KR102252291B1 - Organic light emitting device - Google Patents

Abstract

The present invention provides an organic light emitting device.

Description

Organic light emitting device TECHNICAL FIELD

The present invention relates to an organic light-emitting device having a low driving voltage, high luminous efficiency, and excellent lifespan.

In general, the organic light emission phenomenon refers to a phenomenon in which electrical energy is converted into light energy by 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.

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 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. When it falls back to the ground, it glows.

Development of new materials for organic materials used in organic light emitting devices as described above is continuously required.

Korean Patent Publication No. 10-2000-0051826

The present invention relates to an organic light-emitting device having a low driving voltage, high luminous efficiency, and excellent lifespan.

In order to solve the above problems, the present invention provides the following organic light emitting device.

The organic light-emitting device according to the present invention,

anode; Light-emitting layer; Electron transport layer; And a cathode,

The emission layer includes a first compound having an LUMO energy level of 2.6 eV to 3.0 eV,

The electron transport layer includes a second compound having an LUMO energy level of 2.4 eV to 2.8 eV,

The second compound is represented by the following formula (2):

[Formula 2]

In Chemical Formula 2,

L ₃ to L ₅ are each independently a single bond; Or a substituted or unsubstituted C _6-60 arylene,

k is 0, 1, or 2,

Ar ₃ and Ar ₄ are each independently phenyl unsubstituted or substituted with cyano; Biphenylyl unsubstituted or substituted with cyano; Or terphenylyl unsubstituted or substituted with cyano, but at least one of _{Ar 3} and Ar _{4 is phenyl substituted with cyano;} Biphenylyl substituted with cyano; Or terphenylyl substituted with cyano,

A is a monovalent substituent of the compound represented by the following formula (3),

[Formula 3]

In Chemical Formula 3,

T _{1 is a C 6-20} aromatic ring fused with a neighboring pentagonal ring,

,

,

, 또는

이고,X ₁ is

,

,

, or

ego,

W ₁ is a single bond, O, S, CR ₅ R ₆ , SiR ₇ R ₈ , or NR ₁₀ ,

Z ₁ and Z ₂ are each independently hydrogen; heavy hydrogen; Substituted or unsubstituted C _1-60 alkyl,

R ₁ to R ₈ are each independently hydrogen; heavy hydrogen; Substituted or unsubstituted C _6-60 aryl; _{Or a substituted or unsubstituted C 2-60} heteroaryl containing one or more heteroatoms selected from the group consisting of N, O and S _{, or a C 6-60} spiro ring by bonding of adjacent substituents to each other; Or can form a _{C 6-60 aromatic ring,}

R ₁₀ is bonded to each other with an adjacent substituent R ₃ to form _{a C 2-60 heteroaromatic ring containing at least one N atom,}

a1 to a4 are each independently an integer of 0 to 4,

When a1 to a4 are each 2 or more, the structures in the two or more parentheses are the same as or different from each other.

The organic light-emitting device described above may exhibit low driving voltage, high luminous efficiency, and long lifespan characteristics by using a light emitting layer and an electron transport layer material having a specific LUMO energy level.

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

는 다른 치환기에 연결되는 결합을 의미한다.In this specification,

Means a bond connected to another substituent.

In the present specification, the term "substituted or unsubstituted" refers to deuterium; Halogen group; Cyano 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 substituted or unsubstituted with one or more substituents selected from the group consisting of a heteroaryl group containing one or more of N, O, and S atoms, or substituted or unsubstituted with two or more substituents connected 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 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 a C1-C25 linear, branched or cyclic alkyl group or an aryl group having 6 to 25 carbon atoms in the oxygen of the ester group. 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, a phenyl boron group, and the like, 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 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 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 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 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 phenanthrenyl 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,

Can be, etc. However, it is not limited thereto.

In the present specification, heteroaryl is a heteroaryl containing one or more of O, N, Si, and S as heterogeneous elements, and the number of carbons is not particularly limited, but is preferably 2 to 60 carbon atoms. Examples of heteroaryl 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, 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, isoxazolyl group, thiadiazolyl Group, a phenothiazinyl group, a 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, the heteroaryl among the heteroarylamines may be described above for heteroaryl. 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 above-described heteroaryl 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 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 heteroaryl may be applied except that the heterocycle is formed by bonding of two substituents.

In order to obtain a high-efficiency organic light-emitting device capable of driving at a low voltage, holes and electrons injected into the organic light-emitting device are smoothly transferred to the light-emitting layer, and holes and electrons injected into the light-emitting layer must not escape out of the light-emitting layer. For this, a material having an appropriate HOMO (Highest occupied molecular orbital) energy level, LUMO (Lowest Unoccupied Molecular Orbital) energy level, and a bandgap should be used. In particular, the LUMO energy level of the host material used for the light emitting layer and the material used for the electron transport layer is important in terms of controlling the charge balance of the entire device.

