JP2012074444A - Material for organic electroluminescent element, organic electroluminescent element, display element, lighting system and metal complex compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a new metal complex compound; a material for an organic electroluminescent element containing the metal complex compound; an organic electroluminescent element which contains the material, is excellent in efficiency and stability, and generates only a small number of dark spots; and a display system and a lighting system including the element.SOLUTION: The material for an organic electroluminescent element is a metal complex represented by the following general formula (1).

Description

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

  Conventionally, there is an electroluminescence display (hereinafter referred to as ELD) as a light-emitting electronic display device. Examples of the 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 a high voltage is required to drive the light emitting elements.

  An organic electroluminescence device has a light-emitting layer containing a compound that emits light, and a structure in which a plurality of organic compound layers are sandwiched between a cathode and an anode as necessary. It is an element that emits light by utilizing the emission of light (fluorescence / phosphorescence) when excitons (excitons) are generated by bonding, and the excitons are deactivated. Since it is capable of emitting light by voltage, and is self-luminous, it has a wide viewing angle, high visibility, and since it is a thin-film complete element solid, it has been attracting attention from the viewpoint of space saving and portability.

  However, in the organic electroluminescence device for practical use in the future, development of an organic electroluminescence device that emits light with higher efficiency and longer life is desired.

  In addition, it has become clear that not only fluorescent materials but also phosphorescent materials can be used as light-emitting materials for organic electroluminescence elements, and research and development has been conducted earnestly. The generation ratio of singlet excitons and triplet excitons is 1: 3. In the case of fluorescent materials, only excited singlets can be used, whereas in the case of phosphorescent materials, excitation is performed in addition to excited singlets. Since triplet can also be used, the upper limit of internal quantum efficiency can be made 100%.

  For this reason, when a phosphorescent material is used compared to a fluorescent material, the luminous efficiency is four times in principle, and there is a possibility of obtaining almost the same performance as a cold cathode tube. ing.

  On the other hand, as a means of improving the lifetime of organic electroluminescence devices, research focused on the structure of the compound contained has resulted in the discovery of some materials that could withstand practical use. Yes.

  However, introduction of substituents and small changes in the structure such as the introduction position have a great influence on various characteristics such as lifetime and light emission characteristics, and are difficult to predict. (See Patent Documents 1 to 4).

  For example, in Patent Document 1, a stable organic compound having a long luminance half-life is obtained by using a metal coordination compound having a structure in which three returns of 6-5-6 are condensed as a substituent or a cyclic group bonded to a metal. Although it is described that an EL element can be provided, there is a demand for an organic EL element that is still insufficient in practical use and that exhibits sufficient practical characteristics (long half life).

Japanese Patent No. 4307000 JP 2008-147424 A Special table 2008-528646 gazette International Publication No. 2007-078184

  An object of the present invention is to provide a novel metal complex compound, a material for an organic electroluminescence device containing the metal complex compound, and the material, which is excellent in efficiency and stability, and produces less dark spots (DS). An organic electroluminescence element, a display device including the element, and a lighting device are provided.

  The above object of the present invention has been achieved by the following constitution.

  1. A material for an organic electroluminescence device, which is a metal complex represented by the following general formula (1).

[Wherein, A represents a 5- or 6-membered aromatic hydrocarbon ring group, a group represented by the following general formula (2), or a 5-membered or 6-membered aromatic heterocyclic group; Represents a 6-membered aromatic heterocyclic group or a group represented by the following general formula (2), A and B, and A and M are bonded by a covalent bond, and B and M are coordinate bonds Are bound by. M represents a transition metal element belonging to Groups 8 to 10 in the periodic table, and L represents an arbitrary ligand capable of coordinating with M. m represents an integer of 1 to 3, and n represents an integer of 0 to 2. However, one group always contains one group represented by the following general formula (2). ]

[Wherein, Q1, Q3 and Q5 each represent a 6-membered aromatic hydrocarbon ring or a 6-membered aromatic heterocycle, and Q2 and Q4 each represent a cyclopentadiene ring or a 5-membered aromatic heterocycle. ]
2. 2. The organic electroluminescent element material according to 1 above, which has at least one group represented by the general formula (2) as a substituent of A or B in the general formula (1).

  3. 3. The material for an organic electroluminescence device according to 1 or 2, wherein Q2 and Q4 in the general formula (2) are each a 5-membered aromatic heterocyclic ring containing a nitrogen atom or an oxygen atom.

  4). B of said General formula (1) is a 5-membered nitrogen-containing aromatic heterocyclic ring, The organic electroluminescent element material as described in any one of said 1-3 characterized by the above-mentioned.

  5. M of the said General formula (1) is platinum or iridium, The organic electroluminescent element material as described in any one of said 1-4 characterized by the above-mentioned.

  6). The organic electroluminescent element characterized by containing the organic electroluminescent element material of any one of said 1-5.

  7). 6. The organic electroluminescence device according to 6 above, wherein the layer containing the material for an organic electroluminescence device according to any one of 1 to 5 is formed by a wet process.

  8). A display element comprising the organic electroluminescence element as described in 6 or 7 above.

  9. 8. An illuminating device comprising the organic electroluminescence element as described in 6 or 7 above.

  10. The metal complex compound represented by General formula (1) of any one of said 1-5.

  According to the present invention, a novel metal complex compound, a material for an organic electroluminescence device containing the metal complex compound, an organic electroluminescence device containing the material, excellent in efficiency and stability, and generating less dark spots, A display device and a lighting device provided with the element could be provided.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. It is a schematic diagram of a display part. It is the schematic of an illuminating device. It is sectional drawing of an illuminating device.

  In the material for organic electroluminescent elements of the present invention, by having the structure according to any one of claims 1 to 5, an organic electroluminescent element material containing a novel metal complex compound is provided, It was possible to provide an organic electroluminescence element containing a material, excellent in efficiency and stability, and generating less dark spots, and a display device and a lighting device including the element.

  In addition, a novel metal complex compound could be provided.

  In order to solve the above-mentioned problems to be solved by the present invention, the present inventors have continued to study compounds having a conventionally known 6-5-6 fused ring structure. The performance prediction was very difficult.

  However, in view of the above-mentioned problems, the present inventors have continued investigations while paying attention to polycyclic compounds during further studies.

  As a result, instead of the 6-5-6 condensed ring structure, a novel metal complex compound using a ligand having a 6-5-6-5-6 condensed ring structure is applied to a material for an organic EL device. Thus, it was revealed that an organic EL element having excellent efficiency and stability (particularly capable of suppressing deterioration of initial luminance) can be provided.

