KR20200062616A - Organic compound for capping layer and organic electroluminescent divice including the same - Google Patents

Abstract

The present application relates to a compound for a capping layer, and an organic light emitting device comprising the same. The compound for the capping layer according to an embodiment of the present invention is applied to the organic light emitting device to improve external light emission efficiency, color coordinates, and lifespan of the organic light emitting device. The present invention provides the compound for the capping layer represented by chemical formula 1.

Description

Organic compound for capping layer and organic light emitting device including same {ORGANIC COMPOUND FOR CAPPING LAYER AND ORGANIC ELECTROLUMINESCENT DIVICE INCLUDING THE SAME}

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

Materials used as an organic material layer in the organic light emitting device can be largely classified into light emitting materials, hole injection materials, hole transport materials, electron transport materials, and electron injection materials depending on their function. Further, the light emitting material may be classified into a fluorescent material derived from the singlet excited state of the electron or a phosphorescent material derived from the triplet excited state of the electron according to the light emission mechanism. In addition, it can be divided into blue, green, and red emitting materials according to the emitting color.

In general organic light emitting devices, 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. Here, the hole transport layer, the light emitting layer and the electron transport layer are organic thin films made of an organic compound.

The driving principle of the organic light emitting device having the structure as described above is as follows. When a voltage is applied between the anode and the cathode, holes injected from the anode move to the light emitting layer via the hole transport layer, and electrons injected from the cathode move to the light emitting layer via the electron transport layer. The 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 device can be generally divided into internal light emission efficiency and external light emission efficiency. The internal luminous efficiency is related to how efficiently excitons are generated and photoconversion is performed in the organic material layer interposed between the first electrode and the second electrode, such as a hole transport layer, a light emitting layer, and an electron transport layer. 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 represents the efficiency at which the light generated in the organic material layer 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.

Various organic compounds have been applied as a capping layer in order to prevent total external light from being lost due to the external light emission efficiency, that is, a method for increasing light extraction, 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 No. 10-2004-0098238

The problem to be solved by the present application is a compound for a capping layer capable of improving the color purity and the external luminous efficiency of an organic light emitting device by having a high refractive index while having a wide band gap that cannot absorb the visible light region, and containing the compound It is to provide an organic light emitting device including a capping layer.

Another problem to be solved by the present application is a compound for a capping layer capable of increasing the efficiency by improving the refractive index and improving the stability from exposure to external ultraviolet rays through increasing the absorption wavelength in the ultraviolet region, and the It is to provide an organic light emitting device including a capping layer containing a compound.

Another problem to be solved by the present application is to increase the conjugation in the compound to improve the thin film arrangement of the molecules to form a stable thin film to prevent the external air and moisture to improve the life of the organic light emitting device through a capping layer compound, and It is to provide an organic light emitting device including a capping layer containing the compound.

Another problem to be solved by the present application is to have a high Tg and a high Td to prevent intermolecular recrystallization to keep a stable thin film from the heat generated when driving the organic light emitting device, and a cap for the capping layer containing the compound It is to provide an organic light emitting device including a ping layer.

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.

The first aspect of the present application provides a compound for a capping layer represented by Formula 1 below:

[Formula 1]

In Chemical Formula 1,

X is O or S,

Y is O, S or CR`R,

R`, R``, R <sub>1</sub> to R <sub>4</sub> are each independently hydrogen, deuterium, a halogen, a nitro group, a nitrile group, a substituted or unsubstituted C <sub>1 ~ 30</sub> alkyl group, a substituted or unsubstituted C <sub>2 ~ 30</sub> alkenyl group , substituted or unsubstituted C <sub>1 ~ 30</sub> alkoxy group, a substituted or unsubstituted C <sub>1 ~ 30</sub> sulfide group, a substituted or unsubstituted C <sub>6 ~ 50</sub> aryl group, or a substituted or unsubstituted C <sub>2 ~ 50</sub> hetero aryl group, And (where R` and R`` may combine with each other to form a ring or not),

l and o are each independently 0 or an integer from 1 to 4,

m and n are each independently 0 or an integer from 1 to 3,

L ₁ and L ₂ are each independently a substituted or unsubstituted C _{6 ~ 50} aryl group, or a substituted or unsubstituted C _{2 ~ 50} hetero arylene group,

Ar ₁ is either one of a substituted or unsubstituted C _{6 ~ 50} aryl group, a substituted or unsubstituted C _{2 ~ 50} hetero arylene group, or combinations thereof (however, L ₁ and L ₂ is at least C _16, L _{When 1} and L ₂ are both C ₁₀ or more aryl groups, Ar ₁ may be a phenyl group).

The second aspect of the present application includes a first electrode and a second electrode; An organic material layer interposed inside the first electrode and the second electrode; And a capping layer disposed outside any one or more of the first and second electrodes, and containing a compound for a capping layer according to the first aspect of the present application. It provides an organic light emitting device comprising a.

Compound for a capping layer according to an embodiment of the present invention has a wide band gap that can not absorb the visible region of the organic light emitting device and at the same time has a high refractive index to improve the color purity and external luminous efficiency of the organic light emitting device It shows effect.

In addition, the compound for a capping layer according to an embodiment of the present invention may have an improved refractive index to improve efficiency, and increase the absorption wavelength in the ultraviolet region to improve stability from exposure to external ultraviolet rays to increase life. It shows the effect of action.

