KR100708699B1 - Difluoro benzonitrile-based compound and organic light-emitting device employing the same - Google Patents

Abstract

The present invention discloses one or more difluorobenzonitrile based compounds in the molecule. The compound can be effectively used as an electron injecting material, an electron transporting material and a hole blocking material suitable for fluorescence and phosphorescent devices of all colors such as red, green, blue and white based on excellent electrical properties and high charge transporting ability. In addition, it is possible to provide an organic light emitting device having high efficiency, low voltage, high brightness, and long life.

Description

Difluorobenzonitrile-based compound and organic light-emitting device employing the same

1A-1C illustrate structures of an organic light emitting diode according to an embodiment of the present invention.

2 illustrates EL emission spectrum of the organic light emitting device according to Example 1 of the present invention.

3 is a graph showing a change in current density according to voltage in the organic light emitting device according to Example 1 of the present invention;

4 is a graph illustrating a change in luminance according to voltage in the organic light emitting diode according to the first exemplary embodiment of the present invention.

The present invention relates to an organic light emitting compound comprising at least one difluorobenzonitrile-based compound in a molecule, and more particularly, can be used as an electron injection layer, an electron transporting layer, a light emitting layer, or a hole blocking layer of an organic light emitting device. It relates to a novel light emitting compound and an organic light emitting device using the same.

Luminescent display devices are attracting attention because they are self-luminous display devices, which have high visibility, wide viewing angle, excellent contrast, and fast response time. The EL element includes an inorganic EL element using an inorganic compound as an emitting layer and an organic EL element using an organic compound, and among these, the organic EL element has the characteristics of luminance, driving voltage and response speed as compared with the inorganic EL element. Much research has been made in that this excellent and multicoloring is possible.

For example, Kodak's research in 1987 ("Appl. Phys. Lett." 51, 913 (1987)) used an alloy of ITO at the anode and magnesium (Mg) silver at the cathode, respectively. as a light-emitting material tris (8-quinolinolato) aluminum complex (Alq ₃₎ for use, and with elements of configuration features separate two layers using a triphenylamine derivative in a hole transport material at an applied voltage of about 10V 1,000cd / m ² A degree of luminescence has been reported. The organic light emitting device has a lamination structure of an electron transporting material and a hole transporting material, and its light emission characteristics are significantly improved as compared with a conventional single layer type device.

The general organic light emitting element is based on a stacked type of an anode / organic light emitting layer / cathode configuration and has a hole injection transport layer and an electron injection layer suitably provided thereon, for example, an anode / hole injection / hole transport layer / organic light emitting layer / cathode; Anode / hole injection layer / hole transport layer / organic light emitting layer / electron injection layer / cathode; And an anode / hole injection layer / hole transport layer / organic light emitting layer / electron transport layer / electron injection layer / cathode. Various organic compounds may be used as the electron injection layer, the electron transport layer, or the like of the stacked element. Light metal complexes represented by tris (8-quinolinorate) aluminum (Alq ₃ ), oxadiazole, triazole, benzimidazole, benzoxazole, benzothiazole (benzothiazole) and the like, but compounds sufficiently satisfactory in the luminance of light emission and durability are not obtained. Among them, Alq ₃ having excellent stability and high electron affinity has been reported to be the best. However, when used in a blue light emitting device, color purity is lowered due to emission due to exciton diffusion.

As such, recent advances for the practical use of organic light emitting devices are remarkable, and their characteristics are low voltage, high brightness, wide variety of light emission wavelengths, high-speed response, and thin light emitting devices. This is essential.

In order to solve the above problems, the present invention relates to the development of a material having electrical stability and high electron transport ability, and excellent durability and prevent crystallization, and all colors such as red, green, blue, white, etc. An object of the present invention is to provide an electron injection and / or electron transport material suitable for fluorescence and phosphorescence devices.

It is another object of the present invention to provide a method for preparing the compound.

In addition, an object of the present invention is to provide an organic light emitting device having high brightness, low voltage and long life using the compound.