At this time, the term'LUMO energy level' used in the present specification means the distance from the vacuum level to the lowest unoccupied molecular orbital, and'HOMO energy level' means the distance from the vacuum level to the highest occupied molecular orbital, Even when the energy level is displayed in the negative (-) direction from the vacuum level, the energy level is interpreted to mean the absolute value of the corresponding energy value.

The LUMO energy level can be obtained after measuring the HOMO energy level, and the HOMO energy level is UV photoelectron spectroscopy that measures the ionization potential (IP) of a material by detecting electrons that protrude when UV is irradiated on the surface of a thin film. (ultraviolet photoemission spectroscopy, UPS) can be obtained experimentally. At this time, the HOMO energy level and the LUMO energy level may be calculated as shown in Equation 1 below.

[Equation 1]

HOMO (eV) = IP

LUMO (eV) = HOMO-Optical energy gap

Alternatively, the HOMO energy level and the LUMO energy level can be measured using oxidation potential and reduction potential obtained through voltage sweep after dissolving the substance to be measured together with an electrolyte in a solvent. have.

Specifically, the HOMO energy level is measured by measuring the onset potential (E _onset ) at which oxidation of the substance to be measured starts, and measuring the potential of ferrocene (E _1/2(Fc) ) under the same conditions, and then measuring the potential of ferrocene as the vacuum energy level. It can be calculated by Equation 2 below by setting the contrast to 4.8 eV.

[Equation 2]

HOMO (eV) = 4.8 + (E _onset -E _1/2(Fc) )

In addition, the LUMO energy level may be calculated by Equation 3 below _{, using the absorption spectrum, and converting the energy unit with the absorption edge wavelength (λ edge) of the material to be measured as a band gap.} In this case, the band gap means the difference between the LUMO energy level and the HOMO energy level.

[Equation 3]

Bandgap (eV) = 1240 / λ _edge

LUMO　(eV) = HOMO (eV)-Bandgap (eV)

Meanwhile, the organic light emitting device according to the present invention includes a host material and an electron transport material having a specific LUMO energy level in each of the light emitting layer and the electron transport layer, so that electrons injected from the cathode are smoothly transferred to the light emitting layer, and the transferred electrons are holed. And is efficiently recombined, resulting in a low driving voltage and high efficiency.

Specifically, the emission layer of the organic light-emitting device includes a host material exhibiting an LUMO energy level of 2.6 eV to 3.0 eV, and the electron transport layer includes an electron transport material exhibiting an LUMO energy level of 2.4 eV to 2.8 eV. Such a host material is an anthracene-based compound and has a structure represented by Formula 1 to be described later, and the electron transport material is a triazine-based compound and has a structure represented by Formula 2 to be described later, including at least one cyano group. When the LUMO energy level of the host material is out of the above-described range, electrons may be leaked from the emission layer to the adjacent layer, and when the LUMO energy level of the electron transport material is outside the above-described range, the emission layer in the electron transport layer Electron movement to the vehicle may be impeded. Accordingly, in the light emitting layer and the electron transport layer according to the present invention, the LUMO levels of molecules through which electrons can move are properly aligned to improve the characteristics of the organic light emitting device.

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

Anode and cathode

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 multilayered 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 on the anode for injecting holes from the electrode.

The hole injection layer is made of a hole injection material, and the hole injection material has the ability to transport holes, and thus has a hole injection effect at the anode, an excellent hole injection effect for the light emitting layer or the light emitting material, and excitons generated in the light emitting layer A compound that prevents migration to 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 organic light-emitting device according to the present invention may further include a hole injection layer for injecting holes from an electrode on the hole injection layer.

As a hole transport material, a material having high mobility for holes is suitable as a material capable of transporting holes from the anode or the hole injection layer and transferring them to the emission layer. Specific examples include an arylamine-based organic material, a conductive polymer, and a block copolymer including a conjugated portion and a non-conjugated portion, but are not limited thereto.

Light emitting layer

The emission layer includes a first compound having an LUMO energy level of 2.6 eV to 3.0 eV as a host material.

The first compound is represented by the following formula (1):

[Formula 1]

In Formula 1,

L ₁ and L ₂ are each independently a single bond; Or a substituted or unsubstituted C _6-60 arylene,

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

Q ₁ and Q ₂ are each independently hydrogen; heavy hydrogen; halogen; Cyano; Nitro; Amino; Substituted or unsubstituted C _1-60 alkyl; C _1-60 haloalkyl; Substituted or unsubstituted C _1-60 haloalkoxy; Substituted or unsubstituted C _3-60 cycloalkyl; Substituted or unsubstituted C _2-60 alkenyl; Substituted or unsubstituted C _6-60 aryl; _{Or a substituted or unsubstituted C 2-60} heteroaryl including at least one of O, N, Si and S,

n1 and n2 are each independently an integer of 0 to 4,

When n1 and n2 are each 2 or more, the structures in the two or more parentheses are the same as or different from each other.

