KR102374169B1 - Compound for forming capping layer and organic electroluminescent divice including the same - Google Patents

Abstract

The present application relates to a compound for forming a capping layer, and an organic light emitting device comprising the same, and the compound for forming a capping layer according to an embodiment of the present invention is applied to an organic light emitting device to provide external luminous efficiency, color coordinates and lifespan of the organic light emitting device can improve

Description

Compound for forming a capping layer and an organic light emitting device comprising the same

The present application relates to a compound for forming a capping layer and an organic light emitting device including the same.

In general, an organic light emitting device refers to a device that converts electrical energy into light energy using an organic material. In general, the organic light emitting device may have a structure in which an anode is formed on a substrate, and a hole transport layer, a light emitting layer, an electron transport layer, and a cathode are sequentially formed on the anode.

In the organic light emitting device, when a voltage is applied between the anode and the cathode, holes are injected from the anode, the injected holes are moved to the light emitting layer via the hole transport layer, and electrons are simultaneously injected from the cathode, and the injected electrons pass through the electron transport layer. through the light emitting layer. Holes and electrons moved to the light emitting layer recombine to generate excitons. As the exciton changes from an excited state to a ground state, light is generated.

The efficiency of the organic light emitting diode can be generally divided into internal light emitting efficiency and external light emitting efficiency. The internal luminous efficiency is related to how efficiently excitons are generated in the organic material layer formed between the first electrode and the second electrode, such as a hole transport layer, a light emitting layer, and an electron transport layer, to achieve light conversion. Theoretically, the internal luminous efficiency is known to be about 25% for fluorescence and about 100% for phosphorescence.

On the other hand, the external luminous efficiency refers to the efficiency at which light generated in the organic material layer formed between the first and second electrodes is extracted to the outside of the organic light emitting device, and is generally known to be extracted to the outside at a level of about 20% of the internal luminous efficiency. there is.

In order to prevent total reflection and loss of light exiting to the outside as a method to increase the external luminous efficiency, that is, light extraction, various organic compounds have been applied as a capping layer, and in order to improve the performance of the organic light emitting device, Efforts have been made to develop organic compounds having high refractive index and thin film stability that can improve external luminous efficiency.

Korean Patent Publication 10-2004-0098238

The present application provides a compound for forming a capping layer capable of improving color purity and external luminous efficiency of an organic light emitting device by having a wide band gap that does not affect the RGB wavelength of the organic light emitting device and at the same time having a high refractive index, and the capping layer formation An organic light emitting device including a capping layer containing a solvent compound is provided.

However, the problems to be solved by the present application are not limited to the problems described above, and other problems not described will be clearly understood by those skilled in the art from the following description.

A first aspect of the present application provides a compound for forming a capping layer, which is represented by the following Chemical Formula 1 and is disposed on the outside of an electrode of an organic light emitting device:

[Formula 1]

In Formula 1,

Ar is a substituted or unsubstituted C _6-50 arylene group, or a substituted or unsubstituted C _5-50 heteroarylene group,

Ar ₁ And Ar ₂ are each independently a substituted or unsubstituted C _6-50 aryl group, or a substituted or unsubstituted C _5-50 heteroaryl group,

Ar, Ar ₁ and Ar ₂ At least one of them is a substituted or unsubstituted diarylfluorene, and N and carbazole of NAr ₁ Ar ₂ bonded to Ar have a structure in which they are in a para position with each other,

R ₁ to R ₃ are each independently hydrogen, deuterium, a substituted or unsubstituted C _1-30 alkyl group, a substituted or unsubstituted C _1-30 alkoxy group, or a substituted or unsubstituted C _2-30 alkenyl group , a substituted or unsubstituted C _6-50 aryl group, or a substituted or unsubstituted C _5-50 heteroaryl group,

l is an integer from 0 to 4, and m is an integer from 0 to 3.

A second aspect of the present disclosure includes first and second electrodes; an organic material layer interposed inside the first and second electrodes; and a capping layer disposed outside at least one of the first and second electrodes, the capping layer containing the compound for forming a capping layer according to the present invention;

The compound for forming a capping layer according to an embodiment of the present invention has a wide band gap that does not affect the RGB wavelength of the organic light emitting device and has a high refractive index, thereby improving the color purity and external luminous efficiency of the organic light emitting device. there is.

In addition, the compound for forming a capping layer according to an embodiment of the present invention can form a stable thin film as the packing density is increased due to excellent molecular arrangement. In addition, high Tg and Td suppress intermolecular recrystallization to prevent heat generated during driving of the organic light emitting diode, and it is possible to reduce contamination inside the organic light emitting element from external air and moisture, thereby improving the lifespan of the organic light emitting element. can do it

1 is a schematic diagram of an organic light emitting device according to an exemplary embodiment of the present application.

Hereinafter, with reference to the accompanying drawings, embodiments and examples of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily carry out.

However, the present application may be embodied in several different forms and is not limited to the embodiments and examples described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout this specification, when a member is said to be located “on” another member, this includes not only a case in which a member is in contact with another member but also a case in which another member is present between the two members.

