JP5707665B2 - ORGANIC ELECTROLUMINESCENCE ELEMENT, LIGHTING DEVICE AND DISPLAY DEVICE HAVING THE ELEMENT - Google Patents

Description

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

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

  On the other hand, an organic EL element has a configuration in which a light emitting layer containing a compound that emits light is sandwiched between a cathode and an anode, and injects electrons and holes into the light emitting layer to recombine excitons. This is an element that emits light by utilizing the emission of light (fluorescence / phosphorescence) when this exciton is deactivated, and can emit light at a voltage of several volts to several tens of volts. Therefore, it has a wide viewing angle, high visibility, and since it is a thin-film type completely solid element, it has attracted attention from the viewpoints of space saving and portability.

  For the development of organic EL elements for practical application, M.M. A. Baldo et al. , Nature, 395, 151-154 (1998), since Princeton University reported on an organic EL device using phosphorescence emission from an excited triplet. A. Baldo et al. , Nature, 403, 17, 750-753 (2000), US Pat. No. 6,097,147, research on materials that exhibit phosphorescence at room temperature has become active.

  In addition, recently discovered organic EL devices that use phosphorescence can realize a luminous efficiency that is approximately four times that of previous devices that use fluorescence. Research and development of light-emitting element layer configurations and electrodes are performed all over the world.

  For example, S.M. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001), a number of compounds have been studied for synthesis centering on heavy metal complexes such as iridium complexes.

  Although this is a very high potential method, the organic EL device using phosphorescence emission is greatly different from the organic EL device using fluorescence emission, and the method for controlling the position of the emission center, particularly the emission layer, is particularly different. An important technical issue in capturing the efficiency and lifetime of the device is how to recombine inside to stably emit light.

  Therefore, in recent years, multilayer multilayer devices having a hole transport layer (located on the anode side of the light emitting layer) and an electron transport layer (located on the cathode side of the light emitting layer) adjacent to the light emitting layer are well known. (For example, refer to Patent Document 2).

  In particular, when using blue phosphorescence, since the blue phosphorescent material itself has a high T1, development of peripheral materials and precise control of the emission center are strongly demanded.

  In recent years, in a light emitting layer of an organic EL element using a phosphorescent light emitting material, a technique using a dibenzothiophene derivative as a host material (see, for example, Patent Document 1), a dibenzothiophene as a hole injection component and / or a light emitting component are used. A technique using a thiophene derivative or a dibenzofuran derivative (for example, see Patent Document 2) is disclosed.

  However, it is still insufficient from the viewpoint of providing an organic EL device having high luminous efficiency, low driving voltage, excellent heat resistance, raw storage stability, and long life, and is seeking a further solution. Has been.

  On the other hand, because of demands for large area, low cost, and high productivity, there is a great expectation for a wet method (also called wet process), and film formation can be performed at a lower temperature than film formation by a vacuum process. In addition, it is possible to reduce damage to the lower organic layer, and there is great expectation in terms of improving the light emission efficiency and the device life.

However, in order to realize wet film formation in an organic EL device using blue phosphorescence, particularly, an electron transport material is a problem. From a practical viewpoint, a currently known electron transport material is solution-stable. In terms of performance, driving voltage, etc., it is still insufficient, and it has been found that further improvement techniques are indispensable.
JP 2007-126403 A JP 2005-112765 A

  An object of the present invention is to provide an organic electroluminescence element having high luminous efficiency, low driving voltage, excellent heat resistance, raw storage stability, and long life, and an illumination device and a display device including the element. It is.

The above object of the present invention is Ru is achieved by the following configurations, but according to the specific invention, in the structure 1 below, as a constituting layer, the following formula having at least one pyridine ring as a partial structure (1 The organic electroluminescent element which has an electron carrying layer containing at least 1 type of compound represented by this is provided.

1. In an organic electroluminescence device in which a plurality of constituent layers including a light emitting layer are sandwiched between an anode and a cathode,
The constituent layer has an electron transporting layer containing at least one compound represented by the following general formula (1), at least one of the light emitting layers contains a phosphorescent organometallic complex, and A standard electrode potential of a metal ion (M ^{n +} ) / metal (M) system of an element belonging to Group 1 or Group 2 of the periodic table in the cathode or a constituent layer in contact with the cathode is −3 Vvs. An organic electroluminescence device comprising a metal or a metal compound of an element larger than SHE.

[Wherein, R _{1 to} R ₇ each represents a hydrogen atom or a substituent. A represents a phenyl group, or a substituted or unsubstituted aromatic heterocyclic group having a substituent. However, A contains at least one carbazole ring, azacarbazole ring, dibenzofuran ring or dibenzothiophene ring as a partial structure. ]
2. 2. The organic electroluminescence device according to 1 above, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (2).

[Wherein, R _{11 to} R ₁₇ each represent a hydrogen atom or a substituent, X represents —O—, —S—, or —N (R ₁₀ ) —, and R ₁₀ represents a hydrogen atom or a substituent. Represents. X _{11 to} X ₁₇ represent —C (R ₁₈ ) ═ or —N═, and R ₁₈ represents a hydrogen atom or a substituent. When a plurality of —C (R ₁₈ ) ═ are present, R ₁₈ may be the same or different. However, at least one of R _{10 to} R ₁₈ represents a substituent. ]
3. X in the general formula (2) represents —N (R ₁₀ ) —, R _{11 to} R ₁₄ , R ₁₆ and R ₁₇ each represent a hydrogen atom, and X ₁₁ , X ₁₂ , X _{14 to} X _17. Each represents —CH═ or —N═. 3. The organic electroluminescence device according to 2 above, wherein

4). X in the general formula (2) represents —O— or —S—, R _{11 to} R ₁₄ , R ₁₆ and R ₁₇ are each a hydrogen atom, and X ₁₁ , X ₁₂ , X _{14 to} X ₁₇ Each represents -CH =, 2. The organic electroluminescent device according to 2 above, wherein

  5. 2. The organic electroluminescence device according to 1 above, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (3).

[Wherein, R _{21 to} R ₂₇ each represent a hydrogen atom or a substituent. X _{21 to} X ₂₈ each represent —C (R ₂₈ ) ═ or —N═, and R ₂₈ represents a hydrogen atom or a substituent. When there are a plurality of —C (R ₂₈ ) ═, R ₂₈ may be the same or different. However, at least one of R _{21 to} R ₂₈ represents a substituent. ]
6). In the general formula (3), R _{21 to} R ₂₄ , R ₂₆ and R ₂₇ each represent a hydrogen atom, and X ₂₁ , X ₂₂ , X ₂₄ , X ₂₅ , X ₂₇ and X ₂₈ are each —CH═ or 6. The organic electroluminescence device as described in 5 above, wherein -N = is represented.

  7). 2. The organic electroluminescent device according to 1 above, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (4).

[Wherein R _{31 to} R ₃₇ each represents a hydrogen atom or a substituent. X _{31 to} X ₃₅ each represent —C (R ₃₈ ) ═ or —N═, and R ₃₈ represents a hydrogen atom or a substituent. Provided _that at least one of X 31 _{to X 35 are,} -C _{where R 38} represents a substituent _{(R 38)} is =. When there are a plurality of —C (R ₃₈ ) ═, R ₃₈ may be the same or different. ]
8). 8. The organic according to 7 above, wherein R _{31 to} R ₃₄ , R ₃₆ and R _{37 in the} general formula (4) each represent a hydrogen atom, and X ₃₃ represents —CH═ or —N═. Electroluminescence element.

  9. The compound represented by any one of the general formulas (1) to (4) has at least one pyridine ring or a condensed aromatic heterocyclic ring containing the pyridine ring as a partial structure. Organic electroluminescent element of any one of these.

  10. 10. The organic electroluminescence device according to any one of 1 to 9, wherein the element represents sodium, potassium, or cesium.

  11. 11. The organic electroluminescence device according to any one of 1 to 10, wherein at least one of the phosphorescent organometallic complexes is a compound represented by the following general formula (5).

[Wherein, P and Q each represent a carbon atom or a nitrogen atom, and A1 represents an atomic group which forms an aromatic hydrocarbon ring or an aromatic heterocycle together with PC. A2 represents an atomic group which forms an aromatic heterocycle with QN. P ₁ -L ₁ -P ₂ represents a bidentate ligand, and P ₁ and P ₂ each independently represent a carbon atom, a nitrogen atom, or an oxygen atom. L1 represents an atomic group forming a bidentate ligand together with P ₁ and P ₂ . j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M ₁ represents a group 8-10 metal element in the periodic table. ]
12 12. The organic electroluminescence device as described in 11 above, wherein the compound represented by the general formula (5) is a compound represented by the following general formula (6).

[Wherein Z represents a hydrocarbon ring group or a heterocyclic group. P and Q each represent a carbon atom or a nitrogen atom, and A1 represents an atomic group that forms an aromatic hydrocarbon ring or an aromatic heterocyclic ring together with PC. A3 is _{-C (R 01) = C (} R 02) -, - N = C (R 02) -, - C (R 01) = N- or -N = N-a _{represents, R 01,} R ₀₂ is , Each represents a hydrogen atom or a substituent. P ₁ -L ₁ -P ₂ represents a bidentate ligand, and P ₁ and P ₂ each independently represent a carbon atom, a nitrogen atom, or an oxygen atom. L1 represents an atomic group forming a bidentate ligand together with P ₁ and P ₂ . j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M ₁ represents a group 8-10 transition metal element in the periodic table. ]
13. 13. The organic electroluminescence device as described in 12 above, wherein the compound represented by the general formula (6) is a compound represented by the following general formula (7).

