WO2012063690A1

WO2012063690A1 - Organic electroluminescent element, illumination device, and display device

Info

Publication number: WO2012063690A1
Application number: PCT/JP2011/075246
Authority: WO
Inventors: 秀雄 ▲高▼; 池水　大; 修石毛; 北　弘志
Original assignee: コニカミノルタホールディングス株式会社
Priority date: 2010-11-11
Filing date: 2011-11-02
Publication date: 2012-05-18
Also published as: JPWO2012063690A1; JP5708656B2

Abstract

By means of using an organic electroluminescent element material that enables drying at a low temperature and in a short time period and that has high tolerance to external factors such as water and oxygen, a long-lasting organic electroluminescent element, illumination device, and display device are provided. The organic electroluminescent element has at least one organic-compound layer sandwiched between a positive electrode and a negative electrode, and is characterized by at least one of the organic-compound layers containing nanoparticles, and by the nanoparticles containing a light-emitting dopant compound and a light-emitting host compound having a 0-0 band of phosphorescence that is at or below 460 nm.

Description

Organic electroluminescence element, lighting device and display device

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

An organic electroluminescence element (hereinafter also referred to as an organic EL element) is an all-solid-state element composed of an organic material film having a thickness of only about 0.1 μm between electrodes and emits light of 2V to 20V. Since it can be achieved at a relatively low voltage, it is a technology expected as a next-generation flat display and illumination.

The discovery of an organic EL device using phosphorescence emission enables a light emission efficiency of about 4 times in principle compared to the previous method using fluorescence emission. Research and development related to the structure is performed all over the world (for example, see Patent Document 1 and Non-Patent Documents 1 to 3).

On the other hand, there are two main methods for producing organic EL elements, known as film formation by vacuum evaporation (dry process) and solution coating / film formation (wet process). An excellent wet process is attracting attention in terms of high productivity. In the organic EL elements having a multi-layer structure which is currently in the mainstream, development of a laminating method by coating and a material that can be laminated by coating is required. Especially from the viewpoint of practical use, in terms of solution stability, film forming property, etc. It is still inadequate and further improvement techniques are essential. In particular, the escape from the influence of moisture, oxygen, etc., of the luminescent dopant, which plays the most important role, is an important issue that is closely related to reducing the load on the process environment. Recently, there have been reports on glass capsule light-emitting materials (see, for example, Non-Patent Documents 4 and 5), but there is no suggestion regarding light-emitting dopants in organic electroluminescent devices, and a problem is awaited.

Also, in an organic electroluminescence device produced by solution application / film formation (wet process), the solvent used in the application may remain in the device, which may affect the performance and life of the device. For this reason, in order to remove the solvent, it is necessary to dry for a long time or at a high temperature. However, there are problems such as a decrease in productivity due to a long time drying or damage to the device due to a high temperature. Was.

US Pat. No. 6,097,147

The object of the present invention is to have a high resistance to external factors such as moisture and oxygen, which have been extremely concerned about organic EL performance, and to dry at low temperature in a short time compared to conventional organic EL elements. By using an organic electroluminescent element material that makes it possible to provide a long-life organic electroluminescent element.

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

1. In an organic electroluminescence device having at least one organic compound layer sandwiched between an anode and a cathode, at least one layer of the organic compound layer contains nanoparticles, and the nanoparticles include a light-emitting dopant compound, An organic electroluminescence device comprising a phosphorescent host compound having a 0-0 band of phosphorescence of 460 nm or less.
2. 2. The organic electroluminescence device according to item 1, wherein the light-emitting dopant compound is a nanoparticle obtained by hydrolyzing a compound represented by the following general formula (1) and then polymerizing the compound.

[Wherein, P and Q each represent a carbon atom or a nitrogen atom, and A1 is necessary for forming an aromatic hydrocarbon ring or an aromatic heterocycle together with PC (C represents a carbon atom). Represents an atomic group. A2 represents an atomic group necessary for forming an aromatic heterocyclic ring together with QN (N represents a nitrogen atom). 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 necessary for forming a bidentate ligand together with P1 and P2. r represents an integer of 1 to 3, s represents an integer of 0 to 2, and r + s is 2 or 3. M ₁ represents a group 8-10 transition metal element in the periodic table. X ₁ and X ₂ each independently represent a residue having a polymerizable functional group that is hydrolyzed and then may be the same or different. a and b represent 0 or an integer of 1 or more, but a and b are not 0 at the same time. ]
3. Item 1 or Item 2 is characterized in that the luminescent host compound is a nanoparticle obtained by hydrolyzing a host compound precursor represented by the following general formula (2) and then polymerizing the precursor. The organic electroluminescent element of description.

(In the formula, A, N _(R 1), an oxygen atom, a sulfur atom or a _{_{Si (R 2) (R 3}} ), B 1 ~ B 8 each represents a CR ₄ or N atoms _.R 1 ~ R ₄ represents a hydrogen atom or a substituent, and R ₂ and R ₃ , and adjacent R ₄ may be bonded to each other to form a ring, and a plurality of positions among B ₁ to B ₈ are CR ₄ And each R ₄ may be the same or different, J represents a divalent linking group, R represents an alkyl group, and Y2 represents a simple bond or a divalent linking group. Y3 and Y4 each represent a group derived from a 5-membered or 6-membered aromatic ring, and at least one represents a group derived from an aromatic heterocycle containing a nitrogen atom as a ring-constituting atom. Represents an integer of 4.)
4). Containing a nanoparticle light-emitting material obtained by simultaneously hydrolyzing and then polymerizing the compound represented by the general formula (1) and the host compound precursor represented by the general formula (2). The organic electroluminescence device according to any one of items 1 to 3, wherein:

5. The organic electroluminescence device according to any one of Items 1 to 4, wherein the nanoparticles are nanoparticles obtained by hydrolysis under microwave irradiation and then polymerization.

6. The organic electroluminescence device according to any one of claims 1 to 5, wherein the nanoparticle is contained in a light emitting layer.

7. An illuminating device comprising the organic electroluminescent element according to any one of items 1 to 6.

8. A display device comprising the organic electroluminescence element according to any one of items 1 to 6.

The organic EL element material of the present invention has higher resistance to external factors such as moisture, oxygen, etc., which have been extremely concerned about organic EL performance, and has a low temperature compared to conventional organic EL element materials. High-performance organic EL elements with high cost performance can be provided by production using a wet process that can be dried in a short time.

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.

In the organic EL device of the present invention, by having the configuration according to any one of claims 1 to 8, the external factors such as moisture, oxygen, impurities, etc., which have been extremely concerned about the device performance in the past. On the other hand, high-performance organic EL elements with high cost performance can be provided by production using a wet process that has high resistance and can be dried in a short time at a low temperature.