  In addition, as an unexpected effect, it has also been clarified that an organic EL element that suppresses the formation of dark spots can be provided.

  Further, by using the metal complex (metal complex compound) represented by the general formula (1) according to the present invention as a luminescent dopant and using a compound having a specific structure as a luminescent host or an adjacent layer organic material, more luminous efficiency can be obtained. It has been clarified that an organic electroluminescence device that is high, has high stability (long half life), and produces less dark spots (DS) can be provided.

  By using the organic electroluminescence device material containing the metal complex represented by the general formula (1), the effect of the present invention can be obtained. Introducing the condensed ring structure into the luminescent dopant prevents the structural displacement between the ground and excited states, suppresses the aggregation of the luminescent dopant due to steric hindrance, and delocalizes the cation and anion radicals generated during charge transport. The radical conjugation stabilization effect obtained by maintaining the interaction with the host molecule moderately, the energy transfer efficiency between the host and the luminescent dopant is improved, the dispersibility improvement effect, the trace impurities in the organic layer derived from the improvement of the dispersibility It is estimated that various effects such as the effect of reducing the influence of dispersion were obtained.

  All of these effects are largely derived from the specific condensed ring structure contained in the compound according to the present invention, the stability of the compound itself according to the present invention is increased, and the interaction with other organic materials is moderate. It is thought that it was possible to adjust to.

  Hereinafter, the present invention will be described in detail.

《Materials for organic electroluminescence elements》
The organic electroluminescent element material of the present invention will be described.

The material for an organic electroluminescence element of the present invention is characterized in that it is a metal complex (metal complex compound) represented by the above general formula (1),
<< Metal Complex Represented by Formula (1) (Metal Complex Compound)
The metal complex represented by the general formula (1) according to the present invention (also referred to as a metal complex compound) will be described.

  In the general formula (1), examples of the 5- or 6-membered aromatic hydrocarbon ring group represented by A include a phenyl group, a p-chlorophenyl group, a mesityl group, a tolyl group, a xylyl group, a naphthyl group, and an anthryl group. Group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group and the like.

  Of these, a phenyl group is preferred.

  These groups may further have a substituent described later.

  In the general formula (1), the 5- or 6-membered aromatic heterocyclic group represented by A is represented by, for example, a pyridyl group, a quinolyl group, a pyrimidyl group, a furyl group, a pyrrolyl group, an imidazolyl group, or a benzoimidazolyl group. , Pyrazolyl group, pyrazinyl group, triazolyl group and the like.

  Of these, a pyridyl group, a quinolyl group, a pyrazolyl group, an imidazolyl group, a benzoimidazolyl group, and a triazolyl group are preferable.

  These groups may further have a substituent described later.

  In the general formula (1), the 5-membered or 6-membered aromatic heterocyclic group represented by B has the same meaning as the 5-membered or 6-membered aromatic heterocyclic group represented by A in the general formula (1). It is.

<< Substituent >>
In the general formula (1), each group represented by A and B may further have a substituent, such as an alkyl group, a cycloalkyl group, an alkynyl group, an aromatic hydrocarbon. Ring group (also called aromatic carbocyclic group, aryl group, etc., for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl Group, indenyl group, pyrenyl group, biphenylyl group, etc.), aromatic heterocyclic group (for example, pyridyl group, pyrimidyl 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.)), oxy Zolyl 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 A diazacarbolyl group (wherein one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), a quinoxalinyl group, a triazinyl group, a quinazolinyl group, a phthalazinyl group, etc.), a heterocyclic group (for example, a pyrrolidyl group, an imidazolidyl group) Group, morpholinyl group, oxazolidyl group, etc.), alkoxy group, cycloalkoxy group, aryloxy group, alkylthio group, cycloalkylthio group, arylthio group, carbonyl group, alkoxycarbonyl group, aryloxy Rubonyl group, sulfamoyl group, acyl group, acyloxy group, amide group, carbamoyl group, ureido group, sulfinyl group, alkylsulfonyl group, arylsulfonyl group, heteroarylsulfonyl group, amino group, halogen atom, fluorinated hydrocarbon group, cyano Group, nitro group, hydroxy group, thiol group, silyl group, phosphono group and the like.

  These groups may further have the above substituent.

  A and B and A and M are bonded by a covalent bond, B and M are bonded by a coordinate bond, and even if the coordination atom of B is a heteroatom such as nitrogen or oxygen, Any carbon atom may be used depending on the structure, preferably a nitrogen atom or a carbon atom.

  In the general formula (1), M represents a group 8-10 group transition metal element (also simply referred to as a transition metal) in the periodic table, and among these, iridium and platinum are preferable, and iridium is more preferable.

  In the general formula (1), L represents an arbitrary ligand capable of coordinating with M, and L is a ligand well known to those skilled in the art. There are various known ligands used in conventionally known metal complexes. For example, “Photochemistry and Photophysics of Coordination Compounds” Springer-Verlag H. Published by Yersin in 1987, “Organometallic Chemistry-Fundamentals and Applications-” Liu Huabo Company, Akio Yamamoto, published in 1982, etc. (for example, halogen ligands (preferably chlorine ligands), Nitrogen heterocyclic ligands (for example, bipyridyl, phenanthroline, etc.) and diketone ligands).

  Furthermore, substituted or unsubstituted phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabol, picolinic acid, carbene and the like can be used in combination as a preferred ligand.

  In the formula, m represents an integer of 1 to 3, n represents an integer of 0 to 2, and these can take values according to the valence of the transition metal represented by M, but preferably m + n = In this case, m is preferably 2 or 3, and m is most preferably 3.

  Among the metal complexes (metal complex compounds) represented by the general formula (1) according to the present invention, metal complexes (metal complex compounds) represented by the following general formula (3) or (4) are preferable.

  << Metal Complex Represented by General Formula (3) or (4) >>

In General formula (3), T represents -N ( _R300 )-, an oxygen atom, or a sulfur atom. Here, R ₃₀₀ represents a substituent, and the substituent is synonymous with the substituent that the groups represented by A and B in the general formula (1) may further have.

  Among these, an alkyl group, a cycloalkyl group, an aromatic hydrocarbon ring group, and an aromatic heterocyclic group are preferable, and a branched alkyl group and an aromatic hydrocarbon ring group having a substituent are more preferable.

