JP2011119576A - Organic electroluminescence element, display device and lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic electroluminescence element that provides singular light emission of short wave, exhibits high light emission efficiency, and has long light emission lifetime and superior solution stability, a display device and a lighting device. <P>SOLUTION: The invention relates to the organic electroluminescence element having a plurality of organic compound layers held between an anode and a cathode, at least one of the organic compound layer containing at least one kind of metal complex compound composed of a nitrogen-containing heterocyclic ring and transition metal; and the display device and lighting device. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  Conventionally, as a light-emitting electronic display device, there is an electroluminescence display (hereinafter referred to as ELD). Examples of the constituent elements of ELD include inorganic electroluminescent elements and organic electroluminescent elements (hereinafter also referred to as organic EL elements).

  Inorganic electroluminescent elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements.

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

  However, for organic EL elements for practical use in the future, development of organic EL elements that emit light with high luminance even at short wave wavelengths with low power consumption is desired.

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

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

  It is disclosed that a metal complex having phenylpyrazole as a ligand is a light emitting material having a short emission wavelength (for example, see Patent Documents 1 and 2). Furthermore, a metal complex formed from a ligand having a partial structure in which a 6-membered ring is condensed to a 5-membered ring of phenylpyrazole is disclosed (for example, see Patent Documents 3 and 4). There is a disclosure about a metal complex having a phenanthridine skeleton (see, for example, Patent Documents 5 and 6).

  As described above, many light emitting materials have been studied focusing on iridium complexes and platinum complexes, but they have high luminous efficiency, low driving voltage, excellent heat resistance, raw storage stability, and long life. From the viewpoint of providing an EL element, it is still insufficient, and further solutions are being sought.

  On the other hand, because of demands for large area, low cost, and high productivity, there is a great expectation for wet methods (also called wet processes, etc.), and film formation can be performed at a lower temperature than film formation by vacuum process. There is great expectation from the viewpoint of improving the light emission efficiency and the device lifetime because the damage of the lower organic layer can be reduced (for example, Patent Documents 7 and 8). In these documents, wet film formation using an ionic metal complex is realized. However, in order to realize wet film formation in an organic EL element using blue phosphorescence, from a practical point of view, currently known luminescent materials have solubility in solvents, solution stability, and driving voltage. It has been found that the device lifetime is still insufficient and further improvement techniques are indispensable.

International Publication No. 2004/085450 Pamphlet JP 2005-53912 A JP 2006-28101 A US Pat. No. 7,147,937 US Patent Publication No. 2007/0190359 International Publication No. 2007/095118 Pamphlet JP 2002-302671 A International Publication No. 2007/006380 Pamphlet

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an organic electroluminescence that exhibits specific short-wave emission, exhibits high emission efficiency, has a long emission lifetime, and has excellent solution stability. It is providing a luminescence element, an illuminating device, and a display apparatus.

  In particular, it is to provide an organic electroluminescence device which exhibits high luminous efficiency with blue to blue-green short-wave light emission, low driving voltage, long light emission lifetime, and excellent solution stability.

  The above object of the present invention can be achieved by the following configuration.

  1. An organic electroluminescent device comprising a plurality of organic compound layers sandwiched between an anode and a cathode, wherein at least one of the organic compound layers is a compound represented by the following general formula (1), or a general formula An organic electroluminescence device comprising at least one compound represented by (2).

( _Wherein E _2a and E _2b each independently represents a carbon atom which may have a substituent, a nitrogen atom, an oxygen atom or a sulfur atom which may have a substituent. E _2c , E _2d and E _2k, and _{E 2o} each independently a carbon atom or, represent a nitrogen atom _.E 2l to E ₂ n is may have independently a substituent carbon atoms or a _{.X 11} that represents a nitrogen atom - L ₁₁ -X ₁₂ represents a bidentate ligand, and X ₁₁ and X ₁₂ each independently represents a carbon atom, a nitrogen atom, or an oxygen atom, and L ₁₁ represents a bidentate coordination with X ₁₁ and X _12. R ₁₁ and R ₁₂ each independently represent a hydrogen atom or a substituent and may be bonded to each other to form a ring, and R ₂₁ represents a substituent. ₂₂ is an oxygen atom or a substituted group _{.R 21} and _{R 22} are bonded to each other May form a ring .m11 1, 2, or,, .m21 represents an integer of 3 is 0, 1 or,, .Y ₁ representing two integer represents a counter anion, n1 is a whole complex molecules Represents an integer of 2 or 3 so as to neutralize the charge, and the bond between M ₁ and X ₁₁ , or M ₁ and X ₁₂ is a covalent bond or a coordination bond, where M ₁ is an element (Represents transition metal elements of groups 8 to 10 in the periodic table.)
2. An organic electroluminescent device comprising a plurality of organic compound layers sandwiched between an anode and a cathode, wherein at least one of the organic compound layers is a compound represented by the following general formula (3), or a general formula An organic electroluminescence device comprising at least one compound represented by (4).

(In formula, E _<1a> , E _<1b> respectively independently represents the carbon atom which may have a substituent, the nitrogen atom which may have a substituent, an oxygen atom, or a sulfur atom. E < _1c >, E _<1d> , E _1e , E _1j , E _1k , and E _1o each independently represent a carbon atom or a nitrogen atom, and E _{1f to} E _1i and E _{1l to} E _1n each independently represent a carbon atom that may have a substituent. Or a nitrogen atom, a skeleton composed of two nitrogen atoms coordinated to E _{1a to} E _1o and M has a total of 18π electrons, and X ₁ -L ₁ -X ₂ is a bidentate coordination. X ₁ and X ₂ each independently represents a carbon atom, a nitrogen atom, or an oxygen atom, and L ₁ represents an atomic group that forms a bidentate ligand together with X ₁ and X _2. Represents an integer of 1, 2, or 3. m2 represents an integer of 0, 1, or 2. Y Represents a counter anion and n represents an integer of 2 or 3 so as to neutralize the charge of the entire complex molecule, and the bond between M and X ₁ , or M and X ₂ is a covalent bond, or (It is a coordinate bond. M represents a group 8-10 transition metal element in the periodic table.)
3. The compound represented by the general formula (3) is represented by the following general formula (5), or the compound represented by the general formula (4) is represented by the following general formula (6). 3. The organic electroluminescence device as described in 2 above, which is a compound.

