KR20210089596A - Organic light emitting device - Google Patents

Abstract

The present invention provides an organic light emitting element having increased driving voltage, efficiency, and lifetime. The organic light emitting element comprises: an anode; a cathode; and an organic layer having at least one layer installed between the anode and the cathode.

Description

Organic light emitting device

The present invention relates to an organic light emitting device having improved driving voltage, efficiency, and lifetime.

In general, the organic light emitting phenomenon refers to a phenomenon in which electric energy is converted into light energy using an organic material. The organic light emitting device using the organic light emitting phenomenon has a wide viewing angle, excellent contrast, fast response time, and excellent luminance, driving voltage, and response speed characteristics, and thus many studies are being conducted.

An organic light emitting device generally has a structure including an anode and a cathode and an organic material layer between the anode and the cathode. The organic layer is often formed of a multi-layered structure composed of different materials in order to increase the efficiency and stability of the organic light-emitting device, and may include, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like. In the structure of the organic light emitting device, when a voltage is applied between the two electrodes, holes are injected into the organic material layer from the anode and electrons from the cathode are injected into the organic material layer. When the injected holes and electrons meet, excitons are formed, and the excitons When it falls back to the ground state, it lights up.

In the organic light emitting device as described above, the development of an organic light emitting device having improved driving voltage, efficiency, and lifespan is continuously required.

Korean Patent Publication No. 10-2000-0051826

The present invention relates to an organic light emitting device having improved driving voltage, efficiency, and lifetime.

The present invention provides the following organic light emitting device:

anode,

cathode,

An organic light emitting device comprising one or more organic material layers provided between the anode and the cathode,

The organic material layer includes a light emitting layer,

The light emitting layer comprises a compound represented by the following formula (1) and a compound represented by the following formula (2),

Organic light emitting device:

[Formula 1]

In Formula 1,

Ar ₁ and Ar ₂ are each independently phenyl, biphenylyl, or naphthyl; wherein Ar ₁ and Ar ₂ are each independently, unsubstituted or substituted with one or more naphthyl,

L is a single bond, phenylene, or naphthylene,

[Formula 2]

In Formula 2,

Ar ₃ is phenyl, biphenylyl. terphenylyl, naphthyl, dibenzofuranyl, or dibenzothiophenyl;

L ₁ is a single bond or phenylene; wherein L ₁ is unsubstituted or substituted with one or more phenyl,

any one of a ₁ is combined with Formula 3 below; _{a 1} not bonded to Formula 3 is each independently hydrogen or deuterium,

m is an integer from 1 to 5,

[Formula 3]

In Formula 3,

Ar ₄ is phenyl, biphenylyl. terphenylyl, naphthyl, dibenzofuranyl, or dibenzothiophenyl;

L ₂ is a single bond or phenylene; wherein L ₁ is unsubstituted or substituted with one or more phenyl,

any one of a ₂ is combined with Formula 2 above; _{a 2} not bonded to Formula 2 is each independently hydrogen or deuterium,

n is an integer from 1 to 5;

The organic light emitting device described above has excellent driving voltage, efficiency, and lifetime.

FIG. 1 shows an example of an organic light emitting device including an anode 1 , a light emitting layer 2 , and a cathode 3 .
2 is an organic light emitting device comprising an anode 1, a hole injection layer 4, a hole transport layer 5, a light emitting layer 2, a hole blocking layer 6, an electron transport layer 7, and a cathode 3 is shown as an example of

Hereinafter, it will be described in more detail to help the understanding of the present invention.

또는

는 다른 치환기에 연결되는 결합을 의미한다. In this specification,

or

means a bond connected to another substituent.