[Wherein R ₀₃ represents a substituent, R ₀₄ represents a hydrogen atom or a substituent, and a plurality of R ₀₄ may be bonded to each other to form a ring. n01 represents an integer of 1 to 4. R ₀₅ represents a hydrogen atom or a substituent, and a plurality of R ₀₅ may be bonded to each other to form a ring. n02 represents an integer of 1 to 2. R ₀₆ represents a hydrogen atom or a substituent, and may combine with each other to form a ring. n03 represents an integer of 1 to 4. Z1 represents an atomic group necessary for forming a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocycle together with C—C. Z2 represents an atomic group necessary for forming a hydrocarbon ring or a heterocyclic ring. P ₁ -L ₁ -P ₂ represents a bidentate ligand, and P ₁ and P ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L1 represents an atomic group forming a bidentate ligand together with P ₁ and P ₂ . j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M ₁ represents a group 8-10 transition metal element in the periodic table. R ₀₃ and R ₀₆ , R ₀₄ and R _06, and R ₀₅ and R ₀₆ may be bonded to each other to form a ring. ]
14 14. The organic electroluminescence device as described in 13 above, wherein the compound represented by the general formula (7) is a compound represented by the following general formula (8).

[Wherein R ₀₃ represents a substituent, R ₀₄ represents a hydrogen atom or a substituent, and a plurality of R ₀₄ may be bonded to each other to form a ring. n01 represents an integer of 1 to 4. R ₀₅ represents a hydrogen atom or a substituent, and a plurality of R ₀₅ may be bonded to each other to form a ring. n02 represents an integer of 1 to 2. R ₀₆ represents a hydrogen atom or a substituent, and may combine with each other to form a ring. n03 represents an integer of 1 to 3. R ₀₇ represents a substituent or a single bond. P ₁ -L ₁ -P ₂ represents a bidentate ligand, and P ₁ and P ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L1 represents an atomic group forming a bidentate ligand together with P ₁ and P ₂ . j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M ₁ represents a group 8-10 transition metal element in the periodic table. ]
15. The organic electroluminescent device according to any one of the 11 to 14 wherein M ₁ represents iridium.

  16. 16. The organic electroluminescent element according to any one of 1 to 15, wherein at least two organic layers including the electron transport layer and the light emitting layer are formed by a wet method.

  17. 17. The organic electroluminescence element according to any one of 1 to 16, which emits white light.

  18. An illuminating device comprising the organic electroluminescence element according to any one of 1 to 16 above.

  19. 17. A display device comprising the organic electroluminescence element according to any one of 1 to 16.

  According to the present invention, an organic electroluminescence device having high luminous efficiency, low driving voltage, excellent heat resistance and raw storage stability and a long lifetime can be provided.

  In addition, a display device and a lighting device including the organic electroluminescence element could be provided.

In the organic EL device of the present invention, by having the configuration according to any one of configurations 1 to 16, high luminous efficiency, low driving voltage, excellent in heat resistance and storability, and long life It was possible to provide an organic electroluminescence device. In addition, a display device and a lighting device including the organic electroluminescence element could be provided.

  Hereinafter, the detail of each component of the organic EL element of this invention is demonstrated sequentially.

  As a result of intensive research in order to achieve the above object, the present inventors have obtained the knowledge described in the following (a) to (d), and performed molecular design on the basis of the knowledge described above. By finding the compound represented by the formula (1) and using at least one compound represented by the general formula (1) according to the present invention for the electron transport layer of the organic EL device, the organic compound has high efficiency and long life. It has been found that an EL element can be obtained.

  (A) A nitrogen atom, an oxygen atom, or a sulfur atom larger than a carbon atom belonging to the second period of the periodic table is represented by the general formula (1) according to the present invention containing a sulfur atom in order to take a more stable charged state. It was found that dibenzothiophene derivatives such as these compounds are more stable when charged under storage and during storage.

  (B) Since the dibenzothiophene skeleton of the compound represented by the general formula (1) of the present invention has high planarity and a high glass transition temperature, heat resistance is improved, and stability over time at high temperature and high humidity. Was found to be improved.

  (C) The substitution position A in the compound represented by the general formula (1) is a position where the conjugate length is not extended, that is, a position capable of being linked to another skeleton while maintaining a high triplet energy (T1). Furthermore, since it is easier to introduce a substituent in the synthesis than the 4-position of the dibenzothiophene ring, it is suitable for mass production.

(D) Further, as an electron injection material, an alkali metal or an alkaline earth metal represented by lithium fluoride having a small work function is well known, but an electron transport material of a compound represented by the general formula (1) As a result of a detailed study by the present inventors on the combination with the above, the first group of the periodic table (also referred to as an element periodic table) is included in the cathode or a constituent layer in contact with the cathode (for example, a cathode buffer layer). Alternatively, the element belongs to Group 2, and the standard electrode potential of the M ^{n +} / M system is −3 Vvs. By using a metal of an element larger than SHE or a metal compound (including a complex or a salt) in combination, the organic EL element can be driven at a very low voltage while being highly efficient.

  The cathode relating to the organic EL element of the present invention and the constituent layer adjacent to the cathode will be described in detail later in the constituent layer of the organic EL element.

  This is because an element having a larger oxidation-reduction potential is easier to receive electrons than an element having a lower oxidation-reduction potential, and is thus easily reduced to a metal state. As a result, electrons are easily transported from the cathode to the electron transport layer through the metal, and it is possible to provide a high-efficiency, low-voltage organic electroluminescent device by using the dibenzothiophene derivative of the present invention in combination with an electron injection material. became.

  It should be noted that the organic EL element is composed of an anode, a cathode, and constituent layers sandwiched between the anode and the cathode (such as a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer). The organic layer) will be described in detail later.

  Hereinafter, the compound represented by the general formula (1) will be described.

<< Compound Represented by Formula (1) >>
In the general formula (1), examples of the substituents represented by R _{1 to} R ₇ are alkyl groups (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group). Octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group etc.), alkenyl group (eg, vinyl group, allyl group etc.), alkynyl group (eg, Ethynyl group, propargyl group, etc.), aromatic hydrocarbon group (aromatic hydrocarbon ring group, 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, indium Nyl group, pyrenyl group, biphenylyl group, etc.), aromatic heterocyclic group (for example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1, 2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, A quinolyl group, a benzofuryl group, a dibenzofuryl group, a benzothienyl group, a dibenzothienyl group, an indolyl group, a carbazolyl group, a carbolinyl group, a diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group is a nitrogen atom) ), Quinoxalinyl group, Ridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyl) Oxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (Eg, methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, For example, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, Phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group) , Dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, aceto Group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group ( For example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonyl) Amino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcal Nylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexyl) Aminocarbonyl group, octylaminocarbonyl group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido) Group, pentylureido group, cyclohexylureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridy Sulfinyl group (eg, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group) Group), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenyl) Sulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino) Group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom), fluorinated hydrocarbon Group (for example, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, Triphenylsilyl group, phenyldiethylsilyl group, etc.), phosphono group and the like.

  In addition, these substituents may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

  In the general formula (1), the phenyl group represented by A includes at least one carbazole ring, azacarbazole ring, dibenzofuran ring or dibenzothiophene ring as a partial structure.

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

Moreover, this partial structure may be unsubstituted or may have a substituent, and this substituent is synonymous with the substituent represented by R _{1 to} R ₇ in the general formula (1).

In the general formula (1), examples of the aromatic heterocyclic group represented by A include a pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, , 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, Thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (one of the carbon atoms constituting the carboline ring of the carbolinyl group) One is replaced by a nitrogen atom), a quinoxalinyl group, Ridajiniru group, triazinyl group, quinazolinyl group, and phthalazinyl group. These groups may be unsubstituted or may further have substituents represented by R _{1 to} R ₇ in the general formula (1).

  The aromatic heterocyclic group includes at least one carbazole ring, azacarbazole ring, dibenzofuran ring or dibenzothiophene ring as a partial structure.

  As a more preferable embodiment of the compound represented by the general formula (1) according to the present invention, a compound represented by any one of the above general formulas (2), (3) or (4) can be mentioned.

<< Compound Represented by Formula (2) >>
In the general formula (2), the substituents represented by R _{11 to} R ₁₇ have the same meanings as the substituents represented by R _{1 to} R ₇ in the general formula (1).

In —N (R ₁₀ ) — of X in the general formula (2), the substituent represented by R ₁₀ has the same definition as the substituent represented by each of R _{1 to} R ₇ in the general formula (1). .

In X _{11 to} X ₁₇ of the general formula (2), the substituent represented by R ₁₈ of —C (R ₁₈ ) ═ is the substituent represented by R _{1 to} R ₇ in the general formula (1). It is synonymous with.

  Moreover, also in the compound represented by General formula (2), the following 2 types of preferable aspects (a) and (b) are mentioned.

(A) X in the general formula (2) represents —N (R ₁₀ ) —, R _{11 to} R ₁₄ , R ₁₆ and R ₁₇ each represents a hydrogen atom, and X ₁₁ , X ₁₂ , X ₁₄ to When X ₁₇ represents -CH = or -N =,
(B) X in the general formula (2) represents —O— or —S—, R _{11 to} R ₁₄ , R ₁₆ and R ₁₇ are each a hydrogen atom, and X ₁₁ , X ₁₂ , X ₁₄ to When X ₁₇ each represents —CH═,
It is.

<< Compound Represented by Formula (3) >>
In the general formula (3), the substituents represented by R _{21 to} R ₂₇ have the same meaning as the substituents represented by R _{1 to} R ₇ in the general formula (1).

In —C (R ₂₈ ) ═ represented by X _{21 to} X ₂₈ in the general formula (3), the substituent represented by R ₂₈ is represented by R _{1 to} R ₇ in the general formula (1), respectively. It is synonymous with the substituent made.

  Moreover, also in the compound represented by General formula (3), as a preferable aspect, the aspect (c) as shown below is mentioned.

(C) R _{21 to} R ₂₄ , R ₂₆ and R _{27 in the} general formula (3) each represent a hydrogen atom, and X ₂₁ , X ₂₂ , X ₂₄ , X ₂₅ , X ₂₇ and X ₂₈ are each —CH = Or -N =
It is.

