KR20200131617A - Organic light emitting device - Google Patents

Abstract

The present invention provides an organic light emitting element with the improved driving voltage, efficiency, and lifetime. The organic light emitting element includes a substrate (1), a positive electrode (2), a hole transport layer (3), a light-emitting layer (4), and a negative electrode (5).

Description

Organic light emitting device TECHNICAL FIELD

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

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

The 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 material layer is often made of a multi-layered structure composed of different materials in order to increase the efficiency and stability of the organic light emitting device.For example, it may be formed of 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 such an organic light-emitting device, when a voltage is applied between the two electrodes, holes are injected from the anode and electrons from the cathode are injected into the organic material layer, and excitons are formed when the injected holes and electrons meet. It glows when it falls back to the ground.

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

Korean Patent Publication No. 10-2000-0051826 Korean Patent Registration No. 10-1788094 Korean Patent Publication No. 10-2012-0129733

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,

Comprising a light emitting layer between the anode and the cathode,

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 element:

[Formula 1]

In Formula 1,

Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted C _6-60 aryl,

R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen; heavy hydrogen; halogen; Cyano; Nitro; Amino; Substituted or unsubstituted C _1-60 alkyl; Substituted or unsubstituted C _3-60 cycloalkyl; Substituted or unsubstituted C _2-60 alkenyl; Substituted or unsubstituted C _6-60 aryl; Or substituted or unsubstituted C _2-60 heteroaryl including any one or more selected from the group consisting of N, O and S,

a1 is an integer from 0 to 7,

a2 is an integer from 0 to 3,

a3 is an integer from 0 to 2,

[Formula 2]

In Chemical Formula 2,

Ar ₃ and Ar ₄ are each independently a substituted or unsubstituted C _6-60 aryl; Or substituted or unsubstituted C _2-60 heteroaryl including any one or more selected from the group consisting of N, O and S,

R ₅ and R ₆ are each independently hydrogen; heavy hydrogen; halogen; Cyano; Nitro; Amino; Substituted or unsubstituted C _1-60 alkyl; Substituted or unsubstituted C _3-60 cycloalkyl; Substituted or unsubstituted C _2-60 alkenyl; Substituted or unsubstituted C _6-60 aryl; Or substituted or unsubstituted C _2-60 heteroaryl including any one or more selected from the group consisting of N, O and S,

b1 is an integer from 0 to 7,

b2 is an integer from O to 7.

The above-described organic light emitting device is excellent in driving voltage, efficiency, and lifetime.

1 shows an example of an organic light-emitting device comprising a substrate 1, an anode 2, a hole transport layer 3, a light-emitting layer 4, and a cathode 5.
FIG. 2 shows a substrate 1, an anode 2, a hole transport layer 3, an electron blocking layer 6, a light emitting layer 4, a hole blocking layer 7, an electron transport and injection layer 8, and a cathode 5 ) Shows an example of an organic light emitting device.

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

또는

는 다른 치환기에 연결되는 결합을 의미한다. In this specification,

or

Means a bond connected to another substituent.

In the present specification, the term "substituted or unsubstituted" refers to deuterium; Halogen group; Nitrile group; Nitro group; Hydroxy group; Carbonyl group; Ester group; Imide group; Amino group; Phosphine oxide group; Alkoxy group; Aryloxy group; Alkyl thioxy group; Arylthioxy group; Alkyl sulfoxy group; Arylsulfoxy group; Silyl group; Boron group; Alkyl group; Cycloalkyl group; Alkenyl group; Aryl group; Aralkyl group; Aralkenyl group; Alkylaryl group; Alkylamine group; Aralkylamine group; Heteroarylamine group; Arylamine group; Arylphosphine group; Or it means a substituted or unsubstituted substituted or unsubstituted with one or more substituents selected from the group consisting of a heterocyclic group containing one or more of N, O and S atoms, or linked with two or more substituents among the above-exemplified substituents. . For example, "a substituent to which two or more substituents are connected" may be a biphenyl group. That is, the biphenyl group may be an aryl group or may be interpreted as a substituent to which two phenyl groups are connected.

In the present specification, the number of carbon atoms of the carbonyl group is not particularly limited, but it is 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, the ester group may be substituted with an oxygen of the ester group with a straight chain, 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 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 is specifically trimethylsilyl group, triethylsilyl group, t-butyldimethylsilyl group, vinyldimethylsilyl group, propyldimethylsilyl group, triphenylsilyl group, diphenylsilyl group, phenylsilyl group, etc. However, it is not limited thereto.

In the present specification, the boron group specifically includes a trimethyl boron group, a triethyl boron group, a t-butyldimethyl boron group, a triphenyl boron group, and a phenyl boron group, but is not limited thereto.