As used herein, the term "substituted or unsubstituted" refers to deuterium; halogen group; nitrile group; nitro group; hydroxyl group; carbonyl group; ester group; imid; amino group; phosphine oxide group; alkoxy group; aryloxy group; alkyl thiooxy group; arylthioxy group; an alkyl sulfoxy group; arylsulfoxy group; silyl group; boron group; an alkyl group; cycloalkyl group; alkenyl group; aryl group; aralkyl group; aralkenyl group; an alkylaryl group; an alkylamine group; an aralkylamine group; heteroarylamine group; arylamine group; an arylphosphine group; or N, O, and S atom means that it is substituted or unsubstituted with one or more substituents selected from the group consisting of a heterocyclic group containing one or more atoms, or substituted or unsubstituted with two or more substituents connected among the above-exemplified substituents . For example, "a substituent in which two or more substituents are connected" may be a biphenyl group. That is, the biphenyl group may be an aryl group, and may be interpreted as a substituent in which two phenyl groups are connected.

In the present specification, the number of carbon atoms in the carbonyl group is not particularly limited, but preferably 1 to 40 carbon atoms. Specifically, it may be a compound having the following structure, but is not limited thereto.

In the present specification, in the ester group, the oxygen of the ester group may be substituted with a linear, branched or cyclic alkyl group having 1 to 25 carbon atoms or an aryl group having 6 to 25 carbon atoms. Specifically, it may be a compound of the following structural formula, but is not limited thereto.

In the present specification, the number of carbon atoms of the imide group is not particularly limited, but it is preferably from 1 to 25 carbon atoms. Specifically, it may be a compound having the following structure, but is not limited thereto.

In the present specification, the silyl group specifically includes a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, a propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, a phenylsilyl group, and the like. However, the present invention is not limited thereto.

In the present specification, the boron group specifically includes, but is not limited to, a trimethylboron group, a triethylboron group, a t-butyldimethylboron group, a triphenylboron group, a phenylboron group, and the like.

In the present specification, examples of the halogen group include fluorine, chlorine, bromine or iodine.

In the present specification, the alkyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 40. According to an exemplary embodiment, the number of carbon atoms in the alkyl group is 1 to 20. According to another exemplary embodiment, the alkyl group has 1 to 10 carbon atoms. According to another exemplary embodiment, the alkyl group has 1 to 6 carbon atoms. Specific examples of the alkyl group include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n -pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl , n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2 -Dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl and the like, but are not limited thereto.

In the present specification, the alkenyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 2 to 40. According to an exemplary embodiment, the carbon number of the alkenyl group is 2 to 20. According to another exemplary embodiment, the carbon number of the alkenyl group is 2 to 10. According to another exemplary embodiment, the alkenyl group has 2 to 6 carbon atoms. Specific examples include vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1- Butenyl, 1,3-butadienyl, aryl, 1-phenylvinyl-1-yl, 2-phenylvinyl-1-yl, 2,2-diphenylvinyl-1-yl, 2-phenyl-2-( Naphthyl-1-yl)vinyl-1-yl, 2,2-bis(diphenyl-1-yl)vinyl-1-yl, stilbenyl group, styrenyl group, and the like, but are not limited thereto.

In the present specification, the cycloalkyl group is not particularly limited, but preferably has 3 to 60 carbon atoms, and according to an exemplary embodiment, the cycloalkyl group has 3 to 30 carbon atoms. According to another exemplary embodiment, the carbon number of the cycloalkyl group is 3 to 20. According to another exemplary embodiment, the cycloalkyl group has 3 to 6 carbon atoms. Specifically, cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3, 4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, and the like, but is not limited thereto.

In the present specification, the aryl group is not particularly limited, but preferably has 6 to 60 carbon atoms, and may be a monocyclic aryl group or a polycyclic aryl group. According to an exemplary embodiment, the carbon number of the aryl group is 6 to 30. According to an exemplary embodiment, the carbon number of the aryl group is 6 to 20. The aryl group may be a monocyclic aryl group such as a phenyl group, a biphenyl group, or a terphenyl group, but is not limited thereto. The polycyclic aryl group may be a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, a perylenyl group, a chrysenyl group, a fluorenyl group, and the like, but is not limited thereto.

