KR20210125915A - Iridium complex-containing composition, organic light emitting device having the same, display apparatus, imaging apparatus, electronic equipment, lighting apparatus, and moving body - Google Patents

Abstract

The present invention provides a composition containing an iridium complex and an isomer of the iridium complex in which the amount of the isomer of the iridium complex is reduced. The iridium complex is a homo-N-trans (HNT) iridium complex having an iridium atom and a first ligand, a second ligand, and a third ligand bonded to the iridium atom. The isomer has the iridium atom, a fourth ligand, a fifth ligand, and the third ligand. The composition ratio of the isomer to the sum of the iridium complex and the isomer is 1.0% or less.

Description

A composition comprising an iridium complex, an organic light emitting device having the same, a display device, an imaging device, an electronic device, a lighting device, and a mobile body TECHNICAL FIELD , LIGHTING APPARATUS, AND MOVING BODY}

The present invention relates to a composition containing an iridium complex with reduced isomerism, an organic light emitting device having the same, a display device, an imaging device, an electronic device, a lighting device, and a moving body.

An organic light emitting device (also called an organic electroluminescent (EL) device or an organic light emitting device) is an electronic device having a first electrode and a second electrode and an organic compound layer disposed between these electrodes. By injecting electrons and holes from these pair of electrodes, excitons of the luminescent organic compound in the organic compound layer are generated, and when these excitons return to the ground state, the organic light emitting element emits light.

In recent years, remarkable progress has been made in organic light-emitting devices, such as, for example, low driving voltage, various emission wavelengths, high-speed responsiveness, and thinning and weight reduction of light-emitting devices.

In order to improve the performance of a light emitting device, development of a light emitting organic compound with higher performance is requested|required, and development is progressing actively in this field|area. The luminescent organic compound is divided into a fluorescent luminescent material and a phosphorescent luminescent material, and in principle, it is known that the phosphorescent luminescent material exhibits higher luminous efficiency than the fluorescent luminescent material.

Japanese Patent Application Laid-Open No. 2009-114137 (hereinafter referred to as PTL 1) describes the following compound A as a phosphorescent material having high luminous efficiency.

In PTL 1, compound A and its synthesis method are described. Although the organic light emitting device having the compound A has been described as a device having high efficiency and long life, the organic light emitting device having the compound A has room for improvement in device lifetime. When Compound A is synthesized by the synthesis method described in PTL 1, Compound A contains about 1.4% of the isomer of Compound A. Due to this isomer, the element lifetime of an organic light emitting element may be shorter than that in the case where such isomer is not included, and it is preferable to reduce this isomer.

The present invention solves the above problems, and provides a composition containing an iridium complex and an iridium complex in which the amount of an isomer of the iridium complex is reduced.

One aspect of the present invention has an iridium atom and a first ligand, a second ligand and a third ligand bonded to the iridium atom, wherein the second ligand has the same structure as the first ligand, and the third ligand is A homo-N-trans (HNT) iridium complex having a structure different from that of the first and second ligands, and the iridium atom, the fourth ligand, the fifth ligand, and the third ligand and wherein the fourth ligand is a ligand represented by the same canonical formula as the first ligand, and the fifth ligand is a ligand represented by the same canonical formula as the second ligand. . The composition ratio of the isomer to the total of the iridium complex and the isomer is 1.0% or less.

Further features of the present invention will become apparent from the following description of embodiments with reference to the accompanying drawings.

1A is a schematic cross-sectional view of an example of a pixel of a display device according to an embodiment of the present invention. 1B is a schematic cross-sectional view of an example of a display device using an organic light emitting device according to an embodiment of the present invention.
2 is a schematic diagram of an example of a display device using an organic light emitting device according to an embodiment of the present invention.
3A is a schematic diagram of an example of an imaging device according to an embodiment of the present invention. 3B is a schematic diagram of an example of a portable device according to an embodiment of the present invention.
4A is a schematic diagram of an example of a display device according to an embodiment of the present invention. 4B is a schematic diagram of an example of a bendable display device.
5A is a schematic diagram of an example of a lighting device according to an embodiment of the present invention. 5B is a schematic diagram of a vehicle as an example of a movable body according to an embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described. The present invention is not limited to the following description, and it is easily understood by those skilled in the art that various changes in form and detail can be made without departing from the spirit and scope of the present invention. That is, the present invention is not interpreted as being limited by the following description.

A composition according to an embodiment of the present invention is a composition comprising a homo-N-trans (HNT) iridium complex and an isomer of the iridium complex. The iridium complex has an iridium atom and a first ligand, a second ligand, and a third ligand bonded to the iridium atom. The second ligand and the first ligand have the same structure, and the third ligand has a different structure from the first and second ligands. The isomer has an iridium atom, fourth and fifth ligands, and the third ligand. The fourth ligand is a ligand represented by the same canonization formula as the first ligand, and the fifth ligand is a ligand represented by the same canonization formula as the second ligand. The composition ratio of the isomer to the total of the iridium complex and the isomer is 1.0% or less. The composition ratio of the isomers is more preferably 0.6% or less. The composition ratio of the isomers is more preferably 0.2% or less.

The iridium complex according to one embodiment of the present invention has an iridium atom, a first ligand, a second ligand, and a third ligand. The first to third ligands are bonded to an iridium atom. The bond may be called a covalent bond or a coordination bond. The first and second ligands have the same structure, and the third ligand has a different structure from the first and second ligands.

The isomer of the iridium complex according to one embodiment of the present invention is a complex having a fourth ligand, a fifth ligand, and a third ligand. The fourth ligand is represented by the same canonization as the first ligand, and the fifth ligand is represented by the same canonization as the second ligand. Since the first and fourth ligands are represented by the same canonical formula as the second and fifth ligands, there are cases where only the substitution position of the substituent and the stereo configuration with respect to Ir are different. Although the properties of the ligands are not significantly different, there are cases where the overall performance of the iridium complex is different. That is, it has been found that an organic light emitting device having excellent device life can be provided by reducing the amount of the isomer by resolving the isomer of the iridium complex as an impurity. When the composition according to an embodiment of the present invention is used as an organic light emitting device, the life of the device is extended because the composition contains fewer isomers.

composition ratio

In this specification, the composition ratio of an isomer is the ratio of the isomer with respect to the sum total of an isomer of an iridium complex and this iridium complex. The composition ratio can be measured, for example, by high performance liquid chromatography (HPLC). More specifically, a spectrum in which the horizontal axis represents the absorption wavelength and the vertical axis represents the absorbance is acquired. Although the excitation wavelength is not specifically limited, 254 nm may be sufficient. From this spectrum and the area defined by the horizontal axis, the amount of the compound can be estimated. And the composition ratio can be computed from the area ratio between the iridium complex and its isomer. The measurement using HPLC is an example, and the method of measuring the composition ratio of the composition according to the present invention is not limited to HPLC.

isomer

The isomers described herein will be described. It is known that structural isomers and stereoisomers exist as isomers.