In Formula 1, L ₁ and L ₂ may each independently be a single bond, or C _6-20 arylene.

Specifically, L ₁ and L ₂ may each independently be a single bond, phenylene, naphthylene, or anthracenylene.

In addition, Ar ₁ and Ar ₂ are each independently, unsubstituted, or C _1-4 alkyl; Or it may be a _{C 6-10} aryl substituted with tri(C _1-4 alkyl)silyl.

Specifically, Ar ₁ and Ar ₂ may each independently be phenyl, tert-butylphenyl, trimethylsilylphenyl, or naphthyl.

In addition, both Q ₁ and Q ₂ may be hydrogen.

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

The first compound represented by Formula 1 may be prepared by a manufacturing method as shown in Scheme 1 below, for example.

[Scheme 1]

In Reaction Scheme 1, _{descriptions for Ar 1} , Ar ₂ , L ₁ , L ₂ , Q ₁ and Q ₂ are as defined in Chemical Formula 1, and X is halogen, preferably bromo or chloro. The reaction is a Suzuki coupling reaction, preferably carried out in the presence of a palladium catalyst, and the reactor for the Suzuki coupling reaction can be changed as known in the art. The manufacturing method may be more specific in the manufacturing examples to be described later.

In addition, the light-emitting layer may further include a host material commonly used in addition to the first compound, such as a condensed aromatic ring derivative or a heterocyclic-containing compound. Specifically, condensed aromatic ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, and fluoranthene compounds, and heterocycle-containing compounds include carbazole derivatives, dibenzofuran derivatives, ladder type Furan compounds, pyrimidine derivatives, and the like, but are not limited thereto.

In addition, the emission layer may further include a dopant material. Examples of the dopant material 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, periflanthene and the like 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 aryl group, silyl group, alkyl group, cycloalkyl group, and arylamino group are substituted or unsubstituted. Specifically, there are styrylamine, styryldiamine, styryltriamine, and styryltetraamine, but are not limited thereto. In addition, examples of the metal complex include, but are not limited to, an iridium complex and a platinum complex.

Electron transport layer

The electron transport layer refers to a layer formed between the light emitting layer and the cathode to receive electrons from the electron injection layer and transport electrons to the light emitting layer. In particular, in the present invention, a second compound having an energy level of 2.4 eV to 2.8 eV is used as an electron transport material.

The second compound is represented by the following formula (2):

[Formula 2]

In Chemical Formula 2,

L ₃ to L ₅ are each independently a single bond; Or a substituted or unsubstituted C _6-60 arylene,

k is 0, 1, or 2,

Ar ₃ and Ar ₄ are each independently phenyl unsubstituted or substituted with cyano; Biphenylyl unsubstituted or substituted with cyano; Or terphenylyl unsubstituted or substituted with cyano, but at least one of _{Ar 3} and Ar _{4 is phenyl substituted with cyano;} Biphenylyl substituted with cyano; Or terphenylyl substituted with cyano,

A is a monovalent substituent of the compound represented by the following formula (3),

[Formula 3]

In Chemical Formula 3,

T _{1 is a C 6-20} aromatic ring fused with a neighboring pentagonal ring,

,

,

, 또는

이고,X ₁ is

,

,

, or

ego,

W ₁ is a single bond, O, S, CR ₅ R ₆ , SiR ₇ R ₈ , or NR ₁₀ ,

Z ₁ and Z ₂ are each independently hydrogen; heavy hydrogen; Substituted or unsubstituted C _1-60 alkyl,

R ₁ to R ₈ are each independently hydrogen; heavy hydrogen; Substituted or unsubstituted C _6-60 aryl; _{Or a substituted or unsubstituted C 2-60} heteroaryl containing one or more heteroatoms selected from the group consisting of N, O and S _{, or a C 6-60} spiro ring by bonding of adjacent substituents to each other; Or can form a _{C 6-60 aromatic ring,}

R ₁₀ is bonded to each other with an adjacent substituent R ₃ to form _{a C 2-60 heteroaromatic ring containing at least one N atom,}

a1 to a4 are each independently an integer of 0 to 4,

When a1 to a4 are each 2 or more, the structures in the two or more parentheses are the same as or different from each other.

In addition, in the definition of a substituent in the present specification, the term "substituted with cyano" means that at least one hydrogen, preferably one or two hydrogens, among the hydrogens included in the substituent has been substituted with a cyano group.

In Formula 3, L ₃ to L ₅ may each independently be a single bond, or C _6-20 arylene.

Specifically, L ₃ to L ₅ may each independently be a single bond, phenylene, biphenylylene, or naphthylene.

More specifically, L ₃ and L ₄ may be a single bond, and L ₅ may be a single bond, phenylene, biphenylylene, or naphthylene.