In General Formula (3), R ₃₀₁ and R ₃₀₂ each represent a hydrogen atom or a substituent, and the substituent is further included in the groups represented by A and B in General Formula (1), respectively. It is synonymous with the substituent which may be present.

  In the general formula (3), M, L, m, and n have the same meanings as M, L, m, and n in the general formula (1), respectively.

In General Formula (4), U ₁ and U ₂ each represent a carbon atom or a nitrogen atom, R _{401 to} R ₄₀₃ each represent a hydrogen atom or a substituent, and the substituent in General Formula (1) , A and B have the same meanings as the substituents that may be further present.

Among these, R ₄₀₃ particularly preferably represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group, and more preferably an aromatic hydrocarbon ring group.

  In the general formula (4), o and p are integers of 0 or 1, and when U1 is a nitrogen atom, o is 0. Similarly, when U2 is a nitrogen atom, p is 0.

  In General formula (4), M, L, m, and n are synonymous with M, L, m, and n of the said General formula (1).

  The metal complex (metal complex compound) represented by the general formula (1) according to the present invention has at least one group represented by the above general formula (2) as a substituent of A or B or A and B. It is a feature of the present invention that it exists.

Moreover, the metal complex (metal complex compound) represented by the general formula (3) or the general formula (4), which is a preferred embodiment of the metal complex (metal complex compound) represented by the general formula (1) according to the present invention. in as a, or, as a substituent of _a, having a group represented as the substituent represented by R 300 _{to R 302} and _R 401 _{to R 403} in the general formula (2).

<< Group Represented by General Formula (2) >>
The group represented by the general formula (2) according to the present invention will be described.

  In the general formula (2), a benzene ring is used as the 6-membered aromatic hydrocarbon ring represented by Q1, Q3 and Q5.

  In the general formula (2), the 6-membered aromatic heterocyclic ring represented by Q1, Q3 and Q5 has the same meaning as the 6-membered aromatic heterocyclic group represented by A in the general formula (1). Among them, a pyridine ring is preferable.

  In general formula (2), each of the cyclopentadiene rings represented by Q2 and Q4 may be unsubstituted or may have a substituent. Among them, as a substituent, a carbonyl group as a substituent. It is preferable to form a cyclopentadienone ring.

  In the general formula (2), the 5-membered aromatic heterocyclic ring represented by Q2 and Q4 respectively has the same meaning as the 5-membered aromatic heterocyclic group represented by A in the general formula (1). , Furan ring and pyrrole ring are preferred.

  In the compound represented by the general formula (1) as described above, the group represented by the general formula (2) according to the present invention is present as a substituent of A or B or at least one of A and B. More preferably, it is present as a substituent or A for A or B, more preferably it is present as a substituent for A or A, and most preferably it is present as a substituent for B. That is.

  Preferable embodiments of the group (also referred to as partial structure) represented by the general formula (2) according to the present invention include groups represented by the following general formulas (Q-1) to (Q-5).

  << Groups Represented by General Formulas (Q-1) to (Q-5) >>

In the general formulas (Q-1) to (Q-5), X ₁ and X ₂ each independently represent N (R ₁ ), C (R ₂ ) (R ₃ ), O or S.

Here, R _{1 to} R ₃ each represent a hydrogen atom or a substituent, and the substituent is a substituent that each group represented by A and B in the general formula (1) may further have. Synonymous with group.

R ₁ is preferably an alkyl group, an aromatic hydrocarbon ring group, or an aromatic heterocyclic group, and more preferably an aromatic hydrocarbon ring group or an aromatic heterocyclic group.

R ₂ and R ₃ are preferably an alkyl group, an aromatic hydrocarbon ring group or an aromatic heterocyclic group, more preferably an alkyl group or an aromatic heterocyclic group.

In the general formulas (Q-1) to (Q-5), Y _{11 to} Y ₆₀ each independently represent —C (Ryy) =, —N =, and yy of Ryy represents the corresponding Y ₁₁ to Y ₆₀ . Y represents a two-digit number less than Y, each independently represents a hydrogen atom or a substituent, and the substituent may be further represented by the groups represented by A and B in the general formula (1). Synonymous with good substituents.

  Among these, an alkyl group, an aromatic hydrocarbon ring group, an aromatic heterocyclic group, an amino group, or a phosphono group is preferable.

However, the general formula (Q-1) ~ (Q -5) is, in the case of A or B is _{R 11 ~R 20, R 21 ~R} 30, R 31 ~R 40, R 41 ~R 50, R Of the groups represented by _{51 to} R ₆₀ , two represent a single bond between A and B and a bond of M, and the above general formulas (Q-1) to (Q-5) are represented by A or B Is one of the groups represented by R _{11 to} R ₂₀ , R _{21 to} R ₃₀ , R _{31 to} R ₄₀ , R _{41 to} R ₅₀ , and R _{51 to} R _60. Is a single bond that bonds A or B to the general formulas (Q-1) to (Q-5).

  Among the groups represented by the general formulas (Q-1) to (Q-5), any one of the general formula (Q-1), the general formula (Q-4), and the general formula (Q-5) is preferable. More preferably, it is (Q-4) or (Q-5).

  Hereinafter, although the specific example of a compound represented by General formula (1) of this invention is given, this invention is not limited to these.

  In addition, the compound represented by General formula (1) of this invention is The Journal of Organic Chemistry. 72, 5119-5128 (2007), Japanese translations of PCT publication No. 2008-545630, International Publication No. 2009/148016, International Publication No. 2009/148062, Inorg. Chem. 40, pages 1704 to 1711 and the above-mentioned prior art can be used as a reference for synthesis.

  The compound according to the present invention may be contained in any organic layer in the organic electroluminescence device, and each organic layer may be composed of the compound according to the present invention alone or mixed with other materials. May be used. The use of the compound according to the present invention is preferably used as a light emitting material, a hole transport material, and an electron transport material, more preferably used as a light emitting material and a hole transport material, and more preferably light emission. It is used as a material, and is most preferably used as a light emitting dopant (phosphorescent dopant), particularly in a light emitting layer.

  Moreover, in the organic electroluminescent element containing the compound according to the present invention, it is preferable that any one of the organic layers contains a compound having a structure represented by any one of the following general formulas (5) to (7).

  In the structure represented by any one of the general formulas (5) to (7), the ring B represents the structure represented by the general formula (6) bonded to two adjacent rings at an arbitrary position. The structure B is condensed to connect the ring A and the ring C, and the ring C represents the structure represented by the general formula (7).

