KR20190079181A - Organic compounds and organic electro luminescence device comprising the same - Google Patents

Abstract

The present invention relates to a novel compound and an organic electroluminescent device comprising the same. A compound according to the present invention is used for an organic layer, preferably a hole injecting layer, a hole transporting layer, a hole transport auxiliary layer, a light emitting layer, an electron transport layer, or an electron injecting layer of the organic electroluminescent device, thereby being able to improve luminous efficiency, driving voltage, lifespan and the like of the organic electroluminescent device.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic compound and an organic electroluminescent device including the organic compound.

The present invention relates to a novel organic compound that can be used as a material for an organic electroluminescence device and an organic electroluminescence device including the same.

The electroluminescent (EL) devices that led to blue electroluminescence using anthracene single crystals in 1965 were followed up with the observation of organic thin film emission from Bernanose in the 1950s. In 1987, Tang The organic light emitting device having a laminated structure in which the hole layer and the functional layer of the light emitting layer are divided. Thereafter, in order to form a high efficiency and high number of organic electroluminescent devices, each organic material layer has been developed into a form in which each organic material layer has been introduced into the device, leading to the development of specialized materials used therefor.

In the organic electroluminescent device, when a voltage is applied between two electrodes, holes are injected into the organic layer in the anode, and electrons are injected into the organic layer in the cathode. When the injected holes and electrons meet, an exciton is formed. When the exciton falls to the ground state, light is emitted. At this time, the material used as the organic material layer can be classified into a light emitting material, a hole injecting material, a hole transporting material, an electron transporting material, an electron injecting material and the like depending on its function.

The luminescent material can be classified into blue, green and red luminescent materials according to luminescent colors and yellow and orange luminescent materials necessary for realizing better natural colors. Further, in order to increase the color purity and increase the luminous efficiency through energy transfer, a host / dopant system can be used as a light emitting material.

The dopant material can be divided into a fluorescent dopant using an organic material and a phosphorescent dopant using a metal complex compound containing heavy atoms such as Ir and Pt. Since the phosphorescent material can theoretically improve the luminous efficiency four times higher than that of the fluorescent material, studies on the phosphorescent host materials as well as the phosphorescent dopant are being conducted.

To date, NPB, BCP and Alq ₃ have been widely known as the hole injecting layer, the hole transporting layer, the hole blocking layer and the electron transporting layer material, and anthracene derivatives have been reported as the light emitting layer material. Particularly, phosphorescent materials having advantages in terms of efficiency improvement of light emitting materials include blue, green and red dopant materials such as Firpic, Ir (ppy) ₃ , (acac) Ir (btp) ₂ A metal complex compound containing Ir is used. Up to now, 4,4-dicarbazolybiphenyl (CBP) has shown excellent properties as a phosphorescent host material.

However, conventional materials have advantages in terms of light emission characteristics, but their thermal stability is lowered due to a low glass transition temperature, and thus the life of the organic light emitting device is not satisfactory. Therefore, development of materials with higher performance is required.

Korean Patent Publication No. 10-2016-0041745 Korean Patent Publication No. 10-1579490

An object of the present invention is to provide a novel organic compound capable of improving the bonding force between holes and electrons while having a high thermal stability due to a high glass transition temperature.

It is another object of the present invention to provide an organic electroluminescent device including the novel organic compound and exhibiting a low driving voltage and a high luminous efficiency and having an improved lifetime.

In order to achieve the above object, an example of the present invention provides a compound represented by the following formula (1).

In Formula 1,

X is O or S,

L is selected from the group consisting of a single bond, an arylene group having ₆ to ₁₈ carbon atoms and a heteroarylene group having 5 to 18 nuclear atoms,

Ar ₁ to Ar ₂ are the same or different, each independently represent hydrogen, deuterium (D), a halogen, a cyano group, a nitro group, C ₁ ~ alkenyl group of the C ₄₀ alkyl group, C ₂ ~ C ₄₀ of, C ₂ ~ alkynyl group of C _40, C ₃ ~ C ₄₀ cycloalkyl group, the number of nuclear atoms of 3 to 40 of the heterocycloalkyl of the alkyl group, C ₆ ~ C ₆₀ aryl group, the number of nuclear atoms of 5 to 60 heteroaryl group, C ₁ ~ C ₄₀ alkyloxy, C ₆ ~ C ₆₀ aryloxy group, C ₁ ~ C ₄₀ alkyl silyl group, the group C ₆ ~ C ₆₀ aryl silyl, C ₁ ~ group alkylboronic of C _40, C ₆ ~ C the group of boron ₆₀ aryl, C ₆ ~ C ₆₀ aryl phosphine group, is selected from the group consisting of C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ C ₆₀ aryl group of an amine of,

R ₁ to R ₅ are the same or different and each independently represents hydrogen, deuterium (D), halogen, cyano, nitro, amino, C ₁ to C ₄₀ alkyl, C ₂ to C ₄₀ alkenyl , A C ₂ to C ₄₀ alkynyl group, a C ₃ to C ₄₀ cycloalkyl group, a heterocycloalkyl group having 3 to 40 nuclear atoms, a C ₆ to C ₆₀ aryl group, a heteroaryl group having 5 to 60 nuclear atoms, A C ₁ to C ₄₀ alkyloxy group, a C ₆ to C ₆₀ aryloxy group, a C ₁ to C ₄₀ alkylsilyl group, a C ₆ to C ₆₀ arylsilyl group, a C ₁ to C ₄₀ alkylboron group, arylboronic group of C ₆ ~ C _60, C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~, or selected from the group consisting of an aryl amine of the C ₆₀ in, or which adjacent To form a condensed ring,