<< Compound Represented by Formula (4) >>
In the general formula (4), the substituents represented by R _{31 to} R ₃₇ have the same meaning as the substituents represented by R _{1 to} R ₇ in the general formula (1).

In —C (R ₃₈ ) ═ represented by X _{31 to} X ₃₅ in the general formula (4), the substituent represented by R ₃₈ is represented by R _{1 to} R ₇ in the general formula (1), respectively. It is synonymous with the substituent made.

  Moreover, also in the compound represented by General formula (4), as a preferable aspect, the aspect (d) shown below is mentioned.

(D) When R _{31 to} R ₃₄ , R ₃₆ , R _{37 in the} general formula (4) each represent a hydrogen atom, and X ₃₃ represents —CH═ or —N═,
It is.

  Hereinafter, further preferred embodiments of the compound represented by any one of the general formulas (1), (2), (3), and (4) according to the present invention will be described.

<< Preferred partial structure >>
Moreover, as a preferable aspect of the compound represented by any one of the general formulas (1), (2), (3) or (4) according to the present invention, a pyridine ring or a condensed aromatic heterocyclic ring containing the pyridine ring It is preferable to have at least one of the partial structures.

  Here, the condensed aromatic heterocyclic ring containing a pyridine ring refers to a condensed aromatic heterocyclic ring in which at least one of the rings constituting the condensed ring is a pyridine ring, such as β-carboline.

<< Tg (glass transition temperature ° C) >>
In order to increase the Tg (glass transition temperature ° C.) of the compound represented by any one of the general formulas (1), (2), (3) or (4) according to the present invention, a condensed ring such as a naphthalene ring or an anthracene ring Is effectively introduced into the compound.

  However, the condensed aromatic hydrocarbon ring has a small T1 (showing a triplet excited state or an excited triplet state), and is not particularly suitable for use simultaneously with a blue phosphorescent dopant.

  Therefore, it is preferable to introduce an aromatic heterocondensed ring such as a carbazole ring or a dibenzofuran ring as a means for improving Tg without lowering T1.

<< Constituent layer preferably contained and method for producing the constituent layer >>
The compound represented by any one of the general formulas (1), (2), (3) or (4) according to the present invention is contained in at least the electron transport layer, but a layer other than the electron transport layer, for example, holes It may be contained in the transport layer or the light emitting layer.

  As a method for producing a layer containing a compound represented by any one of the general formulas (1), (2), (3), or (4) according to the present invention, a wet method (also referred to as a wet process), a vapor deposition method, or the like. However, a wet method is preferably used from the viewpoint that a homogeneous film is easily obtained and pinholes are hardly generated.

  Here, as the wet method, there are a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, an ink jet method, a printing method, a spray coating method, a curtain coating method, etc., but a precise thin film can be formed. In view of high productivity, a method having high suitability for a roll-to-roll method such as a die coating method, a roll coating method, an ink jet method, or a spray coating method is preferable. Different film forming methods may be applied for each layer.

  Moreover, when forming a constituent layer by a coating method (including a dispersion method) using the compound represented by any one of the general formulas (1), (2), (3) or (4) according to the present invention, Although there is no restriction | limiting in the solvent to be used, It is preferable that the relationship between Tg of the said compound and the boiling point Tb of a solvent satisfies following formula (1).

Formula (1)
Tg + 10 ° C. ≧ Tb
In addition, it is preferable that three or more organic layers constituting the organic EL element of the present invention are formed by coating, and the cathode may be formed by coating using silver nanoparticles or the like.

  Hereinafter, although the specific example of the compound represented by either of general formula (1), (2), (3) or (4) which concerns on this invention is shown, this invention is not limited to these.

  The compounds represented by any one of the general formulas (1), (2), (3) or (4) according to the present invention are disclosed in WO 07/111176, Chem. Mater. It can be synthesized by referring to known methods described in 2008, 20, 5951, Experimental Chemistry Course 5th Edition (Edited by Chemical Society of Japan).

<< Compound Represented by Formula (5) >>
As the phosphorescent metal complex contained in the organic EL device of the present invention, a compound represented by the above general formula (5) is preferable.

  Hereinafter, the compound represented by Formula (5) will be described. Incidentally, the phosphorescent metal complex represented by the general formula (5) is a preferred embodiment that is contained as a light emitting dopant in the light emitting layer of the organic EL device of the present invention. (The constituent layers of the organic EL device of the present invention will be described in detail later).

  In the general formula (5), the aromatic hydrocarbon ring that A1 forms with P—C includes a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a chrysene ring, a naphthacene ring, Triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, Examples include a pyrene ring, a pyrantolen ring, and anthraanthrene ring.

These rings may further have a substituent represented by each of R _{1 to} R ₇ in the general formula (1).

  In the general formula (5), the aromatic heterocycle formed by A1 together with P—C includes a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, Benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, carbazole ring, azacarbazole A ring etc. are mentioned.

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

These rings may further have a substituent represented by each of R _{1 to} R ₇ in the general formula (1).

  In the general formula (5), the aromatic heterocycle formed by A2 together with QN includes an oxazole ring, an oxadiazole ring, an oxatriazole ring, an isoxazole ring, a tetrazole ring, a thiadiazole ring, a thiatriazole ring, Examples include a thiazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, a pyrazole ring, and a triazole ring.

These rings may further have a substituent represented by each of R _{1 to} R ₇ in the general formula (1).

Specific examples of the bidentate ligand represented by P ₁ -L ₁ -P ₂ in the general formula (5) include phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabol, acetylacetone, picoline An acid etc. are mentioned.

  In the general formula (5), j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, j1 + j2 represents 2 or 3, and j2 is preferably 0.

In the general formula (5), M ₁ is a transition metal element of Group 8 to Group 10 (also simply referred to as a transition metal) in the periodic table, and is preferably iridium.

<< Compound Represented by Formula (6) >>
Among the compounds represented by the general formula (5) according to the present invention, the compound represented by the general formula (6) is preferable.

  In the general formula (6), examples of the hydrocarbon ring group represented by Z include a non-aromatic hydrocarbon ring group and an aromatic hydrocarbon ring group, and examples of the non-aromatic hydrocarbon ring group include a cyclopropyl group. , Cyclopentyl group, cyclohexyl group and the like. These groups may be unsubstituted or have a substituent described later.

  Examples of the aromatic hydrocarbon ring group (also referred to as aromatic hydrocarbon group, aryl group, etc.) include, 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 and the like.

These groups may be unsubstituted or may have substituents represented by R _{1 to} R ₇ in the general formula (1).

  In the general formula (6), examples of the heterocyclic group represented by Z include a non-aromatic heterocyclic group and an aromatic heterocyclic group. Examples of the non-aromatic heterocyclic group include an epoxy ring and an aziridine group. Ring, thiirane ring, oxetane ring, azetidine ring, thietane ring, tetrahydrofuran ring, dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε- Caprolactam ring, piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, piperazine ring, morpholine ring, tetrahydropyran ring, 1,3-dioxane ring, 1,4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine Ring, thiomorpholine-1,1-dioxide And groups derived from a ring, a pyranose ring, a diazabicyclo [2,2,2] -octane ring, and the like.

These groups may be unsubstituted or may have substituents represented by R _{1 to} R ₇ in the general formula (1).

  Examples of the aromatic heterocyclic group include pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl). Group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group , Benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), quinoxalinyl Group, pyridazinyl group, triazinyl group, key Zoriniru group, phthalazinyl group, and the like.

These groups may be unsubstituted or may have substituents represented by R _{1 to} R ₇ in the general formula (1).

  Preferably, the group represented by Z is an aromatic hydrocarbon ring group or an aromatic heterocyclic group.

  Although the preferable example of Z in General formula (6) is given to the following, Z may be unsubstituted other than the following illustration, may have a substituent further, and is not limited to these examples. Note that * represents a bonding position.

  In the general formula (6), the aromatic hydrocarbon ring that A1 forms with P—C includes a benzene ring, a biphenyl ring, a naphthalene ring, an azulene ring, an anthracene ring, a phenanthrene ring, a pyrene ring, a chrysene ring, and a naphthacene ring. , Triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring , Pyrene ring, pyranthrene ring, anthraanthrene ring and the like.

These rings may further have a substituent represented by each of R _{1 to} R ₇ in the general formula (1).

  In the general formula (6), the aromatic heterocycle formed by A1 together with P—C includes a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, Benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, carbazole ring, carboline ring And azacarbazole ring.

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

These rings may further have a substituent represented by each of R _{1 to} R ₇ in the general formula (1).

In -C (R ₀₁ ) = C (R ₀₂ )-, -N = C (R ₀₂ )-, -C (R ₀₁ ) = N- represented by A3 in the general formula (6), R ₀₁ , The substituent represented by each of R ₀₂ has the same meaning as the substituent represented by each of R _{1 to} R ₇ in the general formula (1).

In the general formula (6), specific examples of the bidentate ligand represented by P ₁ -L ₁ -P ₂ include phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabol, acetylacetone, picoline An acid etc. are mentioned.

  J1 represents an integer of 1 to 3, and j2 represents an integer of 0 to 2, j1 + j2 represents 2 or 3, and j2 is preferably 0.

In the general formula (6), (also referred to simply as a transition metal) group 8-10 transition metal elements in the periodic table represented by M _1, the periodic in the general formula (5), represented by M ₁ It is synonymous with the transition metal element of Group 8-10 in the table.

<< Compound Represented by Formula (7) >>
One preferred embodiment of the compound represented by the general formula (6) is a compound represented by the general formula (7).

In the general formula (7), the substituents represented by R ₀₃ , R ₀₄ , R ₀₅ , and R ₀₆ are the same as the substituents represented by R _{1 to} R ₇ in the general formula (1). .

  In the general formula (7), examples of the 6-membered aromatic hydrocarbon ring formed by Z1 together with C—C include a benzene ring.

These rings may further have a substituent represented by each of R _{1 to} R ₇ in the general formula (1).