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

In the present specification, the alkyl group may be a linear or branched chain, and the number of carbon atoms is not particularly limited, but is preferably 1 to 40. According to an exemplary embodiment, the alkyl group has 1 to 20 carbon atoms. 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, cycloheptylmethyl, 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 a linear or branched chain, and the number of carbon atoms is not particularly limited, but is preferably 2 to 40. According to an exemplary embodiment, the alkenyl group has 2 to 20 carbon atoms. According to another exemplary embodiment, the alkenyl group has 2 to 10 carbon atoms. 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, allyl, 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 is preferably 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 cycloalkyl group has 3 to 20 carbon atoms. 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 are not limited thereto.

In the present specification, the aryl group is not particularly limited, but is preferably 6 to 60 carbon atoms, and may be a monocyclic aryl group or a polycyclic aryl group. According to an exemplary embodiment, the aryl group has 6 to 30 carbon atoms. According to an exemplary embodiment, the aryl group has 6 to 20 carbon atoms. The aryl group may be a phenyl group, a biphenyl group, or a terphenyl group, but the monocyclic aryl group 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. However, it 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 carbons is not particularly limited, but it is preferably 2 to 60 carbon atoms. According to an exemplary embodiment, the heterocyclic group has 6 to 30 carbon atoms. According to an exemplary embodiment, the number of carbon atoms of the heterocyclic group is 6 to 20. Examples of heterocyclic groups include thiophene group, furan group, pyrrole group, imidazole group, thiazole group, oxazole group, oxadiazole group, triazole group, pyridyl group, bipyridyl group, pyrimidyl group, triazine group, 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, benzoxazole group, benzoimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group, dibenzothiophene group, benzofuranyl group, phenanthroline group, thiazolyl group, Isoxazolyl group, oxadiazolyl group, thiadiazolyl group, benzothiazolyl group, phenothiazinyl group, dibenzofuranyl group, and the like, but are not limited thereto.

In the present specification, the aryl group among the aralkyl group, aralkenyl group, alkylaryl group, and arylamine group is the same as the example of the aryl group described above. 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 aforementioned alkyl group. In the present specification, for heteroaryl among heteroarylamines, the description of the aforementioned heterocyclic group may be applied. In the present specification, the alkenyl group of the aralkenyl group is the same as the example of the alkenyl group described above. In the present specification, the description of the aryl group described above may be applied except that the arylene is a divalent group. In the present specification, the description of the aforementioned heterocyclic group may be applied except that the heteroarylene is a divalent group. In the present specification, the hydrocarbon ring is not a monovalent group, and the description of the aryl group or the cycloalkyl group described above may be applied except that the hydrocarbon ring is formed by bonding of two substituents. In the present specification, the heterocycle is not a monovalent group, and the description of the above-described heterocyclic group may be applied, except that two substituents are bonded to each other.

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

Anode and cathode

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

As the anode material, a material having a large work function is preferable so that holes can be smoothly injected into the organic material layer. Specific examples of the cathode material include metals such as vanadium, chromium, copper, zinc, and 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; Poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), conductive polymers such as polypyrrole and polyaniline, and the like, but are not limited thereto.

It is preferable that the cathode material is a material having a small work function to facilitate electron injection into the organic material layer. Specific examples of the negative electrode material include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or alloys thereof; There are multi-layered materials such as LiF/Al or LiO ₂ /Al, but are not limited thereto.

Hole injection layer

The organic light-emitting device according to the present invention may further include a hole injection layer between the anode and a hole transport layer to be described later.

The hole injection material is a layer that injects holes from the electrode, and the hole injection material has the ability to transport holes, so it has a hole injection effect at the anode, an excellent hole injection effect for the light emitting layer or the light emitting material, and is generated in the light emitting layer. A compound that prevents the transfer of the excitons into the electron injection layer or the electron injection material and has excellent thin film formation ability is preferable. It is preferable that the HOMO (highest occupied molecular orbital) 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, perylene There are a series of organic substances, anthraquinone, and polyaniline and a polythiophene series of conductive polymers, but are not limited thereto.

Hole transport layer

The hole transport layer used in the present invention is a layer that receives holes from the anode or the hole injection layer formed on the anode and transports holes to the emission layer, and can be transferred to the emission layer by transporting holes from the anode or the hole injection layer as a hole transport material. A material with high mobility for holes is suitable.

Specific examples of the hole transport material include an arylamine-based organic material, a conductive polymer, and a block copolymer having a conjugated portion and a non-conjugated portion, but are not limited thereto.

E-low layer

The electron blocking layer is a layer interposed between the hole transport layer and the light emitting layer in order to prevent electrons injected from the cathode from passing over to the hole transport layer without being recombined in the light emitting layer, and is also referred to as an electron blocking layer. The electron blocking layer is preferably a material having a lower electron affinity than the electron transport layer.

Emitting layer

The light-emitting layer used in the present invention is a layer capable of emitting light in a visible light region by combining holes and electrons transferred from an anode and a cathode, and a material having good quantum efficiency against fluorescence or phosphorescence is preferable.

In general, the emission layer includes a host material and a dopant material, and may include a compound represented by Chemical Formula 1 and Chemical Formula 2 as a host. The weight ratio of the compound represented by Formula 1 and the compound represented by Formula 2 may be 99:1 to 1:99, or 90:10 to 20:80, but is not limited thereto.

