KR20220013869A - Organic light emitting device - Google Patents

Abstract

The present invention provides an organic light emitting device. According to the present invention, an organic light emitting device includes: an anode; a cathode; and a light emitting layer between the anode and the cathode. The light emitting layer includes a compound represented by the following chemical formula 1 and a compound represented by the following chemical formula 2. It is possible to improve the driving voltage, efficiency, and lifespan of the organic light emitting device.

Description

Organic light emitting device

The present invention relates to an organic light emitting device.

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

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

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

Meanwhile, in recent years, organic light emitting devices using a solution process, particularly an inkjet process, have been developed instead of the conventional deposition process in order to reduce process costs. In the early days, all organic light emitting device layers were coated with a solution process to develop an organic light emitting device, but the current technology has limitations, so only HIL, HTL, and EML are processed as a solution process, and the subsequent process is a hybrid that utilizes the existing deposition process. (hybrid) process is being studied.

Accordingly, the present invention provides a novel material for an organic light emitting device that can be used in an organic light emitting device and at the same time can be used in a solution process, and an organic light emitting device using the same.

Korean Patent Publication No. 10-2000-0051826

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

The present invention provides the following organic light emitting device:

anode; cathode; and 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 device:

[Formula 1]

In Formula 1,

Y ₁ and Y ₂ are each independently O, S, Se, Te, or NR';

R' is each independently hydrogen; substituted or unsubstituted C _1-60 alkyl; substituted or unsubstituted C _6-60 aryl; Or substituted or unsubstituted C _2-60 heteroaryl containing any one or more heteroatoms selected from the group consisting of N, O and S,

L ₁ and L ₂ are each independently, a single bond; substituted or unsubstituted C _6-60 arylene; Or substituted or unsubstituted C _2-60 heteroarylene containing any one or more heteroatoms selected from the group consisting of N, O and S,

Ar ₁ to Ar ₄ are each independently, substituted or unsubstituted C _6-60 aryl; Or substituted or unsubstituted C _2-60 heteroaryl containing any one or more heteroatoms selected from the group consisting of N, O and S,

[Formula 2]

In Formula 2,

Ar ₁₁ is C _6-60 aryl substituted with one or more deuterium; Or C _2-60 heteroaryl comprising any one or more heteroatoms selected from the group consisting of N, O and S substituted with one or more deuterium;

Ar ₁₂ is C _6-60 aryl substituted with one or more deuterium; Or C _2-60 heteroaryl comprising any one or more heteroatoms selected from the group consisting of N, O and S substituted with one or more deuterium;

R ₁₁ is deuterium,

z is an integer from 0 to 8;

In the organic light emitting diode according to the present invention, the light emitting layer can be manufactured by a solution process, and the efficiency, low driving voltage and/or lifespan characteristics of the organic light emitting diode can be improved.

1 shows an example of an organic light emitting device including a substrate 1 , an anode 2 , a light emitting layer 3 , and a cathode 4 .
2 shows a substrate 1, an anode 2, a hole injection layer 5, a hole transport layer 6, a light emitting layer 3, an electron transport layer 7, an electron injection layer 8 and a cathode 4 It shows an example of the organic light emitting device made up.

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

(Definition of Terms)

또는

는 다른 치환기에 연결되는 결합을 의미한다.In this specification,

or

means a bond connected to another substituent.

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

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

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

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

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

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

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

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

In the present specification, the alkenyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 2 to 40. According to an exemplary embodiment, the carbon number of the alkenyl group is 2 to 20. According to another exemplary embodiment, the carbon number of the alkenyl group is 2 to 10. According to another exemplary embodiment, the alkenyl group has 2 to 6 carbon atoms. Specific examples include vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1- Butenyl, 1,3-butadienyl, 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 carbon number of the cycloalkyl group is 3 to 20. According to another exemplary embodiment, the cycloalkyl group has 3 to 6 carbon atoms. Specifically, cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3, 4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, and the like, but is not limited thereto.