  In the general formula (7), examples of the 5- or 6-membered aromatic heterocycle formed by Z1 together with C—C include an oxazole ring, an oxadiazole ring, an oxatriazole ring, an isoxazole ring, a tetrazole ring, and a thiadiazole. And a ring, a thiatriazole ring, an isothiazole ring, a thiophene ring, a furan ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, a pyrazole ring, and a triazole ring.

These rings may further have a substituent represented by each of R _{1 to} R ₇ in the general formula (1).

In the general formula _(7), bidentate ligand represented by P 1 _{-L1-P 2} are the compounds of formula _(5), bidentate ligand represented by P 1 _{-L1-P 2} It is synonymous with.

In the general formula (7), transition metal elements of group 8-10 of the periodic table represented by _{M 1} are the compounds of formula (5), group 8-10 of the periodic table represented by _{M 1} It is synonymous with the transition metal element.

<< Compound Represented by Formula (8) >>
Furthermore, among the compounds represented by the general formula (7), the compounds represented by the general formula (8) are preferable.

In General Formula (8), the substituents represented by R ₀₃ , R ₀₄ , R ₀₅ , R ₀₆ , and R ₀₇ are the same as the substituents represented by R _{1 to} R ₇ in General Formula (1), respectively. It is synonymous.

In the general formula _(8), bidentate ligand represented by P 1 _{-L1-P 2} are the compounds of formula _(5), bidentate ligand represented by P 1 _{-L1-P 2} It is synonymous with.

In the general formula (8), a transition metal element of group 8-10 of the periodic table represented by _{M 1} are the compounds of formula (5), group 8-10 of the periodic table represented by _{M 1} It is synonymous with the transition metal element.

  The compounds represented by the general formula (5), (6), (7) or (8) according to the present invention are described in Eur. J. et al. Chem. 2005, 1637-1643 or the like, or a halogen compound corresponding to a nitrogen-containing ring compound or an imidazole compound is reacted, or the corresponding amine, glyoxal, and aldehyde described in SYNTHESIS 2003, 17, 2661-2666, or the like It can be synthesized by referring to the reaction of ammonium chloride with ammonium chloride.

  Hereinafter, specific examples of the compound (also referred to as a metal complex) represented by any one of the general formulas (5), (6), (7), and (8) according to the present invention will be given, but the present invention is limited to these. Not.

  These metal complexes are described in, for example, Organic Letter, vol. 16, 2579-2581 (2001), Inorganic Chemistry, Vol. 30, No. 8, 1685-1687 (1991), J. Am. Am. Chem. Soc. , 123, 4304 (2001), Inorganic Chemistry, Vol. 40, No. 7, 1704-1711 (2001), Inorganic Chemistry, Vol. 41, No. 12, 3055-3066 (2002) , New Journal of Chemistry. 26, 1171 (2002), European Journal of Organic Chemistry, Vol. 4, pages 695-709 (2004), and further synthesized by applying methods such as references described in these documents. it can.

  Below, the synthesis example of a typical compound is shown.

  << Synthesis of Exemplified Compound D-26 >>

  In a solution of 2-phenyl- (2,4,6-trimethylphenyl) -1H-imidazole, 18 g (0.06861 mol) dissolved in 350 ml of 2-ethoxyethanol under a nitrogen atmosphere, iridium chloride trihydrate, 8 0.1 g (0.02297 mol) and 100 ml of water were added and refluxed for 5 hours under a nitrogen atmosphere.

  The reaction solution was cooled, 500 ml of methanol was added, and the precipitated crystals were collected by filtration. The obtained crystals were further washed with methanol and dried to obtain 15.2 g (yield: 88.4%) of Complex A.

  Under a nitrogen atmosphere, 14.5 g (0.009662 mol) of complex A and 14.5 g of sodium carbonate were suspended in 350 ml of 2-ethoxyethanol. To this suspension, 3.9 g (0.03895 mol) of acetylacetone was added and refluxed for 2 hours under a nitrogen atmosphere.

  After cooling the reaction solution, sodium carbonate and inorganic salts were removed by filtration under reduced pressure. 1 L of water was added to the solid obtained after concentration of the solvent under reduced pressure to suspend it, and the solid was collected by filtration.

  The obtained crystals were further washed with a methanol / water = 1/1 mixed solution, and after drying, 14.7 g (yield 93.6%) of complex B was obtained.

  In a nitrogen atmosphere, complex B, 7.5 g (0.009214 mol) and 2-phenyl- (2,4,6-trimethylphenyl) -1H-imidazole, 6.0 g (0.02287 mol) were suspended in 400 ml of glycerin. Made cloudy. The reaction was completed at a reaction temperature of 150 to 160 ° C. for 2 hours under a nitrogen atmosphere, and when the disappearance of the complex B was confirmed, the reaction was terminated.

  The reaction solution was cooled, 500 ml of methanol was added, and the precipitated crystals were collected by filtration.

  The obtained crystals were further washed with methanol, and dried to obtain 7.1 g (yield 78.9%) of a crude product. This crude product was dissolved in a small amount of methylene chloride and purified by silica gel column chromatography to obtain 6.5 g (yield 72.2%) of Exemplified Compound D-26 (methylene chloride).

  The phosphorescence emission wavelength in the solution of Exemplified Compound D-26 measured using Hitachi F-4500 was 466 nm (in 2-methyltetrahydrofuran).

<< Constituent layers of organic EL elements >>
The constituent layers of the organic EL element of the present invention will be described. In this invention, although the preferable specific example of the layer structure of an organic EL element is shown below, this invention is not limited to these.

(I) Anode / light emitting layer unit / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer unit / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer unit / hole blocking Layer / electron transport layer / cathode (iv) anode / hole transport layer / light emitting layer unit / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) anode / anode buffer layer / hole transport layer / light emission Layer unit / hole blocking layer / electron transport layer / cathode buffer layer / cathode 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.

《Electron transport layer》
The compound represented by any one of the general formulas (1), (2), (3), or (4) according to the present invention is included in at least one electron transport layer that is a constituent layer of the organic EL device of the present invention. Although it is contained, it may be contained in other constituent layers (which will be described in detail later) of the organic EL device of the present invention.

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

  The electron transport layer only needs to have a function of transmitting electrons injected from the cathode to the light emitting layer. As a constituent material of the electron transport layer, any conventionally known compound may be selected and used in combination. Is possible.

  Examples of conventionally known materials used for the electron transport layer (hereinafter referred to as electron transport materials) include heterocyclic tetracarboxylic acid anhydrides such as nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, naphthalene perylene, Carbodiimide, fluorenylidenemethane derivative, anthraquinodimethane and anthrone derivative, oxadiazole derivative, carboline derivative, or at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom. And derivatives having a cyclic structure.

  Furthermore, in the oxadiazole derivative, a thiadiazole derivative in which the oxygen atom of the oxadiazole ring is substituted with a sulfur atom, and a quinoxaline derivative having a quinoxaline ring known as an electron-withdrawing group can also be used as an electron transport material.

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

  In addition, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), and the like, and the central metals of these metal complexes are In, Mg, Metal complexes replaced with Cu, Ca, Sn, Ga or Pb can also be used as the electron transport material.

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

  In addition, inorganic semiconductors such as n-type-Si and n-type-SiC can also be used as the electron transport material.

  The electron transport layer is made of an electron transport material such as a vacuum deposition method, a wet method (also referred to as a wet process, such as a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, an ink jet method, a printing method, or a spray method. The film is preferably formed by thinning by a coating method, a curtain coating method, an LB method (such as Langmuir Brodgett method)).

  The method for forming the constituent layers of the organic EL element will be described in detail in the section of the method for manufacturing the organic EL element.

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

  Hereinafter, although the specific example of the conventionally well-known compound (electron transport material) preferably used together for formation of the electron carrying layer of the white organic EL element of this invention is given, this invention is not limited to these.

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

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

  For the production of the light emitting layer, a light emitting dopant or host compound described later is used, for example, a vacuum deposition method, a wet method (also referred to as a wet process, for example, a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, It can be formed by forming a film by an ink jet method, a printing method, a spray coating method, a curtain coating method, an LB method (such as Langmuir Brodgett method). When the compound is used for the light emitting layer, it is preferably produced by a wet process.

  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, phosphorescent dopant group) or fluorescent dopant) compound and a light emitting host compound. Is preferred.

(Luminescent dopant compound)
A light-emitting dopant compound (also referred to as a light-emitting dopant) will be described.

  As the light-emitting dopant, a fluorescent dopant (also referred to as a fluorescent compound) or a phosphorescent dopant (also referred to as a phosphorescent emitter, a phosphorescent compound, a phosphorescent compound, or the like) can be used.

(Phosphorescent dopant (also called phosphorescent dopant))
The phosphorescent dopant 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 has a phosphorescence quantum yield of 25. Although it is defined as a compound of 0.01 or more at ° C., a preferable phosphorescence quantum yield is 0.1 or more.

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

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

  In the organic EL device of the present invention, at least one of the light-emitting layers contains a phosphorescent organometallic complex (also referred to as a phosphorescent dopant or a phosphorescent dopant). Preferably contains a compound represented by any one of the general formulas (5), (6), (7) or (8) according to the present invention.

Furthermore, in the compound represented by any one of the general formulas (5), (6), (7) or (8) according to the present invention, M ₁ represents a transition metal element of Group 8 to Group 10 in the periodic table. Of these, iridium is preferred.

  Moreover, you may use together the compound etc. which are described in the following patent gazettes in the light emitting layer which concerns on this invention.