Preferably, Formula 1 may be represented by any one of the following Formulas 1-1 to 1-3:

[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

In Formulas 1-1 to 1-3,

Ar ₁ , Ar ₂ , R ₁ , R ₂ , R ₃ , R ₄ , a1, a2 and a3 are as defined in Formula 1.

Preferably, Ar ₁ and Ar ₂ may each independently be a substituted or unsubstituted C _6-20 aryl,

More preferably, Ar ₁ and Ar ₂ may each independently be phenyl, biphenylyl, or naphthyl.

Preferably, at least one of Ar ₁ and Ar ₂ may be phenyl.

Preferably, R ₁ , R ₂ , R ₃ and R ₄ may each independently, independently be hydrogen, or a substituted or unsubstituted C _6-60 aryl,

More preferably, R ₁ , R ₂ , R ₃ and R ₄ may each independently, independently be hydrogen, or a substituted or unsubstituted C _6-20 aryl,

Most preferably, R ₁ , R ₂ , R ₃ and R ₄ may each independently be hydrogen or phenyl.

Preferably, R ₄ may be hydrogen.

Preferably, a1+a2+a3 may be 0 or 1.

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

.

.

The compound represented by Formula 1 may be prepared by a manufacturing method such as the following Scheme 1 or Scheme 2, for example, and other compounds may be prepared similarly.

[Scheme 1]

[Scheme 2]

In Scheme 1 and Scheme 2, Ar ₁ , Ar ₂ , R ₁ , R ₂ , R ₃ , R ₄ , a1, a2 and a3 are as defined in Formula 1, and X ₁ , X ₂ , X ₃ and X ₄ is halogen, preferably, X ₁ , X ₂ , X ₃ and X ₄ are each independently chloro or bromo.

Step 1, Step 3 of Scheme 1, and Steps 1 to 3 of Scheme 2 are each Suzuki coupling reaction, preferably carried out in the presence of a palladium catalyst and a base, and the reactor for the Suzuki coupling reaction is known in the art. It can be changed according to the bar. Step 2 of Scheme 1 is a Bromination reaction, and as a bromo source, NBS, Br ₂ , FeBr _3, etc., may be freely used, without limitation, as known in the art. The manufacturing method may be more specific in the manufacturing examples to be described later.

Preferably, Ar ₃ and Ar ₄ are each independently substituted or unsubstituted C _6-20 aryl; Or substituted or unsubstituted N, O and S may be a C _2-20 heteroaryl including any one or more selected from the group consisting of,

More preferably, Ar ₃ and Ar ₄ may each independently be phenyl, biphenylyl, terphenylyl, naphthyl, diphenzofuranyl, dibenzothiophenyl, or dimethylfluorenyl.

Preferably, at least one of Ar ₃ and Ar ₄ may be a substituted or unsubstituted C _6-20 aryl,

More preferably, at least one of Ar ₃ and Ar ₄ may be phenyl or biphenylyl.

Preferably, R ₅ and R ₆ may each be hydrogen.

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

.

.

The compound represented by Formula 2 may be prepared by the same method as in Scheme 3 below, and other compounds may be prepared similarly.

[Scheme 3]

In Scheme 3, Ar ₃ , Ar ₄ , R ₅ , R ₆ , b1 and b2 are the same as defined in Formula 2, X ₅ and X ₆ are halogen, preferably, X ₅ and X ₆ are each Independently chloro or bromo.

Step 1 of Scheme 3 is a Suzuki coupling reaction, preferably carried out in the presence of a palladium catalyst and a base, and the reactor for the Suzuki coupling reaction can be changed as known in the art. Step 2 of Scheme 3 is an amine substitution reaction, preferably performed in the presence of a palladium catalyst and a base, and the reactor for the amine substitution reaction may be changed as known in the art. The manufacturing method may be more specific in the manufacturing examples to be described later.

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

Hole bottom

The hole blocking layer is a layer placed between the electron transport layer and the light emitting layer to prevent holes injected from the anode from being recombined in the light emitting layer and passing to the electron transport layer, and is also called a hole suppressing layer. A material having high ionization energy is preferable for the hole blocking layer.

Electron transport layer

The organic light-emitting device according to the present invention may include an electron transport layer between the emission 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 emission layer, and inhibits the transfer of holes from the emission layer. As an electron transport material, electrons are well injected from the cathode. As a material that can be received and transferred to the emission layer, a material having high mobility for electrons is suitable. As the electron transport material, a material capable of receiving electrons from the cathode and transferring them to the light emitting layer, and a material having high mobility for electrons 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 can be used with any desired cathode material as used according to the prior art. In particular, examples of suitable cathode materials are conventional materials that have a low work function and are followed by an aluminum layer or a silver layer. Specifically, they are cesium, barium, calcium, ytterbium and samarium, and in each case an aluminum layer or a silver layer follows.