In order to achieve the above object, the present invention provides a difluorobenzonitrile compound represented by the following general formula (1):

In the above formula, Ar and Ar1 are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic compound having 4 to 30 carbon atoms,

R ₁ and R ₂ are each independently a hydrogen atom, a halogen, a cyano group, a formyl group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted 4 to 30 carbon atoms. Or an unsubstituted heterocyclic compound, or R ₁ and R ₂ may be bonded to each other to form a ring,

n1 is an integer of 0 to 3,

n2 is an integer of 1-6.

In order to achieve the above another object, the present invention provides a method for producing a difluorobenzonitrile compound represented by the formula (1).

In order to achieve the above another object, in the present invention, in the organic light emitting device comprising an organic film between a pair of electrodes, the organic light emitting device comprising a difluorobenzonitrile compound represented by the formula (1) To provide.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention provides a difluorobenzonitrile compound represented by Formula 1 below:

[Formula 1]

In the above formula, Ar and Ar1 are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic compound having 4 to 30 carbon atoms,

R ₁ and R ₂ are each independently a hydrogen atom, a halogen, a cyano group, a formyl group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, for example, a methyl group, an ethyl group, a butyl group, a t-butyl group, a cyclohexyl group, and the like. , A substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heterocyclic compound having 4 to 30 carbon atoms, or R ₁ and R ₂ may be bonded to each other to form a ring,

n1 is an integer of 0-3, n2 is an integer of 1-6.

The aryl group refers to the remaining atomic groups except for one hydrogen atom in the aromatic hydrocarbon. As a monovalent substituent, the term corresponds to an aliphatic alkyl group. It also includes any combination that is bonded or linked by a lingking group. The linking group includes an aliphatic, aromatic, heterocyclic group or a combination thereof.

The heterocyclic compound is a cyclic organic compound containing hetero atoms, and an element constituting the ring includes oxygen, sulfur, nitrogen, phosphorus, arsenic, and the like, not only carbon atoms, in the ring. Heterocyclic compounds are not only cyclic compounds having heteroatoms, but also aromatics of five-membered and six-membered rings containing heteroatoms, derivative compounds thereof, aromatic compounds having two or more heteroatoms, and heterocyclic benzene rings. And heterocyclic compounds condensed with or heterocyclic.

According to one embodiment of the present invention, Ar and Ar1 are each independently 6 to 30 carbon atoms, preferably 6 to 15 carbon atoms, a substituted or unsubstituted aryl group is a phenyl group, methylphenyl group, dimethyl group, trimethyl group, ethylphenyl group , Ethyl biphenyl group, o-, m- and p-fluorophenyl group, dichlorophenyl group, dicyanophenyl group, trifluoromethoxyphenyl group, o-, m-, and p-tolyl group, o-, m- and p- Cumenyl group, mesityl group, phenoxyphenyl group, (α, α-dimethylbenzene) phenyl group, (N, N'-dimethyl) aminophenyl group, (N, N'-diphenyl) aminophenyl group, pentarenyl group, indenyl group, Naphthyl group, methylnaphthyl group, anthracenyl group, azurenyl group, heptarenyl group, acenaphthylenyl group, phenenalenyl group, fluorenyl group, anthraquinolyl group, methyl anthryl group, phenanthryl group, triphenylene group, pyrene Neyl group, crysenyl group, ethyl-crisenyl group, pisenyl group, perylenyl group, chloroperylenyl group, pentaphenyl group, pentacase Neyl group, tetraphenylenyl group, hexaphenyl group, hexasenyl group, rubisenyl group, coroneyl group, trinaphthylenyl group, heptaphenyl group, heptansenyl group, pyranthrenyl group, ovarenyl group, carbazolyl group, lower alkyl carbide It is one selected from the group consisting of a bazolyl group, a biphenyl group, a lower alkyl biphenyl group, a lower alkoxy biphenyl group, a thiophenyl group, an indolyl group and a pyridyl group, and the lower alkyl and lower alkoxy have 1 to 5 carbon atoms.

