KR101506793B1 - Organic electro luminescence device - Google Patents

Abstract

The present invention relates to a positive electrode; cathode; And one or more organic layers sandwiched between the anode and the cathode, wherein at least one of the one or more organic layers includes a first host and a second host that are different from each other.
The organic electroluminescent device according to the present invention can improve various characteristics such as luminous efficiency, driving voltage, and lifetime.

Description

TECHNICAL FIELD [0001] The present invention relates to an organic electroluminescence device,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device including at least one organic material layer, and more particularly, to an organic electroluminescent device having two or more different host materials, will be.

A study on organic electroluminescent (EL) devices (hereinafter simply referred to as 'organic EL devices') led to blue electroluminescence using anthracene single crystals in 1965, starting from the observations of organic thin film emission of Bernanose in the 1950s In 1987, a layered organic EL device was proposed by Tang divided into a hole layer and a functional layer of a light emitting layer. In order to produce high efficiency and high number of organic EL devices, the organic EL device has been developed to introduce each characteristic organic material layer in 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 to increase the luminous efficiency through energy transfer, a host / dopant system can be used as a luminescent 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. At this time, since the phosphorescent material can theoretically improve the luminous efficiency up to 4 times as compared with the fluorescent material, researches on phosphorescent host materials as well as phosphorescent dopants have been conducted.

Up to now, hole injecting layer, hole transporting layer. NPB, BCP, and Alq ₃ are widely known as the hole blocking layer and the electron transporting layer, and anthracene derivatives as a luminescent material have been reported as fluorescent dopant / host material. In particular, the phosphor has a great advantage in improving the efficiency aspects of the light-emitting material materials _{Firpic, Ir (ppy) 3,} (acac) Ir (btp) 2 Ir metal complex compound is blue (blue), which includes the same as the green ( green and red dopant materials, and CBP is a phosphorescent host material.

However, existing materials have an advantage in terms of luminescence properties, but their thermal stability is not very good due to their low glass transition temperature, so that they are not satisfactory in terms of lifetime in OLED devices. Therefore, development of an organic electroluminescent device including a luminescent material having excellent performance is required.

In order to solve the above problems, it is an object of the present invention to provide an organic electroluminescent device with improved driving voltage, luminous efficiency, and life span.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise forms disclosed. .

The present invention relates to a positive electrode; cathode; And one or more organic layers sandwiched between the anode and the cathode, wherein at least one of the one or more organic layers includes a first host and a second host which are different from each other in a ratio of 1:99 to 99: 1 Wherein the first host is a compound represented by Formula 1 and the second host is a hole-transporting compound having a triplet energy of 2.3 eV or more.

In Formula 1,

Y ₁ to Y ₄ are the same or different and each independently N or CR ₃ , wherein _one of Y ₁ and Y ₂ , Y ₂ and Y ₃ , or Y ₃ and Y ₄ is represented by the following formula Bonded to the compound to form a condensed ring,

In the formula (2), the dotted line represents a site where condensation is performed with the compound of the formula (1)

Y ₅ to Y ₈ are the same or different and are each independently N or CR ₄ ,

X ₁ and X ₂ are the same or different, and each independently consisting of O, S, Se, N ( Ar 1), C (Ar 2) (Ar 3) and _{Si (Ar 4) (Ar 5} ) is selected from the group, wherein at least one of X ₁ and X ₂ is N (Ar _1),

R ₁ to R ₄ and Ar ₁ to Ar 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 substituted or unsubstituted C ₁ to C ₄₀ alkyl group , A substituted or unsubstituted C ₂ to C ₄₀ alkenyl group, a substituted or unsubstituted C ₂ to C ₄₀ alkynyl group, a substituted or unsubstituted C ₃ to C ₄₀ cycloalkyl group, a substituted or unsubstituted nuclear atom A substituted or unsubstituted C ₆ to C ₆₀ aryl group, a substituted or unsubstituted heteroaryl group having 5 to 60 ring atoms, a substituted or unsubstituted C ₁ to C ₄₀ aliphatic group, alkyloxy group, a substituted or unsubstituted C ₆ ~ C ₆₀ of the aryloxy group, a substituted or unsubstituted C ₁ ~ C ₄₀ alkyl silyl group, a substituted or unsubstituted C ₆ ~ C ₆₀ aryl silyl group, replacement of the Or an unsubstituted C ₁ to C ₄₀ alkylboron group, a substituted or unsubstituted C ₆ to C ₆₀ arylboron group, a substituted or unsubstituted C ₆ to C _{6 0} of the aryl phosphine group, a substituted or unsubstituted C ₆ ~ C ₆₀ aryl phosphine oxide group, and a substituted or unsubstituted C ₆ ~ C ₆₀ is selected from the group consisting of aryl amines, wherein the R ₁ to R ₄ may combine with adjacent groups to form a condensed ring,

In R ₁ to R ₄ and Ar ₁ to Ar ₅ , an alkyl group, 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, A halogen atom, a cyano group, a nitro group, an amino group, a C ₁ to C ₄₀ alkyl group, a C ₂ to C ₄₀ alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, C ₄₀ to C ₄₀ alkenyl, C ₂ to C ₄₀ alkynyl, C ₃ to C ₄₀ cycloalkyl, heterocyclic cycloalkyl having 3 to 40 nuclear atoms, C ₆ to C ₄₀ aryl, C ₁ -C ₄₀ alkyloxy, C ₆ -C ₆₀ aryloxy, C ₁ -C ₄₀ alkylsilyl, C ₆ -C ₆₀ arylsilyl, C ₁ -C ₄₀ alkyl, the alkyl boron group, the group consisting of C ₆ ~ C ₆₀ aryl group of boron, C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ C ₆₀ aryl amine of the May be substituted with one or more selected from the group consisting of

According to a preferred embodiment of the present invention, the organic layer including the first host and the second host may be a light emitting layer.