1. Structural Isomers

The iridium complex has, for example, an iridium atom, a first ligand having a substituent, a second ligand having the same structure as the first ligand, and a third ligand. The definition of "same structure" is that the molecular formula and canonical formula are the same, and the same substituent occupies the same substitution position. Structural isomers have, for example, an iridium atom, a fourth ligand represented by the same canonical formula as the first ligand, and a fifth ligand and a third ligand represented by the same canonical formula as the second ligand. That is, structural isomers satisfy at least one of the following (1) and (2):

(1) The first ligand has a structure different from that of the fourth ligand.

(2) The second ligand has a structure different from that of the fifth ligand.

The first and second ligands may each have a structure having a substituent, and the fourth or fifth ligand may have a structure in which the substitution position of the substituent is different from that of the first or second ligand. Structural isomers may satisfy both (1) and (2).

More specifically, structural isomers have an iridium atom, a fourth ligand having the same structure as the first ligand, a fifth ligand having a substituent at a position different from the second ligand, and a third ligand. In contrast, structural isomers have an iridium atom, a fourth ligand having a substituent at a position different from the first ligand, a fifth ligand having a substituent at a position different from the second ligand, and a third ligand. Here, since the first and fourth ligands are expressed in the same canonization formula, the ligands are not significantly different in terms of the performance of the ligand itself. However, since the ligands form structural isomers, the performance of the iridium complex is often significantly different. The same is true for the second and fifth ligands.

Examples of the structural isomers of the iridium complex and the iridium complex are those represented by the following structural formulas.

2. Stereoisomers

As stereoisomers, optical isomers and geometric isomers are known. The iridium complex has, for example, an iridium atom, a first ligand, a second ligand having the same structure as the first ligand, and a third ligand different from the first and second ligands. A stereoisomer has an iridium atom, a fourth ligand having the same structure as the first ligand, a fifth ligand having the same structure as the second ligand, and a third ligand. The fourth and fifth ligands have fourth and fifth ligands having different configurations for the iridium atom. That is, stereoisomers satisfy at least one of the following (3) and (4):

(3) The steric configuration of the first ligand with respect to the iridium atom is different from the steric configuration of the fourth ligand.

(4) The steric configuration of the second ligand with respect to the iridium atom is different from the steric configuration of the fifth ligand.

Stereoisomers may satisfy both (3) and (4).

Specifically, the iridium complex has an iridium atom, a first ligand, a second ligand, and a third ligand. Stereoisomers have an iridium atom, a fourth ligand, a fifth ligand, and a third ligand. The first, second, fourth and fifth ligands have the same structure. The first, second, fourth and fifth ligands may have different steric configurations for iridium. The third ligand is different in structure from the first, second, fourth and fifth ligands. Although stereoisomers have the same structure, their performance as an iridium complex can vary greatly.

Examples of the iridium complex and the stereoisomer of the iridium complex include those represented by the following structural formula. Here, the ligand is described briefly. The ligand having a carbon atom and a nitrogen atom may have a ring structure, and the ligand having an oxygen atom may have a structure similar to that of an acetylacetone structure. Examples of these ligands are examples and do not exclude other structures.

In the present embodiment, the iridium complex may be a homo-N-trans (HNT) type, and the isomer may be a stereoisomer other than the HNT type.

As a result of extensive research, the present inventors have found that by reducing the amount of these isomers, the device lifetime of an organic light emitting device having the above-described composition can be improved.

iridium complex

Next, an iridium complex according to an embodiment of the present invention will be described. The iridium complex of this embodiment is represented by the following general formula [1] or [2].

In the general formulas [1] and [2], R ¹ to R ¹⁸ are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a cyano group, or a substituted or unsubstituted aromatic group. each independently selected from a hydrocarbon group and a substituted or unsubstituted heteroaromatic group.

Ring A represents a cyclic structure selected from a benzene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring, a 9,9-spirobifluorene ring, a chrysene ring, and a substituted or unsubstituted heteroaromatic group. This cyclic structure may further have a substituent. L represents a bidentate ligand.

IrL is represented by one of the following general formulas [3] to [5].

In the general formulas [3] to [5], R ¹⁹ to R ³³ are each independently selected from a hydrogen atom, an alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted heteroaromatic group.

The iridium complex of the present embodiment may be an iridium complex represented by the general formula [6].

In the general formula [6], R ³⁴ to R ⁴⁸ are each independently selected from a hydrogen atom and a substituted or unsubstituted alkyl group. R ⁴² to R ⁴⁵ may combine with each other to form a ring structure. Specifically, when R ⁴² to R ⁴⁵ are bonded ^{, including a benzene ring having R 42} to R ⁴⁵ , a naphthalene ring, a fluorene ring, a phenanthrene ring, a 9,9-spirobifluorene ring, or a chrysene ring You may form a ring.

In the iridium complex contained in the composition of the present embodiment, in the general formula [6], R ⁴⁵ is an alkyl group and R ⁴³ is a hydrogen atom, and the isomer of the iridium complex contained in the composition is R in the general formula [6] ⁴⁵ may be a hydrogen atom and R ⁴³ may be an alkyl group. The alkyl group represented by R ⁴³ or R ⁴⁵ may be a methyl group.

In the iridium complex contained in the composition of the present embodiment, in the general formula [6], R ³⁷ may be a cyano group.

In the present embodiment, the halogen atom is one of fluorine, chlorine, iodine and bromine. Among these, fluorine is preferable.

In this embodiment, the alkyl group may be a _{C 1-20 alkyl group.} The alkyl group may have a halogen atom as a substituent. The halogen atom may be fluorine. The alkyl group may be a _{C 1-8} alkyl group or a C _{1-4 alkyl group.} When the halogen atom is a substituent, any of the hydrogen atoms of the alkyl group may be substituted, but a trifluoromethyl group may be formed.

More specifically, Examples of the alkyl group include a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a tertiary butyl group, a secondary butyl group, an octyl group, a cyclohexyl group, a 1-adamantyl group and a 2-adamantyl group. can, but is not limited to these.

In this embodiment, the alkoxy group may be a _{C 1-20 alkoxy group.} The alkoxy group may be a _{C 1-6 alkoxy group.} More specifically, examples of the alkoxy group include, but are not limited to, a methoxy group, an ethoxy group, a propoxy group, a 2-ethyl-octyloxy group and a benzyloxy group.

In this embodiment, the aromatic hydrocarbon group may be a _{C 6-18 aromatic hydrocarbon group.} More specifically, examples of the aromatic hydrocarbon group include, but are not limited to, a phenyl group, a naphthyl group, an indenyl group, a biphenyl group, a terphenyl group, a fluorenyl group, a phenanthryl group and a triphenylenyl group.

In the present embodiment, the heteroaromatic group may be a _{C 3-15 heteroaromatic group.} The heteroaromatic time may have a nitrogen atom, an oxygen atom, a sulfur atom, and a combination thereof as a hetero atom. More specifically, examples of the heteroaromatic group include a pyridyl group, a pyrimidyl group, a pyrazyl group, a triazyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, an oxazolyl group, and an oxadia group. Although a zolyl group, a thiazolyl group, a thiadiazolyl group, a carbazolyl group, an acridinyl group, and a phenanthrolyl group are mentioned, It is not limited to these.