Electron injection layer

The organic light-emitting device according to the present invention may further include an electron injection layer between the electron transport layer and the cathode. 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 A compound that prevents migration to the layer and has excellent thin film formation ability is preferable.

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

Examples of the metal complex compound include lithium 8-hydroxyquinolinato, 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-cresolato)gallium, bis(2-methyl-8-quinolinato)(1-naphtholato)aluminum, bis(2-methyl-8-quinolinato)(2-naphtholato)gallium, etc. It is not limited to this.

On the other hand, in the present invention, the "electron injection and transport layer" is a layer that performs both the role of the electron injection layer and the electron transport layer, and a material serving as the respective layer may be used alone or in combination, but is limited thereto. It doesn't work.

Organic light emitting element

The structure of the organic light emitting device according to the present invention is illustrated in FIG. 1. 1 shows an example of an organic light-emitting device comprising a substrate 1, an anode 2, a hole transport layer 3, a light-emitting layer 4, and a cathode 5. In addition, the structure of the organic light emitting device in the case of including the electron blocking layer 6, the hole blocking layer 7 and the electron transport and injection layer 8 is illustrated in FIG. 2.

The organic light emitting device according to the present invention can be manufactured by sequentially stacking the above-described configurations. At this time, using a PVD (physical vapor deposition) method such as sputtering or e-beam evaporation, the anode is formed by depositing a metal or a conductive metal oxide or an alloy thereof on the substrate. And, after forming each of the above-described 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 a cathode material, an organic material layer, and an anode material on a substrate. In addition, the light emitting layer may be formed by a solution coating method as well as a vacuum deposition method of a host and a dopant. Here, the solution coating 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.

In addition to such a method, an organic light-emitting device may be manufactured by sequentially depositing an organic material layer and an anode material from a cathode material on a substrate (WO 2003/012890). However, the manufacturing method is not limited thereto.

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

Hereinafter, it will be described in more detail to aid the understanding of the present invention. However, the following examples are merely illustrative of the present invention, and the contents of the present invention are not limited by the following examples.

Preparation Example 1: Synthesis of Compound 1-1

Dissolve dibenzo[b,d]thiophen-4-ylboronic acid (intermediate b1, 15.0 g, 65.8 mmol) and intermediate a1 (21.1 g, 78.9 mmol) in tetrahydrofuran (THF, 300 ml) in a three-necked flask and potassium carbonate (K ₂ CO ₃ , 36.4 g, 263.1 mmol) was dissolved in water (150 ml). Here, tetrakis(triphenylphosphine)palladium(0) (Pd(PPh ₃ ) ₄ , 3.8 g, 3.3 mmol) was added and stirred for 8 hours under reflux conditions in an argon atmosphere. Upon completion of the reaction, after cooling to room temperature, the reaction solution was transferred to a separatory funnel, and extracted with CH ₂ Cl ₂ . The extract was dried over MgSO ₄ , filtered and concentrated, and the sample was purified by silica gel column chromatography to obtain Intermediate 1-1-A (20.2 g, yield 74%).

MS: [M+H] ⁺ = 415

Intermediate 1-1-A (20.0 g, 40.7 mmol), N-bromosuccinimide (NBS, 8.7 g, 48.8 mmol), dimethylformamide (DMF, 400 ml) was added to a two necked flask, and stirred at room temperature for 5 hours under an argon atmosphere. . After completion of the reaction, the reaction solution was transferred to a separatory funnel, water was added, and ethyl acetate was used for extraction. The sample was purified by silica gel column chromatography to obtain Intermediate 1-1-B (17.8 g, 75% yield).

MS[M+H] ⁺ = 494

In a three neck flask, intermediate 1-1-B (15.0 g, 30.3 mmol) and intermediate b1 (8.3 g, 36.4 mmol) were dissolved in THF (300 ml), and K ₂ CO ₃ (16.8 g, 121.4 mmol) was added to water (150 ml). Pd(PPh ₃ ) ₄ (1.8 g, 1.5 mmol) was added thereto, and the mixture was stirred for 8 hours under reflux conditions in an argon atmosphere. Upon completion of the reaction, after cooling to room temperature, the reaction solution was transferred to a separatory funnel, and extracted with CH ₂ Cl ₂ . The extract was dried over MgSO ₄ , filtered and concentrated, and the sample was purified by silica gel column chromatography to obtain compound 1-1 (6.2 g, yield 34%) through sublimation purification.

MS: [M+H] ⁺ = 597

Preparation Example 2: Synthesis of Compound 1-2

In Preparation Example 1, compound 1-2 was prepared in the same manner as in the preparation method of compound 1-1, except that intermediate b1 was changed to intermediate b2 and used.

MS: [M+H] ⁺ = 597

Preparation Example 3: Synthesis of Compound 1-3

In Preparation Example 1, compound 1-3 was prepared in the same manner as in the preparation method of compound 1-1, except that intermediate a1 was changed to intermediate a2 and intermediate b1 was changed to intermediate b3.