Specifically, by using nanoparticles containing a light-emitting dopant compound and a light-emitting host compound having a 0-0 band of phosphorescence of 460 nm or less, an organic EL device having a high external extraction quantum efficiency and a long light emission lifetime is provided. In addition, an organic EL element manufactured by the manufacturing method, a display device including the element, and a lighting device can be provided.

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

《Light emitting dopant material》
The light-emitting dopant material according to the present invention is preferably nanoparticles obtained by hydrolyzing the compound represented by the general formula (1) and then polymerizing the compound. The particle size of the nanoparticles is preferably in the range of 1 nm to 100 nm, more preferably in the range of 10 nm to 50 nm.

Here, the particle size of the nanoparticles used in the present invention was measured with a transmission electron microscope (JEM-2010F).

Subsequently, the compound represented by the general formula (1) which is a precursor of the light emitting dopant material according to the present invention will be described.

<< Compound represented by the general formula (1) (also referred to as a light-emitting dopant precursor) >>
In the general formula (1), the residues other than X ₁ and X ₂ are phosphorescent dopant residues (specifically, also referred to as residues derived from the phosphorescent dopant).

Here, the phosphorescent dopant is a compound in which light emission from an excited triplet is observed, specifically, a compound that emits phosphorescence at room temperature (25 ° C.), preferably an element periodic table. And organometallic complexes containing Group 8 to Group 10 metal elements. Although the phosphorescence quantum yield is defined to be a compound of 0.01 or more at 25 ° C., the preferred phosphorescence quantum yield is 0.1 or more.

The phosphorescence quantum yield will be described in the constituent layer of the organic EL element described later.

In the general formula (1), the aromatic hydrocarbon ring formed with PC represented by A1 includes 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 And a ring, a picene ring, a pyrene ring, a pyranthrene ring, and an anthraanthrene ring. Among these, a benzene ring is preferable.

In addition, these rings may further have a substituent described later.

In the general formula (1), examples of the aromatic heterocycle formed with PC represented by A1 include a furan ring, a thiophene ring, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, Pyrazine ring, triazine ring, benzimidazole ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, indazole ring, benzimidazole ring, benzothiophene ring, benzothiazole ring, benzoxazole ring, quinoxaline Ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring, carbazole ring, carboline ring, diazacarbazole ring (a ring in which one of the carbon atoms constituting the carboline ring is further substituted with a nitrogen atom) Etc.) That. These rings may further have a substituent described later.

In the general formula (1), A2 is an aromatic heterocycle formed with QN, for example, an oxazole ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, benzimidazole ring , Oxadiazole ring, triazole ring, imidazole ring, pyrazole ring, thiazole ring, indole ring, indazole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinazoline ring, cinnoline ring, quinoline ring, isoquinoline ring, phthalazine ring , A naphthyridine ring, and the like. These rings may further have a substituent described later.

<< Substituent >>
As the substituent that the aromatic hydrocarbon ring or aromatic heterocyclic ring represented by A1 may have, and the substituent that the aromatic heterocyclic ring represented by A2 may have, Examples of groups include alkyl groups (eg, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, etc.) A cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), an alkenyl group (eg, vinyl group, allyl group, etc.), an alkynyl group (eg, ethynyl group, propargyl group, etc.), an aromatic hydrocarbon group (aromatic hydrocarbon). Also referred to as cyclic group, aromatic carbocyclic group, aryl group, etc., for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group Group, anthryl group, azulenyl group, acenaphthenyl group, fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc., aromatic heterocyclic group (eg pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl) Group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl Group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl Group (of the carbolinyl group) One of the carbon atoms constituting the ruborin ring is replaced by a nitrogen atom), quinoxalinyl group, pyridazinyl group, triazinyl group, quinazolinyl group, phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl) Group, oxazolidyl group, etc.), alkoxy group (for example, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group, octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (for example, cyclopentyloxy group, Cyclohexyloxy group etc.), aryloxy group (eg phenoxy group, naphthyloxy group etc.), alkylthio group (eg methylthio group, ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group etc.), cycl A cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), an arylthio group (eg, phenylthio group, naphthylthio group, etc.), an alkoxycarbonyl group (eg, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, Octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl group (eg, phenyloxycarbonyl group, naphthyloxycarbonyl group, etc.), sulfamoyl group (eg, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, Butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl group 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, dodecyl) Carbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyloxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group) Etc.), an amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, pentylcarbonyl group) 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, 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, etc.), sulfinyl group (for example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group) 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 (eg, 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-ethylhexylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group) Etc.), halogen atoms (eg fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon groups (eg fluoromethyl group, trifluoromethyl group, pentafluoroethyl group, pentafluorophenyl group etc.), cyano group , Nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group, etc.), phosphono group and the like.

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

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

In the general formula (1), L1 represents an atomic group necessary for forming a bidentate ligand together with P1 and P2, r represents an integer of 1 to 3, and s represents an integer of 0 to 2. However, r + s represents 2 or 3, and in the compound represented by the general formula (1), it is particularly preferable that s is 0.

In the general formula (1), as the metal element group 8-10 of the periodic table represented by M _1, M ₁ is a transition metal element of group 8-10 of the periodic table (simply a transition metal both Among them, iridium and platinum are preferable, and iridium is particularly preferable.
Hereinafter, although the specific example of the compound used as the phosphorescence emission dopant residue contained in the compound represented by General formula (1) is shown, this invention is not limited to these.

The compound represented by the general formula (1) is, for example, Inorg. Chem. It can be synthesized by referring to the method described in Vol. 40, 1704-1711.

In the general formula (1), M ₁ represents a metal element, preferably Si, Ti, Ni, W, Zr, Mg, Al, Ge, B, Ga, Sb, Sn, Ta, V, and more. Si, Ti, Ni, Al, Zr and Sn are preferable.

(Group hydrolyzed and then polymerizable)
In the general formula (1), X ₁ and X ₂ represent a functional group that can be hydrolyzed and then polymerized, and preferably an alkoxy group (for example, methoxy group, ethoxy group, isopropyloxy group, propyloxy group, etc.), An amino group etc. are mentioned. a and b represent 0 or an integer of 1 or more, but a and b are not 0 at the same time.

A phosphorescent dopant (simply referred to as a phosphorescent dopant) consisting of phosphorescent particles obtained by hydrolyzing and then polymerizing the compound represented by the general formula (1) according to the present invention, It preferably has semiconducting properties, and preferably has a specific resistance value in the range of 1.0 × 10 ² Ω · cm to 1.0 × 10 ¹⁰ Ω · cm.