The light emitting layer may include a dopant, and the dopant may be a metal complex compound.

The compound represented by the general formula (1) of the present invention is excellent in thermal stability and phosphorescence properties and can be used as a material for an organic material layer of an organic electroluminescent device.

When the compound represented by the formula (1) of the present invention is used as a host material, it is possible to produce an organic electroluminescent device having excellent light emitting performance, low driving voltage, high efficiency and long life time, 1 as a first host and a hole transporting compound having a triplet energy of 2.3 eV or more as a second host can be used to produce a full color display panel with greatly improved performance and lifetime.

Hereinafter, the present invention will be described in detail.

The present invention is characterized in that at least one component of one or more organic layers interposed between an anode and a cathode of an organic electroluminescent device is mixed with a first host and a second host which are different from each other in a specific composition.

Here, the first host is a compound represented by the following formula (1), and the second host may use a hole-transporting compound having a triplet energy of 2.3 eV or more.

In the present invention, triplet energy refers to an electron state in which a spin quantum number is 1 in a molecule, and means energy corresponding to the highest identifiable energy form in the phosphorescence spectrum.

In the present invention, triplet energy refers to an electron state in which a spin quantum number is 1 in a molecule, and refers to an energy corresponding to an identifiable peak energy form in a phosphorescence spectrum.

In the compound of Formula 1 used as the first host in the present invention, a condensed carbon ring or a condensed heterocyclic moiety, preferably a condensed heterocyclic moiety, is connected to the indole-based basic skeleton and the energy level And has a wide band gap (sky blue to red). Therefore, when the compound represented by the general formula (1) is used for an organic material layer of an organic electroluminescent device, phosphorescence characteristics can be improved and electron and / or hole transporting ability and light emitting ability can be enhanced.

Further, since the compound represented by Formula 1 of the present invention exhibits excellent characteristics as a luminescent host material compared to conventional CBP due to its indole-based basic structure, it is more preferably used as a host material of a luminescent layer . Specifically, the compound represented by Formula (1) has a structure in which aromatic rings are substituted with various aromatic rings in the indole-based basic skeleton, and the molecular weight of the compound is significantly increased. As a result, the glass transition temperature is improved, And may have thermal stability. In addition, since the molecules have bipolar characteristics due to various aromatic ring substituents and can increase the bonding force between holes and electrons, they can exhibit excellent characteristics as a host material of a light emitting layer as compared with conventional CBP.

In particular, when the substituent in which the compound represented by Formula 1 is bonded to the indole-based basic skeleton is an N-type material having electron withdrawing characteristics with a high electron absorbing property, a hole transporting compound having a triplet energy of 2.3 eV or more When used as the second host, an organic electroluminescent device having excellent light emitting performance, low driving voltage, high efficiency, and long life can be manufactured. In order to obtain high-efficiency phosphorescence, energy transfer from the host to the dopant is important. The host must have a larger triplet energy than the dopant to prevent the energy transferred to the dopant from reversing to the host, thereby achieving high luminescence efficiency. The role of the host is also important in terms of hole transportability. That is, the second host according to the present invention has a hole transporting property and has a triplet energy of 2.3 eV or more, so carrier transfer to the dopant is easy, and it is easy to confine the energy. In addition, since the material has a band gap equal to or higher than that of the compound of Formula 1 or a LUMO value larger than that of the compound of Formula 1, when the compound of Formula 1 is mixed with the compound of Formula 1 in an appropriate ratio, Can contribute to improvement of various performances, especially life.

≪ First host &

In the organic electroluminescent device according to the present invention, at least one of the one or more organic layers includes the compound represented by Formula 1 as a first host.

In the compound represented by the formula (1) according to the present invention, Y ₁ to Y ₄ are the same or different and each independently N or CR ₃ . Wherein _one of Y ₁ and Y ₂ , Y ₂ and Y ₃ , or Y ₃ and Y ₄ is bonded to a compound represented by the following formula (2) to form a condensed ring.

At this time, it is preferable that all of Y ₁ to Y ₄ which do not form a condensed ring are all CR ₃ , and a plurality of R _{3 s} may be the same or different.

Y ₅ to Y ₈ are the same as or different from each other, and are each independently N or CR ₄ . Here, it is preferable that all of Y ₅ to Y ₈ are CR ₄ , and a plurality of R _{4 s} may be the same or different from each other.

In the compound represented by Formula 1 according to the present invention, X ₁ and X ₂ are each independently O, S, Se, N ( Ar 1), C (Ar 2) (Ar 3) and Si (Ar ₄₎ (Ar ₅ ), wherein at least one of X ₁ and X ₂ may be N (Ar ₁ ).

Considering characteristics of the organic electroluminescent device such as luminous efficiency, driving voltage and lifetime, it is preferable that X ₁ and X ₂ in Formula 1 are independently N (Ar ₁ ) or S, respectively. That is, it is more preferable that X ₁ is N (Ar ₁ ), X ₂ is S, X ₁ is S and X ₂ is N (Ar ₁ ), and X ₁ and X ₂ are all N (Ar ₁ ) Do. Here, each Ar ₁ may be the same or different.