More preferably, lower alkyl having 3 or less carbon atoms, lower alkoxy having 3 or less carbon atoms in the 1 to 3 ring aryl groups or their aromatic rings selected from fluorenyl group, carbazolyl group, phenyl group, naphthyl group and phenanthryl group; And an aryl group in which 1 to 3, preferably 1, cyano, phenoxy, phenyl or halogen is substituted.

The substituted or unsubstituted heterocyclic compound having 4 to 30 carbon atoms, preferably 2 to 15 carbon atoms is a 5- or 6-membered ring, and examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom.

Examples of preferred heterocyclic compounds include pyrazole, imidazole, oxazole, thiazole, 1,2,3- or 1,2,4 having two or more hetero atoms. Heterocyclic ring-containing nitrogen-containing 5-membered rings such as triazole, tetrazole, and 1,2,4-, 1,2,5- or 1,3,4-oxadiazole And heterocyclic compounds of nitrogen 6-membered rings such as pyridine, pyridazine, pyrimidine, and triazine.

The novel compounds used in the present invention have high electron transport ability because they have fluorine, an electron withdrawing group, in the structure at both ortho positions of the substituted cyano group in the pyridine ring having high electron affinity. . When these compounds are used as the electron injection layer, the electron transporting layer or the light emitting material of the organic light emitting device, the host material of the light emitting layer and the hole blocking layer, they are driven at a low voltage based on their excellent electron transporting ability, so that they exhibit high emission luminance and emit light for a long time. It is advantageous. In particular, the effect can be further enhanced when the molecule has two or more 2,6-difluorobenzonitrile groups having excellent electron transporting ability. The compounds represented by the formula (1) have a function as an electron injection material, an electron transport material, a hole blocking layer, or a hole transport layer material. Although representative structures of the novel compounds of the present invention are shown below, the present invention should not be limited to these compounds.

The compound of Formula 1 may be selected from compounds represented by the following structural formulas:

Where

n1 is an integer of 0 to 3,

Ar 1 is as defined above, and preferably may be one of the following formulae:

The difluorobenzonitrile-based compound of the present invention may be represented by the following structural formula, but is not limited to the following examples:

The present invention provides a method for preparing a difluorobenzonitrile compound represented by the following Chemical Formula 1, comprising reacting a compound represented by the following Chemical Formula 1A with a compound represented by the following Chemical Formula 1B or a compound represented by the Chemical Formula 1C. to provide:

<Formula 1A>

<Formula 1B>

<Formula 1C>

<Formula 1>

In the above formula, Ar and Ar1 are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic compound having 4 to 30 carbon atoms, and preferably each independently pyrazole and imidazole (imidazole), oxazole, thiazole, triazole (1,2,3- or 1,2,4-), tetrazole, oxadiazole, One selected from the group consisting of pyridine, pyridazine, pyrimidine, triazine and derivatives thereof, X is a halogen compound, preferably Br or Cl,

R ₁ and R ₂ are each independently a hydrogen atom, a halogen, a cyano group, a formyl group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a hetero atom having 4 to 30 carbon atoms. One selected from a ring compound, preferably hydrogen, or a substituted or unsubstituted alkyl group having 1 to 15 carbon atoms, or R ₁ and R ₂ may be bonded to each other to form a ring,

n1 is an integer of 0-3, Preferably it is an integer of 0-2, n2 is an integer of 1-6, Preferably it is an integer of 3 or 4.

The present invention provides an organic light emitting compound having a novel structure having at least one or more difluorobenzonitrile based compounds in a molecule used in an organic light emitting device, and the compound is provided between the anode and the cathode in the organic light emitting device. It can be used as any one of an organic light emitting layer, an electron injection layer, an electron carrying layer, or a hole blocking layer.

Hereinafter, a method of manufacturing an organic light emitting diode according to the present invention will be described.

1A-1C are cross-sectional views illustrating a structure of the present invention and a general organic light emitting display device. First, a material for an anode electrode having a high work function on the substrate is formed by vapor deposition or sputtering and used as an anode. Herein, a substrate used in a conventional organic light emitting (EL) device is used, and a glass substrate or a transparent plastic substrate having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and waterproofness is preferable. In addition, transparent and conductive indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO ₂ ), and zinc oxide (ZnO) are used as the anode electrode material.