X ₁ and X ₂ each independently represents an oxygen atom, a sulfur atom, N (R 5), C (R 6) (R 7) or C═O, preferably an oxygen atom or N (R 5).

Moreover, it is more preferable that either X ₁ or X ₂ is an oxygen atom, and it is further preferable that X ₁ and X ₂ are a combination of oxygen and N (R 5).

  R5 to R7 each represent a hydrogen atom or a substituent, and the substituent is synonymous with a substituent that the groups represented by A and B in the general formula (1) may further have. .

  Among these, an alkyl group, an aromatic hydrocarbon ring group, or an aromatic heterocyclic group is preferable. Further, the group may further have a substituent, and may further be bonded to each other to form a ring.

  Ra, Rb, and Rc each represent a hydrogen atom or a substituent, and the substituent is synonymous with the substituent that each of the groups represented by A and B in the general formula (1) may further have. It is.

  Among them, an aromatic hydrocarbon ring group, an aromatic heterocyclic group or an amino group is preferable, and a dibenzofuryl group, a carbazolyl group, a carbolinyl group, a diazacarbazolyl group or a diarylamino group is more preferable. Particularly preferred is a carbazolyl group, carbolinyl group or diarylamino group.

  These groups may be bonded by a carbon-carbon bond, may be bonded by a carbon-nitrogen bond, and may further have a substituent.

  o represents an integer of 0 to 4, p represents an integer of 0 to 2, q represents an integer of 0 to 4, and more preferably o + q ≧ 1.

Y and Z _{1 to} Z ₄ represent a carbon atom or a nitrogen atom, and together with other constituent atoms of the ring form a 6-membered aromatic ring. When any of Z ₁ , Z ₂ , Z ₃ and Z ₄ represents a nitrogen atom, it is more preferable that either Z ₁ or Z ₃ is a nitrogen atom.

  The compound represented by any one of the general formulas (5) to (7) may be contained in the same layer as the compound represented by the general formula (1) according to the present invention, or other layers. It is preferably contained in the same layer as the compound represented by the general formula (1) of the present invention and in an adjacent layer of the layer, and most preferably contained in the same layer. Is Rukoto.

<< Constituent layers of organic EL elements >>
The constituent layers of the organic EL element of the present invention will be described. In the present invention, preferred specific examples of the layer structure of the organic EL element are shown below, but the present invention is not limited thereto.

(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 In the organic EL device of the present invention, the blue light emitting layer preferably has a light emission maximum wavelength of 430 nm to 480 nm, and the green light emitting layer has a light emission maximum wavelength of 510 nm to 550 nm, The red light emitting layer is preferably a monochromatic light emitting layer having a light emission maximum wavelength in the range of 600 nm to 640 nm, and is preferably a display element using these.

  Alternatively, a white light emitting layer may be formed by laminating at least three light emitting layers. Further, a non-light emitting intermediate layer may be provided between the light emitting layers.

  The organic EL element of the present invention is preferably a white light emitting layer, and is preferably a lighting device using these.

  Each layer which comprises the organic EL element of this invention is demonstrated.

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

  There is no particular limitation on the total thickness of the light emitting layer, but from the viewpoint of preventing the application of unnecessary high voltage during film homogeneity and light emission, and improving the stability of the light emission color with respect to the drive current It is preferable to adjust to the range of 5 micrometers, More preferably, it adjusts to the range of 2 nm-200 nm, Most preferably, it is the range of 10 nm-40 nm.

  The light emitting layer of the organic EL device of the present invention contains a light emitting dopant (phosphorescent dopant (also referred to as phosphorescent dopant group) or fluorescent dopant) compound and a host compound.

(Luminescent dopant compound)
The luminescent dopant compound will be described.

  As the luminescent dopant compound, a fluorescent dopant compound or a phosphorescent dopant compound can be used.

(Phosphorescent dopant compound)
The phosphorescent dopant compound according to the present invention will be described.

  The phosphorescent dopant compound according to 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 a phosphorescence quantum yield of 25 ° C. The phosphorescence quantum yield is preferably 0.1 or more.

  The above 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 compound according to the present invention can achieve the phosphorescence yield of 0.01 or more in any solvent. It ’s fine.

  There are two types of emission principles of the phosphorescent dopant compound. One is the recombination of carriers on the host compound to which carriers are transported, and the excited state of the luminescent host compound is generated. Energy transfer type that obtains light emission from phosphorescent dopant by moving to optical dopant.

  The other is a carrier trap type in which the phosphorescent dopant compound itself becomes a carrier trap, carrier recombination occurs on the phosphorescent dopant, and light emission from the phosphorescent dopant compound is obtained. It is a condition for obtaining good light emission that the excited state energy of the phosphorescent dopant compound is lower than the excited state energy of the host compound.

  Although the specific example of the well-known compound used as a phosphorescence dopant below is shown, this invention is not limited to these. These compounds are described in, for example, Inorg. Chem. 40, pages 1704 to 1711, and the like.

  Although the example of a light emission dopant is given to the following, it is not limited to these.

(Fluorescent dopant compound)
As fluorescent dopant compounds, coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squarylium dyes, oxobenzoanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes, Examples include stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

(Luminescent host compound (also referred to as luminescent host))
As the light-emitting host compound used in the light-emitting layer and the light-emitting unit of the organic EL device of the present invention, among the compounds contained in the light-emitting layer, the mass ratio in the layer is 20% or more and room temperature (25 ° C) is defined as a compound having a phosphorescence quantum yield of less than 0.1, preferably a phosphorescence quantum yield of less than 0.01. Moreover, it is preferable that the mass ratio in a layer is 20% or more among the compounds contained in a light emitting layer.

  As the host compound, known host compounds may be used alone or in combination of two or more. By using a plurality of types of host compounds, it is possible to adjust the movement of carriers, and the performance of the organic EL element can be further increased.

  Moreover, it becomes possible to mix different light emission by using multiple types of well-known compounds used as the said phosphorescence dopant, and, thereby, arbitrary luminescent colors can be obtained.

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

  Known light-emitting host compounds typically 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.

  A known host compound that may be used in combination is preferably a compound that has a hole transporting ability and an electron transporting ability, prevents a long wavelength of light emission, and has a high Tg (glass transition temperature).

  Specific examples of known host compounds include, but are not limited to, compounds described in the following 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.