Throughout this specification, when a part "includes" a component, it means that other components may be further included, rather than excluding other components, unless otherwise stated. As used throughout this specification, the terms "about," "substantially," and the like are used in a sense at or close to the numerical value when the manufacturing and material tolerances inherent in the stated meaning are presented, and are intended to enhance the understanding of this application. To help, precise or absolute figures are used to prevent unfair use by unconscionable infringers of the stated disclosure. The term “step of” or “step of” to the extent used throughout this specification does not mean “step for”.

Throughout this specification, the term "combination of these" included in the expression of the Markush form means one or more mixtures or combinations selected from the group consisting of the components described in the expression of the Markush form, and the components It is meant to include one or more selected from the group consisting of.

Throughout this specification, reference to “A and/or B” means “A or B, or A and B”.

Throughout this specification, the term "aryl" refers to a C _5-50 aromatic hydrocarbon ring group, for example, phenyl, benzyl, naphthyl, biphenyl, terphenyl, fluorene, phenanthrenyl, triphenylenyl, peryle. is meant to include aromatic rings such as nyl, chrysenyl, fluoranthenyl, benzofluorenyl, benzotriphenylenyl, benzochrysenyl, anthracenyl, stilbenyl, pyrenyl, etc., "heteroaryl" means at least one As a C _3-50 aromatic ring containing a hetero element, for example, pyrrolyl, pyrazinyl, pyridinyl, indolyl, isoindolyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, Benzothiophenyl, dibenzothiophenyl, quinolyl group, isoquinolyl, quinoxalinyl, carbazolyl, phenanthridinyl, acridinyl, phenanthrolinyl, thienyl, and pyridine ring, pyrazine ring, pyrimidine ring , pyridazine ring, triazine ring, indole ring, quinoline ring, acridine ring, pyrrolidine ring, dioxane ring, piperidine ring, morpholine ring, piperazine ring, carbazole ring, furan ring, thi Offene ring, oxazole ring, oxadiazole ring, benzoxazole ring, thiazole ring, thiadiazole ring, benzothiazole ring, triazole ring, imidazole ring, benzoimidazole ring, pyran ring, dibenzofuran It may mean including a heterocyclic group formed from a ring.

Throughout this specification, the term "which may be substituted" refers to deuterium, halogen, amino group, nitrile group, nitro group, or C ₁ to C ₃₀ alkyl group, C ₂ to C ₃₀ alkenyl group, C ₁ to C ₃₀ alkoxy group, C ₃ ~ C ₂₀ Cycloalkyl group, C ₃ ~ C ₂₀ Heterocycloalkyl group, C ₆ ~ C ₃₀ Aryl group and C ₃ ~ C ₃₀ It means that may be substituted with one or more groups selected from the group consisting of a heteroaryl group can do. In addition, the same symbols throughout the present specification may have the same meaning unless otherwise specified.

A first aspect of the present application provides a compound for forming a capping layer, which is represented by the following Chemical Formula 1 and is disposed on the outside of an electrode of an organic light emitting device:

[Formula 1]

In Formula 1,

Ar is a substituted or unsubstituted C _6-50 arylene group, or a substituted or unsubstituted C _5-50 heteroarylene group,

Ar ₁ And Ar ₂ are each independently a substituted or unsubstituted C _6-50 aryl group, or a substituted or unsubstituted C _5-50 heteroaryl group,

Ar, Ar ₁ and Ar ₂ At least one of them is a substituted or unsubstituted diarylfluorene, and N and carbazole of NAr ₁ Ar ₂ bonded to Ar have a structure in which they are in a para position with each other,

R ₁ to R ₃ are each independently hydrogen, deuterium, a substituted or unsubstituted C _1-30 alkyl group, a substituted or unsubstituted C _1-30 alkoxy group, or a substituted or unsubstituted C _2-30 alkenyl group , a substituted or unsubstituted C _6-50 aryl group, or a substituted or unsubstituted C _5-50 heteroaryl group,

l is an integer from 0 to 4, and m is an integer from 0 to 3.

The compound for forming a capping layer of Formula 1 according to an embodiment of the present invention has a structure in which an arylamine is bonded to the para-position through an arylene linking group at the 3-position of the carbazole. N of the arylene linking group (Ar) and the arylamine (NAr ₁ Ar ₂ ) and the 3rd position of the arylene linking group (Ar) and carbazole are connected to each other at a para position. That is, the arylene linking group (Ar) and the N of the arylamine (NAr ₁ Ar ₂ ) and the 3rd position of the arylene linking group (Ar) and the carbazole may be linearly positioned with each other. For example, the arylene linking group connected to the para (para) position may be a phenylene group connected to the 1st and 4th positions or a fluorene group connected to the 2nd or 7th position.

The compound according to the present invention can maintain a wide band gap by bonding the arylamine to the para-position through the arylene linkage at the 3-position of the carbazole. In addition, the arylene linking group or arylamine contains diarylfluorene, and thus has a high refractive index, and excellent molecular arrangement and intermolecular packing during thin film production can form a stable thin film. In addition, due to diarylfluorene, it has high Tg and Td even at a relatively low molecular weight, so recrystallization of the thin film can be suppressed, and the organic light emitting device can be protected from external air and moisture due to excellent thermal stability.