The above-described alkyl group, alkoxy group, aromatic hydrocarbon group and heteroaromatic group may have an additional substituent. _{Examples of the additional substituent include a C 1-4} alkyl group such as a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group and a tertiary butyl group, an aralkyl group such as a benzyl group, and an aromatic hydrocarbon group such as a phenyl group and a biphenyl group. , heterocyclic groups such as pyridyl group and pyrrolyl group, dimethylamino group, diethylamino group, dibenzylamino group, diphenylamino group, ditolylamino group, alkoxy group such as methoxy group, ethoxy group and propoxy group, phenoxy group Although aryloxy groups, such as these, halogen atoms, such as fluorine, chlorine, bromine and iodine, and a cyano group, are mentioned, It is not limited to these.

Hereinafter, the specific structural formula of the iridium complex of the present invention is exemplified.

Among the above exemplary compounds, compounds (1) to (64) and compounds (79) to (94) are iridium complexes having a ligand represented by the general formula [5]. Each of these iridium complexes contains one acac-based ligand (diketone-based bidentate ligand) having a small molecular weight. Since the molecular weight of the complex itself is relatively small, purification by sublimation is easy. Moreover, in the general formula [5], R ³¹ to R ³³ preferably each represent a hydrogen atom or an alkyl group, and R ³² more preferably represents a hydrogen atom.

Among the exemplary compounds, compounds (65) to (71) are iridium complexes having a ligand represented by the general formula [4]. Each of these iridium complexes contains one picolinic acid derivative as a ligand in the molecule. Here, when a picolinic acid derivative is introduced as a ligand, the emission peak wavelength of the complex itself can be shifted toward a shorter wavelength compared to the case where an acac-based ligand is introduced.

Among the exemplary compounds, compounds (72) to (78) are iridium complexes having a ligand represented by the general formula [3]. Each of these iridium complexes contains one phenylpyridine (ppy) derivative in the molecule. Since the ligand ppy is a non-luminescent ligand in this iridium complex, red light emission derived from an arylbenzo[f]isoquinoline ligand can be obtained from the iridium complex. Quantum yield is sometimes high by having a ppy ligand.

Method for reducing the amount of isomers

The amount of the isomer of the iridium complex of the present embodiment can be reduced by performing sublimation purification, recrystallization, dispersion washing, GPC purification, and column purification a plurality of times. Regarding the above purification treatment, one type of treatment may be performed a plurality of times, or two or more types of treatment may be combined. In the synthesis of the iridium complex, the composition ratio of the isomers can also be reduced by extraction using the difference between the solubility of the iridium complex and the solubility of the isomer of the iridium complex.

An organic compound layer inside an organic light emitting device according to an embodiment of the present invention

Next, the organic compound layer inside the organic light emitting device according to an embodiment of the present invention will be described.

The organic light emitting device according to the present embodiment has at least a first electrode and a second electrode constituting a pair of electrodes, and an organic compound layer disposed between these electrodes. In the organic light emitting device of the present embodiment, the organic compound layer may be a single layer or a laminate composed of multiple layers as long as it has a light emitting layer. The pair of electrodes may be composed of an anode and a cathode.

Here, when an organic compound layer is a laminated body which consists of multiple layers, the organic compound layer may have a light emitting layer. The organic compound layer may have a hole injection layer, a hole transport layer, an electron blocking layer, a hole exciton blocking layer, an electron transport layer, an electron injection layer, etc. other than a light emitting layer. The light emitting layer may be a single layer or a laminate composed of a plurality of layers. The hole transport layer and the electron transport layer are also called charge transport layers.

In the organic light-emitting device of the present embodiment, at least one layer of the organic compound layer contains the composition according to the present embodiment. Specifically, the composition according to the present embodiment is included in one of the aforementioned hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole exciton blocking layer, electron transport layer and electron injection layer, or may be included in the light emitting layer. .

When the light emitting layer of the organic light emitting device of the present embodiment contains the composition according to the present embodiment, the light emitting layer is a layer made of only the composition of the present embodiment, or in addition to the composition of the present embodiment, the first organic compound and the first organic compound A layer containing a second organic compound different from The first organic compound may have a minimum triplet excitation energy greater than the minimum triplet excitation energy of the iridium complex contained in the composition. The second organic compound may have a minimum triplet excitation energy that is equal to or greater than the minimum triplet excitation energy of the iridium complex contained in the composition and is equal to or less than the minimum triplet excitation energy of the first organic compound. Here, when the light emitting layer includes the first organic compound and the second organic compound, the first organic compound may be a host of the light emitting layer. The second organic compound may be an assist material. The iridium complex contained in the composition may be a guest or a dopant.

Here, the host is a compound having the largest weight ratio among the compounds constituting the light emitting layer. In addition, a guest or a dopant is a compound which weight ratio is smaller than a host among the compounds which comprise a light emitting layer, and is a compound which mainly bears light emission. The assisting material is a compound having a weight ratio smaller than that of the host among the compounds constituting the light emitting layer, and is a compound that assists the light emission of the guest. The assist material is also called a second host.

Here, when the iridium complex of the present embodiment is used as a guest in the light emitting layer, the guest concentration with respect to the entire light emitting layer is preferably 0.01% by weight or more and 20% by weight or less, and more preferably 0.1% by weight or more and 5.0% by weight or less. The whole light emitting layer represents the total weight of the compound which comprises a light emitting layer.

The inventors of the present invention have made various studies and have found that, when the iridium complex contained in the composition of the present embodiment is used as a guest of the light emitting layer, high luminance light output is achieved with high efficiency, and an element with very high durability can be obtained. This light-emitting layer may be a single layer or multiple layers, and by adding a light-emitting material which emits light of a different light-emitting color, it is also possible to mix the light emission color of blue, which is the light emission color of the present embodiment, and another color. The multilayer shows the state in which the light emitting layer and the other light emitting layer are laminated|stacked. In this case, the emission color of the organic light emitting device is not limited to blue. More specifically, the emission color may be white or an intermediate color. When the emission color is white, a separate emission layer emits colors other than blue, that is, red and green. The film is formed by vapor deposition or application.

The organic compound of this embodiment can be used as a constituent material of organic compound layers other than the light emitting layer which comprises the organic light emitting element of this embodiment. Specifically, the organic compound may be used as a constituent material of an electron transport layer, an electron injection layer, a hole transport layer, a hole injection layer, a hole blocking layer, and the like. In this case, the emission color of the organic light emitting device is not limited to blue. More specifically, the emission color may be white or an intermediate color.

In the case of manufacturing the organic light emitting device of the present embodiment, if necessary, well-known low-molecular- and high-molecular-type hole-injecting compounds or hole-transporting compounds, host compounds, light-emitting compounds, electron injecting compounds, or electron-transporting compounds, etc. Can be used in combination.

Examples of these compounds are given below.

As the hole injection injection/transport material, a material with high hole mobility capable of facilitating injection of holes from the anode and transporting the injected holes to the light emitting layer can be used. In order to reduce deterioration of film quality such as crystallization in an organic light emitting device, a material having a high glass transition point temperature can be used. Examples of low molecular weight and high molecular weight materials having hole injection/transport performance include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly( thiophene) and other conductive polymers. The above hole injecting/transporting material is also suitably used for the electron blocking layer.