(Preferred embodiment of nanoparticles)
Preferred embodiments of the phosphorescent particles obtained by hydrolyzing and then polymerizing the compound represented by the general formula (1) according to the present invention include the pre-CD-1 to pre-CD- described above. Nanoparticles obtained by hydrolyzing a precursor such as 14 and then polymerizing.

Moreover, about the method of manufacturing a crosslinked polymer by hydrolysis of the compound (precursor) represented by the above general formula (1) according to the present invention and subsequent polymerization reaction, for example, 5th edition experimental chemistry course, etc. It is possible to synthesize by referring to the method described in 1.

The step of hydrolyzing and then polymerizing the compound represented by the general formula (1) to obtain the phosphorescent dopant according to the present invention will be described in detail in Example 1 described later. Pre-CD-1 which is a synthetic raw material shown in FIG. 1 is used as a precursor, and the precursor is hydrolyzed and then polymerized to produce CD-1, which is an example of a light-emitting dopant according to the present invention. .

The phosphorescent particles according to the present invention can be used in any constituent layer of the organic electroluminescence device of the present invention, but it is particularly preferable that the phosphorescent particles are used in the light emitting layer.
The constituent layers of the organic electroluminescence element of the present invention will be described later in detail.

Hereinafter, specific examples of the compound represented by the general formula (1) (also referred to as a precursor of the light-emitting dopant material according to the present invention, simply referred to as a precursor) used as a synthesis raw material (precursor) of the light-emitting dopant material according to the present invention. However, the present invention is not limited to these.

(Synthesis of light-emitting dopant material precursor pre-CD-1 according to the present invention)
Hereinafter, synthesis examples of pre-CD-1 which is a specific example of the compound represented by the general formula (1) (precursor of the light-emitting dopant material according to the present invention, also simply referred to as a precursor) will be shown. It is not limited to.

(Process 1)
Iridium chloride n-hydrate (1 mmol in terms of Ir), 4- (2-pyridyl) benzaldehyde (8 mmol, 1.46 g) and 2-phenylquinoline (8 mmol, 1.64 g) in 2-ethoxyethanol (30 ml): water (10 ml) The mixture was heated to reflux in a mixed solvent.

After filtering the precipitated solid. IMIr-1 was obtained by adding sodium borohydride in ethanol.

(Process 2)
Subsequently, IMIr-1 (0.2 mmol, 238 mg) and picolinic acid (0.5 mmol, 62 mg) were heated to reflux in basic 2-ethoxyethanol for 12 hours. The precipitated solid was filtered off to obtain IMIr-2.

(Process 3)
The obtained IMIr-2 (0.2 mmol, 136 mg) and tert-butoxypotassium (1 mmol, 112 mg) were dissolved in anhydrous THF (20 ml), and allyl iodide (2 ml) was added. The mixture was heated to reflux for 12 hours under a nitrogen atmosphere and subjected to normal treatment to obtain IMIr-3.

(Step 4) (Synthesis of pre-CD-1)
IMIr-3 (0.2 mmol, 153 mg) was dissolved in 20 ml of anhydrous methanol, 0.5 ml of trimethoxysilane and platinum / activated carbon (10% Pt) were added, and the mixture was heated to reflux overnight under a nitrogen atmosphere. .

After cooling to room temperature, platinum / activated carbon was filtered off, and the mother liquor was concentrated under reduced pressure to obtain pre-CD-1 (total yield 20%).

<< Host Compound Precursor Represented by Formula (2) (Luminescent Host Compound Precursor) >>
In the general formula (2), a substituent represented by R ₁ to R ₃ in N (R ₁ ) or Si (R ₂ ) (R ₃ ) represented by A, each represented by B ₁ to B ₈ The substituent represented by R ₄ of CR ₄ is represented by the aromatic hydrocarbon ring and aromatic heterocyclic ring formed together with P—C represented by A1 in the general formula (1). It is synonymous with the substituent which may be.

In the general formula (2), as the divalent linking group represented by Y2, an alkylene group (for example, ethylene group, trimethylene group, tetramethylene group, propylene group, ethylethylene group, pentamethylene group, hexamethylene group, 2,2,4-trimethylhexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, cyclohexylene group (for example, 1,6-cyclohexanediyl group, etc.), Cyclopentylene group (for example, 1,5-cyclopentanediyl group and the like), alkenylene group (for example, vinylene group, propenylene group, butenylene group, pentenylene group, 1-methylvinylene group, 1-methylpropenylene group, 2-methylpropenylene group, 1-methylpentenylene group, 3-methyl Pentenylene group, 1-ethylvinylene group, 1-ethylpropenylene group, 1-ethylbutenylene group, 3-ethylbutenylene group, etc.), alkynylene group (for example, ethynylene group, 1-propynylene group, 1-butynylene group, 1-pentynylene group) 1-hexynylene group, 2-butynylene group, 2-pentynylene group, 1-methylethynylene group, 3-methyl-1-propynylene group, 3-methyl-1-butynylene group, etc.), arylene group (for example, o-phenylene group) P-phenylene group, naphthalenediyl group, anthracenediyl group, naphthacenediyl group, pyrenediyl group, naphthylnaphthalenediyl group, biphenyldiyl group (for example, [1,1′-biphenyl] -4,4′-diyl group, 3, 3'-biphenyldiyl group, 3,6-biphenyldiyl group, etc.), tellurium Phenyldiyl group, quaterphenyldiyl group, kinkphenyldiyl group, sexiphenyldiyl group, septiphenyldiyl group, octiphenyldiyl group, nobiphenyldiyl group, deciphenyldiyl group, etc.), heteroarylene group (for example, carbazole) Ring, carboline ring, diazacarbazole ring (also called monoazacarboline ring, which shows a ring structure in which one of carbon atoms constituting carboline ring is replaced by nitrogen atom), triazole ring, pyrrole ring, pyridine ring, pyrazine Ring, quinoxaline ring, thiophene ring, oxadiazole ring, dibenzofuran ring, dibenzothiophene ring, divalent group derived from the group consisting of indole ring, etc.), chalcogen atom such as oxygen and sulfur, 3 or more rings Groups derived from condensed aromatic heterocycles formed by condensation (this Here, the condensed aromatic heterocyclic ring formed by condensing three or more rings is preferably an aromatic heterocyclic ring containing a hetero atom selected from N, O and S as an element constituting the condensed ring. Specifically, acridine ring, benzoquinoline ring, carbazole ring, phenazine ring, phenanthridine ring, phenanthroline ring, carboline ring, cyclazine ring, kindrin ring, tepenidine ring, quinindrin ring, triphenodithia Gin ring, triphenodioxazine ring, phenanthrazine ring, anthrazine ring, perimidine ring, diazacarbazole ring (representing any one of carbon atoms constituting carboline ring replaced by nitrogen atom), phenanthroline ring, dibenzofuran Ring, dibenzothiophene ring, naphthofuran ring, naphthothiophene ring, Nzodifuran ring, benzodithiophene ring, naphthodifuran ring, naphthodithiophene ring, anthrafuran ring, anthradifuran ring, anthrathiophene ring, anthradithiophene ring, thianthrene ring, phenoxathiin ring, thiophanthrene ring (naphthothiophene ring) ) Etc.).