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

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

In the present specification, heteroaryl is a heteroaryl containing at least one of O, N, Si and S as a heterogeneous element, and the number of carbon atoms is not particularly limited, but is preferably from 2 to 60 carbon atoms. Examples of heteroaryl include xanthene, thioxanthen, thiophene, furan, pyrrole, imidazole, thiazole, oxazole, oxadiazole, triazole, pyridyl, bipyridyl, 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 ( phenanthroline), an isoxazolyl group, a thiadiazolyl group, a phenothiazinyl group, and a dibenzofuranyl group, but are not limited thereto.

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

(Anode and Cathode)

The organic light emitting device according to the present invention includes an anode and a cathode.

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

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

(hole injection layer)

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

The hole injection layer is a layer for injecting holes from the electrode, and as a hole injection material, it has the ability to transport holes, so it has a hole injection effect at the anode, an excellent hole injection effect on the light emitting layer or the light emitting material, and is produced in the light emitting layer A compound which prevents the movement of excitons to the electron injection layer or the electron injection material and is excellent in the ability to form a thin film is preferable. It is preferable that the highest occupied molecular orbital (HOMO) of the hole injection material is between the work function of the positive electrode material and the HOMO of the surrounding organic material layer. Specific examples of the hole injection material include metal porphyrin, oligothiophene, arylamine-based organic material, hexanitrile hexaazatriphenylene-based organic material, quinacridone-based organic material, and perylene-based organic material. of organic substances, anthraquinones, and conductive polymers of polyaniline and polythiophene series, but are not limited thereto.

(hole transport layer)

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

The hole transport layer is a layer that receives holes from the hole injection layer and transports them to the light emitting layer. A material capable of transporting holes from the anode or hole injection layer to the light emitting layer as a hole transport material. A material with high hole mobility. This is suitable. Specific examples include, but are not limited to, an arylamine-based organic material, a conductive polymer, and a block copolymer having a conjugated portion and a non-conjugated portion together.

(Light emitting layer)

The light emitting layer of the organic light emitting device according to the present invention includes a host and a dopant, and in particular, includes the compound represented by Formula 1 as a dopant and the compound represented by Formula 2 as a host.

Preferably, in Formula 1, Y ₁ and Y ₂ are each independently O, S, or NR', and R' is each independently, methyl; phenyl; phenyl substituted with 5 deuterium; or t-butylphenyl. Preferably, Y ₁ and Y ₂ may be the same as each other. Preferably, Y ₁ and Y ₂ are both O.

Preferably, L ₁ and L ₂ are each independently a single bond; unsubstituted phenylene; phenylene substituted with 1 or 2 C _1-10 alkyl; phenylene substituted with 1 to 2 halogens; phenylene substituted with 4 deuterium; pyrimidinediyl; tetrazindiyl; or thiophenediyl. Preferably, L ₁ and L ₂ are each independently a single bond; phenylene; dimethylphenylene; fluorophenylene; difluorophenylene; phenylene substituted with 4 deuterium; pyrimidinediyl; tetrazindiyl; or thiophenediyl. In one embodiment, L ₁ and L ₂ may be the same as each other.

Preferably, Ar ₁ to Ar ₄ are each independently, substituted or unsubstituted C _6-20 aryl; or C _2-20 heteroaryl including any one or more heteroatoms selected from the group consisting of substituted or unsubstituted N, O and S.

Preferably, Ar ₁ to Ar ₄ are each independently any one selected from the group consisting of:

above,

n and m are each independently an integer of 0 to 2,

R'' is each independently C _1-10 alkyl,

Ar'' is each independently C _2-10 heteroaryl including any one or more heteroatoms selected from the group consisting of N, O and S;

X is C(R _a- )(R _b ), O or S;

R _a and R _b are each independently hydrogen or C _1-10 alkyl.

Preferably, Ar ₁ to Ar ₄ are each independently any one selected from the group consisting of:

In one embodiment, Ar ₁ and Ar ₃ may be the same as each other, and Ar ₂ and Ar ₄ may be the same substituents.

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

The compound represented by Formula 1 may be prepared according to a preparation method such as Scheme 1 and/or Scheme 2 below. Specifically, when L ₁ and L ₂ are a bond, the compound represented by Formula 1 may be prepared by a preparation method as shown in Scheme 1 below, and when L ₁ and L ₂ of Formula 1 are not a bond, the compound represented by Formula 1 is The compound represented can be prepared by a preparation method as in Scheme 2:

[Scheme 1]

[Scheme 2]

In Schemes 1 and 2, definitions other than X' are the same as defined above, and X' is halogen, preferably chloro or bromo.