In the compound represented by formula (1) according to the present invention, R ₁ to R ₄ and Ar ₁ to Ar 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 substituted or unsubstituted C ₁ to C ₄₀ alkyl group, a substituted or unsubstituted C ₂ to C ₄₀ alkenyl group, a substituted or unsubstituted C ₂ to C ₄₀ alkynyl group, a substituted or unsubstituted C ₃ ~ C ₄₀ cycloalkyl group, a substituted or unsubstituted nucleus atoms of 3 to 40 heterocycloalkyl group, a substituted or unsubstituted C ₆ ~ C ₆₀ aryl group, a substituted or unsubstituted number of 5 to 60 heteroaryl unsubstituted nucleus atoms aryl group, a substituted or unsubstituted C ₁ ~ C ₄₀ of the alkyloxy group, a substituted or unsubstituted C ₆ ~ C ₆₀ of the aryloxy group, a substituted or unsubstituted C ₁ ~ C ₄₀ alkyl silyl group, a substituted or An unsubstituted C ₆ to C ₆₀ arylsilyl group, a substituted or unsubstituted C ₁ to C ₄₀ alkylboron group, Unsubstituted C ₆ ~ C ₆₀ aryl boron group, a substituted or unsubstituted C ₆ ~ C ₆₀ aryl phosphine group, a substituted or unsubstituted C ₆ ~ C ₆₀ aryl phosphine oxide group, and a substituted or unsubstituted in the ring ring of ring An arylamine group of C ₆ to C ₆₀ , wherein R ₁ to R ₄ may combine with adjacent groups to form a condensed ring,

In R ₁ to R ₄ and Ar ₁ to Ar ₅ , an alkyl group, 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, A halogen atom, a cyano group, a nitro group, an amino group, a C ₁ to C ₄₀ alkyl group, a C ₂ to C ₄₀ alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, C ₄₀ to C ₄₀ alkenyl, C ₂ to C ₄₀ alkynyl, C ₃ to C ₄₀ cycloalkyl, heterocyclic cycloalkyl having 3 to 40 nuclear atoms, C ₆ to C ₄₀ aryl, C ₁ -C ₄₀ alkyloxy, C ₆ -C ₆₀ aryloxy, C ₁ -C ₄₀ alkylsilyl, C ₆ -C ₆₀ arylsilyl, C ₁ -C ₄₀ alkyl, the alkyl boron group, the group consisting of C ₆ ~ C ₆₀ aryl group of boron, C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ C ₆₀ aryl amine of the May be substituted with one or more selected from the group consisting of

In this case, considering the wide band-gap and thermal stability of the compound, R ₁ to R ₄ in the formula (1) are each independently selected from the group consisting of hydrogen, a C ₆ -C ₆₀ aryl group (eg, phenyl, naphthyl, bis Phenyl) or a heteroaryl group having 5 to 60 nuclear atoms (e.g., pyridine, pyrimidine, triazine, quinazoline).

In addition, wherein the Ar ₁ to Ar ₅ are the same or different from each other, and each independently C ₆ ~ C ₆₀ aryl group, the number of nuclear atoms of 5 to 60 heteroaryl group, and a C ₆ ~ or an aryl group consisting of an amine group in the C ₆₀ Is preferably selected.

The compound represented by the formula (1) of the present invention may be further compounded as any one of the compounds represented by the following formulas (3) to (8).

In the above formulas 3 to 8, X ₁ , X ₂ and R ₁ to R ₄ are each as defined in formula (1).

Considering characteristics of the organic electroluminescent device such as luminous efficiency, driving voltage and lifetime, it is preferable that X ₁ and X ₂ in Formula 1 are independently N (Ar ₁ ) or S, respectively. That is, it is preferable that X ₁ is N (Ar ₁ ), X ₂ is S, X ₁ is S, X ₂ is N (Ar ₁ ), or X ₁ and X ₂ are all N (Ar ₁ ).

And R ₁ to R ₄ are the same or different and each independently and independently of one another is hydrogen, a C ₆ to C ₆₀ aryl group (e.g., phenyl, naphthyl, biphenyl) An aryl group (e.g., pyridine, pyrimidine, triazine, quinazoline).

Ar ₁ is the same as or different from each other and is independently selected from the group consisting of C ₆ to C ₆₀ aryl groups, heteroaryl groups having 5 to 60 nuclear atoms, and C ₆ to C ₆₀ arylamine groups desirable.

In the present invention, "alkyl" is a monovalent substituent derived from a linear or branched saturated hydrocarbon having 1 to 40 carbon atoms, and examples thereof include methyl, ethyl, propyl, isobutyl, sec-butyl, pentyl, , Hexyl, and the like.

The "alkenyl" in the present invention is 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 vinyl, allyl allyl, isopropenyl, 2-butenyl, and the like.

"Alkynyl" in the present invention is a monovalent substituent derived from a straight or branched chain unsaturated hydrocarbon having 2 to 40 carbon atoms and having at least one carbon-carbon triple bond. Examples thereof include ethynyl, 2-propynyl, and the like.

In the present invention, "aryl" means a monovalent substituent derived from an aromatic hydrocarbon having 6 to 60 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 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, it is understood that a form in which two or more rings are pendant or condensed with each other may be included, and further includes a condensed form with an aryl group. Examples of such heteroaryls include 6-membered monocyclic rings such as pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, phenoxathienyl, indolizinyl, indolyl indolyl), purinyl, quinolyl, benzothiazole, carbazolyl, 2-furanyl, N-imidazolyl, 2- isoxazolyl , 2-pyridinyl, 2-pyrimidinyl, and the like.

In the present invention, "aryloxy" means a monovalent substituent represented by RO-, and R represents aryl having 5 to 60 carbon atoms. Examples of such aryloxy include phenyloxy, naphthyloxy, diphenyloxy and the like.

The term "alkyloxy" in the present invention means a monovalent substituent group represented by R'O-, wherein R 'represents 1 to 40 alkyl, and may have a linear, branched or cyclic structure . Examples of such alkyloxy include methoxy, ethoxy, n-propoxy, 1-propoxy, t-butoxy, n-butoxy, pentoxy and the like.