(In formula, E _{< 1a} > _-E <_1o> is synonymous with E _{< 1a} > _-E <_1o> in the said General formula (3) or General formula (4), respectively. Two nitrogen atoms coordinated to E _{< 1a} > _-E <_1o> and M are each. In total, 18 π electrons are included in the skeleton, and L ₁ represents an atomic group that forms a bidentate ligand together with two nitrogen atoms, and Y and M represent the above general formula (3) or the general formula, respectively. (It is synonymous with Y and M in (4). M1, m2 and n represent the same integers as m1, m2 and n in General Formula (3) or General Formula (4), respectively.)
4). The compound represented by the general formula (5) is represented by the following general formula (7), or the compound represented by the general formula (6) is represented by the following general formula (8). 4. The organic electroluminescence device as described in 3 above, which is a compound.

_(Wherein, E 1a _{to E 1j} are respectively the general formula (3) or the formula in (4) the same meaning as _{E 1a ~E 1j .R 51, R} 52, R 53, R 61, R 62, And R ₆₃ each independently represents a hydrogen atom or a substituent, and L ₁ , Y and M are respectively synonymous with L ₁ , Y and M in Formula (5) or Formula (6). , M2 and n represent the same integers as m1, m2 and n in the general formula (3) or the general formula (4), respectively.
5). The compound represented by the general formula (7) is a compound represented by the following general formula (9), or the compound represented by the general formula (8) is represented by the following general formula (10). 5. The organic electroluminescence device according to 4 above, which is a compound represented by formula (11) or a compound represented by the general formula (11).

(In formula, E < _1a > -E < _1g > is synonymous with E < _1a > -E < _1g > in the said General formula (3) or General formula (4), respectively. R < ₅₁ >, R < ₅₂ >, R < ₅₃ > is respectively said general formula. (7) have the same meanings as _{R 51,} R _{52, R 53 in, R 61,} R _62, and _{R 63} has the same meaning as _{R 61, R 62,} and _{R 63} in the general formula respectively (8) .R ₅₄ , R ₅₅ , R ₅₆ , R ₅₇ , R ₆₄ and R ₆₅ each independently represent a hydrogen atom or a substituent, and L ₁ , Y and M are each the above general formula (5) or general formula (6). And L ₁ , Y and M in M. m1, m2 and n represent the same integers as m1, m2 and n in General Formula (3) or General Formula (4), respectively.
6). 2. The organic electroluminescence device according to 1 above, wherein m11 is 3 and m12 is 0.

7). 7. The organic electroluminescence device according to 1 or 6, wherein M ₁ is iridium.

  8). 6. The organic electroluminescence device according to any one of 2 to 5, wherein m1 is 3 and m2 is 0.

  9. 9. The organic electroluminescent element according to any one of 2 to 5 and 8, wherein M is iridium.

  10. 10. The organic electroluminescence device as described in any one of 1 to 9 above, wherein at least one selected from the compounds represented by the general formulas (1) to (11) is contained in a light emitting layer.

  11. A layer containing at least one selected from the compounds represented by the general formulas (1) to (11) is manufactured through a step of forming and forming a layer by a wet method (wet process). 11. The organic electroluminescence device according to any one of 1 to 10 above.

  12 The organic electroluminescence device according to any one of 1 to 11, which emits white light.

  13. An illumination device comprising the organic electroluminescence element according to any one of 1 to 12 above.

  14 A display device comprising the organic electroluminescence element according to any one of 1 to 12 above.

  INDUSTRIAL APPLICABILITY According to the present invention, an organic electroluminescence element that exhibits specific short-wave light emission, exhibits high light emission efficiency, has a low driving voltage, has a long light emission lifetime, and has excellent solution stability, and an illumination device using the element The display device could be provided.

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

  In the organic electroluminescent element of the present invention, an organic electroluminescent element having a high light emission efficiency and having a long emission lifetime by the configuration defined in any one of 1 to 12 above, and an illumination device using the element And a display device could be provided.

  Hereinafter, details of each component according to the present invention will be sequentially described.

  The present inventors paid attention to the organic EL element material used for the light emitting layer of the organic EL element, and examined various metal complex compounds used as a light emitting dopant.

  An ionic metal complex has an advantage that it can be applied to a wet process organic EL as a phosphorescent light-emitting material, and various ionic metal complexes have been used. However, as a result of investigations by the present inventors, when the molecular structure is controlled to a region where the emission wavelength is shorter than green to red, the stability of the organic EL element is remarkably lowered and the driving voltage tends to be increased. I understood that.

  On the other hand, the present inventors can introduce a substituent into the basic skeleton of the metal complex to expand the π-conjugated surface of the condensed ring, rather than the conventionally known approach of controlling the wavelength and improving the lifetime. Various complexes have been studied under the focus of increasing the stability of compounds. As a result, a tendency to improve the lifetime has been found in some condensed ring structures (for example, imidazophenanthridine, pyrazolophenanthridine, etc.). The organic EL element was successfully developed. However, the development of these metal complexes in a wet process has not been sufficient due to a decrease in solubility. Therefore, in application to a wet process, it has two sites (for example, two nitrogen atoms) that coordinately bond to a metal as in the present invention from a condensed ring structure such as imidazophenanthridine or pyrazolophenanthridine. The ligands were molecularly designed and various ionic metal complexes were synthesized. An ionic metal complex having such a ligand has improved solubility compared to an ortho metal complex having imidazophenanthridine or pyrazolophenanthridine as a ligand, and is suitable for a wet process. It became possible to provide materials. Furthermore, it was found that the stability of the metal complex including high temperature is improved as compared with the conventional ionic metal complex.