a, b, c and d are integers of 0 to 5, e is an integer of 0 to 3,

Alkyl groups of the L of the aryl group, a heteroaryl group and Ar _1, Ar ₂ and R ₁ to R _5, an alkenyl group, an alkynyl group, a cycloalkyl group, a heterocycloalkyl group, an aryl group, a heteroaryl group, an alkyloxy group, an aryloxy group, alkylsilyl group, aryl silyl group, an alkyl boron group, an aryl boron group, an aryl phosphine group, aryl phosphine oxide group and an arylamine group each independently selected from deuterium, halogen, cyano group, nitro group, C ₂ ~ C ₄₀ alkenyl group, C ₂ ~ C ₄₀ of the alkynyl group, C ₃ ~ C ₄₀ cycloalkyl group, a number of nuclear atoms of 3 to 40 heterocycloalkyl group, C ₁ ~ C ₄₀ alkyl group, C ₆ ~ C ₆₀ of the aryl group, the nucleus A heteroaryl group having 5 to 60 atoms, a C ₁ to C ₄₀ alkyloxy group, a C ₆ to C ₆₀ aryloxy group, a C ₁ to C ₄₀ alkylsilyl group, a C ₆ to C ₆₀ arylsilyl group, C group of ₁ to alkylboronic of C _40, C ₆ ~ C ₆₀ aryl boron group, C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ C ₆₀ aryl amine group It is unsubstituted or substituted by one substituent at least one selected from the group consisting of, when the plurality of the substituents, which are the same or different from each other.

In addition, the present invention provides an organic electroluminescent device comprising a cathode, a cathode, and at least one organic layer sandwiched between the anode and the cathode, wherein at least one of the organic layers includes a compound represented by Formula 1 A light emitting device is provided.

At least one of the organic layers including one or more compounds represented by Formula 1 may be selected from the group consisting of a hole injecting layer, a hole transporting layer, a light emitting layer, an electron transporting layer, and an electron injecting layer, and the hole transporting layer and / . Here, the compound represented by Formula 1 is a hole transport layer material.

The compound represented by the formula (1) according to an example of the present invention is excellent in thermal stability, carrier transport ability, and light emitting ability, and can be used as an organic material layer material of an organic electroluminescent device.

In addition, when the compound represented by the formula (1) according to an example of the present invention is used as an organic material layer material, an organic electroluminescent device can be manufactured in which aspects such as excellent light emitting performance, driving voltage, lifetime and efficiency are greatly improved, The electroluminescent device can be effectively applied to a full color display panel and the like.

Hereinafter, the present invention will be described in detail.

<New Organic Compound>

The organic compound according to the present invention has a structure in which a substituted or unsubstituted phenyl group is introduced at carbon positions 1 to 4 of dibenzofurane or dibenzothiophene as a basic skeleton and the dibenzofuran or di And a diarylamine is introduced into one of the 6th to 9th positions of the benzothiophene, which is represented by the above formula (1). When the organic electroluminescent device includes the compound represented by Formula 1, the driving voltage of the device is low, the emission efficiency and the current efficiency are high, and the lifetime is long. Here, the carbon position numbers of dibenzofuran or dibenzothiophene are as follows.

(X = O, S)

(X = O, S)

As a host of a conventional organic electroluminescent device, there is known a dibenzofuran compound in which one phenyl group is introduced at a carbon position 4. In this case, the glass transition temperature (Tg) of the compound is higher than that of the conventional organic material layer, and the thermal stability is improved, thereby improving the durability and lifetime characteristics of the device. However, the dibenzofuran compound into which one phenyl group is introduced has a higher driving voltage of the organic electroluminescent device than the conventional organic material layer (Alq3 or CBP) or similar to the conventional one.

In the present invention, four phenyl groups are introduced at the carbon positions 1 to 4 of dibenzofuran or dibenzothiophene to have a sphere form, so that a steric effect is greater than when one phenyl group is introduced Thereby lowering the deposition temperature as well as increasing the glass transition temperature (Tg) and improving the thermal stability. Also, due to the high glass transition temperature (Tg) and the steric effect, the hole transporting property in the blue organic light emitting device can be improved. Therefore, the compound of the present invention can further improve the thermal stability and the hole transportability as compared with the conventional dibenzofuran compounds into which one phenyl group is introduced.

In addition, since diarylamine is introduced into one of carbon positions 6 to 9 of the dibenzofuran or dibenzothiophene to enhance the hole transporting ability, it can serve as a light emitting auxiliary layer. In addition, since the homo-level between the hole transporting layer and the light emitting layer is provided, the movement of the holes is facilitated, and the effect of improving the driving voltage and the efficiency can be obtained. In addition, since the hole is more stable, the effect of improving the lifetime can be obtained.

Therefore, when the compound of Chemical Formula 1 according to the present invention is used as a blue hole transporting material or a blue host material of an organic electroluminescent device, the organic electroluminescent material (for example, CBP, BCP, Alq ₃ ) The driving voltage, light emission and current efficiency, durability and lifetime characteristics of the device can be further improved.

In Formula 1, X is O or S.

R ₁ to R ₅ are the same or different and each independently represents hydrogen, deuterium, a halogen group, a cyano group, a nitro group, an amino group, a C ₁ to C ₄₀ alkyl group, a C ₂ to C ₄₀ alkenyl group, C ₂ ~ C ₄₀ of the alkynyl group, C ₃ ~ C ₄₀ cycloalkyl group, a number of nuclear atoms of 3 to 40 heterocycloalkyl group, C ₆ ~ C ₆₀ aryl group, the number of nuclear atoms of 5 to 60 of the heteroaryl A C ₁ to C ₄₀ alkyloxy group, a C ₆ to C ₆₀ aryloxy group, a C ₁ to C ₄₀ alkylsilyl group, a C ₆ to C ₆₀ arylsilyl group, a C ₁ to C ₄₀ alkyl boron group, C ₆ ~ C group ₆₀ arylboronic of, C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~, or selected from the group consisting of an aryl amine of the C ₆₀ in, or They may be bonded to adjacent groups to form a condensed ring.

