KR102261704B1 - Tertiary amine derivatives and organic electroluminescent device including the same - Google Patents

Abstract

Provided is a tertiary amine derivative, which effectively absorbs high-energy external light sources in the UV region to minimize damage to organic materials inside an organic electroluminescent (EL) device, thereby contributing to a practical improvement of the lifespan of the organic EL device. An organic EL device according to the present invention comprises: a first electrode; a second electrode; one or more organic material layers disposed between the first electrode and the second electrode; and a capping layer, wherein the capping layer includes a tertiary amine derivative represented by formula 1 below: [Formula 1], in which each of substituents are the same as defined in the detailed descriptions of the invention.

Description

Tertiary amine derivatives and organic electroluminescent device including the same

The present invention relates to a tertiary amine derivative and an organic electroluminescent device including the same, and to have an organic electroluminescent device including a capping layer by the tertiary amine derivative simultaneously have refractive properties and ultraviolet absorption properties.

OLED (Organic Light Emitting Diodes) is attracting attention as a display using the self-luminescence phenomenon in the display industry.

In OLED, a study of carrier injection electroluminescence (EL) using a single crystal of an anthracene aromatic hydrocarbon was first attempted by Pope et al. in 1963. From these studies, basic mechanisms such as charge injection, recombination, exciton generation, and light emission in organic materials and electroluminescence properties have been understood and studied.

In particular, in order to increase the luminous efficiency, various approaches such as structural changes and material development of devices are being made [Sun, S., Forrest, S. R., Appl. Phys. Lett. 91, 263503 (2007)/Ken-Tsung Wong, Org. Lett., 7, 2005, 5361-5364].

The basic structure of an OLED display is generally an anode, a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), and an electron transport layer (ETL). ), and a multilayer structure of a cathode, and a sandwich structure in which an electron organic multilayer film is formed between two electrodes.

In general, the organic light emitting phenomenon refers to a phenomenon in which electric energy is converted into light energy using an organic material. An organic light emitting device using an organic light emitting phenomenon typically has a structure including an anode and a cathode and an organic material layer therebetween. Here, the organic material layer is often formed of a multilayer structure made of different materials in order to increase the efficiency and stability of the organic light emitting device, and may include, for example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like. When a voltage is applied between the two electrodes in the structure of the organic light emitting device, holes are injected into the organic material layer from the anode and electrons from the cathode are injected into the organic material layer. When the injected holes and electrons meet, excitons are formed, and the excitons are formed at the bottom. It lights up when it falls into a state. Such an organic light emitting device is known to have characteristics such as self-luminescence, high luminance, high efficiency, low driving voltage, wide viewing angle, high contrast, and high-speed response.

A material used as an organic material layer in an organic light emitting device may be classified into a light emitting material and a charge transporting material such as a hole injecting material, a hole transporting material, an electron transporting material, an electron injecting material, and the like according to functions.

The light-emitting material includes blue, green, and red light-emitting materials depending on the light-emitting color, and yellow and orange light-emitting materials required to realize better natural colors. In addition, in order to increase color purity and increase luminous efficiency through energy transfer, a host/dopant system may be used as a light emitting material. The principle is that when a small amount of a dopant having a smaller energy band gap and superior luminous efficiency than the host constituting the light emitting layer is mixed in a small amount in the light emitting layer, excitons generated from the host are transported to the dopant to emit light with high efficiency. At this time, since the wavelength of the host moves to the wavelength band of the dopant, light having a desired wavelength can be obtained according to the type of dopant used.

In order to sufficiently express the excellent characteristics of the above-described organic light emitting device, materials constituting the organic material layer in the device, such as a hole injection material, a hole transport material, a light emitting material, an electron transport material, an electron injection material, etc. The performance of the organic light emitting device is recognized by the products.

However, as the commercialization of the organic light emitting device is made and time passes, the need for other characteristics in addition to the light emitting characteristic of the organic light emitting device itself is emerging.

Since the organic light emitting diode is exposed to an external light source for a large amount of time, it is in an environment exposed to ultraviolet rays having high energy. Accordingly, there is a problem in that the organic material constituting the organic light emitting device is continuously affected. In order to prevent exposure to such a high energy light source, the problem can be solved by applying a capping layer having ultraviolet absorption characteristics to the organic light emitting diode.

In general, it is known that the viewing angle characteristics of an organic light emitting device are wide, but from the viewpoint of the light source spectrum, a significant deviation occurs depending on the viewing angle. This is due to the total refractive index of the glass substrate, organic material, electrode material, etc. and the emission wavelength of the organic light emitting device. This is due to the occurrence of a deviation between the appropriate refractive indices.

In general, the larger the required refractive index value of blue and the longer the wavelength, the smaller the required refractive index value. Accordingly, it is necessary to develop a material for forming a capping layer that simultaneously satisfies the above-mentioned ultraviolet absorption characteristics and an appropriate refractive index.

The efficiency of the organic light emitting diode can be generally divided into internal luminescent efficiency and external luminescent efficiency. The internal luminous efficiency is related to the efficiency of the formation of excitons in the organic layer for light conversion to take place.

The external luminous efficiency refers to the efficiency at which light generated in the organic layer is emitted to the outside of the organic light emitting device.

In order to improve the overall efficiency, not only the internal luminous efficiency but also the external luminous efficiency and efficiency should be increased. There is a demand for the development of a capping layer (CPL) material having an excellent ability to increase external luminous efficiency.

Republic of Korea Patent Publication No. 2016-0062307 (Title of the invention: organic light emitting display device including a high refractive index capping layer)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a capping layer material for an organic light emitting device, which can improve luminous efficiency and lifespan and can improve viewing angle characteristics.

It is an object of the present invention to provide an organic electroluminescent device with high efficiency and long life, including a capping layer having improved refractive index and heat resistance, in particular, in order to improve the light extraction rate of the organic electroluminescent device.

The present invention is a first electrode; an organic material layer disposed on the first electrode; a second electrode disposed on the organic material layer; and a capping layer disposed on the second electrode, wherein the organic material layer or the capping layer provides an organic electroluminescent device including a tertiary amine derivative represented by the following Chemical Formula 1.

[Formula 1]

In Formula 1,

Ar ₁ and Ar ₂ are each independently an unsubstituted aryl group having 6 or more and 20 or less carbon atoms,

X ₁ , X ₂ and X ₃ are each independently CH or N (at least two or more must be N),

Ar ₃ and Ar ₄ are each independently F, CF ₃ , and Si(CH ₃ ) ₃ It is an aryl group or heteroaryl group having 6 or more and 20 or less carbon atoms, substituted with at least one of them.

The compound described herein may be used as a material for an organic material layer of an organic light emitting device.