Specific examples of the compound used as the hole injecting/transporting material are shown below, but of course, it is not limited to these examples.

Among the hole transporting materials described above, HT16 to HT18 can reduce the driving voltage when used in the layer in contact with the anode. HT16 is widely used in organic light emitting devices. You may use HT2, HT3, HT10, HT12 for the organic compound layer adjacent to HT16. You may use two or more materials for one organic compound layer. For example, a combination of HT2 and HT4, a combination of HT3 and HT10, and a combination of HT8 and HT9 may be used.

In addition to the iridium complex of one embodiment of the present invention, examples of the light emitting material having a light emitting function include condensed ring compounds (eg, fluorene derivatives, naphthalene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, anthracene derivatives and rubrene), quinacridone derivatives, coumarin derivatives, stilbene derivatives, organoaluminum complexes such as tris(8-quinolinolato)aluminum, iridium complexes, platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes, and polymer derivatives such as poly(phenylenevinylene) derivatives, poly(fluorene) derivatives and poly(phenylene) derivatives.

Specific examples of the compound used as the light emitting material are shown below, but of course, it is not limited to this example.

Examples of the light emitting layer host or light emitting assist material included in the light emitting layer include, in addition to aromatic hydrocarbon compounds or derivatives thereof, carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, tris(8-quinolinolato)aluminum, etc. an organoaluminum complex, and an organic beryllium complex.

In particular, the host material may have, in its molecular skeleton, an anthracene, tetracene, perylene, fluorene, or pyrene skeleton. This is because, as described above, the material is composed of hydrocarbons, and moreover, it has S1 energy capable of causing sufficient energy transfer in the organic compound of the present invention.

The host material of the aromatic hydrocarbon compound may be a compound represented by the following general formula [7].

Ar1-(Ar2)p-(Ar3)q-Ar1 general formula [7]

In general formula [7], p and q each represent 0 or 1, or p+q is 1 or more.

Ar1 is one substituent selected from the following substituent group α.

Ar2 and Ar3 are each one substituent selected from the following substituent group (beta). Ar2 and Ar3 may be the same or different.

Specific examples of the compound used as the light emitting layer host or light emitting assist material contained in the light emitting layer are shown below, but are not limited to these examples.

The electron-transporting material can be arbitrarily selected from materials capable of transporting electrons injected from the cathode to the light-emitting layer, and is selected, for example, in consideration of the balance with the hole mobility of the hole-transporting material. Examples of the material having electron transport performance include oxadiazole derivatives, oxazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, organoaluminum complexes, and condensed ring compounds. (For example, a fluorene derivative, a naphthalene derivative, a chrysene derivative, and an anthracene derivative) are mentioned. The above-described electron-transporting material is also suitably used for the hole blocking layer.

Specific examples of the compound used as the electron-transporting material are shown below, but are not limited to these examples.

The electron-injecting material can be arbitrarily selected from materials capable of easily injecting electrons from the cathode, and is selected in consideration of, for example, a balance with hole-injecting properties. Other examples of organic compounds include n-type dopants and reductive dopants. Examples of these include compounds containing alkali metals such as lithium fluoride, lithium complexes such as lithium quinolinol, benzimidazolidene derivatives, imidazolidene derivatives, fluvarene derivatives, and acridine derivatives. have.

Composition of organic light emitting device

The organic light emitting element is provided by forming a first electrode, an organic compound layer, and a second electrode on an insulating layer on a substrate. On the second electrode, a protective layer, a color filter, or the like may be disposed. In the case of forming a color filter, a planarization layer may be formed between the color filter and the protective layer. The planarization layer may be made of an acrylic resin or the like. One of the first electrode and the second electrode may be an anode, and the other may be a cathode.

Board

Examples of the substrate include a substrate made of quartz, glass, silicon wafer, resin, metal, or the like. Moreover, on a board|substrate, switching elements, such as a transistor, and wiring may be provided, and an insulating layer may be provided on it. The insulating layer may be formed of any material as long as a contact hole can be formed in order to ensure conduction between the anode and the wiring and insulation can be ensured from the wiring not connected. Examples of this material include resins such as polyimide, silicon oxide, and silicon nitride.

electrode

A pair of electrodes can be used as the electrodes. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light emitting element emits light, an electrode having a high potential is an anode, and the other electrode is a cathode. In other words, the electrode supplying holes to the light emitting layer is an anode, and the electrode supplying electrons is a cathode.

The material constituting the anode may have a work function as large as possible. Examples of such materials include simple metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten, mixtures thereof, alloys formed by combining these, tin oxide, zinc oxide and metal oxides such as indium oxide, indium tin oxide (ITO), and indium zinc oxide. In addition, conductive polymers such as polyaniline, polypyrrole and polythiophene can also be used.

These electrode substances may be used individually or in combination. The anode may be composed of one layer or two or more layers.

When the electrode is used as a reflective electrode, chromium, aluminum, silver, titanium, tungsten, molybdenum, or an alloy thereof, a laminate structure thereof, or the like can be used. When using an electrode as a transparent electrode, although oxide transparent conductive layers, such as an indium tin oxide (ITO) or an indium zinc oxide layer, can be used, it is not limited to these. The electrode may be formed by a photolithographic technique.

The material constituting the cathode may have a small work function. Examples thereof include alkali metals such as lithium, alkaline earth metals such as calcium, simple metals such as aluminum, titanium, manganese, silver, lead and chromium, and mixtures containing these metals. An alloy composed of a combination of these single metals can also be used. Examples of alloys include magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper and zinc-silver. It is also possible to use a metal oxide such as indium tin oxide (ITO). These electrode materials may be used alone or in combination. The negative electrode may have a single layer configuration or a multilayer configuration. In particular, silver can be used, and in order to suppress agglomeration of silver, a silver alloy is more preferable. As long as silver agglomeration can be suppressed, the proportion of the alloy is not affected. For example, this ratio may be 1:1.

The negative electrode is not particularly limited. For example, a top emission element may be formed using oxide conductive layers, such as ITO, as a cathode, or a bottom emission element may be formed using reflective electrodes, such as aluminum (Al). The method of forming the cathode is not particularly limited, but DC and AC sputtering methods and the like provide good film coverage and low resistance.

protective layer

You may arrange|position a protective layer on the cathode. For example, by adhering glass having a desiccant on the cathode, the penetration of water or the like into the organic compound layer can be reduced, and the occurrence of display defects can be reduced. In another embodiment, a passivation film of silicon nitride or the like may be formed on the cathode to reduce penetration of water or the like into the organic EL layer. For example, after the cathode is formed, the protective layer may be formed by transferring the cathode to another chamber without breaking the vacuum, and forming a silicon nitride film having a thickness of 2 μm by CVD. After the film formation by the CVD method, the protective layer may be formed by an atomic layer deposition method (ALD method).

color filter

A color filter may be formed on the protective layer. For example, a color filter in consideration of the size of the organic light emitting element is disposed on another substrate, and the substrate is attached to the substrate on which the organic light emitting element is installed, or alternatively, the color filter is formed by photolithography patterning on the above-described protective layer. may be formed. The color filter may be composed of a polymer.

planarization layer

A planarization layer may be formed between the color filter and the protective layer. The planarization layer may be comprised of an organic compound, and may have a low molecular weight or high molecular weight. The planarization layer may have a high molecular weight.

