WO2010095564A1

WO2010095564A1 - Organic electroluminescent element, and illuminating device and display device each comprising the element

Info

Publication number: WO2010095564A1
Application number: PCT/JP2010/052043
Authority: WO
Inventors: 片倉　利恵; 秀雄 ▲高▼; 加藤　栄作
Original assignee: コニカミノルタホールディングス株式会社
Priority date: 2009-02-18
Filing date: 2010-02-12
Publication date: 2010-08-26
Also published as: JPWO2010095564A1; JP5765223B2

Abstract

Disclosed is an organic electroluminescent element which has high external quantum efficiency, low driving voltage and long life. Also disclosed are an illuminating device and a display device, each comprising the element. In the organic electroluminescent element, and the illuminating device and the display device each comprising the element, a plurality of constituent layers including two or more light-emitting layers are interposed between a positive electrode and a negative electrode, and at least two light-emitting layers are produced by a procedure including a wet process.

Description

ORGANIC ELECTROLUMINESCENCE ELEMENT, LIGHTING DEVICE AND DISPLAY DEVICE PROVIDED WITH THE ELEMENT

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

Conventionally, as a light-emitting electronic display device, there is an electroluminescence display (ELD). As a component of ELD, an inorganic electroluminescent element and an organic electroluminescent element are mentioned. Oriented electroluminescent elements have been used as planar light sources, but an alternating high voltage is required to drive the light emitting elements.

On the other hand, an organic electroluminescence element (organic EL element) has a structure in which a thin film containing a fluorescent or phosphorescent organic compound is sandwiched between a cathode and an anode, and recombines by injecting electrons and holes into the thin film. Is an element that emits light by utilizing the emission of light (fluorescence / phosphorescence) when the exciton is deactivated by generating excitons, and at a low voltage of several to several tens of volts. Since it is capable of emitting light and is self-luminous, it has a wide viewing angle dependency, high visibility, and because it is a thin-film, completely solid element, it has attracted attention from the viewpoint of space saving, etc. Deployment has begun.

Developed organic EL elements for practical use A. Baldo et al. Since 1993, Nature, 395, 151-154 (1998), Princeton University has reported an organic EL device using phosphorescence emission from an excited triplet. A. Baldo et al. , Nature, 403, 17, 750-753 (2000), and US Pat. No. 6,097,147, research on materials that exhibit phosphorescence at room temperature has become active.

In addition, recently discovered organic EL devices that use phosphorescence can realize a luminous efficiency that is approximately four times that of previous devices that use fluorescence. Research and development of light-emitting element layer configurations and electrodes are performed all over the world. For example, S.M. Lamansky et al. , J .; Am. Chem. Soc. , 123, 4304 (2001), a number of compounds have been studied for synthesis centering on heavy metal complexes such as iridium complexes.

Usually, organic EL elements are formed by an organic vapor deposition method using a high vacuum such as 10 ⁻⁴ Pa or less (dry process). However, organic EL elements can be increased in size and mass-produced in the future. Considering the properties, the formation of the organic layer by the vacuum deposition method is not preferable in terms of production efficiency and manufacturing cost.

Further, when the dopant is contained in the light emitting layer by the vacuum vapor deposition method, the dopant is uneven on the substrate during the vapor deposition, which causes the unevenness of the colored light and lowers the quality. This becomes a more prominent problem when the organic EL element is increased in size. Further, when a plurality of dopants are contained, it is technically difficult.

In the formation of the organic layer of the organic EL element, the formation of the organic layer by solution application / film formation (wet process) is attracting attention as a method replacing the current vacuum deposition method (see, for example, Patent Documents 1 and 2). .)

However, in the formation of an organic layer by a wet process, depending on the type of the organic compound, a phenomenon such as crystallization may occur during the formation of the layer. In this case, the external extraction efficiency and the visibility efficiency are deteriorated. As a result, the quality of the organic EL element is deteriorated.

In addition, when a mixed solution of two or more materials is used, there is a problem that it is difficult to form a uniform film due to the solubility and crystallinity of each material in a solvent, drying conditions during film formation, and the like. is there.

In particular, in a phosphorescent organic EL device, since it is necessary to contain two or more kinds of materials, that is, a host and a dopant, in the light emitting layer, the solution of the above problem is extremely important, and the solution is awaited. ing.

JP 2008-244053 A International Publication No. 08/108430

An object of the present invention is to provide an organic electroluminescence element having a high external extraction quantum efficiency, a low driving voltage, and a long lifetime, and an illumination device and a display device including the element.

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

1. In an organic electroluminescence device in which a plurality of constituent layers including two or more light emitting layers are sandwiched between an anode and a cathode,
An organic electroluminescence device, wherein at least two layers of the light emitting layer are manufactured through a process of manufacturing by a wet process.

2. 2. The organic electroluminescent element according to 1 above, wherein at least one of the light emitting layers contains a phosphorescent organometallic complex.

3. 3. The organic electroluminescent device according to 2 above, wherein at least one of the phosphorescent organometallic complexes is a compound represented by the following general formula (1).

[Wherein, P and Q each represent a carbon atom or a nitrogen atom, and A1 represents an atomic group forming an aromatic hydrocarbon ring or an aromatic heterocyclic ring together with PC. A2 represents an atomic group that forms an aromatic heterocycle with QN. P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2. j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M1 represents a group 8-10 transition metal element in the periodic table. ]
4). 4. The organic electroluminescence device as described in 3 above, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (2).

[In formula, Z represents a substituent. P and Q each represent a carbon atom or a nitrogen atom, and A1 represents an atomic group that forms an aromatic hydrocarbon ring or an aromatic heterocyclic ring together with P—C. A3 represents -C (R01) = C (R02)-, -N = C (R02)-, -C (R01) = N- or -N = N-, and each of R01 and R02 represents a hydrogen atom or a substituent. Represents a group. P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2. j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M1 represents a group 8-10 transition metal element in the periodic table. ]
5). 5. The organic electroluminescence device as described in 4 above, wherein the compound represented by the general formula (2) is a compound represented by the following general formula (3).

[Wherein, R03 represents a substituent, R04 represents a hydrogen atom or a substituent, and a plurality of R04 may be bonded to each other to form a ring. n01 represents an integer of 1 to 4. R05 represents a hydrogen atom or a substituent, and a plurality of R04 or a plurality of R05 may be bonded to each other to form a ring. n02 represents an integer of 1 to 2. R06 represents a hydrogen atom or a substituent, and may combine with each other to form a ring. n03 represents an integer of 1 to 4. Z1 represents an atomic group necessary for forming a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocycle together with C—C. Z2 represents an atomic group necessary for forming a hydrocarbon ring or a heterocyclic ring. P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2. j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M1 represents a group 8-10 transition metal element in the periodic table. R04 and R06 and R05 and R06 may be bonded to each other to form a ring. ]
6). 6. The organic electroluminescence device as described in 5 above, wherein the compound represented by the general formula (3) is a compound represented by the following general formula (4).