  In particular, in combination with the compound of the present invention, Japanese translations of PCT publication No. 2008-545630, WO2007 / 063754, International Publication No. 2007/063796, International Publication No. 2008/056746, International Publication No. 2009/136586, International Publication No. Publications such as Publication No. 2009/136595, International Publication No. 2009/136596, International Publication No. 2009/148015, International Publication No. 2009/148016, International Publication No. 2009/148062, and Japanese Unexamined Patent Application Publication No. 2010-45281 It is more preferable to use a host compound having a 65656 condensed ring structure as described.

  Next, an injection layer, a blocking layer, a transport layer and the like used as the constituent layers of the organic EL element of the present invention will be described.

<Injection layer: electron injection layer, hole transport 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 is present between the anode and the light emitting layer, or the hole transport layer, the cathode and the light emitting layer, or the electron transport layer. Also good.

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

  The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45579, JP-A-9-260062, JP-A-8-288069, and the like, and representative examples thereof include copper phthalocyanine. Phthalocyanine buffer layers, oxide buffer layers typified by vanadium oxide, amorphous carbon buffer layers, polymer buffer layers using conductive polymers such as polyaniline (emeraldine) and polythiophene, and the like.

  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 or aluminum Metal buffer layer represented by lithium fluoride, alkali metal compound buffer layer represented by lithium fluoride, alkaline earth metal compound buffer layer represented by magnesium fluoride, oxide buffer layer represented by aluminum oxide, etc. It is done.

  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.

<Blocking layer: hole blocking layer, electron blocking layer>
As described above, the blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film. For example, described in JP-A Nos. 11-204158 and 11-204359, and “Organic EL devices and the forefront of industrialization (November 30, 1998, issued by NTS Corporation)” on page 237, etc. There is a hole blocking layer (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 having a function of transporting electrons and having a remarkably small ability to transport holes. By blocking hole transport, the recombination probability of electrons and holes can be improved.

  Moreover, the structure of the electron carrying layer mentioned later can be used as a hole-blocking layer concerning this invention as needed.

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

  The hole blocking layer preferably contains the carbazole derivative, carboline derivative, diazacarbazole derivative, or the like mentioned as the host compound.

  Moreover, when it has several light emitting layers from which luminescent color differs, it is preferable that the light emitting layer with the shortest light emission maximum wavelength is the closest to an anode among all the light emitting layers.

  In such a case, it is preferable to additionally provide a hole blocking layer between the shortest wave light emitting layer and the light emitting layer next to the anode next to the light emitting layer.

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

  The ionization potential is defined as the energy required to emit electrons at the HOMO (highest occupied molecular orbital) level of the compound to the vacuum level, and can be obtained 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. The ionization potential can be obtained as a value obtained by rounding off the second decimal place of the value (eV unit converted value) calculated by performing structural 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) It can also be determined by a method of direct measurement by photoelectron spectroscopy. wear. For example, a method known as ultraviolet photoelectron spectroscopy can be suitably used using a low energy electron spectrometer “Model AC-1” manufactured by Riken Keiki.

  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 having a function of transporting holes and a very small ability to transport electrons, and transporting electrons while transporting holes. The probability of recombination of electrons and holes can be improved by blocking. Moreover, the structure of the positive hole transport layer mentioned later 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 nm to 100 nm, and more preferably 5 nm to 30 nm.

《Hole transport layer》
The hole transport layer is made of a hole transport material having a function of transporting holes. In a broad sense, the hole transport layer and the electron blocking layer can be regarded as being 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 polymers (polymers and 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. In addition, the organic EL device material of the present invention can be preferably used in the same manner.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N'-diphenyl-N, N'-bis (3-methylphenyl)-[1,1'-biphenyl] -4,4 '. -Diamine (TPD), 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD), 4,4 ', 4 "-tris [N- (3-methylphenyl) ) -N-phenylamino] triphenylamine (MTDATA).

  Furthermore, a polymer material in which these materials are introduced into a polymer chain or a polymer main chain can also be used. Inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole transport material. JP-A-11-251067, J. Org. Huang et al. A p-type hole transport material as described in a book (Applied Physics Letters 80 (2002), p. 139) can also be used.

  The hole transport layer is formed by thinning the hole transport material as described above by, for example, 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. be able to. Although there is no restriction | limiting in particular about the film thickness of a positive hole transport layer, Usually, 5 nm-5 micrometers, Preferably it is 5 nm-200 nm. Further, the hole transport material may have a single layer structure composed of a plurality of types of materials.

  Alternatively, a hole transport layer having a high p property doped with impurities can be used.

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

  An electron transport material (also serving as a hole blocking material) used for the electron transport layer adjacent to the cathode side with respect to the light emitting layer may have a function of transmitting electrons injected from the cathode to the light emitting layer. As the material, any one of conventionally known compounds can be selected and used. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthra Examples include quinodimethane and anthrone derivatives, oxadiazole derivatives, and the like.

  Furthermore, in the above oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron withdrawing group can also be used as an electron transport material. Furthermore, a polymer material in which these materials are introduced into a polymer chain or these materials are used as a polymer main chain can also be used.

  In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), 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, phthalocyanine materials and derivatives thereof can also be preferably used as the electron transport material. In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and the hole transport layer. Can also be used as an electron transporting material.

  The electron transport layer can be formed by thinning the electron 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. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, 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.

"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 electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO. Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used.

  For the anode, a thin film may be formed by vapor deposition or sputtering of these electrode materials, and a pattern may be formed through a photolithography method or a mask. 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 in the range of 10 to 1000 nm, preferably in the range of 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 a 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 nm to 200 nm. In order to transmit the emitted light, if either one of 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 said metal by the film thickness of 1 nm-20 nm to a cathode, the transparent or semi-transparent cathode can be produced by producing the electroconductive transparent material quoted by description of the anode on it, 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, cellulose esters (cellulose acetate propionate (CAP), cellulose acetate phthalate (TAC), and cellulose nitrate. Etc.) or derivatives thereof, polyvinylidene chloride, polyethylene vinyl alcohol, syndiotactic polystyrene, polycarbonate, norbornene resin, polymethylpentene, polyether ketone, polyimide, polyethersulfone (PES), polyphenylene sulfide, polysulfones, polyether Imide, polyether ketone imide, polyamide, fluororesin, nylon, polymethyl methacrylate, acrylic Alternatively polyarylates, and cycloolefin resins such as ARTON (manufactured by JSR) or APEL (manufactured by Mitsui Chemicals).