Scheme 1 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 can be changed as known in the art.

The Suzuki coupling reaction in Scheme 2 is 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.

The manufacturing method may be more specific in Preparation Examples to be described later.

In Formula 2, preferably, Ar ₁₁ is naphthyl substituted with one or more deuterium, or naphthylphenyl substituted with one or more deuterium. In this case, the naphthyl may be substituted with 1 to 7 deuterium, and the naphthylphenyl may be substituted with 1 to 11 deuterium.

Preferably, Ar ₁₂ is naphthylphenyl substituted with one or more deuterium, or dibenzofuranyl substituted with one or more deuterium. In this case, the naphthylphenyl may be substituted with 1 to 11 deuterium, and dibenzofuranyl may be substituted with 1 to 7 deuterium.

Preferably, the deuterium substitution rate of Formula 2 is 60 to 100%. The 'deuterium substitution rate' refers to the number of substituted deuterium relative to the total number of hydrogens that may exist in Formula 2 above. Preferably, the deuterium substitution rate of Formula 2 is 65% or more, 70% or more, 75% or more, 80% or more, 85% or more, 90% or more, 99% or less, 98% or less, 97% or more. or less, 96% or less, 95% or less, 94% or less, 93% or less, or 92% or less.

Preferably, Formula 2 is represented by any one of Formulas 2-1 to 2-4 below:

[Formula 2-1]

In Formula 2-1,

o+p+q+r is an integer from 21 to 23,

[Formula 2-2]

In Formula 2-2,

o+p+q+r is an integer from 21 to 23,

[Formula 2-3]

In Formula 2-3,

s+p+r is an integer of 14 to 22, preferably an integer of 21 to 22;

[Formula 2-4]

In Formula 2-4,

s+p+q+r is an integer of 20-26, Preferably it is an integer of 23-24.

Meanwhile, the compound represented by Formula 2 may be prepared by treating the deuterated compound represented by Formula 2 with a deuterated solvent, such as benzene-D6, in the presence of an H/D exchange catalyst. The manufacturing method may be more specific in Preparation Examples to be described later.

In addition, in the light emitting layer according to the present invention, the weight ratio of the compound represented by Formula 1 to the compound represented by Formula 2 is preferably 1 to 10: 99 to 90.

(electron transport layer)

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

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

(electron injection layer)

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

The electron injection layer is a layer that injects electrons from the electrode, has the ability to transport electrons, has an electron injection effect from the cathode, an excellent electron injection effect on the light emitting layer or the light emitting material, and hole injection of excitons generated in the light emitting layer. A compound which prevents movement to a layer and is excellent in the ability to form a thin film is preferable. Specifically, fluorenone, anthraquinodimethane, diphenoquinone, thiopyran dioxide, oxazole, oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, preorenylidene methane, anthrone, etc., derivatives thereof, metals complex compounds and nitrogen-containing 5-membered ring derivatives, but are not limited thereto.

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

(organic light emitting element)

The organic light emitting device according to the present invention may be a normal type organic light emitting device in which an anode, one or more organic material layers, and a cathode are sequentially stacked on a substrate. Also, the organic light emitting device according to the present invention may be an inverted type organic light emitting device in which a cathode, one or more organic material layers, and an anode are sequentially stacked on a substrate. For example, the structure of the organic light emitting diode according to an embodiment of the present invention is illustrated in FIGS. 1 and 2 .

1 shows an example of an organic light emitting device including a substrate 1 , an anode 2 , a light emitting layer 3 , and a cathode 4 . In such a structure, the light emitting layer includes the compound represented by Formula 1 and the compound represented by Formula 2 above.

2 shows a substrate 1, an anode 2, a hole injection layer 5, a hole transport layer 6, a light emitting layer 3, an electron transport layer 7, an electron injection layer 8, and a cathode 4 An example of an organic light emitting device is shown. In such a structure, the light emitting layer includes the compound represented by Formula 1 and the compound represented by Formula 2 above.

The organic light emitting diode according to the present invention may be manufactured using materials and methods known in the art, except for using the above-described materials.