The alkyl groups of the R ₁ to R _5, an alkenyl group, an alkynyl group, a cycloalkyl group, a heterocycloalkyl group, an aryl group, a heteroaryl group, an alkyloxy group, an aryloxy group, an alkylsilyl group, an arylsilyl group, an alkyl boronic group A halogen atom, a cyano group, a nitro group, a C ₂ to C ₄₀ alkenyl group, a C ₂ to C ₄₀ alkynyl group, a C ₂ to C ₄₀ alkynyl group, an aryl group, of ₃ ~ C ₄₀ cycloalkyl group, the number of nuclear atoms of 3 to 40 heterocycloalkyl group, C ₁ ~ C ₄₀ alkyl group, C ₆ ~ C ₆₀ aryl group, the number of nuclear atoms of 5 to 60 heteroaryl group, C ₁ ~ of alkyloxy of C _40, C ₆ ~ C ₆₀ of the aryloxy group, an alkyl boronic of C ₁ ~ C ₄₀ alkyl silyl group, the group C ₆ ~ C ₆₀ aryl silyl, C ₁ ~ C ₄₀ group, C ₆ ~ arylboronic group of C _60, C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ substituted 1 or more selected from the group consisting of an aryl amine of the C ₆₀ of the And when the substituent is plural, they are the same as or different from each other.

Preferably, R ₁ to R ₄ are hydrogen or a C ₆ to C ₆₀ aryl group, and R ₅ is selected from the group consisting of hydrogen, a C ₁ to C ₄₀ alkyl group and a C ₆ to C ₆₀ aryl group, or May be bonded to adjacent groups to form a condensed ring.

A, b, c and d are integers of 0 to 5, and e is an integer of 0 to 3. Here, when a to e are 0, the phenyl group is not substituted.

L is selected from the group consisting of a single bond, an arylene group having ₆ to ₁₈ carbon atoms, and a heteroarylene group having 5 to 18 nuclear atoms.

The L arylene group and heteroarylene group are each independently selected from the group consisting of deuterium, a halogen, a cyano group, a nitro group, a C ₂ to C ₄₀ alkenyl group, a C ₂ to C ₄₀ alkynyl group, a C ₃ to C ₄₀ cyclo An alkyl group, a heterocycloalkyl group having 3 to 40 nuclear atoms, a C ₁ to C ₄₀ alkyl group, a C ₆ to C ₆₀ aryl group, a heteroaryl group having 5 to 60 nuclear atoms, a C ₁ to C ₄₀ alkyloxy group , A C ₆ to C ₆₀ aryloxy group, a C ₁ to C ₄₀ alkylsilyl group, a C ₆ to C ₆₀ arylsilyl group, a C ₁ to C ₄₀ alkylboron group, a C ₆ to C ₆₀ arylboron group , C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ C is unsubstituted or substituted by one substituent at least one selected from the ₆₀ group consisting of an aryl amine of the above substituent In case of plural, they are the same or different from each other.

According to one example, L is a single bond or is selected from the group consisting of structures represented by the following formulas L-1 to L-11, but is not limited thereto.

Ar ₁ to Ar ₂ are the same or different from each other and each independently represent hydrogen, deuterium (D), halogen, cyano group, nitro group, C ₁ to C ₄₀ alkyl group, C ₂ to C ₄₀ alkenyl group, C _A C ₃ to C ₄₀ cycloalkyl group, a heterocyclic cycloalkyl group having 3 to 40 nuclear atoms, a C ₆ to C ₆₀ aryl group, a heteroaryl group having 5 to 60 nuclear atoms, a C ₁ to C ₄₀ alkynyl group, ~ C ₄₀ alkyloxy group of, C ₆ ~ aryloxy C _60, C ₁ ~ C ₄₀ alkyl silyl group, C ₆ ~ aryl silyl group of C _60, C ₁ ~ C ₄₀ group of an alkyl boron, C ₆ ~ arylboronic group of C _60, C ₆ ~ C ₆₀ aryl phosphine group, is selected from C ₆ ~ C ₆₀ aryl phosphine oxide group, and the group consisting of C ₆ - C ₆₀ aryl amine of the.

The above Ar ₁ and Ar ₂ may further have a substituent such as an alkyl group, alkenyl group, alkynyl group, cycloalkyl group, heterocycloalkyl group, aryl group, heteroaryl group, alkyloxy group, aryloxy group, alkylsilyl group, A halogen atom, a cyano group, a nitro group, a C ₂ to C ₄₀ alkenyl group, a C ₂ to C ₄₀ alkynyl group, a C ₂ to C ₄₀ alkynyl group, an aryl group, of ₃ ~ C ₄₀ cycloalkyl group, the number of nuclear atoms of 3 to 40 heterocycloalkyl group, C ₁ ~ C ₄₀ alkyl group, C ₆ ~ C ₆₀ aryl group, the number of nuclear atoms of 5 to 60 heteroaryl group, C ₁ ~ of alkyloxy of C _40, C ₆ ~ C ₆₀ of the aryloxy group, an alkyl boronic of C ₁ ~ C ₄₀ alkyl silyl group, the group C ₆ ~ C ₆₀ aryl silyl, C ₁ ~ C ₄₀ group, C ₆ ~ arylboronic group of C _60, C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ substituted 1 or more selected from the group consisting of an aryl amine of the C ₆₀ of the It is unsubstituted or substituted with, in the case of a plurality of the substituents, which are the same or different from each other.

According to one example, Ar ₁ and Ar ₂ each independently may be a substituent selected from the group consisting of the structures represented by Ar-1 to Ar-7 shown below, but the present invention is not limited thereto.

Examples of the compound represented by the formula (1) according to the present invention include compounds represented by any one of the following formulas (2) to (9), but are not limited thereto.

In the above Chemical Formulas 2 to 9,

R ₁ to R ₅ , a to e, L, Ar ₁ and Ar ₂ are each the same as defined in the above formula (1).

The compound represented by the formula (1) according to an example of the present invention described above can be further compound structures composed of the following exemplified compounds A1 to A91 and B1 to B91. However, the compounds represented by formula (1) of the present invention are not limited by the following examples.

In the present invention, "alkyl" means a monovalent substituent derived from a linear or branched saturated hydrocarbon having 1 to 40 carbon atoms. Examples thereof include, but are not limited to, methyl, ethyl, propyl, isobutyl, sec-butyl, pentyl, iso-amyl and hexyl.

In the present invention, "alkenyl" means a monovalent substituent derived from a straight-chain or branched-chain unsaturated hydrocarbon having 2 to 40 carbon atoms and having at least one carbon-carbon double bond. Examples thereof include, but are not limited to, vinyl, allyl, isopropenyl, 2-butenyl, and the like.