That is, when the capping layer containing the compound according to an embodiment of the present invention is disposed on the outside of the electrode of the organic light-emitting device, external light-emitting efficiency can be improved. When light generated from the organic material layer interposed inside the first and second electrodes of the organic light emitting device is extracted to the outside of the organic light emitting device, it is possible to prevent loss of light emitted to the outside due to total reflection.

The compound for forming a capping layer according to an embodiment of the present invention may have a high refractive index due to its structural characteristics, and has excellent thin film stability. Lifespan can be improved.

According to one embodiment of the present invention, Ar in Formula 1 may be substituted or unsubstituted phenylene, naphthylene, biphenylene, terphenylene, fluorene, or a combination thereof.

In addition, according to one embodiment of the present invention, Ar ₁ and Ar ₂ in Formula 1 may each independently be phenyl, naphthyl, biphenyl, terphenyl, fluorenyl, or a combination thereof.

In addition, according to one embodiment of the present invention, in Formula 1, R ₁ may be phenyl, biphenyl, naphthyl or phenylnaphthyl, specifically phenyl.

In one embodiment of the present invention, the compound for forming the capping layer may be represented by the following Chemical Formula 2 or Chemical Formula 3.

[Formula 2] [Formula 3]

In Formula 2 or Formula 3,

Ar ₃ and Ar ₄ are each independently a substituted or unsubstituted C _{6 to 37} aryl group, or a substituted or unsubstituted C _{5 to 37} heteroaryl group,

R ₄ and R ₅ are each independently hydrogen, deuterium, a substituted or unsubstituted C _{1 to 37} alkyl group, a substituted or unsubstituted C _{1 to 37} alkoxy group, or a substituted or unsubstituted C _{2 to 37} alkenyl group , a substituted or unsubstituted C _{6 to 37} aryl group, or a substituted or unsubstituted C _{5 to 37} heteroaryl group,

L, L ₁ and L ₂ are each independently a direct bond, a substituted or unsubstituted C _{6 ~ 37} arylene group, or a substituted or unsubstituted C _{5 ~ 37} heteroarylene group,

n, n', and o' are each independently an integer from 0 to 3, and o is an integer from 0 to 4.

In the compound represented by Formula 2, arylamine has a diarylfluorene substituent, and in the compound represented by Formula 3, carbazole and arylamine are connected through diarylfluorene. In Formula 3, the nitrogen of the carbazole and arylamine (NAr ₁ Ar ₂ ) may be connected to the para position through diarylfluorene, which is an arylene linking group (Ar). That is, based on the two benzene rings of fluorene, the nitrogen of carbazole and arylamine may have a para-linking position. In Formula 3, the para-connected position means that the 2nd and 7th positions of diarylfluorene can be used as bonding positions. Although a straight line of 180 degrees is not formed on the structure of diarylfluorene, the N of diarylfluorene and arylamine (NAr ₁ Ar ₂ ) as the arylene linking group (Ar) may be positioned on a linear phase.

Since the compound represented by Formula 2 or Formula 3 contains diarylfluorene to increase refractive index and external quantum efficiency, it is very suitable for use as a capping layer. In addition, the color purity of the organic light emitting device may not be deteriorated by maintaining a wide band gap that cannot absorb the wavelength of the RGB region of the organic light emitting device.

In addition, the compound represented by Formula 2 or Formula 3 may form a stable thin film due to excellent molecular arrangement and intermolecular packing, and may improve lifespan by protecting the organic light emitting device from external air and moisture.

In addition, the compound represented by Formula 2 or Formula 3 may suppress intermolecular recrystallization due to high Tg and Td, and may be stable from heat generated during operation.

Also, in one embodiment of the present invention, the compound for forming the capping layer may be represented by the following Chemical Formula 4 or Chemical Formula 5.

[Formula 4] [Formula 5]

In Formula 4 or Formula 5,

R ₆ and R ₇ are each independently hydrogen, deuterium, a substituted or unsubstituted C _1-25 alkyl group, a substituted or unsubstituted C _1-25 alkoxy group, or a substituted or unsubstituted C _2-25 alkenyl group , a substituted or unsubstituted C _6-25 aryl group, or a substituted or unsubstituted C _5-25 heteroaryl group,

p and q are each independently an integer from 0 to 5;

In the compound represented by Formula 4, the arylamine has diphenylfluorene as an aryl group. According to one embodiment of the present invention, the nitrogen of the arylamine may be connected to the 2-position of diphenylfluorene.

In addition, in the compound represented by Formula 5, carbazole and arylamine are connected through positions 2 and 7 of diphenylfluorene. The compound having such a structure can maintain a linear molecular structure, so that it is possible to maximize the external light emitting efficiency and lifespan of the organic light emitting device due to excellent molecular arrangement in a thin film and excellent stability.

In addition, according to one embodiment of the present invention, in Formulas 2 to 5, Ar, L ₁ and L ₂ are substituted or unsubstituted phenylene, naphthylene, biphenylene, terphenylene, fluorene, or these may be a combination of

Also, according to one embodiment of the present invention, in Formulas 2 to 5, Ar ₁ and Ar ₂ may each independently be phenyl, naphthyl, biphenyl, terphenyl, fluorenyl, or a combination thereof.