In the general formula (2), a 5-membered or 6-membered aromatic ring used for forming a group derived from a 5-membered or 6-membered aromatic ring represented by Y3 and Y4, respectively, includes a benzene ring, oxazole Examples include a ring, a thiophene ring, a furan ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a diazine ring, a triazine ring, an imidazole ring, an isoxazole ring, a pyrazole ring, and a triazole ring.

Furthermore, at least one of the groups derived from a 5-membered or 6-membered aromatic ring represented by Y3 and Y4 respectively represents a group derived from an aromatic heterocycle containing a nitrogen atom as a ring-constituting atom, As the aromatic heterocycle containing a nitrogen atom as the ring constituent atom, an oxazole ring, a pyrrole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a diazine ring, a triazine ring, an imidazole ring, an isoxazole ring, a pyrazole ring, Examples include a triazole ring.

Further, Y4 as substituent, of the X ₁ and X ₂ as defined is hydrolysed, followed in some cases the substituents having a polymerizable functional group. At least one of Y1 and Y4 is a substituent having a functional group that can be hydrolyzed and then polymerized.

In the general formula (2), the divalent linking group represented by J has the same meaning as Y2, and in the general formula (2), examples of the alkyl group represented by R include a methyl group and an ethyl group. Propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group and the like.

A method for measuring the 0-0 band of phosphorescence in the present invention will be described. First, a method for measuring a phosphorescence spectrum will be described. The luminescent host compound to be measured was dissolved in a well-deoxygenated mixed solvent of ethanol / methanol = 4/1 (vol / vol), put into a phosphorescence measurement cell, and then irradiated with excitation light at a liquid nitrogen temperature of 77K. Then, an emission spectrum at 100 ms is measured after the excitation light irradiation.

Since phosphorescence has a longer emission lifetime than fluorescence, it can be considered that light remaining after 100 ms is almost phosphorescence. Note that for compounds with a phosphorescence lifetime shorter than 100 ms, measurement may be performed with a shorter delay time. However, phosphorescence and fluorescence cannot be separated if the delay time is shortened so that it cannot be distinguished from fluorescence. Therefore, it is necessary to select a delay time that can be separated.

In addition, for a compound that cannot be dissolved in the solvent system, any solvent that can dissolve the compound may be used (substantially, the above-described measuring method has no problem because the solvent effect of the phosphorescence wavelength is negligible).

Next, the 0-0 band is determined. In the present invention, the emission maximum wavelength appearing on the shortest wavelength side in the phosphorescence spectrum chart obtained by the above measurement method is defined as the 0-0 band. . Since the phosphorescence spectrum usually has a low intensity, when it is enlarged, it may be difficult to distinguish between noise and peak.

In such a case, the emission spectrum immediately after the excitation light irradiation (for convenience, this is referred to as a steady light spectrum) is expanded, and the emission spectrum 100 ms after the excitation light irradiation (for convenience, this is referred to as a phosphorescence spectrum) is superimposed. It can be determined by reading the peak wavelength from the stationary light spectrum portion derived from the spectrum.

Also, it is possible to separate the noise and peak by smoothing the phosphorescence spectrum and read the peak wavelength. As the smoothing process, a smoothing method of Savitzky & Golay can be applied.

Specific examples of the host compound according to the present invention are shown below, but the present invention is not limited to these.

In addition, the precursor of the host compound represented by the general formula (2) is disclosed in JP 2007-288035, Chem. Mater. It can be synthesized by referring to known methods described in 2008, 20, 5951, Experimental Chemistry Course 5th Edition (Edited by Chemical Society of Japan).

Next, specific examples of the precursor of the host compound represented by the general formula (2) of the present invention are shown, but the present invention is not limited thereto.

(Synthesis of Pre-CHo-1 Precursor of Luminescent Host Compound According to the Present Invention)

40 ml of toluene, 0.73 g (6 mmol) of trimethoxysilane and 0.018 mmol of a toluene solution of tris (tetramethyldivinyldisiloxane) diplatinum (0) are placed in a three-necked flask and stirred at room temperature with compound (A) 1 20 ml of a toluene solution of .2 g (2 mmol) was added dropwise. After completion of the dropwise addition, the mixture was stirred at 70 ° C. for 3 hours, and then the solvent was removed under reduced pressure to obtain pre-CHo-1. Yield 1.37 g.

<< Method for Manufacturing Organic EL Element >>
In the manufacturing method of the organic EL element of this invention, it is preferable to have the process by which at least 1 layer of the organic compound layer containing the said nanoparticle is formed into a film and formed by a wet method (wet process).

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

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

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

As a method for forming each of these layers, there are a vapor deposition method, a wet process (spin coating method, casting method, ink jet method, printing method), etc., but it is easy to obtain a homogeneous film and it is difficult to generate pinholes. In view of the above, in the present invention, a method of forming and forming a film by a wet method (also referred to as a wet process) is preferable. Examples of the wet method include spin coating, casting, die coating, blade coating, roll coating, and inkjet. , Printing method, spray coating method, curtain coating method, etc., but it is possible to form precise thin films and roll-to-roll such as die coating method, roll coating method, ink jet method, spray coating method, etc. from the viewpoint of high productivity. -A method with high roll system suitability is preferred. Different film forming methods may be applied for each layer.

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, electron transport layer, hole blocking layer, light emitting layer, hole transport layer, hole injection layer, and anode can be produced in the order of the reverse order.

When a DC voltage is applied to the multicolor display device obtained in this way, 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. An alternating voltage may be applied. The alternating current waveform to be applied may be arbitrary.

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

<< Constitutional layer of organic EL element, organic compound layer >>
The constituent layers and organic compound layers of the organic EL device of the present invention will be described. Although the preferable specific example of the layer structure of the organic EL element of this invention is shown below, this invention is not limited to these.

As described above, the phosphorescent particles according to the present invention can be used in any constituent layer of the organic EL device of the present invention, but it is particularly preferable that the phosphorescent particles are used in the light emitting layer.