"Arylamine" in the present invention means an amine substituted with aryl having 6 to 60 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 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 carbon, preferably 1 to 3 carbons, of the ring is replaced by N, O, S or Se. ≪ / RTI > Examples of such heterocycloalkyl include morpholine, piperazine and the like.

"Alkylsilyl" in the present invention means a 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 compound represented by the formula (1) of the present invention described above can be further formulated into a compound represented by the following illustrated formula, for example, the following formulas (C1) to (C66). However, the compounds represented by formula (1) of the present invention are not limited by the following examples.

In the above formulas C1 to C66, R ₁ to R ₄ are as defined above, and a plurality of R ₃ and R ₄ may be the same or different from each other.

In addition, Ar ₁ to Ar ₅ is preferably as defined above, selected from the group consisting of an aryl amine of the C ₆ ~ C ₆₀ aryl group, the number of nuclear atoms of 5 to 60 heteroaryl group, and a C ₆ ~ C ₆₀ of Do.

In the illustrated formulas, Ar ₁ to Ar ₅ may be the same or different from each other and are each independently selected from the following substituent (functional group) group (S1-S206).

More preferably, at least one of the plurality of Ar < ₁ > is a substituent having a structure including pyridine, pyrimidine, triazine, and quinazoline.

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

<Second Host>

In the organic electroluminescent device according to the present invention, a hole transporting compound having a triplet energy of 2.3 eV or more may be used as the second host used in combination with the first host.

The compound usable as the second host is a compound having a hole transporting property including at least one electron donating group such as a carbazole, an acridine, an arylamine group, a fluorene group and the like. Preferably a compound comprising at least two members selected from the group consisting of an arylamine group, a carbazole group, a fluorene group, and an acridine. When such a second host compound is mixed with the above-mentioned first host in an appropriate ratio, there is an effect of balancing the holes and electrons injected into the device to improve the lifetime.

In the present invention, the mixing ratio of the first host and the second host may be in the range of 1:99 to 99: 1, and preferably the ratio of the first host is high. For example, the ratio of the first host to the second host is 51 to 99: 1 to 49 wt%.

The second host compound according to the present invention is preferably selected from a group of compounds having the following structures. However, the present invention is not limited thereto.

&Lt; Organic electroluminescent device &

Another aspect of the present invention relates to an organic electroluminescent device including the first host and the second host in at least one of the organic material layers.

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 The above-described one host and the second host in a ratio of 1: 99 to 99: 1.

As described above, the first host and the second host are each a compound represented by the following formula (1) and a hole transporting compound having a triplet energy of 2.3 eV or more.

Here, 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 the organic material layer including the first host and the second host is preferably a light emitting layer.

The light emitting layer of the organic electroluminescent device according to the present invention may include a dopant. The dopant may be a metal complex compound including heavy metals such as Ir and Pt, .

The structure of the organic electroluminescent device according to the present invention is not particularly limited and may be a structure in which a substrate, an anode, a hole injecting layer, a hole transporting layer, a light emitting layer, an electron transporting layer, and a cathode are sequentially laminated. At least one of the hole injecting layer, the hole transporting layer, the light emitting layer, the electron transporting layer, and the electron injecting layer may include a compound represented by Formula 1 as a first host and a hole transporting compound having a triplet energy of 2.3 eV or more as a second host can do.

On the other hand, an electron injection layer may be further stacked on the electron transport layer. In addition, the structure of the organic electroluminescent device according to the present invention may be a structure in which an anode, one or more organic layers and an anode are sequentially laminated, and an insulating layer or an adhesive layer is inserted into the interface between the electrode and the organic layer.

The organic electroluminescent device according to the present invention may be formed by using materials and methods known in the art, except that at least one layer (for example, a light emitting layer) of the organic material layer is formed to include the first host and the second host described above Thereby forming another organic material layer and an electrode.

The organic material layer 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 a silicon wafer, quartz, a glass plate, a metal plate, a plastic film and a sheet can be used.

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.

The negative electrode material may be a metal such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin or lead or an alloy thereof; And multi-layer structure materials such as LiF / Al or LiO ₂ / Al, but are not limited thereto.

Meanwhile, since the organic electroluminescent device according to the present invention is driven by a mechanism that emits light by the combination of holes and electrons in the light emitting layer, in order to construct a more efficient and stable light emitting device, And may include all devices manufactured in three ways represented by the following.

The first method is a single host and a light emitting layer composed of dopants used for fine doping.

The luminescent layer will be described in more detail. A luminescent layer is formed by placing a host in a first heat source at a degree of vacuum of 1 × 10 ^-06 torr or less, placing a dopant in a second heat source, -deposition) method. In this case, the mixing ratio of the host material and the dopant material co-deposited may be controlled by the first heat source generated by heating by the heat source, the evaporation rate per second (Å / sec) in the second heat source, The second host) has a mixing ratio of 1 to 30% by weight, preferably 5 to 20% by weight.

In the second method, the first host and the second host are placed in the first heat source and the second heat source, respectively, and the dopant is placed in the third heat source, and heat is simultaneously applied to form a light emitting layer.

The second type of light emitting layer will be described in more detail. A first host having a high electron mobility and a high electron injection efficiency is positioned in a first heat source at a vacuum degree of 1 x 10 ^-06 torr or less , A second host having a high hole mobility and a high hole injection efficiency is disposed in the second heat source to control the dopant and the evaporation rate per second of the third heat source to form a light emitting layer co- . However, the first host and the second host are not limited to only the host including the characteristics described above, and the number of co-deposited hosts may be two or more depending on the characteristics of the light emitting layer. At this time, the dopant is co-deposited with 1 to 30 wt%, and most preferably 5 to 20 wt% with respect to the first host and the second host.