(Transition metal element of group 8-10 of the periodic table)
The metal used for forming the compound (also referred to as transition metal complex, metal complex, or metal complex compound) containing the structure represented by any one of the general formulas (1) to (11) according to the present invention is an element period. Although the transition metal element of the 8-10 group of a table | surface (it is only called a transition metal) is used, Iridium and platinum are mentioned as a preferable transition metal element especially.

(Contained layer of transition metal complex according to the present invention)
The transition metal complex compound-containing layer represented by any one of the general formulas (1) to (11) according to the present invention is not particularly limited as long as it is a layer that transports charges (charge transport layer). A hole transport layer or a light emitting layer, a light emitting layer or an electron blocking layer is preferable, a light emitting layer or an electron blocking layer is more preferable, and a light emitting layer is particularly preferable.

  Moreover, when it contains in a light emitting layer, by using as a light emission dopant in a light emitting layer, the efficiency improvement (high brightness) of the external extraction quantum efficiency of the organic EL element of this invention and the lifetime improvement of a light emission lifetime are achieved. be able to. The constituent layers of the organic EL element of the present invention will be described in detail later.

  First, the structure represented by any one of the general formulas (1) to (11) according to the present invention will be described.

<< Structure Represented by either General Formula (1) or (2) >>
The structure represented by either general formula (1) or (2) according to the present invention will be described.

In the structure represented by either general formula (1) or (2), the ring formed by E _{2a to} E _2d and a nitrogen atom represents a 5-membered aromatic heterocycle, such as an oxazole ring or thiazole. Ring, oxadiazole ring, oxatriazole ring, isoxazole ring, tetrazole ring, thiadiazole ring, thiatriazole ring, isothiazole ring, thiophene ring, furan ring, pyrrole ring, imidazole ring, pyrazole ring, triazole ring, etc. .

  Among these, a pyrazole ring, an imidazole ring, an oxazole ring, and a thiazole ring are preferable, and a pyrazole ring and an imidazole ring are particularly preferable.

In the structure represented by either general formula (1) or (2), the ring formed by E _{2k to} E _2o and a nitrogen atom represents a 6-membered aromatic heterocycle.

_Examples of the 6-membered aromatic heterocycle formed by E _{2k to} E _2o include a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, and a triazine ring. May further have a substituent represented by _{R 63} from _{R 53,} and _{R 61} from formula _{R 51} represented by the below general formula (7) - (8).

In the structure represented by either general formula (1) or (2), when R ₁₁ , R ₁₂ , R ₂₁ , R ₂₂ represent a substituent, specific examples thereof are represented by general formulas (7) to (7) described later. it is the general formula of _{R 51} of the formula (8) from _{R 53,} and _{R 61} include a substituent represented by _{R 63.}

In the structure represented by either the general formula (1) or (2), specific examples of the bidentate ligand represented by X ₁₁ -L ₁₁ -X ₁₂ include substituted or unsubstituted phenylpyridine, Examples include phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabole, acetylacetone, and picolinic acid.

  m11 represents an integer of 1, 2 or 3, m12 represents an integer of 0, 1 or 2, and m11 + m12 is 2 or 3. Especially, the case where m12 is 0 is preferable.

M ₁ represents a transition metal element of Group 8 to Group 10 in the periodic table, and is preferably iridium or platinum.

Y ₁ represents a counter anion, and n 1 represents an integer of 2 or 3. Specific examples of counter anions include halogen ions (chlorine ions, bromine ions, iodine ions), perchlorate ions, PF ₆ ⁻ , borate ions (tetraphenyl borate ions, BF ₄ ^−, etc.), sulfonate ions (polystyrene sulfone). Acid ion, methanesulfonate ion, trifluoromethanesulfonate ion, etc.), carboxylate ion, CN- ^{and the} like.

  The organic compound layer containing the compound (ionic transition metal complex) represented by either general formula (1) or (2) is only the compound represented by either general formula (1) or (2). Or a layer in which the compound is dispersed in a polymer binder such as polyethylene oxide, polyethylene sulfonic acid, polycarbonate, or polyester. This layer may contain a plurality of types of ionic transition metal complexes, and may function as a light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, and / or an electron injection layer.

<< Structure represented by General Formula (3) or (4) >>
The structure represented by either general formula (3) or (4) according to the present invention will be described.

In the structure represented by either general formula (1) or (2), the ring formed by E _{1a to} E _1d and a nitrogen atom represents a 5-membered aromatic heterocycle, such as an oxazole ring or thiazole. Ring, oxadiazole ring, oxatriazole ring, isoxazole ring, tetrazole ring, thiadiazole ring, thiatriazole ring, isothiazole ring, thiophene ring, furan ring, pyrrole ring, imidazole ring, pyrazole ring, triazole ring, etc. .

  Among these, a pyrazole ring, an imidazole ring, an oxazole ring, and a thiazole ring are preferable, and a pyrazole ring and an imidazole ring are particularly preferable.

In the structure represented by either general formula (3) or (4), the ring formed by E _{1k to} E _1o and a nitrogen atom represents a 6-membered aromatic heterocycle.

_Examples of the 6-membered aromatic heterocycle formed by E _{1k to} E _1o include a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, and a triazine ring. May further have a substituent represented by _{R 63} from _{R 53,} and _{R 61} from formula _{R 51} represented by the below general formula (7) - (8).

In the structure represented by either general formula (3) or (4), the ring formed by E _{1e to} E _1j is a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocyclic ring. Represents.

Examples of the 6-membered aromatic hydrocarbon ring formed by E _{1e to} E _1j include a benzene ring. Furthermore, you may have the substituent mentioned later.