등이 될 수 있다. 다만, 이에 한정되는 것은 아니다.In the present specification, the fluorenyl group may be substituted, and two substituents may be bonded to each other to form a spiro structure. When the fluorenyl group is substituted,

etc. can be However, the present invention is not limited thereto.

In the present specification, the heterocyclic group is a heterocyclic group including at least one of O, N, Si and S as a heterogeneous element, and the number of carbon atoms is not particularly limited, but it is preferably from 2 to 60 carbon atoms. Examples of the heterocyclic group include a thiophene group, a furan group, a pyrrole group, an imidazole group, a thiazole group, an oxazole group, an oxadiazole group, a triazole group, a pyridyl group, a bipyridyl group, a pyrimidyl group, a triazine group, a triazole group, Acridyl group, pyridazine group, pyrazinyl group, quinolinyl group, quinazoline group, quinoxalinyl group, phthalazinyl group, pyrido pyrimidinyl group, pyrido pyrazinyl group, pyrazino pyrazinyl group, isoquinoline group , indole group, carbazole group, benzooxazole group, benzoimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group, dibenzothiophene group, benzofuranyl group, phenanthroline group, thiazolyl group, an isoxazolyl group, an oxadiazolyl group, a thiadiazolyl group, a benzothiazolyl group, a phenothiazinyl group, and a dibenzofuranyl group, but are not limited thereto.

In the present specification, the aryl group in the aralkyl group, the aralkenyl group, the alkylaryl group, and the arylamine group is the same as the above-described aryl group. In the present specification, the alkyl group among the aralkyl group, the alkylaryl group, and the alkylamine group is the same as the example of the above-described alkyl group. In the present specification, as for heteroaryl among heteroarylamines, the description of the above-described heterocyclic group may be applied. In the present specification, the alkenyl group among the aralkenyl groups is the same as the above-described examples of the alkenyl group. In the present specification, the description of the above-described aryl group may be applied except that arylene is a divalent group. In the present specification, the description of the above-described heterocyclic group may be applied, except that heteroarylene is a divalent group. In the present specification, the hydrocarbon ring is not a monovalent group, and the description of the above-described aryl group or cycloalkyl group may be applied, except that it is formed by combining two substituents. In the present specification, the heterocyclic group is not a monovalent group, and the description of the above-described heterocyclic group may be applied, except that it is formed by combining two substituents.

Hereinafter, the present invention will be described in detail for each configuration.

positive and negative

The anode and cathode used in the present invention mean electrodes used in an organic light emitting device.

As the anode material, a material having a large work function is generally preferred so that holes can be smoothly injected into the organic material layer. Specific examples of the anode material include metals such as vanadium, chromium, copper, zinc, gold, or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); combinations of metals and oxides such as ZnO:Al or SNO _{2 :Sb;} conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene](PEDOT), polypyrrole, and polyaniline, but are not limited thereto.

The cathode material is preferably a material having a small work function to facilitate electron injection into the organic material layer. Specific examples of the anode material include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin and lead, or alloys thereof; and a multilayer structure material such as LiF/Al or LiO ₂ /Al, but is not limited thereto.

light emitting layer

The light emitting layer used in the present invention refers to a layer capable of emitting light in the visible ray region by combining holes and electrons transferred from the anode and the cathode. In general, the light emitting layer includes a host material and a dopant material.

The host material may further include a condensed aromatic ring derivative or a hetero ring-containing compound. In the present invention, as the host material, the compound represented by Formula 1 and the compound represented by Formula 2 are mixed and used.

Specifically, Chemical Formula 1 is an N-type Red Host based on a structure in which 1,3,5-triazine (core) and phenanthrene are bonded, and in Chemical Formula 2, aryl or heteroaryl is bonded to each N It is a P-type Red Host based on the biscarbazole structure.

In an organic light emitting device using the two types of compounds as a host material for the light emitting layer, as well as when a compound structurally different from the above two types is used as a host material, only one compound of the two types of compounds serves as a host for the light emitting layer When used as a material, the driving voltage is improved (low voltage), and characteristics of high efficiency and long life can be expressed in preparation for mixing and applying the two types of compounds to the organic layer except for the light emitting layer.