In the present invention, "alkynyl" means a monovalent substituent derived from a straight-chain or branched-chain unsaturated hydrocarbon having 2 to 40 carbon atoms and having at least one carbon-carbon triple bond. Examples thereof include, but are not limited to, ethynyl, 2-propynyl and the like.

"Aryl" in the present invention means a monovalent substituent derived from an aromatic hydrocarbon having 6 to 40 carbon atoms in which a single ring or two or more rings are combined. Also, a form in which two or more rings are pendant or condensed with each other may be included. Examples of such aryl include, but are not limited to, phenyl, naphthyl, phenanthryl, anthryl and the like.

"Heteroaryl" in the present invention means a monovalent substituent derived from a monoheterocyclic or polyheterocyclic aromatic hydrocarbon having 5 to 40 nuclear atoms. Wherein at least one of the carbons, preferably one to three carbons, is replaced by a heteroatom such as N, O, S or Se. In addition, a form in which two or more rings are pendant or condensed with each other may be included, and further, a condensed form with an aryl group may be included. Examples of such heteroaryls include 6-membered monocyclic rings such as pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, phenoxathienyl, indolizinyl, indolyl indolyl), purinyl, quinolyl, benzothiazole, carbazolyl, and heterocyclic rings such as 2-furanyl, N-imidazolyl, 2- , 2-pyridinyl, 2-pyrimidinyl, and the like, but are not limited thereto.

In the present invention, "aryloxy" means a monovalent substituent represented by RO-, and R represents aryl having 5 to 40 carbon atoms. Examples of such aryloxy include, but are not limited to, phenyloxy, naphthyloxy, diphenyloxy, and the like.

In the present invention, "alkyloxy" means a monovalent substituent group represented by R'O-, wherein R 'represents alkyl having 1 to 40 carbon atoms, and may be a linear, branched or cyclic structure . &Lt; / RTI &gt; Examples of alkyloxy include, but are not limited to, methoxy, ethoxy, n-propoxy, 1-propoxy, t-butoxy, n-butoxy and pentoxy.

"Arylamine" in the present invention means an amine substituted with aryl having 6 to 40 carbon atoms.

"Cycloalkyl" in the present invention means a monovalent substituent derived from a monocyclic or polycyclic non-aromatic hydrocarbon having 3 to 40 carbon atoms. Examples of such cycloalkyls include, but are not limited to, cyclopropyl, cyclopentyl, cyclohexyl, norbornyl, adamantine, and the like.

"Heterocycloalkyl" in the present invention means a monovalent substituent derived from a non-aromatic hydrocarbon having 3 to 40 nuclear atoms, wherein at least one of the carbons, preferably one to three carbons, Or &lt; RTI ID = 0.0 &gt; Se. &Lt; / RTI &gt; Examples of such heterocycloalkyl include, but are not limited to, morpholine, piperazine, and the like.

In the present invention, "alkylsilyl" means silyl substituted with alkyl having 1 to 40 carbon atoms, and "arylsilyl" means silyl substituted with aryl having 5 to 40 carbon atoms.

In the present invention, the term "condensed rings" means condensed aliphatic rings, condensed aromatic rings, condensed heteroaliphatic rings, condensed heteroaromatic rings, or a combination thereof.

The compounds of formula (1) according to one embodiment of the present invention can be synthesized in various ways with reference to synthesis examples. Detailed synthesis of the compound of the present invention will be described in detail in Synthesis Examples to be described later.

&Lt; Organic electroluminescent device &

Another aspect of the present invention relates to an organic electroluminescent device comprising a compound represented by the above-mentioned formula (1).

Specifically, the organic electroluminescent device according to the present invention includes an anode, a cathode, and at least one organic layer sandwiched between the anode and the cathode, wherein at least one of the one or more organic layers includes Include compounds represented by the above formula (1). At this time, the compounds may be used alone or in combination of two or more.

According to an example, the one or more organic layers may be at least one of a hole injecting layer, a hole transporting layer, a light emitting layer, an electron transporting layer, and an electron injecting layer, and at least one organic layer may include a compound represented by Formula 1 have. Preferably, the organic material layer containing the compound of Formula 1 may be a light emitting layer and / or a hole transporting layer, and more preferably a hole transporting layer material. In addition, it is also preferable to include a light-emission-assisting layer composed of the compound represented by the formula (1) between the hole transporting layer and the light-emitting layer. The compound may be a phosphorescent light-emitting auxiliary layer material.

The structure of the organic electroluminescent device according to the present invention is not particularly limited. For example, the organic electroluminescent device according to the present invention may have a structure in which one or more organic layers are laminated between electrodes. Non-limiting examples thereof include (i) an anode, a light emitting layer, a cathode; (Ii) an anode, a hole injecting layer, a hole transporting layer, a light emitting layer, an electron transporting layer, an electron injecting layer, a cathode; Or (iii) a structure such as an anode, a hole injecting layer, a hole transporting layer, a light emitting layer, and a cathode.

In addition, the organic electroluminescent device according to the present invention may have an insulating layer or an adhesive layer interposed between the electrode and the organic layer, as well as the structure in which the anode, one or more organic layers and the cathode are sequentially stacked, as described above.

The organic electroluminescent device according to the present invention can be manufactured by using materials and methods known in the art, except that at least one layer of the organic material layer includes the compound represented by the formula (1) &Lt; / RTI &gt;

The organic material layer containing the compound represented by Formula 1 may be formed by a vacuum deposition method or a solution coating method. Examples of the solution coating method include, but are not limited to, spin coating, dip coating, doctor blading, inkjet printing, or thermal transfer.

The substrate usable in the present invention is not particularly limited, and examples thereof include silicon wafers, quartz, glass plates, metal plates, plastic films and sheets.

Examples of the positive electrode material include metals such as vanadium, chromium, copper, zinc, and gold, or alloys thereof; Metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); ZnO: Al or SnO _2: a combination of a metal and an oxide such as Sb; Conductive polymers such as polythiophene, poly (3-methylthiophene), poly [3,4- (ethylene-1,2-dioxy) thiophene] (PEDT), polypyrrole or polyaniline; And carbon black, but are not limited thereto.

Examples of the negative electrode material include metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin or lead or alloys thereof; And multi-layer structure materials such as LiF / Al or LiO ₂ / Al, but are not limited thereto.