(I) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (ii) Anode / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode (iii) Anode / hole transport layer / Light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode (iv) anode / anode buffer layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / cathode buffer layer / cathode << Organic compound layer (also called organic layer) >>
The organic compound layer according to the present invention will be described. The organic EL device of the present invention preferably has a plurality of organic compound layers as a constituent layer, and examples of the organic compound layer include a hole transport layer, a light emitting layer, and a hole blocking layer in the above-described layer configuration. As the organic compound layer according to the present invention, an organic compound contained in a constituent layer of the organic EL element, such as a hole injection layer or an electron injection layer, is included. Defined.

Further, when an organic compound is used for the anode buffer layer, the cathode buffer layer, and the like, the anode buffer layer, the cathode buffer layer, and the like each form an organic compound layer.
The organic compound layer includes a layer containing “organic EL element material that can be used for a constituent layer of an organic EL element” or the like.

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

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

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

Each layer constituting the organic EL element of the present invention will be described.

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

The total film thickness of the light emitting layer is not particularly limited, but from the viewpoint of improving the uniformity of the film, preventing unnecessary application of high voltage during light emission, and improving the stability of the emission color with respect to the drive current. It is preferable to adjust in the range of 2 nm to 5 μm, more preferably in the range of 2 nm to 200 nm, and particularly preferably in the range of 10 nm to 20 nm.

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

The light emitting layer of the organic EL device of the present invention preferably contains at least one type of phosphorescent nanoparticle. If necessary, a well-known light-emitting dopant (phosphorescent dopant (also referred to as phosphorescent dopant) or fluorescent dopant), and further, a hole transport material or an electron transport material to be described later may be mixed. It may be used.

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

The light emitting material used in the organic electroluminescence device of the present invention is preferably nanoparticles obtained by hydrolyzing the compound represented by the general formula (1) and then polymerizing it. The average particle diameter of the nanoparticles is 1 nm to 100 nm, preferably 10 nm to 50 nm. In order to produce uniform nanoparticles having a uniform average particle shape, it is preferable to carry out the hydrolysis and subsequent polymerization reaction under microwave irradiation.

A feature of the present invention is that the compound represented by the general formula (1), that is, nanoparticles containing a host molecule by using a host material during the hydrolysis and polymerization of the nanoparticle light-emitting dopant material precursor is used. Or nanoparticles containing a dopant molecule by coexisting a dopant material during hydrolysis and polymerization of a precursor of a host compound represented by the general formula (2), that is, a nanoparticle light-emitting host material precursor Is to use. Hydrolysis and polymerization are carried out in a solvent in which a compound represented by the general formula (1) and a normal host molecule are dissolved, or a precursor of a host compound represented by the general formula (2) and a normal dopant molecule By carrying out hydrolysis and polymerization in a dissolved solvent, and further simultaneously hydrolyzing and polymerizing the precursor of the host compound represented by the general formula (1) and the general formula (2), A particle-emitting material can be obtained. Using nanoparticles prepared by simultaneously hydrolyzing and polymerizing the precursors of the host compounds represented by the general formula (1) and the general formula (2) in that uniform nanoparticles having a constant composition can be prepared. Is preferred.

(Fluorescent dopant (also called fluorescent compound))
Fluorescent dopants (fluorescent compounds) include coumarin dyes, pyran dyes, cyanine dyes, croconium dyes, squalium dyes, oxobenzanthracene dyes, fluorescein dyes, rhodamine dyes, pyrylium dyes, perylene dyes Examples thereof include dyes, stilbene dyes, polythiophene dyes, and rare earth complex phosphors.

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

<< Injection layer: electron injection layer, hole injection layer >>
The injection layer is provided as necessary, and there are an electron injection layer and a hole injection layer, and as described above, it exists between the anode and the light emitting layer or the hole transport layer, and between the cathode and the light emitting layer or the electron transport layer. May be.
An injection layer is a layer provided between an electrode and an organic layer in order to reduce drive voltage and improve light emission luminance. “Organic EL element and its forefront of industrialization (issued by NTT Corporation on November 30, 1998) 2), Chapter 2, “Electrode Materials” (pages 123 to 166) in detail, and includes a hole injection layer (anode buffer layer) and an electron injection layer (cathode buffer layer).

The details of the anode buffer layer (hole injection layer) are described in JP-A-9-45479, JP-A-9-260062, JP-A-8-288069 and the like. As a specific example, copper phthalocyanine is used. Examples thereof include a phthalocyanine buffer layer represented by an oxide, an oxide buffer layer represented by vanadium oxide, an amorphous carbon buffer layer, and a polymer buffer layer using a conductive polymer such as polyaniline (emeraldine) or polythiophene.
The details of the cathode buffer layer (electron injection layer) are described in JP-A-6-325871, JP-A-9-17574, JP-A-10-74586, and the like. Specifically, strontium, aluminum, etc. Metal buffer layer typified by lithium, alkali metal compound buffer layer typified by lithium fluoride, alkaline earth metal compound buffer layer typified by magnesium fluoride, oxide buffer layer typified by aluminum oxide, etc. . The buffer layer (injection layer) is preferably a very thin film, and the film thickness is preferably in the range of 0.1 nm to 10 nm, depending on the material.

<Blocking layer: hole blocking layer, electron blocking layer>
The blocking layer is provided as necessary in addition to the basic constituent layer of the organic compound thin film as described above. For example, it is described in JP-A Nos. 11-204258 and 11-204359, and “Organic EL elements and 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.

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 molecular orbital) level of the compound to the vacuum level, and can be obtained by the following method, for example.

(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. The ionization potential can be obtained as a value obtained by rounding off the second decimal place of a value (eV unit converted value) calculated by performing structural optimization using B3LYP / 6-31G *. This calculation value is effective because the correlation between the calculation value obtained by this method and the experimental value is high.

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

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

Representative examples of aromatic tertiary amine compounds and styrylamine compounds include N, N, N ′, N′-tetraphenyl-4,4′-diaminophenyl; N, N′-diphenyl-N, N′— Bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine (TPD); 2,2-bis (4-di-p-tolylaminophenyl) propane; 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane; N, N, N ′, N′-tetra-p-tolyl-4,4′-diaminobiphenyl; 1,1-bis (4-di-p-tolyl) Aminophenyl) -4-phenylcyclohexane; bis (4-dimethylamino-2-methylphenyl) phenylmethane; bis (4-di-p-tolylaminophenyl) phenylmethane; N, N'-diphenyl-N, N ' 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.

Furthermore, polymer materials in which these materials are introduced into polymer chains or these materials are used as polymer main chains can also be used. In addition, inorganic compounds such as p-type-Si and p-type-SiC can also be used as the hole injection material and the hole transport material.

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, since a higher performance light emitting device can be obtained, the present invention contains a polymerizable compound represented by the general formula (1) or a polymer compound having a structural unit derived from the polymerizable compound. These organic EL element materials are preferably used, and the above materials may be used in combination.