The compound according to the present invention exhibits ultraviolet absorption characteristics, thereby minimizing damage to organic materials in the organic light emitting device caused by an external light source, and improving efficiency, low driving voltage and/or lifespan characteristics in the organic light emitting device.

In addition, in an organic light emitting device using the compound described in the present specification as a capping layer, it is possible to significantly improve luminous efficiency and color purity according to a decrease in the emission spectrum half width.

1 illustrates a first electrode 110, a hole injection layer 210, a hole transport layer 215, a light emitting layer 220, an electron transport layer 230, and an electron injection layer on a substrate 100 according to an embodiment of the present invention. An example of an organic light emitting device in which 235 , the second electrode 120 , and the capping layer 300 are sequentially stacked is shown.
2 is a graph of the refraction and absorption characteristics of light appearing when using a tertiary amine derivative according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail.

Since the present invention can have various changes and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

In describing each figure, like reference numerals have been used for like elements. In the accompanying drawings, the dimensions of the structures are enlarged than the actual dimensions for clarity of the present invention. Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. The singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It is to be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof. Also, when a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case where it is "directly on" another part, but also the case where there is another part in between.

As used herein, "substituted or unsubstituted" is a deuterium atom, a halogen atom, a cyano group, a nitro group, an amino group, a hydroxy group, a silyl group, a boron group, a phosphine oxide group, a phosphine sulfide group, an alkyl group, an alkoxy group, an alke group It may mean unsubstituted or substituted with one or more substituents selected from the group consisting of a nyl group, an aryl group, a heteroaryl group, and a heterocyclic group. In addition, each of the substituents exemplified above may be substituted or unsubstituted. For example, a biphenyl group may be interpreted as an aryl group or a phenyl group substituted with a phenyl group.

In the present specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

In the present specification, the alkyl group may be linear, branched or cyclic. Carbon number of an alkyl group is 1 or more and 50 or less, 1 or more and 30 or less, 1 or more and 20 or less, 1 or more and 10 or less, or 1 or more and 6 or less. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, s-butyl group, t-butyl group, i-butyl group, 2-ethylbutyl group, 3, 3-dimethylbutyl group , n-pentyl group, i-pentyl group, neopentyl group, t-pentyl group, cyclopentyl group, 1-methylpentyl group, 3-methylpentyl group, 2-ethylpentyl group, 4-methyl-2-pentyl group , n-hexyl group, 1-methylhexyl group, 2-ethylhexyl group, 2-butylhexyl group, cyclohexyl group, 4-methylcyclohexyl group, 4-t-butylcyclohexyl group, n-heptyl group, 1 -Methylheptyl group, 2,2-dimethylheptyl group, 2-ethylheptyl group, 2-butylheptyl group, n-octyl group, t-octyl group, 2-ethyloctyl group, 2-butyloctyl group, 2-hexyl group Siloctyl group, 3,7-dimethyloctyl group, cyclooctyl group, n-nonyl group, n-decyl group, adamantyl group, 2-ethyldecyl group, 2-butyldecyl group, 2-hexyldecyl group, 2-ox Tyldecyl group, n-undecyl group, n-dodecyl group, 2-ethyldodecyl group, 2-butyldodecyl group, 2-hexyldodecyl group, 2-octyldodecyl group, n-tridecyl group, n-tetradecyl group, n -Pentadecyl group, n-hexadecyl group, 2-ethylhexadecyl group, 2-butylhexadecyl group, 2-hexylhexadecyl group, 2-octylhexadecyl group, n-heptadecyl group, n-octadecyl group , n-nonadecyl group, n-icosyl group, 2-ethyl icosyl group, 2-butyl icosyl group, 2-hexyl icosyl group, 2-octyl icosyl group, n-henicosyl group, n-docosyl group, n-tricho Sil group, n-tetracosyl group, n-pentacosyl group, n-hexacosyl group, n-heptacosyl group, n-octacosyl group, n-nonacosyl group, and n-triacontyl group etc. are mentioned, It is not limited to these.

As used herein, the hydrocarbon ring group means any functional group or substituent derived from an aliphatic hydrocarbon ring. The hydrocarbon ring group may be a saturated hydrocarbon ring group having 5 to 20 ring carbon atoms.

As used herein, the aryl group means any functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group may be a monocyclic aryl group or a polycyclic aryl group. The number of ring carbon atoms of the aryl group may be 6 or more and 30 or less, 6 or more and 20 or less, or 6 or more and 15 or less. Examples of the aryl group include a phenyl group, a naphthyl group, a fluorenyl group, an anthracenyl group, a phenanthryl group, a biphenyl group, a terphenyl group, a quarterphenyl group, a quinkphenyl group, a sexyphenyl group, a triphenylenyl group, a pyrenyl group, a peryleneyl group, a naphtha group Although a cenyl group, a pyrenyl group, a benzo fluoranthenyl group, a chrysenyl group, etc. can be illustrated, it is not limited to these.

In the present specification, the heteroaryl group may be a heteroaryl group including at least one of O, N, P, Si and S as a heterogeneous element. The N and S atoms may optionally be oxidized and the N atom(s) may optionally be quaternized. The number of ring carbon atoms in the heteroaryl group is 2 or more and 30 or less, or 2 or more and 20 or less. The heteroaryl group may be a monocyclic heteroaryl group or a polycyclic heteroaryl group. The polycyclic heteroaryl group may have, for example, a bicyclic or tricyclic structure.

Examples of the heteroaryl group include a thiophene group, a furan group, a pyrrole group, an imidazole group, a pyrazolyl group, a thiazole group, an oxazole group, an oxadiazole group, a triazole group, a pyridine group, a bipyridine group, a pyrimidine group, a triazine group , tetrazine group, triazole group, tetrazole group, acridyl group, pyridazine group, pyrazinyl group, quinoline group, quinazoline group, quinoxaline group, phenoxazine group, phthalazine group, pyridopyrimidine group, pyridopyrazino group Pyrazine group, isoquinoline group, cinnol group, indole group, isoindole group, indazole group, carbazole group, N-arylcarbazole group, N-heteroarylcarbazole group, N-alkylcarbazole group, benzoxazole group, benzoimidazole group , benzothiazole group, benzocarbazole group, benzothiophene group, benzothiophene group, benzoisothiazolyl, benzoisoxazolyl, dibenzothiophene group, thienothiophene group, benzofuran group, phenanthroline group, phenanthridine group , a thiazole group, an isoxazole group, an oxadiazole group, a thiadiazole group, an isothiazole group, an isoxazole group, a phenothiazine group, a benzodioxol group, a dibenzosilol group and a dibenzofuran group, an isobenzofuran group, etc. It is not limited to these. In addition, there are N-oxide aryl groups corresponding to the monocyclic heteroaryl group or polycyclic heteroaryl group, for example, quaternary salts such as pyridyl N-oxide group and quinolyl N-oxide group, but these include not limited

In the present specification, the silyl group includes an alkyl silyl group and an aryl silyl group. Examples of the silyl group include a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, a propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, a phenylsilyl group, and the like. not limited

In the present specification, examples of the arylamine group include a substituted or unsubstituted monoarylamine group, a substituted or unsubstituted diarylamine group, or a substituted or unsubstituted triarylamine group. The aryl group in the arylamine group may be a monocyclic aryl group, and may include a polycyclic aryl group, or a monocyclic aryl group and a polycyclic aryl group at the same time.