Next, a hole injection layer (HIL) material may be formed on the anode by a vacuum deposition method, a spin coating method, a cast method, an LB method, etc., but it is easy to obtain a uniform film quality and difficult to produce pinholes. It is preferable to form by the vacuum evaporation method from such a point. When the hole injection layer is formed by vacuum deposition, the deposition conditions vary depending on the compound used as the material of the hole injection layer, the structure and thermal characteristics of the hole injection layer, and the like. 10 ^-8 to 10 ^-3 torr, a deposition rate of 0.01 to 100 mW / sec, and a film thickness are preferably preferably selected from the range of 10 mV to 5 m. The hole injection layer material is not particularly limited, and TCTA, m, which is a phthalocyanine compound such as copper phthalocyanine disclosed in U.S. Patent No. 4,356,429 or a starburst type amine derivative described in Advanced Material, 6, p.677 (1994). -MTDATA, m-MTDAPB can be used as the hole injection layer.

Next, a hole transport layer (HTL) material may be formed on the hole injection layer by a method such as vacuum deposition, spin coating, cast, LB, etc., but it is easy to obtain a uniform film quality and hardly to generate pinholes. It is preferable to form by the vacuum evaporation method from such a point. In the case of forming the hole transport layer by vacuum deposition, the deposition conditions vary depending on the compound used, but are generally selected from the ranges of conditions almost the same as that of the formation of the hole injection layer. The hole transport layer material is not particularly limited and may be selected from any of known ones used in the hole transport layer. For example, carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1-biphenyl] -4 Conventional amine derivatives having aromatic condensed rings such as 4'-diamine (TPD), N, N'-di (naphthalen-1-yl) -N, N'-diphenyl benzidine (? -NPD), and the like are used. do.

Next, the light emitting layer (EML) material can be formed on the hole transport layer by a method such as vacuum deposition, spin coating, casting, LB, etc., but it is easy to obtain a uniform film quality and hard to generate pinholes. It is preferable to form by the vacuum evaporation method from the point. In the case of forming the light emitting layer by the vacuum deposition method, the deposition conditions vary depending on the compound used, but are generally selected from the range of conditions almost the same as the formation of the hole injection layer. The light emitting layer material is not particularly limited, and as the fluorescent host, Alq ₃ , which is a known material, may be used, and in the case of the dopant, as the fluorescent dopant, IDE102, IDE105, and C545T, available from HAYASHIBARA BIOCHEMICAL LABORATORIES, INC, are available from Idemitsu. The phosphorescent dopant may be a common vacuum deposition (dope) of green phosphorescent dopant Ir (ppy) ₃ which is a known material, F ₂ Irpic which is a blue phosphorescent dopant, and a red phosphorescent dopant RD 61 manufactured by UDC. The doping concentration is not particularly limited, but typically a dopant of 0.01 to 15 w% relative to the host is used. In the case of using the phosphorescent dopant in the light emitting layer, it is preferable to further laminate the hole blocking material (HBL) by vacuum deposition or spin coating in order to prevent the triplet excitons or holes from diffusing into the electron transport layer. At this time, the hole blocking material that can be used is not particularly limited, and may be selected from any of known compounds used as the compound of Formula 1 or the hole blocking material according to the present invention. For example, an oxadiazole derivative, a triazole derivative, a phenanthroline derivative, the hole blocking material described in Unexamined-Japanese-Patent No. 11-329734, etc. are mentioned, Typically, Balq, BCP, etc. are used.

Next, the electron transport layer ETL is formed by a vacuum deposition method, a spin coating method, a casting method, or the like, and is preferably formed by a vacuum deposition method. The electron transport layer material is not particularly limited as it functions to stably transport electrons injected from an electron injection electrode (Cathode), and the compound of Formula 1 or a quinoline derivative according to the present invention, particularly tris (8-quinolinorate) Aluminum (Alq ₃ ) can be used. In addition, an electron injection layer (EIL), which is a material having a function of facilitating injection of electrons from the cathode, may be stacked on the electron transport layer, which does not particularly limit the material. As the electron injection layer may be used a material such as _{LiF, NaCl, CsF, Li 2} O, BaO. The deposition conditions of the hole blocking layer (HBL), the electron transport layer (ETL), and the electron injection layer (EIL) vary depending on the compound used, but are generally selected from the range of conditions almost the same as the formation of the hole injection layer.