Preferably, the formula 1 is represented by any one of the following formulas 1-1 to 1-5:

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 1-4]

[Formula 1-5]

In Formulas 1-1 to 1-5, _{each definition of Ar 1} , Ar ₂ , and L is the same as described above.

Preferably, Ar ₁ and Ar ₂ are each independently phenyl. biphenylyl, or naphthyl; Ar ₁ and Ar ₂ are each independently, unsubstituted or substituted with one naphthyl.

Representative examples of the compound represented by Formula 1 are as follows:

.

.

The compound represented by Chemical Formula 1 may be prepared by a preparation method as shown in Scheme 1 below.

[Scheme 1]

In Scheme 1, the definition of each substituent is as described above. However, the manufacturing method may be more specific in Preparation Examples to be described later.

On the other hand, preferably, in Formula 2, L ₁ is a single bond, or phenylene; L ₁ is unsubstituted or substituted with one phenyl.

Preferably, L ₂ is a single bond, or phenylene; L ₁ is unsubstituted or substituted with one phenyl.

_{Preferably, a 1} not bound to Formula 3 is all hydrogen.

_{Preferably, a 2} not bonded to Formula 2 is all hydrogen.

Preferably, the formula (2) is represented by the following formula (2-1):

[Formula 2-1]

In Formula 2-1, Ar ₃ , Ar ₄ , L ₁ , L ₂ , and each definition of m and n is the same as described above.

Preferably, m and n are each independently 1 or 2.

Representative examples of the compound represented by Formula 2 are as follows:

.

.

The compound represented by Chemical Formula 2 may be prepared by a preparation method as shown in Scheme 2 below.

[Scheme 2]

In Scheme 2, the definition of each substituent is as described above. However, the manufacturing method may be more specific in Preparation Examples to be described later.

Meanwhile, the dopant material is not particularly limited as long as it is a material used in an organic light emitting device. Examples include an aromatic amine derivative, a strylamine compound, a boron complex, a fluoranthene compound, and a metal complex. Specifically, the aromatic amine derivative is a condensed aromatic ring derivative having a substituted or unsubstituted arylamino group, and includes pyrene, anthracene, chrysene, and periflanthene having an arylamino group, and the styrylamine compound is a substituted or unsubstituted derivative. It is a compound in which at least one arylvinyl group is substituted in the arylamine, and one or two or more substituents selected from the group consisting of an aryl group, a silyl group, an alkyl group, a cycloalkyl group and an arylamino group are substituted or unsubstituted. Specifically, there are styrylamine, styryldiamine, styryltriamine, styryltetraamine, and the like, but is not limited thereto. In addition, the metal complex includes an iridium complex, a platinum complex, and the like, but is not limited thereto.

hole transport layer

The organic light emitting diode according to the present invention may include a hole transport layer between the electron blocking layer and the anode.

The hole transport layer is a layer that receives holes from the hole injection layer and transports the holes to the light emitting layer. As a hole transport material, a material capable of transporting holes from the anode or hole injection layer to the light emitting layer and transferring them to the light emitting layer. This is suitable.

An arylamine-based organic material, a conductive polymer, and a block copolymer having a conjugated portion and a non-conjugated portion may be used as the hole transport material, but the present invention is not limited thereto.

electron suppression layer

The organic light emitting device according to the present invention includes an electron suppressing layer between the anode and the light emitting layer. Preferably, the electron blocking layer is included in contact with the anode side of the light emitting layer.

The electron suppression layer serves to improve the efficiency of the organic light emitting device by suppressing electrons injected from the cathode from being transferred to the anode without recombination in the light emitting layer.

The electron-blocking layer includes an electron-blocking material, and an arylamine-based organic material may be used as an example of the electron-blocking material, but is not limited thereto.

hole injection layer

The organic light emitting diode according to the present invention may further include a hole injection layer between the anode and the hole transport layer, if necessary.