Specific examples of the arylamine group include a phenylamine group, a naphthylamine group, a biphenylamine group, an anthracenylamine group, a 3-methyl-phenylamine group, a 4-methyl-naphthylamine group, and a 2-methyl-biphenylamine group. group, 9-methyl-anthracenylamine group, diphenyl amine group, phenyl naphthylamine group, ditolyl amine group, phenyl tolyl amine group, carbazole and triphenyl amine group, but is not limited thereto.

In the present specification, examples of the heteroallylamine group include a substituted or unsubstituted monoheteroarylamine group, a substituted or unsubstituted diheteroarylamine group, or a substituted or unsubstituted triheteroarylamine group. The heteroaryl group in the heteroarylamine group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group. The heteroarylamine group including two or more heterocyclic groups may include a monocyclic heterocyclic group, a polycyclic heterocyclic group, or a monocyclic heterocyclic group and a polycyclic heterocyclic group at the same time.

In the present specification, the aryl heteroarylamine group refers to an amine group substituted with an aryl group and a heterocyclic group.

As used herein, the term “adjacent group” may mean a substituent substituted on an atom directly connected to the atom in which the substituent is substituted, another substituent substituted on the atom in which the substituent is substituted, or a substituent most sterically adjacent to the substituent. have. For example, two methyl groups in 1,2-dimethylbenzene can be interpreted as “adjacent groups” to each other, and 2 in 1,1-diethylcyclopentene The two ethyl groups can be interpreted as “adjacent groups” to each other.

Hereinafter, the tertiary amine derivative compound used in the organic material layer and/or the capping layer will be described.

The tertiary amine derivative compound according to an embodiment of the present invention is represented by the following formula (1).

[Formula 1]

In Formula 1,

Ar ₁ and Ar ₂ are each independently an unsubstituted aryl group having 6 or more and 20 or less carbon atoms,

X ₁ , X ₂ and X ₃ are each independently CH or N (at least two or more must be N),

Ar ₃ and Ar ₄ are each independently F, CF ₃ , and Si(CH ₃ ) ₃ It is an aryl group or heteroaryl group having 6 or more and 20 or less carbon atoms, substituted with at least one of them.

The compound represented by Formula 1 is a tertiary amine derivative for an organic electroluminescent device represented by Formula 2 below.

[Formula 2]

In Formula 2,

Ar ₁ and Ar ₂ are each independently an unsubstituted aryl group having 6 or more and 12 or less carbon atoms,

X ₁ , X ₂ and X ₃ are each independently CH or N (at least two or more must be N),

R ₁ and R ₂ are each independently at least one selected from _{F, CF 3} and Si(CH ₃ ) _{3 ,}

n ₁ and n ₂ are each independently an integer of 1 or more and 5 or less.

In an embodiment of the present invention, the tertiary amine derivative represented by Chemical Formulas 1 and/or 2 may be any one selected from compounds represented by Chemical Formulas 3 and 4, and the following compounds may be further substituted. have.

[Formula 3]

[Formula 4]

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2 .

1 is a cross-sectional view schematically illustrating an organic light emitting diode according to an embodiment of the present invention. Referring to FIG. 1 , in an organic light emitting device according to an embodiment, a first electrode 110 , a hole injection layer 210 , a hole transport layer 215 , a light emitting layer 220 , and electrons are sequentially stacked on a substrate 100 . It may include a transport layer 230 , an electron injection layer 235 , a second electrode 120 , and a capping layer 300 .

The first electrode 110 and the second electrode 120 are disposed to face each other, and the organic material layer 200 may be disposed between the first electrode 110 and the second electrode 120 . The organic material layer 200 may include a hole injection layer 210 , a hole transport layer 215 , a light emitting layer 220 , an electron transport layer 230 , and an electron injection layer 235 .

Meanwhile, the capping layer 300 presented in the present invention is a functional layer deposited on the second electrode 120 and includes an organic material according to Chemical Formula 1 of the present invention.

In the organic light emitting diode according to the exemplary embodiment shown in FIG. 1 , the first electrode 110 has conductivity. The first electrode 110 may be formed of a metal alloy or a conductive compound. The first electrode 110 is generally an anode, but the function as an electrode is not limited.

The first electrode 110 may be formed by depositing an electrode material on the substrate 100 using a deposition method, electron beam evaporation, or sputtering. The material of the first electrode 110 may be selected from materials having a high work function to facilitate injection of holes into the organic light emitting device.

The capping layer 300 proposed in the present invention is applied when the emission direction of the organic light emitting device is top emission, and therefore, the first electrode 110 uses a reflective electrode. These materials include Mg (magnesium), Al (aluminum), Al-Li (aluminum-lithium), Ca (calcium), Mg-In (magnesium-indium), Mg-Ag (magnesium-silver) and It can also be manufactured using the same metal. In recent years, carbon substrate flexible electrode materials such as CNT (carbon nanotube) and graphene (graphene) may be used.

The organic material layer 200 may be formed of a plurality of layers. When the organic material layer 200 is a plurality of layers, the organic material layer 200 includes the hole transport regions 210 to 215 disposed on the first electrode 110 , the light emitting layer 220 disposed on the hole transport region, and the light emitting layer. It may include electron transport regions 230 to 235 disposed on 220 .

The capping layer 300 of an embodiment includes an organic compound represented by Chemical Formula 1 to be described later.

The hole transport regions 210 to 215 are provided on the first electrode 110 . The hole transport regions 210 to 215 may include at least one of a hole injection layer 210, a hole transport layer 215, a hole buffer layer, and an electron blocking layer (EBL). In general, since hole mobility is faster than electron mobility, it has a thicker thickness than the electron transport region.

The hole transport regions 210 to 215 may have a single layer made of a single material, a single layer made of a plurality of different materials, or a multilayer structure having a plurality of layers made of a plurality of different materials.

For example, the hole transport regions 210 to 215 may have a single-layer structure of the hole injection layer 210 or the hole transport layer 215 , or may have a single-layer structure including a hole injection material and a hole transport material. have. In addition, the hole transport regions 210 to 215 have a single layer structure made of a plurality of different materials, or a hole injection layer 210/hole transport layer 215 stacked sequentially from the first electrode 110 , Hole injection layer 210 / hole transport layer 215 / hole buffer layer, hole injection layer 210 / hole buffer layer, hole transport layer 215 / hole buffer layer, or hole injection layer 210 / hole transport layer 215 / electron It may have a structure of the blocking layer EBL, but the embodiment is not limited thereto.