For example, the organic light emitting device according to the present invention may be manufactured by sequentially stacking an anode, an organic material layer, and a cathode on a substrate. At this time, by using a PVD (physical vapor deposition) method such as sputtering or e-beam evaporation, a metal or a metal oxide having conductivity or an alloy thereof is deposited on a substrate to form an anode And, after forming an organic layer including a hole injection layer, a hole transport layer, a light emitting layer and an electron transport layer 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 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.

The organic light emitting device according to the present invention may be a top emission type, a back emission type, or a double side emission type depending on the material used.

(Coating composition)

Meanwhile, the light emitting layer according to the present invention may be formed by a solution process. To this end, the present invention provides a coating composition for forming a light emitting layer comprising the compound represented by the formula (1) and the compound represented by the formula (2).

The solvent is not particularly limited as long as it is a solvent capable of dissolving or dispersing the compound according to the present invention, and for example, chloroform, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, o - Chlorine solvents, such as dichlorobenzene; ether solvents such as tetrahydrofuran and dioxane; aromatic hydrocarbon solvents such as toluene, xylene, trimethylbenzene, and mesitylene; aliphatic hydrocarbon solvents such as cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; Ketone solvents, such as acetone, methyl ethyl ketone, and cyclohexanone; ester solvents such as ethyl acetate, butyl acetate, and ethyl cellosolve acetate; Polyvalents such as ethylene glycol, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, dimethoxyethane, propylene glycol, diethoxymethane, triethylene glycol monoethyl ether, glycerin, and 1,2-hexanediol alcohols and derivatives thereof; alcohol solvents such as methanol, ethanol, propanol, isopropanol and cyclohexanol; sulfoxide solvents such as dimethyl sulfoxide; and amide solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide; benzoate solvents such as butylbenzoate and methyl-2-methoxybenzoate; tetralin; and solvents such as 3-phenoxy-toluene. In addition, the above-mentioned solvents may be used alone or as a mixture of two or more solvents.

In addition, the viscosity of the coating composition is preferably 1 cP to 10 cP, and coating is easy in the above range. In addition, the concentration of the compound according to the present invention in the coating composition is preferably 0.1 wt/v% to 20 wt/v%, respectively.

In addition, the present invention provides a method of forming a light emitting layer using the above-described coating composition. Specifically, on the anode, coating the above-described coating composition for forming a light emitting layer in a solution process; and heat-treating the coated coating composition.

The solution process uses the coating composition according to the present invention described above, and refers to spin coating, dip coating, doctor blading, inkjet printing, screen printing, spraying method, roll coating, and the like, but is not limited thereto.

The heat treatment temperature in the heat treatment step is preferably 150 to 230 ℃. In addition, the heat treatment time is 1 minute to 3 hours, more preferably 10 minutes to 1 hour. In addition, the heat treatment is preferably performed in an inert gas atmosphere such as argon or nitrogen. In addition, the step of evaporating the solvent between the coating step and the heat treatment step may be further included.

The above-described manufacturing of the organic light emitting device according to the present invention will be described in detail in the following examples. However, the following examples are intended to illustrate the present invention, and the scope of the present invention is not limited thereto.

[Synthesis Example]

Synthesis Example 1: Preparation of compound BH1

(Synthesis Example 1-1)

9-Bromo-10-(1-naphthyl)anthracene (8 g, 21 mmol), 4-(2-naphthyl)phenylboronic acid (5.3 g, 21.5 mmol), potassium carbonate (6 g, 44 mmol) , Pd(Amphos) ₂ Cl ₂ (15 mg, 0.02 mmol), Aliquat 336 (0.2 g, 0.53 mmol) in a 250 mL round-bottom flask, dissolved in 100 mL toluene and 30 mL water, and then heated to 80 °C overnight stirred for a while. After completion of the reaction, the reactant was cooled to room temperature, diluted sufficiently in ethyl acetate, and washed with ethyl acetate/brine to separate the organic layer. Water was removed with magnesium sulfate and passed through a Celite-Florisil-Silica pad. The passed solution was concentrated under reduced pressure, and column purification was performed with hexane/ethyl acetate to obtain 9,8 g of compound X1.