In addition, the compound for a capping layer according to an embodiment of the present invention can increase the conjugation in a compound to improve the thin film arrangement of molecules to form a stable thin film to improve the life of the organic light emitting device through blocking external air and moisture. It shows the effect of action.

In addition, the compound for a capping layer according to an embodiment of the present invention has a high Tg and a high Td to prevent recrystallization between molecules, thereby exhibiting an effect of maintaining a stable thin film from heat generated when driving the organic light emitting device.

1 shows a schematic diagram of an organic light emitting device according to an embodiment of the present application.
2 is a graph comparing the absorption strength of a compound according to an embodiment of the present application and a compound of a comparative example in the ultraviolet region.

Hereinafter, embodiments and examples of the present application will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains may easily practice.

However, the present application may be implemented in various different forms, and is not limited to the embodiments and examples described herein. In addition, in order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and like reference numerals are assigned to similar parts throughout the specification.

Throughout this specification, when one member is positioned “on” another member, this includes not only the case where one member abuts another member, but also the case where another member exists between the two members.

Throughout the present specification, when a part “includes” a certain component, it means that the component may further include other components, not to exclude other components, unless otherwise stated. The terms "about", "substantially", and the like, as used throughout this specification, are used in or at a value close to that value when manufacturing and material tolerances specific to the stated meaning are given, and are understood herein. To aid, accurate or absolute figures are used to prevent unscrupulous use of the disclosed disclosure by unscrupulous infringers. The term “~(step)” or “step of” as used in the present specification does not mean “step for”.

Throughout the present specification, the term “combination of these” included in the expression of the marki form means one or more mixtures or combinations selected from the group consisting of the components described in the expression of the marki form, the component. It means to include one or more selected from the group consisting of.

Throughout this specification, the description of “A and/or B” means “A or B, or A and B”.

Throughout this specification, the term “aryl” or “arylene” refers to a C _6-50 aromatic hydrocarbon ring group such as phenyl, benzyl, naphthyl, biphenyl, terphenyl, fluorenyl, phenanthrenyl, tri Means to include aromatic rings such as phenylenyl, perenyl, chrysenyl, fluoranthenyl, benzofluorenyl, benzotriphenylenyl, benzocristenyl, anthracenyl, stilbenyl, pyrenyl, and the term "hetero aryl "or" heteroarylene "is a C _{2 ~ 50} aromatic ring containing at least one hetero atom, for example, pyrrolyl, pyrazinyl, pyridinyl, indolyl, isoindolyl, furyl, benzofuranyl , Isobenzofuranyl, dibenzofuranyl, benzothiophenyl, dibenzothiophenyl, quinolyl, 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, thiophene ring, oxazole ring, oxadiazole ring, benzoxazole ring, thiazole ring, thiadiazole ring, benzothiazole ring, triazole ring, imidazole ring, benzo It may mean to include a heterocyclic group formed from an imidazole ring, a pyran ring, a dibenzofuran ring.

The term throughout the present specification, "substituted" or "which may be substituted" is heavy hydrogen, a halogen, an amino group, a nitrile group, a nitro group or a C ₁ ~ ₃₀ alkyl group, C ₂ ~ ₃₀ alkenyl, C ₁ ~ ₃₀ alkoxy group, C _It may mean that it may be substituted with one or more groups selected from the group consisting of ₃ to ₂₀ cycloalkyl groups, C ₃ to ₂₀ heterocycloalkyl groups, C ₆ to ₃₀ aryl groups and C ₂ to ₃₀ heteroaryl groups. In addition, the same symbols throughout the present specification may have the same meanings unless otherwise specified.

The first aspect of the present application provides a compound for a capping layer represented by Formula 1 below:

[Formula 1]

In Chemical Formula 1,

X is O or S,

Y is O, S or CR`R,

R`, R``, R <sub>1</sub> to R <sub>4</sub> are each independently hydrogen, deuterium, a halogen, a nitro group, a nitrile group, a substituted or unsubstituted C <sub>1 ~ 30</sub> alkyl group, a substituted or unsubstituted C <sub>2 ~ 30</sub> alkenyl group , substituted or unsubstituted C <sub>1 ~ 30</sub> alkoxy group, a substituted or unsubstituted C <sub>1 ~ 30</sub> sulfide group, a substituted or unsubstituted C <sub>6 ~ 50</sub> aryl group, or a substituted or unsubstituted C <sub>2 ~ 50</sub> hetero aryl group, And (where R` and R`` may combine with each other to form a ring or not),

l and o are each independently 0 or an integer from 1 to 4,

m and n are each independently 0 or an integer from 1 to 3,

L ₁ and L ₂ are each independently a substituted or unsubstituted C _{6 ~ 50} aryl group, or a substituted or unsubstituted C _{2 ~ 50} hetero arylene group,

Ar ₁ is either one of a substituted or unsubstituted C _{6 ~ 50} aryl group, a substituted or unsubstituted C _{2 ~ 50} hetero arylene group, or combinations thereof (however, L ₁ and L ₂ is at least C _16, L _{When 1} and L ₂ are both C ₁₀ or more aryl groups, Ar ₁ may be a phenyl group).