In addition, Ar ₃ and Ar ₄ are both phenyl substituted with cyano, biphenylyl substituted with cyano, or terphenylyl substituted with cyano, or

One of Ar ₃ and Ar ₄ may be phenyl substituted with cyano, biphenylyl substituted with cyano, or terphenylyl substituted with cyano, and the rest may be phenyl, biphenylyl, or terphenylyl.

Specifically, Ar ₃ is phenyl substituted with 1 cyano, biphenylyl substituted with 1 cyano, or terphenylyl substituted with 1 cyano,

Ar ₄ can be phenyl, biphenylyl, or terphenylyl.

In addition, R ₁ to R ₈ are each independently hydrogen; heavy hydrogen; C _6-20 aryl; _{Or C 2-20} heteroaryl containing one or more heteroatoms selected from the group consisting of N, O and S; Alternatively, R ₅ and R ₆ may be bonded to each other to form a fluorene and a spiro ring. In this case, forming a spiro structure means having a structure in which one carbon is connected by a contact point.

Further, R ₁₀ may be bonded to each other with an adjacent substituent R ₃ to form an indole or carbazole ring.

The substituent A may be represented by the following formulas 3-1 to 3-9, depending on the structure of _{X 1:}

In Formulas 3-1 to 3-9,

Z ₁ and Z ₂ are each independently C _1-4 alkyl,

T ₁ is a benzene, naphthalene, or phenanthrene ring fused with a neighboring pentagonal ring,

W ₁ is a single bond, O, S, or NR ₁₀ ,

Here, R ₁₀ is bonded to each other with an adjacent substituent R ₃ to form an indole or carbazole ring,

R ₁ to R ₄ , R ₁₁ and R ₁₂ are each independently hydrogen, deuterium, or C _6-20 aryl,

a1 to a6 are each independently 0, 1, 2, or 3,

* Represents a position connected to _{L 5 in} Formula 2.

Specifically, in Formula 3-1, Z ₁ and Z ₂ may be methyl.

In addition, in Formulas 3-1 to 3-9, R ₁ to R ₄ , R ₁₁ and R ₁₂ may be hydrogen or deuterium.

In addition, specifically, the second compound may be represented by any one of the following Formulas 2A to 2I:

[Formula 2A]

[Formula 2B]

[Formula 2C]

[Formula 2D]

[Formula 2E]

[Formula 2F]

[Chemical Formula 2G]

[Formula 2H]

[Formula 2I]

In Formulas 2A to 2I,

T ₁ is a benzene, naphthalene, or phenanthrene ring fused with a neighboring pentagonal ring

W ₂ is a single bond, O, or S,

R ₁ to R ₄ , R ₁₁ and R ₁₂ are each independently hydrogen, deuterium, or C _6-20 aryl,

a1 to a6 are each independently 0, 1, 2, or 3,

L ₃ to L ₅ , k, Ar ₃ and Ar ₄ are as defined in Chemical Formula 2.

For example, A may be any one selected from the group consisting of the following formulas 3a to 3k:

In Formulas 3a to 3k,

W ₂ is a single bond, O, or S,

* Represents a position connected to _{L 5 in} Formula 2.

Specifically, for example, A may be any one selected from the group consisting of:

In the above, * represents a position connected to _{L 5 in Formula 2.}

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

The second compound represented by Chemical Formula 2 may be prepared by a manufacturing method as shown in Scheme 2 below, for example.

[Scheme 2]

In Reaction Scheme 2, _{descriptions of L 3} to L ₅ , Ar ₃ , Ar ₄ and A are as defined in Chemical Formula 3, and Y is halogen, preferably bromo or chloro. The reaction is a Suzuki coupling reaction, preferably carried out in the presence of a palladium catalyst, and the reactor for the Suzuki coupling reaction can be changed as known in the art. The manufacturing method may be more specific in the manufacturing examples to be described later.

In addition, the electron transport layer may further include a metal complex compound other than the second compound. Meanwhile, the metal complex compound refers to a complex of a metal selected from the group consisting of alkali metals, alkaline earth metals, transition metals, and metals of Group 13 in the periodic table.

Specifically, the metal complex compound may be represented by the following Chemical Formula 4, wherein M is a central metal, L ₁₁ is a main ligand, and L ₁₂ is an auxiliary ligand.

[Formula 4]

M(L ₁₁ ) _n1 (L ₁₂ ) _n12

In Chemical Formula 4,

M is lithium, beryllium, manganese, copper, zinc, aluminum, or gallium,

L ₁₁ is substituted or unsubstituted 8-hydroxyquinolinato; Or substituted or unsubstituted 10-hydroxybenzo[h]quinolinato,

L ₁₂ is halogen; Substituted or unsubstituted phenolato; Or a substituted or unsubstituted naphtholato,

n11 is 1, 2, or 3,

n12 is 0 or 1,

n11+n12 is 1, 2, or 3,

When n11 is 2 or more, 2 or more L ₁₁ are the same as or different from each other.