[Wherein, R03 represents a substituent, R04 represents a hydrogen atom or a substituent, and a plurality of R04 may be bonded to each other to form a ring. n01 represents an integer of 1 to 4. R05 represents a hydrogen atom or a substituent, and a plurality of R05 may be bonded to each other to form a ring. n02 represents an integer of 1 to 2. R06 represents a hydrogen atom or a substituent, and may combine with each other to form a ring. n03 represents an integer of 1 to 3. R07 represents a substituent or a single bond. P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2. j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M1 represents a group 8-10 transition metal element in the periodic table. ]
7). 7. The organic electroluminescence device as described in any one of 2 to 6 above, wherein the phosphorescent organometallic complex is an iridium complex.

8. 8. The organic electroluminescence device according to any one of 1 to 7, wherein the plurality of constituent layers are manufactured through a process of forming by a wet process.

9. 9. The organic electroluminescence device according to any one of 1 to 8, wherein a constituent layer in contact with at least one of the light emitting layers is formed through a step of forming by a wet process.

10. 10. The organic electroluminescence device according to 9, wherein the constituent layer is a layer provided between the light emitting layer and the cathode.

11. 11. The organic electroluminescence device according to any one of 1 to 10, wherein the constituent layers in contact with the light emitting layer are produced through a process in which all are formed by a wet process.

12. 12. The organic electroluminescence device as described in any one of 1 to 11 above, which emits white light.

13. 13. An illuminating device comprising the organic electroluminescence element as described in any one of 1 to 12 above.

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

According to the present invention, an organic electroluminescence element having a high external extraction quantum efficiency, a low driving voltage, and a long lifetime, and an illumination device and a display device including the element can be provided.

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

The organic EL device of the present invention has the structure according to any one of claims 1 to 10 and has high external extraction quantum efficiency, low driving voltage, and long life. An element could be provided. In addition, a display device and a lighting device including the organic electroluminescence element could be provided.

Hereinafter, details of each component of the organic EL element of the present invention will be sequentially described.

The present inventors diligently studied the above problem, and in particular, when the thickness of the film is increased, the above-described non-uniform film is likely to be formed, and when the film thickness is small, it is difficult to form. found.

If the film thickness of the light emitting layer is simply increased and the dopant (also referred to as light emitting dopant) is non-uniformly present, carrier movement in the light emitting layer is hindered, leading to a decrease in external extraction efficiency and an increase in voltage. On the other hand, when an organic EL device having a light emitting layer formed by laminating at least two thin films is manufactured, the external extraction quantum efficiency is high, the driving voltage is low, and the lifetime is long. An organic EL element can be provided.

The organic EL device of the present invention is characterized in that it is produced through a process in which at least two layers of the light emitting layer, which is a constituent layer of the device, are produced by a wet process, and a dopant ( A phosphorescent compound (also referred to as a phosphorescent metal complex or the like) is preferably used as the luminescent dopant), and a compound represented by the general formula (1) (organometallic complex, Also referred to as a metal complex compound.

<< Compound Represented by Formula (1) >>
The phosphorescent metal complex contained in the organic EL device of the present invention is preferably a compound represented by the above general formula (1).

Hereinafter, the compound represented by the general formula (1) will be described. Incidentally, the phosphorescent metal complex represented by the general formula (1) is a preferred embodiment that is contained as a light emitting dopant in the light emitting layer of the organic EL device of the present invention. (The constituent layers of the organic EL device of the present invention will be described in detail later).

In the general formula (1), examples of the aromatic hydrocarbon ring that A1 forms with PC include a benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene ring, Triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, Examples include a pyrene ring, a pyrantolen ring, and anthraanthrene ring.

These rings may further have a substituent described later.

In the general formula (1), the aromatic heterocycle formed by A1 together with P—C includes a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, Benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, carbazole ring, azacarbazole A ring etc. are mentioned.

Here, the azacarbazole ring means one in which at least one carbon atom of the benzene ring constituting the carbazole ring is replaced with a nitrogen atom.

These rings may further have a substituent described later.

In the general formula (1), the aromatic heterocycle formed by A2 together with QN includes an oxazole ring, an oxadiazole ring, an oxatriazole ring, an isoxazole ring, a tetrazole ring, a thiadiazole ring, a thiatriazole ring, Examples include a thiazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, a pyrazole ring, and a triazole ring.

These rings may further have a substituent described later.

(Substituent)
Examples of the substituent include alkyl groups (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group). Group), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, etc.), alkynyl group (eg, ethynyl group, propargyl group, etc.), aromatic hydrocarbon group ( Also referred to as aromatic hydrocarbon ring group, aromatic carbocyclic group, aryl group, etc., for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, Fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.) An aromatic heterocyclic group (for example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzo A thienyl group, a dibenzothienyl group, an indolyl group, a carbazolyl group, a carbolinyl group, a diazacarbazolyl group (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), a quinoxalinyl group, Pyridazinyl group, triazinyl group, quinazoly Group, phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group) Octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group etc.), aryloxy group (eg, phenoxy group, naphthyloxy group etc.), alkylthio group (eg, methylthio group, etc.) Ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.) , Alkoxycarbonyl groups (for example, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl groups (for example, phenyloxycarbonyl group, naphthyloxycarbonyl group) ), Sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl) Group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbonyl) Nyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyl group) Oxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, Pentylcarbonylamino group, cyclohexylcarbonylamino 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) Group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexyl) Ureido group, octylureido group, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group), sulfinyl group ( For example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, Methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridyl group) Sulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethyl) Xylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trimethyl group) Fluoromethyl 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.), and phosphono groups.

In the general formula (1), examples of the bidentate ligand represented by P1-L1-P2 include phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabole, acetylacetone, and picolinic acid. .

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

In the general formula (1), M1 is a transition metal element of group 8 to 10 in the periodic table of elements (also simply referred to as transition metal), and among these, iridium is preferable.

<< Compound Represented by Formula (2) >>
Among the compounds represented by the general formula (1) according to the present invention, the compound represented by the general formula (2) is preferable.

In the general formula (2), the substituent represented by Z has the same meaning as the substituent described in the description of the general formula (1), preferably an aromatic hydrocarbon ring group or an aromatic heterocyclic group. is there.