A flattening layer may be provided above and below a color filter, and these two planarizing layers may be comprised with the same material. Specific examples of this material include polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin and urea resin.

counter substrate

A counter substrate may be disposed on the planarization layer. The opposing substrate is so called because it is disposed at a position facing the above-mentioned substrate. The counter substrate may be made of the same material as the substrate described above. When the above-described substrate is defined as the first substrate, the opposite substrate may be defined as the second substrate.

Formation of organic compound layer

An organic compound layer (a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, etc.) constituting the organic light emitting device according to an embodiment of the present invention is formed by the method shown below. do.

The organic compound layer constituting the organic light emitting device according to an embodiment of the present invention may be formed by a dry process such as vacuum deposition, ionization deposition, sputtering, or plasma. Instead of the dry process, a wet process including a step of forming a layer by dissolving a material in a suitable solvent and performing a known coating method (eg, spin coating, dipping, casting, LB method, inkjet method, etc.) may be used. may be

When the layer is formed by a vacuum deposition method, a solution coating method, or the like, crystallization is difficult to occur and the stability over time is excellent. In the case of forming a film by a coating method, a film can be formed by combining an appropriate binder resin and material.

Specific examples of the binder resin include polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin. It is not limited.

Regarding these binder resins, as a homopolymer or a copolymer, you may use individually by 1 type of resin, or may mix and use 2 or more types. Additives, such as a well-known plasticizer, antioxidant, and a ultraviolet absorber, can be used together as needed.

Use of an organic light emitting device according to an embodiment of the present invention

The organic light-emitting device according to an embodiment of the present invention can be used as a constituent member of a display device or a lighting device. In addition, the organic light emitting element is used in an exposure light source of an electrophotographic image forming apparatus, a backlight of a liquid crystal display, and a light emitting apparatus composed of a white light source and a color filter.

The display apparatus may be an image information processing apparatus which has an image input unit for inputting image information from an area CCD, a linear CCD, a memory card, or the like, and an information processing unit for processing the input information, and displays the input image on the display unit.

The display unit of the imaging device or the inkjet printer may have a touch panel function. The driving method of this touch panel function may be an infrared method, a capacitive method, a resistive film method, or an electromagnetic induction method, and is not particularly limited. The display device may be used in the display section of a multi-function printer.

Next, a display device according to the present embodiment will be described with reference to the drawings.

Fig. 1A is a schematic cross-sectional view of an example of a pixel constituting the display device of the present embodiment. A pixel has 10 sub-pixels. Sub-pixels are divided into 10R, 10G, and 10B according to their emission. The emission color may be distinguished based on the wavelength emitted from the light emitting layer, or the light emitted from the sub-pixel may be selectively transmitted or color-converted by a color filter or the like. Each sub-pixel is, on the interlayer insulating layer 1, a reflective electrode 2 as the first electrode, an insulating layer 3 covering the ends of the reflective electrode 2, and an organic compound layer covering the first electrode and the insulating layer ( 4), a transparent electrode (5), a protective layer (6), and a color filter (7).

The interlayer insulating layer 1 may have a transistor and a capacitor disposed therein or as a lower layer thereof. The transistor and the first electrode may be electrically connected through a contact hole (not shown) or the like.

The insulating layer 3 is also called a bank or a pixel separation film. The insulating layer 3 covers the end of the first electrode and surrounds the first electrode. A portion where the insulating layer is not disposed is in contact with the organic compound layer 4 and becomes a light emitting region.

The organic compound layer 4 has a hole injection layer 41 , a hole transport layer 42 , a first light emitting layer 43 , a second light emitting layer 44 , and an electron transport layer 45 .

The second electrode 5 may be a transparent electrode, a reflective electrode, or a transflective electrode.

The protective layer 6 reduces penetration of moisture into the organic compound layer. Although the protective layer 6 is shown as one layer in the figure, the protective layer 6 may be multiple layers. An inorganic compound layer and an organic compound layer may be provided for each layer.

The color filter 7 is divided into 7R, 7G, and 7B according to its color. The color filter may be formed on a planarization film (not shown). In addition, a resin protective layer (not shown) may be disposed on the color filter. A color filter may be formed on the protective layer 6 . Alternatively, the color filter may be attached after being formed on an opposing substrate such as a glass substrate.

Fig. 1B is a schematic cross-sectional view of an example of a display device having an organic light emitting element and a transistor connected to the organic light emitting element. A transistor is an example of an active device. The transistor may be a thin film transistor (TFT).

The display device 100 of FIG. 1B includes a substrate 11 made of glass or silicon, and an insulating layer 12 on the substrate 11 . An active element 18 such as a TFT is disposed on the insulating layer, and the gate electrode 13 of the active element, the gate insulating film 14 and the semiconductor layer 15 are disposed on the insulating layer. The TFT 18 includes a semiconductor layer 15 , a drain electrode 16 , and a source electrode 17 . An insulating film 19 is provided on the TFT 18 . The anode 21 and the source electrode 17 constituting the organic light emitting device are connected through the contact hole 20 formed in the insulating film.

The method of electrical connection between the electrodes (anode and cathode) included in the organic light emitting element and the electrodes (source electrode and drain electrode) included in the TFT is not limited to the form shown in Fig. 1B. That is, one of the anode or the cathode and one of the source electrode and the drain electrode of the TFT may be electrically connected. In this case, TFT refers to a thin film transistor.

Although the organic compound layer of the display device 100 is illustrated as a single layer in FIG. 1B , the organic compound layer 22 may have a plurality of layers. A first passivation layer 24 and a second passivation layer 25 for reducing deterioration of the organic light emitting diode are formed on the cathode 23 .

In the display device 100 shown in Fig. 1B, a transistor is used as a switching element, but other switching elements may be used instead of this.

Further, the transistor used in the display device 100 shown in Fig. 1B is not limited to a transistor using a single crystal silicon wafer, and may be a thin film transistor having an active layer on the insulating surface of the substrate. Examples of the active layer include layers of non-single crystal silicon such as single crystal silicon, amorphous silicon and microcrystalline silicon, and non-single crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. A thin film transistor is also called a TFT device.

The transistor included in the display device 100 shown in Fig. 1B may be formed in a substrate such as a Si substrate. Here, "formed in a substrate" means manufacturing a transistor by processing the substrate itself, such as a Si substrate. That is, having the transistor in the substrate can be viewed as integrally forming the substrate and the transistor.

In the organic light emitting device of the present embodiment, the light emission luminance is controlled by a TFT which is an example of the switching device, and by providing the organic light emitting device in a plurality of surfaces, it is possible to display an image having each light emission luminance level. The switching element according to this embodiment is not limited to the TFT, and may be a transistor formed of low-temperature polysilicon, or an active matrix driver formed on a substrate such as a Si substrate. The expression “on the substrate” can also be referred to as “in the substrate”. Whether a transistor is formed in the substrate or a TFT is used is selected based on the size of the display portion, and if the size is about 0.5 inches, for example, an organic light emitting device can be formed on a Si substrate.