The compound for the capping layer of Formula 1 according to an embodiment of the present invention is a tricyclic ring conjugated to one side (dibenzofuran or dibenzothiophene) conjugated to one side centered on an amine, and conjugated to the other side (Dibenzofuran, dibenzothiophene or fluorene) has a linking group such as arylene or heteroarylene between the tricyclic rings and the amine at the same time as it is bonded, so a wide band gap that cannot absorb the visible region And can maintain a high refractive index. Through these properties, the compound for a capping layer of the present application can improve the color purity and external luminous efficiency of the organic light emitting device.

In addition, the compound for capping layer of Chemical Formula 1 according to an embodiment of the present invention can improve the refractive index through expansion through an arylene or heteroarylene linker, and at the same time increase the absorption wavelength in the ultraviolet region, through which external ultraviolet rays Stability can be improved from exposure. Through these properties, the compound for the capping layer of the present application can improve the external luminous efficiency of the organic light emitting device and prolong its life.

The compound for a capping layer of Formula 1 according to an embodiment of the present invention may have a refractive index of 450 nm or more, and specifically 2.2 or more. In addition, the absorption intensity at 380 nm, which is the ultraviolet absorption region, may be 0.6 or more, specifically 0.7 or more.

In addition, the compound for the capping layer of Chemical Formula 1 according to an embodiment of the present invention can form a stable thin film due to excellent thin film arrangement of molecules due to increased conjugation through expansion through an arylene or heteroarylene linking group. Through these characteristics, it is possible to improve the life of the organic light emitting device through blocking of external air and moisture.

In addition, the compound for the capping layer of Formula 1 according to an embodiment of the present invention is a tricyclic ring (dibenzofuran or dibenzothiophene) conjugated to one side and a tricyclic ring (di Due to the combination of benzofuran, dibenzothiophene, or fluorene), it has high Tg and high Td to suppress intermolecular recrystallization, and through this, generation during operation can maintain a stable thin film from heat.

That is, when the compound for a capping layer according to an embodiment of the present invention is applied to the capping layer, the external luminous efficiency can be improved by disposing the capping layer outside the electrode of the organic light emitting device. When light generated from the organic material layer interposed inside the first electrode and the second electrode of the organic light emitting device is extracted to the outside of the organic light emitting device, it is possible to prevent the light going outward from being totally reflected and lost.

The compound for a capping layer according to an embodiment of the present invention may have a high refractive index due to the above structural characteristics, and has excellent thin film stability, and when applied as a capping layer of an organic light emitting device, the external light emitting efficiency, color coordinate of the organic light emitting device and Life can be improved.

In one embodiment of the present invention, Formula 1 may be represented by Formula 2 below.

[Formula 2]

In Chemical Formula 2,

X, Y, R`, R``, R ₁ to R ₄ , l, m, n, o and Ar ₁ are as defined in Chemical Formula 1,

R ₅ and R ₆ are each independently a hydrogen, a deuterium, a halogen, a nitro group, a nitrile group, a substituted or unsubstituted C _{1 ~ 30} alkyl group, a substituted or unsubstituted C _{2 ~ 30} alkenyl group, a substituted or unsubstituted C _{1 to 30} and an alkoxy group, a substituted or unsubstituted C _1-30 sulfide group, a substituted or unsubstituted C _{6 ~ 50} aryl group, or a substituted or unsubstituted C _{2 ~ 50} hetero aryl group,

p and q are each independently an integer of 1-4.

In one embodiment of the present invention, Formula 1 may be represented by Formula 3 below.

[Formula 3]

In Chemical Formula 3,

X, Y, R`, R``, R ₁ to R ₄ , l, m, n, o and Ar ₁ are as defined in Chemical Formula 1,

p and q are each independently an integer of 1-4.

In one embodiment of the present invention, Formula 1 may be represented by Formula 4 below.

[Formula 4]

In Chemical Formula 4,

X, Y, R`, R``, R ₁ to R ₄ , l, o and Ar ₁ are as defined in Chemical Formula 1,

m and n are each independently 0, 1 or 2,

p and q are each independently an integer of 1-4.

In one embodiment of the present invention, Formula 1 may be represented by Formula 5 below.

[Formula 5]

In Chemical Formula 5,

X, Y, R`, R``, R ₁ to R ₄ , l and o are as defined in Chemical Formula 1,

m and n are each independently 0, 1 or 2,

p and q are each independently an integer from 1 to 4,

Ar ₂ is a substituted or unsubstituted C _{6 to 44} arylene group, a substituted or unsubstituted C _{2 to 44} heteroarylene group, or a combination thereof.

In one embodiment of the present invention, Formula 1 may be represented by Formula 6 below.

[Formula 6]

In Chemical Formula 6,

X, Y, R`, R``, R ₁ to R ₄ , l and o are as defined in Chemical Formula 1,

m and n are each independently 0, 1 or 2,

p and q are each independently an integer of 1 to 4, and the sum of p and q is an integer of 4 or more.

According to an embodiment of the present invention, in Formulas 2 to 6, p and q are each independently an integer of 1, 2 or 3, and more specifically, at least one of p and q may be an integer of 2 or 3 . In this case, the life of the organic light emitting device can be greatly increased.

The compound represented by Formulas 2 to 6 is a tricyclic ring (dibenzofuran or dibenzothiophene) conjugated to one side and a conjugated tricyclic ring (dibenzone) to the other side as in the compound of Formula 1 Furan, dibenzothiophene or fluorene) has a linkage, and has a linking group such as arylene or heteroarylene between amines.