(Synthesis Example 1-2)

Compound X1 (9.8 g, 19 mmol) was placed in a 250 mL round bottom flask under a nitrogen atmosphere and dissolved in benzene-D ₆ (244 g, 2.9 mol). Then, trifluoromethanesulfonic acid (5.7 g, 38 mmol) was slowly added dropwise to the reaction mixture, and the mixture was stirred at room temperature for 2 hours. The reaction was terminated by dropwise addition of D ₂ O to the reaction mixture, and potassium phosphate (30 wt% in H ₂ O, 6.3 g, 45 mmol) was added dropwise to adjust the pH of the aqueous layer to 9-10. The organic layer was separated by washing with dichloromethane/water. The water was removed with magnesium sulfate and passed through a Celite/Florisil/Silica pad. The passed solution was concentrated under reduced pressure, followed by column purification with hexane/ethyl acetate to prepare 9.7 g of compound BH1 (o+p+q+r = 21-23).

MS:[M+H] ⁺ = 529

Synthesis Example 2: Preparation of compound BH2

(Synthesis Example 2-1)

9-Bromo-10-(1-naphthyl)anthracene (8 g, 21 mmol), dibenzofuranyl-2-boronic acid (4.6 g, 21.5 mmol), potassium carbonate (6 g, 44 mmol), Pd (Amphos) ₂ Cl ₂ (15 mg, 0.02 mmol) and Aliquat 336 (0.2 g, 0.53 mmol) were placed in a 250 mL round-bottom flask, dissolved in 100 mL of toluene and 30 mL of water, and then the temperature of the reactor was raised to 80 °C. Stir overnight. After completion of the reaction, the reaction product was cooled to room temperature, diluted sufficiently in ethyl acetate, and washed with EtOAc/brine to separate the organic layer. Water was removed with magnesium sulfate and passed through a Celite-Florisil-Silica pad. The passed solution was concentrated under reduced pressure, and purified by hexane/ethyl acetate column chromatography to obtain an intermediate X2 (8.7 g, yield 88%).

(Synthesis Example 2-2)

Intermediate X2 (8.7 g, 18 mmol) was placed in a 250 mL round bottom flask under a nitrogen atmosphere and dissolved in benzene-D6 (454 g, 5.4 mol). Then, trifluoromethanesulfonic acid (13.5 g, 90 mmol) was slowly added dropwise to the reaction mixture, and the mixture was stirred at room temperature for 2 hours. D ₂ O was added dropwise to the reaction mixture to terminate the reaction, and potassium phosphate (30 wt% in H ₂ O, 6.3 g, 45 mmol) was added dropwise to adjust the pH of the aqueous layer to 9-10. The organic layer was separated by washing with dichloromethane/water. Water was removed with magnesium sulfate and passed through a Celite-Florisil-Silica pad. After concentrating the passed solution, compound BH2 (8.1 g, yield 91%, deuterated product s+p+r = 21-22) was prepared by hexane/ethyl acetate column chromatography separation method.

MS: [M+H] ⁺ = 492

Synthesis Example 3: Preparation of compound BD1

(Synthesis Example 3-1)

250 of compound a1 (5.0 g, 13.7 mmol), 1-Bromonaphthalen-2-ol (6.1 g, 27.4 mmol), sodium carbonate (5.8 g, 54.8 mmol), Pd(PPh ₃ ) ₄ (0.16 g, 0.14 mmol) Into an mL round-bottom flask, 70 mL of anhydrous toluene (0.2 M) and 20 mL of distilled water were added. The mixture was stirred overnight at a bath temperature of 100°C. After cooling to room temperature, the reactant was passed through a Celite/Floricil/Silica pad while flowing with toluene. The filtrate was concentrated under reduced pressure and precipitated with methanol/tetrahydrofuran to obtain an intermediate a2.

(Synthesis Example 3-2)

Intermediate a2 (3.5 g, 8.8 mmol) and potassium carbonate (6.1 g, 43.9 mmol) were placed in a 250 mL round bottom flask and dissolved in 90 mL of NMP (0.1 M), followed by stirring at a bath temperature of 180° C. overnight. After cooling to room temperature, hexane and water were added dropwise to precipitate, filtered, and washed with tetrahydrofuran and methanol to obtain an intermediate a3.