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. However, in the present invention, it is preferably produced by a coating method (wet process). The 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. This 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 hole transport material used for the hole transport layer which concerns on the organic EL element of this invention is shown, this invention is not limited to these.

《Electron transport layer》
The electron transport layer is made of a material having a function of transporting electrons, and in a broad sense, an electron injection layer and a hole blocking layer are also included in the electron transport layer. The electron transport layer can be provided as a single layer or a plurality of layers.
Conventionally, in the case of a single electron transport layer and a plurality of layers, an electron transport material (also serving as a hole blocking material) used for an electron transport layer adjacent to the light emitting layer on the cathode side is injected from the cathode. Any material may be used as long as it has a function of transferring electrons to the light-emitting layer, and any material can be selected from conventionally known compounds.

Examples include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidenemethane derivatives, anthraquinodimethane and anthrone derivatives, oxadiazole derivatives, and the like.

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

Also, metal complexes of 8-quinolinol derivatives such as tris (8-quinolinol) aluminum (Alq), tris (5,7-dichloro-8-quinolinol) aluminum, tris (5,7-dibromo-8-quinolinol) aluminum Tris (2-methyl-8-quinolinol) aluminum, tris (5-methyl-8-quinolinol) aluminum, bis (8-quinolinol) zinc (Znq), 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 be preferably used as the electron transporting material. In addition, the distyrylpyrazine derivative exemplified as the material for the light emitting layer can also be used as an electron transport material, and an inorganic semiconductor such as n-type-Si, n-type-SiC, etc. as in the case of the hole injection layer and the hole transport layer. Can also be used as an electron transporting material. The electron transport layer can be formed by thinning the electron transport material by a known method such as a vacuum deposition method, a spin coating method, a casting method, a printing method including an ink jet method, or an LB method.

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

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

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

"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. The anode may be formed by depositing a thin film of these electrode materials by vapor deposition or sputtering, and a pattern having a desired shape may be formed by photolithography, or when pattern accuracy is not so high (about 100 μm or more) A pattern may be formed through a mask having a desired shape at the time of vapor deposition or sputtering of the electrode material. Or when using the substance which can be apply | coated like an organic electroconductivity compound, wet film-forming methods, such as a printing system and a coating system, can also be used.

When light emission is taken out from the anode, it is desirable that the transmittance is greater than 10%, and the sheet resistance as the anode is preferably several hundred Ω / □ or less. Further, although the film thickness depends on the material, it is usually selected in the range of 10 nm to 1000 nm, preferably 10 nm to 200 nm.

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

Among these, from the point of durability against electron injection and oxidation, etc., a mixture of an electron injecting metal and a second metal which is a stable metal having a larger work function than this, for example, a magnesium / silver mixture, Magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al ₂ O ₃ ) mixtures, lithium / aluminum mixtures, aluminum and the like are preferred. The cathode can be produced by forming a thin film of these electrode materials by a method such as vapor deposition or sputtering.

The sheet resistance as a cathode is preferably several hundred Ω / □ or less, and the film thickness is usually selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm. In order to transmit the emitted light, if either 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 a 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.

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

Preferred examples of the transparent support substrate that can be used include glass, quartz, and a transparent resin film. A particularly preferable support substrate is a resin film capable of giving flexibility to the organic EL element.

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

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

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

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

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

Specific examples of the adhesive include photocuring and thermosetting adhesives having reactive vinyl groups of acrylic acid oligomers and methacrylic acid oligomers, and moisture curing adhesives such as 2-cyanoacrylates. be able to.

In addition, heat- and chemical-curing types (two-component mixing) such as 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. Further, in order to improve the brittleness of the film, it is preferable to have a laminated structure of these inorganic layers and layers made of organic materials.

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

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

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

《Protective film, protective plate》
In order to increase the mechanical strength of the element, a protective film or a protective plate may be provided on the outer side of the sealing film on the side facing the support substrate with the organic layer interposed therebetween or on the sealing film.

Particularly, when the sealing is performed by the sealing film, the mechanical strength is not necessarily high. Therefore, it is preferable to provide such a protective film and a protective plate. As a material that can be used for this, the same glass plate, polymer plate / film, metal plate / film, etc. used for the sealing can be used, but the polymer film is light and thin. Is preferably used.

《Light extraction》
The organic EL element emits light inside a layer having a refractive index higher than that of air (refractive index is about 1.7 to 2.1) and can extract only about 15% to 20% of the light generated in the light emitting layer. It is generally said.

This is because light incident on the interface (interface between the transparent substrate and air) at an angle θ greater than the critical angle causes total reflection and cannot be taken out of the device, or between the transparent electrode or light emitting layer and the transparent substrate. This is because the light is totally reflected between the light and the light is guided through the transparent electrode or the light emitting layer, and as a result, the light escapes in the direction of the element side surface.

As a method of improving the light extraction efficiency, for example, a method of forming irregularities on the surface of the transparent substrate and preventing total reflection at the transparent substrate and the air interface (US Pat. No. 4,774,435), A method 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. Of these, light that cannot go out due to total reflection between layers, etc. is diffracted by introducing a diffraction grating into any layer or medium (inside a transparent substrate or transparent electrode). 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 one 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.

《Condensing sheet》
The organic EL device of the present invention is processed on the light extraction side of the substrate so as to provide, for example, a microlens array structure, or combined with a so-called condensing sheet, for example, with respect to a specific direction, for example, the device light emitting surface. By condensing in the front direction, the luminance in a specific direction can be increased.

As an example of the microlens array, a quadrangular pyramid having a side of 30 μm and an apex angle of 90 degrees is 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 with a triangle stripe having a vertex angle of 90 degrees and a pitch of 50 μm, or the vertex angle is rounded and the pitch is changed randomly. Other shapes may be used.

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 CS-1000 (manufactured by Konica Minolta Sensing) is applied to the CIE chromaticity coordinates.

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

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

The display device of the present invention may be single color 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 inkjet 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 L emitted from the pixel 3 is extracted in the direction of the white arrow (downward).

The scanning line 5 and the plurality of data lines 6 in the wiring portion are each made of a conductive material, and the scanning lines 5 and the data lines 6 are orthogonal to each other in a grid pattern and are connected to the pixels 3 at the orthogonal positions (details are illustrated). Not) When a scanning signal is applied from the scanning line 5, the pixel 3 receives an image data signal from the data line 6 and emits light according to the received image data.

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

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

It is only necessary to provide a mask only when forming a light emitting layer, a hole transport layer, an electron transport layer, etc., and simply arrange them separately by coating with the mask. Since other layers are common, patterning of the mask or the like is not necessary. 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, although an example explains the present invention, the present invention is not limited to these. In addition, although the display of "%" is used in an Example, unless otherwise indicated, "mass%" is represented.