Also, in one embodiment of the present invention, the compound for forming the capping layer may be represented by the following Chemical Formula 6 or Chemical Formula 7.

[Formula 6] [Formula 7]

In Formula 6 or Formula 7,

r is an integer from 1 to 4, and s, t, and u are each independently an integer from 0 to 3.

The compound represented by Formula 6 has one or more phenylene as a linking group, the nitrogen of arylamine has diphenylfluorene as an aryl group, and the diphenylfluorene is directly connected to nitrogen or one or more phenylenes can be connected through According to one embodiment of the present invention, diphenyl fluorene may be connected to nitrogen at No. 2 position.

In addition, the compound represented by Formula 7 may have diphenylfluorene as an arylene linking group, and the diphenylfluorene may be connected to N of carbazole and arylamine through a direct bond or one or more phenylenes. In addition, in the compound of Formula 7, carbazole and arylamine are connected through positions 2 and 7 of diphenylfluorene. The compound having such a structure can maintain a linear molecular structure, so that it is possible to maximize the external light emitting efficiency and lifespan of the organic light emitting device due to excellent molecular arrangement in a thin film and excellent stability.

In addition, according to one embodiment of the present invention, in Formulas 2 to 7, R ₁ may be phenyl, biphenyl, naphthyl, or phenylnaphthyl, specifically phenyl.

In one embodiment of the present invention, the compounds for forming a capping layer represented by Chemical Formulas 1 to 7 may be synthesized by the following reaction scheme, but are not limited thereto, and may be synthesized by various methods.

[reaction formula]

In one embodiment of the present invention, the compound represented by Formula 1 may be any one of the compounds 1 to 390 presented below, and may not be limited thereto:

A second aspect of the present application provides an organic light emitting device in which a capping layer including a compound represented by any one of Formulas 1 to 7 is disposed.

According to one embodiment of the present invention, an organic light emitting device includes first and second electrodes; an organic material layer interposed inside the first and second electrodes; and a capping layer disposed on the outside of at least one of the first and second electrodes and containing the compound for forming a capping layer according to any one of claims 1 to 7. Here, a side adjacent to the organic material layer interposed between the first electrode and the second electrode among both sides of the first electrode or the second electrode is referred to as an inner side, and a side not adjacent to the organic material layer is referred to as an outer side. That is, when the capping layer is disposed outside the first electrode, the first electrode is interposed between the capping layer and the organic material layer, and when the capping layer is disposed outside the second electrode, the second electrode is interposed between the capping layer and the organic material layer do.

According to one embodiment of the present invention, in the organic light emitting device, various organic material layers may be interposed inside the first electrode and the second electrode, and a capping layer may be formed outside at least one of the first and second electrodes. . The capping layer may be formed on both the outer side of the first electrode and the outer side of the second electrode, or may be disposed on the outer side of the first electrode or the outer side of the second electrode. The capping layer may include the compound for forming the capping layer according to the present invention. In addition, according to one embodiment of the present invention, organic material layers having various additional functions may be formed on the outside of the first and second electrodes with the capping layer interposed therebetween. That is, a capping layer is directly formed on the outer surface of the first electrode (or second electrode), or an organic material layer having various functions is formed on the outer surface of the first electrode (or second electrode), and the organic material layer of the present invention is formed on the organic material layer. A capping layer containing the compound may be formed.

According to one embodiment of the present invention, the capping layer may include the compound for forming the capping layer according to the embodiment of the present invention alone, or may include two or more or known compounds together.

The organic light emitting device according to an embodiment of the present invention includes one or more organic material layers between first and second electrodes, that is, inside the first and second electrodes, and a capping layer on the outside of the first and second electrodes. can be formed. The organic material layer may generally be a hole transport layer, a light emitting layer, and an electron transport layer constituting the light emitting part, but may not be limited thereto.

The organic light emitting device includes a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), an electron transport layer (ETL), and electron injection between a first electrode (anode) and a second electrode (cathode, cathod). One or more organic material layers constituting the light emitting part such as the layer (EIL) may be included.

For example, the organic light emitting device may be manufactured as shown in FIG. 1 . The organic light emitting device from below is a first electrode (anode, hole injection electrode 1000) / capping layer 3000 / hole injection layer 200 / hole transport layer 300 / light emitting layer 400 / electron transport layer 500 / The electron injection layer 600/second electrode (cathode, electron injection electrode 2000/capping layer 3000) may be stacked in this order.

As described above, the compound for forming a capping layer according to an embodiment of the present invention has a structure in which an arylene linking group is bonded to the 3rd position of the carbazole, and the nitrogen of an arylamine is connected to the para position of the arylene linking group. By having it, it has a high refractive index, and excellent intermolecular packing during thin film production can form a stable capping layer. Accordingly, external luminous efficiency, color coordinates, and lifespan of the organic light emitting diode can be improved.

In FIG. 1 , the substrate 100 may be a substrate used in an organic light emitting device, and in particular, a transparent glass substrate or a flexible plastic substrate excellent in mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance. there is.