MS: [M+H] ⁺ = 673

Preparation Example 4: Synthesis of Compound 1-4

Dissolve 4,6-dibromodibenzo[b,d]thiophene (20.0 g, 58.5 mmol) and intermediate b1 (14.7 g, 64.3 mmol) in THF (400 ml) in a three necked flask, and K ₂ CO ₃ (32.3 g, 233.9 mmol) ) Was dissolved in water (200 ml). Pd(PPh ₃ ) ₄ (3.4 g, 2.9 mmol) was added thereto, and the mixture was stirred for 8 hours under reflux conditions in an argon atmosphere. Upon completion of the reaction, after cooling to room temperature, the reaction solution was transferred to a separatory funnel, and extracted with CH ₂ Cl ₂ . The extract was dried over MgSO ₄ , filtered and concentrated, and the sample was purified by silica gel column chromatography to obtain Intermediate 1-4-A (17.7 g, yield 68%).

MS: [M+H] ⁺ = 445

Intermediate 1-4-A (17.0 g, 38.2 mmol), bis(pinacolato)diboron (11.6 g, 45.8 mmol), bis(dibenzylideneacetone) palladium(0) (Pd(dba) ₂ , 0.4 g, 0.8 in a three necked flask) mmol), tricyclohexylphosphine (PCy ₃ , 0.4 g, 1.5 mmol), potassium acetate (KOAc, 7.5 g, 76.3 mmol), and 1,4-dioxane (255 ml) were added, and stirred for 12 hours under reflux conditions in an argon atmosphere. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was transferred to a separatory funnel, and extracted with water and ethyl acetate. The extract was dried over MgSO ₄ , filtered and concentrated, and the sample was purified by silica gel column chromatography to obtain Intermediate 1-4-B (12.8 g, yield 68%).

MS: [M+H] ⁺ = 492

In a three neck flask, intermediate 1-4-B (12.0 g, 24.4 mmol) and intermediate a1 (7.8 g, 29.2 mmol) were dissolved in THF (240 ml), and K ₂ CO ₃ (13.5 g, 97.5 mmol) was added to water (120 ml). Pd(PPh ₃ ) ₄ (1.4 g, 1.2 mmol) was added thereto, and the mixture was stirred for 8 hours under reflux conditions in an argon atmosphere. Upon completion of the reaction, after cooling to room temperature, the reaction solution was transferred to a separatory funnel, and extracted with CH ₂ Cl ₂ . The extract was dried over MgSO ₄ , filtered and concentrated, and the sample was purified by silica gel column chromatography to obtain compound 1-4 (4.5 g, yield 31%) through sublimation purification.

MS: [M+H] ⁺ = 597

Preparation Example 5: Synthesis of Compound 1-5

In Preparation Example 4, compound 1-5 was prepared in the same manner as in the preparation method of compound 1-4, except that intermediate b1 was changed to intermediate b2 and used.

MS: [M+H] ⁺ = 597

Preparation Example 6: Synthesis of Compound 1-6

In a three necked flask, 3-bromo-6-chlorodibenzo[b,d]thiophene (20.0 g, 67.2 mmol) and intermediate b2 (22.9 g, 73.9 mmol) were dissolved in THF (400 ml) and K ₂ CO ₃ (37.2 g, 268.8 mmol) was dissolved in water (200 ml). Pd(PPh ₃ ) ₄ (3.9 g, 3.4 mmol) was added thereto, and the mixture was stirred for 8 hours under reflux conditions in an argon atmosphere. Upon completion of the reaction, after cooling to room temperature, the reaction solution was transferred to a separatory funnel, and extracted with CH ₂ Cl ₂ . The extract was dried over MgSO ₄ , filtered and concentrated, and the sample was purified by silica gel column chromatography to obtain Intermediate 1-6-A (20.2 g, yield 75%).

MS: [M+H] ⁺ = 400

Intermediate 1-6-A (20.0 g, 49.9 mmol), bis(pinacolato) diboron (15.2 g, 59.9 mmol), Pd(dba) ₂ (0.6 g, 1.0 mmol), PCy ₃ (0.6 g, 2.0 mmol), KOAc (9.8 g, 99.8 mmol), and 1,4-dioxane (300 ml) were added, and the mixture was stirred for 12 hours under reflux conditions in an argon atmosphere. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was transferred to a separatory funnel, and extracted with water and ethyl acetate. The extract was dried over MgSO 4, filtered and concentrated, and the sample was purified by silica gel column chromatography to obtain Intermediate 1-6-B (15.2 g, yield 62%).

MS: [M+H] ⁺ = 492

In a 3-neck flask, intermediate 1-6-B (15.0 g, 30.5 mmol) and intermediate a1 (9.8 g, 36.6 mmol) were dissolved in THF (300 ml), and K ₂ CO ₃ (16.8 g, 121.8 mmol) was added to water (150 ml). Pd(PPh ₃ ) ₄ (1.8 g, 1.5 mmol) was added thereto, and the mixture was stirred for 8 hours under reflux conditions in an argon atmosphere. Upon completion of the reaction, after cooling to room temperature, the reaction solution was transferred to a separatory funnel, and extracted with CH ₂ Cl ₂ . The extract was dried over MgSO ₄ , filtered and concentrated, and the sample was purified by silica gel column chromatography, and then compound 1-6 (5.8 g, yield 32%) was obtained through sublimation purification.