In the general formula (2), examples of the aromatic hydrocarbon ring formed by A1 together with P—C include, for example, a benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, Naphthacene ring, triphenylene ring, o-terphenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, Examples include a picene ring, a pyrene ring, a pyranthrene ring, and an anthraanthrene ring.

These rings may further have a substituent represented by Z.

In the general formula (2), examples of the aromatic heterocycle formed by A1 together with PC 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, benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, carbazole ring, Examples thereof include a carboline ring and an azacarbazole ring.

These rings may further have a substituent represented by Z.

In -C (R01) = C (R02)-, -N = C (R02)-, and -C (R01) = N- represented by A3 in the general formula (2), each represented by R01 and R02 The substituent is the same as the substituent represented by Z.

Specific examples of the bidentate ligand represented by P1-L1-P2 in the general formula (2) include phenylpyridine, phenylpyrazole, phenylimidazole, phenyltriazole, phenyltetrazole, pyrazabol, acetylacetone, picolinic acid, and the like. Is mentioned.

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

In the general formula (2), the transition metal elements of groups 8 to 10 in the periodic table of elements represented by M1 (also simply referred to as transition metals) in the periodic table of elements represented by M1 in the general formula (1) Synonymous with group 8-10 transition metal elements.

<< Compound Represented by Formula (3) >>
One preferred embodiment of the compound represented by the general formula (2) is a compound represented by the general formula (3).

In the general formula (3), each of the substituents represented by R03, R04, R05, and R06 has the same meaning as the substituent represented by Z in the general formula (2).

In the general formula (3), examples of the 6-membered aromatic hydrocarbon ring formed by Z1 together with C—C include a benzene ring.

These rings may further have a substituent represented by Z in the general formula (2).

In the general formula (3), as the 5-membered or 6-membered aromatic heterocycle formed by Z1 together with C—C, for example, an oxazole ring, an oxadiazole ring, an oxatriazole ring, an isoxazole ring, a tetrazole ring, a thiadiazole And a ring, a thiatriazole ring, an isothiazole ring, a thiophene ring, a furan ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, an imidazole ring, a pyrazole ring, and a triazole ring.

In the general formula (3), the bidentate ligand represented by P1-L1-P2 has the same meaning as the bidentate ligand represented by P1-L1-P2 in the general formula (1). .

In general formula (3), the transition metal elements of Group 8 to Group 10 in the periodic table of elements represented by M1 are the transition metal groups of Group 8 to Group 10 in the periodic table of elements represented by M1 in General Formula (1). Synonymous with metal element.

<< Compound Represented by Formula (4) >>
Furthermore, among the compounds represented by the general formula (3), the compounds represented by the general formula (4) are preferable.

In the general formula (4), the substituents represented by R03, R04, R05, R06, and R07 have the same meaning as the substituent represented by Z in the general formula (2).

In the general formula (4), the bidentate ligand represented by P1-L1-P2 has the same meaning as the bidentate ligand represented by P1-L1-P2 in the general formula (1). .

In the general formula (4), the transition metal elements of groups 8 to 10 in the periodic table of elements represented by M1 are the transition metal groups of groups 8 to 10 in the periodic table of elements represented by M1 in the general formula (1). Synonymous with metal element.

The compound represented by any one of the general formulas (1), (2), (3) or (4) according to the present invention is Eur. J. et al. Chem. 2005, pages 1637-1643 and the like, or a halogen compound corresponding to a nitrogen-containing ring compound or an imidazole compound is reacted, or the corresponding amine and glyoxal and aldehyde described in SYNTHESIS 2003, 17, 2661-2666, etc. It can be synthesized with reference to the reaction of ammonium chloride with ammonium chloride.

Specific examples of the compound represented by any one of the general formulas (1), (2), (3), and (4) according to the present invention (also referred to as a metal complex compound, an organometallic complex, etc.) will be given below. The present invention is not limited to these.

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

The synthesis examples of typical compounds are shown below.

<< Synthesis of Exemplified Compound D-26 >>

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

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

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

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

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

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

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

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

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

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

(I) Anode / light emitting layer unit / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer unit / electron transport layer / cathode (iii) Anode / hole transport layer / light emitting layer unit / hole blocking Layer / electron transport layer / cathode (iv) anode / hole transport layer / light emitting layer unit / hole blocking layer / electron transport layer / cathode buffer layer / cathode (v) anode / anode buffer layer / hole transport layer / light emission Layer unit / hole blocking layer / electron transport layer / cathode buffer layer / cathode Further, the light emitting layer unit has at least two light emitting layers, and has a non-light emitting intermediate layer between the light emitting layers. Also good. 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 constituting the organic EL element of the present invention will be described.

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

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

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

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

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

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

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

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

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

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

The film thickness of the electron transport layer is not particularly limited, but is usually about 5 nm to 5000 nm, preferably 5 nm to 200 nm. This electron transport layer may have a single layer structure composed of one or more of the above materials.

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

<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 organic EL device of the present invention has two or more light emitting layers, and may have any number of layers as long as it is two or more layers.

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

For the production of the light emitting layer, a light emitting dopant or host compound described later is used, for example, a vacuum deposition method, a wet method (also referred to as a wet process, for example, a spin coating method, a casting method, a die coating method, a blade coating method, a roll coating method, Examples thereof include an inkjet method, a printing method, a spray coating method, a curtain coating method, an LB method (Langmuir-Blodgett method) and the like. (When the compound of the present invention is used for a light emitting layer, it is preferably produced by a wet process).

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

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

Fluorescent dopants (also referred to as fluorescent compounds) and phosphorescent dopants (also referred to as phosphorescent emitters, phosphorescent compounds, phosphorescent compounds, etc.) can be used as the luminescent dopant.

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

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

The phosphorescent quantum yield can be measured by the method described in Spectroscopic II, page 398 (1992 edition, Maruzen) of the Fourth Edition Experimental Chemistry Course 7. Although the phosphorescence quantum yield in a solution can be measured using various solvents, the phosphorescence dopant according to the present invention achieves the phosphorescence quantum yield (0.01 or more) in any solvent. That's fine.

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

In the organic EL device of the present invention, at least one of the light-emitting layers contains a phosphorescent organometallic complex (also referred to as a phosphorescent dopant or a phosphorescent dopant). Preferably contains a compound represented by any one of the general formulas (1), (2), (3) or (4) according to the present invention.

Further, in the compound represented by any one of the general formulas (1), (2), (3), or (4) according to the present invention, M1 represents a transition metal element of Group 8 to Group 10 in the periodic table. Of these, iridium is preferred.

In addition, the light-emitting layer according to the present invention may be used in combination with compounds described in the following patent publications.