(Synthesis Example 3-3)

Intermediate a3 (3.0 g, 8.4 mmol) and bromine (Br ₂ ) (4.7 g, 29.3 mmol) were placed in a 500 mL round bottom flask, and 280 mL of chloroform (0.03 M) was added thereto. The mixture was stirred for two days under a bath temperature of 40°C. Tetrahydrofuran and methanol were added dropwise to the reaction mixture to precipitate, followed by filtration to obtain an intermediate a.

(Synthesis Example 3-4)

Intermediate a (2.0 g, 3.9 mmol), diphenylamine (1.4 g, 8.5 mmol), sodium t-butoxide (0.82 g, 8.5 mmol), Pd(P( t -Bu) ₃ ) ₂ (0.20 g, 0.39 mmol) Put into a 500 mL round-bottom flask, fill with nitrogen, and then add 160 mL of toluene (0.025 M). Then, the mixture is stirred for 6 hours at a bath temperature of 110°C. After cooling to room temperature, the mixture was washed with water, hexane, and methanol, and recrystallized from chlorobenzene to obtain compound BD1.

MS: [M+H] ⁺ = 693

Synthesis Example 4: Preparation of compound BD2

Compound BD2 was prepared in the same manner as in Synthesis Example 3, except that intermediate b was used instead of diphenylamine of Synthesis Example 3-4.

MS: [M+H] ⁺ = 1025

Synthesis Example 5: Preparation of compound BD3

Intermediate a (2.0 g, 3.9 mmol), Intermediate c (2.5 g, 8.6 mmol), potassium carbonate (1.6 g, 11.7 mmol), Pd(PPh ₃ ) ₄ (0.45 g, 0.39 mmol) were added to a 500 mL round bottom flask. 160 mL of anhydrous toluene (0.025 M) and 40 mL of distilled water were added thereto. The mixture was stirred overnight at a bath temperature of 100°C. After cooling to room temperature, the mixture was washed with water, hexane, and methanol, and recrystallized from chlorobenzene to obtain compound BD3.

MS: [M+H] ⁺ = 845

Synthesis Example 6: Preparation of compound BD4

(Synthesis Example 6-1)

Intermediate d1 (10.0 g, 20.4 mmol) and triphenylphosphine (26.8 g, 102.0 mmol) were placed in a 500 mL round bottom flask and dissolved in 270 mL of anhydrous 1,2-dichlorobenzene (0.075 M). The mixture was stirred overnight at a bath temperature of 180°C. After cooling the reaction product with stirring at room temperature for 2 hours, n-hexane is added dropwise and precipitated while stirring for 2 hours. The precipitate was washed with n-hexane and chloroform and filtered to obtain an intermediate d2.

(Synthesis Example 6-2)

Intermediate d2 (5.0 g, 11.8 mmol), NaO t -Bu (6.8 g, 70.8 mmol) is placed in a 1 L round bottom flask and dissolved in 400 mL of anhydrous toluene (0.03 M). Iodobenzene (16.9 g, 82.6 mmol) was added dropwise to the reaction. Pd(P( t -Bu) ₃ ) ₂ (1.2 g, 2.36 mmol) was added dropwise to the reaction product at a bath temperature of 110° C., and the mixture was stirred for 24 hours. After cooling the reaction product with stirring at room temperature for 2 hours, methanol was added dropwise and stirred for 30 minutes to precipitate. The precipitate was washed with toluene, methanol, and hexane and filtered to obtain an intermediate d.

(Synthesis Example 6-3)

Compound BD4 was prepared in the same manner as in Synthesis Example 3-4, except that Intermediate d was used instead of Intermediate a in Synthesis Example 3-4.

MS: [M+H] ⁺ = 843

[Example]

Example 1: Fabrication of an organic light emitting device

A glass substrate on which indium tin oxide (ITO) was deposited to a thickness of 500 Å was placed in distilled water in which detergent was dissolved and washed with ultrasonic waves. In this case, a product manufactured by Fisher Co. was used as the detergent, and distilled water filtered secondarily through a filter manufactured by Millipore Co. was used as the distilled water. After washing 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 with acetone, distilled water, and isopropyl alcohol, and drying was performed to prepare a washed ITO glass substrate.