  For example, International Publication No. 00/70655 pamphlet, Japanese Patent Application Laid-Open No. 2002-280178, Japanese Patent Application Laid-Open No. 2001-181616, Japanese Patent Application Laid-Open No. 2002-280179, Japanese Patent Application Laid-Open No. 2001-181617, and Japanese Patent Application Laid-Open No. 2002-280180. JP, 2001-247859, JP, 2002-299060, JP, 2001-313178, JP, 2002-302671, JP, 2001-345183, JP, 2002-324679, International, Publication No. 02/15645, JP 2002-332291 A, JP 2002-50484 A, JP 2002-332292 A, JP 2002-83684 A, JP 2002-540572 A, JP 2002-117978, JP 2002-338588, JP 2002-170684, JP 2002-352960, WO 01/93642, JP 2002-50483, JP 2002-1000047, JP JP 2002-173684 A, JP 2002-359082 A, JP 2002-17584 A, JP 2002-363552 A, JP 2002-184582 A, JP 2003-7469 A, Special Table 2002. No. 525808, JP 2003-7471, JP 2002-525833, JP 2003-31366, JP 2002-226495, JP 2002-234894, JP 2002-233506 Japanese Patent Laid-Open No. 2002-24175 JP, JP 2001-319779, JP 2001-319780, JP 2002-62824, JP 2002-1000047, JP 2002-203679, 2002-343572. JP-A-2002-203678.

(Fluorescent dopant (also called fluorescent compound))
As fluorescent dopants, coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes, stilbene dyes , Polythiophene dyes, rare earth complex phosphors, and the like, and compounds having a high fluorescence quantum yield such as laser dyes.

  In addition, the light-emitting dopant according to the present invention may be used in combination of a plurality of types of compounds, or may be a combination of phosphorescent dopants having different structures, or a combination of a phosphorescent dopant and a fluorescent dopant.

(Luminescent host compound (also referred to as luminescent host))
In the present invention, the host compound has a mass ratio of 20% or more among the compounds contained in the light emitting layer, and a phosphorescence quantum yield of phosphorescence emission is 0 at room temperature (25 ° C.). Defined as less than 1 compound. The phosphorescence quantum yield is preferably less than 0.01. Moreover, it is preferable that the mass ratio in the layer is 20% or more among the compounds contained in a light emitting layer.

  There is no restriction | limiting in particular as a light emission host which can be used for this invention, The compound conventionally used with an organic EL element can be used. Typically, a carbazole derivative, a triarylamine derivative, an aromatic derivative, a nitrogen-containing heterocyclic compound, a thiophene derivative, a furan derivative, an oligoarylene compound or the like having a basic skeleton, or a carboline derivative or a diazacarbazole derivative (here And the diazacarbazole derivative represents one in which at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom.

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

  In the present invention, (the light emitting host of the present invention and / or a known light emitting host) may be used alone or in combination of two or more.

  By using a plurality of types of light-emitting hosts, the movement of charges can be adjusted, and the organic EL element can be made highly efficient.

  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.

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

  Specific examples of the known light-emitting host include 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.

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

"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.

<< Injection layer: electron injection layer (cathode buffer layer), hole injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer and between the cathode and the light emitting layer or the electron transport layer. May be.

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

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

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 5 μm although it depends on the material.

In the organic EL device of the present invention, the above-described cathode or a constituent layer in contact with the cathode (for example, an electron injection layer (cathode buffer layer)) is an element belonging to Group 1 or Group 2 of the periodic table, The standard electrode potential of elemental metal ion (M ^{n +} ) / metal (M) system is −3 Vvs. It is characterized by containing a metal or metal compound of an element larger than SHE.

Here, the standard electrode potential E ° of the M ^{n +} / M system according to the present invention is an electrode potential with respect to the standard hydrogen electrode in an aqueous solution having a temperature of 25 ° C. and an solute activity of all 1. For example, “Revision No. 3 You can refer to the values in Tables 12 and 46 of II-474 of “Chemical Handbook Basic Edition II” (The Chemical Society of Japan).

According to the present invention, the element belongs to Group 1 or Group 2 of the periodic table, and the standard electrode potential of the metal ion (M ^{n +} ) / metal (M) system of the element is −3 Vvs. Specific examples of the element constituting the metal or metal compound of an element larger than SHE include K (-2.925 (V)), Ca (-2.840 (V)), Na (-2.714). (V)), Mg (-2.356 (V)) and the like.

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

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

  Moreover, the structure of the 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 includes a carbazole derivative, a carboline derivative, a diazacarbazole derivative (the diazacarbazole derivative is a nitrogen atom in which any one of carbon atoms constituting the carboline ring is mentioned as the host compound described above. It is preferable to contain (represented by).

  In the present invention, when a plurality of light emitting layers having different light emission colors are provided, the light emitting layer having the shortest wavelength of light emission is preferably closest to the anode among all the light emitting layers. In this case, it is preferable to additionally provide a hole blocking layer between the shortest wave layer and the light emitting layer next to the anode next to the anode. Furthermore, it is preferable that 50% by mass or more of the compound contained in the hole blocking layer provided at the position has an ionization potential of 0.3 eV or more larger than the host compound of the shortest wave emitting layer.

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

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

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

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

  Moreover, the structure of the 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 transport 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, and in a broad sense, a hole injection layer and an electron blocking layer are also included in the hole transport layer. The hole transport layer can be provided as a single layer or a plurality of layers.

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

  The above-mentioned materials can be used as the hole transport material, but it is preferable to use a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, particularly an aromatic tertiary amine compound.

  Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ', N'-tetraphenyl-4,4'-diaminophenyl; N, N'-diphenyl-N, N'- Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' − (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl; N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino- (2-diphenylvinyl) benzene; 3-methoxy-4′-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and also two of those described in US Pat. No. 5,061,569. Having a condensed aromatic ring in the molecule, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-3086 4,4 ', 4 "-tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 8 are linked in a starburst type ( MTDATA) and the like.

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

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

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

  The hole transport layer can be formed by thinning the hole transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. it can.

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

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

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

  Hereinafter, although the specific example of the compound preferably used for formation of the positive hole transport layer of the organic EL element of this invention is given, this invention is not limited to these.

"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, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material.

  Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used. When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 nm to 1000 nm, preferably 10 nm to 200 nm.

《Support substrate》
As a 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, there is no particular limitation on the type of glass, plastic, etc., and it is transparent. May be opaque. When extracting light from the support substrate side, the support substrate is preferably transparent. Examples of the transparent support substrate preferably used include glass, quartz, and a transparent resin film. A particularly preferable support substrate is a resin film capable of giving flexibility to the organic EL element.

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

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. A high barrier film having a permeability of 10 ⁻³ ml / (m ² · 24 h · atm) or less and a water vapor permeability of 10 ⁻⁵ g / (m ² · 24 h) or less is preferable.

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

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

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

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

  Here, the external extraction quantum efficiency (%) = the number of photons emitted to the outside of the organic EL element / the number of electrons sent to the organic EL element × 100.

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

<< Method for Manufacturing Organic EL Element >>
As an example of a method for producing an organic EL device, a device comprising an anode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer (electron injection layer) / cathode Will be described.

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

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

  In the phosphorescent organic EL device of the present invention, at least the cathode and the electron transport layer adjacent to the cathode are applied and formed by a wet method.

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

  Examples of the liquid medium for dissolving or dispersing the organic EL material according to the present invention include ketones such as methyl ethyl ketone and cyclohexanone, fatty acid esters such as ethyl acetate, halogenated hydrocarbons such as dichlorobenzene, toluene, xylene, and mesitylene. Aromatic hydrocarbons such as cyclohexylbenzene, aliphatic hydrocarbons such as cyclohexane, decalin, and dodecane, and organic solvents such as 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 the formation of these layers, a thin film made of a cathode material is formed thereon so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and a desired organic EL device can be obtained by providing a cathode. .

  Further, the order can be reversed, and the cathode, cathode buffer layer, electron transport layer, hole blocking layer, light emitting layer, hole transport layer, hole injection layer, and anode can be formed in this order.

  When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 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.

  The organic EL device of the present invention is preferably produced from the hole injection layer to the cathode consistently by a single evacuation, but may be taken out halfway and subjected to different film forming methods. At that time, it is preferable to perform the work in a dry inert gas atmosphere.

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

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

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

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

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

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

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

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

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

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

  Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials. The method for forming these films is not particularly limited. For example, vacuum deposition, sputtering, reactive sputtering, molecular beam epitaxy, cluster-ion beam method, ion plating method, plasma polymerization method, atmospheric pressure plasma A polymerization method, a plasma CVD method, a laser CVD method, a thermal CVD method, a coating method, or the like can be used.

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

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

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

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

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

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

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

  When a medium 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 and second-order diffraction. Light that cannot be emitted due to total internal reflection between layers is diffracted by introducing a diffraction grating in any layer or medium (in a transparent substrate or transparent electrode), and the light is removed. I want to take it out.

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

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

  As described above, the position where the diffraction grating is introduced may be in any of the layers or in the medium (in the transparent substrate or 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 is processed on the light extraction side of the substrate so as to provide, for example, a microlens array structure, or combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the device light emitting surface. By condensing in the front direction, the luminance in a specific direction can be increased.

  As an example of the microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are 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.

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

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

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

Further, when the organic EL element of the present invention is a white element, white means that the chromaticity in the CIE 1931 color system at 1000 cd / m ² is X when the 2 ° viewing angle front luminance is measured by the above method. = 0.33 ± 0.07 and Y = 0.33 ± 0.1.

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

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

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

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

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

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

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

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

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

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

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

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

  FIG. 5 shows a schematic diagram of a lighting device, and the organic EL element 101 of the present invention is covered with a glass cover 102 (in the sealing operation with the glass cover, the organic EL element 101 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).

  FIG. 6 shows a cross-sectional view of the lighting device. In FIG. 6, 105 denotes a cathode, 106 denotes an organic EL layer, and 107 denotes a glass substrate with a transparent electrode. The glass cover 102 is filled with nitrogen gas 108 and a water catching agent 109 is provided.

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

  Moreover, the structure of the compound used for an Example is shown below.