For example, International Publication No. 00/70655, JP 2002-280178, JP 2001-181616, JP 2002-280179, JP 2001-181617, JP 2002-280180, JP 2001-247859, JP 2002-299060, JP 2001-313178, JP 2002-302671, JP 2001-345183, JP 2002-324679, International publication No. 02/15645, JP 2002-332291 A, JP 2002-50484 A, JP 2002-332292 A, JP 2002-83684 A, JP 2002-540572 A, JP 2002-2002 A. No. 117978, Japanese Patent Laid-Open No. 2002-3385 No. 8, JP-A No. 2002-170684, JP-A No. 2002-352960, WO 01/93642, JP-A No. 2002-50483, JP-A No. 2002-1000047, JP-A No. 2002-173684 Gazette, JP-A-2002-359082, JP-A-2002-175484, JP-A-2002-363552, JP-A-2002-184582, JP-A-2003-7469, JP-T-2002-525808, JP 2003-7471, JP 2002-525833, JP 2003-31366, JP 2002-226495, JP 2002-234894, JP 2002-233506, JP JP 2002-241751 A, JP 2001-31977 A JP, JP 2001-319780, JP 2002-62824, JP 2002-1000047, JP 2002-203679, JP 2002-343572, JP 2002-203678. Etc.

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

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

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

The light-emitting host that can be used in the present invention is not particularly limited, and compounds conventionally used in organic EL devices can be used. Typically, a carbazole derivative, a triarylamine derivative, an aromatic derivative, a nitrogen-containing heterocyclic compound, a thiophene derivative, a furan derivative, an oligoarylene compound or the like having a basic skeleton, or a carboline derivative or a diazacarbazole derivative (here And the diazacarbazole derivative represents one in which at least one carbon atom of the hydrocarbon ring constituting the carboline ring of the carboline derivative is substituted with a nitrogen atom.

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

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

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

In addition, by using a plurality of known compounds used as the phosphorescent dopant, it is possible to mix different light emission, thereby obtaining an arbitrary emission color.

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

In the present invention, it is preferable that any one of the light emitting layers contains a light emitting host represented by the following general formula (5).

In the general formula (5), X represents O, S or NR46. Y4 represents an alkyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, an aralkyl group, an alkenyl group, an alkylamino group, an aralkylamino group, an alkylsilyl group, an arylsilyl group or a halogenated alkyl group.

Among the above, an aryl group or a heteroaryl group is more preferable.

In the general formula (5), R41 to R46 each represents a hydrogen atom, a halogen atom or a substituent. Examples of the substituent represented by R41 to R46 include 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). Group, pentadecyl group, etc.), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, etc.), alkynyl group (eg, ethynyl group, propargyl group, etc.), aromatic carbonization Hydrogen group (also called aromatic hydrocarbon ring group, aromatic carbocyclic group, aryl group, etc., for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, Acenaphthenyl, fluorenyl, phenanthryl, indenyl, pyrenyl, bif Nitryl group, etc.), aromatic heterocyclic groups (for example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazole- 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 (in which one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom) ), Quinoxalinyl group, pyridazinyl group, triazini Group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyl) Oxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group, etc.), aryloxy group (eg, phenoxy group, naphthyloxy group, etc.), alkylthio group (eg, methylthio group) Group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphtho group, etc.) Tilthio group), 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, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino group, phenylcarbonyl Amino 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, dodecylureido group, phenylureido group, naphthylureido group, 2-pyridylaminoureido group), sulfinyl group (for example, Methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group Group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group) Etc.), arylsulfonyl group or heteroarylsulfonyl group (eg, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridylsulfonyl group, etc.), amino group (eg, amino group, ethylamino group, dimethylamino group, butylamino group, Cyclopentylamino group, 2-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (eg fluorine atom, chlorine atom, bromine atom etc.), fluoride Hydrogen halide group (eg, fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (eg, trimethylsilyl group, triisopropylsilyl group) Group, triphenylsilyl group, phenyldiethylsilyl group, etc.), phosphono group and the like.

Further, these substituents and Y4 may be further substituted with the above substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

Among the compounds represented by the general formula (5), a compound represented by the following general formula (6) is more preferable.

In the general formula (6), X represents O or S. Y5, Y51 and Y52 are each an alkyl group, alkoxy group, aryl group, heteroaryl group, aryloxy group, aralkyl group, alkenyl group, alkylamino group, aralkylamino group, alkylsilyl group, arylsilyl group or alkyl halide Represents a group.

Among the above, an aryl group or a heteroaryl group is more preferable.

N51 and n52 represent 0 or an integer of 1 to 2, and n51 + n52 is 0 to 3.

Y5, Y51, and Y52 may be substituted with the above-described substituents. In addition, a plurality of these substituents may be bonded to each other to form a ring.

The compound represented by the general formula (4) or (5) preferably contains at least one carbazolyl group from the viewpoint of carrier transportability.

Specific examples of known light-emitting hosts 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, 2002-343568, 2002-141173, 2002-352957, 2002-203683, 2002-363227, 2002-231453, 2003-3165, 2002-234888, 2003-27048, 2002-255934, 2002-260861, 2002-280183, 2002-299060, 2002 -302516, 2002-305083, 2002-305084, 2002-308837, and the like.

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

"cathode"
On the other hand, as the cathode, a material having a low work function (4 eV or less) metal (referred to as an electron injecting metal), an alloy, an electrically conductive compound, and a mixture thereof as an electrode material is used. Specific examples of such electrode materials include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide (Al ₂ O ₃ ) Mixtures, indium, lithium / aluminum mixtures, rare earth metals and the like.

Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred.

The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering. The sheet resistance as the cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 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.

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

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

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

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

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

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

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

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

<Blocking layer: hole blocking layer, electron blocking layer>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258 and 11-204359, and “Organic EL elements and the forefront of industrialization (published by NTT Corporation on November 30, 1998)” on page 237. 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 transport layer described later can be used as a hole blocking layer according to the present invention, if necessary.

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

The hole blocking layer includes a carbazole derivative, a carboline derivative, a diazacarbazole derivative (herein, a diazacarbazole derivative is a nitrogen atom in which any one of carbon atoms constituting the carboline ring) It is preferable to contain (represented by).

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

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

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

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

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 hole transport layer described later can be used as an electron blocking layer as necessary. The film thickness of the hole blocking layer and the electron transport layer according to the present invention is preferably 3 nm to 100 nm, and more preferably 5 nm to 30 nm.