Finally, the cathode forming metal is formed on the electron injection layer by a vacuum deposition method or a sputtering method and used as a cathode. Here, as the metal for forming the cathode, a metal, an alloy, an electrically conductive compound having a low work function, and a mixture thereof may be used. Specific examples include lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al-Li), calcium (Ca), magnesium-indium (Mg-In), magnesium-silver (Mg-Ag), and the like. Can be mentioned. In addition, a transmissive cathode using ITO and IZO may be used to obtain the front light emitting device.

The organic light emitting device of the present invention has an anode, a hole injection layer (HIL), an emission layer (EML), an electron transport layer (ETL), an electron injection layer (EIL), a cathode (Cathode) structure shown in Figure 1a-1c In addition to the organic light emitting device, organic light emitting devices having various structures are possible, and it is also possible to further form one or two or more intermediate layers as necessary.

Hereinafter, although the preferable synthesis example and the Example of compound 1 which are typical examples of the organic light emitting compound which has at least 1 or more difluoro benzonitrile-type compound in a side chain in the molecule of this invention are illustrated concretely, this invention demonstrates It is not limited to the example. The compounds of Formula 1 may be useful as electron emitting materials, electron transporting materials and hole blocking materials of blue, green, red fluorescence and phosphorescence as light emitting materials having excellent light emission characteristics and electron transport characteristics, and may also be used as host materials.

Synthesis Example  One

Compound 1

Compound 1 was synthesized through the reaction route of Chemical Scheme 1 below.

Synthesis of Intermediate A

To a solution of 1.4 g (10.0 mmol) of difluorobenzonitrile and diethyl ether (50 mL) was added dropwise 6.0 mL (12.0 mmol) of LDA (Lithium diisopropylamide) at -78 ° C and stirred for 1 hour. 12.5 mL (12.5 mmol) of 1M trimethyltin chloride solution is added to the reaction mixture, the temperature is raised to room temperature and stirred for 1 hour. 5% aqueous sodium hydroxide solution (20 mL) is added and the aqueous layer is neutralized with 3 N aqueous hydrochloric acid solution. The aqueous layer is extracted three times with 20 mL of ethyl acetate. The combined organic layers were dried over magnesium sulfate and the residue obtained by evaporation of the solvent was dried under vacuum to yield 2.0 g of white solid A (yield: 66%).

Synthesis of Compound 1

Intermediate A 1.08 mg (3.6 mmol), 0.227 g (0.72 mmol) of 1,3,5-tribromobenzene was dissolved in 18 mL of DMF, followed by tetrakistriphenylphosphinepalladium (200 mg, 0.18 mmol), K ₂ CO3 (2.48 g, 17.9 mmol) is added and stirred at 120 ° C for 2 hours. The reaction solution was extracted three times with 10 mL of ethyl ether. The combined organic layers were dried over magnesium sulfate, and the residue obtained by evaporation of the solvent was separated and purified by silica gel column chromatography to obtain 159 mg (yield 45%) of compound 1 as a white solid. The structure was confirmed by ¹ H NMR. : ¹ H NMR (CDCl ₃ , 400 MHz) δ (ppm) 7.76 (t, 3H), 7.65 (s, 3H), 7.22 (m, 3H)