Examples of the 5-membered or 6-membered aromatic heterocycle formed by E _{1e to} E _1j include a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, and a triazine ring. Etc. Note that a skeleton composed of two nitrogen atoms coordinated to E _{1a to} E _1o and M has a total of 18π electrons.

  m1 represents an integer of 1, 2 or 3, m2 represents an integer of 0, 1 or 2, and m1 + m2 is 2 or 3. Especially, the case where m2 is 0 is preferable.

  M represents a transition metal element belonging to Groups 8 to 10 in the periodic table, and is preferably iridium or platinum.

Y represents a counter anion, and n represents an integer of 2 or 3. Specific examples of counter anions include halogen ions (chlorine ions, bromine ions, iodine ions), perchlorate ions, PF ₆ ⁻ , borate ions (tetraphenyl borate ions, BF ₄ ^−, etc.), sulfonate ions (polystyrene sulfone). Acid ion, methanesulfonate ion, trifluoromethanesulfonate ion, etc.), carboxylate ion, CN- ^{and the} like.

  The organic compound layer containing the compound (ionic transition metal complex) represented by either general formula (3) or (4) is only the compound represented by either general formula (3) or (4). Or a layer in which the compound is dispersed in a polymer binder such as polyethylene oxide, polyethylene sulfonic acid, polycarbonate, or polyester. This layer may contain a plurality of types of ionic transition metal complexes, and may function as a light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, and / or an electron injection layer.

<< Structure represented by General Formula (5) or (6) >>
The structure represented by either general formula (5) or (6) according to the present invention will be described.

In the structure represented by any one of formulas (5) or _(6), E 1a _{to E 1o} has the same meaning as _E 1a _{to E 1o} in each Formula (3) or (4). L ₁ represents an atomic group that forms a bidentate ligand with two nitrogen atoms. Y and M are synonymous with Y and M in the general formula (3) or (4), respectively. m1, m2, and n represent the same integer as m1, m2, and n in the general formula (3) or (4), respectively. Note that a skeleton composed of two nitrogen atoms coordinated to E _{1a to} E _1o and M has a total of 18π electrons.

  In the present invention, among the structures represented by the general formula (5) or (6), the structure represented by the general formula (5) is preferable.

  In the present invention, among the structures represented by either the general formula (3) or (4), the structure represented by any of the above general formulas (5) or (6) is preferable.

<< Structure represented by General Formula (7) or (8) >>
The structure represented by either general formula (7) or (8) according to the present invention will be described.

In the structure represented by any one of formulas (7) or _(8), E 1a _{to E 1j} have the same meanings as _E 1a _{to E 1j} in each Formula (3) or general formula (4). L _1, Y and M have the same meanings as _L 1, Y and M in each of the general formula (5) or the general formula (6). m1, m2, and n represent the same integer as m1, m2, and n in the general formula (3) or (4), respectively.

In the structure represented by either general formula (7) or (8), the substituents represented by R ₅₁ , R ₅₂ , R ₅₃ , R ₆₁ , R ₆₂ , and R ₆₃ are each an alkyl group ( 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 (for example, cyclopentyl group) Cyclohexyl group etc.), alkenyl group (eg vinyl group, allyl group etc.), alkynyl group (eg ethynyl group, propargyl group etc.), 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 Acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl 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, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (carboline ring of the above carbolinyl group) One of the carbon atoms that make up Quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (for example, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (For example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (for example, 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, cyclohexane) Acetylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.), alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxy group) Carbonyl group etc.), aryloxycarbonyl group (eg phenyloxycarbonyl group, naphthyloxycarbonyl group etc.), sulfamoyl group (eg aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylamino) Sulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group, naphthylaminosulfonyl group 2-pyridylaminosulfonyl group etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, Naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (eg, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (eg, Methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonylamino group, cyclohexylcarbonylamino group, Mino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group) Propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl 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, dodecyl group) Raid group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenyl) Sulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (eg, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), aryl Sulfonyl group or heteroarylsulfonyl group (eg, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (example For example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group), halogen atom (for example, Fluorine atom, chlorine atom, bromine atom, etc.), fluorinated hydrocarbon group (eg, 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. These substituents may be further substituted with the above substituents.

  A plurality of these substituents may be bonded to each other to form a ring, and when a plurality of substituents are present, each substituent may be the same or different, and linked to each other to form a ring. May be formed.

  Among them, the substituent is preferably an alkyl group, an aromatic hydrocarbon ring group, or an aromatic heterocyclic group.

  In the present invention, among the structures represented by the general formula (5) or (6), the structure represented by the general formula (7) or (8) is preferable.

<< Structure Represented by any of General Formulas (9) to (11) >>
The structure represented by any one of the general formulas (9) to (11) according to the present invention will be described.

In the structure represented by any one of formulas _{(9) ~ (11),} E 1a ~E 1g has the same meaning as _E 1a _{to E 1 g} of each of the general formula (3) or (4). R ₅₁ , R ₅₂ and R ₅₃ are respectively synonymous with R ₅₁ , R ₅₂ and R ₅₃ in the general formula (7), and R ₆₁ , R ₆₂ and R ₆₃ are respectively R in the general formula (8). _{61, R 62,} and the same meaning as _{R 63.} R ₅₄ , R ₅₅ , R ₅₆ , R ₅₇ , R ₆₄ and R ₆₅ each independently represent a hydrogen atom or a substituent. L _1, Y and M have the same meanings as _L 1, Y and M in each of the general formula (5) or the general formula (6). In the structure represented by any one of the general formulas (9) to (11), each of m1, m2 and n represents the same integer as m1, m2 and n in the general formula (3) or (4), R ₅₄ , R ₅₅ , R ₅₆ , R ₅₇ , R ₆₄ and R ₆₅ may be the substituents described above for R ₅₁ to R ₅₃ and R ₆₁ to R ₆₃ .

  In the present invention, among the structures represented by the general formulas (7) or (8), the structure represented by any one of the general formulas (9) to (11) is preferable. The structure represented by (9) is most preferable.

