atom or a substituent. ] 2. The organic electroluminescence device according to claim 1, wherein at least one of R ⁴ and R ⁵ in the general formula (2) is an acyclic branched alkyl group having 5 to 15 carbon atoms. 3. The organic electroluminescent device according to claim 2, wherein at least one of R ⁴ and R ⁵ in the general formula (3) is an acyclic branched alkyl group having 5 to 15 carbon atoms.   The organic electroluminescence device according to claim 1 or 3, wherein Ar in the general formula (2) is a 5-membered or 6-membered aromatic hydrocarbon ring.   The organic electroluminescence device according to claim 2 or 4, wherein Ar in the general formula (3) is a 5-membered or 6-membered aromatic hydrocarbon ring.   The organic electroluminescent element according to claim 1 or 3, wherein Ar in the general formula (2) is a 5-membered or 6-membered aromatic heterocyclic ring.   The organic electroluminescence device according to claim 2 or 4, wherein Ar in the general formula (3) is a 5-membered or 6-membered aromatic heterocyclic ring. 9. The organic electroluminescence device according to claim 1, wherein all of L ^{1 to} L ³ in the general formula (1) have the same chemical structure. The organic electroluminescence device according to any one of claims 1 to 9, wherein L ¹ and L ² in the general formula (1) have different chemical structures. In addition to connecting at least one of L ^{1 to} L ³ in the general formula (1) via M, L ¹ and L ² , L ² and L ³ , or L ¹ and L ³ are The organic electroluminescence device according to claim 1, wherein the organic electroluminescence device is connected via a valent linking group.   The organic electroluminescence element according to any one of claims 1 to 11, wherein M in the general formula (1) is iridium.   The organic electroluminescent element according to any one of claims 1 to 12, wherein the organic layer containing the metal complex represented by the general formula (1) is a light emitting layer.   The organic electroluminescence element according to any one of claims 1 to 13, wherein the organic electroluminescence element emits white light.   A display device comprising the organic electroluminescence element according to claim 1.   An illuminating device comprising the organic electroluminescence element according to claim 1.

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