The hole injecting layer, the hole transporting layer, the light emitting layer, the electron injecting layer and the electron transporting layer are not particularly limited, and ordinary materials known in the art can be used.

Hereinafter, the present invention will be described in detail with reference to examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

[Preparation Example 1] Synthesis of Core-1

&Lt; Step 1 > 6'- chloro -3 ', 4', 5'- 트리 피닐 - [1,1 ': 2', 1 &quot; - 테 페렌 ]-2- ol  synthesis

(2-hydroxyphenyl) boronic acid (14 g, 100 mmol) and 3 ', 4'-Dichloro-5', 6'- diphenyl-1,1 ': 2', 1 " ) And Pd (PPh ₃ ) ₄ (4.6 g, 4 mmol) and NaOH (12 g, 300 mmol) were added to 500 ml THF and 200 ml H ₂ O and stirred at 75 ° C for 8 hours. After completion of the reaction, the reaction mixture was extracted with ethyl acetate, the organic layer was separated, and water was removed using MgSO ₄ . The solvent was removed from the organic layer from which water had been removed and then purified by column chromatography to obtain 6'-chloro-3 ', 4', 5'-triphenyl- [1,1 ': 2', 1 " ol (50 g, yield 98%) was obtained

^{1 H-NMR: δ 5.35 (} s, 1H), 7.01 (d, 1H), 7.07 (d, 1H), 7.24 (m, 1H), 7.41 (m, 4H), 7.51 (m, 8H), 7.52 ( m, 8 H), 7.62 (d, 1 H)

&Lt; Step 2 > 1,2,3,4- tetraphenyldibenzo [b, d] furan  synthesis

(50 g, 98 mmol) and sodium hydrosulfite (26 g, 147 mmol) were added to a solution of 6'-chloro-3 ', 4', 5'-triphenyl- [1,1 ': 2', 1 " mmol), KOH (8 g, 147 mmol) and tetrabutylammonium bromide (32 g, 98 mmol) were dissolved in 500 ml of DMF and stirred at 140 ° C for 8 hours. After completion of the reaction, the reaction mixture was extracted with methylene chloride, and the mixture was filtered with MgSO ₄ . After removing the solvent of the filtered organic layer, 1,2,3,4-tetraphenyldibenzo [b, d] furan (40 g, yield 87%) was obtained by column chromatography.

^{1 H-NMR: δ 7.32 (} t, 1H), 7.38 (t, 1H), 7.41 (m, 4H), 7.51 (m, 8H), 7.52 (m, 8H), 7.66 (d, 1H), 7.89 ( d, 1 H)

&Lt; Step 3 > (6,7,8,9- tetraphenyldibenzo [b, d] furan -4- yl ) boronic acid

1,2,3,4-tetraphenyldibenzo [b, d] furan (40 g, 85 mmol) was added to 300 ml THF and stirred at -75 ° C. After reaching -75 [deg.] C, 2.5 M n-BuLi (34 ml, 85 mmol) was slowly added. After stirring for about 1 hour, triisopropyl borate (39 ml, 170 mmol) was slowly added. After stirring for about 2 hours, 500 ml 1N HCl was added to terminate the reaction. Then, the organic layer was extracted with ethyl acetate, and water was removed using MgSO ₄ . After the solvent was removed from the organic layer from which water had been removed, MC was added and stirred. The solid was filtered to obtain the target compound (6,7,8,9-tetraphenyldibenzo [b, d] furan-4-yl) boronic acid (35 g, yield 78%).

^{1 H-NMR: δ 2.00 (} s, 2H), 7.38 (t, 1H), 7.41 (m, 4H), 7.50 (d, 1H), 7.51 (m, 8H), 7.52 (m, 8H), 7.89 ( d, 1 H)

<Step 4> Synthesis of Core-1

(2-bromo-3-chlorobenzene (13 g, 68 mmol) and Pd (3 g) were added to a solution of 6,7,8,9-tetraphenyldibenzo [b, d] furan- _{PPh 3) 4 (3.1 g,} 3 mmol), NaOH (8.1 g, 204 mmol) to 200 ml into the THF and 100 ml H ₂ O was stirred at 75 ℃ for 8 hours. after completion of the reaction followed by extraction with Ethyl acetate the organic layer was separated by removing the water by using MgSO _4. after removal of the solvent in the water is removed, the organic layer was purified by column chromatography to give the Core-1 (35 g, 88% yield)

^{1 H-NMR: δ 7.38 (} t, 1H), 7.40 (d, 1H), 7.41 (m, 4H), 7.45 (m, 2H), 7.50 (d, 1H), 7.51 (m, 8H), 7.52 ( m, 8 H), 7.89 (d, 1 H), 8.01 (s, 1 H)

[Preparation Example 2] Synthesis of Core-2

&Lt; Step 1 > 6'- chloro -2-( 메틸 시ulfinyl ) -3 ', 4', 5'- 트리 피닐 -1,1 ': Synthesis of 2', 1 "-terphenyl

(45 g, 100 mmol) and (2- (methylsulfinyl) phenyl) boronic acid (18 g, 10 mmol) were added to a solution of 3 ', 4'-Dichloro-5', 6'- diphenyl- , 100 mmol) and Pd (PPh ₃₎ into a _{4 (4.6 g, 4 mmol)} , NaOH (12 g, 300 mmol) to 500 ml THF and 200 ml H ₂ O was stirred at 75 ℃ for 8 hours. After completion of the reaction, the reaction mixture was extracted with ethyl acetate, and the organic layer was separated and washed with MgSO ₄ . The solvent was removed from the organic layer from which water had been removed and then purified by column chromatography to obtain 6'-chloro-2- (methylsulfinyl) -3 ', 4', 5'- terphenyl (50 g, yield 91%) was obtained

^{1 H-NMR: δ 2.64 (} s, 3H), 7.01 (d, 1H), 7.07 (d, 1H), 7.24 (m, 1H), 7.41 (m, 4H), 7.51 (m, 8H), 7.52 ( m, 8 H), 7.62 (d, 1 H)

&Lt; Step 2 > 1,2,3,4- tetraphenyldibenzo [b, d] thiophene  synthesis

100 ml of sulfuric acid was added to 6'-chloro-2- (methylsulfinyl) -3 ', 4', 5'-triphenyl-1,1 ': 2', 1 "-terphenyl (50 g, Lt; / RTI &gt; After completion of the reaction, 500 ml of a 1N NaOH solution was added and the mixture was stirred for 1 hour. The resulting solid was filtered and then recrystallized using toluene to obtain the target compound, 1,2,3,4-tetraphenyldibenzo [b, d] thiophene (40 g, yield 91%).