In the general formulas (1) to (11) of the present invention, it is preferable that two of E _1a to E _1d are nitrogen atoms and two are carbon atoms that may have a substituent. In one preferred embodiment, E _1a and E _1c are nitrogen atoms, and E _1b and E _1d are carbon atoms that may have two substituents. One preferred embodiment is that E _1a and E _1d are nitrogen atoms, and E _1b and E _1c are carbon atoms that may have two substituents.

In one preferred embodiment, E _1b and E _1d are nitrogen atoms, and E _1a and E _1c are carbon atoms that may have two substituents. In one preferred embodiment, E _1c and E _1d are nitrogen atoms, and E _1a and E _1b are carbon atoms that may have two substituents. Most preferably, E _1a and E _1b are nitrogen atoms, and E _1c and E _1d are two carbon atoms that may have a substituent, or E _1b and E _1c are nitrogen atoms, and , E _1a and E _1d are carbon atoms, two of which may have a substituent.

In the general formulas (1) to (11) of the present invention, in the general formula (7) or the general formula (8), one of E _1a to E _1d may have a substituent. More preferably it is an atom.

In one preferred embodiment, E _1a is a nitrogen atom which may have a substituent, and E _1b , E _1c and E _1d are carbon atoms which may have a substituent. In one preferred embodiment, E _1b is a nitrogen atom which may have a substituent, and E _1a , E _1c and E _1d are carbon atoms which may have a substituent. In one preferred embodiment, E _1d is a nitrogen atom which may have a substituent, and E _1a , E _1b and E _1c are carbon atoms which may have a substituent. Most preferably, E _1c is a nitrogen atom which may have a substituent, and E _1a , E _1b and E _1d are carbon atoms which may have a substituent.

In the above general formulas (1) to (11) of the present invention, E _1a , E _1b , E _{1l to} E _1n , E _{1f to} E _1i have a carbon atom which may have a substituent or a substituent. In the structure represented by any one of the general formulas (7) and (8), R ₅₁ , R ₅₂ , R ₅₃ , R ₆₁ , R ₆₂ , And R ₆₃ has the same meaning as the substituent represented by each. Preferred examples of the substituent include an alkyl group, an aromatic hydrocarbon ring group, and an aromatic heterocyclic group.

  Hereinafter, specific examples of the compound of the present invention represented by any one of the general formulas (1) to (11) according to the present invention (also referred to as a metal complex or a metal complex compound) will be shown. It is not limited. In the specific example here, the counter anion is not shown, so the charge of the entire complex molecule is positive. In each of the following compounds, the counter anion exemplified in the description of Y can be appropriately used so that the charge of the entire complex molecule is neutralized.

Examples of ionic metal complexes such as the compounds of the present invention are described in Pure Appl. Chem. , 52, 2717, (1980). Etc., and can be synthesized by various known methods. For example, a ligand (compound A or the like), or a dissociated product thereof and a transition metal compound (eg, K ₃ IrCl ₆ , iridium trisacetylacetonate complex) are used as a solvent (eg, a halogen-based solvent, an alcohol-based solvent, an ether-based solvent, In the presence of water) or in the absence of a solvent, in the presence of a base (a variety of inorganic and organic bases such as sodium methoxide, t-butoxypotassium, triethylamine, potassium carbonate, etc.) Alternatively, it can be obtained in the absence of a base, at room temperature or below, or by heating (in addition to normal heating, a method of heating with a microwave is also effective).

  Below, the synthesis example of the compound (1) of this invention is shown.

Synthesis of Compound (1) 0.5 g of K ₃ IrCl ₆ and 0.75 g of Compound Z were heated in a mixed solvent of 20 ml of 2-methoxyethanol and 5 ml of water for 8 hours, and the precipitated crystals were separated by filtration. 0.3 g of compound (1) was obtained.

<< 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 / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron Transport layer / cathode (iv) Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) Anode / anode buffer layer / hole transport layer / light emitting layer / hole Blocking layer / electron transport layer / cathode buffer layer / cathode In the organic EL device of the present invention, the blue light emitting layer preferably has a light emission maximum wavelength of 430 nm to 480 nm, and the green light emitting layer has a light emission maximum wavelength of 510 nm to 550 nm, The red light emitting layer is preferably a monochromatic light emitting layer having a light emission maximum wavelength in the range of 600 nm to 640 nm, and is preferably a display device using these. Alternatively, a white light emitting layer may be formed by laminating at least three light emitting layers. Further, a non-light emitting intermediate layer may be provided between the light emitting layers. The organic EL element of the present invention is preferably a white light emitting layer, and is preferably a lighting device using these.

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

<Light emitting layer>
The light emitting layer according to the present invention is a layer that emits light by recombination of electrons and holes injected from the electrode, the electron transport layer, or the hole transport layer, and the light emitting portion is in the layer of the light emitting layer. May 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 10 nm to 20 nm.

  For the production of the light-emitting layer, a light-emitting dopant or a host compound, which will be described later, is formed by a known thinning method such as a vacuum deposition method, a spin coating method, a casting method, an LB method, or an ink-jet method. it can.

  The light emitting layer of the organic EL device of the present invention preferably contains a light emitting host compound and at least one kind of light emitting dopant (such as a phosphorescent dopant (also referred to as a phosphorescent dopant) or a fluorescent dopant).

(Host compound (also called luminescent host))
The host compound used in the present invention will be described.

  Here, the host compound in the present invention is a phosphorescent quantum yield of phosphorescence emission at a room temperature (25 ° C.) having a mass ratio of 20% or more in the compound contained in the light emitting layer. Is defined as a compound of less than 0.1. 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.

  As the host compound, known host compounds may be used alone or in combination of two or more. By using a plurality of types of host compounds, it is possible to adjust the movement of charges, and the organic EL element can be made highly efficient. Moreover, it becomes possible to mix different light emission by using multiple types of light emission dopants mentioned later, and, thereby, arbitrary luminescent colors can be obtained.