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

The hole transport material has either hole injection or transport or 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 ' Di (4-methoxyphenyl) -4,4'-diaminobiphenyl; N, N, N ', N'-tetraphenyl-4,4'-diaminodiphenyl ether; 4,4'-bis (diphenylamino) quadriphenyl N, N, N-tri (p-tolyl) amine; 4- (di-p-tolylamino) -4 '-[4- (di-p-tolylamino) styryl] stilbene; 4-N, N-diphenylamino -(2-diphenylvinyl) benzene; 3-methoxy-4'-N, N-diphenylaminostilbenzene; N-phenylcarbazole, and also two described in US Pat. No. 5,061,569 Having a condensed aromatic ring of, for example, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPD), JP-A-4-308 4,4 ′, 4 ″ -tris [N- (3-methylphenyl) -N-phenylamino] triphenylamine in which three triphenylamine units described in Japanese Patent No. 88 are linked in a starburst type ( MTDATA) and the like.

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

Also, JP-A-11-251067, J. Org. Huang et. al. A so-called p-type hole transport material 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.

The film thickness of the hole transport layer is not particularly limited, but is usually about 5 nm to 5 μm, preferably 5 nm to 200 nm. The hole transport layer may have a single layer structure composed of one or more of the above materials.

It is also possible to use a hole transport layer having a high p property doped with impurities. Examples thereof include JP-A-4-297076, JP-A-2000-196140, JP-A-2001-102175, J. Pat. Appl. Phys. 95, 5773 (2004), and the like.

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

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

"anode"
As the anode in the organic EL element, an electrode material made of a metal, an alloy, an electrically conductive compound, or a mixture thereof having a high work function (4 eV or more) is preferably used. Specific examples of such electrode materials include metals such as Au, and conductive transparent materials such as CuI, indium tin oxide (ITO), SnO ₂ , and ZnO.

Alternatively, an amorphous material such as IDIXO (In ₂ O ₃ —ZnO) capable of forming a transparent conductive film may be used. For the anode, these electrode materials may be formed into a thin film by a method such as vapor deposition or sputtering, and a pattern having a desired shape may be formed by a photolithography method, or when pattern accuracy is not 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.

Alternatively, when a material that can be applied such as an organic conductive compound is used, a wet film forming method such as a printing method or a coating method can be used. When light emission is extracted from the anode, it is desirable that the transmittance be greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 nm to 1000 nm, preferably 10 nm to 200 nm.

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

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

On the surface of the resin film, an inorganic film, an organic film or a hybrid film of both may be formed. The water vapor permeability (25 ± 0.5 ° C.) measured by a method according to JIS K 7129-1992. , Relative humidity (90 ± 2)% RH) is preferably 0.01 g / (m ² · 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.

The material for forming the barrier film may be any material that has a function of suppressing the intrusion 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, ceramic substrates, and the like.

The external extraction efficiency at room temperature of light emission of the organic EL element 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.

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

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

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

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

In the phosphorescent organic EL device of the present invention, at least two light emitting layers are applied and formed by a wet method.

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

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

Further, as a dispersion method, it can be dispersed by a dispersion method such as ultrasonic wave, high shearing force dispersion or media dispersion.

After these layers are formed, a thin film made of a cathode material is formed thereon so as to have a thickness of 1 μm or less, preferably in the range of 50 to 200 nm, and a desired organic EL device can be obtained by providing a cathode. .

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

When a DC voltage is applied to the multicolor display device thus obtained, light emission can be observed by applying a voltage of about 2 V to 40 V with the anode being + and the cathode being −0210. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

<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.

The sealing member may be disposed so as to cover the display area of the organic EL element, and may be a concave plate shape or a flat plate shape. 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.

Also, examples of the polymer plate include those formed from polycarbonate, acrylic, polyethylene terephthalate, polyether sulfide, polysulfone and the like.

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

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

Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups of 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 adhesively cured from room temperature to 80 ° C. 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.

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

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

《Light extraction》
The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1) and can extract only about 15% to 20% of the light generated in the light emitting layer. It is generally said. This is because the 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 element, or between the transparent electrode or the 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 for improving efficiency by giving light condensing property to a substrate (Japanese Patent Laid-Open No. 63-314795), a method of forming a reflective surface on the side surface of an element (Japanese Patent Laid-Open No. 1-220394), and light emission from the 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 brightness 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 efficiency of taking out the light from the transparent electrode to the outside increases as the refractive index of the medium decreases.

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.

Also, 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.

It is desirable that the diffraction grating to be introduced 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, the light traveling in all directions is diffracted, and the light extraction efficiency is increased.

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

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

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

<Condenser sheet>
The organic EL 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 light emitting surface By condensing in the front direction, the luminance in a specific direction can be increased.

As an example of a microlens array, quadrangular pyramids having a side of 30 μm and an apex angle of 90 degrees are arranged two-dimensionally on the light extraction side of the substrate. One side is preferably 10 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, it is possible to use, for example, a sheet that has been put to practical use in an LED backlight of a liquid crystal display device. As such a sheet, for example, a brightness enhancement film (BEF) manufactured by Sumitomo 3M Limited can be used.

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

Further, in order to control the light emission angle from the light emitting element, a light diffusion plate / film may be used in combination with the light collecting sheet. For example, a diffusion film (light-up) manufactured by Kimoto Co., Ltd. can be used.

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

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

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

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

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

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

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

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

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

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

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

Display devices and displays include televisions, personal computers, mobile devices, AV devices, teletext displays, information displays in automobiles, and the like. In particular, it may be used as a display device for reproducing still images and moving images, and the driving method when used as a display device for reproducing moving images may be either a simple matrix (passive matrix) method or an active matrix method.

Light sources include home lighting, interior lighting, clock and liquid crystal backlights, billboard advertisements, traffic lights, light sources for optical storage media, light sources for electrophotographic copying machines, light sources for optical communication processors, light sources for optical sensors, etc. The present invention is not limited to these examples.

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

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

The display 1 includes a display unit A having a plurality of pixels, a control unit B that performs image scanning of the display unit A based on image information, and the like.

The control unit B is electrically connected to the display unit A, and sends a scanning signal and an image data signal to each of a plurality of pixels based on image information from the outside, and the pixels for each scanning line respond to the image data signal by the scanning signal. The image information is sequentially emitted to scan the image and display the image information on the display unit A.

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

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

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

The scanning line 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a grid pattern and are connected to the pixels 3 at the orthogonal positions (details are illustrated). Not)

When the scanning signal is applied from the scanning line 5, the pixel 3 receives the image data signal from the data line 6 and emits light according to the received image data.

A full color display can be achieved by appropriately arranging pixels in the red region, the green region, and the blue region on the same substrate.

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

FIG. 3 is a schematic diagram of a pixel.