Therefore, the compounds represented by Formulas 2 to 6 can also maintain a wide band gap that cannot absorb the visible region, can maintain a high refractive index, improve the refractive index, and at the same time increase the absorption wavelength in the ultraviolet region. Stability can be improved from exposure to external UV rays, and the conjugation is increased to form a stable thin film due to excellent thin film arrangement of molecules, and high Tg and high Td to suppress recrystallization between molecules. Through these properties, the organic light emitting device including the capping layer containing the compound for a capping layer of the present application has improved color purity and external luminous efficiency, and improved stability from moisture and heat, thereby extending its life.

According to an embodiment of the present invention, in Formula 1, X and Y may each independently be O or S. That is, the tricyclic ring may be dibenzofuran or dibenzothiophene. In this case, the efficiency of the organic light emitting device can be further improved, and the life can be further increased.

In addition, according to an embodiment of the present invention, in Formula 1, R ₁ to R ₄ may each independently be hydrogen, methyl, fluoro, methoxy, cyano, phenyl, or biphenyl. In this case, it is possible to maintain a wide band gap by minimizing the pi-conjugation of the substituent.

In addition, according to an embodiment of the present invention, in Formula 1, R` and R″ may each independently be hydrogen or methyl. In this case, it is effective to improve the refractive index by minimizing the bulky properties of fluorene.

In addition, according to an embodiment of the present invention, in Formula 2, R ₅ and R ₆ may be hydrogen at the same time. In this case, it is effective to improve the refractive index by minimizing the bulky characteristics of the connector.

In addition, according to an embodiment of the present invention, Ar ₁ may be naphthyl, biphenyl, terphenyl, phenanthrenyl, triphenylenyl, dibenzofuranyl, dibenzothiophenyl, pyridinyl, or a combination thereof. . In this case, it is effective to increase the absorption wavelength in the ultraviolet region.

In addition, according to an embodiment of the present invention, Ar ₂ is phenyl, naphthyl, biphenyl, terphenyl, phenanthrenyl, triphenylenyl, dibenzofuranyl, dibenzothiophenyl, pyridinyl, or a combination thereof. Can be.

Further, according to an embodiment of the present invention, Ar ₂ may include dibenzofuranyl or dibenzothiophenyl. In this case, the binding energy between carbon, O, and S atoms is higher, so that the molecule is excellent in stability, and at the same time, absorption of the visible region can be minimized.

In one embodiment of the present invention, the compound for capping layers represented by Formulas 1 to 6 may be synthesized by the following reaction scheme, but is not limited thereto, and may also be synthesized by various methods.

[Reaction formula]

In one embodiment of the present invention, the compound represented by Chemical Formula 1 may be any one of Compounds 1 to 588 shown below, but may not be limited thereto:

The 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 Chemical Formulas 1 to 6 is disposed.

According to an embodiment of the present invention, the organic light emitting device includes a first electrode and a second electrode; An organic material layer interposed inside the first electrode and the second electrode; And a capping layer disposed outside any one or more of the first electrode and the second electrode, and containing a compound for a capping layer according to the present application. Here, the side adjacent to the organic material layer interposed between the first electrode and the second electrode among both side surfaces 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 an embodiment of the present invention, the organic light emitting device may have various organic material layers interposed inside the first electrode and the second electrode, and a capping layer may be formed outside of at least one of the first and second electrodes. . The capping layer may be formed on both the outside of the first electrode and the outside of the second electrode, or may be disposed outside the first electrode or outside the second electrode. The capping layer may include a compound for a capping layer according to the present invention.

Further, according to an embodiment of the present invention, an organic material layer having various functions may be additionally formed on the outsides of the first and second electrodes with the capping layer interposed therebetween. That is, the capping layer is directly formed on the outer surface of the first electrode (or the second electrode), or the organic material layer having various functions is formed on the outer surface of the first electrode (or the second electrode). 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 one embodiment of the present invention alone, or may include two or more or known compounds together.

The organic light emitting diode according to the exemplary embodiment of the present invention includes at least one layer of an organic material between the first electrode and the second electrode, that is, inside the first electrode and the second electrode, and outside the first electrode and the second electrode. A capping layer may be formed. The organic material layer may be a hole transport layer, a light emitting layer, and an electron transport layer constituting a light emitting unit, 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 the first electrode (anode, anode) and the second electrode (cathode, cathod) An organic material layer constituting a light emitting unit such as a layer (EIL) may be included in one or more layers.

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

As described above, the compound for a capping layer according to an embodiment of the present invention has a tricyclic ring (dibenzofuran or dibenzothiophene) conjugated to one side and a tricyclic ring (dibenzo) conjugated to the other side. Furan, dibenzothiophene or fluorene) has a linking group, such as arylene or heteroarylene, between the tricyclic rings and the amine, while maintaining a wide band gap that cannot absorb the visible region. It can maintain a high refractive index, improve the refractive index, and at the same time increase the absorption wavelength in the ultraviolet region, thereby improving stability from external UV exposure, and increase the conjugation to form a stable thin film with excellent molecular thin film arrangement. It is possible to suppress the intermolecular recrystallization by having high Tg and high Td. Accordingly, the organic light emitting device according to the present invention has improved color purity and external luminous efficiency, and improved stability from moisture and heat, thereby extending the life.