A composition obtained by mixing the following compounds Z-1 and Z-2 in a weight ratio of 8:2 on the ITO transparent electrode was spin-coated and cured at 220°C and 30 minutes on a hot plate under a nitrogen atmosphere to form a hole injection layer with a thickness of 400 Å. formed. On the hole injection layer, a composition obtained by dissolving the following compound Z-3 in toluene at a weight ratio of 1% was spin-coated and heat-treated on a hot plate at 200° C. and 30 minutes to form a hole transport layer having a thickness of 200 Å. On the hole transport layer, a composition obtained by dissolving compound BH1 and compound BD1 prepared above in a weight ratio of 98:2 in toluene at a weight ratio of 0.5% was spin-coated to form a light emitting layer having a thickness of 250 Å, and under a nitrogen atmosphere at 120° C. on a hot plate, The coating composition was dried under conditions of 10 minutes. Then, the following compound Z-4 (electron transport layer, 300 Å), LiF (electron injection layer, 10 Å), and Al (cathode, 1000 Å) were sequentially deposited by transferring to a vacuum evaporator to manufacture an organic light emitting device. In the above process, a deposition rate of 0.3 Å/sec for LiF and 2 Å/sec for aluminum (Al) was maintained, and the vacuum degree during deposition was maintained at 2x10 ^-7 to 5x10 ^-8 torr.

Examples 2 to 8

An organic light emitting diode was manufactured in the same manner as in Example 1, except that the compounds shown in Table 1 were used instead of the compounds BH1 and BD1.

Comparative Examples 1 to 10

An organic light emitting diode was manufactured in the same manner as in Example 1, except that the compounds shown in Table 1 were used instead of the compounds BH1 and BD1. Compounds A to B of Table 1 are as follows, and compounds X1 and X2 are compounds prepared in Synthesis Example 1-1 and Synthesis Example 2-1, respectively.

Experimental Example: Characteristics Evaluation of Organic Light-Emitting Devices

The driving voltage, quantum efficiency, and lifetime (T95) values of the organic light emitting diodes manufactured in Examples 1 to 8 and Comparative Examples 1 to 10 were measured at a current density of 10 mA/cm ² , and the results are shown below. The quantum efficiency was calculated as "(the number of emitted photons)/(the number of injected charge carriers) x 100", and the lifetime (T95) means the time it takes for the luminance to decrease from the initial luminance to 95%.

light emitting layer
host light emitting layer
dopant drive voltage
(V) quantum efficiency
(%) T95
(hr) Example 1 compound BH1 compound BD1 4.61 8.25 145 Example 2 compound BH1 compound BD2 4.60 8.17 129 Example 3 compound BH1 compound BD3 4.60 8.20 115 Example 4 compound BH1 compound BD4 4.62 8.09 130 Example 5 compound BH2 compound BD1 4.56 7.99 161 Example 6 compound BH2 compound BD2 4.58 8.13 134 Example 7 compound BH2 compound BD3 4.53 8.32 139 Example 8 compound BH2 compound BD4 4.58 8.22 152 Comparative Example 1 compound BH1 compound A 4.67 7.13 92 Comparative Example 2 compound BH1 compound B 4.70 7.20 85 Comparative Example 3 compound BH2 compound A 4.62 6.83 99 Comparative Example 4 compound BH2 compound B 4.60 6.72 78 Comparative Example 5 compound X1 compound BD1 4.74 7.70 74 Comparative Example 6 compound X1 compound BD2 4.72 7.39 79 Comparative Example 7 compound X1 compound A 4.75 5.23 52 Comparative Example 8 compound X2 compound BD1 4.68 6.99 85 Comparative Example 9 compound X2 compound BD3 4.71 6.70 80 Comparative Example 10 compound X2 compound B 4.67 4.91 61

As shown in Table 1, it can be seen that the organic light emitting device using the compound of the present invention in combination as a host and a dopant in the light emitting layer exhibits very excellent properties in terms of quantum efficiency and lifespan compared to the organic light emitting device of Comparative Example.