MS: [M+H] ⁺ = 597

Preparation Example 7: Synthesis of Compound 1-7

In a three neck flask, 3,7-dibromodibenzo[b,d]thiophene (20.0 g, 58.5 mmol), intermediate b4 (24.8 g, 64.3 mmol) was dissolved in THF (400 ml), and K ₂ CO ₃ (32.3 g, 233.9 mmol) was dissolved. ) Was dissolved in water (200 ml). Pd(PPh ₃ ) ₄ (3.4 g, 2.9 mmol) was added thereto, and the mixture was stirred for 8 hours under reflux conditions in an argon atmosphere. Upon completion of the reaction, after cooling to room temperature, the reaction solution was transferred to a separatory funnel, and extracted with CH ₂ Cl ₂ . The extract was dried over MgSO ₄ , filtered and concentrated, and the sample was purified by silica gel column chromatography to obtain Intermediate 1-7-A (23.5 g, yield 77%).

MS: [M+H] ⁺ = 521

Intermediate 1-7-A (20.0 g, 38.4 mmol), bis(pinacolato) diboron (11.7 g, 46.0 mmol), Pd(dba) ₂ (0.4 g, 0.8 mmol), PCy ₃ (0.4 g, 1.5 mmol), KOAc (7.5 g, 76.7 mmol), and 1,4-dioxane (300 ml) were added, and the mixture was stirred for 12 hours under reflux conditions in an argon atmosphere. After the reaction was completed, the mixture was cooled to room temperature, and the reaction solution was transferred to a separatory funnel, and extracted with water and ethyl acetate. The extract was dried over MgSO ₄ , filtered and concentrated, and the sample was purified by silica gel column chromatography to obtain Intermediate 1-7-B (14.8 g, yield 68%).

MS: [M+H] ⁺ = 568

In a 3-neck flask, intermediate 1-7-B (14.0 g, 24.6 mmol) and intermediate a1 (7.9 g, 29.5 mmol) were dissolved in THF (280 ml), and K ₂ CO ₃ (13.6 g, 98.5 mmol) was added to water (140 ml). Pd(PPh ₃ ) ₄ (1.4 g, 1.2 mmol) was added thereto, and the mixture was stirred for 8 hours under reflux conditions in an argon atmosphere. Upon completion of the reaction, after cooling to room temperature, the reaction solution was transferred to a separatory funnel, and extracted with CH ₂ Cl ₂ . The extract was dried over MgSO ₄ , filtered and concentrated, and the sample was purified by silica gel column chromatography to obtain compound 1-7 (4.1 g, yield 25%) through sublimation purification.

MS: [M+H] ⁺ = 673

Preparation Example 8: Synthesis of Compound 2-1

Dissolve 3-bromo-9H-carbazole (10.0 g, 40.6 mmol) and intermediate c1 (19.0 g, 42.7 mmol) in THF (400 ml) in a three-neck flask, and add K ₂ CO ₃ (22.5 g, 162.5 mmol) in water ( 200 ml). Pd(PPh ₃ ) ₄ (0.5 g, 0.4 mmol) was added thereto, and the mixture was stirred for 8 hours under reflux conditions in an argon atmosphere. Upon completion of the reaction, after cooling to room temperature, the reaction solution was transferred to a separatory funnel, and extracted with CH ₂ Cl ₂ . The extract was dried over MgSO ₄ , filtered and concentrated, and the sample was purified by silica gel column chromatography to obtain Intermediate 2-1-A (14.8 g, yield 75%).

MS: [M+H] ⁺ = 484

In a three-neck flask, intermediate 2-1-A (14.0 g, 28.9 mmol) and intermediate d1 (7.4 g, 31.8 mmol) were dissolved in toluene (280 ml), and sodium tert-butoxide (NaOtBu, 4.2 g, 43.3 mmol), bis (tri-tert-butylphosphine)palladium(0) (Pd(P(t-Bu) ₃ ) ₂ , 0.3 g, 0.6 mmol) was added, followed by stirring for 6 hours under reflux conditions in an argon atmosphere. When the reaction was completed, the mixture was cooled to room temperature, water (200 ml) was added, and the reaction solution was transferred to a separatory funnel for extraction. The extract was dried over MgSO ₄ , concentrated, and the sample was purified by silica gel column chromatography, and then compound 2-1 (6.4 g, yield 35%) was obtained through sublimation purification.

MS: [M+H] ⁺ = 636

Preparation Example 9: Synthesis of Compound 2-2

In Synthesis Example 8, compound 2-2 was prepared in the same manner as in the preparation method of compound 2-1, except that intermediate c1 was changed to intermediate c2 and intermediate d1 was changed to intermediate d2.