More specifically, L ₁₁ is halogen, or 8-hydroxyquinolinato unsubstituted or substituted with _{C 1-4 alkyl;} Or halogen or C _1-4 alkyl substituted or unsubstituted 10-hydroxybenzo[h]quinolinato,

L ₁₂ is halogen; _Phenolato unsubstituted or substituted with C 1-4 alkyl; It may be unsubstituted or substituted with _{C 1-4 alkyl naphtholato.}

Or, L ₁₁ is 8-hydroxyquinolinato, 2-methyl-8-hydroxyquinolinato, or 10-hydroxybenzo[h]quinolinato,

L ₁₂ may be chloro, o-cresolato, or 2-naphtholato.

For example, the metal complex compound is 8-hydroxyquinolinato lithium, bis(8-hydroxyquinolinato)zinc, bis(8-hydroxyquinolinato)copper, bis(8-hydroxyquinolinato) To) manganese, tris (8-hydroxyquinolinato) aluminum, tris (2-methyl-8-hydroxyquinolinato) aluminum, tris (8-hydroxyquinolinato) gallium, bis (10-hydroxy) Benzo[h]quinolinato)beryllium, bis(10-hydroxybenzo[h]quinolinato)zinc, bis(2-methyl-8-quinolinato)chlorogallium, bis(2-methyl-8-qui Nolinato)(o-cresolato)gallium, bis(2-methyl-8-quinolinato)(1-naphtolato)aluminum and bis(2-methyl-8-quinolinato)(2-naphtolato)gallium It is selected from the group consisting of.

Such a metal complex compound can be prepared by a conventional method known in the art.

In addition, the electron transport layer preferably includes the compound represented by Chemical Formula 2 and the metal complex compound in a weight ratio of 3:7 to 7:3. Specifically, for example, the electron transport layer may include the compound represented by Formula 1 and the metal complex compound in a weight ratio of 3:7, 4:6, 5:5, 6:4, or 7:3. .

Electron injection layer

The organic light-emitting device according to the present invention may further include an electron injection layer, which is a layer for injecting electrons from an electrode on the electron transport layer. As the electron injecting material, a compound having an ability to transport electrons, having an electron injecting effect from the cathode, an excellent electron injecting effect for a light emitting layer or a light emitting material, and excellent in thin film forming ability is preferable. In addition, the electron injection layer may also serve as the above-described electron transport layer.

Specific examples of the electron injection material include LiF, NaCl, CsF, Li ₂ O, BaO, fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, Derivatives thereof, such as perylene tetracarboxylic acid, preorenylidene methane, and anthrone, metal complex compounds, and nitrogen-containing 5-membered ring derivatives, but are not limited thereto.

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 light-emitting layer 3, an electron transport layer 4, and a cathode 5. In such a structure, the compound represented by Formula 1 may be included in the emission layer, and the compound represented by Formula 2 may be included in the electron transport layer.

2 shows a substrate 1, an anode 2, a hole injection layer 6, a hole transport layer 7, a light emitting layer 3, an electron transport layer 4, an electron injection layer 8 and a cathode 5 It shows an example of an organic light emitting device. In such a structure, the compound represented by Formula 1 may be included in the emission layer, and the compound represented by Formula 2 may be included in the electron transport layer. In this case, the electron transport layer and the electron injection layer may be provided as one layer such as an electron injection and transport layer.

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.

The fabrication of the organic light emitting device will be described in detail in the following examples. However, the following examples are for illustrating the present invention, and the scope of the present invention is not limited thereto.

Preparation Example 1: Preparation of compound 1-1

10 g (1 equivalent) of compound A1-1 and 6.5 g (1 equivalent) of compound B1-1 were added to tetrahydrofuran (150 mL). After adding 2M K ₂ CO ₃ (100 mL), tris(dibenzylideneacetone)dipalladium(0)(Pd(dba) ₂ , 0.6 g), and tetracyclohexylphosphine (PCy _3, 0.6 g) , Stirred and refluxed for 5 hours. After cooling to room temperature, the resulting solid was filtered and recrystallized with chloroform and ethanol to prepare 8.6 g (yield 65%) of compound 1-1.

MS:[M+H] ⁺ = 507

Preparation Example 2: Preparation of compound 1-2

10 g (1 equivalent) of Compound A1-2 and 7.5 g (1 equivalent) of Compound B1-2 were added to tetrahydrofuran (150 mL). After adding 2M K ₂ CO ₃ (100 mL), tris(dibenzylideneacetone)dipalladium(0)(Pd(dba) ₂ , 0.6 g), and tetracyclohexylphosphine (PCy _3, 0.6 g) , Stirred and refluxed for 5 hours. After cooling to room temperature, the resulting solid was filtered and recrystallized with chloroform and ethanol to prepare 9.7 g (yield 71%) of the compound 1-2.