On the surface of the resin film, an inorganic film, an organic film, or a hybrid film of both may be formed. 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 · 24 h) or less, and further, oxygen measured by a method according to JIS K 7126-1987. Preferably, the film is a high barrier film having a permeability of 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less and a water vapor permeability of 10 ⁻³ g / (m ² · 24 h) or less, and moreover, a water vapor transmission rate. The degree is more preferably 10 ⁻⁵ g / (m ² · 24 h) or less.

  As a material for forming the barrier film, any material may be used as long as it has a function of suppressing intrusion of moisture or oxygen that causes deterioration of the element. For example, silicon oxide, silicon dioxide, silicon nitride, or the like is preferably used. it can. 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, or the like can be used, and an atmospheric pressure plasma polymerization method 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 quantum 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 with 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.

<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 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. Further, the polymer film has an oxygen permeability measured by a method according to JIS K 7126-1987 of 1 × 10 ⁻³ cm ³ / (m ² · 24 h · atm) or less, and conforms to JIS K 7129-1992. The water permeability (25 ± 0.5 ° C., relative humidity (90 ± 2)% RH) measured by the method is preferably 1 × 10 ⁻³ g / (m ² · 24 h) or less.

  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, when using a thermosetting adhesive, since an organic EL element may deteriorate with heat processing, what can be adhesively cured 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, barium oxide, magnesium oxide, aluminum oxide, etc.), sulfates (for example, sodium sulfate, calcium sulfate, magnesium sulfate, etc.), metal halides. Perchloric acids and the like, and anhydrous salts are preferably used.

《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 sealing is performed by the sealing film, it is preferable to provide 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, etc. used for the sealing can be used. It is preferable to use a film.

《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 extracted outside the device, 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 having 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, 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 or second-order diffraction, and light generated from the light-emitting layer. The light that cannot go out due to total reflection between layers, etc. is diffracted by introducing a diffraction grating in any layer or medium (in the transparent substrate or transparent electrode). It is intended to be taken 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 in 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 device of the present invention can be processed to provide, for example, a microlens array-like structure on the light extraction side of the substrate, or combined with a so-called condensing sheet, for example, in a specific direction, for example, the device light emitting surface. On the other hand, the brightness | luminance in a specific direction can be raised by condensing in a front direction.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are two-dimensionally arranged on the light extraction side of the substrate. One side is preferably 10 μm 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.

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

  First, a desired electrode material, for example, a thin film made of an anode material is formed on a suitable substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm, thereby producing an anode.

  Next, an organic compound thin film of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and a hole blocking layer, which are organic EL element materials, is formed thereon.

  As a method for forming each of these layers, there are a vapor deposition method, a wet process (spin coating method, casting method, ink jet method, printing method) and the like as described above, but it is easy to obtain a homogeneous film and it is difficult to generate pinholes. In view of the above, in the present invention, a wet process is preferable, and film formation by a coating method such as a spin coating method, an ink jet method, or a printing method is particularly preferable.

  Examples of the liquid medium for dissolving or dispersing the organic EL device material of 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 DMF and DMSO can be used. Moreover, as a dispersion method, it can disperse | distribute by dispersion methods, such as an ultrasonic wave, high shear force dispersion | distribution, and media dispersion | distribution.

  After these layers are formed, a thin film made of a cathode material is formed thereon by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 50 to 200 nm, and a cathode is provided. Thus, a desired organic EL element can be obtained.

  In addition, it is also possible to reverse the production order and produce the cathode, the electron injection layer, the electron transport layer, the light emitting layer, the hole transport layer, the hole injection layer, and the anode in this order. When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 V to 40 V with the anode as + and the cathode as-. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

<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 the total CS-1000 (manufactured by Konica Minolta Sensing) 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, slit coating, die coating, casting, spin coating, printing, or the like.

  In the case of patterning only the light emitting layer, the method is not limited, but preferably a vapor deposition method, a slit coating method, a die coating method, a spin coating method, or a printing method.

  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.

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

  The multicolor display device 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 to scan the image and display the 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 figure, the light 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.

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

  FIG. 3 is a schematic diagram of a pixel.

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

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

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

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

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

  Here, the light emission of the organic EL element 10 may be light emission of a plurality of gradations by a multi-value image data signal having a plurality of gradation potentials, or by turning on / off a predetermined light emission amount by a binary image data signal. Good. The potential of the capacitor 13 may be held continuously until the next scanning signal is applied, or may be discharged immediately before the next scanning signal is applied.

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

  FIG. 4 is a schematic diagram of a passive matrix display device. In FIG. 4, a plurality of scanning lines 5 and a plurality of image data lines 6 are provided in a lattice shape so as to face each other with the pixel 3 interposed therebetween.

  When the scanning signal of the scanning line 5 is applied by sequential scanning, the pixels 3 connected to the applied scanning line 5 emit light according to the image data signal.

  In the passive matrix system, the pixel 3 has no active element, and the manufacturing cost can be reduced.

《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, a full-color display device can be manufactured 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 as an illumination device to an organic EL element that emits substantially white light. 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. Further, for example, an electrode film can be formed by vapor deposition, slit coating, die coating, casting, spin coating, printing, etc., and productivity is 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 shows a schematic diagram of a lighting device, and the organic EL element 201 of the present invention is covered with a glass cover 202 (in the sealing operation with the glass cover, the organic EL element 201 is brought into contact with the atmosphere. And a glove box under a nitrogen atmosphere (in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more).

  4 shows a cross-sectional view of the lighting device. In FIG. 6, reference numeral 205 denotes a cathode, 206 denotes an organic EL layer, and 207 denotes a glass substrate with a transparent electrode. The glass cover 202 is filled with nitrogen gas 208 and a water catching agent 209 is provided.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to these. In addition, although the display of "%" is used in an Example, unless otherwise indicated, "mass%" is represented. The comparative compounds used in the examples are shown below.

Example 1
<< Synthesis Example: Synthesis of Exemplary Compound (2) >>

Step 1: Synthesis of Intermediate (B) Intermediate (A) synthesized with reference to WO2009 / 148016, 5.0 g (12 mmol) and 200 ml of dehydrated THF were added to a three-necked flask under a nitrogen stream, After (A) was dissolved, it was cooled using a dry ice / acetone bath.