The hole injection electrode 1000 is used as an anode for hole injection of the organic light emitting diode. A material having a low work function is used to allow hole injection, and may be formed of a transparent material such as indium tin oxide (ITO), indium zinc oxide (IZO), or graphene.

The hole injection layer 200 may be formed by depositing a hole injection layer material on the anode electrode by a method such as a vacuum deposition method, a spin coating method, a casting method, or a Langmuir-Blodgett (LB) method. In the case of forming the hole injection layer by the vacuum deposition method, the deposition conditions vary depending on the compound used as the material of the hole injection layer 200, the structure and thermal characteristics of the desired hole injection layer, etc., but generally at 50-500 ° C. A deposition temperature, a vacuum degree of 10 ^{- 8} to 10 ^{- 3} torr, a deposition rate of 0.01 to 100 Å/sec, and a layer thickness of 10 Å to 5 μm may be appropriately selected. In addition, a charge generating layer may be additionally deposited on the surface of the hole injection layer if necessary. A conventional material may be used as the material for the charge generation layer, for example, HATCN.

Next, the hole transport layer 300 may be formed by depositing a hole transport layer material on the hole injection layer 200 by a method such as a vacuum deposition method, a spin coating method, a casting method, a LB method, or the like. In the case of forming the hole transport layer by the vacuum deposition method, the deposition conditions vary depending on the compound used, but in general, it is preferable to select the hole transport layer within the same range of conditions as that of the hole injection layer.

The hole transport layer 300 may be formed using a known compound. According to one embodiment of the present invention, the hole transport layer 300 may have one or more layers, and a light emitting auxiliary layer may be formed on the hole transport layer 300 .

The light emitting layer 400 may be formed by depositing a light emitting layer material on the hole transport layer 300 or the light emitting auxiliary layer by a method such as a vacuum deposition method, a spin coating method, a casting method, a LB method, or the like. In the case of forming the light emitting layer by the vacuum deposition method, the deposition conditions vary depending on the compound used, but in general, it is preferable to select the light emitting layer within the same range of conditions as those for the formation of the hole injection layer. In addition, as the light emitting layer material, a known compound may be used as a host or a dopant.

In addition, when used with a phosphorescent dopant in the light emitting layer, a hole blocking material (HBL) may be additionally laminated by a vacuum deposition method or a spin coating method in order to prevent the phenomenon of triplet excitons or holes from being diffused into the electron transport layer. At this time, the hole-blocking material that can be used is not particularly limited, but any one of the known hole-blocking materials used as the hole-blocking material can be selected and used. For example, an oxadiazole derivative, a triazole derivative, a phenanthroline derivative, or a hole-inhibiting material described in Japanese Patent Application Laid-Open No. Hei 11-329734 (A1), etc. are mentioned. Representatively, Balq (bis(8-hydra) Roxy-2-methylquinolinol nato)-aluminum biphenoxide), phenanthrolines-based compounds (eg, UDC's BCP (vasocuproin)), etc. may be used.

The electron transport layer 500 is formed on the light emitting layer 400 formed as described above. In this case, the electron transport layer may be formed by a vacuum deposition method, a spin coating method, a casting method, or the like. In addition, although the deposition conditions of the electron transport layer vary depending on the compound used, in general, it is preferable to select the electron transport layer in substantially the same condition range as the formation of the hole injection layer.

Thereafter, the electron injection layer 600 may be formed by depositing an electron injection layer material on the electron transport layer 500 , wherein the electron transport layer is a conventional electron injection layer material by vacuum deposition, spin coating, or casting. It can be formed by a method such as a method.

The hole injection layer 200 , the hole transport layer 300 , the light emitting layer 400 , and the electron transport layer 500 of the organic light emitting device may use the following materials, but is not limited thereto.

A cathode 2000 for electron injection is formed on the electron injection layer 600 by a method such as a vacuum deposition method or a sputtering method. Various metals may be used as the cathode. Specific examples include materials such as aluminum, gold, silver, and magnesium.

The organic light emitting device of the present invention may have an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and an organic light emitting device having a cathode structure, as well as an organic light emitting device having various structures. It is also possible to further form a layer or an intermediate layer of two layers.

As described above, the thickness of each organic material layer formed according to the present invention can be adjusted according to the required degree, and specifically, it may be 10 to 1,000 nm, and more specifically, it may be 20 to 150 nm.

According to one embodiment of the present invention, in the anode 1000, the capping layer 3000 may be formed on the outside of the electrode in which the hole injection layer 200 is interposed. In addition, in the cathode 3000 electrode, the cap pip layer 3000 may be formed on the outside of the electrode in which the electron injection layer 600 is interposed. Although not limited thereto, the capping layer 3000 may be formed by a deposition process, and may be formed to a thickness of 300 to 900 Å.

In the organic light emitting device according to the present aspect, all of the contents described in the first aspect of the present application may be applied, and the present disclosure may not be limited thereto.

Hereinafter, it will be described in more detail through Examples of the present application, and the scope of the present application is not limited by the Examples.

[Example]

intermediate synthesis

For the synthesis of the target compound, the intermediate OP may be synthesized by the following reaction scheme.