The hole injection layer is a layer for injecting holes from the electrode, and as a hole injection material, it has the ability to transport holes, so it has a hole injection effect at the anode, an excellent hole injection effect with respect to the light emitting layer or the light emitting material, and is produced in the light emitting layer A compound which prevents the movement of excitons to the electron injection layer or the electron injection material and is excellent in the ability to form a thin film is preferable. In addition, it is preferable that the highest occupied molecular orbital (HOMO) of the hole injection material is between the work function of the positive electrode material and the HOMO of the surrounding organic material layer.

Specific examples of the hole injection material include metal porphyrin, oligothiophene, arylamine-based organic material, hexanitrile hexaazatriphenylene-based organic material, quinacridone-based organic material, and perylene-based organic material. of organic substances, anthraquinones, polyaniline and polythiophene-based conductive polymers, and the like, but are not limited thereto.

hole blocking layer

The organic light emitting diode according to the present invention includes a hole blocking layer between the light emitting layer and the electron transport layer, if necessary. Preferably, the hole blocking layer is in contact with the light emitting layer.

The hole blocking layer serves to improve the efficiency of the organic light emitting device by suppressing the transfer of holes injected from the anode to the cathode without recombination in the light emitting layer. Specific examples of the material that can be used as the material of the hole blocking layer include, but are not limited to, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, BCP, and aluminum complexes.

electron transport layer

The organic light emitting device according to the present invention may include an electron transport layer between the light emitting layer and the cathode.

The electron transport layer is a layer that receives electrons from the electron injection layer formed on the cathode or the cathode, transports electrons to the light emitting layer, and suppresses the transfer of holes in the light emitting layer. As an electron transport material, electrons are well injected from the cathode As a material that can receive and transfer to the light emitting layer, a material with high electron mobility is suitable.

Specific examples of the electron transport material include an Al complex of 8-hydroxyquinoline; complexes containing Alq _{3 ;} organic radical compounds; hydroxyflavone-metal complexes, and the like, but are not limited thereto. The electron transport layer may be used with any desired cathode material as used in accordance with the prior art. In particular, examples of suitable cathode materials are conventional materials having a low work function and followed by a layer of aluminum or silver. Specifically cesium, barium, calcium, ytterbium and samarium, followed in each case by an aluminum layer or a silver layer.

electron injection layer

The organic light emitting diode according to the present invention may further include an electron injection layer between the electron transport layer and the cathode, if necessary.

The electron injection layer is a layer that injects electrons from the electrode, has the ability to transport electrons, has an electron injection effect from the cathode, an excellent electron injection effect on the light emitting layer or the light emitting material, and hole injection of excitons generated in the light emitting layer It is preferable to use a compound which prevents migration to a layer and is excellent in the ability to form a thin film.

Specific examples of the material that can be used as the electron injection layer include fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, preole nylidene methane, anthrone, and the like, derivatives thereof, metal complex compounds, nitrogen-containing 5-membered ring derivatives, and the like, but are not limited thereto.

Examples of the metal complex compound include 8-hydroxyquinolinato lithium, bis(8-hydroxyquinolinato)zinc, bis(8-hydroxyquinolinato)copper, bis(8-hydroxyquinolinato)manganese, Tris(8-hydroxyquinolinato)aluminum, tris(2-methyl-8-hydroxyquinolinato)aluminum, tris(8-hydroxyquinolinato)gallium, bis(10-hydroxybenzo[h] Quinolinato) beryllium, bis (10-hydroxybenzo [h] quinolinato) zinc, bis (2-methyl-8-quinolinato) chlorogallium, bis (2-methyl-8-quinolinato) ( o-crezolato)gallium, bis(2-methyl-8-quinolinato)(1-naphtolato)aluminum, bis(2-methyl-8-quinolinato)(2-naphtolato)gallium, etc. However, the present invention is not limited thereto.

organic light emitting device

The structure of the organic light emitting device according to the present invention is illustrated in FIG. 1 . FIG. 1 shows an example of an organic light emitting device including an anode 1 , a light emitting layer 2 , and a cathode 3 . In addition, the structure of the organic light emitting device in the case of further including the hole injection layer 4, the hole transport layer 5, the hole blocking layer 6, and the electron transport layer 7 is illustrated in FIG.