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

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

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

Next, a 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 cast method, and an LB method. In the case of forming the hole transport layer by the vacuum deposition method, the deposition conditions vary depending on the compound used, but it is generally preferable to select a range of conditions substantially the same as the formation of the hole injection layer.

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

The light emitting layer 400 may be deposited 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 cast method, or an LB method. In the case of forming the light emitting layer by the vacuum deposition method, the deposition conditions vary depending on the compound used, but it is generally preferable to select within the same range of conditions as the formation of the hole injection layer. In addition, the light emitting layer material can be used as a host or a dopant known compound.

In addition, when used together with a phosphorescent dopant in the light emitting layer, a hole suppressing material (HBL) may be additionally laminated by vacuum deposition or spin coating to prevent the triplet excitons or holes from diffusing into the electron transport layer. In this case, the hole-inhibiting material that can be used is not particularly limited, but any hole can be selected from known ones used as hole-inhibiting materials. For example, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, or hole inhibiting materials described in Japanese Patent Application Laid-Open No. 11-329734 (A1), and the like, typically include Balq (bis(8-hydr Hydroxy-2-methylquinolinolnato)-aluminum biphenoxide), phenanthrolines-based compounds (eg, UCP Corporation BCP (bassocuproin)), and the like can be used.

An electron transport layer 500 is formed on the light emitting layer 400 formed as described above, wherein the electron transport layer may be formed by a vacuum deposition method, a spin coating method, or a cast method. In addition, although the deposition conditions of the electron transport layer vary depending on the compound used, it is generally preferable to select within the same range of conditions as the formation of the hole injection layer.

Subsequently, an 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 vacuum-deposits, spin-coats, or casts the common electron injection layer material. 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.

The 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 can 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 is an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, an organic light emitting device having a cathode structure, as well as various structures of the organic light emitting device is possible, if necessary 1 It is also possible to further form a middle layer of two or two layers.

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

According to an embodiment of the present invention, the capping layer 3000 may be formed on the outside of the electrode in which the hole injection layer 200 is interposed in the anode 1000 electrode. In addition, a capping layer 3000 may be formed on the outside of the electrode in which the electron injection layer 600 is interposed in the cathode 3000 electrode. Although not limited thereto, the capping layer 3000 may be formed through a deposition process, and the thickness of the capping layer 3000 may be 100 to 1,000 mm 2, and more specifically 300 to 1,000 mm 2. In this case, it is possible to prevent the transmittance of the capping layer from lowering.

In the organic light emitting device according to this aspect, all of the contents described in the first aspect of the present application may be applied, and 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.

[Synthesis of intermediates]

To synthesize the target compound, an intermediate (Intermediate; IM) was synthesized through the following reaction scheme.

Preparation Example 1: Synthesis of IM1

To the round bottom flask, 5.0 g of the 4-(4-bromophenyl)dibenzo[b,d]furan, [1,1':4',1''-terphenyl]-4-amine, 4.2 g, t- 4.2 g of BuONa, 0.6 g of Pd ₂ (dba) ₃ , and 0.7 ml of (t-Bu) ₃ P were dissolved in 150 ml of toluene, followed by stirring at reflux. The reaction was confirmed by TLC, the reaction was terminated after adding water. The organic layer was extracted with MC, filtered under reduced pressure and recrystallized to obtain IM1 (5.4 g, yield 72%).

Preparation Examples 2 to 5: Synthesis of IM2 to IM5

In the same manner as in IM1, the starting materials were synthesized as shown in Table 1 below to synthesize IM2 to IM5 as follows.

Starting materials for IM2 Starting materials for IM3

2-(4-bromophenyl)dibenzo[b,d]furan,
[1,1':4',1''-terphenyl]-4-amine 2-(4-bromophenyl)dibenzo[b,d]furan,
4'-(dibenzo[b,d]furan-2-yl)-[1,1'-biphenyl]-4-amine Starting materials for IM4 Starting materials for IM5

2-(4-bromophenyl)dibenzo[b,d]furan,
4'-(dibenzo[b,d]thiophen-2-yl)-[1,1'-biphenyl]-4-amine 2-(4-bromophenyl)dibenzo[b,d]thiophene,
4'-(dibenzo[b,d]furan-2-yl)-[1,1'-biphenyl]-4-amine

[Synthesis of compound for capping layer]

Example 1: Synthesis of Compound 40

Round bottom flask with 4-(4-bromophenyl)dibenzo[b,d]furan 3.0 g, IM1 4.5 g, t-BuONa 1.4 g, Pd ₂ (dba) ₃ 0.4 g, (t-Bu) ₃ P After dissolving 0.4 ml in 150 ml of toluene, the mixture was stirred under reflux. The reaction was confirmed by TLC, the reaction was terminated after adding water. The organic layer was extracted with MC, filtered under reduced pressure and recrystallized to obtain compound 40 (4.5 g, yield 67%).

m/z: 729.27 (100.0%), 730.27 (58.9%), 731.27 (17.4%), 732.28 (3.2%)

Example 2: Synthesis of Compound 10

Compound using IM2 and 2-(4-bromophenyl)dibenzo[b,d]furan instead of IM1 and 4-(4-bromophenyl)dibenzo[b,d]furan in the same manner as in Example 1. 10 was synthesized (yield 65%).

m/z: 729.27 (100.0%), 730.27 (58.9%), 731.27 (17.4%), 732.28 (3.2%)