The hole injection layer 210 of the hole transport regions 210 to 215 may be formed on the anode by various methods, such as a vacuum deposition method, a spin coating method, a casting method, and an LB method. When the hole injection layer 210 is formed by vacuum deposition, the deposition conditions are 100 to 500 depending on the compound used as the material for the hole injection layer 210, the structure and thermal characteristics of the hole injection layer 210, etc. The deposition rate at ℃ can be freely controlled by adjusting the deposition rate before and after 1 Å/s, and is not limited to specific conditions. In the case of forming the hole injection layer 210 by the spin coating method, the coating conditions are different depending on the characteristics between the compound used as the hole injection layer 210 material and the layers formed as the interface, but for an even film formation, the coating speed, coating After that, heat treatment to remove the solvent is required.

The hole transport regions 210 to 215 are, for example, m-MTDATA, TDATA, 2-TNATA, NPB, β-NPB, TPD, Spiro-TPD, Spiro-NPB, methylated-NPB, TAPC, HMTPD, TCTA. (4,4',4"-tris(N-carbazolyl)triphenylamine (4,4',4"-tris(Ncarbazolyl)triphenylamine)), Pani/DBSA (Polyaniline/Dodecylbenzenesulfonic acid: polyaniline/dodecylbenzene sulfonic acid), PEDOT/PSS (Poly(3,4-ethylenedioxythiophene) /Poly(4-styrene sulfonate):poly(3,4-ethylenedioxythiophene) /poly(4-styrenesulfonate)), Pani/CSA ( Polyaniline/Camphor sulfonicacid: polyaniline/camphorsulfonic acid), PANI/PSS (Polyaniline)/Poly(4-styrenesulfonate):polyaniline)/poly(4-styrenesulfonate)), and the like.

The hole transport regions 210 to 215 may have a thickness of about 100 to about 10,000 Å, and the organic material layers of each of the hole transport regions 210 to 215 are not limited to the same thickness. For example, if the hole injection layer 210 has a thickness of 50 Å, the hole transport layer 215 may have a thickness of 1000 Å and the electron blocking layer may have a thickness of 500 Å. The thickness condition of the hole transport regions 210 to 215 may be determined to a degree that satisfies the efficiency and lifespan within a range in which the increase in the driving voltage of the organic light emitting device does not increase. The organic layer 200 includes a hole injection layer 210 , a hole transport layer 215 , a functional layer having a hole injection function and a hole transport function at the same time, a buffer layer, an electron blocking layer, a light emitting layer 220 , a hole blocking layer, an electron transport layer 230 , the electron injection layer 235 , and one or more layers selected from the group consisting of a functional layer having an electron transport function and an electron injection function at the same time.

The hole transport regions 210 to 215 may use doping to improve properties like the light emitting layer 220 , and doping of a charge-generating material into the hole transport regions 210 to 215 may improve the electrical properties of the organic light emitting device. can

The charge-generating material is generally made of a material having a very low HOMO and LUMO. For example, the LUMO of the charge-generating material has a value similar to the HOMO of the hole transport layer 215 material. Due to the low LUMO, holes are easily transferred to the adjacent hole transport layer 215 by using the electron vacancy characteristic of the LUMO, thereby improving electrical properties.

The charge-generating material may be, for example, a p-dopant. The p-dopant may be one of a quinone derivative, a metal oxide, and a cyano group-containing compound, but is not limited thereto. For example, non-limiting examples of the p-dopant include tetracyanoquinonedimethane (TCNQ) and 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane quinone derivatives such as phosphorus (F4-TCNQ) and the like; metal oxides such as tungsten oxide and molybdenum oxide; and a cyano group-containing compound such as Compound 2-22 below, but is not limited thereto.

In addition to the aforementioned materials, the hole transport regions 210 to 215 may further include a charge generating material to improve conductivity. The charge generating material may be uniformly or non-uniformly dispersed in the hole transport regions 210 to 215 . The charge generating material may be, for example, a p-dopant. The p-dopant may be one of a quinone derivative, a metal oxide, and a cyano group-containing compound, but is not limited thereto. For example, non-limiting examples of p-dopants include quinone derivatives such as TCNQ (Tetracyanoquinodimethane) and F4-TCNQ (2,3,5,6-tetrafluoro-tetracyanoquinodimethane), and metal oxides such as tungsten oxide and molybdenum oxide. may be mentioned, but is not limited thereto.

As described above, the hole transport regions 210 to 215 may further include at least one of a hole buffer layer and an electron blocking layer in addition to the hole injection layer 210 and the hole transport layer 215 . The hole buffer layer may increase light emission efficiency by compensating for a resonance distance according to a wavelength of light emitted from the emission layer 220 . As a material included in the hole buffer layer, a material that may be included in the hole transport regions 210 to 215 may be used.

The electron blocking layer is a layer serving to prevent electron injection from the electron transport region 230 to 235 to the hole transport region 210 to 215 . The electron blocking layer may use a material having a high T1 value so that excitons formed in the emission layer 220 do not diffuse into the hole transport regions 210 to 215 as well as to block electrons moving to the hole transport region. For example, a host of the light emitting layer 220 having a generally high T _{1 value may be used as the electron blocking layer material.}

The emission layer 220 is provided on the hole transport regions 210 to 215 . The light emitting layer 220 may have a thickness of, for example, about 100 Å to about 1000 Å, or about 100 Å to about 300 Å. The emission layer 220 may have a single layer made of a single material, a single layer made of a plurality of different materials, or a multilayer structure having a plurality of layers made of a plurality of different materials.

The light emitting layer 220 is a region where holes and electrons meet to form excitons. The material constituting the light emitting layer 220 must have an appropriate energy band gap to exhibit high light emitting characteristics and a desired light emitting color, and generally serve as a host and a dopant. It consists of two materials, but is not limited thereto.

The host may include at least one of the following TPBi, TBADN, ADN (also referred to as “DNA”), CBP, CDBP, TCP, and mCP, and if the properties are appropriate, the material is not limited thereto.

The dopant of the light emitting layer 220 according to an embodiment may be an organometallic complex. The general dopant content may be selected from 0.01 to 20%, but in some cases, it is not limited thereto.

The electron transport regions 230 to 235 are provided on the emission layer 220 . The electron transport regions 230 to 235 may include at least one of a hole blocking layer, an electron transport layer 230 , and an electron injection layer 235 , but are not limited thereto.

The electron transport regions 230 to 235 may have a single layer made of a single material, a single layer made of a plurality of different materials, or a multilayer structure having a plurality of layers made of a plurality of different materials.