  The light emitting host used in the present invention may be a conventionally known low molecular compound or a high molecular compound having a repeating unit, and a low molecular compound having a polymerizable group such as a vinyl group or an epoxy group (deposition polymerization property). Light emitting host).

  Although the specific example of the host compound preferably used for this invention below is shown, this invention is not limited to these.

  As a known host compound that may be used in combination, a compound that has a hole transporting ability and an electron transporting ability, prevents the emission of light from being increased in wavelength, and has a high Tg (glass transition temperature) is preferable.

  Specific examples of known host compounds 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.

(Luminescent dopant)
The light emitting dopant according to the present invention will be described.

  As the light-emitting dopant according to the present invention, 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. From the viewpoint of obtaining an organic EL device with high luminous efficiency, the light emitting dopant used in the light emitting layer or the light emitting unit of the organic EL device of the present invention (sometimes simply referred to as a light emitting material) contains the above host compound. At the same time, it is preferable to contain a phosphorescent dopant.

(Phosphorescent dopant)
The phosphorescent dopant will be described.

  The phosphorescent dopant according to the present invention, which may be used in combination with the present invention, is a phosphorescent dopant, preferably a complex compound containing a group 8-10 metal in the periodic table of elements, more preferably an iridium compound or osmium. Compounds, platinum compounds (platinum complex compounds), and rare earth complexes, and most preferred are iridium compounds.

  The compound used as the phosphorescent dopant according to the present invention includes a transition metal complex including a structure represented by any of the structures represented by any one of the general formulas (1) to (9) according to the present invention. Compounds are preferred.

  Moreover, you may use together a conventionally well-known light emission dopant as shown below.

(Fluorescent dopant (also called fluorescent compound))
In the present invention, conventionally known fluorescent dopants as shown below may be used in combination. Fluorescent dopants (fluorescent compounds) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes Examples thereof include dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

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

<< Injection layer: electron injection layer, hole injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, 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) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

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

  The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer 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.

<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 and 11-204359, and “Organic EL elements and their forefront of industrialization” (issued on November 30, 1998 by NTS Corporation). 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 contains the carbazole derivative, carboline derivative, or diazacarbazole derivative (shown in which any one of the carbon atoms constituting the carboline ring of the carboline derivative is replaced by a nitrogen atom). It is preferable to contain.

  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 an electron at the HOMO (highest occupied molecular orbital) level of the compound to the vacuum level, and can be obtained by the following method, for example.

  (1) Using Gaussian 03 (Gaussian 03, Revision D.02, MJ Frisch, et al, Gaussian, Inc., Pittsburgh PA, 2004.), a molecular orbital calculation software manufactured by Gaussian, USA, as a keyword. The ionization potential can be obtained as a value obtained by rounding off the second decimal place of the value (eV unit converted value) calculated by performing structural optimization using / 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 thicknesses of the hole blocking layer and the electron transport layer according to the present invention are 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, as well as 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, 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.

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

  Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. As long as it has a function of transferring electrons to the light-emitting layer, any material can be selected and used from among conventionally known compounds. For example, nitro-substituted fluorene derivatives, diphenylquinone derivatives Thiopyrandioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives and the like.

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

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

  In addition, metal-free or metal phthalocyanine, or those having terminal ends substituted with an alkyl group or a sulfonic acid group can be preferably used as the electron transporting material. In addition, the distyrylpyrazine derivative exemplified as the material of the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and the hole transport layer. Can also be used as an electron transporting material.

  The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method. Although there is no restriction | limiting in particular about the film thickness of an electron carrying layer, Usually, 5 nm-about 5 micrometers, Preferably it is 5 nm-200 nm. The electron transport layer may have a single layer structure composed of one or more of the above materials.

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

  In the present invention, it is preferable to use an electron transport layer having such a high n property because an element with lower power consumption can be manufactured.

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound and 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 required (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.

"cathode"
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like. Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred.

  The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as a cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm. In order to transmit the emitted light, if either one of the anode or the cathode of the organic EL element is transparent or translucent, the light emission luminance is improved, which is convenient.

  Moreover, after producing the said metal by the film thickness of 1 nm-20 nm to a cathode, the transparent or semi-transparent cathode can be produced by producing the electroconductive transparent material quoted by description of the anode on it, By applying this, an element in which both the anode and the cathode are transmissive can be manufactured.

《Support substrate》
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.

<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. Therefore, 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 of improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate and preventing total reflection at the transparent substrate and the air interface (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.

《Condensing 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 with a triangle stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

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

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

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

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

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

  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 these layers are formed, a thin film made of a cathode material is formed thereon by 1 μm or less, preferably by a method such as vapor deposition or sputtering so that the film thickness is in the range of 50 nm to 200 nm. By providing, a desired organic EL element can be obtained.

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

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

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

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

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

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these. Moreover, the structure of the compound used in 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, 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. After the film formation by spin coating, the film was 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 compound A 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 obtained by dissolving H-1 (60 mg) and Comparative 1 (3.0 mg) in 6 ml of acetonitrile was formed by spin coating under conditions of 1000 rpm and 30 seconds to provide a light emitting layer.

Subsequently, this substrate was fixed to a substrate holder of a vacuum deposition apparatus, 200 mg of BAlq was put into a molybdenum resistance heating boat, and attached to the vacuum deposition apparatus. After reducing the pressure of the vacuum chamber to 4 × 10 ⁻⁴ Pa, the heating boat containing BAlq is heated by heating, evaporated onto the light emitting layer at a deposition rate of 0.1 nm / second, and further an electron having a thickness of 40 nm. A transport layer was provided.

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

  Then, 0.5 nm of lithium fluoride and 110 nm of aluminum were vapor-deposited, the cathode was formed, and the white light emitting organic EL element was produced.