Example 3: Synthesis of Compound 477

Compound using IM3 and 2-(4-bromophenyl)dibenzo[b,d]furan instead of IM1 and 4-(4-bromophenyl)dibenzo[b,d]furan in the same manner as in Example 1. 477 was synthesized (yield 63%).

m/z: 819.28 (100.0%), 820.28 (65.4%), 821.28 (21.6%), 822.29 (4.4%)

Example 4: Synthesis of Compound 478

Compound using IM4 and 2-(4-bromophenyl)dibenzo[b,d]furan instead of IM1 and 4-(4-bromophenyl)dibenzo[b,d]furan in the same manner as in Example 1. 478 was synthesized (yield 70%).

m/z: 835.25 (100.0%), 836.26 (65.4%), 837.26 (22.0%), 838.26 (4.9%), 837.25 (4.8%), 838.25 (3.0%), 836.25 (1.2%), 839.26 (1.0%) )

Example 5: Synthesis of Compound 479

In the same manner as in Example 1, IM3 and 2-(4-bromophenyl)dibenzo[b,d]thiophene were used instead of IM1 and 4-(4-bromophenyl)dibenzo[b,d]furan. Compound 479 was synthesized (yield 68%).

m/z: 835.25 (100.0%), 836.26 (65.4%), 837.26 (22.0%), 838.26 (4.9%), 837.25 (4.8%), 838.25 (3.0%), 836.25 (1.2%), 839.26 (1.0%) )

Example 6: Synthesis of Compound 480

In the same manner as in Example 1, IM5 and 2-(4-bromophenyl)dibenzo[b,d]thiophene were used instead of IM1 and 4-(4-bromophenyl)dibenzo[b,d]furan. Compound 480 was synthesized (yield 71%).

m/z: 851.23 (100.0%), 852.24 (65.4%), 853.24 (21.2%), 853.23 (10.3%), 854.23 (6.0%), 854.24 (5.0%), 855.23 (2.0%), 852.23 (2.0%) )

Example 7: Synthesis of Compound 481

In the same manner as in Example 1, IM4 and 2-(4-bromophenyl)dibenzo[b,d]thiophene were used instead of IM1 and 4-(4-bromophenyl)dibenzo[b,d]furan. Compound 481 was synthesized (yield 63%).

m/z: 851.23 (100.0%), 852.24 (65.4%), 853.24 (21.2%), 853.23 (10.3%), 854.23 (6.0%), 854.24 (5.0%), 855.23 (2.0%), 852.23 (2.0%) )

Example 8: Synthesis of Compound 517

IM5 and 2-(4'-bromo-[1,1'-biphenyl]-4- instead of IM1 and 4-(4-bromophenyl)dibenzo[b,d]furan in the same manner as in Example 1. 1) Compound 517 was synthesized using dibenzo[b,d]furan (yield 70%).

m/z: 911.29 (100.0%), 912.29 (72.7%), 913.29 (26.4%), 914.30 (5.9%), 913.28 (4.5%), 914.28 (3.2%), 915.29 (1.2%), 915.30 (1.2%) )

Example 9: Synthesis of Compound 519

IM4 and 2-(4'-bromo-[1,1'-biphenyl]-4- instead of IM1 and 4-(4-bromophenyl)dibenzo[b,d]furan in the same manner as in Example 1. 1) Compound 519 was synthesized using dibenzo[b,d]thiophene (yield 66%).

m/z: 927.26 (100.0%), 928.27 (71.9%), 929.27 (26.8%), 929.26 (9.3%), 930.26 (6.6%), 930.27 (6.5%), 931.27 (2.5%), 928.26 (2.0%) ), 931.28 (1.0%)

Example 10: Synthesis of Compound 355

IM2 and 3-(4-bromophenyl)-9,9-dimethyl-9H-fluorene instead of IM1 and 4-(4-bromophenyl)dibenzo[b,d]furan in the same manner as in Example 1. Compound 355 was synthesized using (Yield 60%).

m/z: 755.32 (100.0%), 756.32 (62.1%), 757.33 (19.0%), 758.33 (3.9%)

[Production of Organic Light-Emitting Element]

An organic light emitting device was manufactured according to the structure shown in FIG. 1. The organic light emitting device is an anode from the bottom (hole injection electrode 1000) / hole injection layer 200 / hole transport layer 300 / light emitting layer 400 / electron transport layer 500 / cathode (electron injection electrode 2000) / The capping layers 3000 are stacked in this order.

In FIG. 1, the substrate 10 may be a transparent glass substrate or a flexible plastic substrate when manufacturing an organic light emitting device.

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

For the hole injection layer 200, the hole transport layer 300, the light emitting layer 400, and the electron transport layer 500, materials listed in Table 2 below were used.

A cathode 2000 for electron injection was formed on the electron injection layer 600. Various metals can be used as the cathode. Specific examples include materials such as aluminum, gold, and silver.

Example 11: Preparation of an organic light emitting device according to the present invention

On the ITO substrate on which the reflective layer containing Ag was formed, a hole injection layer HI01 600Å, HATCN 50Å, and a BPA 500Å were formed as a hole transport layer, and then doped with BH01:BD01 3% as the light emitting layer to form 250Å. Next, an ET01:Liq(1:1) 300 으로 film was formed as an electron transport layer, and then LiF 10 증착 was deposited to form an electron injection layer. Subsequently, MgAg was deposited to a thickness of 15 nm, and the compound prepared in Example 1 was deposited to a thickness of 850 mm 2 as a capping layer on the cathode. An organic light emitting device was manufactured by encapsulating the device in a glove box.