For example, the electron transport regions 230 to 235 may have a single-layer structure of the electron injection layer 235 or the electron transport layer 230 , or may have a single-layer structure including an electron injection material and an electron transport material. have. In addition, the electron transport regions 230 to 235 have a single layer structure made of a plurality of different materials, or the electron transport layer 230/electron injection layer 235 and the hole blocking layer that are sequentially stacked from the light emitting layer 220 . It may have a layer/electron transport layer 230/electron injection layer 235 structure, but is not limited thereto. The thickness of the electron transport regions 230 to 235 may be, for example, about 1000 Å to about 1500 Å.

The electron transport regions 230 to 235 may be formed by various methods such as a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, and a laser induced thermal imaging (LITI) method. method can be used.

When the electron transport regions 230 to 235 include the electron transport layer 230 , the electron transport region 230 may include an anthracene-based compound. However, the present invention is not limited thereto, and the electron transport region is, for example, Alq3(Tris(8-hydroxyquinolinato)aluminum),1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene,2 ,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine,2-(4-(N-phenylbenzoimidazolyl-1-ylphenyl)-9,10 -dinaphthylanthracene,TPBi(1,3,5-Tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl),BCP(2,9-Dimethyl-4,7-diphenyl-1,10- phenanthroline), Bphen(4,7-Diphenyl-1,10-phenanthroline),TAZ(3-(4-Biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole),NTAZ(4 -(Naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole),tBu-PBD(2-(4-Biphenylyl)-5-(4-tert-butylphenyl)-1, 3,4-oxadiazole), BAlq(Bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-Biphenyl-4-olato)aluminum), Bebq2(berylliumbis(benzoquinolin-10-olate), ADN (9,10-di(naphthalene-2-yl)anthracene) and mixtures thereof may be included.

Since the electron transport layer 230 is selected as a material having a fast electron mobility or a slow electron mobility according to the structure of the organic light emitting device, various materials need to be selected, and in some cases, Liq or Li may be doped.

The thickness of the electron transport layers 230 may be about 100 Å to about 1000 Å, for example, about 150 Å to about 500 Å. When the thickness of the electron transport layers 230 satisfies the above-described range, a satisfactory electron transport characteristic may be obtained without a substantial increase in driving voltage.

When the electron transport regions 230 to 235 include the electron injection layer 235 , the electron transport regions 230 to 235 select a metal material that facilitates electron injection, LiF, Lithium quinolate (LiQ), Li ₂ O, a lanthanide metal such as BaO, NaCl, CsF, Yb, or a metal halide such as RbCl or RbI may be used, but is not limited thereto.

The electron injection layer 235 may also be made of a material in which an electron transport material and an insulating organo metal salt are mixed. The organometallic salt may be a material having an energy band gap of about 4 eV or more. Specifically, for example, the organometallic salt may include metal acetate, metal benzoate, metal acetoacetate, metal acetylacetonate or metal stearate. can The electron injection layers 235 may have a thickness of about 1 Å to about 100 Å, or about 3 Å to about 90 Å. When the thickness of the electron injection layers 235 satisfies the above-described range, a satisfactory electron injection characteristic may be obtained without a substantial increase in driving voltage.

As described above, the electron transport regions 230 to 235 may include a hole blocking layer. The hole blocking layer includes, for example, at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), and Balq. can, but is not limited thereto.

The second electrode 120 is provided on the electron transport regions 230 to 235 . The second electrode 120 may be a common electrode or a cathode. The second electrode 120 may be a transmissive electrode or a transflective electrode. Unlike the first electrode 110 , the second electrode 120 may use a combination of a metal, an electrically conductive compound, an alloy, etc. having a relatively low work function.

The second electrode 120 is a transflective electrode or a reflective electrode. The second electrode 120 includes Li (lithium), Mg (magnesium), Al (aluminum), Al-Li (aluminum-lithium), Ca (calcium), Mg-In (magnesium-indium), and Mg-Ag (magnesium). -silver) or a compound or mixture containing them (eg, a mixture of Ag and Mg). or a plurality of layer structures including a reflective or semi-transmissive film formed of the above material and a transparent conductive film formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc. can be

Although not shown, the second electrode 120 may be connected to the auxiliary electrode. When the second electrode 120 is connected to the auxiliary electrode, the resistance of the second electrode 120 may be reduced.

An electrode and an organic material layer are formed on the illustrated substrate 100. In this case, the substrate 100 may use a rigid or flexible material, for example, soda lime glass, alkali-free glass, aluminosilicate glass as the rigid material. PC (polycarbonate), PES (polyether sulfone), COC (cyclic oliphene copolymer), PET (polyethylene terephthalate), PEN (polyethylene naphthalate), etc. can be used as a soft material. .

In the organic light emitting device, as a voltage is applied to each of the first electrode 110 and the second electrode 120 , holes injected from the first electrode 110 pass through the hole transport regions 210 to 215 to the emission layer The electrons are moved to 220 , and the electrons injected from the second electrode 120 are moved to the emission layer 220 through the electron transport regions 230 to 235 . Electrons and holes recombine in the emission layer 220 to generate excitons, and the excitons fall from the excited state to the ground state and emit light.

The optical path generated by the light emitting layer 220 may exhibit a very different tendency according to the refractive index of the organic/inorganic materials constituting the organic light emitting device. Light passing through the second electrode 120 may pass only light transmitted at an angle smaller than the critical angle of the second electrode 120 . Lights contacting the second electrode 120 larger than the other critical angles are totally reflected or reflected, so that they are not emitted to the outside of the organic light emitting diode.

When the refractive index of the capping layer 300 is high, it contributes to the improvement of luminous efficiency by reducing total reflection or reflection, and also, when it has an appropriate thickness, it contributes to high efficiency improvement and color purity by maximizing the micro-cavity phenomenon .

The capping layer 300 is located at the outermost part of the organic light emitting device, and has a great influence on device characteristics without affecting the driving of the device at all. Therefore, the capping layer 300 is important both in terms of both an internal protection role of the organic light emitting device and improvement of device characteristics. Organic materials absorb light energy in a specific wavelength region, which depends on the energy band gap. If this energy bandgap is adjusted for the purpose of absorbing the UV region that can affect the organic materials inside the organic light emitting device, the capping layer 300 can be used for the purpose of protecting the organic light emitting device including improving optical properties. have.

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

Hereinafter, examples will be given to describe the present specification in detail. However, the embodiments according to the present specification may be modified in various other forms, and the scope of the present application is not to be construed as being limited to the embodiments described below. The embodiments of the present application are provided to more completely explain the present specification to those of ordinary skill in the art.