Synthesis Example 1 (Preparation of Nanoparticle Luminescent Material: NP-1)
To ethylene glycol dimethyl ether (600 ml), pre-CD-7 (0.1 mmol, 155 mg) and pre-CHo-1 (0.4 mmol, 289 mg) were added, followed by 0.1 M / l aqueous hydrochloric acid (0.5 ml). And stirred at 33-36 ° C. for 1 hour. Furthermore, 140 degreeC, 500W, and the microwave for 10 minutes were irradiated by temperature priority control. The obtained suspension is recovered by centrifugation, then re-dispersed in absolute ethanol, centrifuged, and the process of removing the supernatant is repeated three times to obtain a nanoparticle light-emitting material NP-1 having an average particle diameter of 30 nm. 178 mg was obtained. Nanoparticle light emitting materials NP-2 to NP-5 shown in Table 1 below were obtained by the same method.

Synthesis Example 2 (Preparation of nanoparticle luminescent material: NP-6)
To ethylene glycol dimethyl ether (600 ml) was added tetramethoxysilane (1.0 ml) and pre-CD-7 (0.1 mmol, 155 mg) and pre-CHo-1 (0.4 mmol, 289 mg) followed by 0.1M. / L hydrochloric acid aqueous solution (0.5 ml) was added, and the mixture was stirred at 33 to 36 ° C. for 1 hour. Furthermore, 140 degreeC, 500W, and the microwave for 10 minutes were irradiated by temperature priority control. The obtained suspension was collected by centrifugation, then redispersed in absolute ethanol, centrifuged, and the process of removing the supernatant was repeated three times to obtain 230 mg of nanoparticle luminescent material NP-6 (average particle size) 35 nm).

Synthesis Example 3 (Nanoparticle Luminescent Material: NP-7)
Pre-CHo-1 (0.4 mmol, 289 mg) and the PD-12 (0.4 mmol, 390 mg) were added to ethylene glycol dimethyl ether (200 ml), followed by 0.1 M / l aqueous hydrochloric acid (0.5 ml). In addition, the mixture was stirred at 33 to 36 ° C. for 1 hour. Furthermore, 140 degreeC, 500W, and the microwave for 10 minutes were irradiated by temperature priority control. The obtained suspension was collected by centrifugation, then redispersed in absolute ethanol, centrifuged, and the process of removing the supernatant was repeated three times to obtain 190 mg of nanoparticle luminescent material NP-7 (average particle size) 40 nm).

Synthesis Example 4 (Nanoparticle Luminescent Material: NP-8)
Pre-CD-7 (0.1 mmol, 155 mg) and the OC-25 (0.8 mmol, 460 mg) were added to ethylene glycol dimethyl ether (200 ml), followed by 0.1 M / l hydrochloric acid aqueous solution (0.5 ml). In addition, the mixture was stirred at 33 to 36 ° C. for 1 hour. Furthermore, 140 degreeC, 500W, and the microwave for 10 minutes were irradiated by temperature priority control. The obtained suspension was collected by centrifugation, redispersed in absolute ethanol, centrifuged, and the process of removing the supernatant was repeated three times to obtain 190 mg of nanoparticle luminescent material NP-8 (average particle size) 40 nm).

Synthesis Example 5 (Comparative Nanoparticle: CNP-1)
Comparative nanoparticle CNP-1 was synthesized in the same manner as in Synthesis Example 1 except that pre-CHo-1 was not added (average particle size 45 nm).

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, 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 30 nm-thick hole transport layer.

On this hole transport layer, a solution prepared by dissolving 30 mg of OC-9 and 3.0 mg of NP-1 in 3 ml of dichloroethane was formed by spin coating under the condition of 2000 rpm for 30 seconds. It dried at 120 degreeC for 1 hour, and was set as the light emitting layer with a film thickness of 50 nm.

On this light emitting layer, a solution of 10 mg of OC-103 dissolved in 3 ml of hexafluoroisopropanol was deposited by spin coating under conditions of 1000 rpm and 30 seconds.

The film was dried by heating at 120 ° C. for 1 hour, an electron transport layer having a thickness of 20 nm was provided, this was attached to a vacuum deposition apparatus, and the vacuum chamber was depressurized to 4 × 10 ⁻⁴ Pa.

A cathode was formed by vapor-depositing 1 nm of potassium fluoride as a cathode buffer layer and 110 nm of aluminum as a cathode to produce an organic EL device 1-1.

<< Preparation of organic EL elements 1-2 to 1-14 >>
Organic EL elements 1-2 to 1-14 were prepared in exactly the same manner as in the preparation of organic EL element 1-1 except that NP-1 used as the nanoparticle light-emitting material was replaced with the compounds shown in Table 2.

In order to clarify the influence of external factors such as oxygen and water on each of the obtained organic EL devices 1-1 to 1-14, detailed examination of the sealing environment and the durability (light emission lifetime) of the device Went.

Specifically, the obtained organic EL elements 1-1 to 1-14 and the non-light-emitting surface are covered with a glass case, and sealed with an epoxy-based photo-curing adhesive (Luxtrac LC0629B manufactured by Toagosei Co., Ltd.). It was.

The relationship of the light emission lifetime of the device was measured when the environment (water concentration and oxygen concentration) of the glove box used for this sealing was changed as shown in Table 3.

The light emission lifetimes of the organic EL elements 1-1 to 1-14 in the glove box environment shown in Table 3 were measured and evaluated as follows.

<Luminescent life>
When driving at 23 ° C. and a constant current of ^2.5 mA / cm ² , the time required for the luminance to drop to half of the luminance immediately after the start of light emission (initial luminance) was measured, and this was calculated as the half-life time (τ0 .5) was used as an index of life.

For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used in the same manner.

The results obtained are shown in Table 4 below. The lifetime in the table is the element No. The light emission lifetime under the condition A of 1-11 is shown as a relative value where the lifetime is 100.

As is apparent from Table 4, the element No. using no nanoparticles was used. It can be seen that the device of the present invention is less affected by the sealing environment than 1-11, 1-12. Comparative element No. in which only the dopant was made into nanoparticles. No. 1-13 and 1-14 In No. 1-13, no light emission was observed because the host material was not contained in the light emitting layer. Comparative element No. 1-14 was hardly affected by the sealing environment in the same manner as the element of the present invention, but the difference from the present invention becomes clear in Example 2 described later.