MS:[M+H] ⁺ = 457

Preparation Example 3: Preparation of compound 1-3

10 g (1 equivalent) of compound A1-1 and 4.5 g (1 equivalent) of compound B1-3 were added to tetrahydrofuran (150 mL). After adding 2M K ₂ CO ₃ (100 mL), tris(dibenzylideneacetone)dipalladium(0)(Pd(dba) ₂ , 0.6 g), and tetracyclohexylphosphine (PCy _3, 0.6 g) , Stirred and refluxed for 5 hours. After cooling to room temperature, the resulting solid was filtered and recrystallized with chloroform and ethanol to prepare 10.2 g (yield 74%) of the compound 1-3.

MS:[M+H] ⁺ = 431

Preparation Example 4: Preparation of compound 2-1

10 g (1 equivalent) of compound A2-1 and 12.0 g (1 equivalent) of compound B2-1 were added to tetrahydrofuran (150 mL). After adding 2M K ₂ CO ₃ (100 mL), tris(dibenzylideneacetone)dipalladium(0)(Pd(dba) ₂ , 0.6 g), and tetracyclohexylphosphine (PCy _3, 0.6 g) , Stirred and refluxed for 5 hours. After cooling to room temperature, the resulting solid was filtered and recrystallized with chloroform and ethanol to prepare 13.6 g of compound 2-1 (yield 77%).

MS:[M+H] ⁺ = 651

Preparation Example 5: Preparation of compound 2-2

10 g (1 equivalent) of compound A2-2 and 13.0 g (1 equivalent) of compound B2-2 were added to tetrahydrofuran (150 mL). 2M K ₂ CO ₃ (100 mL), Pd(dba) ₂ (0.5 g), and PCy ₃ (0.5 g) were added, followed by stirring and refluxing for 5 hours. After cooling to room temperature, the resulting solid was filtered and recrystallized with chloroform and ethanol to prepare 15.8 g of Compound 2-2 (yield 71%).

MS:[M+H] ⁺ = 687

Preparation Example 6: Preparation of compound 2-3

10 g (1 equivalent) of Compound A2-1 and 12.4 g (1 equivalent) of Compound B2-3 were added to tetrahydrofuran (150 mL). 2M K ₂ CO ₃ (100 mL), Pd(dba) ₂ (0.6 g), and PCy ₃ (0.6 g) were added, followed by stirring and refluxing for 5 hours. After cooling to room temperature, the resulting solid was filtered and recrystallized with chloroform and ethanol to prepare 16.2 g of Compound 2-3 (yield 90%).

MS:[M+H] ⁺ = 665

Preparation Example 7: Preparation of compound 2-4

10 g (1 equivalent) of compound A2-2 and 12.4 g (1 equivalent) of compound B2-3 were added to tetrahydrofuran (150 mL). 2M K ₂ CO ₃ (100 mL), Pd(dba) ₂ (0.6 g), and PCy ₃ (0.6 g) were added, followed by stirring and refluxing for 5 hours. After cooling to room temperature, the resulting solid was filtered and recrystallized with chloroform and ethanol to prepare 14.8 g of compound 2-4 (yield 82%).

MS:[M+H] ⁺ = 665

Preparation Example 8: Preparation of compound 2-5

10 g (1 equivalent) of compound A2-1 and 12.4 g (1 equivalent) of compound B2-4 were added to tetrahydrofuran (150 mL). 2M K ₂ CO ₃ (100 mL), Pd(dba) ₂ (0.5 g), and PCy ₃ (0.5 g) were added, followed by stirring and refluxing for 5 hours. After cooling to room temperature, the resulting solid was filtered and recrystallized with chloroform and ethanol to prepare 15.9 g of compound 2-5, yield 88%).

MS:[M+H] ⁺ = 665

Preparation Example 9: Preparation of compound 2-6

10 g (1 equivalent) of compound A2-3 and 8.8 g (1 equivalent) of compound B2-3 were added to tetrahydrofuran (150 mL). 2M K ₂ CO ₃ (100 mL), Pd(dba) ₂ (0.6 g), and PCy ₃ (0.6 g) were added, followed by stirring and refluxing for 5 hours. After cooling to room temperature, the resulting solid was filtered and recrystallized with chloroform and ethanol to prepare 11.2 g of compound 2-6 (yield 79%).

MS:[M+H] ⁺ = 741

Example 1

A glass substrate (corning 7059 glass) coated with a thin film of ITO (indium tin oxide) having a thickness of 1000 Å was placed in distilled water containing a dispersant and washed with ultrasonic waves. The detergent was manufactured by Fischer Co., and the distilled water was Millipore Co. Distilled water filtered secondarily with the product's filter was used. After washing the ITO for 30 minutes, ultrasonic washing was performed for 10 minutes by repeating twice with distilled water. After washing with distilled water, ultrasonic washing was performed in the order of isopropyl alcohol, acetone, and methanol, followed by drying.