Here, 15 ml of n-butyllithium (n-BuLi, 1.6 mol hexane solution) was added dropwise at -60 ° C or lower. After stirring for 1 hour, 1.6 g (15.4 mmol) of trimethoxyborane (B (OMe) ₃ ) was further added, and the temperature was gradually returned to room temperature over 1 hour. After adding 100 ml of 1N hydrochloric acid solution to this solution and stirring at room temperature for 1 hour, 100 ml of ethyl acetate was added, followed by liquid separation, washing with water, dehydration and concentration with magnesium sulfate, and column chromatography with ethyl acetate / heptane. Intermediate (B) was obtained in 2.4 g (55% yield).

Step 2: Synthesis of Ligand (D) 2.4 g (7.9 mmol) of Intermediate (B) synthesized above in a three-necked flask and 2.5 g (9.5 mmol) of Intermediate (C) synthesized separately, phosphorus Potassium acid (K ₃ PO ₄ ) (3.4 g, 15.9 mmol) and toluene (50 ml) were added, and deaerated by bubbling with nitrogen for 15 minutes while stirring. To this solution was added 0.09 g (0.4 mmol) of palladium acetate (Pd (OAc) ₂ ) and dicyclohexyl (2 ′, 6′-dimethoxy- [1,1′-biphenyl] -2-yl]) phosphine (S-Phos). ) After adding 0.3 g (0.8 mmol), the mixture was heated and stirred for 48 hours under a nitrogen stream. After cooling at room temperature, toluene was added, extracted, washed with water, dehydrated with magnesium sulfate, concentrated and subjected to column chromatography with ethyl acetate / heptane to obtain 1.8 g of ligand (D) (yield 51%). Obtained.

Step 3: Synthesis of Exemplary Compound (2) Into a three-necked flask, 1.8 g of the ligand (D) obtained above, trisacetylacetone iridium (Ir (acac) ₃ ), and 20 ml of glycerin were placed, and the mixture was heated at 175 ° C. under an argon stream. Reacted for hours.

  After completion of the reaction, the reaction solution is cooled, extracted with 50 ml of water and 100 ml of THF, extracted, washed with water, dried over sodium sulfate, and purified by preparative GPC and column chromatography to give 0.4 g of Exemplified Compound (2) ( (Yield 19%).

  In the preparation of the organic EL device of the present invention, which will be described later, a sample that was further subjected to sublimation purification twice was used.

Example 2
<< Production of Organic EL Element 1-1 >>
Each organic layer was laminated | stacked on the glass substrate with ITO patterned as an anode using the commercially available vacuum evaporation apparatus with the vacuum degree of 4.0 * 10 <^-4> Pa. First, the compound (F-2) is formed to a thickness of 20 nm as the hole transport / injection layer, and the concentration of the compound (F-1) as the host compound and the exemplified compound (2) as the light emitting dopant as the light emitting layer. The film was formed to a thickness of 40 nm so as to be 6% by mass.

Further, Alq ₃ was formed to a thickness of 40 nm as an electron transport layer. Subsequently, lithium fluoride was formed to a thickness of 0.5 nm as an electron injection layer, and then 150 nm of aluminum was formed as a cathode to produce an organic EL element 1-1 having a light emitting region of 2 mm × 2 mm square.

<< Production of Organic EL Elements 1-2 to 1-10 >>
In the production of the organic EL element 1-1, organic EL elements 1-2 to 1-10 were produced in the same manner except that the host compound and the luminescent dopant were changed as shown in Table 1.

<< Evaluation of Organic EL Elements 1-1 to 1-10 >>
As shown in FIGS. 3 and 4, the produced organic EL elements 1-1 to 1-10 covered the non-light emitting surface with a glass case and sealed with an epoxy adhesive, as described below. The efficiency, initial deterioration, half-life, and DS (dark spot) of each element were evaluated.

(efficiency)
For each device, the external extraction quantum efficiency when a constant current of ^2.5 mA / cm ² was applied was measured. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing Co., Ltd.) was used, the driving time was 10 minutes, and the measurement was completed at an arbitrary time.

  In addition, the value of the efficiency described in Table 1 is expressed as a relative value when the measured value of the organic EL element 1-1 is 100.

(Stability (initial deterioration, half life))
According to the following measurement method, stability was evaluated from the viewpoint of initial deterioration and half-life.

For each element, after performing the measurement of the efficiency, the initial luminance 5000 cd / ^{m 2} and a constant current drive with a current giving, to measure the time at which 90% of the initial luminance (4500cd / ^{m 2),} evaluating the initial deterioration did.

Subsequently, low current driving was performed, and driving was further performed to ½ of the initial luminance (2500 cd / m ² ), time was measured, and half life was evaluated.

  As in the evaluation of efficiency, the stability value is shown in Table 1 as a relative value when the measured value of the organic EL element 1-1 is 100.

(Dark spot (DS))
By using 10 samples of the organic EL elements 1-1 to 1-10 driven to half the initial luminance by the stability evaluation, each of the elements driven at a constant current was randomly extracted. Dark spots were observed by visual evaluation, and the following rank evaluation was performed.

×: When the number of confirmed dark spots is 8 or more △: When the number of confirmed dark spots is 5-7 persons ○: When the number of confirmed dark spots is 3-5 persons ◎: Confirmed dark spots When the number of people who have done is less than three, the practical ranks are ○ and ◎.

  The obtained results are shown in Table 1.

  From Table 1, compared with the comparative element, the organic EL element of the present invention produced using the organic EL element material of the present invention has excellent efficiency and good stability (especially, initial deterioration is suppressed, half-life is reduced). It is clear that the lifespan is long) and the DS (dark spot) is small.

Example 3
<< Preparation of Organic EL Element 2-1 >>
In the same manner as in the production of the organic EL device 1-1 of Example 1, after forming α-NPD to a thickness of 10 nm as a hole transport / injection layer, the substrate with a hole transport layer was moved to a nitrogen atmosphere. A solution prepared by dissolving compound (F-1) (80 mg) and exemplary compound (1) (3.5 mg) in 8 ml of toluene was spin-coated at 1000 rpm for 30 seconds, and then dried in vacuum at 80 ° C. for 1 hour to obtain a light emitting layer It was.

Furthermore, using a solution in which compound (F-4) (20 mg) was dissolved in 6 ml of toluene, a film was formed by spin coating under conditions of 1000 rpm and 30 seconds, and dried in vacuum at 120 ° C. for 1 hour. Subsequently, this substrate was transferred to a vacuum deposition apparatus, and Alq ₃ was formed to a thickness of 10 nm in the same manner as the organic EL element 1-1.