Example 1
<< Production of Organic EL Element 1-1 >>
After patterning on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a 100 mm × 100 mm × 1.1 mm glass substrate as an anode, this ITO transparent electrode was provided. The transparent support substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

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

  This substrate was transferred to a nitrogen atmosphere, and a solution prepared by dissolving 50 mg of the hole transport material 1 in 10 ml of toluene was spin-coated on the hole transport layer on the hole transport layer under conditions of 1500 rpm and 30 seconds to form a thin film. Formed. Further, ultraviolet light was irradiated for 180 seconds to carry out photopolymerization and crosslinking, thereby forming a second hole transport layer having a thickness of about 20 nm.

  On this second hole transport layer, a thin film was formed by spin coating using a solution of 100 mg Host-24 and 10 mg D-1 dissolved in 10 ml toluene at 600 rpm for 30 seconds. It vacuum-dried at 60 degreeC for 1 hour, and was set as the light emitting layer with a film thickness of about 70 nm.

  Next, a thin film was formed on this light emitting layer by spin coating using a solution of 50 mg of electron transport compound 1 dissolved in 10 ml of hexafluoroisopropanol (HFIP) at 1000 rpm for 30 seconds. Furthermore, it vacuum-dried at 60 degreeC for 1 hour, and was set as the electron carrying layer with a film thickness of about 30 nm.

Subsequently, this substrate was fixed to a substrate holder of a vacuum deposition apparatus, and after the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa, sodium fluoride was deposited at 0.4 nm as a cathode buffer layer, and aluminum was deposited at 110 nm as a cathode. Thus, a cathode was formed, and an organic EL element 1-1 was produced.

<< Production of Organic EL Elements 1-2 to 1-4 >>
In the production of the organic EL device 1-1, organic EL devices 1-2 to 1-4 were produced in the same manner except that the electron transport compound 1 was changed to the following compound.

<< Evaluation of Organic EL Elements 1-1 to 1-4 >>
When evaluating the obtained organic EL elements 1-1 to 1-4, the specific light emitting surface of each organic EL element after production is covered with a glass cover, and the glass cover and the glass substrate on which the organic EL element is produced are prepared. An epoxy-based photo-curing adhesive (Luxtrac LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealant around the glass cover side that comes into contact with the transparent support substrate so as to overlap the cathode side, and the glass substrate side. Then, it was cured by irradiating with UV light and sealed, and the lighting device as shown in FIGS. 5 and 6 was formed and evaluated. Next, storage stability was evaluated according to the following measurement method.

(Stability over time)
After each organic EL element was stored at 85 ° C. for 24 hours, each brightness at a constant current drive of ^2.5 mA / cm ² before and after storage was measured, and each brightness ratio was determined according to the following formula. A scale.

Stability over time (%) = luminance after storage ( ^2.5 mA / cm ² ) / luminance before storage ( ^2.5 mA / cm ² ) × 100
The results obtained are shown below.

Organic EL device Electron transport material Stability over time Remarks
(%)
1-1 Electron Transport Compound 1 47 Comparative Example 1-2 39 68 Reference Example 1-3 38 76 Reference Example 1-4 1 83 Reference Example From the above, the organic EL device of the present invention is more stable over time than the comparative device. It is clear that the property (storability) is excellent.

Example 2
<< Preparation of Organic EL Element 2-1 >>
Transparent support provided with this ITO transparent electrode after patterning on a substrate (NH45 manufactured by NH Techno Glass) made of ITO (indium tin oxide) with a thickness of 100 nm on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode The substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum deposition apparatus, while 200 mg of hole transport material 2 (NPD) is put in a molybdenum resistance heating boat, and Host-34 is used as a host compound in another molybdenum resistance heating boat. 200 mg, D-25 was placed in another molybdenum resistance heating boat, and the electron transport compound 2 was placed in another molybdenum resistance heating boat, and attached to a vacuum deposition apparatus.

Next, after the pressure in the vacuum chamber is reduced to 4 × 10 ⁻⁴ Pa, the heating boat containing the hole transport material 2 is energized and heated, and deposited on the transparent support substrate at a deposition rate of 0.1 nm / second. A hole transport layer was provided.

  Furthermore, the heating boat containing Host-34 and D-25 was heated by energization, and co-evaporated on the hole transport layer at a deposition rate of 0.2 nm / second and 0.012 nm / second, respectively, to form a light emitting layer. Provided. In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Furthermore, the heating boat containing the electron transport compound 2 was energized and heated, and deposited on the light emitting layer at a deposition rate of 0.1 nm / second to provide an electron transport layer. In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Subsequently, 0.5 nm of potassium fluoride and 110 nm of aluminum were vapor-deposited to form a cathode, and an organic EL element 2-1 was produced.

  In the production of the organic EL element 2-1, organic EL elements 2-2 to 2-4 were produced in the same manner except that the electron transport compound 2 was changed to the following compound.

<< Evaluation of Organic EL Elements 2-1 to 2-4 >>
When evaluating the obtained organic EL elements 2-1 to 2-4, they were sealed in the same manner as the organic EL elements 1-1 to 1-4 of Example 1, and illumination as shown in FIGS. A device was formed and evaluated.

  The organic EL element obtained as follows was evaluated.

<Stability over time>
After storing the organic EL element at 60 ° C. and 70% RH for one month, each brightness was measured with a constant current drive of ^2.5 mA / cm ² before and after storage in the same manner as in Example 1, and the brightness ratio was reduced. It was determined according to the formula and was used as a measure of stability over time.

Stability over time (%) = luminance after storage ( ^2.5 mA / cm ² ) / luminance before storage ( ^2.5 mA / cm ² ) × 100
The obtained results are shown below.

Organic EL device Electron transport material Stability over time Remarks
(%)
2-1 Electron Transport Compound 2 40 Comparative Example 2-2 41 65 Reference Example 2-3 40 71 Reference Example 2-4 36 78 Present Invention From the above, the organic EL device of the present invention is more stable over time than the comparative device. It is clear that the property (storability) is excellent.

Example 3
<< Production of Organic EL Element 3-1 >>
Transparent support provided with this ITO transparent electrode after patterning on a substrate (NH45 manufactured by NH Techno Glass) made of ITO (indium tin oxide) with a thickness of 100 nm on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode The substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

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

  This transparent support substrate is fixed to a substrate holder of a commercially available vacuum evaporation apparatus, while 200 mg of hole transport material 2 (NPD) is put in a molybdenum resistance heating boat, and Host-30 as a host compound in another resistance heating boat made of molybdenum. 200 mg, D-26 was put into another molybdenum resistance heating boat, and the electron transport compound 3 was put into another molybdenum resistance heating boat, and attached to a vacuum deposition apparatus.

Then, after reducing the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing the hole transport material 2 is heated by heating, and deposited on the hole transport layer at a deposition rate of 0.1 nm / second, A hole transport layer 2 was provided.

  Further, the heating boat containing Host-30 and D-26 was energized and heated, and co-evaporated on the hole transport layer 2 at a deposition rate of 0.2 nm / second and 0.012 nm / second, respectively, to emit light. A layer was provided.

  In addition, the substrate temperature at the time of vapor deposition was room temperature. Further, the heating boat containing the electron transport compound 3 was energized and heated, and deposited on the light emitting layer at a deposition rate of 0.1 nm / second to provide an electron transport layer.

  In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Subsequently, 0.5 nm of potassium fluoride and 110 nm of aluminum were vapor-deposited to form a cathode, and an organic EL element 3-1 was produced.

<< Production of Organic EL Elements 3-2 to 3-4 >>
In the production of the organic EL element 3-1, organic EL elements 3-2- to 3-4 were produced in the same manner except that the electron transport compound 3 was changed to the following compound.

<< Evaluation of Organic EL Elements 3-1 to 3-4 >>
When evaluating the obtained organic EL elements 3-1 to 3-4, sealing was performed in the same manner as the organic EL elements 1-1 to 1-4 to form an illumination device as shown in FIGS. And evaluated.

  Evaluation of the obtained organic EL element was performed as follows.

(External quantum efficiency)
By causing the organic EL element to emit light at a constant current of ^2.5 mA / cm ² at room temperature (about 23 ° C. to 25 ° C.) and measuring the light emission luminance (L) [cd / m ² ] immediately after the start of light emission. The external extraction quantum efficiency (η) was calculated.

  Here, CS-1000 (manufactured by Konica Minolta Sensing) was used for measurement of light emission luminance. The external extraction quantum efficiency was expressed as a relative value with the organic EL element 3-1 as 100.

(Luminescent life)
The organic EL device continuously emitted light at room temperature under a constant current condition of ^2.5 mA / cm ² , and the time (τ ^1/2 ) required to reach half the initial luminance was measured. The light emission lifetime was expressed as a relative value at which the organic EL element 3-1 was set to 100.

  The results obtained are shown below.

Organic EL device Electron transport material External extraction Life Remarks
Quantum efficiency (%)
3-1 Electron Transport Compound 3 100 100 Comparative Example 3-2 42 125 350 Reference Example 3-3 43 123 410 Reference Example 3-4 27 128 520 Present Invention From the above, the organic EL of the present invention compared to the comparative device It is clear that the device has a high external extraction quantum efficiency and a long lifetime.

Example 4
<< Preparation of Organic EL Element 4-1 >>
In preparation of the organic EL element 1-1, instead of the hole transport material 1, a mixed solution in which 5 mg of the hole transport material 3 and 45 mg of the hole transport material 4 are dissolved in 10 ml of toluene is used. Organic EL element 4-1 was produced in the same manner except that Host-25 was used instead of D-1, D-30 was used instead of D-1, and BCP was used instead of electron transport compound 1.

<< Production of Organic EL Elements 4-2 to 4-5 >>
In the production of the organic EL element 4-1, organic EL elements 4-1 to 4-5 were produced in the same manner except that BCP was changed to the following compound.

<< Evaluation of Organic EL Elements 4-1 to 4-5 >>
When evaluating the obtained organic EL elements 4-1 to 4-5, sealing was performed in the same manner as the organic EL elements 1-1 to 1-4, and an illumination device as shown in FIGS. 5 and 6 was formed. And evaluated.