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

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

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

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

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

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

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

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

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

In the passive matrix method, there is no active element in the pixel 3, and the manufacturing cost can be reduced.

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

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

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

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

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

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

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

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

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

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

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

FIG. 5 shows a schematic diagram of a lighting device, and the organic EL element 101 of the present invention is covered with a glass cover 102 (in the sealing operation with the glass cover, the organic EL element 101 is brought into contact with the atmosphere. And a glove box under a nitrogen atmosphere (in an atmosphere of high-purity nitrogen gas having a purity of 99.999% or more).

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

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

The structure of the compound used in the examples is shown below.

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

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

This substrate was transferred to a nitrogen atmosphere, and a solution in which 50 mg of HT-26 was dissolved in 10 ml of toluene was spin-coated on the hole transport layer at 1000 rpm for 30 seconds to form a thin film on the hole transport layer. did.

Further, ultraviolet light was irradiated for 180 seconds to carry out photopolymerization / crosslinking to form a second hole transport layer having a film thickness of about 25 nm.

On this second hole transport layer, a solution obtained by dissolving 100 mg Host-38, 5 mg D-1 and 5 mg D-24 in 10 ml toluene was formed by spin coating at 1000 rpm for 30 seconds. Filmed.

Further, ultraviolet light was irradiated for 15 seconds while heating at 100 ° C. to cause photopolymerization / crosslinking, and further heating was performed at 150 ° C. for 30 minutes in a vacuum to obtain a light emitting layer having a film thickness of about 50 nm.

Next, a thin film was formed on this light emitting layer by spin coating using a solution obtained by dissolving 50 mg of ET-3 in 10 ml of hexafluoroisopropanol (HFIP) at 1000 rpm for 30 seconds. Furthermore, it vacuum-dried at 60 degreeC for 1 hour, and was set as the electron carrying layer with a film thickness of about 30 nm.

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

<< Production of Organic EL Element 1-2 >>
Similar to the production of the organic EL device 1-1, up to the second hole transport layer was produced. Next, a film obtained by dissolving 100 mg of Host-38 and 10 mg of D-1 in 20 ml of toluene was formed on this second hole transport layer by spin coating at 2000 rpm for 30 seconds.

Further, ultraviolet light was irradiated for 15 seconds while heating at 100 ° C. to cause photopolymerization / crosslinking, followed by heating at 150 ° C. for 1 hour in a vacuum to obtain a first light emitting layer having a thickness of about 20 nm.

Further, a film obtained by dissolving 100 mg of Host-38 and 10 mg of D-24 in 10 ml of toluene was formed on this first light emitting layer by spin coating under the conditions of 2500 rpm and 30 seconds.

Further, ultraviolet light was irradiated for 15 seconds while heating at 100 ° C., photopolymerization and crosslinking were performed, and heating was performed in vacuum at 150 ° C. for 1 hour to obtain a second light emitting layer having a thickness of about 30 nm.

Subsequently, an electron transport layer, a cathode buffer layer, and a cathode were formed in the same manner as in the organic EL element 1-1 to produce an organic EL element 1-2.

<< Preparation of organic EL element 1-3 >>
In the organic EL element 1-2, an organic EL element 1-3 was produced in the same manner except that the material was changed as shown in Table 1.

<< Evaluation of Organic EL Elements 1-1 to 1-3 >>
When evaluating the obtained organic EL elements 1-1 to 1-3, the specific light emission surface of each organic EL element after production was covered with a glass cover, and the glass cover and the glass substrate on which the organic EL element was produced were separated. An epoxy-based photo-curing adhesive (Luxtrac LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealant around the glass cover side that comes into contact with the transparent support substrate so as to overlap the cathode side, and the glass substrate side. Then, it was cured by irradiation with UV light, sealed, and evaluated by forming an illumination device as shown in FIGS.

The organic EL element was evaluated as follows.

(External quantum efficiency)
The organic EL device is allowed to emit light at room temperature (about 23 ° C. to 25 ° C.) under a constant current condition of ^2.5 mA / cm ² , and the light emission luminance (L) [cd / m ² ] immediately after the start of light emission is measured. 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 where the organic EL element 1-1 was 100.

(Voltage)
Light was emitted under a constant current condition of ^2.5 mA / cm ² , and the voltage immediately after the start of light emission was measured. The voltage was expressed as a relative value where the organic EL element 1-1 was 100.

Table 1 shows the obtained results.

From Table 1, it is clear that the device of the present invention has a high external extraction quantum efficiency and a low driving voltage as compared with the comparative device.

Example 2
<< Preparation of organic EL element 2-1 >>
Patterning was performed on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) on which a 100 nm × 100 mm × 1.1 mm glass substrate as a positive electrode on a 100 mm × 100 mm × 1.1 mm glass substrate was formed, and then 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.

The substrate was transferred to a nitrogen atmosphere, and a mixed solution prepared by dissolving 5 mg of the hole transport material 3 and 45 mg of the hole transport material 4 in 10 ml of toluene on the hole transport layer was used at 1000 rpm for 30 seconds. A thin film was formed by spin coating on the hole transport layer.

On this second hole transport layer, spin was performed at 1500 rpm for 30 seconds using a solution of 100 mg Host-52, 0.1 mg D-6 and 10 mg D-25 dissolved in 10 ml dichlorobenzene. A film was formed by a coating method. Furthermore, it heated at 150 degreeC in vacuum for 1 hour, and was set as the 1st light emitting layer with a film thickness of about 50 nm.

This substrate was fixed to a substrate holder of a vacuum deposition apparatus, and the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa, and then ET-8 was deposited to a thickness of 20 nm on the first light emitting layer to form a first electron transport layer. .

Subsequently, 10 nm of ET-7 was deposited on the first electron transport layer to form a second electron transport layer.

Further, 0.5 nm of lithium fluoride was deposited as a cathode buffer layer and 110 nm of aluminum was deposited as a cathode to form a cathode, whereby an organic EL element 2-1 was produced.

<< Preparation of Organic EL Element 2-2 >>: Present Invention Up to the second hole transport layer was prepared in the same manner as the organic EL element 2-1.

Next, a film obtained by dissolving 100 mg of Host-52 and 5 mg of D-6 in 20 ml of dichlorobenzene was formed on this second hole transport layer by spin coating at 2500 rpm for 30 seconds.

Further, heating was performed in vacuum at 150 ° C. for 1 hour to obtain a first light emitting layer having a thickness of about 20 nm.

Further, a film obtained by dissolving 100 mg Host-14 and 10 mg D-25 in 10 ml ethyl acetate on this first light emitting layer by spin coating at 2500 rpm for 30 seconds was used to form a second light emitting layer. A layer was formed.