^{1 H-NMR: δ 7.32 (} t, 1H), 7.38 (t, 1H), 7.41 (m, 4H), 7.51 (m, 8H), 7.52 (m, 8H), 7.66 (d, 1H), 7.98 ( d, 1 H)

&Lt; Step 3 > (6,7,8,9- tetraphenyldibenzo [b, d] thiophen -4- yl ) boronic acid

1,2,3,4-tetraphenyldibenzo [b, d] furan (40 g, 82 mmol) was added to 300 ml of THF and stirred at -75 ° C. After reaching -75 [deg.] C, 2.5 M n-BuLi (33 ml, 82 mmol) was slowly added. After stirring for about 1 hour, triisopropyl borate (38 ml, 164 mmol) was slowly added. After stirring for about 2 hours, 500 ml 1N HCl was added to terminate the reaction. Then, the organic layer was extracted with ethyl acetate, and water was removed using MgSO ₄ . After the solvent was removed from the organic layer from which water had been removed, MC was added and stirred. The solid was filtered to obtain the target compound (6,7,8,9-tetraphenyldibenzo [b, d] thiophen-4-yl) boronic acid (35 g, yield 80%).

^{1 H-NMR: δ 2.00 (} s, 2H), 7.38 (t, 1H), 7.41 (m, 4H), 7.50 (d, 1H), 7.51 (m, 8H), 7.52 (m, 8H), 7.98 ( d, 1 H)

<Step 4> Synthesis of Core-2

(2-bromo-3-chlorobenzene (13 g, 66 mmol) and Pd (3 g) were added to a solution of 6,7,8,9-tetraphenyldibenzo [b, d] thiophen- _{PPh 3) 4 (2.6 g,} 3 mmol), placed in NaOH (7.9 g, 198 mmol) to 200 ml THF and 100 ml H ₂ O was stirred at 75 ℃ for 8 hours. the reaction organic layer was extracted with Ethyl acetate after completion the water was removed using MgSO ₄ and then removed. after removal of the solvent in the water is removed, the organic layer was purified by column chromatography to give the Core-2 (30 g, yield 76%)

^{1 H-NMR: δ 7.38 (} t, 1H), 7.40 (d, 1H), 7.41 (m, 4H), 7.45 (m, 2H), 7.50 (d, 1H), 7.51 (m, 8H), 7.52 ( m, 8H), 8.01 (s, IH), 8.20 (d, IH)

[ Synthetic example  1] Synthesis of Compound A-43

Core-1 (5.0 g, 8.6 mmol), diphenylamine (1.5 g, 8.6 mmol) and _{Pd 2 (dba) 3 (0.3} g, 0.3 mmol), P (t-Bu) 3 (0.1 g, 0.7 mmol), NaOt -Bu (2.5 g, 25.8 mmol) was added to 50 ml of toluene and stirred at 110 for 4 hours. After completion of the reaction, the organic layer was extracted with toluene and water was removed using MgSO ₄ . After removal of the solvent from the organic layer from which water had been removed, the product was purified by column chromatography to obtain Compound A-43 (5 g, 82%).

[LCMS]: 715

[ Synthetic example  2] Synthesis of Compound A-44

(2.1 g, 8.6 mmol) and Pd ₂ (dba) ₃ (0.3 g, 0.3 mmol), P- (1,1'-biphenyl- (t-Bu) ₃ (0.1 g, 0.7 mmol) and NaOt-Bu (2.5 g, 25.8 mmol) were added to 50 ml of toluene and stirred at 110 for 4 hours. After completion of the reaction, the organic layer was extracted with toluene and water was removed using MgSO ₄ . After removal of the solvent from the organic layer from which the water had been removed, the product was purified by column chromatography to obtain Compound A-44 (5 g, 73%).

[LCMS]: 791

[ Synthetic example  3] Synthesis of Compound A-46

Core-1 (5.0 g, 8.6 mmol), N-phenylnaphthalen-2-amine (1.9 g, 8.6 mmol) and _{Pd 2 (dba) 3 (0.3} g, 0.3 mmol), P (t-Bu) 3 (0.1 g , 0.7 mmol) and NaOt-Bu (2.5 g, 25.8 mmol) were added to 50 ml of toluene and the mixture was stirred at 110 for 4 hours. After completion of the reaction, the organic layer was extracted with toluene and water was removed using MgSO ₄ . After removing the solvent from the organic layer from which water had been removed, the product was purified by column chromatography to obtain Compound A-46 (5 g, 76%).

[LCMS]: 765

[ Synthetic example  4] Synthesis of Compound A-48

4-yl) amine (2.8 g, 8.6 mmol) and Pd ₂ (dba) ₃ (0.3 g, 0.3 mmol) were added to a solution of Core-1 (5.0 g, 8.6 mmol) P (t-Bu) ₃ (0.1 g, 0.7 mmol) and NaOt-Bu (2.5 g, 25.8 mmol) were added to 50 ml of toluene and stirred at 110 for 4 hours. After completion of the reaction, the organic layer was extracted with toluene and water was removed using MgSO ₄ . After removal of the solvent from the organic layer from which the water had been removed, the product was purified by column chromatography to obtain Compound A-48 (6 g, 81%).

[LCMS]: 867

[ Synthetic example  5] Synthesis of Compound A-50

(2.2 g, 8.6 mmol) and Pd ₂ (dba) ₃ (0.3 g, 0.3 mmol) and P (t- Bu) ₃ (0.1 g, 0.7 mmol) and NaOt-Bu (2.5 g, 25.8 mmol) were placed in 50 ml of toluene and stirred at 110 for 4 hours. After completion of the reaction, the organic layer was extracted with toluene and water was removed using MgSO ₄ . After removal of the solvent from the organic layer from which the water had been removed, the product was purified by column chromatography to obtain Compound A-50 (5 g, 72%).