Preparation Example 1 : Intermediate (OP1)

30.0 g of 2-bromo-9,9-diphenyl-9H-fluorene, 5.6 g of aniline, 11 g of t-BuONa, 2.8 g of Pd ₂ (dba) ₃ , and 3.5 ml of (t-Bu) ₃ P3.5 ml of toluene in a round-bottom flask It was dissolved in 500ml and stirred under reflux. The reaction was confirmed by TLC, and the reaction was terminated after addition of water. The organic layer was extracted with MC, filtered under reduced pressure, and recrystallized to obtain 21.3 g of OP1 (yield 69%).

In the same manner as for OP1, OP2 to OP8 as follows were synthesized by different starting materials as shown in Table 1 below.

Starting material for OP2 Starting material for OP3 Starting material for OP4

,

,

,

,

2-bromo-9,9-diphenyl-9H-fluorene, naphthalen-1-amine 2-bromo-9,9-diphenyl-9H-fluorene, naphthalen-2-amine 2-bromo-9,9-diphenyl-9H-fluorene, [1,1'-biphenyl]-4-amine Starting material for OP5 Starting material for OP6 Starting material for OP7

,

,

,

3-bromo-9,9-diphenyl-9H-fluorene, aniline 4-bromo-9,9-diphenyl-9H-fluorene, [1,1'-biphenyl]-2-amine 2,7-dibromo-9,9-diphenyl-9H-fluorene, N-phenyl-[1,1'-biphenyl]-4-amine Starting material for OP8

,

2,7-dibromo-9,9-diphenyl-9H-fluorene, di([1,1'-biphenyl]-4-yl)amine

compound synthesis

By using the intermediates OP1 to OP8, target compounds 1 to 15 were synthesized as follows.

Synthesis of compound 1

In a round bottom flask, 3.0 g of the 3-(4-bromophenyl)-9-phenyl-9H-carbazole, 3.1 g of OP1, 1.1 g of t-BuONa, 0.3 g of Pd ₂ (dba) ₃ , and 0.3 g of (t-Bu) ₃ P0. 3 ml was dissolved in 100 ml of toluene and stirred under reflux. The reaction was confirmed by TLC, and the reaction was terminated after addition of water. The organic layer was extracted with MC, filtered under reduced pressure, and recrystallized to obtain 3.5 g of Compound 1 (yield 64%). m/z: 726.30 (100.0%), 727.31 (59.9%), 728.31 (17.6%), 729.31 (3.4%)

Synthesis of compound 2

In the same manner as in Compound 1, Compound 2 was synthesized using OP2 instead of OP1. (Yield 65%) m/z: 776.32 (100.0%), 777.32 (64.6%), 778.33 (20.3%), 779.33 (4.2%)

Synthesis of compound 3

In the same manner as in Compound 1, Compound 3 was synthesized using OP3 instead of OP1. (Yield 60%) m/z: 776.32 (100.0%), 777.32 (64.6%), 778.33 (20.3%), 779.33 (4.2%)

Synthesis of compound 4

Compound 4 was synthesized using OP4 instead of OP1 in the same manner as in Compound 1. (Yield 70%) m/z: 802.33 (100.0%), 803.34 (66.5%), 804.34 (22.2%), 805.34 (4.7%)

Synthesis of compound 5

In the same manner as in Compound 1, 3-(4'-bromo-[1,1'-biphenyl]-4-yl)-9-phenyl-9H instead of 3-(4-bromophenyl)-9-phenyl-9H-carbazole Compound 5 was synthesized using -carbazole. (Yield 63%) m/z: 802.33 (100.0%), 803.34 (66.5%), 804.34 (22.2%), 805.34 (4.7%)

Synthesis of compound 6

In the same manner as in Compound 1, 3-(4'-bromo-[1,1'-biphenyl]-4-yl)-9-phenyl instead of 3-(4-bromophenyl)-9-phenyl-9H-carbazole and OP1 Compound 6 was synthesized using -9H-carbazole and OP2. (Yield 60%) m/z: 852.35 (100.0%), 853.35 (71.0%), 854.36 (24.7%), 855.36 (5.7%)

Synthesis of compound 7

In the same manner as in Compound 1, 3-(4'-bromo-[1,1'-biphenyl]-4-yl)-9-phenyl instead of 3-(4-bromophenyl)-9-phenyl-9H-carbazole and OP1 Compound 7 was synthesized using -9H-carbazole and OP3. (Yield 62%) m/z: 852.35 (100.0%), 853.35 (71.0%), 854.36 (24.7%), 855.36 (5.7%)

Synthesis of compound 8

In the same manner as in Compound 1, 3-(4'-bromo-[1,1'-biphenyl]-4-yl)-9-phenyl instead of 3-(4-bromophenyl)-9-phenyl-9H-carbazole and OP1 Compound 8 was synthesized using -9H-carbazole and OP4. (Yield 65%) m/z: 878.37 (100.0%), 879.37 (73.0%), 880.37 (26.4%), 881.38 (6.2%), 882.38 (1.1%)