Subsequently, an electron transport layer, a cathode buffer layer, and a cathode were formed in the same manner as in the organic EL element 2-1, and an organic EL element 2-2 was produced.

<< Preparation of organic EL element 2-3 >>
An organic EL element 2-3 was produced in the same manner as in the production of the organic EL element 2-2 except that the combination of materials was changed as shown in Table 2.

<< Evaluation of organic EL elements 2-1 to 2-3 >>
When evaluating the obtained organic EL elements 2-1 to 2-3, sealing was performed in the same manner as in Example 1, and an illumination device as shown in FIGS. The voltage and life were evaluated.

Incidentally, the evaluation of the light emission lifetime was performed as follows.

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

Table 2 shows the results obtained.

From Table 2, it is clear that the device of the present invention has a high external extraction quantum efficiency, a low driving voltage, and a long life compared to the comparative device.

Example 3
<< Preparation of organic EL element 3-1 >>
Patterning was performed on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) on which a 100 nm × 100 mm × 1.1 mm glass substrate as a positive electrode on a 100 mm × 100 mm × 1.1 mm glass substrate was formed, and then 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.

This substrate was transferred to a nitrogen atmosphere, and a solution obtained by dissolving 50 mg of ADS254BE (American Dye Source) in 10 ml of toluene was spin-coated on the hole transport layer at 1000 rpm for 30 seconds on the hole transport layer. Then, a thin film was formed, and further heated in a vacuum at 60 ° C. for 1 hour to obtain a second hole transport layer having a thickness of about 25 nm.

On this second hole transport layer, a solution prepared by dissolving 100 mg Host-25, 5 mg D-9 and 5 mg D-25 in 10 ml toluene was formed by spin coating at 1000 rpm for 30 seconds. The film was further heated in a vacuum at 100 ° C. for 1 hour to obtain a light-emitting layer having a thickness of about 50 nm.

This substrate was fixed to a substrate holder of a vacuum deposition apparatus, and the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa, and then the electron transporting material 3 was 30 nm on the light emitting layer, and then lithium fluoride was 0 as a cathode buffer layer. An organic EL element 3-1 was fabricated by depositing aluminum at 110 nm as a cathode and depositing 110 nm of aluminum as the cathode.

<< Preparation of organic EL element 3-2 >>
The layers up to the second hole transport layer were prepared in the same manner as the organic EL element 3-1.

Next, a film obtained by dissolving 100 mg of Host-25 and 5 mg of D-9 in 10 ml of toluene was formed on this second hole transport layer by spin coating at 2000 rpm for 30 seconds. Heating was performed in vacuum at 150 ° C. for 1 hour to obtain a first light emitting layer.

A film obtained by dissolving 100 mg Host-16 and 10 mg D-25 in 40 ml hexafluoroisopropanol (HFIP) is formed on the first light-emitting layer by spin coating at 1000 rpm for 30 seconds. And it vacuum-dried at 60 degreeC for 1 hour, and formed the 2nd light emitting layer.

Subsequently, an electron transport layer, a cathode buffer layer, and a cathode were formed in the same manner as in the organic EL element 3-1, and an organic EL element 3-2 was produced.

<< Preparation of organic EL elements 3-3 and 3-4 >>
In the organic EL element 3-2, organic EL elements 3-3 and 3-4 were respectively produced in the same manner except that the combination of materials was changed as shown in Table 3.

<< Evaluation of organic EL elements 3-1 to 3-4 >>
When the obtained organic EL elements 3-1 to 3-4 were evaluated, they were sealed in the same manner as in Example 1 to form an illuminating device as shown in FIGS. 5 and 6, and the same as in Example 2. The external extraction quantum efficiency, voltage, and lifetime were evaluated.

Table 3 shows the obtained results.

From Table 3, it is clear that the device of the present invention has a high external extraction quantum efficiency, a low driving voltage, and a long life compared to the comparative device.

Example 4
<< Preparation of organic EL element 4-1 >>
Patterning was performed on a substrate (NA-45 manufactured by NH Techno Glass Co., Ltd.) on which a 100 nm × 100 mm × 1.1 mm glass substrate as a positive electrode on a 100 mm × 100 mm × 1.1 mm glass substrate was formed, and then 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.

This substrate was transferred to a nitrogen atmosphere, and a solution in which 100 mg of HT-29 was dissolved in 10 ml of toluene was spin-coated on the hole transport layer at 3000 rpm for 30 seconds on the hole transport layer to form a thin film. did.

Further, ultraviolet light was irradiated for 180 seconds to carry out photopolymerization / crosslinking to form a second hole transport layer.

On this second hole transport layer, a solution obtained by dissolving 100 mg of Host-53, 15 mg of D-30 and 0.5 mg of D-10 in 10 ml of toluene was spin-coated at 600 rpm for 30 seconds. Was formed.

Further, ultraviolet light was irradiated for 15 seconds while heating at 100 ° C. to cause photopolymerization / crosslinking, and further heating was performed at 150 ° C. for 30 minutes in a vacuum to obtain a light emitting layer having a film thickness of about 60 nm.

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

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

<< Preparation of organic EL element 4-2 >>
Similarly to the production of the organic EL element 4-1, up to the second hole transport layer was produced.

Next, a film similar to the solution used for forming the light emitting layer in the organic EL element 4-1 was used on this second hole transport layer, and the film was formed by spin coating at 3000 rpm for 30 seconds. While being heated at 100 ° C., ultraviolet light was irradiated for 15 seconds to cause photopolymerization / crosslinking, and further heating was performed in vacuum at 150 ° C. for 30 minutes to obtain a first light emitting layer having a thickness of about 30 nm.

Subsequently, using the same solution, a film was formed on the first light emitting layer by spin coating at 3000 rpm for 30 seconds, and irradiated with ultraviolet light for 15 seconds while heating at 100 ° C. to perform photopolymerization and crosslinking. Further, heating was performed at 150 ° C. for 30 minutes in a vacuum to obtain a second light emitting layer having a thickness of about 30 nm.

Subsequently, an electron transport layer, a cathode buffer layer, and a cathode were formed in the same manner as in the organic EL element 4-1, and an organic EL element 4-2 was produced.

<< Evaluation of Organic EL Elements 4-1, 4-2 >>
When evaluating the obtained organic EL elements 4-1, 4-2, the specific light emission surface of each organic EL element after production was covered with a glass cover, and the glass cover and the glass substrate on which the organic EL element was produced were separated. An epoxy-based photo-curing adhesive (Luxtrac LC0629B manufactured by Toagosei Co., Ltd.) is applied as a sealant around the glass cover side that comes into contact with the transparent support substrate so as to overlap the cathode side, and the glass substrate side. Then, it was cured by irradiation with UV light, sealed, and evaluated by forming an illumination device as shown in FIGS.