[LCMS]: 805

[ Synthetic example  6] Synthesis of Compound B-43

Core-2 (5.2 g, 8.6 mmol), diphenylamine (1.5 g, 8.6 mmol) and _{Pd 2 (dba) 3 (0.3} g, 0.3 mmol), P (t-Bu) 3 (0.1 g, 0.7 mmol), NaOt -Bu (2.5 g, 25.8 mmol) was added to 50 ml of toluene and stirred at 110 for 4 hours. After completion of the reaction, the organic layer was extracted with toluene and water was removed using MgSO ₄ . After removal of the solvent from the organic layer from which water had been removed, the product was purified by column chromatography to obtain Compound B-43 (5 g, 79%).

[LCMS]: 731

[ Synthetic example  7] Synthesis of Compound B-44

(2.1 g, 8.6 mmol) and Pd ₂ (dba) ₃ (0.3 g, 0.3 mmol), P ( ₂ g, (t-Bu) ₃ (0.1 g, 0.7 mmol) and NaOt-Bu (2.5 g, 25.8 mmol) were added to 50 ml of toluene and stirred at 110 for 4 hours. After completion of the reaction, the organic layer was extracted with toluene and water was removed using MgSO ₄ . After removal of the solvent from the organic layer from which water had been removed, the product was purified by column chromatography to obtain Compound B-44 (5 g, 72%).

[LCMS]: 807

[ Synthetic example  8] Synthesis of compound B-46

P (t-Bu) ₃ (0.1 g, 0.3 mmol), Pd ₂ (dba) ₃ (0.3 g, 0.3 mmol) and N-phenylnaphthalen-2-amine (1.9 g, 8.6 mmol) , 0.7 mmol) and NaOt-Bu (2.5 g, 25.8 mmol) were added to 50 ml of toluene and the mixture was stirred at 110 for 4 hours. After completion of the reaction, the organic layer was extracted with toluene and water was removed using MgSO ₄ . After removal of the solvent from the organic layer from which the water had been removed, the product was purified by column chromatography to obtain Compound B-46 (5 g, 75%).

[LCMS]: 781

[ Synthetic example  9] Synthesis of Compound B-48

4-yl) amine (2.8 g, 8.6 mmol) and Pd ₂ (dba) ₃ (0.3 g, 0.3 mmol) P (t-Bu) ₃ (0.1 g, 0.7 mmol) and NaOt-Bu (2.5 g, 25.8 mmol) were added to 50 ml of toluene and stirred at 110 for 4 hours. After completion of the reaction, the organic layer was extracted with toluene and water was removed using MgSO ₄ . After removal of the solvent from the organic layer from which water had been removed, the product was purified by column chromatography to obtain Compound B-48 (5 g, 66%).

[LCMS]: 883

[ Synthetic example  10] Synthesis of Compound B-50

(2.2 g, 8.6 mmol) and Pd ₂ (dba) ₃ (0.3 g, 0.3 mmol), P (t- Bu) ₃ (0.1 g, 0.7 mmol) and NaOt-Bu (2.5 g, 25.8 mmol) were placed in 50 ml of toluene and stirred at 110 for 4 hours. After completion of the reaction, the organic layer was extracted with toluene and water was removed using MgSO ₄ . After removal of the solvent from the organic layer from which the water had been removed, the product was purified by column chromatography to obtain Compound B-50 (5 g, 71%).

[LCMS]: 805

[Example 1] Fabrication of blue organic EL device

Compound A-43 synthesized in Synthesis Example 1 was subjected to high-purity sublimation purification by a conventionally known method, and then a blue organic EL device was manufactured according to the following procedure.

First, a glass substrate coated with ITO (Indium Tin Oxide) with a thickness of 1500 Å was washed with distilled water ultrasonic waves. After the distilled water was washed, the substrate was ultrasonically washed with a solvent such as isopropyl alcohol, acetone, or methanol, dried and transferred to a UV OZONE cleaner (Power Sonic 405, Hoshin Tech), the substrate was cleaned using UV for 5 minutes, The substrate was transferred.

(15 nm) / Compound A-43 (15 nm) / ADN + 5% DS-405 (Doosan) (300 nm) on the ITO transparent electrode thus prepared. / BCP (10 nm) / Alq ₃ (30 nm) / LiF (1 nm) / Al (200 nm) were stacked in this order to fabricate an organic electroluminescent device.

[Examples 2 to 10] Fabrication of blue organic EL device

A-44, A-48, A-50, B-43, B-44, B-46, and B- 48, and B-50, respectively, were prepared in the same manner as in Example 1, to thereby produce a blue organic electroluminescent device.

[Comparative Example 1] Production of blue organic EL device

A blue organic electroluminescent device was manufactured in the same manner as in Example 1, except that the compound Cpd 1 was used in place of the compound A-43 used in Example 1.

[Comparative Example 2] Fabrication of blue organic EL device

A blue organic electroluminescent device was fabricated in the same manner as in Example 1, except that the compound Cpd 2 was used in place of the compound A-43 used in Example 1.

[Comparative Example 3] Fabrication of blue organic EL device

A blue organic electroluminescent device was fabricated in the same manner as in Example 1, except that the luminescent auxiliary layer was not formed.

The structures of NPB, AND, BCP, Cpd 1 and Cpd 2 used in Examples 1 to 10 and Comparative Examples 1 to 3 are as follows.

[ Evaluation example ]

The driving voltage and the current efficiency at a current density of 10 mA / cm 2 were measured for each of the blue organic electroluminescent devices manufactured in Examples 1 to 10 and Comparative Examples 1 to 3, and the results are shown in Table 1 below .