In the third method, the light emitting layer is formed by first mixing the first host and the second host, which are used for forming the light emitting layer, in a proper ratio and physically preliminarily mixing them in one heat source in order to reduce the number of heat sources used and simplify the formation process .

The light emitting layer of the third type will be described in more detail. A host mixed in the first heat source is placed at a degree of vacuum of 1 x 10 ^-06 or less, a dopant is placed in the second heat source, To form a co-deposition system. This method reduces the mixing ratio error occurring when one or more hosts are used, and can form a light emitting layer with a small number of heat sources. Wherein the first host and the second host are physically mixed in a weight ratio of 1: 99 to 99: 1 and are located in the first heat source, wherein the ratio of the dopant to the host (first host + second host) By weight, preferably 5 to 20% by weight, based on the total weight of the light emitting layer.

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 IC-1

<Step 1> Synthesis of 5- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -1H-indole

(25 g, 0.128 mol), 4,4,4 ', 4', 5,5, 5 ', 5'-octamethyl-2,2'-bi (1,3 , 2-dioxaborolane) (48.58 g , 0.191 mol), mixed with _{Pd (dppf) Cl 2 (5.2} g, 5 mol), KOAc (37.55 g, 0.383 mol) and 1,4-dioxane (500 ml) and 130 ℃ Lt; / RTI &gt; for 12 hours. After the reaction was completed, the reaction mixture was extracted with ethyl acetate, the water was removed with MgSO ₄ and purified by column chromatography (Hexane: EA = 10: 1 (v / v)) to obtain 5- (4,4,5,5-tetramethyl -1,3,2-dioxaborolan-2-yl) -1H-indole (22.32 g, yield 72%).

¹ H-NMR:? 1.24 (s, 12H), 6.45 (d, IH), 7.27 (d, IH), 7.42 s, 1 H)

<Step 2> Synthesis of 5- (2-nitrophenyl) -1H-indole

1-bromo-2-nitrobenzene (15.23 g, 75.41 mmol) and 5- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -1H-indole (22 g, 90.49 mmol), NaOH (9.05 g, 226.24 mmol) and THF / H ₂ O, and then, Pd (PPh ₃₎ in 40 ℃ ₄ (4.36 g mixture of (400 ml / 200 ml) , 5 mol%) were added, and the mixture was stirred at 80 ° C for 12 hours.

After completion of the reaction, the reaction mixture was extracted with methylene chloride, and the mixture was added with MgSO ₄ and filtered. The solvent was removed from the obtained organic layer and then purified by column chromatography (Hexane: EA = 3: 1 (v / v)) to obtain 5- (2-nitrophenyl) -1H-indole (11.32 g, yield 63%).

^{1 H-NMR: δ 6.47 (} d, 1H), 7.25 (d, 1H), 7.44 (d, 1H), 7.53 (d, 1H), 7.65 (t, 1H), 7.86 (t, 1H), 7.95 ( (s, 1 H), 8.00 (d, 1 H), 8.09 (t,

<Step 3> Synthesis of 5- (2-nitrophenyl) -1-phenyl-1H-indole

Indole (11 g, 46.17 mmol), iodobenzene (14.13 g, 69.26 mmol), Cu powder (0.29 g, 4.62 mmol), K ₂ mixing the _{CO 3 (6.38 g, 46.17 mmol} ), Na 2 SO 4 (6.56 g, 46.17 mmol), nitrobenzene (200 ml) and stirred at 190 ℃ for 12 hours.

After completion of the reaction, the nitrobenzene was removed. The organic layer was separated with methylene chloride, and water was removed using MgSO ₄ . After removing the solvent from the organic layer from which water had been removed, the residue was purified by column chromatography (Hexane: MC = 3: 1 (v / v)) to obtain 5- (2-nitrophenyl) -1- 71%).

^{1 H-NMR: δ 6.48 (} d, 1H), 7.26 (d, 1H), 7.45 (m, 3H), 7.55 (m, 4H), 7.63 (t, 1H), 7.84 (t, 1H), 7.93 ( s, 1 H), 8.01 (d, 1 H), 8.11 (t, 1 H)

<Step 4> Synthesis of IC-1

Phenyl-1H-indole (5 g, 15.91 mmol), triphenylphosphine (10.43 g, 39.77 mmol) and 1,2-dichlorobenzene (50 ml ) Were mixed and stirred for 12 hours.

After completion of the reaction, 1,2-dichlorobenzene was removed and extracted with dichloromethane. Water was removed from the obtained organic layer with MgSO ₄ and purified by column chromatography (Hexane: MC = 3: 1 (v / v)) to obtain IC-1 (2.38 g, yield 53%).

^{1 H-NMR: δ 6.99 (} d, 1H), 7.12 (t, 1H), 7.27 (t, 1H), 7.32 (d, 1H), 7.41 (t, 1H), 7.50 (d, 1H), 7.60 ( (d, IH), 8.05 (d, IH)

[Preparation Example 2] Synthesis of IC-2

<Step 1> Synthesis of 6- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -1H-indole

The procedure of Step 1 of Preparation Example 1 was repeated except that 6-bromo-1H-indole was used instead of 5-bromo-1H-indole to obtain 6- (4,4,5,5-tetramethyl -1,3,2-dioxaborolan-2-yl) -1H-indole.

¹ H-NMR:? 1.25 (s, 12H), 6.52 (d, IH), 7.16 (d, IH), 7.21 s, 1 H)

<Step 2> Synthesis of 6- (2-nitrophenyl) -1H-indole

Instead of 6- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) -1H-indole, -2-yl) -1H-indole, the procedure of Step 2 of Preparation Example 1 was repeated to obtain 6- (2-nitrophenyl) -1H-indole.