Synthesis of compound 9

In the same manner as in Compound 1, 3-(4''-bromo-[1,1':4',1''-terphenyl]-4- instead of 3-(4-bromophenyl)-9-phenyl-9H-carbazole Compound 9 was synthesized using yl)-9-phenyl-9H-carbazole. (Yield 58%) m/z: 878.37 (100.0%), 879.37 (73.0%), 880.37 (26.4%), 881.38 (6.2%), 882.38 (1.1%)

Synthesis of compound 10

In the same manner as in Compound 1, Compound 10 was synthesized using OP5 instead of OP1. (Yield 60%) m/z: 726.30 (100.0%), 727.31 (59.9%), 728.31 (17.6%), 729.31 (3.4%)

Synthesis of compound 11

In the same manner as in Compound 1, 3-(4'-bromo-[1,1'-biphenyl]-4-yl)-9-phenyl instead of 3-(4-bromophenyl)-9-phenyl-9H-carbazole and OP1 Compound 11 was synthesized using -9H-carbazole and OP5. (Yield 63%) m/z: 802.33 (100.0%), 803.34 (66.5%), 804.34 (22.2%), 805.34 (4.7%)

Synthesis of compound 12

Compound 12 was synthesized using OP6 instead of OP1 in the same manner as in Compound 1. (Yield 58%) m/z: 726.30 (100.0%), 727.31 (59.9%), 728.31 (17.6%), 729.31 (3.4%)

Synthesis of compound 13

In the same manner as in Compound 1, 3-(4'-bromo-[1,1'-biphenyl]-4-yl)-9-phenyl instead of 3-(4-bromophenyl)-9-phenyl-9H-carbazole and OP1 Compound 13 was synthesized using -9H-carbazole and OP6. (Yield 60%) m/z: 802.33 (100.0%), 803.34 (66.5%), 804.34 (22.2%), 805.34 (4.7%)

Synthesis of compound 14

In the same manner as in Compound 1, Compound 14 was synthesized using 3-bromo-9-phenyl-9H-carbazole and OP7 instead of 3-(4-bromophenyl)-9-phenyl-9H-carbazole and OP1. (Yield 65%) m/z: 802.33 (100.0%), 803.34 (66.5%), 804.34 (22.2%), 805.34 (4.7%)

Synthesis of compound 15

In the same manner as in Compound 1, Compound 15 was synthesized using 3-bromo-9-phenyl-9H-carbazole and OP8 instead of 3-(4-bromophenyl)-9-phenyl-9H-carbazole and OP1. (Yield 67%) m/z: 878.37 (100.0%), 879.37 (73.0%), 880.37 (26.4%), 881.38 (6.2%), 882.38 (1.1%)

Organic light emitting device manufacturing

Example 1

After forming a hole injection layer HI01 600 Å, HATCN 50 Å, and BPA 600 Å as a hole transport layer on an ITO substrate on which a reflective layer containing Ag was formed, the light emitting layer was doped with BH01:BD01 3% to form a film of 250 Å. Next, 300 Å of Alq3:Liq (1:1) was formed as an electron transport layer, and then 10 Å of LiF was deposited to form an electron injection layer. Subsequently, MgAg was deposited to a thickness of 15 nm as a cathode, and Compound 1 was deposited to a thickness of 600 Å as a capping layer on the cathode. An organic light emitting device was manufactured by encapsulating the device in a glove box.

Examples 2 to 15

An organic light emitting diode was manufactured in the same manner as in Example 1, except that the capping layer was formed by using each of Compounds 2 to 15 instead of Compound 1 in Example 1.

Comparative Examples 1 to 7

An organic light emitting diode was manufactured in the same manner as in Example 1, except that a capping layer was formed by using each of the following compounds Ref.1 to Ref.7 instead of Compound 1 in Example 1.

[Performance evaluation of organic light-emitting devices]

Electrons and holes are injected by applying voltage with a Kiethley 2400 source measurement unit, and the luminance when light is emitted is measured using a Konica Minolta spectroradiometer (CS-2000). By doing so, the performance of the organic light emitting devices of Examples and Comparative Examples was evaluated by measuring current density and luminance with respect to applied voltage under atmospheric pressure conditions, and the results are shown in [Table 2] below.

Op. V mA/cm2 Cd/A QE (%) CIEy CIEy LT97 Example 1 4.00 10 8.60 7.51 0.139 0.060 140 Example 2 4.00 10 8.58 7.45 0.140 0.061 138 Example 3 4.00 10 8.57 7.43 0.140 0.061 138 Example 4 4.00 10 8.73 7.60 0.139 0.060 147 Example 5 3.99 10 8.65 7.50 0.138 0.061 140 Example 6 4.00 10 8.70 7.56 0.140 0.061 140 Example 7 3.99 10 8.60 7.47 0.140 0.060 140 Example 8 3.99 10 8.62 7.50 0.140 0.061 138 Example 9 4.00 10 8.82 7.75 0.140 0.060 150 Example 10 3.99 10 8.75 7.65 0.140 0.060 142 Example 11 4.00 10 8.73 7.65 0.139 0.060 140 Example 12 4.01 10 8.70 7.67 0.140 0.060 147 Example 13 3.99 10 8.70 7.60 0.139 0.060 140 Example 14 4.00 10 8.52 7.28 0.140 0.060 139 Example 15 4.00 10 8.50 7.29 0.140 0.061 141 Comparative Example 1 4.00 10 7.30 6.00 0.143 0.070 105 Comparative Example 2 4.02 10 6.85 5.95 0.143 0.071 100 Comparative Example 3 4.01 10 6.90 5.34 0.144 0.075 92 Comparative Example 4 4.01 10 7.00 5.60 0.144 0.074 88 Comparative Example 5 4.00 10 6.60 5.85 0.143 0.070 62 Comparative Example 6 4.01 10 6.63 5.43 0.145 0.078 60 Comparative Example 7 4.01 10 6.50 5.43 0.145 0.078 80