Sample The light- Driving voltage
(V) EL peak
(nm) Current efficiency
(cd / A) Example 1 A-43 5.50 455 6.9 Example 2 A-44 5.50 455 7.0 Example 3 A-46 5.32 455 7.2 Example 4 A-48 5.43 455 7.1 Example 5 A-50 5.41 455 7.0 Example 6 B-43 5.55 455 6.9 Example 7 B-44 5.23 455 6.4 Example 8 B-46 5.24 455 6.3 Example 9 B-48 5.45 455 6.5 Example 10 B-50 5.55 455 6.9 Comparative Example 1 One 5.67 455 6.2 Comparative Example 2 2 5.75 456 6.4 Comparative Example 3 - 6.05 455 5.5

As shown in Table 1, the blue color of Examples 1 to 10 using the compounds represented by Formula 1 (compounds A-1 to A-91, B-1 to B-91) The organic electroluminescent device was composed of the blue organic electroluminescent devices of Comparative Example 1 and Comparative Example 2 which used the compounds Cpd1 and Cpd2 as the light emitting auxiliary layer material and the blue organic electroluminescent devices of Comparative Example 3 which used ADN as the light emitting layer material without the light emitting auxiliary layer It was found that the driving voltage and the current efficiency were superior to those of the device.

Claims (9)

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

In Formula 1,
X is O or S,
L is selected from the group consisting of a single bond, an arylene group having ₆ to ₁₈ carbon atoms and a heteroarylene group having 5 to 18 nuclear atoms,
Ar ₁ to Ar ₂ are the same or different, each independently represent hydrogen, deuterium (D), a halogen, a cyano group, a nitro group, C ₁ ~ alkenyl group of the C ₄₀ alkyl group, C ₂ ~ C ₄₀ of, C ₂ ~ alkynyl group of C _40, C ₃ ~ C ₄₀ cycloalkyl group, the number of nuclear atoms of 3 to 40 of the heterocycloalkyl of the alkyl group, C ₆ ~ C ₆₀ aryl group, the number of nuclear atoms of 5 to 60 heteroaryl group, C ₁ ~ C ₄₀ alkyloxy, C ₆ ~ C ₆₀ aryloxy group, C ₁ ~ C ₄₀ alkyl silyl group, the group C ₆ ~ C ₆₀ aryl silyl, C ₁ ~ group alkylboronic of C _40, C ₆ ~ C the group of boron ₆₀ aryl, C ₆ ~ C ₆₀ aryl phosphine group, is selected from the group consisting of C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ C ₆₀ aryl group of an amine of,
R ₁ to R ₅ are the same or different and each independently represents hydrogen, deuterium (D), halogen, cyano, nitro, amino, C ₁ to C ₄₀ alkyl, C ₂ to C ₄₀ alkenyl , A C ₂ to C ₄₀ alkynyl group, a C ₃ to C ₄₀ cycloalkyl group, a heterocycloalkyl group having 3 to 40 nuclear atoms, a C ₆ to C ₆₀ aryl group, a heteroaryl group having 5 to 60 nuclear atoms, A C ₁ to C ₄₀ alkyloxy group, a C ₆ to C ₆₀ aryloxy group, a C ₁ to C ₄₀ alkylsilyl group, a C ₆ to C ₆₀ arylsilyl group, a C ₁ to C ₄₀ alkylboron group, arylboronic group of C ₆ ~ C _60, C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~, or selected from the group consisting of an aryl amine of the C ₆₀ in, or which adjacent To form a condensed ring,
a, b, c and d are integers of 0 to 5, e is an integer of 0 to 3,
Alkyl groups of the L of the aryl group, a heteroaryl group and Ar _1, Ar ₂ and R ₁ to R _5, an alkenyl group, an alkynyl group, a cycloalkyl group, a heterocycloalkyl group, an aryl group, a heteroaryl group, an alkyloxy group, an aryloxy group, alkylsilyl group, aryl silyl group, an alkyl boron group, an aryl boron group, an aryl phosphine group, aryl phosphine oxide group and an arylamine group each independently selected from deuterium, halogen, cyano group, nitro group, C ₂ ~ C ₄₀ alkenyl group, C ₂ ~ C ₄₀ of the alkynyl group, C ₃ ~ C ₄₀ cycloalkyl group, a number of nuclear atoms of 3 to 40 heterocycloalkyl group, C ₁ ~ C ₄₀ alkyl group, C ₆ ~ C ₆₀ of the aryl group, the nucleus A heteroaryl group having 5 to 60 atoms, a C ₁ to C ₄₀ alkyloxy group, a C ₆ to C ₆₀ aryloxy group, a C ₁ to C ₄₀ alkylsilyl group, a C ₆ to C ₆₀ arylsilyl group, C group of ₁ to alkylboronic of C _40, C ₆ ~ C ₆₀ aryl boron group, C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ C ₆₀ aryl amine group It is unsubstituted or substituted by one substituent at least one selected from the group consisting of, when the plurality of the substituents, which are the same or different from each other. The compound of claim 1, wherein the compound represented by Formula 1 is represented by any one of the following Chemical Formulas 2 to 9:
(2)

(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

[Chemical Formula 9]

In the above Chemical Formulas 2 to 9,
R ₁ to R ₅ , a to e, L, Ar ₁ and Ar ₂ are the same as defined in claim 1, respectively. The method according to claim 1,
Ar ₁ and Ar ₂ are each independently selected from the group consisting of the structures represented by the following Ar-1 to Ar-7.

The method according to claim 1,
Wherein L is a single bond, and a structure represented by the following formulas L-1 to L-11.

The method according to claim 1,
Wherein the compound represented by Formula 1 is selected from the group consisting of the compounds represented by the following Al to B91.

The method according to claim 1,
The compound represented by Formula 1 may be prepared by reacting a compound represented by the following formula A-43, A-44, A-46, A-48, A-50, B-43, B-44, B- Lt; / RTI &gt;

A cathode, and at least one organic layer interposed between the anode and the cathode,
Wherein at least one of the one or more organic layers includes the compound according to any one of claims 1 to 6. 8. The method of claim 7,
Wherein the organic compound layer containing the compound is selected from the group consisting of a hole injecting layer, a hole transporting layer, a light emitting layer, an electron transporting layer, and an electron injecting layer. 8. The method of claim 7,
Wherein the organic electroluminescent device includes a light emitting auxiliary layer between the hole transporting layer and the light emitting layer,
Wherein the light-emission-assisting layer comprises a compound represented by the general formula (1).