1: Substrate 2: Anode
3: light emitting layer 4: cathode
5: hole injection layer 6: hole transport layer
7: electron transport layer 8: electron injection layer

Claims (13)

anode; cathode; and 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 device:
[Formula 1]

In Formula 1,
Y ₁ and Y ₂ are each independently O, S, Se, Te, or NR';
R' is each independently hydrogen; substituted or unsubstituted C _1-60 alkyl; substituted or unsubstituted C _6-60 aryl; Or substituted or unsubstituted C _2-60 heteroaryl containing any one or more heteroatoms selected from the group consisting of N, O and S,
L ₁ and L ₂ are each independently, a single bond; substituted or unsubstituted C _6-60 arylene; Or substituted or unsubstituted C _2-60 heteroarylene containing any one or more heteroatoms selected from the group consisting of N, O and S,
Ar ₁ to Ar ₄ are each independently, substituted or unsubstituted C _6-60 aryl; Or substituted or unsubstituted C _2-60 heteroaryl containing any one or more heteroatoms selected from the group consisting of N, O and S,
[Formula 2]

In Formula 2,
Ar ₁₁ is C _6-60 aryl substituted with one or more deuterium; Or C _2-60 heteroaryl comprising any one or more heteroatoms selected from the group consisting of N, O and S substituted with one or more deuterium;
Ar ₁₂ is C _6-60 aryl substituted with one or more deuterium; Or C _2-60 heteroaryl comprising any one or more heteroatoms selected from the group consisting of N, O and S substituted with one or more deuterium;
R ₁₁ is deuterium,
z is an integer from 0 to 8;
According to claim 1,
Y ₁ and Y ₂ are each independently O, S, or NR';
each R' is independently methyl; phenyl; phenyl substituted with 5 deuterium; or t-butylphenyl;
organic light emitting device.
3. The method of claim 2,
Y ₁ and Y ₂ are both O;
organic light emitting device.
According to claim 1,
L ₁ and L ₂ are each independently, a single bond; unsubstituted phenylene; phenylene substituted with 1 or 2 C _1-10 alkyl; phenylene substituted with 1 to 2 halogens; phenylene substituted with 4 deuterium; pyrimidinediyl; tetrazindiyl; or thiophenediyl;
organic light emitting device.
5. The method of claim 4,
L ₁ and L ₂ are each independently, a single bond; phenylene; dimethylphenylene; fluorophenylene; difluorophenylene; phenylene substituted with 4 deuterium; pyrimidinediyl; tetrazindiyl; or thiophenediyl;
organic light emitting device.
According to claim 1,
Ar ₁ to Ar ₄ are each independently, substituted or unsubstituted C _6-20 aryl; or C _2-20 heteroaryl comprising any one or more heteroatoms selected from the group consisting of substituted or unsubstituted N, O and S;
organic light emitting device.
7. The method of claim 6,
Ar ₁ to Ar ₄ are each independently any one selected from the group consisting of
Organic light emitting device:

above,
n and m are each independently an integer of 0 to 2,
R'' is each independently C _1-10 alkyl,
Ar'' is each independently C _2-10 heteroaryl including any one or more heteroatoms selected from the group consisting of N, O and S;
each X is independently C(R _a- )(R _b ), O or S;
R _a and R _b are each independently hydrogen or C _1-10 alkyl.
7. The method of claim 6,
Ar ₁ to Ar ₄ are each independently any one selected from the group consisting of
Organic light emitting device:

7. The method of claim 6,
Ar ₁ and Ar ₃ are the same as each other,
Ar ₂ and Ar ₄ are the same as each other,
organic light emitting device.
According to claim 1,
The compound represented by Formula 1 is any one selected from the group consisting of
Organic light emitting device:

According to claim 1,
Ar ₁₁ is naphthyl substituted with one or more deuterium, or naphthylphenyl substituted with one or more deuterium;
organic light emitting device.
According to claim 1,
Ar ₁₂ is naphthylphenyl substituted with one or more deuterium, or dibenzofuranyl substituted with one or more deuterium;
organic light emitting device.
According to claim 1,
Formula 2 is represented by any one of the following Formulas 2-1 to 2-4,
Organic light emitting device:
[Formula 2-1]

In Formula 2-1,
o+p+q+r is an integer from 21 to 23;
[Formula 2-2]

In Formula 2-2,
o+p+q+r is an integer from 21 to 23;
[Formula 2-3]

In Formula 2-3,
s+p+r is an integer from 21 to 22,
[Formula 2-4]

In Formula 2-4,
s+p+q+r is an integer from 23 to 24.

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