  Evaluation of the obtained organic EL element was performed as follows.

(Luminance brightness)
The light emission luminance (cd / m ² ) when a 4 V DC voltage was applied to the organic EL element at room temperature (about 23 to 25 ° C.) was measured.

(External quantum efficiency)
The external extraction quantum efficiency under a constant current condition of ^2.5 mA / cm ² was determined in the same manner as in the case of the organic EL elements 3-1 to 3-4 of Example 3.

  In the evaluation, the light emission luminance and the external extraction quantum efficiency are expressed as relative values with the organic EL element 4-1 as 100.

(Voltage increase rate)
When driving at a constant current of 6 mA / cm ² , the initial voltage and the voltage after 150 hours were measured. The relative value of the voltage after 100 hours with respect to the initial voltage was defined as the voltage increase rate.

  The results obtained are shown below.

Organic EL Electron Transport Property External Extraction Lifetime Voltage Remarks Element Material Quantum Efficiency (%) Increase Rate 4-1 BCP 100 100 122 Comparative Example 4-2 Electron Transport Compound 4 114 164 120 Comparative Example 4-3 44 124 390 115 Reference Example 4 -4 45 126 430 113 The present invention 4-5 29 '132 570 113 The present invention From the above, the organic EL device of the present invention has a higher external extraction quantum efficiency, longer life, and higher voltage than the comparative device. It is clear that the rate is also low.

Example 5
<< Production of Organic EL Element 5-1 >>
In the production of the organic EL device 1-1, Host-24 is replaced with Host-9, D-1 is replaced with D-24, the electron transport compound 1 is replaced with the electron transport compound 5, and a fluorine is used instead of sodium fluoride. An organic EL device 5-1 was produced in the same manner except that lithium fluoride was used.

<< Production of organic EL elements 5-2 to 5-5 >>
In the production of the organic EL element 5-1, organic EL elements 5-2 to 5-5 were produced in the same manner except that lithium fluoride and the electron transport compound 5 were replaced with the following compounds.

<< Evaluation of Organic EL Elements 5-1, 5-2 >>
When evaluating the obtained organic EL elements 5-1 to 5-5, sealing was performed in the same manner as the organic EL elements 1-1 to 1-4, and an illumination device as shown in FIGS. 5 and 6 was formed. And evaluated.

About the produced element, it carried out similarly to the organic EL element 3-1 to 3-4 of Example 3, and calculated | required the part extraction quantum efficiency and voltage in ^2.5 mA / cm < ² > constant current conditions.

  In addition, in the evaluation, the result of the organic EL element 5-1 was expressed as a relative value with 100.

Organic EL Electron Transport Electron Injection Layer External Extraction Voltage Remarks Element Material Quantum Efficiency (%) Increase Rate 5-1 Electron Transport Compound 5 LiF 100 100 Comparative Example 5-2 46 LiF 108 91 Comparative Example 5-3 Electron Transport Compound 5 KF 105 62 Comparative Example 5-4 46 KF 115 47 Present Invention 5-5 2 KF 117 44 Present Invention Note that the standard electrode potentials of the metal elements constituting LiF and KF used for forming the electron injection layer are as follows. Show.

Li -3.045 (V): Comparative Example K -2.925 (V): Present Invention From the above, the organic EL device of the present invention has higher external extraction quantum efficiency and higher voltage than the comparative device. It is clear that the rate is also low.

Example 6
<< Production of Organic EL Element 6-1 >>
In the production of the organic EL element 3-1, the organic material was changed in the same manner except that Host-30 was replaced with Host-25, D-26 was replaced with D-9, and the electron transport compound 3 was replaced with the electron transport compound 6. An EL element 6-1 was produced.

<< Production of Organic EL Elements 6-2 to 6-4 >>
Organic EL elements 6-2 to 6-4 were prepared in the same manner as in the preparation of the organic EL element 6-1, except that D-9 and the electron transport compound 6 were replaced with the following compounds.

<< Evaluation of Organic EL Elements 6-1 to 6-4 >>
When evaluating the obtained organic EL elements 6-1 to 6-4, sealing was performed in the same manner as the organic EL elements 1-1 to 1-4, and an illumination device as shown in FIGS. 5 and 6 was formed. And evaluated.

For the fabricated devices was determined external extraction quantum efficiency and emission lifetime in the constant current condition of 2.5 mA / cm ² in the same manner as the organic EL element 3-1 to 3-4 of Example 3.

Moreover, the luminescent color at the time of performing continuous light emission on ^2.5 mA / cm < ² > constant current conditions was evaluated visually. Each of the results of the organic EL element 5-1 was represented by a relative value of 100.

  The results obtained are shown below.

Organic EL dopant Electron transport property External extraction Lifetime Luminescent color Remarks Element Material Quantum efficiency (%)
6-1 D-9 Electron Transport Compound 6 100 100 Blue Comparative Example 6-2 D-9 24 107 130 Blue Present Invention 6-3 D-24 24 112 740 Blue Present Invention 6-4 D-26 24 121 5000 Blue Present Invention From the above, it was found that the organic EL device of the present invention has a high external extraction quantum efficiency and a long lifetime as compared with the comparison.

Example 7
<< Production of Organic EL Element 7-1 >>
In the production of the organic EL device 1-1, organic matter was similarly obtained except that Host-24 was replaced with Host-16, D-1 was replaced with D-10, and the electron transport compound 1 was replaced with the electron transport compound 7. An EL element 7-1 was produced.

<< Preparation of organic EL elements 7-2 to 7-3 >>
In the production of the organic EL element 7-1, organic EL elements 7-2 to 7-3 were produced in the same manner except that the host compound and the electron transporting material were replaced with the following compounds.

<< Evaluation of Organic EL Elements 7-1 to 7-3 >>
When evaluating the obtained organic EL elements 7-1 to 7-3, sealing was performed in the same manner as the organic EL elements 1-1 to 1-4, and an illumination device as shown in FIGS. 5 and 6 was formed. And evaluated.

About the produced element, it carried out similarly to the organic EL element 3-1 to 3-4 of Example 3, and calculated | required the part extraction quantum efficiency and the light emission lifetime in ^2.5 mA / cm < ² > constant current conditions.

  In the evaluation, the organic EL element 5-1 was expressed as a relative value with an evaluation of 100.

  The results obtained are shown below.

Organic EL Host Electron transport property External extraction Life Remarks Element Compound Material Quantum efficiency (%)
7-1 Host-16 Electron Transport Compound 7 100 100 Comparative Example 7-2 Host-16 37 133 320 Reference Example 7-3 Host-15 37 130 700 Reference Example From the above, compared to the comparison, the organic EL device of the present invention Was found to have a high external extraction quantum efficiency and a long lifetime.

Example 8 (Production of white element)
<< Production of organic EL full-color display device >>
FIG. 7 shows a schematic configuration diagram of an organic EL full-color display device. After patterning at a pitch of 100 μm on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) having a 100 nm thick ITO transparent electrode (202) formed on a glass substrate 201 as an anode, non-between the ITO transparent electrodes on this glass substrate. A photosensitive polyimide partition 203 (width 20 μm, thickness 2.0 μm) was formed by photolithography.

  A hole injection layer composition having the following composition was ejected and injected between polyimide partition walls on the ITO electrode using an inkjet head (manufactured by Epson Corporation; MJ800C), irradiated with ultraviolet light for 150 seconds, and dried at 60 ° C. for 10 minutes. A hole injection layer 204 having a thickness of 40 nm was produced by the treatment.

  On the hole injection layer, the following blue light-emitting layer composition, green light-emitting layer composition, and red light-emitting layer composition were similarly discharged and injected using an inkjet head, and dried at 60 ° C. for 10 minutes. Each light emitting layer (205B, 205G, 205R) was formed.

  Next, Compound Example 25 was vapor-deposited to a thickness of 20 nm on the light-emitting layer, and sodium fluoride was 0.6 nm, and Al (106) was vacuum-deposited as a cathode at 130 nm to produce an organic EL device.

  It was found that the produced organic EL element showed blue, green, and red light emission by applying a voltage to each electrode, and could be used as a full-color display device.

(Hole injection layer composition)
Hole transport material 5 20 parts by mass Cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (Blue light emitting layer composition)
Host-9 0.7 parts by mass D-26 0.04 parts by mass Cyclohexylbenzene 50 parts by mass Isopropyl biphenyl 50 parts by mass (green light emitting layer composition)
Host-9 0.7 parts by mass D-1 0.04 parts by mass Cyclohexylbenzene 50 parts by mass Isopropylbiphenyl 50 parts by mass (red light emitting layer composition)
Host-9 0.7 parts by mass D-10 0.04 parts by mass Cyclohexylbenzene 50 parts by mass Isopropyl biphenyl 50 parts by mass Example 9
<< Production of White Organic EL Element 9-1 >>
Transparent support provided with this ITO transparent electrode after patterning on a substrate (NH45 manufactured by NH Techno Glass Co., Ltd.) formed by depositing 100 nm of ITO (indium tin oxide) on a glass substrate of 100 mm × 100 mm × 1.1 mm as an anode The substrate was ultrasonically cleaned with isopropyl alcohol, dried with dry nitrogen gas, and subjected to UV ozone cleaning for 5 minutes.

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

  This substrate was transferred to a nitrogen atmosphere, and a solution of 50 mg of the hole transport material 6 dissolved in 10 ml of toluene was formed on the first hole transport layer by spin coating at 1000 rpm for 30 seconds. After irradiating with ultraviolet light for 180 seconds to carry out photopolymerization / crosslinking, vacuum drying was performed at 60 ° C. for 1 hour to form a second hole transport layer.

  Next, a solution prepared by dissolving Host-25 (60 mg), D-6 (3.0 mg), and D-24 (3.0 mg) in 6 ml of toluene was prepared by spin coating at 1000 rpm for 30 seconds. Filmed. It vacuum-dried at 60 degreeC for 1 hour, and was set as the light emitting layer.