Examples 12 to 20: Preparation of organic light emitting device according to the present invention

In the same manner as in Example 11, using the compounds prepared in Examples 2 to 10, respectively, an organic light-emitting device formed into a capping layer was produced.

Comparative Examples 1 to 5: Preparation of organic light emitting device

In the same manner as in Example 11, using the Ref. 1 to Ref. 5 shown in Table 2, an organic light emitting device formed into a capping layer was manufactured.

Experimental Example 1: Evaluation of the performance of the organic light emitting device

A voltage is applied to a Keithley 2400 source measurement unit to inject electrons and holes, and a luminance is measured when light is emitted using a Konica Minolta spectroradiometer (CS-2000). By doing so, the performances of the organic light emitting devices of Examples 11 to 20 and Comparative Examples 1 to 5 were evaluated by measuring the current density and luminance for the applied voltage under atmospheric pressure conditions, and the results are shown in Table 3 below.

Op. V mA/cm2 Cd/A QE (%) CIEx CIEy LT97 Example 1 3.94 10 8.68 7.61 0.137 0.051 150 Example 2 3.95 10 8.72 7.64 0.137 0.050 152 Example 3 3.94 10 8.83 7.70 0.137 0.049 165 Example 4 3.94 10 8.96 7.83 0.137 0.048 175 Example 5 3.95 10 8.95 7.88 0.137 0.048 177 Example 6 3.95 10 8.97 7.80 0.138 0.048 175 Example 7 3.95 10 8.95 7.85 0.138 0.048 173 Example 8 3.95 10 9.17 8.04 0.138 0.049 185 Example 9 3.95 10 9.15 8.00 0.138 0.049 187 Example 10 3.95 10 8.67 7.68 0.138 0.050 155 Comparative Example 1 3.95 10 6.48 5.29 0.133 0.064 80 Comparative Example 2 3.96 10 7.25 6.12 0.133 0.056 82 Comparative Example 3 3.95 10 6.70 5.54 0.131 0.060 89 Comparative Example 4 3.96 10 7.02 6.00 0.132 0.060 99 Comparative Example 5 3.96 10 7.48 6.35 0.134 0.055 108

In Examples 11 to 20 of the present invention, in comparison to Comparative Examples 1 to 3, dibenzofuran or dibenzothiophene is bound to one side of amine and dibenzofuran, dibenzothiophene or fluorene to the other side. By combining, it is possible to obtain a wide band gap that cannot absorb the visible region, and at the same time, dibenzofuran, dibenzothiophene or fluorene are all bonded to the amine through an arylene linkage group to maintain a high refractive index, improving color purity and efficiency It is effective. In addition, as compared to Comparative Examples 4 and 5, by including an aryl group or a heteroaryl group having 10 or more carbon atoms in Ar ₁ bound to an amine, not only the refractive index is increased, but also the absorption wavelength in the ultraviolet region is increased, so it can be stable from external ultraviolet exposure Therefore, the efficiency is further improved and it can have a long life. In addition, including a substituent with a small bulky property such as dibenzofuran, dibenzothiophene or fluorene, it is possible to form an amorphous thin film with an excellent thin film arrangement of molecules upon deposition, thereby improving life through blocking of external air and moisture. At the same time, it can be seen that with high Tg and high Td, it is possible to prevent recrystallization between molecules and to maintain a stable thin film from heat generated during driving, and further improve the life.

Experimental Example 2: Evaluation of refractive index

Using a compound 478, 480 and 517 and Ref. 1 compound, a 30 nm thick deposited film was fabricated on a silicon substrate using vacuum deposition equipment, and an ellipsometer device (JAWoollam Co. Inc, M-2000X) was used. The refractive index of 450 nm was measured. The results are summarized in Table 4 below.

@450nm Ref.1 Compound 478 Compound 480 Compound 517 Refractive index, n 2.010 2.312 2.320 2.425

As described in Table 4 above, it can be confirmed that the compounds 478, 480, and 517 have a high refractive index of 2.1 or more, more specifically 2.2 or more.

Experimental Example 3: Evaluation of absorption intensity in the ultraviolet region

Using a compound 480 and Ref. 1 compound in the ultraviolet region, a 30 nm thick deposited film on a silicon substrate was fabricated using vacuum deposition equipment, and an ellipsometer device (JAWoollam Co. Inc, M-2000X) was used. The absorption wavelength in the range of 250 nm to 1,000 nm was measured. The results are as shown in FIG. 2.

Based on the ultraviolet absorption region of 380 nm, the absorption strength of the compound 480 is 0.6 or more, specifically 0.7 or more, and it can be seen that the absorption strength is increased by 10% or more, more specifically 20% or more, than the Ref.1 compound.

The foregoing description of the present application is for illustration, and a person having ordinary knowledge in the technical field to which the present application belongs will understand that it is possible to easily change to other specific forms without changing the technical spirit or essential characteristics 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 distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present application is indicated by the claims to be described later rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted to be included in the scope of the present application. .