The organic EL element was evaluated as follows.

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 where the organic EL element 4-1 was 100.

(Voltage)
Light was emitted under a constant current condition of ^2.5 mA / cm ² , and the voltage immediately after the start of light emission was measured. The voltage was expressed as a relative value where the organic EL element 4-1 was 100.

Table 4 shows the obtained results.

From Table 4, it is clear that the device of the present invention has a high external extraction quantum efficiency and a low driving voltage compared to the comparative device.

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

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

This substrate was transferred to a nitrogen atmosphere, and a solution prepared by dissolving 50 mg of the hole transport material 2 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 perform 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 Host-18 (60 mg), D-1 (3.0 mg) and D-10 (2.0 mg) in 6 ml of toluene was prepared by spin coating under the condition of 2000 rpm and 30 seconds. Filmed. The first light emitting layer was formed by vacuum drying at 60 ° C. for 1 hour.

Further, on this first light emitting layer, a solution in which Host-9 (60 mg) and D-26 (6.0 mg) were dissolved in 6 ml of hexafluoroisopropanol (HFIP) was used, and spin coating was performed at 2000 rpm for 30 seconds. Was formed into a film and vacuum-dried at 60 ° C. for 1 hour to form a second light emitting layer.

This substrate is fixed to a substrate holder of a vacuum evaporation apparatus, and the vacuum chamber is depressurized to 4 × 10 ⁻⁴ Pa, and then the electron transport material 4 is 30 nm on the second light emitting layer, and then lithium fluoride as a cathode buffer layer. The organic EL element 5-1 was manufactured by depositing aluminum with a thickness of 0.5 nm and further depositing aluminum with a thickness of 110 nm as a cathode.

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

DESCRIPTION OF SYMBOLS 1 Display 3 Pixel 5 Scan line 6 Data line 7 Power supply line 10 Organic EL element 11 Switching transistor 12 Drive transistor 13 Capacitor A Display part B Control part 101 Organic EL element 102 Glass cover 105 Cathode 106 Organic EL layer 107 Glass substrate with a transparent electrode 108 Nitrogen gas 109 Water catching agent

Claims

In an organic electroluminescence device in which a plurality of constituent layers including two or more light emitting layers are sandwiched between an anode and a cathode,
An organic electroluminescence device, wherein at least two layers of the light emitting layer are manufactured through a process of manufacturing by a wet process.
2. The organic electroluminescence device according to claim 1, wherein at least one of the light emitting layers contains a phosphorescent organometallic complex.
The organic electroluminescence device according to claim 2, wherein at least one of the phosphorescent organometallic complexes is a compound represented by the following general formula (1).

[Wherein, P and Q each represent a carbon atom or a nitrogen atom, and A1 represents an atomic group forming an aromatic hydrocarbon ring or an aromatic heterocyclic ring together with PC. A2 represents an atomic group that forms an aromatic heterocycle with QN. P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2. j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M1 represents a group 8-10 transition metal element in the periodic table. ]
The organic electroluminescent device according to claim 3, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (2).

[In formula, Z represents a substituent. P and Q each represent a carbon atom or a nitrogen atom, and A1 represents an atomic group that forms an aromatic hydrocarbon ring or an aromatic heterocyclic ring together with P—C. A3 represents -C (R01) = C (R02)-, -N = C (R02)-, -C (R01) = N- or -N = N-, and each of R01 and R02 represents a hydrogen atom or a substituent. Represents a group. P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2. j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M1 represents a group 8-10 transition metal element in the periodic table. ]
The organic electroluminescent device according to claim 4, wherein the compound represented by the general formula (2) is a compound represented by the following general formula (3).

[Wherein, R03 represents a substituent, R04 represents a hydrogen atom or a substituent, and a plurality of R04 may be bonded to each other to form a ring. n01 represents an integer of 1 to 4. R05 represents a hydrogen atom or a substituent, and a plurality of R04 or a plurality of R05 may be bonded to each other to form a ring. n02 represents an integer of 1 to 2. R06 represents a hydrogen atom or a substituent, and may combine with each other to form a ring. n03 represents an integer of 1 to 4. Z1 represents an atomic group necessary for forming a 6-membered aromatic hydrocarbon ring or a 5-membered or 6-membered aromatic heterocycle together with C—C. Z2 represents an atomic group necessary for forming a hydrocarbon ring or a heterocyclic ring. P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2. j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M1 represents a group 8-10 transition metal element in the periodic table. R04 and R06 and R05 and R06 may be bonded to each other to form a ring. ]
The organic electroluminescence device according to claim 5, wherein the compound represented by the general formula (3) is a compound represented by the following general formula (4).

[Wherein, R03 represents a substituent, R04 represents a hydrogen atom or a substituent, and a plurality of R04 may be bonded to each other to form a ring. n01 represents an integer of 1 to 4. R05 represents a hydrogen atom or a substituent, and a plurality of R05 may be bonded to each other to form a ring. n02 represents an integer of 1 to 2. R06 represents a hydrogen atom or a substituent, and may combine with each other to form a ring. n03 represents an integer of 1 to 3. R07 represents a substituent or a single bond. P1-L1-P2 represents a bidentate ligand, and P1 and P2 each independently represent a carbon atom, a nitrogen atom or an oxygen atom. L1 represents an atomic group that forms a bidentate ligand together with P1 and P2. j1 represents an integer of 1 to 3, j2 represents an integer of 0 to 2, and j1 + j2 is 2 or 3. M1 represents a group 8-10 transition metal element in the periodic table. ]
The organic electroluminescence device according to any one of claims 2 to 6, wherein the phosphorescent organometallic complex is an iridium complex.
The organic electroluminescence device according to any one of claims 1 to 7, wherein the plurality of constituent layers are manufactured through a step of forming by a wet process.
9. The organic electroluminescence device according to claim 1, wherein a constituent layer in contact with at least one of the light emitting layers is formed through a step of forming by a wet process.
The organic electroluminescent element according to claim 9, wherein the constituent layer is a layer provided between the light emitting layer and the cathode.
The organic electroluminescence device according to any one of claims 1 to 10, wherein each of the constituent layers in contact with the light emitting layer is manufactured through a step of forming by a wet process.
The organic electroluminescence device according to any one of claims 1 to 11, which emits white light.
An illuminating device comprising the organic electroluminescence element according to any one of claims 1 to 12.
A display device comprising the organic electroluminescence element according to any one of claims 1 to 12.