TECHNICAL FIELD

The present disclosure relates to a novel compound and an organic electroluminescent device including the same, and more particularly, to a novel compound having excellent hole injection capabilities, hole transport capabilities, light-emitting capabilities, and the like, and an organic electroluminescent device which contains the compound as a material for an organic material layer so as to improve characteristics such as light-emitting efficiency, driving voltage, and a service life.

BACKGROUND ART

A study on an organic electroluminescent (EL) device (hereinafter, simply referred to as ‘organic EL device’) has continued from the start point of observing an organic thin film light emission by Bernanose in the 1950s to blue electric light emission using an anthracene single crystal in 1965, and an organic EL device having a lamination structure, which is divided into functional layers of a hole layer and a light-emitting layer, was proposed by Tang in 1987. Thereafter, the organic EL device has been developed in the form of introducing a characteristic organic material layer into a device in order to enhance efficiency and a service life of the organic EL device, and the development has also been led to the development of specialized materials used therein.

In the organic electroluminescent device, when voltage is applied between two electrodes, holes are injected into the organic material layer at the anode and electrons are injected into the organic material layer at the cathode. When the injected holes and electrons meet each other, an exciton is formed, and when the exciton falls down to a bottom state, light is emitted. Materials used as the organic material layer may be classified into a light-emitting material, a hole injection material, a hole transporting material, an electron transporting material, an electron injection material, and the like according to the function.



Meanwhile, in order to achieve practical application of the organic electroluminescent device and enhance characteristics thereof, the device needs to be formed of an organic material layer having the multi-layered structure as described above, and a material for the device, particularly a hole transporting material, needs to have thermally and electrically stable characteristics. This is because when voltage is applied to an organic electroluminescent device, heat is generated from the device, and molecules having low thermal stability are rearranged due to low crystal stability, and as a result, there occurs a local crystallization, and thus there exists an inhomogeneous portion, and an electric field is concentrated on the inhomogeneous portion, thereby degrading and destroying the device.

In consideration of these points, m-MTDATA [4,4′,4″-tris(N-3-methylphenyl-N-phenylamino)-triphenylamine], 2-TNATA [4,4′,4″-tris (N-(naphthylen-2-yl)-N-phenylamino)-triphenylamine], TPD [N,N′-diphenyl-N,N′-di(3-methylphenyl)-4,4′-diaminobiphenyl] and NPB [N,N′-di(naphthalene-1-yl)-N,N′-diphenylbenzidine], and the like were used in the related art as a hole transporting material.

However, since m-MTDATA and 2-TNATA have a low glass transition temperature (Tg) of about 78° C. and about 108° C., respectively, and many problems occur in the process of mass production, there has been a problem in implementing a full color. Meanwhile, TPD and NPB also have a low glass transition temperature (Tg) of about 60° C. and about 96° C., respectively, thereby causing deterioration in the service life of the device like m-MTDATA and 2-TNATA.

Therefore, there is a need for the development of a new hole transporting material which may increase thermal stability and has excellent hole transport capabilities, and thus may enhance the light-emitting efficiency and power efficiency of the organic electroluminescent device.

DISCLOSURE

Technical Problem

An object of the present disclosure is to provide a novel compound which has excellent hole injection capabilities, hole transport capabilities, light-emitting capabilities, and the like, and thus may be used as a material for a light-emitting layer, a material for a hole transporting layer, and a material for a hole injection layer.

Further, another object of the present disclosure is to provide an organic electroluminescent device which includes the novel compound, and thus has low driving voltage, high light-emitting efficiency, and enhanced service life.

Technical Solution

In order to achieve the objects, the present disclosure provides a compound represented by the following Formula 1.



In Formula 1,

Y1to Y4are each independently N or CR3, and in this case, when CR3is present in a plural number, they are the same as or different from each other, and

provided that at least one of Y1and Y2, Y2and Y3, and Y3and Y4is CR3, and forms a fused ring represented by the following Formula 2;



in Formula 2,

Y5to Y8are each independently selected from N or CR4, and in this case, when CR4is present in a plural number, they are the same as or different from each other, and

provided that at least one of Y5to Y8is CR4, and in this case, at least one R4is a substituent represented by the following Formula 3;



in Formula 3,

L is a single bond, or selected from the group consisting of a substituted or unsubstituted C6to C60arylene group, and a substituted or unsubstituted heteroarylene group having 5 to 60 nuclear atoms,

in this case, one or more substituents each introduced into the arylene group and the heteroarylene group of L are each independently selected from the group consisting of deuterium, halogen, cyano, a C1to C40alkyl group, a C3to C40cycloalkyl group, a heterocycloalkyl group having 3 to 40 nuclear atoms, a C6to C60aryl group, a heteroaryl group having 5 to 60 nuclear atoms, a C1to C40alkyloxy group, a C6to C60aryloxy group, and a C6to C60arylamine group, and provided that when the substituent is present in a plural number, these may be the same as or different from each other;