Fig. 2 is a schematic diagram showing an example of a display device according to the present embodiment. The display device 1000 includes an upper cover 1001 , a lower cover 1009 , a touch panel 1003 between the covers, a display panel 1005 , a frame 1006 , a circuit board 1007 , and a battery 1008 . may have The touch panel 1003 and the display panel 1005 are connected to the flexible printed circuits FPC 1002 and 1004 . A transistor is printed on the circuit board 1007 . If the display device is not a portable device, the battery 1008 may be omitted, and even if the display device is a portable device, it may be installed in another location.

The display device of this embodiment may have a color filter which has red, green, and blue. The color filters may be arranged in a red, green and blue delta arrangement.

The display apparatus of this embodiment may be used for the display part of a portable terminal. At this time, the display device may have both a display function and an operation function. Examples of the mobile terminal include a mobile phone such as a smart phone, a tablet, and a head mounted display.

The display device of the present embodiment may be used for a display section of an imaging device having an optical section having a plurality of lenses and an imaging element that receives light passing through the optical section. The imaging device may have a display unit that displays information acquired by the imaging device. Further, the display portion may be exposed outside of the imaging device or disposed in the viewfinder. The imaging device may be a digital camera or a digital camcorder. The imaging device may also be referred to as a photoelectric conversion device.

Fig. 3A is a schematic diagram showing an example of the imaging device according to the present embodiment. The imaging device 1100 may include a viewfinder 1101 , a rear display 1102 , an operation unit 1103 , and a casing 1104 . The viewfinder 1101 may include the display device according to the present embodiment. In this case, the display device may display not only the captured image but also environmental information, shooting instruction, and the like. The environmental information may include the intensity and direction of external light, the speed at which the subject moves, and the possibility that the subject is blocked by the shield.

Since the suitable timing for shooting is very short, it is good to display the information as soon as possible. Accordingly, a display device using the organic light emitting device of the present invention can be used. This is because the organic light emitting device has a fast response speed. Compared to a liquid crystal display device, a display device using an organic light emitting element can be suitably used in these devices requiring display speed.

The imaging device 1100 has an optical unit (not shown). The optical section has a plurality of lenses for imaging an image pickup device housed in the casing 1104 . A plurality of lenses can adjust their focus by adjusting their relative positions. This operation can also be performed automatically.

3B is a schematic diagram showing an example of an electronic device according to the present embodiment. The electronic device 1200 includes a display unit 1201 , an operation unit 1202 , and a casing 1203 . The casing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit may be a biometric recognition unit that unlocks the lock by recognizing a fingerprint. An electronic device having a communication unit may be referred to as a communication device. An electronic device may further have a camera function by providing a lens and an imaging element. An image captured by the camera function is displayed on the display unit. Examples of electronic devices include smart phones and laptop computers.

4A and 4B are schematic diagrams showing an example of the display device according to the present embodiment. Fig. 4A is a display device such as a television monitor and a PC monitor. The display device 1300 includes a frame 1301 and a display unit 1302 . The light emitting device of the present embodiment may be used for the display portion 1302 .

The display device 1300 further includes a frame 1301 and a base 1303 supporting the display unit 1302 . The base 1303 is not limited to the shape shown in Fig. 4A. The lower side of the frame 1301 may also serve as a base.

The frame 1301 and the display unit 1302 may be bent. Its curvature radius may be 5000 mm or more and 6000 mm or less.

4B is a schematic diagram showing another example of the display device according to the present embodiment. The display device 1310 shown in FIG. 4B is a foldable and foldable display device. The display device 1310 includes a first display unit 1311 , a second display unit 1312 , a casing 1313 , and a bent point 1314 . Each of the first display portion 1311 and the second display portion 1312 may include the light emitting device of the present embodiment. The first display unit 1311 and the second display unit 1312 may constitute a single seamless display device. The first display unit 1311 and the second display unit 1312 may be separated from each other at the bending point. The first display unit 1311 and the second display unit 1312 may display different images, respectively, or may display one image together.

Fig. 5A is a schematic diagram showing an example of the lighting device according to the present embodiment. The lighting device 1400 may include a casing 1401 , a light source 1402 , a circuit board 1403 , an optical film 1404 , and a light diffusion unit 1405 . The light source may have the organic light emitting element of this embodiment. The optical filter may be a filter that improves the color rendering properties of the light source. The light diffusion unit can effectively diffuse light from a light source, such as a light-up, and transmit the light over a wide range. The optical filter and the light diffuser may be disposed on the light output side of the illumination. If necessary, a cover may be provided as the outermost.

The lighting device is, for example, a device that illuminates a room. The lighting device may emit light having a color such as white, main white, or any color from blue to red. The lighting device may further have a dimming circuit for dimming light. The lighting device may have the organic light emitting element of the present invention and a power supply circuit connected thereto. The power supply circuit is a circuit that converts an AC voltage into a DC voltage. In addition, white has a color temperature of 4200K and main white has a color temperature of 5000K. The lighting device may have a color filter.

The lighting device of this embodiment may have a heat radiation part. The heat sink dissipates heat within the device to the outside, and examples thereof include metals with high specific heat and liquid silicon.

5B is a schematic diagram of a vehicle that is an example of a movable body according to the present embodiment. The vehicle has a tail lamp which is an example of a luminaire. The vehicle 1500 may have a tail lamp 1501, and may be comprised so that a tail lamp may be turned on when a brake operation etc. are performed.

The tail lamp 1501 may include the organic light emitting element of the present embodiment. The tail lamp may have a protective member for protecting the organic EL element. The protective member may be formed of any material that has sufficiently high strength and is transparent, and may be composed of polycarbonate or the like. You may mix polycarbonate with a furandicarboxylic acid derivative, an acrylonitrile derivative, etc.

The vehicle 1500 may include a vehicle body 1503 and a window 1502 installed therein. If the window is not for checking the front and rear of the vehicle, the window may be a transparent display. This transparent display may have the organic light emitting element of this embodiment. In this case, constituent materials, such as an electrode of an organic light emitting element, are comprised by the transparent member.

The moving object of the present embodiment may be a ship, an aircraft, a drone, or the like. The movable body may have a body and a lighting fixture provided in the body. The luminaire may emit light to indicate the position of the body. The lighting fixture has the organic light emitting element of this embodiment.

As described above, by using the device using the organic light emitting element of the present embodiment, stable image display with good image quality over a long period of time becomes possible.

[Example]

Hereinafter, Examples will be described. At this time, the present invention is not limited to these examples.

Synthesis Example 1

Synthesis of compound (16)

Compound (16) was synthesized in the following procedure. First, the synthesis of the ligand will be described.

In a nitrogen atmosphere, 1.36 g of boronic acid, 2.14 g of halide, 0.38 g of tetrakistriphenylphosphine palladium, 15 ml of toluene, 7.5 ml of ethanol, and 15 ml of a 2M aqueous sodium carbonate solution were added to a 100 ml eggplant flask. The temperature was raised from room temperature to 90° C. and stirred for 16 hours and 30 minutes. Toluene and water were added to the resulting product, and magnesium sulfate was added to the extracted organic layer, followed by filtration. After concentration, the resulting product was passed through a column using chloroform. The obtained liquid was concentrated and recrystallized from heptane, and as a result, 2.288 g of the ligand was obtained. The structure ^{was identified by 1} H NMR and GCMS.