As shown in Table 1, it can be seen that the Examples of the present invention exhibit high external luminous efficiency, and greatly improve color purity and lifespan compared to Comparative Examples 1 to 7.

More specifically, as compared to Comparative Examples 1 to 4, the examples of the present invention are substituted at the 3 position of carbazole, an additional arylene linkage is bonded between the nitrogen of the carbazole and arylamine, and carbazole and arylamine It can be seen that the nitrogen of the arylene linker is connected at the para position to maintain a large bandgap, and can have a high refractive index, thereby improving efficiency and color coordinates. In addition, as compared to Comparative Examples 5 and 6 having alkylfluorene and Comparative Example 7 not having fluorene, Examples of the present invention include diarylfluorene having py-conjugation, molecular arrangement and intermolecular packing This can be excellent. In addition, due to the diarylfluorene, it has high Tg and Td even at a relatively low molecular weight, so recrystallization of the thin film can be suppressed, and thermal stability can be excellent.

That is, it was confirmed that when the capping layer is formed on the organic light emitting device using the compound for forming a capping layer according to an embodiment of the present invention, external luminous efficiency, color coordinates and lifespan of the organic light emitting device can be improved.

The above description of the present application is for illustration, and those of ordinary skill in the art to which the present application pertains will understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present application. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may also be implemented in a combined form.

The scope of the present application is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims, and their equivalents should be construed as being included in the scope of the present application. .

100: substrate
200: hole injection layer
300: hole transport layer
400: light emitting layer
500: electron transport layer
600: electron injection layer
1000: anode (first electrode)
2000: cathode (second electrode)
3000: capping layer

Claims (9)

A compound for forming a capping layer represented by the following Chemical Formula 3:
[Formula 3]

In Formula 3,
Ar ₁ and Ar ₂ are each independently a substituted or unsubstituted C _6-50 aryl group, or a substituted or unsubstituted C _5-50 heteroaryl group,
Ar ₃ and Ar ₄ are each independently a substituted or unsubstituted C _{6 to 37} aryl group, or a substituted or unsubstituted C _{5 to 37} heteroaryl group,
R ₁ to R ₃ are each independently hydrogen, deuterium, a substituted or unsubstituted C _1-30 alkyl group, a substituted or unsubstituted C _1-30 alkoxy group, or a substituted or unsubstituted C _2-30 alkenyl group , a substituted or unsubstituted C _6-50 aryl group, or a substituted or unsubstituted C _5-50 heteroaryl group,
R ₄ and R ₅ are each independently hydrogen, deuterium, a substituted or unsubstituted C _{1 to 37} alkyl group, a substituted or unsubstituted C _{1 to 37} alkoxy group, or a substituted or unsubstituted C _{2 to 37} alkenyl group , a substituted or unsubstituted C _{6 to 37} aryl group, or a substituted or unsubstituted C _{5 to 37} heteroaryl group,
L ₁ and L ₂ are each independently a direct bond, a substituted or unsubstituted C _{6 ~ 37} arylene group, or a substituted or unsubstituted C _{5 ~ 37} heteroarylene group,
l is an integer from 0 to 4, m is an integer from 0 to 3,
n', and o' are each independently an integer from 0 to 3. delete According to claim 1,
The compound is a compound for forming a capping layer represented by the following formula (5):
[Formula 5]

In Formula 5,
R ₆ and R ₇ are each independently hydrogen, deuterium, a substituted or unsubstituted C _1-25 alkyl group, a substituted or unsubstituted C _1-25 alkoxy group, or a substituted or unsubstituted C _2-25 alkenyl group , a substituted or unsubstituted C _6-25 aryl group, or a substituted or unsubstituted C _5-25 heteroaryl group,
p and q are each independently an integer from 0 to 5; 4. The method of claim 3,
The compound is a compound for forming a capping layer represented by the following Chemical Formula 7:
[Formula 7]

In Formula 7,
t, and u are each independently an integer of 0 to 3. delete According to claim 1,
Ar ₁ and Ar ₂ are each independently phenyl, naphthyl, biphenyl, terphenyl, fluorenyl, or a combination thereof. According to claim 1,
The compound for forming the capping layer is any one of the following compounds for forming the capping layer:

first and second electrodes;
an organic material layer interposed inside the first and second electrodes; and
It is disposed on the outside of any one of the first and second electrodes and contains the compound for forming a capping layer according to any one of claims 1, 3, 4, 6, and 7 An organic light-emitting device comprising a capping layer. 9. The method of claim 8,
The capping layer has a thickness of 300 to 900 Å.

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