The organic light emitting device according to the present invention may be manufactured by sequentially stacking the above-described components. At this time, by using a PVD (physical vapor deposition) method such as sputtering or e-beam evaporation, a metal or conductive metal oxide or an alloy thereof is deposited on a substrate to form an anode. And, after forming each of the above-mentioned layers thereon, it can be prepared by depositing a material that can be used as a cathode thereon. In addition to this method, an organic light emitting device may be manufactured by sequentially depositing the anode material on the substrate in the reverse order from the cathode material to the anode material (WO 2003/012890). In addition, the light emitting layer may be formed by a solution coating method as well as a vacuum deposition method for the host and the dopant. Here, the solution application method refers to spin coating, dip coating, doctor blading, inkjet printing, screen printing, spray method, roll coating, and the like, but is not limited thereto.

On the other hand, the organic light emitting device according to the present invention may be a top emission type, a back emission type, or a double-sided emission type depending on the material used.

Hereinafter, preferred examples are presented to help the understanding of the present invention. However, the following examples are only provided for easier understanding of the present invention, and the content of the present invention is not limited thereto.

[Production Example]

Preparation 1-1: Preparation of compound 1-1

Step 1) Preparation of Compound A-1

Phenanthrene-9-yl boronic acid (50 g, 225.1 mmol), 1-broro-4-chloronaphthalene (1 eq) , Pd(P(t-Bu) ₃ ) ₂ (0.005 eq) and potassium carbonate (3 eq) was dissolved in a mixed solution of THF (500 ml) and distilled water (250 ml) and refluxed for 1 hour. After the reaction was completed, distilled water was removed, and the organic layer was extracted and dried over magnesium sulfate. After distillation under reduced pressure, it was purified by column chromatography using silica to obtain Compound A-1 (52.5 g, yield: 69%).

MS: [M+H] ⁺ =338

Step 2) Preparation of compound A-2

Compound A-2 (52.5g, 155.3mmol), pinacolatodiboron (1.1eq), Pd(dppf)Cl ₂ (0.02 eq) and potassium carbonate (3 eq) were dissolved in 500ml of 1,4-dioxane for 3 hours refluxed. After the reaction was completed, distilled water was added, and the organic layer was extracted and dried over magnesium sulfate. Purification was performed using column chromatography to obtain compound A-2 (48.1 g, yield: 72%).

MS: [M+H] ⁺ =430

Step 3) Preparation of compound 1-1

Compound A-2 (48 g, 111.8 mmol), 2-chloro-4- (naphthalen-2-yl) -6-phenyl-1,3,5-triazine (leq), Pd (P (t-Bu) ₃ ) ₂ (0.005 eq) and potassium carbonate (3 eq) were dissolved in a mixed solution of THF (400 ml) and distilled water (200 ml) and refluxed for 1 hour. After the reaction was completed, distilled water was removed, and the organic layer was extracted and dried over magnesium sulfate. After distillation under reduced pressure, it was purified by column chromatography using silica to obtain compound 1 (42.8 g, yield: 62%).

MS: [M+H] ⁺ =585

Preparation 1-2: Preparation of compound 1-2

In step 1 of Preparation Example 1, Compound 2 was prepared in the same manner as in Example 1, except that phenanthren-1-yl boronic acid was used instead of phenanthren-9-yl boronic acid.

Preparation Example 1-3: Preparation of compound 1-3

In Step 1 of Preparation Example 1, Compound 2 was prepared in the same manner as in Example 1, except that phenanthrene-4-ylboronic acid was used instead of phenanthrene-9-ylboronic acid.