Next, the synthesis of the chloro-bridge dimer will be described.

In a nitrogen atmosphere, 1.36 g of iridium chloride, 2.288 g of ligand, 30 ml of 2-ethoxyethanol, and 15 ml of water were added to a 100 ml eggplant flask. The temperature was raised from room temperature to 120° C. and stirred for 20 hours. Water was added to the resulting product, followed by suction filtration. The resulting product was redispersed in ethanol and washed. Toluene was added to the resultant product, the temperature was raised to 100° C., cooled, and filtered to obtain 2.65 g of a product. The structure ^{was identified by 1} H NMR.

In a nitrogen atmosphere, 1.3 g of dimer, 0.45 g of sodium carbonate, 1045 μl of 2,2,6,6-tetramethylheptane-3,5-dione, and 40 ml of 2-ethoxyethanol were added to a 100 ml eggplant flask under a nitrogen atmosphere. The temperature was raised from room temperature to 120° C. and stirred for 13 hours. Water and ethanol were added to the resulting product, followed by suction filtration. The resulting product was dissolved by adding chlorobenzene, followed by celite filtration. The obtained liquid was concentrated and recrystallized from chloroform-methanol, and as a result, 0.73 g of red powder was obtained. The structure ^{was identified by 1} H NMR and MALDI-MASS. In addition, the HNT type was shown in the X-ray structure analysis.

Synthesis Examples 2 to 7

Compounds (31), (56), (22), (91), (92) and (94) were synthesized in the same manner as in Synthesis Example 1.

Composition ratio measurement of the composition

The composition ratio of the composition containing the compound (16) obtained in the synthesis example was measured in the following procedure. In 1 mL of dichloromethane, 1 mg of the red powder obtained in the Synthesis Example was dissolved, and HPLC measurement was performed, and it was found that compound (16) was 98.5% and the isomer was 1.5%.

Conditions for HPLC measurement: ODS-SP 5 μm, 4.6*150 mm was used as a column, and methanol was used as a developing solvent. The flow rate was 1.0 mL/min.

The retention time of compound (16) was 6.1 min, and the retention time of the isomer was 5.6 min. Since the two substances were confirmed to have the same molecular weight by LC-MASS, it was confirmed that they were isomers.

Comparative Example 1

The red powder obtained in Synthesis Example 1 was subjected to ^{sublimation purification at 360° C. and 3×10 −3} Pa to recover the high-temperature powder, which contained 98.9% of compound (16) and 1.1% of the isomer.

An organic light-emitting device having this structure by sequentially forming an anode/hole injection layer/hole transport layer/electron blocking layer/light emitting layer/hole blocking layer/electron transport layer/cathode on a substrate using the composition purified in Comparative Example 1 above. was formed as follows.

On a glass substrate, an ITO film with a thickness of 100 nm was formed as an anode by sputtering, and this glass substrate was used as a transparent conductive support substrate (ITO substrate). On this ITO substrate, the organic compound layer and electrode layer shown below were continuously formed by resistance heating vacuum deposition in a vacuum chamber of ^{1x10 -5 Pa.} At this time, the opposing electrode area was arranged to be ^{3 mm 2 .}

Hole injection layer (10 nm): HT16

Hole transport layer (30 nm): HT3

Electron blocking (EB) layer (10 nm): HT7

Light emitting layer (30 nm) Host material: EM33, Assist material: GD10, Guest material: Composition (4wt%)

Hole blocking (HB) layer (45 nm): ET12

Electron transport layer (20 nm): ET7

Metal electrode layer 1 (0.5 nm): LiF

Metal electrode layer 2 (100 nm): Al

Next, the organic light emitting device was covered with a protective glass plate in a dry air atmosphere and sealed with an acrylic resin adhesive to prevent deterioration of the organic light emitting device due to adsorption of moisture.

^{In the obtained organic light emitting device, a constant current of 20 mA/cm 2} was supplied between the ITO electrode as the anode and the Al electrode as the cathode, and the driving life was measured. (hr) was found to be 140 hours.

Comparative Example 2

The red powder obtained in Synthesis Example 1 was subjected to ^{sublimation purification at 360° C. and 3×10 −3} Pa to recover the low-temperature powder, which contained 96.5% of compound (16) and 3.5% of the isomer.

An organic light emitting element was produced in the same manner as in Comparative Example 1 except that the composition obtained in Comparative Example 2 was used instead of the composition obtained in Comparative Example 1.

^{In the obtained organic light emitting device, a constant current of 20 mA/cm 2} was supplied between the ITO electrode as the anode and the Al electrode as the cathode, and the driving life was measured. As a result, LT95 was found to be 135 hours.

Example 1

The red powder obtained in Synthesis Example 1 was redispersed twice in toluene and washed. After vacuum drying at 150 DEG C ^{, sublimation purification was performed at 360 DEG C and 3 x 10 -3} Pa to recover the high-temperature powder. The powder contained 99.1% of compound (16) and 0.9% of the isomer.

An organic light emitting element was produced in the same manner as in Comparative Example 1 except that the composition obtained in Example 1 was used instead of the composition obtained in Comparative Example 1.

^{In the obtained organic light-emitting device, a constant current of 20 mA/cm 2} was supplied between the ITO electrode as the anode and the Al electrode as the cathode, and the driving life was measured, and it was found that LT95 was 170 hours.

Example 2

The red powder obtained in Synthesis Example 1 was dissolved in chloroform, and purified by a GPC purification apparatus (LC-9104: manufactured by Nippon Analytical Industry Co., Ltd., column: JAIGEL-2H-40×2). After concentration and vacuum drying at 150° C. ^{, sublimation purification was performed at 360° C. and 3×10 −3} Pa, and the high-temperature powder was recovered. As a result of measuring the composition ratio, it was found that the powder contained 99.6% of compound (16) and 0.4% of the isomer.

An organic light-emitting device was produced in the same manner as in Comparative Example 1 except that the composition obtained in Example 2 was used instead of the composition obtained in Comparative Example 1.

^{In the obtained organic light emitting device, a constant current of 20 mA/cm 2} was supplied between the ITO electrode as the anode and the Al electrode as the cathode, and the driving life was measured. As a result, LT95 was found to be 200 hours.

Example 3

An organic light-emitting device was produced in the same manner as in Example 1 except that the composition containing the compound (31) obtained in Synthesis Example 2 was used instead of the composition obtained in Synthesis Example 1.

^{In the obtained organic light-emitting device, a constant current of 20 mA/cm 2} was supplied between the ITO electrode as the anode and the Al electrode as the cathode, and the driving life was measured. As a result, LT95 was found to be 335 hours.

Example 4

An organic light-emitting device was manufactured in the same manner as in Example 1 except that the composition containing the compound (56) obtained in Synthesis Example 3 was used instead of the composition obtained in Synthesis Example 1.

^{In the obtained organic light-emitting device, a constant current of 20 mA/cm 2} was supplied between the ITO electrode as the anode and the Al electrode as the cathode, and the driving life was measured, and it was found that LT95 was 500 hours.