MS: [M+H] ⁺ = 574

Preparation Example 10: Synthesis of Compound 2-3

In Synthesis Example 8, compound 2-3 was prepared in the same manner as in the preparation method of compound 2-1, except that intermediate c1 was changed to intermediate c2 and intermediate d1 was changed to intermediate d3.

MS: [M+H] ⁺ = 600

Example 1

A glass substrate coated with a thin film of 1400 Å of ITO (Indium Tin Oxide) was put in distilled water dissolved in a detergent and washed with ultrasonic waves. In this case, Fischer Co. product was used as a detergent, and distilled water secondarily filtered with a filter made by Millipore Co. was used as distilled water. After washing the ITO for 30 minutes, it was repeated twice with distilled water to perform ultrasonic cleaning for 10 minutes. 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.

On the thus prepared ITO transparent electrode, the following compound HT-A and the following compound PD were thermally vacuum deposited to a thickness of 100 Å in a weight ratio of 95:5, and then only the compound HT-A was deposited to a thickness of 1150 Å to form a hole transport layer. The following compound HT-B was thermally vacuum deposited to a thickness of 450 Å as an electron blocking layer thereon. Then, the compound 1-1 prepared in Preparation Example 1 was used as the first host of the light-emitting layer, the compound 2-1 prepared in Preparation Example 8 was used as the second host, and the following compound GD was used as a dopant at 40:60:15. It was vacuum-deposited to a thickness of 400 Å using the weight ratio of. Subsequently, the following compound ET-A was vacuum deposited to a thickness of 50 Å as a hole blocking layer. Subsequently, as an electron transport and injection layer, the following compounds ET-B and Liq in a weight ratio of 2:1 were thermally vacuum deposited to a thickness of 250 Å, followed by LiF and magnesium in a weight ratio of 1:1 to a thickness of 30 Å. I did. On the electron transport and injection layer, magnesium and silver were deposited in a weight ratio of 1:4 to a thickness of 160 Å to form a cathode, thereby manufacturing an organic light-emitting device.

Examples 2 to 14

Organic light emitting devices were each manufactured in the same manner as in Example 1, except that the host material was changed as shown in Table 1 below. In this case, when a mixture of two types of compounds is used as the host, the parentheses mean the weight ratio between the host compounds.

Comparative Examples 1 to 7

Organic light emitting devices were each manufactured in the same manner as in Example 1, except that the host material was changed as shown in Table 1 below. In this case, when a mixture of two types of compounds is used as the host, the parentheses mean the weight ratio between the host compounds. In Table 1 below, GH-A and GH-B refer to the following compounds, respectively.

Experimental example

By applying a current to the organic light emitting device prepared in Examples 1 to 14 and Comparative Examples 1 to 7, voltage, efficiency, and life (T95) were measured, and the results are shown in Table 1 below. At this time, voltage and efficiency were measured by applying a current density of 10 mA/cm ² , and T95 refers to the time from the current density of 20 mA/cm ² until the initial luminance decreases to 95%.

Host material @ 10mA / cm ² @ 20mA / cm ² Voltage (V) Efficiency (cd/A) Life (T95, hr) Example 1 Compound 1-1: Compound 2-1
(40:60) 4.45 56.5 130 Example 2 Compound 1-2: Compound 2-1 (40:60) 4.48 56.1 130 Example 3 Compound 1-3: Compound 2-1 (40:60) 4.43 55.9 125 Example 4 Compound 1-4: Compound 2-1 (40:60) 4.40 55.2 140 Example 5 Compound 1-5: Compound 2-1 (40:60) 4.42 53.0 130 Example 6 Compound 1-6: Compound 2-1 (40:60) 4.43 54.1 125 Example 7 Compound 1-7: Compound 2-1 (40:60) 4.47 55.5 140 Example 8 Compound 1-1: Compound 2-2 (40:60) 4.27 57.1 130 Example 9 Compound 1-3: Compound 2-2 (40:60) 4.25 58.4 125 Example 10 Compound 1-5: Compound 2-2 (40:60) 4.28 58.2 135 Example 11 Compound 1-7: Compound 2-2 (40:60) 4.24 57.1 125 Example 12 Compound 1-2: Compound 2-3 (40:60) 4.37 55.4 120 Example 13 Compound 1-4: Compound 2-3 (40:60) 4.31 54.2 120 Example 14 Compound 1-6: Compound 2-3 (40:60) 4.35 54.5 130 Comparative Example 1 Compound 1-2 4.78 48.1 110 Comparative Example 2 Compound 1-4 4.87 48.7 110 Comparative Example 3 Compound 1-5 4.80 49.1 105 Comparative Example 4 GH-A 5.31 28.0 9 Comparative Example 5 GH-B 5.23 35.3 45 Comparative Example 6 GH-A: compound 2-1 (40:60) 4.88 38.1 65 Comparative Example 7 GH-B: compound 2-1 (40:60) 4.97 40.1 80

As shown in Table 1 above, when the compound represented by Formula 1 and the compound represented by Formula 2 are applied together as a host of the emission layer, lower driving than Comparative Examples 1 to 3, which are organic light emitting devices using only the compound represented by Formula 1 It was found that it exhibits the characteristics of voltage, high efficiency, and long life.