Example 1

The anode cut corning 15Ω / cm ² (1200Å) ITO glass substrate into 50mm x 50mm x 0.7mm size and ultrasonically cleaned for 5 minutes in isopropyl alcohol and pure water, and then irradiated with ultraviolet rays for 30 minutes and ozone And the glass substrate was installed in a vacuum deposition apparatus. On the substrate, first, IDE 406, a well-known material well-known as a hole injection layer, was vacuum deposited to form a thickness of 600 Å. Subsequently, 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl (NPB) was vacuum deposited to a thickness of 300 kPa as a hole transporting compound to form a hole transporting layer. After the hole transport layer was formed, Alq ₃ , a known green fluorescent host, and C545T, a known green fluorescent dopant, were simultaneously deposited at a weight ratio of 98: 2 on the hole transport layer to form a light emitting layer having a thickness of 200 kPa. Subsequently, Compound 1 according to the present invention was deposited to an electron transport layer at a thickness of 300 kPa, LiF, which is an alkali metal halide, was deposited to an electron injection layer at a thickness of 10 kPa, and Al was deposited to a thickness of 3000 kPa (cathode electrode). The organic light emitting device as shown in FIG. 1B was manufactured by vacuum deposition at a temperature to form a LiF / Al electrode.

The device had a turn-on voltage of 2.5V, a current density of 29.26mA / cm2 and an emission luminance of 1943cd / m2 at an applied voltage of 6.0V. The color coordinates were (0.30, 0.64) and the emission efficiency was 6.64cd / A. . The EL emission spectrum of this device is shown in FIG.

Comparative Example 1

An organic light emitting device was manufactured in the same manner as in Example 1, except that Alq ₃ , which is a well-known and known substance, was used instead of the compound 1 forming an electron transport layer.

The device had a turn-on voltage of 3.0 V, a current density of 7.77 mA / cm 2, and an emission luminance of 905.5 cd / m 2 at an applied voltage of 6.0 V. The color coordinates of (0.30, 0.64) were 10.55 cd / A. .

As a result of using the compound 1 according to the present invention as an electron transporting layer, the turn-on voltage was reduced by 0.5V, the applied voltage at the same current value was significantly lowered, and the current density was improved due to the improvement of the electron injection and transporting ability. As the characteristic was improved, an increase in luminance value of about 2 times at the same applied voltage was confirmed. As a result, it was possible to achieve a low power consumption organic light emitting device capable of high brightness at a low applied voltage compared to the same brightness. 3 and 4 show comparison results of current density values and luminance values under the same applied voltage.

 The present invention relates to an organic light emitting compound having at least one difluorobenzonitrile derivative as a side chain in a molecule represented by Chemical Formula 1. By using the compound as an electron transporting material of the green fluorescent element to provide an organic light emitting device of low voltage, high brightness having excellent characteristics compared to the existing material.

The compounds according to the present invention can be effectively used as electron injection materials, electron transport materials and hole blocking materials suitable for fluorescence and phosphorescent devices of all colors such as red, green, blue and white based on excellent electrical properties and high charge transport capacity. Can be. In addition, it is possible to provide an organic light emitting device having high efficiency, low voltage, high brightness, and long life.

Claims (15)

Difluorobenzonitrile compound represented by the following formula (1): [Formula 1]