On the prepared ITO transparent electrode, hexanitrile hexaazatriphenylene (HATCN) was thermally vacuum deposited to a thickness of 500 Å to form a hole injection layer. HT1 (400 Å), which is a material for transporting holes, was vacuum deposited thereon to form a hole transport layer.

The host compound 1-1 prepared in Preparation Example 1 and the dopant compound BD1 were vacuum-deposited at a weight ratio of 25:1 as a host of the emission layer on the hole transport layer to form an emission layer having a thickness of 300 Å.

Compound 2-1 prepared in Preparation Example 4 and LiQ (8-Hydroxyquinolinato) lithium) were vacuum-deposited at a weight ratio of 5:5 on the emission layer to form an electron transport layer with a thickness of 310Å.

Lithium fluoride (LiF) at a thickness of 12 Å and aluminum at a thickness of 2,000 Å were sequentially deposited on the electron transport layer to form an electron injection layer and a cathode, thereby manufacturing an organic light emitting device.

In the above process, the deposition rate of organic materials was maintained at 0.4 to 0.7 Å/sec, the deposition rate of lithium fluoride at the cathode was 0.3 Å/sec, and the deposition rate of aluminum was 2 Å/sec, and the vacuum degree during deposition was 2 x10 ^-7 By maintaining ~ 5 x10 ^-6 torr, an organic light emitting device was manufactured.

Examples 2 to 18 and Comparative Examples 1 to 4

In Example 1, except that the compound shown in Table 1 was used instead of the host material 1-1, and the compound shown in Table 1 was used instead of the compound 2-1 as the electron transport layer material, An organic light-emitting device was manufactured in the same manner.

At this time, the structures of the compounds used in Comparative Examples 1 to 4 are as follows.

Experimental example

For the organic light emitting device prepared in the above Examples and Comparative Examples, the driving voltage and luminous efficiency at a current density of ^{10 mA/cm 2} , and a time to become 98% of the initial luminance at a current density of ^{20 mA/cm 2 (LT98} ) Was measured, and the results are shown in Table 1 below. In addition, the LUMO energy level value of each compound was also described.

Host Electron transport layer OLED characteristics compound LUMO
(eV) compound LUMO
(eV) Voltage
(V) Current efficiency
(cd/A) Life Time 98 at 20mA/cm ² Example 1 Compound 1-1 2.82 Compound 2-1 2.76 3.70 5.40 60 Example 2 Compound 1-1 2.82 Compound 2-2 2.78 3.68 5.38 63 Example 3 Compound 1-1 2.82 Compound 2-3 2.78 3.69 5.39 62 Example 4 Compound 1-1 2.82 Compound 2-4 2.76 3.72 5.42 61 Example 5 Compound 1-1 2.82 Compound 2-5 2.58 3.67 5.52 58 Example 6 Compound 1-1 2.82 Compound 2-6 2.72 3.66 5.38 59 Example 7 Compound 1-2 2.71 Compound 2-1 2.76 3.60 5.48 57 Example 8 Compound 1-2 2.71 Compound 2-2 2.78 3.62 5.50 56 Example 9 Compound 1-2 2.71 Compound 2-3 2.78 3.58 5.48 58 Example 10 Compound 1-2 2.71 Compound 2-4 2.76 3.61 5.51 57 Example 11 Compound 1-2 2.71 Compound 2-5 2.58 3.63 5.47 55 Example 12 Compound 1-2 2.71 Compound 2-6 2.72 3.59 5.53 53 Example 13 Compound 1-3 2.72 Compound 2-1 2.76 3.63 5.48 58 Example 14 Compound 1-3 2.72 Compound 2-2 2.78 3.66 5.50 56 Example 15 Compound 1-3 2.72 Compound 2-3 2.78 3.69 5.51 57 Example 16 Compound 1-3 2.72 Compound 2-4 2.76 3.62 5.49 59 Example 17 Compound 1-3 2.72 Compound 2-5 2.58 3.60 5.56 55 Example 18 Compound 1-3 2.72 Compound 2-6 2.72 3.59 5.55 57 Comparative Example 1 Compound 1-1 2.82 ET-01 2.67 4.10 4.68 35 Comparative Example 2 Compound 1-1 2.82 ET-02 2.75 4.12 4.63 32 Comparative Example 3 Compound 1-3 2.72 ET-03 2.70 4.04 4.70 30 Comparative Example 4 Compound 1-3 2.72 ET-04 2.71 4.03 4.71 28

As shown in Table 1, the organic light emitting device of the embodiment in which the compound represented by Formula 1 is used as a host of the emission layer and the compound represented by Formula 2 is used as an electron transport layer material at the same time is represented by Formulas 1 and 2. It can be seen that compared to the organic light-emitting device of Comparative Example employing only one of the compounds, excellent characteristics are exhibited in all aspects of driving voltage, luminous efficiency, and lifetime. Considering that the luminous efficiency and lifetime characteristics of the organic light-emitting device generally have a trade-off relationship with each other, the organic light-emitting device employing a combination of the compounds of the present invention has significantly improved device characteristics compared to the comparative example device. Means to represent.