<< Production of Organic EL Elements 1-2 to 1-40 >>
In the production of the organic EL element 1-1, organic EL elements 1-2 to 1-40 were produced in the same manner except that the combination of the dopant compound and the host compound in the light emitting layer was changed to the combination shown in Table 1.

<< Evaluation of organic EL elements >>
When evaluating the obtained organic EL elements 1-1 to 1-40, the non-light-emitting surface of each organic EL element after production was covered with a glass case, and a glass substrate having a thickness of 300 μm was used as a sealing substrate. An epoxy photo-curing adhesive (Lux Track LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealant around the periphery, and this is placed on the cathode so as to be in close contact with the transparent support substrate and irradiated with UV light from the glass substrate side. Then, it was cured and sealed, and an illumination device as shown in FIGS. 3 and 4 was formed and evaluated.

  FIG. 3 is a schematic diagram of the lighting device, and the organic EL element 101 is covered with a glass cover 102 (in addition, the sealing operation with the glass cover is performed in a nitrogen atmosphere without bringing the organic EL element 101 into contact with the atmosphere. (In a high purity nitrogen gas atmosphere with a purity of 99.999% or more).

  FIG. 4 is a cross-sectional view of the lighting device, 105 is a cathode, 106 is an organic EL layer, and 107 is 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.

(External quantum efficiency)
By lighting the organic EL element under a constant current condition of room temperature (about 23 to 25 ° C.) and ^2.5 mA / cm ² , and measuring the light emission luminance (L) [cd / m ² ] immediately after the start of lighting, 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 1-1 as 100.

(Half life)
The half-life was evaluated according to the measurement method shown below.

Each organic EL device driven with a constant current at a current giving an initial luminance 1000 cd / ^{m 2,} obtains the time to be 1/2 (500cd / ^{m 2)} of the initial luminance, which was used as a measure of the half-life.

  The half-life was expressed as a relative value when the comparative organic EL element 1-1 was set to 100.

(Drive voltage)
The drive voltage is a voltage when driven at ^2.5 mA / cm ² , and the difference from the drive voltage (V) of the comparative organic EL element 1-1 was obtained.

Drive voltage (V) = Drive voltage (V) of the organic EL element 1-1−Drive voltage (V) of the organic EL element of the present invention
(Stillness stability of the light emitting layer coating solution (solution stability))
In the production of the organic EL device 1-1, the coating solution used for forming the light emitting layer (a solution obtained by dissolving a mixture of H-1 (60 mg) and Comparative 1 (3.0 mg) in 12 ml of butanol) at room temperature for 1 hour. After standing, the presence or absence of precipitation was confirmed.
○: There is no visual observation Δ: There is faint precipitation by visual observation ×: There is a clear visual observation

  From Table 1, it is clear that the organic EL device of the present invention has a high external extraction quantum efficiency and a low driving voltage as compared with the comparative device. It was also found that the stagnation stability of the light emitting layer coating solution was also improved.

Example 2
<Production of full-color display device>
(Production of blue light emitting element)
The organic EL element 1-8 of Example 1 was used as a blue light emitting element.

(Production of green light emitting element)
In the organic EL element 1-1 of Example 1, a green light emitting element was produced in the same manner except that the comparison 1 was changed to Ir-1, and this was used as the green light emitting element.

(Production of red light emitting element)
In the organic EL device 1-1 of Example 1, a red light emitting device was produced in the same manner except that the comparison 1 was changed to Ir-9, and this was used as a red light emitting device.

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

  That is, a plurality of pixels 3 (light emission color is a red region pixel, a green region pixel, a blue region pixel, etc.) juxtaposed with a wiring portion including a plurality of scanning lines 5 and data lines 6 on the same substrate. The scanning lines 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a lattice shape and are connected to the pixels 3 at the orthogonal positions (for details, see FIG. Not shown).

  The plurality of pixels 3 are driven by an active matrix system provided with an organic EL element corresponding to each emission color, a switching transistor as an active element, and a driving transistor, and a scanning signal is applied from a scanning line 5. The image data signal is received from the data line 6 and light is emitted according to the received image data. In this way, a full color display device was produced by appropriately juxtaposing red, green, and blue pixels.

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

Example 3
<< Production of White Light Emitting Element and White Lighting Device-2 >>
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, 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. After the film formation by spin coating, the film was 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 compound A 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 obtained by dissolving Compound B (60 mg), Ir-14 (3.0 mg), and Compound 55 (3.0 mg) of the present invention in 6 ml of acetonitrile was spin-coated at 1000 rpm for 30 seconds. A film was formed. Irradiated with ultraviolet light for 15 seconds to cause photopolymerization / crosslinking, and further heated in vacuum at 150 ° C. for 1 hour to obtain a light emitting layer.

  Furthermore, using a solution obtained by dissolving Compound C (20 mg) in 6 ml of butanol, a film was formed by spin coating under conditions of 1000 rpm and 30 seconds. Ultraviolet light was irradiated for 15 seconds, photopolymerization / crosslinking was performed, and further heating was performed in vacuum at 80 ° C. for 1 hour to form a hole 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 depressurizing the vacuum chamber to 4 × 10 ⁻⁴ Pa, energizing and heating the heating boat containing Alq ₃ , depositing on the hole blocking layer at a deposition rate of 0.1 nm / second, 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.

  Then, 0.5 nm of lithium fluoride and 110 nm of aluminum were vapor-deposited, the cathode was formed, and the white light emitting organic EL element 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.

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

Claims (14)

An organic electroluminescent device comprising a plurality of organic compound layers sandwiched between an anode and a cathode, wherein at least one of the organic compound layers is a compound represented by the following general formula (1), or a general formula An organic electroluminescence device comprising at least one compound represented by (2).