^{1 H-NMR: δ 6.57 (} d, 1H), 7.07 (d, 1H), 7.24 (d, 1H), 7.35 (s, 1H), 7.43 (t, 1H), 7.50 (d, 1H), 7.58 ( t, 1 H), 7.66 (d, 1 H), 7.78 (d,

<Step 3> Synthesis of 6- (2-nitrophenyl) -1-phenyl-1H-indole

The procedure of Step 3 of Preparation Example 1 was repeated except that 6- (2-nitrophenyl) -1H-indole was used instead of 5- (2-nitrophenyl) -1H- -nitrophenyl) -1-phenyl-1H-indole.

^{1 H-NMR: δ 6.81 (} d, 1H), 7.12 (t, 1H), 7.22 (t, 1H), 7.35 (s, 1H), 7.43 (d, 1H), 7.51 (m, 3H), 7.56 ( (m, 2H), 7.62 (m, 2H), 7.85 (d,

<Step 4> Synthesis of IC-2

Step 4 of Preparation Example 1 was repeated except that 6- (2-nitrophenyl) -1-phenyl-1H-indole was used in place of 5- (2-nitrophenyl) And IC-2 was obtained.

^{1 H-NMR: δ 6.80 (} d, 1H), 7.11 (t, 1H), 7.23 (t, 1H), 7.42 (d, 1H), 7.50 (m, 3H), 7.57 (m, 2H), 7.63 ( (m, 2H), 7.86 (d, 1H), 8.03 (d,

[Synthesis Example 1] Synthesis of Com-1

(3 g, 10.63 mmol), 2- (3-chlorophenyl) -4,6-diphenyl-1,3,5-triazine (4.38 g, 12.75 mmol), Pd (OAc) ₂ (2.01 g, 21.25 mmol), P (t-bu) ₃ (0.21 g, 1.06 mmol) and Toluene (100 ml) were mixed and heated at 110 ° C for 12 hours Lt; / RTI &gt;

Extracted with ethyl acetate. After the reaction was terminated, and then remove the water with MgSO ₄ and purified by column chromatography (Hexane: EA = 2: 1 (v / v)) to give the desired compound of Com-1 (4.89 g, yield: 78 to %).

GC-Mass (calculated: 589.23 g / mol, measured: 589 g / mol)

[Synthesis Example 2] Synthesis of Com-2

Except that 2- (3-chlorophenyl) -4,6-diphenylpyrimidine (4.36 g, 12.75 mmol) was used instead of 2- (3-chlorophenyl) -4,6-diphenyl- The same procedure as in Synthesis Example 1 was carried out to obtain Com-2 (4.68 g, yield 75%) as a target compound.

GC-Mass (calculated: 588.23 g / mol, measured: 588 g / mol)

[Synthesis Example 3] Synthesis of Com-3

Except that 2- (3-chlorophenyl) -4,6-diphenylpyridine (4.34 g, 12.75 mmol) was used instead of 2- (3-chlorophenyl) -4,6-diphenyl- The same procedure as in Synthesis Example 1 was carried out to obtain the target compound Com-3 (4.36 g, yield 70%).

GC-Mass (calculated: 587.23 g / mol, measured: 587 g / mol)

[Synthesis Example 4] Synthesis of Com-4

2- (3-chloro-5-methylphenyl) -4,6-diphenyl-1,3,5-triazine instead of 2- (3-chlorophenyl) -4,6-diphenyl- , 12.75 mmol) was used in place of the compound obtained in Synthesis Example 1 to obtain the desired compound Com-4 (4.81 g, yield 75%).

GC-Mass (theory: 603.24 g / mol, measured: 603 g / mol)

[Synthesis Example 5] Synthesis of Com-5

Com-5 (4.81 g, yield 75%) was obtained in the same manner as in Synthesis Example 1, except that IC-2 (3 g, 10.63 mmol) was used instead of IC-1.

GC-Mass (calculated: 589.23 g / mol, measured: 589 g / mol)

[Synthesis Example 6] Synthesis of Com-6

Except that 2-chloro-4,6-diphenyl-1,3,5-triazine (3.40 g, 12.75 mmol) was used instead of 2- (3-chlorophenyl) -4,6-diphenyl-1,3,5- , The target compound, Com-6 (3.98 g, yield 73%) was obtained in the same manner as in Synthesis Example 1. [

GC-Mass (theory: 513.20 g / mol, measured: 513 g / mol)

[Synthesis Example 7] Synthesis of Com-7

Except that 2-chloro-4,6-diphenylpyrimidine (3.40 g, 12.75 mmol) was used instead of 2- (3-chlorophenyl) -4,6-diphenyl-1,3,5- The same procedure was followed to obtain the target compound Com-7 (3.81 g, yield 70%).

GC-Mass (calculated: 512.20 g / mol, measured: 512 g / mol)

[Synthesis Example 8] Synthesis of Com-8

Synthesis Example 1 was repeated except that 2-chloro-4,6-diphenylpyridine (3.38 g, 12.75 mmol) was used instead of 2- (3-chlorophenyl) -4,6-diphenyl- The same procedure was followed to obtain the target compound Com-8 (4.07 g, yield 75%).

GC-Mass (calculated: 511.20 g / mol, measured: 511 g / mol)

[Synthesis Example 9] Synthesis of Com-9

2-chloro-4,6-diphenyl-1,3,5-triazine was used instead of 2- (3-chlorophenyl) -4,6- (3.92 g, yield 72%) was obtained in the same manner as in Synthesis Example 1, except that 1,3,5-triazine (3.38 g, 12.75 mmol) was used.