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

Claims (12)

anode; Light-emitting layer; Electron transport layer; And a cathode,
The emission layer includes a first compound having a Lowest unoccupied molecular orbital (LUMO) energy level of 2.6 eV to 3.0 eV,
The electron transport layer includes a second compound having a Lowest unoccupied molecular orbital (LUMO) energy level of 2.4 eV to 2.8 eV,
The second compound is represented by the following formula (2),
Organic Light-Emitting Element:
[Formula 2]

In Chemical Formula 2,
L ₃ to L ₅ are each independently a single bond; Or a substituted or unsubstituted C _6-60 arylene,
k is 0, 1, or 2,
Ar ₃ and Ar ₄ are each independently phenyl unsubstituted or substituted with cyano; Biphenylyl unsubstituted or substituted with cyano; Or terphenylyl unsubstituted or substituted with cyano, but at least one of _{Ar 3} and Ar _{4 is phenyl substituted with cyano;} Biphenylyl substituted with cyano; Or terphenylyl substituted with cyano,
A is a monovalent substituent of the compound represented by the following formula (3),
[Formula 3]

In Chemical Formula 3,
T _{1 is a C 6-20} aromatic ring fused with a neighboring pentagonal ring,
X ₁ is

ego,
W ₁ is O or S,
R ₁ to R ₄ are Each independently, hydrogen; heavy hydrogen; Substituted or unsubstituted C _6-60 aryl; _{Or substituted or unsubstituted C 2-60} heteroaryl containing one or more heteroatoms selected from the group consisting of N, O and S,
a1 to a4 are each independently an integer of 0 to 4,
When a1 to a4 are each 2 or more, the structures in the two or more parentheses are the same as or different from each other.
The method of claim 1,
The first compound is represented by the following formula (1),
Organic Light-Emitting Element:
[Formula 1]

In Formula 1,
L ₁ and L ₂ are each independently a single bond; Or a substituted or unsubstituted C _6-60 arylene,
Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted C _6-60 aryl,
Q ₁ and Q ₂ are each independently hydrogen; heavy hydrogen; halogen; Cyano; Nitro; Amino; Substituted or unsubstituted C _1-60 alkyl; C _1-60 haloalkyl; Substituted or unsubstituted C _1-60 haloalkoxy; Substituted or unsubstituted C _3-60 cycloalkyl; Substituted or unsubstituted C _2-60 alkenyl; Substituted or unsubstituted C _6-60 aryl; _{Or a substituted or unsubstituted C 2-60} heteroaryl including at least one of O, N, Si and S,
n1 and n2 are each independently an integer of 0 to 4,
When n1 and n2 are each 2 or more, the structures in the two or more parentheses are the same as or different from each other.
The method of claim 2,
L ₁ and L ₂ are each independently a single bond, phenylene, naphthylene, or anthracenylene,
Organic light emitting device.
The method of claim 2,
Ar ₁ and Ar ₂ are each independently, unsubstituted, or C _1-4 alkyl; _{Or a C 6-10} aryl substituted with tri(C _1-4 alkyl)silyl,
Organic light emitting device.
The method of claim 2,
Q ₁ and Q ₂ are both hydrogen,
Organic light emitting device.
The method of claim 2,
The first compound is any one selected from the group consisting of,
Organic Light-Emitting Element:

.
The method of claim 1,
The second compound is represented by any one of the following formulas 2D and 2H,
Organic Light-Emitting Element:
[Formula 2D]

[Formula 2H]

In Formulas 2D and 2H,
W ₂ is O or S,
R ₁ to R ₄ are each independently hydrogen, deuterium, or C _6-20 aryl,
a1 to a4 are each independently 0, 1, 2, or 3,
L ₃ to L ₅ , k, Ar ₃ and Ar ₄ are as defined in claim 1.
The method of claim 1,
L ₃ to L ₅ are each independently a single bond, phenylene, biphenylylene, or naphthylene,
Organic light emitting device.
The method of claim 1,
Ar ₃ is phenyl substituted with 1 cyano, biphenylyl substituted with 1 cyano, or terphenylyl substituted with 1 cyano,
Ar ₄ is phenyl, biphenylyl, or terphenylyl,
Organic light emitting device.
The method of claim 1,
A is any one selected from the group consisting of the following formula 3d and dj,
Organic Light-Emitting Element:

In the above formulas 3d and dj,
W ₂ is O or S,
* Represents a position connected to _{L 5 in} Formula 2.
The method of claim 1,
A is any one selected from the group consisting of,
Organic Light-Emitting Element:

In the above, * represents a position connected to _{L 5 in Formula 2.}
The method of claim 1,
The second compound is any one selected from the group consisting of,
Organic Light-Emitting Element:

.

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