Preparation Example 2: Preparation of compound 2

(9-([1,1'-biphenyl]-4-yl)-9-H-carbazol-3-yl)boronic acid (50g, 137.7mmol), 3-bromer-9phenyl-9- H-carbazole (1eq), Pd(P(t-Bu) ₃ ) ₂ (0.005 eq) and potassium carbonate (3 eq) were dissolved in a mixed solution of THF (500 ml) and distilled water (250 ml) and refluxed for 1 hour. did it After the reaction was completed, distilled water was removed, and the organic layer was extracted and dried over magnesium sulfate. After distillation under reduced pressure, it was purified by column chromatography using silica to obtain compound 2 (44.7 g, yield: 58%).

MS: [M+H] ⁺ =560

[Example]

Example 1

A glass substrate coated with indium tin oxide (ITO) to a thickness of 1,300 Å was placed in distilled water in which detergent was dissolved and washed with ultrasonic waves. In this case, a product manufactured by Fischer Co. was used as the detergent, and distilled water that was secondarily filtered with a filter manufactured by Millipore Co. was used as the distilled water. After washing ITO for 30 minutes, ultrasonic cleaning was performed for 10 minutes by repeating twice with distilled water. After washing with distilled water, ultrasonic washing was performed with a solvent of isopropyl alcohol, acetone, and methanol, dried, and then transported to a plasma cleaner. In addition, after cleaning the substrate for 5 minutes using oxygen plasma, the substrate was transported to a vacuum evaporator.

A hole injection layer was formed by thermal vacuum deposition of the following HAT-CN compound to a thickness of 500 Å on the ITO transparent electrode prepared as described above. The following HT1 compound was thermally vacuum-deposited to a thickness of 800 Å on the hole injection layer, and the following HT2 compound was sequentially vacuum-deposited to a thickness of 500 Å to form a hole transport layer. On the hole transport layer, the compound 1 and the compound 2 as a host, and the following Dp-7 compound as a dopant (a dopant is used in an amount of 3 wt% with respect to the total amount of the host and dopant) is vacuum deposited to a thickness of 300 Å A light emitting layer was formed. The following ET-1 compound was vacuum-deposited to a thickness of 50 Å on the light emitting layer to form a hole blocking layer, and the following ET-2 compound and LiQ (Lithium Quinolate) were added to the hole blocking layer in a weight ratio of 1:1 250 An electron transport layer was formed by vacuum deposition to a thickness of Å. Lithium fluoride (LiF) having a thickness of 10 Å was sequentially deposited on the electron transport layer, and aluminum was deposited thereon to a thickness of 1000 Å to form a cathode.

In the above process, the deposition rate of the organic material was maintained at 0.4 to 0.7 Å/sec, the deposition rate of lithium fluoride of the negative electrode was maintained at 0.3 Å/sec, and the deposition rate of aluminum was maintained at 2 Å/sec. ^-7 ~ 5×10 ^-8 torr was maintained

Examples 2 and 3

An organic light emitting diode was manufactured in the same manner as in Example 1, except that the compound shown in Table 1 was used instead of Compound 1.

Comparative Examples 1 and 2

An organic light emitting diode was manufactured in the same manner as in Example 1, except that the compound shown in Table 1 was used instead of Compound 1.

In Table 1 below, compounds CE1 and CE2 are as follows, respectively.

Experimental example

^{When a current of 10 mA/cm 2} was applied to the organic light-emitting devices prepared in Examples and Comparative Examples, the driving voltage, luminous efficiency, lifetime, and luminous color were measured, and the results are shown in Table 1 below. The driving voltage, luminous efficiency, and luminous color are data at 5000 nit luminance, and the lifetime T98 means the time required to decrease from the initial luminance (5000 nit) to 98%.

division matter drive voltage
(V) efficiency
(cd/A) life span
T98(hr) luminous color Example 1 compound 1-1 compound 2 4.1 35.3 51 Red Example 2 compound 1-2 compound 2 3.9 36.8 40 Red Example 3 compound 1-3 compound 2 4.1 37.0 47 Red Comparative Example 1 compound CE1 4.4 24.6 17 Red Comparative Example 2 compound CE2 4.7 28.1 28 Red

As shown in Table 1, the organic light emitting device to which the compound combination according to the present invention is applied has improved luminous efficiency while lowering the driving voltage, and all of them exhibited red light emission. In addition, it showed an improvement effect of up to 50% in terms of efficiency compared to the comparative materials CE1 and CE2, and there was an overall advantage of the driving voltage. On the other hand, Comparative Example 1 had a relatively low driving voltage but a very short lifespan, and Comparative Example 2 had a high driving voltage and a short lifespan.