[Example]

intermediate Synthesis example 1: Synthesis of Intermediate (1)

2-(3-bromophenyl)-4,6-diphenyl-1,3,5-triazine (2-(3-bromophenyl)-4,6-diphenyl-1,3,5-triazine) 10.0 g (25.7 mmol), Benzophenone imine 5.1 g (28.3 mmol), Pd(dba) ₂ 0.4 g (0.8 mmol), BINAP 0.9 g (1.5 mmol), tert -butoxysodium 5.4 g (56.5 mmol) , a mixture of 200 mL of toluene was stirred under reflux for 15 hours. The reaction mixture was cooled to room temperature, passed through a celite pad, and the filtrate was concentrated under reduced pressure. After the obtained compound was suspended in 300 mL of tetrahydrofuran, 100 mL of a 6N hydrochloric acid solution was slowly added thereto, followed by stirring at room temperature for 1 hour. The resulting precipitate was filtered under reduced pressure and washed with tetrahydrofuran. The filtered solid was suspended in 200 mL of water, basified with a saturated sodium carbonate solution (pH>8), and then stirred at room temperature for 1 hour. The precipitate was filtered under reduced pressure, washed with water, and dried to obtain 8.0 g (yield: 96.4%) of a white solid compound (Intermediate (1)).

intermediate Synthesis example 2: Synthesis of intermediate (2)

4-(3-bromophenyl)-2,6-diphenyl-pyrimidine (4-(3-bromophenyl)-2,6-diphenylpyrimidine) 10.0 g (25.8 mmol), Benzophenone imine 5.1 g A mixture of (28.4 mmol), Pd(dba) ₂ 0.5 g (0.8 mmol), BINAP 0.9 g (1.5 mmol), tert -butoxysodium 5.0 g (51.6 mmol), and toluene 100 mL was stirred under reflux for 12 hours. The reaction mixture was cooled to room temperature, diluted with 100 mL of toluene, and washed twice with 200 mL of water. The organic layer was separated, dried over anhydrous sodium sulfate, filtered and concentrated. The concentrated residue was dissolved in 100 mL of tetrahydrofuran, 5 mL of 6N hydrochloric acid was slowly added thereto, and the mixture was stirred at 50 °C for 1 hour. After cooling to room temperature, the obtained solid was filtered under reduced pressure and washed with acetone. The filtered wet body was suspended in 200 mL of water, and the acidity was adjusted to 8 or higher by adding saturated sodium carbonate solution, followed by stirring for 1 hour. The resulting precipitate was filtered, washed with water, and dried under reduced pressure to obtain 7.4 g (yield: 88.7%) of a white solid compound (intermediate (2)).

Various tertiary amine derivatives were synthesized as follows using the synthesized intermediate compound.

Example 1: Synthesis of compound 3-3 (LT19-30-181)

Intermediate (1) 3.5 g (10.8 mmol), 1-bromo-4- (trifluoromethyl) benzene {1-bromo-4- (trifluoromethyl) benzene} 5.3 g (23.7 mmol), tert -butoxysodium A mixture of 3.1 g (32.4 mmol), Pd(dba) ₂ 0.4 g (0.7 mmol), tri- tert -butylphosphine 0.4 g (0.9 mmol, 50wt% toluene solution) and 150 mL of xylene was stirred under reflux for 12 hours. did. The reaction mixture was cooled to room temperature and then concentrated under reduced pressure. To the resulting mixture, 500 mL of chloroform was added, stirred, and filtered through a pad of Celite. The filtrate was concentrated under reduced pressure, and the obtained compound was purified by column chromatography to obtain 2.3 g (yield: 34.8%) of a light green solid compound 3-3 (LT19-30-181).

Example 2: Synthesis of compound 3-4 (LT19-30-137)

Intermediate (1) 2.0 g (6.2 mmol), 1-bromo-3,5-bis (trifluoromethyl) benzene (1-bromo-3,5-bis (trifluoromethyl) benzene) 3.8 g (12.9 mmol), A mixture of 0.4 g (0.6 mmol) of Pd(dba) ₂ , 3.5 g (36.9 mmol) of sodium tert -butoxy, 1.0 g of tri-tert -butylphosphine (2.5 mmol, 50 wt% toluene solution) and 50 mL of xylene The mixture was stirred at reflux for 12 hours. The reaction mixture was cooled to room temperature, diluted with 100 mL of chloroform, and washed with water. The organic layer was separated, dried over anhydrous magnesium sulfate, concentrated under reduced pressure, and the obtained compound was purified by column chromatography to obtain 2.8 g (yield: 61.0%) of a white solid compound 3-4 (LT19-30-137).

Example 3: Synthesis of compound 3-11 (LT19-35-115)

Intermediate (1) 5 g (15.4 mmol), 1-bromo-4-fluorobenzene (1-bromo-4-fluorobenzene) 5.9 g (33.9 mmol), Pd (dba) ₂ 0.3 g (0.5 mmol), tert A mixture of 4.4 g (46.2 mmol) of sodium -butoxy, 0.4 g (1.0 mmol, 50wt% toluene solution) of tri-tert -butylphosphine and 50 mL of xylene was stirred under reflux for 12 hours. The reaction mixture was cooled to room temperature, diluted with 100 mL of chloroform, and washed with water. The organic layer was separated, dried over anhydrous magnesium sulfate, concentrated under reduced pressure, and the obtained compound was purified by column chromatography to obtain 2.9 g (yield: 36.7%) of a white solid compound 3-11 (LT19-35-115).

Example 4: Synthesis of compound 3-12 (LT19-35-117)

Intermediate (1) 5 g (15.4 mmol), 2-bromo-1,3-difluorobenzene (2-bromo-1,3-difluorobenzene) 6.5 g (33.9 mmol), Pd (dba) ₂ 0.3 g ( 0.5 mmol), tert -butoxysodium 4.4 g (46.2 mmol), tri- tert -butylphosphine 0.4 g (1.0 mmol, 50wt% toluene solution) and 50 mL of xylene were stirred under reflux for 12 hours. The reaction mixture was cooled to room temperature, diluted with 100 mL of chloroform, and washed with water. The organic layer was separated, dried over anhydrous magnesium sulfate, concentrated under reduced pressure, and the obtained compound was purified by column chromatography to obtain 0.6 g (yield: 7.1%) of a white solid compound 3-12 (LT19-35-117).

Example 5: Synthesis of compound 3-18 (LT19-30-202)

Intermediate (1) 5 g (15.4 mmol), 1-bromo-2,4,5-trifluorobenzene (1-bromo-2,4,5-trifluorobenzene) 9.8 g (46.2 mmol), Pd (dba) _{2 A} mixture of 0.3 g (0.5 mmol), tert -butoxysodium 4.4 g (45.6 mmol), tri- tert -butylphosphine 1.5 g (3.7 mmol, 50 wt% toluene solution), and xylene 20 mL was refluxed for 12 hours. stirred. The reaction mixture was cooled to room temperature, diluted with 300 mL of chloroform, and washed with water. The organic layer was separated, dried over anhydrous magnesium sulfate, concentrated under reduced pressure, and the obtained compound was purified by column chromatography. The obtained compound was recrystallized from toluene to obtain 0.96 g (yield: 10.6%) of white solid compound 3-18 (LT19-30-202).