GC-Mass (theory: 513.20 g / mol, measured: 513 g / mol)

[Examples 1 to 9] Preparation of organic EL device

The glass substrate coated with ITO (Indium tin oxide) thin film with thickness of 1500 Å was washed with distilled water ultrasonic wave. After the distilled water was washed, it was ultrasonically washed with a solvent such as isopropyl alcohol, acetone, or methanol, dried, transferred to a UV OZONE cleaner (Power sonic 405, Hoshin Tech), and then the substrate was cleaned using UV for 5 minutes The substrate was transferred to a vacuum evaporator.

M-MTDATA (60 nm) / TCTA (80 nm) / 10 (nm) was formed on the ITO transparent electrode prepared as described above, using Com-1 synthesized in Synthesis Example 1 as a first host and Mat1 shown below as a second host, (1 nm) / Alq ₃ (30 nm) / LiF (1 nm) / Al (200 nm) were laminated in this order to form an organic EL The device was fabricated.

The structures of m-MTDATA, TCTA, PD-1, BCP, Com-1 and Matl used are as follows.

Organic EL devices were fabricated by adjusting the usage ratios of the first host and the second host as shown in Table 1 below. The driving voltage, current efficiency and emission peak at current densities of 10 mA / cm 2 were measured for the organic EL devices manufactured in Examples 1 to 9, respectively, and the results are shown in Table 1 below.

Sample Host Driving voltage
(V) Current efficiency
(cd / A) Lifetime T ₉₅
(hrs) Example 1 10% Com-1 + 90% Mat1 5.50 42.8 140 Example 2 20% Com-1 + 80% Mat1 5.60 42.6 145 Example 3 30% Com-1 + 70% Mat1 5.50 42.5 140 Example 4 40% Com-1 + 60% Mat1 5.60 43.1 150 Example 5 50% Com-1 + 50% Mat1 5.50 43.2 170 Example 6 60% Com-1 + 40% Mat1 5.35 43.7 180 Example 7 70% Com-1 + 30% Mat1 5.35 45.5 200 Example 8 80% Com-1 + 20% Mat1 5.30 45.0 160 Example 9 90% Com-1 + 10% Mat1 5.35 44.5 155

[ Example  10-18] Organic EL  Device manufacturing

Example 1 M-MTDATA (60 nm) / TCTA (80 nm) / 70% The first host + the second host, using the following Com-1 to Com-9 as the first host and Mat1 as the second host, 30% second host + 10% PD-1 (300 nm) / BCP (10 nm) / Alq ₃ (30 nm) / LiF (1 nm) / Al (200 nm).

The structures of Com-1 to Com-9 used are as follows.

The driving voltage, current efficiency and emission peak at current densities of 10 mA / cm 2 were measured for the organic EL devices manufactured in Examples 10 to 18, respectively, and the results are shown in Table 2 below.

Sample Host Driving voltage
(V) Current efficiency
(cd / A) Lifetime T ₉₅
(hr) Example 10 70% Com-1 + 30% Mat1 5.35 45.5 200 Example 11 70% Com-2 + 30% Mat1 5.50 44.5 180 Example 12 70% Com-3 + 30% Mat1 5.45 42.5 150 Example 13 70% Com-4 + 30% Mat1 5.50 44.2 160 Example 14 70% Com-5 + 30% Mat1 5.60 43.0 150 Example 15 70% Com-6 + 30% Mat1 5.45 42.9 150 Example 16 70% Com-7 + 30% Mat1 5.40 43.1 160 Example 17 70% Com-8 + 30% Mat1 5.50 43.3 160 Example 18 70% Com-9 + 30% Mat1 5.60 43.0 150

[ Comparative Example  1] Organic EL  Device manufacturing

An organic EL device was fabricated in the same manner as in Example 1, except that 100% of the following CBP was used as a host material in forming the light emitting layer in Example 1.

[ Comparative Example  2] Organic EL  Device manufacturing

An organic EL device was fabricated in the same manner as in Example 1 except that 100% Com-1 was used as a host material in forming the light emitting layer in Example 1.

The driving voltage, current efficiency, and emission peak at current densities of 10 mA / cm 2 were measured for the organic EL devices prepared in Comparative Examples 1 and 2, respectively, and the results are shown in Table 3 below.

Sample Host The driving voltage (V) Current efficiency (cd / A) Lifetime T ₉₅ (hr) Comparative Example 1 100% CBP 6.93 38.2 100 Comparative Example 2 100% Com-1 6.55 41.0 120

As shown in Tables 1 to 3, the organic EL devices of Examples 1 to 18 using the compound represented by Formula 1 of the present invention as the first host material of the light emitting layer were prepared by using CBP or Com-1 as a single host material It was confirmed that the organic EL devices of Comparative Examples 1 and 2 exhibited better current efficiency and better driving voltage.