In addition, when compared with Comparative Example 4 in which a compound containing dibenzofuran and dibenzothiophene as a host was used as a host, the characteristics of the low voltage, high efficiency, and long life of the present invention were evident, and the GH used in Comparative Example 4 Comparative Example 6, which is an organic light-emitting device in which -A was used as a host together with the compound represented by Chemical Formula 2, also showed inferior driving voltage, efficiency, and lifetime compared to the exemplary embodiment of the present invention.

On the other hand, in Example 2 including Compound 1-2 in which the triazinyl substitution position of the compound represented by Formula 1 is carbon 1 of dibenzothiophenyl, and in Example 2, the substitution position of triazinyl is carbon 4 Comparing Comparative Example 7 using the only different compound GH-B, the organic light-emitting device of the present invention exhibits excellent characteristics of low driving voltage, high efficiency, and long life.

That is, when the compound represented by Formula 1 is used as a host of an organic light emitting device, it can be inferred that triazinyl exhibits characteristics of lower voltage, high efficiency, and longer life than a material substituted with carbon 4 of dibenzothiophenyl. This could also be confirmed through a comparison of Comparative Example 1 in which Compound 1-2 was used and Comparative Example 5 using GH-B.

1: substrate 2: anode
3: hole transport layer 4: light emitting layer
5: cathode 6: electron blocking layer
7: hole blocking layer 8: electron transport and injection layer

Claims (12)

anode,
cathode,
Comprising a light emitting layer between the anode and the cathode,
The emission layer comprises a compound represented by the following formula (1) and a compound represented by the following formula (2),
Organic light emitting element:
[Formula 1]

In Formula 1,
Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted C _6-60 aryl,
R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen; heavy hydrogen; halogen; Cyano; Nitro; Amino; Substituted or unsubstituted C _1-60 alkyl; Substituted or unsubstituted C _3-60 cycloalkyl; Substituted or unsubstituted C _2-60 alkenyl; Substituted or unsubstituted C _6-60 aryl; Or substituted or unsubstituted C _2-60 heteroaryl including any one or more selected from the group consisting of N, O and S,
a1 is an integer from 0 to 7,
a2 is an integer from 0 to 3,
a3 is an integer from 0 to 2,
[Formula 2]

In Chemical Formula 2,
Ar ₃ and Ar ₄ are each independently a substituted or unsubstituted C _6-60 aryl; Or substituted or unsubstituted C _2-60 heteroaryl including any one or more selected from the group consisting of N, O and S,
R ₅ and R ₆ are each independently hydrogen; heavy hydrogen; halogen; Cyano; Nitro; Amino; Substituted or unsubstituted C _1-60 alkyl; Substituted or unsubstituted C _3-60 cycloalkyl; Substituted or unsubstituted C _2-60 alkenyl; Substituted or unsubstituted C _6-60 aryl; Or substituted or unsubstituted C _2-60 heteroaryl including any one or more selected from the group consisting of N, O and S,
b1 is an integer from 0 to 7,
b2 is an integer from O to 7.
The method of claim 1,
Formula 1 is represented by any one of the following Formulas 1-1 to 1-3,
Organic light emitting element:
[Formula 1-1]

[Formula 1-2]

[Formula 1-3]

In Formulas 1-1 to 1-3,
Descriptions of Ar ₁ , Ar ₂ , R ₁ , R ₂ , R ₃ , R ₄ , a1, a2 and a3 are as defined in claim 1.
The method of claim 1,
Ar ₁ and Ar ₂ are each independently phenyl, biphenylyl, or naphthyl,
Organic light emitting device.
The method of claim 1,
At least one of Ar ₁ and Ar ₂ is phenyl,
compound.
The method of claim 1,
R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or phenyl,
Organic light emitting device.
The method of claim 1,
R ₄ is hydrogen,
Organic light emitting device.
The method of claim 1,
a1+a2+a3 is 0, or 1,
Organic light emitting device.
The method of claim 1,
The compound represented by Formula 1 is any one selected from the group consisting of,
Organic light emitting element:

.
The method of claim 1,
Ar ₃ and Ar ₄ are each independently phenyl, biphenylyl, terphenylyl, naphthyl, diphenzofuranyl, dibenzothiophenyl, or dimethylfluorenyl,
Organic light emitting device.
The method of claim 1,
At least one of Ar ₃ and Ar ₄ is phenyl, or biphenylyl,
Organic light emitting device.
The method of claim 1,
R ₅ and R ₆ are each hydrogen,
Organic light emitting device.
The method of claim 1,
The compound represented by Formula 2 is any one selected from the group consisting of,
Organic light emitting element:

.

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