From the above results, it can be confirmed that the compound combination according to the present invention can be used as a light emitting layer material in an organic light emitting device to exhibit high efficiency, low driving voltage, and long lifespan.

1: anode 2: light emitting layer
3: cathode 4: hole injection layer
5: hole transport layer 6: hole suppression layer
7: electron transport layer

Claims (11)

anode,
cathode,
An organic light emitting device comprising one or more organic material layers provided between the anode and the cathode,
The organic material layer includes a light emitting layer,
The light emitting layer comprises a compound represented by the following formula (1) and a compound represented by the following formula (2),
Organic light emitting device:
[Formula 1]

In Formula 1,
Ar ₁ and Ar ₂ are each independently phenyl, biphenylyl, or naphthyl; wherein Ar ₁ and Ar ₂ are each independently, unsubstituted or substituted with one or more naphthyl,
L is a single bond, phenylene, or naphthylene,
[Formula 2]

In Formula 2,
Ar ₃ is phenyl, biphenylyl. terphenylyl, naphthyl, dibenzofuranyl, or dibenzothiophenyl;
L ₁ is a single bond or phenylene; wherein L ₁ is unsubstituted or substituted with one or more phenyl,
any one of a ₁ is combined with Formula 3 below; _{a 1} not bonded to Formula 3 is each independently hydrogen or deuterium,
m is an integer from 1 to 5,
[Formula 3]

In Formula 3,
Ar ₄ is phenyl, biphenylyl. terphenylyl, naphthyl, dibenzofuranyl, or dibenzothiophenyl;
L ₂ is a single bond or phenylene; wherein L ₁ is unsubstituted or substituted with one or more phenyl,
any one of a ₂ is combined with Formula 2 above; _{a 2} not bonded to Formula 2 is each independently hydrogen or deuterium,
n is an integer from 1 to 5;
According to claim 1,
Formula 1 is represented by any one of the following Formulas 1-1 to 1-5,
Organic light emitting device:
[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

[Formula 1-4]

[Formula 1-5]

In Formulas 1-1 to 1-5, _{each definition of Ar 1} , Ar ₂ , and L is the same as in claim 1.
According to claim 1,
Ar ₁ and Ar ₂ are each independently, phenyl. biphenylyl, or naphthyl; wherein Ar ₁ and Ar ₂ are each independently, unsubstituted or substituted with one naphthyl,
organic light emitting device.
According to claim 1,
Formula 1 is any one selected from the group consisting of the following compounds,
Organic light emitting device:

.
According to claim 1,
L ₁ is a single bond or phenylene; wherein L ₁ is unsubstituted or substituted with one phenyl,
organic light emitting device.
According to claim 1,
L ₂ is a single bond or phenylene; wherein L ₁ is unsubstituted or substituted with one phenyl,
organic light emitting device.
According to claim 1,
_{a 1} not bonded to Formula 3 is all hydrogen,
organic light emitting device.
According to claim 1,
_{a 2} not bonded to Formula 2 is all hydrogen,
organic light emitting device.
According to claim 1,
The formula 2 is represented by the following formula 2-1,
Organic light emitting device:
[Formula 2-1]

In Formula 2-1, Ar ₃ , Ar ₄ , L ₁ , L ₂ , and each definition of m and n is the same as in claim 1.
According to claim 1,
m and n are each independently 1 or 2;
organic light emitting device.
According to claim 1,
Formula 2 is any one selected from the group consisting of the following compounds, compounds:

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