  Subsequently, lithium fluoride was formed to a thickness of 0.5 nm as an electron injection layer, and then 150 nm of aluminum was formed as a cathode to produce an organic EL element 2-1 having a light emitting region of 2 mm × 2 mm square.

  Each organic EL element after production was evaluated by covering the non-light emitting surface with a glass case and sealing with an epoxy adhesive.

<< Production of organic EL elements 2-2 to 2-10 >>
In the production of the organic EL element 2-1, the organic EL elements 2-2 to 2-10 were produced in the same manner except that the compound (F-1) and the compound (1) were changed as shown in Table 2. .

<< Evaluation of Organic EL Elements 2-1 to 2-10 >>
(efficiency)
As shown in FIGS. 3 and 4, the produced organic EL elements 2-1 to 2-10 were covered with a glass case and sealed with an epoxy-based adhesive, as described in Example 1. Thus, the efficiency of each element was evaluated. In addition, the value of efficiency was represented by the relative value when the measured value of the organic EL element 2-1 was 100.

(DS (dark spot))
The organic EL elements 2-1 to 2-10 after the evaluation of the above efficiency were continuously lit for 100 hours under a constant current condition of 2.5 mA / cm ² , and then the light emitting region was confirmed. Elements that were less than 2 were excluded according to the following rank evaluation.

  About the sample in which more than 1/2 of the light emitting region remained, a dark spot was measured by visual evaluation by 10 people extracted at random, and the following rank evaluation was performed.

×: The dark spot spreads more than 1/2 of the light emitting area. Δ: The number of people who confirmed the dark spot was 6 to 10. ○: The number of people confirmed the dark spot was 3 to 5. ◎: The dark spot was confirmed. When the number of people who have done is less than three, the practical ranks are ○ and ◎.

  The obtained results are shown in Table 2.

  From Table 2, it is clear that the device of the present invention exhibits high efficiency and produces less DS (dark spots) than the comparative device.

Example 4
<< Preparation of white light emitting element and white lighting device >>
On the glass substrate with ITO patterned to 20 mm × 20 mm as the anode, α-NPD was formed to a thickness of 25 nm as the hole injection / transport layer, and the compound (F-1) and the exemplified compound (3) D-34 was adjusted such that the deposition rate was 100: 5: 0.6, and a 40 nm thick light emitting layer was provided.

Next, 10 nm of BAlq was formed as a hole blocking layer, and then 40 nm of Alq ₃ was formed to provide an electron transport layer. Subsequently, lithium fluoride was formed to a thickness of 0.5 nm as an electron injection layer, and then 150 nm of aluminum was formed as a cathode. The non-light emitting surface was covered with a glass case and sealed with an epoxy adhesive.

  The flat lamp shown in FIGS. 3 and 4 was produced using this element. When this flat lamp was energized, it was found that almost white light was obtained and it could be used as a lighting device.

Example 5
<< Preparation of white light emitting element and white lighting device >>
70% pure poly (3,4-ethylenedioxythiophene) -polystyrene sulfonate (PEDOT / PSS, Bayer, Baytron P Al 4083) on the same substrate as the white light emitting device and white lighting device produced in Example 3 The solution diluted in (1) was spin-coated at 3000 rpm for 30 seconds and then dried to provide a hole transport layer having a thickness of 30 nm.

  Furthermore, this board | substrate with a positive hole transport layer was moved to nitrogen atmosphere, and a compound (F-3) (80 mg), D-34 (3 mg), exemplary compound (22) (5.0 mg), and exemplary compound (14) ( 1.5 mg) in 10 ml of toluene was spin-coated at 1000 rpm for 30 seconds, and then dried to obtain a light emitting layer.

Subsequently, this substrate was transferred to a vacuum deposition apparatus, and the compound (F-4) was 10 nm as the first electron transport layer at a vacuum degree of 4.0 × 10 ⁻⁴ Pa, and Alq ₃ was further used as the second electron transport layer. A film having a thickness of 20 nm was formed.

  Subsequently, lithium fluoride was formed to a thickness of 0.5 nm as an electron injection layer, and then 150 nm of aluminum was formed as a cathode. The non-light emitting surface was covered with a glass case and sealed with an epoxy adhesive.

  When the obtained element was energized, almost white light was obtained, and it was found that it could be used as a lighting device.

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

Claims (10)

A material for an organic electroluminescence device, which is a metal complex represented by the following general formula (1).

[Wherein, A represents a 5- or 6-membered aromatic hydrocarbon ring group, a group represented by the following general formula (2), or a 5-membered or 6-membered aromatic heterocyclic group; Represents a 6-membered aromatic heterocyclic group or a group represented by the following general formula (2), A and B, and A and M are bonded by a covalent bond, and B and M are coordinate bonds Are bound by. M represents a transition metal element belonging to Groups 8 to 10 in the periodic table, and L represents an arbitrary ligand capable of coordinating with M. m represents an integer of 1 to 3, and n represents an integer of 0 to 2. However, one group always contains one group represented by the following general formula (2). ]

[Wherein, Q1, Q3 and Q5 each represent a 6-membered aromatic hydrocarbon ring or a 6-membered aromatic heterocycle, and Q2 and Q4 each represent a cyclopentadiene ring or a 5-membered aromatic heterocycle. ]   The organic electroluminescent element material according to claim 1, comprising at least one group represented by the general formula (2) as a substituent of A or B in the general formula (1).   The organic electroluminescent element material according to claim 1 or 2, wherein Q2 and Q4 in the general formula (2) are each a 5-membered aromatic heterocyclic ring containing a nitrogen atom or an oxygen atom.   B of the said General formula (1) is a 5-membered nitrogen-containing aromatic heterocyclic ring, The organic electroluminescent element material as described in any one of Claims 1-3 characterized by the above-mentioned.   M of the said General formula (1) is platinum or iridium, The organic electroluminescent element material as described in any one of Claims 1-4 characterized by the above-mentioned.   An organic electroluminescent device comprising the material for an organic electroluminescent device according to claim 1.   The layer containing the organic electroluminescent element material according to any one of claims 1 to 5 is formed by a wet process, The organic electroluminescent element according to claim 6,   A display element comprising the organic electroluminescence element according to claim 6.   An illuminating device comprising the organic electroluminescence element according to claim 6.   A metal complex compound represented by the general formula (1) according to any one of claims 1 to 5.

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