Example 6: Synthesis of compound 3-26 (LT19-35-180)

Intermediate (1) 5 g (15.4 mmol), 2-bromo-2,3,4,5,6-pentafluorobenzene (1-bromo-2,3,4,5,6-pentafluorobenzene) 11.4 g ( 46.2 mmol), Pd(dba) ₂ 0.5 g (0.8 mmol), tert -butoxysodium 4.4 g (46.2 mmol), tri- tert -butylphosphine 0.6 g (1.6 mmol, 50 wt% toluene solution) and xylene 50 mL of the mixture was stirred at reflux for 12 h. The reaction mixture was cooled to room temperature, diluted with 100 mL of chloroform, and washed with water. The organic layer was separated, dried over anhydrous magnesium sulfate, concentrated under reduced pressure, and the obtained compound was purified by column chromatography to obtain 0.9 g of a white solid compound 3-26 (LT19-35-180) (yield: 8.9%).

Example 7: Synthesis of compound 3-27 (LT19-35-220)

Intermediate (1) 3.5 g (10.8 mmol), 4- (bromophenyl) trimethylsilane ((4-bromophenyl) trimethylsilane) 5.4 g (23.7 mmol), tert -sodium butoxy A mixture of 3.1 g (32.4 mmol), Pd(dba) ₂ 0.4 g (0.7 mmol), tri- tert -butylphosphine 0.4 g (0.9 mmol, 50wt% toluene solution) and 150 mL of xylene was stirred under reflux for 12 hours. did. The reaction mixture was cooled to room temperature and then concentrated under reduced pressure. To the resulting mixture, 500 mL of chloroform was added, stirred, and filtered through a pad of Celite. The filtrate was concentrated under reduced pressure, and the obtained compound was purified by column chromatography to obtain 4.6 g (yield: 68.6%) of a white solid compound 3-27 (LT19-35-220).

Example 8: Synthesis of compound 4-4 (LT19-35-209)

Intermediate (2) 3.5 g (10.8 mmol), 1-bromo-3,5-bis (trifluoromethyl) benzene (1-bromo-3,5-bis (trifluoromethyl) benzene) 6.9 g (23.7 mmol), tert - sodium butoxy A mixture of 3.1 g (32.4 mmol), Pd(dba) ₂ 0.4 g (0.7 mmol), tri- tert -butylphosphine 0.4 g (0.9 mmol, 50wt% toluene solution) and 150 mL of xylene was stirred under reflux for 12 hours. did. The reaction mixture was cooled to room temperature and then concentrated under reduced pressure. To the resulting mixture, 500 mL of chloroform was added, stirred, and filtered through a pad of Celite. The filtrate was concentrated under reduced pressure, and the obtained compound was purified by column chromatography to obtain 5.4 g (yield: 66.9%) of a white solid compound 4-4 (LT19-35-209).

Example 9: Synthesis of compound 4-11 (LT19-35-227)

Intermediate (2) 3.5 g (10.8 mmol), 1-bromo-4-fluorobenzene (1-bromo-4-fluorobenzene) 4.1 g (23.7 mmol), tert-butoxysodium A mixture of 3.1 g (32.4 mmol), Pd(dba) ₂ 0.4 g (0.7 mmol), tri- tert -butylphosphine 0.4 g (0.9 mmol, 50wt% toluene solution) and 150 mL of xylene was stirred under reflux for 12 hours. did. The reaction mixture was cooled to room temperature and then concentrated under reduced pressure. To the resulting mixture, 500 mL of chloroform was added, stirred, and filtered through a pad of Celite. The filtrate was concentrated under reduced pressure, and the obtained compound was purified by column chromatography to obtain 2.8 g (yield: 50.7%) of a white solid compound 4-11 (LT19-35-227).

comparative example : compound of Ref02 (LT19-30-381) synthesis

Intermediate (1) 3.0 g (9.2 mmol), bromobenzene, Pd (dba) ₂ 0.5 g (0.9 mmol), tert -butoxysodium 5.1 g (52.9 mmol), tri- tert -butylphosphine 1.4 g (3.5 mmol, 50wt% toluene solution) and a mixture of 100 mL of toluene was stirred at reflux for 16 hours. The reaction mixture was cooled to room temperature, diluted with 300 mL of dichloromethane, and washed with water. The organic layer was separated, dried over anhydrous magnesium sulfate, concentrated under reduced pressure, and the obtained compound was purified by column chromatography to obtain 3.4 g (yield: 77.5%) of a white solid compound Ref02 (LT19-30-381).

<Test Example>

For compounds of the present invention J.A. n (refractive index) and k (extinction coefficient) were measured using WOOLLAM's Ellipsometer.

Single film production for test example:

To measure the optical properties of the compound, a glass substrate (0.7T) is washed in Ethanol, DI Water, and Acetone for 10 minutes each, and then 800Å of the compound is deposited on the glass substrate to prepare a single film.

Single film fabrication for comparative test example (Glass/REF01 (80 nm)):

The optical characteristic device was manufactured by depositing REF01 (80 nm) on glass. Before depositing the compound Glass is 2 × 10 ^- was for 2 minutes in the oxygen plasma treatment ² Torr to 125 W. A single film is manufactured by depositing the compound at a rate of 1 Å/sec in a vacuum of 9×10 ^{- 7 Torr.}

< Test Examples 1 to 9 >

In the comparative test example, a single membrane was manufactured in the same manner as in the comparative test example, except that each compound shown in Table 1 was used instead of using REF01.

Table 1 shows the optical properties of the compounds according to the Comparative Test Examples and Test Examples 1 to 9.

The optical properties are refractive index constants at 460 nm and 620 nm wavelengths.

division compound n (460 nm) n (620 nm) Comparative test example 1 Ref01 1.986 1.846 Comparative test example 2 Ref02
(LT19-30-381) 1.756 1.693 Test Example 1 3-3
(LT19-30-181) 1.591 1.563 Test Example 2 3-4
(LT19-30-137) 1.523 1.486 Test Example 3 3-11
(LT19-35-115) 1.427 1.415 Test Example 4 3-12
(LT19-35-117) 1.483 1.453 Test Example 5 3-18
(LT19-30-202) 1.683 1.633 Test Example 6 3-26
(LT19-35-180) 1.583 1.551 Test Example 7 3-27
(LT19-35-220) 1.591 1.563 Test Example 8 4-4
(LT19-35-209) 1.468 1.443 Test Example 9 4-11
(LT19-35-227) 1.483 1.453

As can be seen from Table 1, n values in the blue region (460 nm) and the red region (620 nm) of Comparative Test Example 2 (REF02) were 1.756 and 1.693, respectively, and most of the compounds according to the present invention were generally It was confirmed to have a lower refractive index than the comparative test example compound (REF01 or REF02) in the blue region, the green region and the red region. This satisfies the low refractive index value required to secure a high viewing angle in the blue region.