Example 5

An organic light emitting device was manufactured in the same manner as in Example 1 except that the composition containing the compound (22) obtained in Synthesis Example 4 was used instead of the composition obtained in Synthesis Example 1.

In the obtained organic light emitting device, ^{a constant current of 20 mA/cm 2} was supplied between the ITO electrode serving as the anode and the Al electrode serving as the cathode, and the driving life was measured. As a result, LT95 was found to be 210 hours.

Example 6

An organic light-emitting device was manufactured in the same manner as in Example 1 except that the composition containing the compound (91) obtained in Synthesis Example 5 was used instead of the composition obtained in Synthesis Example 1.

^{In the obtained organic light emitting device, a constant current of 20 mA/cm 2} was supplied between the ITO electrode as the anode and the Al electrode as the cathode, and the driving life was measured. As a result, it was found that the LT95 group was 535 hours.

Example 7

An organic light emitting device was manufactured in the same manner as in Example 1 except that the composition containing the compound (92) obtained in Synthesis Example 6 was used instead of the composition obtained in Synthesis Example 1.

^{In the obtained organic light-emitting device, a constant current of 20 mA/cm 2} was supplied between the ITO electrode as the anode and the Al electrode as the cathode, and the driving life was measured. As a result, LT95 was found to be 485 hours.

Example 8

An organic light-emitting device was manufactured in the same manner as in Example 1 except that the composition containing the compound (94) obtained in Synthesis Example 7 was used instead of the composition obtained in Synthesis Example 1.

In the obtained organic light emitting device, ^{a constant current of 20 mA/cm 2} was supplied between the ITO electrode serving as the anode and the Al electrode serving as the cathode, and the driving life was measured. As a result, LT95 was found to be 470 hours.

Table 1 summarizes the results of Examples 1 to 8 and Comparative Examples 1 and 2.

As described above, in the composition according to the present invention, it was found that by adjusting the composition ratio of the isomer of the iridium complex to 1.0% or less, the device lifetime of the organic light emitting device can be improved.

This invention can provide the composition containing the iridium complex in which the quantity of the isomer of an iridium complex was reduced.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the present invention is not limited to these embodiments. The protection scope of the following claims should be construed in the broadest way to cover all modifications, equivalent structures and functions.

Claims (21)

an iridium atom and a first ligand, a second ligand and a third ligand bonded to the iridium atom, wherein the second ligand has the same structure as the first ligand, and the third ligand comprises the first and the first ligands. A homo-N-trans (HNT) iridium complex having a structure different from that of the 2 ligand;
has the iridium atom, a fourth ligand, a fifth ligand, and the third ligand, wherein the fourth ligand is a ligand expressed by the same canonical formula as the first ligand, and the fifth ligand is canonically expressed as the second ligand. A composition comprising an isomer of the iridium complex, which is the ligand represented,
The composition ratio of the isomer to the total of the iridium complex and the isomer is 1.0% or less.
The method of claim 1,
The composition ratio of the isomer is 0.6% or less.
The method of claim 1,
The isomer is a structural isomer of the iridium complex, and a composition satisfying at least one of the following (1) and (2):
(1) the first ligand has a structure different from that of the fourth ligand, and
(2) The second ligand has a structure different from that of the fifth ligand.
4. The method of claim 3,
Each of the first and second ligands has a structure having a substituent, and the fourth or fifth ligand has a structure having a substituent at a different substitution position from the first or second ligand.
4. The method of claim 3,
A composition satisfying both (1) and (2) above.
The method of claim 1,
A composition in which the isomer is a stereoisomer of the iridium complex and satisfies at least one of the following (3) and (4):
(3) the first ligand and the fourth ligand have different steric configurations with respect to the iridium atom, and
(4) The second ligand and the fifth ligand have different steric configurations with respect to the iridium atom.
7. The method of claim 6,
A composition satisfying both (3) and (4) above.
The method of claim 1,
A composition in which the iridium complex is an iridium complex represented by the following general formula [1] or [2]:

In this case, in the general formulas [1] and [2], L represents a bidentate ligand, R ¹ to R ¹⁸ are a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy each independently selected from a group, a cyano group, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted heteroaromatic group,
Ring A may have a substituent and is selected from a benzene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring, a 9,9-spirobifluorene ring, a chrysene ring, and a substituted or unsubstituted heteroaromatic group , represents a cyclic structure,
IrL is represented by one of the following general formulas [3] to [5],

In this case, in the general formulas [3] to [5], R ¹⁹ to R ³³ are selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, and a substituted or unsubstituted heteroaromatic group. Each is independently selected.
The method of claim 1,
The iridium complex is an iridium complex represented by the following general formula [6]:

In this case, in the general formula [6], R ³⁴ to R ⁴⁸ are each independently selected from a hydrogen atom and a substituted or unsubstituted alkyl group, and R ⁴² to R ⁴⁵ may be bonded to each other to form a ring structure.
10. The method of claim 9,
In the iridium complex represented by the general formula [6], R ⁴⁵ represents a hydrogen atom, R ⁴³ represents an alkyl group,
In the isomer of the iridium complex represented by the general formula [6], R ⁴⁵ represents an alkyl group and R ⁴³ represents a hydrogen atom.
10. The method of claim 9,
In the iridium complex represented by the general formula [6], R ³⁷ represents a cyano group.
a first electrode;
a second electrode;
An organic light emitting device having an organic compound layer disposed between the first electrode and the second electrode,
The organic compound layer is an organic light emitting device comprising the composition according to claim 1.
13. The method of claim 12,
The organic compound layer is a light emitting layer, the light emitting layer further comprises a first organic compound,
The first organic compound is an organic light emitting device, wherein the lowest triplet excitation energy is higher than that of the iridium complex included in the composition.
14. The method of claim 13,
The light emitting layer further comprises a second organic compound,
The second organic compound is an organic light emitting device having a lowest triplet excitation energy that is equal to or higher than the lowest triplet excitation energy of the iridium complex included in the composition and is equal to or lower than the lowest triplet excitation energy of the first organic compound.
14. The method of claim 13,
The organic compound layer includes a first charge transport layer disposed between the first electrode and the light emitting layer, and a second charge transport layer disposed between the second electrode and the light emitting layer,
The first electrode contacts the first charge transport layer, and the second electrode contacts the second charge transport layer.
A plurality of pixels, at least one of which is the organic light emitting device according to any one of claims 12 to 15;
A display device having a transistor connected to the organic light emitting element.
17. The method of claim 16,
A display device further comprising a color filter on a light emission side of the organic light emitting diode.
An optical unit having a plurality of lenses;
an imaging device that receives the light passing through the optical unit;
and a display unit for displaying an image captured by the imaging device;
The image pickup device including the organic light emitting element according to any one of claims 12 to 15, wherein the display unit.
A display unit including the organic light emitting device according to any one of claims 12 to 15;
a casing in which the display unit is disposed;
An electronic device disposed inside the casing and having a communication unit communicating with the outside.
A light source having the organic light emitting element according to any one of claims 12 to 15;
A lighting device having a light diffusion unit or an optical film that transmits light generated from the light source.
A luminaire having the organic light emitting element according to any one of claims 12 to 15;
A movable body having a body in which the luminaire is disposed.

Images