Example 2
<< Production of Organic EL Elements 1-1 'to 1-14'>>
Organic EL devices 1-1 ′ to 1-14 ′ were produced in the same manner as in Example 1 except that the drying conditions of the light emitting layer and the electron transport layer were changed from 120 ° C. for 1 hour to 100 ° C. for 30 minutes. .

The obtained organic EL elements 1-1 ′ to 1-14 ′ were measured for the sealed emission lifetime under the conditions of the glove box environmental condition A shown in Table 3 of Example 1. Table 5 below shows the ratio of the life of the sample of the environmental condition A in Example 1 to the life of the relative element.

Relative element lifetime of element 1-1 = (element lifetime of element 1-1 ′ / element lifetime of element 1-1) × 100

As is apparent from Table 5, the sample of the present invention is not easily affected by the difference in drying conditions, and can be dried at a low temperature in a short time.

Example 3
Evaluation of External Extraction Quantum Efficiency Devices 1-1 to 1-14 produced in the same manner as in Example 1 were sealed using the sealing condition C (water concentration 1 ppm, oxygen concentration 5 ppm) shown in Table 3 to obtain external extraction quantum. Efficiency was measured.

(External quantum efficiency)
For each device, the external extraction quantum efficiency (%) when a constant current of ^2.5 mA / cm ² was applied at 23 ° C. was measured. For the measurement, a spectral radiance meter CS-1000 (manufactured by Konica Minolta Sensing) was used.

Table 6 shows the obtained results. The measurement results of the external extraction quantum efficiency and the light emission lifetime were evaluated by relative evaluation with the organic EL element 1-11 as 100.

From Table 6, the nanoparticle light-emitting material according to the present invention maintained the external extraction quantum efficiency even in a relatively simple sealing environment.

This makes it possible to manufacture an organic EL element that is strong against the influence of external factors (oxygen and water), which has been a major concern, and the influence of drying conditions, leading to simplification of the manufacturing process. Is clear.

Example 4
<Production of full-color display device>
(Preparation of nanoparticle luminescent material: NP-9, 10)
Based on NP-1 shown in Synthesis Example 1, nanoparticle light-emitting materials NP-9 and 10 shown in Table 7 below were prepared.

(Blue light emitting organic EL device)
The organic EL element 1-1 produced in Example 1 was used.

(Green light-emitting organic EL device)
A green light-emitting organic EL device was prepared in the same manner as in Example 1 except that the nanoparticle light-emitting material was changed from NP-1 to NP-9 in accordance with the organic EL device 1-1 produced in Example 1.

(Red light emitting organic EL device)
A green light-emitting organic EL device was prepared in the same manner as in Example 1 except that the nanoparticle light-emitting material was changed from NP-1 to NP-10 in accordance with the organic EL device 1-1 produced in Example 1.

The red, green and blue light-emitting organic EL elements are juxtaposed on the same substrate to produce an active matrix type full-color display device having the form shown in FIG. 1, and FIG. 2 shows the display of the produced display device. Only the schematic diagram of part A is shown.

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

In this way, a full color display device was produced by juxtaposing the red, green, and blue pixels appropriately.

It was confirmed that by driving the full-color display device, a full-color moving image display having a high luminous efficiency and a long light emission life can be obtained.

Example 5
《Preparation of white light emitting lighting device》
In the production of the organic EL device 1-1 produced in Example 1, the white light-emitting organic EL device 1-1W was similarly performed except that NP-1 was changed to a mixture of NP-1, NP-9, and NP-10. Was made.

The obtained organic EL element 1-1W was covered with a glass case on the non-light emitting surface as described above to obtain a lighting device. The illuminating device could be used as a thin illuminating device that emits white light with high luminous efficiency and long emission life.

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 L Light A Display part B Control part 101 Organic EL element 102 Glass cover 105 Cathode 106 Organic EL layer 107 With a transparent electrode Glass substrate 108 Nitrogen gas 109 Water trapping agent

Claims

In an organic electroluminescence device having at least one organic compound layer sandwiched between an anode and a cathode, at least one layer of the organic compound layer contains nanoparticles, and the nanoparticles include a light-emitting dopant compound, An organic electroluminescence device comprising a phosphorescent host compound having a 0-0 band of phosphorescence of 460 nm or less.
2. The organic electroluminescence device according to claim 1, wherein the light-emitting dopant compound is a nanoparticle obtained by hydrolyzing a compound represented by the following general formula (1) and then polymerizing the compound.

[Wherein, P and Q each represent a carbon atom or a nitrogen atom, and A1 is necessary for forming an aromatic hydrocarbon ring or an aromatic heterocycle together with PC (C represents a carbon atom). Represents an atomic group. A2 represents an atomic group necessary for forming an aromatic heterocyclic ring together with QN (N represents a nitrogen atom). 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 necessary for forming a bidentate ligand together with P1 and P2. r represents an integer of 1 to 3, s represents an integer of 0 to 2, and r + s is 2 or 3. M 1 represents a group 8-10 transition metal element in the periodic table. X 1 and X 2 each independently represent a residue having a polymerizable functional group that is hydrolyzed and then may be the same or different. a and b represent 0 or an integer of 1 or more, but a and b are not 0 at the same time. ]
The said luminescent host compound is a nanoparticle obtained by hydrolyzing the precursor of the host compound represented by following General formula (2), and superposing | polymerizing then, It is characterized by the above-mentioned. Organic electroluminescence device.

(In the formula, A, N (R 1), an oxygen atom, a sulfur atom or a Si (R 2) (R 3 ), B 1 ~ B 8 each represents a CR 4 or N atoms .R 1 ~ R 4 represents a hydrogen atom or a substituent, and R 2 and R 3 , and adjacent R 4 may be bonded to each other to form a ring, and a plurality of positions among B 1 to B 8 are CR 4 And each R 4 may be the same or different, J represents a divalent linking group, R represents an alkyl group, and Y2 represents a simple bond or a divalent linking group. Y3 and Y4 each represents a group derived from a 5-membered or 6-membered aromatic ring, and at least one represents a group derived from an aromatic heterocycle containing a nitrogen atom as a ring-constituting atom. Represents an integer of 4.)
Containing a nanoparticle light-emitting material obtained by simultaneously hydrolyzing and then polymerizing the compound represented by the general formula (1) and the host compound precursor represented by the general formula (2). The organic electroluminescence device according to any one of claims 1 to 3, wherein:
The organic electroluminescence device according to any one of claims 1 to 4, wherein the nanoparticles are nanoparticles obtained by hydrolysis under microwave irradiation and then polymerization.
6. The organic electroluminescence device according to claim 1, wherein the light emitting layer contains the nanoparticles.
An illumination device comprising the organic electroluminescent element according to any one of claims 1 to 6.
A display device comprising the organic electroluminescence element according to any one of claims 1 to 6.