<Example>

device fabrication

For device fabrication, ITO, a transparent electrode, was used as the anode layer, 2-TNATA for the hole injection layer, NPB for the hole transport layer, αβ-ADN for the host of the emission layer, Pyrene-CN for the blue fluorescent dopant, and Liq for the electron injection layer. , Mg:Ag was used as the negative electrode. The structures of these compounds are as follows.

Comparative Example 1 (Capping layer consists of one layer): ITO / 2-TNATA (60 nm) / NPB (20 nm) / αβ-ADN: 10% Pyrene-CN (30 nm) / Alq ₃ (30 nm) / Liq (2 nm) / Mg:Ag (1:9, 10 nm) / REF01 (80 nm)

Comparative Example 2 (Capping layer consists of two layers): ITO / 2-TNATA (60 nm) / NPB (20 nm) / αβ-ADN: 10% Pyrene-CN (30 nm) / Alq ₃ (30 nm) / Liq (2 nm) / Mg:Ag (1:9, 10 nm) / REF02 (20 nm) / REF01 (60 nm)

Blue fluorescence organic light emitting device is ITO (180 nm) / 2-TNATA (60 nm) / NPB (20 nm) / αβ-ADN:Pyrene-CN 10% (30 nm) / Alq ₃ (30 nm) / Liq (2 nm) / Mg:Ag (1:9, 10 nm)/REF02 (20 nm)/REF01 (60 nm) in the order of deposition to fabricate a device. Before depositing the organic material, the ITO electrode was ^{subjected to oxygen plasma treatment at 2 × 10 - 2} Torr at 125 W for 2 minutes. The organic material was ^{deposited at a vacuum of 9 × 10 - 7} Torr, Liq was 0.1 Å/sec, αβ-ADN was 0.18 Å/sec, and Pyrene-CN was simultaneously deposited at 0.02 Å/sec, and the remaining organic materials were all 1 Deposited at a rate of Å/sec. The cappim layer materials used in the experiment were selected as REF01 (high refractive index) and REF02 (low refractive index). After the device was fabricated, it was encapsulated in a glove box filled with nitrogen gas to prevent the device from contacting air and moisture. After forming the barrier with 3M's adhesive tape, barium oxide, a moisture absorbent that can remove moisture, was added and a glass plate was attached.

< Examples 1 to 9 >

In Comparative Example 2, a device was manufactured in the same manner as in Comparative Example, except that each compound shown in Table 2 was used instead of REF02.

Table 2 shows the electroluminescence characteristics of the organic light emitting devices prepared in Comparative Examples and Examples 1 to 9.

division compound drive voltage
[V] efficiency
[cd/A] life span
(%) Comparative Example 1 Ref01 sole 4.50 5.10 88.92 Comparative Example 2 Ref02
(LT19-30-381) 4.51 5.10 89.53 Example 1 3-3
(LT19-30-181) 4.47 6.52 98.13 Example 2 3-4
(LT19-30-137) 4.45 6.13 97.45 Example 3 3-11
(LT19-35-115) 4.38 6.23 97.40 Example 4 3-12
(LT19-35-117) 4.40 6.22 98.11 Example 5 3-18
(LT19-30-202) 4.42 6.11 97.54 Example 6 3-26
(LT19-35-180) 4.40 6.25 97.42 Example 7 3-27
(LT19-35-220) 4.41 6.23 97.55 Example 8 4-4
(LT19-35-209) 4.49 5.43 95.55 Example 9 4-11
(LT19-35-227) 4.50 5.36 95.67

From the results of Table 2, a specific tertiary amine derivative compound according to the present invention can be used as a material for a low refractive index capping layer of an organic electronic device including an organic light emitting device, and an organic electronic device including an organic light emitting device using the same It can be seen that it exhibits excellent characteristics in efficiency, driving voltage, and stability. In particular, the compound according to the present invention exhibited high efficiency characteristics due to excellent micro-cavity ability.

The compound of Formula 1 has unexpectedly desirable properties for use as a low refractive index capping layer in an OLED.

The compound of the present invention can be applied to industrial organic electronic device products due to these properties.

However, the above-described synthesis example is an example, and the reaction conditions may be changed as needed. In addition, the compound according to an embodiment of the present invention may be synthesized to have various substituents using methods and materials known in the art. By introducing various substituents into the core structure represented by Formula 1, it may have properties suitable for use in an organic electroluminescent device.

100: substrate, 110: first electrode, 120: second electrode, 200: organic material layer, 210: hole injection layer, 215: hole transport layer, 220: light emitting layer, 230: electron transport layer, 235: electron injection layer, 300: capping layer

Claims (4)

A tertiary amine derivative for a capping layer of an organic electroluminescent device, represented by the following formula (1).
[Formula 1]

In Formula 1,
Ar ₁ and Ar ₂ are each independently an unsubstituted aryl group having 6 or more and 20 or less carbon atoms,
X ₁ , X ₂ and X ₃ are each independently CH or N (at least two or more must be N),
Ar ₃ and Ar ₄ are each independently F, CF ₃ , and Si(CH ₃ ) ₃ It is an aryl group or heteroaryl group having 6 or more and 20 or less carbon atoms, substituted with at least one of them. The method of claim 1,
The compound represented by Formula 1 is a tertiary amine derivative for a capping layer of an organic electroluminescent device represented by Formula 2 below.
[Formula 2]

In Formula 2,
Ar ₁ and Ar ₂ are each independently an unsubstituted aryl group having 6 or more and 12 or less carbon atoms,
X ₁ , X ₂ and X ₃ are each independently CH or N (at least two or more must be N),
R ₁ and R ₂ are each independently at least one selected from _{F, CF 3} and Si(CH ₃ ) _{3 ,}
n ₁ and n ₂ are each independently an integer of 1 or more and 5 or less. The method of claim 1,
Formula 1 is a tertiary amine derivative for a capping layer of an organic electroluminescent device selected from compounds represented by Formulas 3 to 4 below.
[Formula 3]

[Formula 4]

a first electrode;
an organic material layer formed of a plurality of organic material layers disposed on the first electrode;
a second electrode disposed on the organic material layer; and
a capping layer disposed on the second electrode; and
The capping layer is an organic electroluminescent device comprising the tertiary amine derivative according to any one of claims 1 to 3.

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