( _Wherein E _2a and E _2b each independently represents a carbon atom which may have a substituent, a nitrogen atom, an oxygen atom or a sulfur atom which may have a substituent. E _2c , E _2d and E _2k, and _{E 2o} each independently a carbon atom or, represent a nitrogen atom _.E 2l to E ₂ n is may have independently a substituent carbon atoms or a _{.X 11} that represents a nitrogen atom - L ₁₁ -X ₁₂ represents a bidentate ligand, and X ₁₁ and X ₁₂ each independently represents a carbon atom, a nitrogen atom, or an oxygen atom, and L ₁₁ represents a bidentate coordination with X ₁₁ and X _12. R ₁₁ and R ₁₂ each independently represent a hydrogen atom or a substituent and may be bonded to each other to form a ring, and R ₂₁ represents a substituent. ₂₂ is an oxygen atom or a substituted group _{.R 21} and _{R 22} are bonded to each other May form a ring .m11 1, 2, or,, .m21 represents an integer of 3 is 0, 1 or,, .Y ₁ representing two integer represents a counter anion, n1 is a whole complex molecules Represents an integer of 2 or 3 so as to neutralize the charge, and the bond between M ₁ and X ₁₁ , or M ₁ and X ₁₂ is a covalent bond or a coordination bond, where M ₁ is an element (Represents transition metal elements of groups 8 to 10 in the periodic table.) An organic electroluminescent device comprising a plurality of organic compound layers sandwiched between an anode and a cathode, wherein at least one of the organic compound layers is a compound represented by the following general formula (3), or a general formula An organic electroluminescence device comprising at least one compound represented by (4).

(In formula, E _<1a> , E _<1b> respectively independently represents the carbon atom which may have a substituent, the nitrogen atom which may have a substituent, an oxygen atom, or a sulfur atom. E < _1c >, E _<1d> , E _1e , E _1j , E _1k , and E _1o each independently represent a carbon atom or a nitrogen atom, and E _{1f to} E _1i and E _{1l to} E _1n each independently represent a carbon atom that may have a substituent. Or a nitrogen atom, a skeleton composed of two nitrogen atoms coordinated to E _{1a to} E _1o and M has a total of 18π electrons, and X ₁ -L ₁ -X ₂ is a bidentate coordination. X ₁ and X ₂ each independently represents a carbon atom, a nitrogen atom, or an oxygen atom, and L ₁ represents an atomic group that forms a bidentate ligand together with X ₁ and X _2. Represents an integer of 1, 2, or 3. m2 represents an integer of 0, 1, or 2. Y Represents a counter anion and n represents an integer of 2 or 3 so as to neutralize the charge of the entire complex molecule, and the bond between M and X ₁ , or M and X ₂ is a covalent bond, or (It is a coordinate bond. M represents a group 8-10 transition metal element in the periodic table.) The compound represented by the general formula (3) is represented by the following general formula (5), or the compound represented by the general formula (4) is represented by the following general formula (6). 3. The organic electroluminescence device according to claim 2, wherein the organic electroluminescence device is a compound.

(In formula, E _{< 1a} > _-E <_1o> is synonymous with E _{< 1a} > _-E <_1o> in the said General formula (3) or General formula (4), respectively. Two nitrogen atoms coordinated to E _{< 1a} > _-E <_1o> and M are each. In total, 18 π electrons are included in the skeleton, and L ₁ represents an atomic group that forms a bidentate ligand together with two nitrogen atoms, and Y and M represent the above general formula (3) or the general formula, respectively. (It is synonymous with Y and M in (4). M1, m2 and n represent the same integers as m1, m2 and n in General Formula (3) or General Formula (4), respectively.) The compound represented by the general formula (5) is represented by the following general formula (7), or the compound represented by the general formula (6) is represented by the following general formula (8). The organic electroluminescence device according to claim 3, which is a compound.

_(Wherein, E 1a _{to E 1j} are respectively the general formula (3) or the formula in (4) the same meaning as _{E 1a ~E 1j .R 51, R} 52, R 53, R 61, R 62, And R ₆₃ each independently represents a hydrogen atom or a substituent, and L ₁ , Y and M are respectively synonymous with L ₁ , Y and M in Formula (5) or Formula (6). , M2 and n represent the same integers as m1, m2 and n in the general formula (3) or the general formula (4), respectively. The compound represented by the general formula (7) is a compound represented by the following general formula (9), or the compound represented by the general formula (8) is represented by the following general formula (10). The organic electroluminescence device according to claim 4, wherein the organic electroluminescence device is a compound represented by formula (11):

(In formula, E < _1a > -E < _1g > is synonymous with E < _1a > -E < _1g > in the said General formula (3) or General formula (4), respectively. R < ₅₁ >, R < ₅₂ >, R < ₅₃ > is respectively said general formula. (7) have the same meanings as _{R 51,} R _{52, R 53 in, R 61,} R _62, and _{R 63} has the same meaning as _{R 61, R 62,} and _{R 63} in the general formula respectively (8) .R ₅₄ , R ₅₅ , R ₅₆ , R ₅₇ , R ₆₄ and R ₆₅ each independently represent a hydrogen atom or a substituent, and L ₁ , Y and M are each the above general formula (5) or general formula (6). And L ₁ , Y and M in M. m1, m2 and n represent the same integers as m1, m2 and n in General Formula (3) or General Formula (4), respectively.   The organic electroluminescence device according to claim 1, wherein m11 is 3 and m12 is 0. The organic electroluminescence device according to claim _1, wherein the M ₁ is iridium.   The organic electroluminescence element according to claim 2, wherein m1 is 3 and m2 is 0.   The organic electroluminescence device according to any one of claims 2 to 5, wherein M is iridium.   The organic electroluminescent element according to claim 1, wherein at least one selected from the compounds represented by the general formulas (1) to (11) is contained in a light emitting layer. .   A layer containing at least one selected from the compounds represented by the general formulas (1) to (11) is manufactured through a step of forming and forming a layer by a wet method (wet process). The organic electroluminescent element of any one of Claims 1-10.   The organic electroluminescent 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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