  Further, using a solution obtained by dissolving Compound Example 3 (30 mg) in 5 ml of hexafluoroisopropanol (HFIP), a film was formed by spin coating at 1500 rpm for 30 seconds, followed by vacuum drying at 60 ° C. for 1 hour. It was a blocking layer.

Subsequently, this substrate was fixed to a substrate holder of a vacuum vapor deposition apparatus, and 200 mg of Alq ₃ was put into a molybdenum resistance heating boat and attached to the vacuum vapor deposition apparatus. After reducing the pressure of the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing Alq ₃ was energized and heated, and deposited on the electron transport layer at a deposition rate of 0.1 nm / second to further form a film. An electron transport layer having a thickness of 40 nm was provided.

  In addition, the substrate temperature at the time of vapor deposition was room temperature.

  Subsequently, 0.5 nm of potassium fluoride and 110 nm of aluminum were deposited to form a cathode, and an organic EL element 9-1 was produced.

  When this element was energized, almost white light was obtained, and it was found that it could be used as a lighting device. In addition, it turned out that white light emission is obtained similarly even if it replaces with the other compound of illustration.

It is the schematic diagram which showed an example of the display apparatus comprised from an organic EL element. 4 is a schematic diagram of a display unit A. FIG. It is a schematic diagram of a pixel. It is a schematic diagram of a passive matrix type full color display device. It is the schematic of an illuminating device. It is a schematic diagram of an illuminating device. The schematic block diagram of an organic electroluminescent full color display apparatus is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line 7 Power supply line 10 Organic EL element 11 Switching transistor 12 Drive transistor 13 Capacitor A Display part B Control part 101 Organic EL element 102 Glass cover 105 Cathode 106 Organic EL layer 107 Glass substrate with a transparent electrode 108 Nitrogen gas 109 Water trapping agent 201 Glass substrate 202 ITO transparent electrode 203 Partition wall 204 Hole injection layer 205B, 205G, 205R Light emitting layer

Claims (18)

In an organic electroluminescence device in which a plurality of constituent layers including a light emitting layer are sandwiched between an anode and a cathode,
The constituent layer has an electron transport layer containing at least one compound represented by the following general formula (1) having at least one pyridine ring as a partial structure, and at least one of the light emitting layers is phosphorescent. An element belonging to Group 1 or Group 2 of the periodic table in the constituent layer containing an organometallic complex and in contact with the cathode or the cathode, wherein the metal ion (M ^{n +} ) / metal (M ) System standard electrode potential is -3Vvs. An organic electroluminescence device comprising a metal or a metal compound of an element larger than SHE.

[Wherein, R _{1 to} R ₇ each represents a hydrogen atom or a substituent. A represents a phenyl group, or a substituted or unsubstituted aromatic heterocyclic group having a substituent. However, A contains at least one carbazole ring, azacarbazole ring, dibenzofuran ring or dibenzothiophene ring as a partial structure. ] The organic electroluminescent device according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (2).

[Wherein, R _{11 to} R ₁₇ each represent a hydrogen atom or a substituent, X represents —O—, —S—, or —N (R ₁₀ ) —, and R ₁₀ represents a hydrogen atom or a substituent. Represents. X _{11 to} X ₁₇ represent —C (R ₁₈ ) ═ or —N═, and R ₁₈ represents a hydrogen atom or a substituent. When a plurality of —C (R ₁₈ ) ═ are present, R ₁₈ may be the same or different. However, at least one of R _{10 to} R ₁₈ represents a substituent. ] X in the general formula (2) represents —N (R ₁₀ ) —, R _{11 to} R ₁₄ , R ₁₆ and R ₁₇ each represent a hydrogen atom, and X ₁₁ , X ₁₂ , X _{14 to} X _17. Each represents -CH = or -N =, The organic electroluminescence device according to claim 2, wherein Wherein X in the general formula (2) represents -O- or _-S-, a _{R 11 ~R 14, R 16,} R 17 are each a hydrogen atom, _and, X _{11, X 12,} X 14 _{to X 17} Each represents -CH =, The organic electroluminescent element of Claim 2 characterized by the above-mentioned. The organic electroluminescent device according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (3).

[Wherein, R _{21 to} R ₂₇ each represent a hydrogen atom or a substituent. X _{21 to} X ₂₈ each represent —C (R ₂₈ ) ═ or —N═, and R ₂₈ represents a hydrogen atom or a substituent. When there are a plurality of —C (R ₂₈ ) ═, R ₂₈ may be the same or different. However, at least one of R _{21 to} R ₂₈ represents a substituent. ] In the general formula (3), R _{21 to} R ₂₄ , R ₂₆ and R ₂₇ each represent a hydrogen atom, and X ₂₁ , X ₂₂ , X ₂₄ , X ₂₅ , X ₂₇ and X ₂₈ are each —CH═ or The organic electroluminescence device according to claim 5, wherein -N = is represented. The organic electroluminescent device according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (4).

[Wherein R _{31 to} R ₃₇ each represents a hydrogen atom or a substituent. X _{31 to} X ₃₅ each represent —C (R ₃₈ ) ═ or —N═, and R ₃₈ represents a hydrogen atom or a substituent. Provided _that at least one of X 31 _{to X 35 are,} -C _{where R 38} represents a substituent _{(R 38)} is =. When there are a plurality of —C (R ₃₈ ) ═, R ₃₈ may be the same or different. ] _{R 31 ~R 34, R 36,} R 37 in the general formula (4) each represent a hydrogen _{atom, X 33} is as defined in claim 7, characterized in that represents the -CH = or -N = Organic electroluminescence device. The said element represents sodium, potassium, or cesium, The organic electroluminescent element of any one of Claims 1-8 characterized by the above-mentioned. 10. The organic electroluminescence device according to claim 1, wherein at least one of the phosphorescent organometallic complexes is a compound represented by the following general formula (5).

[Wherein, P and Q each represent a carbon atom or a nitrogen atom, and A1 represents an atomic group which forms an aromatic hydrocarbon ring or an aromatic heterocycle together with PC. A2 represents an atomic group which forms an aromatic heterocycle with QN. P ₁ -L ₁ -P ₂ represents a bidentate ligand, and P ₁ and P ₂ each independently represent a carbon atom, a nitrogen atom, or an oxygen atom. L1 represents an atomic group forming a bidentate ligand together with P ₁ and P ₂ . j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M ₁ represents a group 8-10 metal element in the periodic table. ] The organic electroluminescence device according to claim 10, wherein the compound represented by the general formula (5) is a compound represented by the following general formula (6).

[Wherein Z represents a hydrocarbon ring group or a heterocyclic group. P and Q each represent a carbon atom or a nitrogen atom, and A1 represents an atomic group that forms an aromatic hydrocarbon ring or an aromatic heterocyclic ring together with PC. A3 is _{-C (R 01) = C (} R 02) -, - N = C (R 02) -, - C (R 01) = N- or -N = N-a _{represents, R 01,} R ₀₂ is , Each represents a hydrogen atom or a substituent. P ₁ -L ₁ -P ₂ represents a bidentate ligand, and P ₁ and P ₂ each independently represent a carbon atom, a nitrogen atom, or an oxygen atom. L1 represents an atomic group forming a bidentate ligand together with P ₁ and P ₂ . j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M ₁ represents a group 8-10 transition metal element in the periodic table. ] The organic electroluminescent device according to claim 11, wherein the compound represented by the general formula (6) is a compound represented by the following general formula (7).

[Wherein R ₀₃ represents a substituent, R ₀₄ represents a hydrogen atom or a substituent, and a plurality of R ₀₄ may be bonded to each other to form a ring. n01 represents an integer of 1 to 4. R ₀₅ represents a hydrogen atom or a substituent, and a plurality of R ₀₅ may be bonded to each other to form a ring. n02 represents an integer of 1 to 2. R ₀₆ represents a hydrogen atom or a substituent, and may combine with each other to form a ring. n03 represents an integer of 1 to 4. Z1 represents an atomic group necessary for forming a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocycle together with C—C. Z2 represents an atomic group necessary for forming a hydrocarbon ring or a heterocyclic ring. P ₁ -L ₁ -P ₂ represents a bidentate ligand, and P ₁ and P ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L1 represents an atomic group forming a bidentate ligand together with P ₁ and P ₂ . j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M ₁ represents a group 8-10 transition metal element in the periodic table. R ₀₃ and R ₀₆ , R ₀₄ and R _06, and R ₀₅ and R ₀₆ may be bonded to each other to form a ring. ] The organic electroluminescence device according to claim 12, wherein the compound represented by the general formula (7) is a compound represented by the following general formula (8).

[Wherein R ₀₃ represents a substituent, R ₀₄ represents a hydrogen atom or a substituent, and a plurality of R ₀₄ may be bonded to each other to form a ring. n01 represents an integer of 1 to 4. R ₀₅ represents a hydrogen atom or a substituent, and a plurality of R ₀₅ may be bonded to each other to form a ring. n02 represents an integer of 1 to 2. R ₀₆ represents a hydrogen atom or a substituent, and may combine with each other to form a ring. n03 represents an integer of 1 to 3. R ₀₇ represents a substituent or a single bond. P ₁ -L ₁ -P ₂ represents a bidentate ligand, and P ₁ and P ₂ each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L1 represents an atomic group forming a bidentate ligand together with P ₁ and P ₂ . j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M ₁ represents a group 8-10 transition metal element in the periodic table. ] The organic electroluminescent element according to claim 10, wherein M ₁ represents iridium. The organic electroluminescent element according to claim 1, wherein at least two organic layers including the electron transport layer and the light emitting layer are formed by a wet method. The organic electroluminescence element according to claim 1, which emits white light. An illuminating device comprising the organic electroluminescence element according to claim 1. A display device comprising the organic electroluminescence element according to claim 1.

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