Claims (10)

anode; cathode; And one or more organic layers sandwiched between the anode and the cathode, wherein at least one of the one or more organic layers includes a first host and a second host which are different from each other in a ratio of 1:99 to 99: 1 In addition,
Wherein the first host is a compound represented by the following general formula (1)
Wherein the second host is a hole-transporting compound having a triplet energy of 2.3 eV or more. 2. The organic electroluminescent device according to claim 1,
[Chemical Formula 1]

In Formula 1,
Y ₁ to Y ₄ are the same or different and each independently N or CR ₃ , wherein _one of Y ₁ and Y ₂ , Y ₂ and Y ₃ , or Y ₃ and Y ₄ is represented by the following formula Bonded to the compound to form a condensed ring,
(2)

In Formula 2,
The dotted line represents a site where condensation is carried out with the compound of formula (1)
Y ₅ to Y ₈ are the same or different and are each independently N or CR ₄ ,
X ₁ and X ₂ are the same or different and are each independently selected from the group consisting of O, S, Se, N ( Ar 1), C (Ar 2) (Ar 3) and _{Si (Ar 4) (Ar 5} ) selected, and wherein X ₁ and X _2, at least one is N (Ar ₁₎ in,
R ₁ to R ₄ and Ar ₁ to Ar 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 substituted or unsubstituted C ₁ to C ₄₀ alkyl group , A substituted or unsubstituted C ₂ to C ₄₀ alkenyl group, a substituted or unsubstituted C ₂ to C ₄₀ alkynyl group, a substituted or unsubstituted C ₃ to C ₄₀ cycloalkyl group, a substituted or unsubstituted nuclear atom A substituted or unsubstituted C ₆ to C ₆₀ aryl group, a substituted or unsubstituted heteroaryl group having 5 to 60 ring atoms, a substituted or unsubstituted C ₁ to C ₄₀ aliphatic group, alkyloxy group, a substituted or unsubstituted C ₆ ~ C ₆₀ of the aryloxy group, a substituted or unsubstituted C ₁ ~ C ₄₀ alkyl silyl group, a substituted or unsubstituted C ₆ ~ C ₆₀ aryl silyl group, replacement of the Or an unsubstituted C ₁ to C ₄₀ alkylboron group, a substituted or unsubstituted C ₆ to C ₆₀ arylboron group, a substituted or unsubstituted C ₆ to C _{6 0} of the aryl phosphine is selected from the pingi, a substituted or unsubstituted C ₆ ~ C ₆₀ aryl phosphine oxide group, and the group consisting of a substituted or unsubstituted C ₆ ~ C ₆₀ aryl amine, wherein, R ₁ to R ₄ May bond with adjacent groups to form a condensed ring,
In R ₁ to R ₄ and Ar ₁ to Ar ₅ , an alkyl group, 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, A halogen atom, a cyano group, a nitro group, an amino group, a C ₁ to C ₄₀ alkyl group, a C ₂ to C ₄₀ alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryl group, C ₄₀ to C ₄₀ alkenyl, C ₂ to C ₄₀ alkynyl, C ₃ to C ₄₀ cycloalkyl, heterocyclic cycloalkyl having 3 to 40 nuclear atoms, C ₆ to C ₄₀ aryl, C ₁ -C ₄₀ alkyloxy, C ₆ -C ₆₀ aryloxy, C ₁ -C ₄₀ alkylsilyl, C ₆ -C ₆₀ arylsilyl, C ₁ -C ₄₀ alkyl, the alkyl boron group, the group consisting of C ₆ ~ C ₆₀ aryl group of boron, C ₆ ~ C ₆₀ aryl phosphine group, C ₆ ~ C ₆₀ aryl phosphine oxide group, and a C ₆ ~ C ₆₀ aryl amine of the May be substituted with one or more selected from the group consisting of The organic electroluminescent device according to claim 1, wherein the compound represented by the formula (1) is represented by one of the following formulas (3) to (8).
(3)

[Chemical Formula 4]

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

Wherein X ₁ , X ₂ and R ₁ to R ₄ are as defined in claim 1, respectively. The organic electroluminescent device according to claim 1, wherein X ₁ and X ₂ are all N (Ar ₁ ), wherein each Ar ₁ is the same or different. The compound according to claim 1, wherein Y ₁ to Y _{4 which} are not condensed with the above-mentioned formula (2) are all CR ₃ , Y ₅ to Y ₈ are all CR ₄ ,
Wherein each of R &lt; ₃ &gt; and R &lt; ₄ &gt; is the same or different from each other. The compound according to Claim 1, wherein Ar ₁ to Ar ₅ are the same or different and each independently represents a C ₆ to C ₆₀ aryl group, a heteroaryl group having 5 to 60 nuclear atoms and a C ₆ to C ₆₀ arylamine &Lt; / RTI &gt;
A C ₆ ~ C ₆₀ aryl group, the number of nuclear atoms of 5 to 60 heteroaryl group, and a C ₆ ~ C ₆₀ aryl amine groups are each C alkyl group of ₁ ~ C _40, C ₆ ~ C ₆₀ aryl group, the nucleus of atoms of And a heteroaryl group having a number of 5 to 60, or is unsubstituted or substituted with at least one functional group selected from the group consisting of a heteroaryl group having a number of 5 to 60. The compound according to claim 1, wherein R ₁ to R ₄ are the same or different and each independently selected from the group consisting of hydrogen, a C ₆ to C ₆₀ aryl group, and a heteroaryl group having 5 to 60 nuclear atoms,
The C ₆ to C ₆₀ aryl group and the heteroaryl group having 5 to 60 nuclear atoms are each a group consisting of a C ₁ to C ₄₀ alkyl group, a C ₆ to C ₆₀ aryl group, and a heteroaryl group having 5 to 60 nuclear atoms &Lt; / RTI &gt; is substituted or unsubstituted with at least one functional group selected from &lt; RTI ID = 0.0 &gt; The organic electroluminescent device according to claim 1, wherein the compound used as the second host comprises at least two members selected from the group consisting of an arylamine group, a carbazole group, a fluorene group, and an acridine. . The organic electroluminescent device according to claim 1, wherein the compound used as the second host is selected from the group consisting of compounds having the following structures.

The organic electroluminescent device according to claim 1, wherein the organic material layer including the first host and the second host is a light emitting layer. The organic electroluminescent device according to claim 9, wherein the light emitting layer comprises a dopant, and the dopant is a metal complex compound.