In the above formula, Ar and Ar1 are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic compound having 4 to 30 carbon atoms, R ₁ and R ₂ are each independently a hydrogen atom, a halogen, a cyano group, a formyl group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a hetero atom having 4 to 30 carbon atoms. One selected from a ring compound, or R ₁ and R ₂ may be bonded to each other to form a ring, n1 is an integer of 0 to 3, n2 is an integer of 1-6. According to claim 1, Ar and Ar1 in Formula 1 are each independently a phenyl group, methylphenyl group, dimethyl group, trimethyl group, ethylphenyl group, ethyl biphenyl group, o-, m- and p-fluorophenyl group, dichlorophenyl group, Dicyanophenyl group, trifluoromethoxyphenyl group, o-, m-, and p-tolyl group, o-, m- and p-cumenyl group, mesityl group, phenoxyphenyl group, (α, α-dimethylbenzene) phenyl group, (N, N'-dimethyl) aminophenyl group, (N, N'-diphenyl) aminophenyl group, pentarenyl group, indenyl group, naphthyl group, methylnaphthyl group, anthracenyl group, azurenyl group, heptarenyl group, ace Naphthylenyl group, phenenyl group, fluorenyl group, anthraquinolyl group, methyl anthryl group, phenanthryl group, triphenylene group, pyrenyl group, chrysenyl group, ethyl- chrysenyl group, pisenyl group, perrylenyl group, Chloroperylenyl group, pentaphenyl group, pentacenyl group, tetraphenylenyl group, hexaphenyl group, hexasenyl group, rubisenyl group, coroneyl group, Linaptylenyl group, heptaphenyl group, heptasenyl group, pyrantrenyl group, obarenyl group, carbazolyl group, lower alkyl carbazolyl group, biphenyl group, lower alkyl biphenyl group, lower alkoxybiphenyl group, thiophenyl group, indolyl group And difluorobenzonitrile compound, characterized in that one selected from the group consisting of a pyridyl group. According to claim 1, Ar and Ar1 are each independently pyrazole (pyrazole), imidazole (imidazole), oxazole (thiazole), triazole (triazole) (1,2) , 3- or 1,2,4-), tetrazole, oxadiazole, pyridine, pyridazine, pyrimidine, triazine and derivatives thereof Difluorobenzonitrile compound, characterized in that one selected from the group. The difluorobenzonitrile compound according to claim 1, wherein R ₁ and R ₂ are hydrogen or a substituted or unsubstituted alkyl group having 1 to 15 carbon atoms. The difluorobenzonitrile compound according to claim 1, wherein the compound is selected from compounds represented by the following structural formulas: [Formula 2]

 [Formula 3]

 [Formula 4]

 [Formula 5]

 [Formula 6]

 Where Ar 1 and n 1 are each independently as defined above. The difluorobenzonitrile compound according to claim 5, wherein Ar 1 is one of a group represented by the following formula:

The difluorobenzonitrile compound according to claim 1, wherein the compound is selected from compounds represented by the following structural formulas: [Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

 [Formula 12]

 [Formula 13]

Where Ar 1 and n 1 are each independently as defined above. The difluorobenzonitrile compound according to claim 7, wherein Ar 1 is one of a group represented by the following formula:

The difluorobenzonitrile compound according to claim 1, wherein the compound is selected from compounds represented by the following structural formulas:

 A method for preparing a difluorobenzonitrile compound represented by the following Chemical Formula 1, comprising reacting a compound represented by the following Chemical Formula 1A with a compound represented by the following Chemical Formula 1B or Chemical Formula 1C: <Formula 1A>

<Formula 1B>

<Formula 1C>

<Formula 1>

In the above formula, Ar and Ar1 are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted heterocyclic compound having 4 to 30 carbon atoms, X is a halogen compound, R ₁ and R ₂ are each independently a hydrogen atom, a halogen, a cyano group, a formyl group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a hetero atom having 4 to 30 carbon atoms. One selected from a ring compound, or R ₁ and R ₂ may be bonded to each other to form a ring, n1 is an integer of 0 to 3, n2 is an integer of 1-6. The method of claim 10, wherein Ar and Ar1 are each independently pyrazole, imidazole, oxazole, thiazole, triazole (1,2,3- Or 1,2,4-), tetrazole, oxadiazole, pyridine, pyridazine, pyrimidine, triazine and derivatives thereof One, X is Br or Cl, R ₁ and R ₂ are hydrogen or a substituted or unsubstituted alkyl group having 1 to 15 carbon atoms, n1 is an integer of 0 to 2, n2 is an integer of 3 to 4, the method for producing a difluorobenzonitrile compound. In an organic light emitting device comprising an organic film between a pair of electrodes, An organic light-emitting device, characterized in that the organic film comprises the difluorobenzonitrile compound according to any one of claims 1 to 9. The organic light emitting device according to claim 12, wherein the organic film is an electron injection layer. The organic light-emitting device as claimed in claim 12, wherein the organic film is an electron transport layer, a hole blocking layer or an electron transport layer, and a hole blocking layer. 13. The device of claim 12, wherein the device comprises a first electrode / hole transport layer / light emitting layer / electron transport layer / second electrode, first electrode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / second electrode, or An organic light-emitting device having a structure of a first electrode / hole injection layer / hole transport layer / light emitting layer / hole blocking layer / electron transport layer / electron injection layer / second electrode.

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