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

Claims (16)

Compound for a capping layer represented by the following formula (1):
[Formula 1]

In Chemical Formula 1,
X is O or S,
Y is O, S or CR`R,
R`, R``, R <sub>1</sub> to R <sub>4</sub> are each independently hydrogen, deuterium, a halogen, a nitro group, a nitrile group, a substituted or unsubstituted C <sub>1 ~ 30</sub> alkyl group, a substituted or unsubstituted C <sub>2 ~ 30</sub> alkenyl group , substituted or unsubstituted C <sub>1 ~ 30</sub> alkoxy group, a substituted or unsubstituted C <sub>1 ~ 30</sub> sulfide group, a substituted or unsubstituted C <sub>6 ~ 50</sub> aryl group, or a substituted or unsubstituted C <sub>2 ~ 50</sub> hetero aryl group, And (where R` and R`` may combine with each other to form a ring or not),
l and o are each independently 0 or an integer from 1 to 4,
m and n are each independently 0 or an integer from 1 to 3,
L ₁ and L ₂ are each independently a substituted or unsubstituted C _{6 ~ 50} aryl group, or a substituted or unsubstituted C _{2 ~ 50} hetero arylene group,
Ar ₁ is either one of a substituted or unsubstituted C _{6 ~ 50} aryl group, a substituted or unsubstituted C _{2 ~ 50} hetero arylene group, or combinations thereof (however, L ₁ and L ₂ is at least C _16, L _{When 1} and L ₂ are both C ₁₀ or more aryl groups, Ar ₁ may be a phenyl group).
According to claim 1,
Formula 1 is a compound for a capping layer represented by the following formula (2):
[Formula 2]

In Chemical Formula 2,
X, Y, R`, R``, R ₁ to R ₄ , l, m, n, o and Ar ₁ are as defined in claim 1,
R ₅ and R ₆ are each independently a hydrogen, a deuterium, a halogen, a nitro group, a nitrile group, a substituted or unsubstituted C _{1 ~ 30} alkyl group, a substituted or unsubstituted C _{2 ~ 30} alkenyl group, a substituted or unsubstituted C _{1 to 30} and an alkoxy group, a substituted or unsubstituted C _1-30 sulfide group, a substituted or unsubstituted C _{6 ~ 50} aryl group, or a substituted or unsubstituted C _{2 ~ 50} hetero aryl group,
p and q are each independently an integer of 1-4.
According to claim 1,
Chemical Formula 1 is a compound for a capping layer represented by Chemical Formula 3 below:
[Formula 3]

In Chemical Formula 3,
X, Y, R`, R``, R ₁ to R ₄ , l, m, n, o and Ar ₁ are as defined in claim 1,
p and q are each independently an integer of 1-4.
According to claim 1,
Chemical Formula 1 is a compound for a capping layer represented by Chemical Formula 4 below:
[Formula 4]

In Chemical Formula 4,
X, Y, R`, R``, R ₁ to R ₄ , l, o and Ar ₁ are as defined in claim 1,
m and n are each independently 0, 1 or 2,
p and q are each independently an integer of 1-4.
According to claim 1,
Chemical Formula 1 is a compound for a capping layer represented by Chemical Formula 5 below:
[Formula 5]

In Chemical Formula 5,
X, Y, R`, R``, R ₁ to R ₄ , l and o are as defined in claim 1,
m and n are each independently 0, 1 or 2,
p and q are each independently an integer from 1 to 4,
Ar ₂ is a substituted or unsubstituted C _{6 to 44} arylene group, a substituted or unsubstituted C _{2 to 44} heteroarylene group, or a combination thereof.
According to claim 1,
Chemical Formula 1 is a compound for a capping layer represented by Chemical Formula 6 below:
[Formula 6]

In Chemical Formula 6,
X, Y, R`, R``, R <sub>1</sub> to R <sub>4</sub> , l and o are as defined in claim 1,
m and n are each independently 0, 1 or 2,
p and q are each independently an integer of 1 to 4, and the sum of p and q is an integer of 4 or more.
The method according to any one of claims 2 to 6,
At least one of p and q is an integer of 2 or 3.
According to claim 1,
Wherein X and Y are each independently O or S capping layer compound.
According to claim 1,
R <sub>1</sub> to R <sub>4</sub> are each independently hydrogen, methyl, fluoro, methoxy, cyano, phenyl or biphenyl compound for a capping layer.
According to claim 1,
The R` and R`` are each independently a compound for a capping layer which is hydrogen or methyl.
According to claim 1,
The Ar ₁ is a naphthyl, biphenyl, terphenyl, phenanthrenyl, triphenylenyl, dibenzofuranyl, dibenzothiophenyl, pyridinyl, or a combination thereof, a compound for a capping layer.
The method of claim 5,
The Ar ₂ is a compound for a capping layer which is phenyl, naphthyl, biphenyl, terphenyl, phenanthrenyl, triphenylenyl, dibenzofuranyl, dibenzothiophenyl, pyridinyl or a combination thereof.
The method of claim 5,
The Ar ₂ is a compound for a capping layer comprising dibenzofuranyl or dibenzothiophenyl.
According to claim 1,
Formula 1 is a compound for a capping layer of any one of the following compounds:

.
A first electrode and a second electrode;
An organic material layer interposed inside the first electrode and the second electrode; And
A capping layer disposed outside one or more of the first electrode and the second electrode, and containing the compound for a capping layer according to any one of claims 1 to 14; Organic light emitting device comprising a.
The method of claim 15,
The thickness of the capping layer is an organic light emitting device of 300 to 1,000 Å.

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