Raand Rbare each independently selected from the group consisting of a substituted or unsubstituted C1to C40alkyl group, a substituted or unsubstituted C3to C40cycloalkyl group, a substituted or unsubstituted heterocycloalkyl group having 3 to 40 nuclear atoms, a substituted or unsubstituted C6to C60aryl group, and a substituted or unsubstituted heteroaryl group having 5 to 60 nuclear atoms,

in this case, one or more substituents each introduced into the alkyl group, the cycloalkyl group, the heterocycloalkyl group, the aryl group, and the heteroaryl group of Raand Rbare each independently selected from the group consisting of deuterium, halogen, cyano, a C1to C40alkyl group, a C3to C40cycloalkyl group, a heterocycloalkyl group having 3 to 40 nuclear atoms, a C6to C60aryl group, a heteroaryl group having 5 to 60 nuclear atoms, a C1to C40alkyloxy group, a C6to C60aryloxy group, a C1to C40alkylsilyl group, a C6to C60arylsilyl group, a C1to C40alkyl boron group, a C6to C60aryl boron group, a C6to C60arylphosphine group, a C6to C60arylphosphine oxide group, and a C6to C60arylamine group, and provided that when the substituent is present in a plural number, these may be the same as or different from each other;

provided that L, Ra, and Rbmay combine with an adjacent substituent to form a fused ring;

X1and X2are each independently selected from the group consisting of O, S, Se, N(Ar1), C(Ar2)(Ar3), and Si(Ar4)(Ar5), and in this case, when N(Ar1) is present in a plural number, they are the same as or different from each other, when C(Ar2)(Ar3) is present in a plural number, they are the same as or different from each other, and when Si(Ar4)(Ar5) is present in a plural number, they are the same as or different from each other, and

provided that at least one of X1and X2is N(Ar1);

Ar1to Ar5are the same as or different from each other, and are each independently selected from the group consisting of a substituted or unsubstituted C1to C40alkyl group, a substituted or unsubstituted C3to C40cycloalkyl group, a substituted or unsubstituted heterocycloalkyl group having 3 to 40 nuclear atoms, a substituted or unsubstituted C6to C60aryl group, a substituted or unsubstituted heteroaryl group having 5 to 60 nuclear atoms, a substituted or unsubstituted C1to C40alkyloxy group, a substituted or unsubstituted C6to C60aryloxy group, a substituted or unsubstituted C1to C40alkylsilyl group, a substituted or unsubstituted C6to C60arylsilyl group, a substituted or unsubstituted C1to C40alkyl boron group, a substituted or unsubstituted C6to C60aryl boron group, a substituted or unsubstituted C6to C60arylphosphine group, a substituted or unsubstituted C6to C60arylphosphine oxide group, or a substituted or unsubstituted C6to C60arylamine group;

R1to R4are each independently selected from the group consisting of hydrogen, deuterium, halogen, cyano, a substituted or unsubstituted C1to C40alkyl group, a substituted or unsubstituted C3to C40cycloalkyl group, a substituted or unsubstituted heterocycloalkyl group having 3 to 40 nuclear atoms, a substituted or unsubstituted C6to C60aryl group, a substituted or unsubstituted heteroaryl group having 5 to 60 nuclear atoms, a substituted or unsubstituted C1to C40alkyloxy group, a substituted or unsubstituted C6to C60aryloxy group, a substituted or unsubstituted C1to C40alkylsilyl group, a substituted or unsubstituted C6to C60arylsilyl group, a substituted or unsubstituted C1to C40alkyl boron group, a substituted or unsubstituted C6to C60aryl boron group, a substituted or unsubstituted C6to C60arylphosphine group, a substituted or unsubstituted C6to C60arylphosphine oxide group, and a substituted or unsubstituted C6to C60arylamine group, and these form or do not form a fused ring with an adjacent group; and

one or more substituents each introduced into the alkyl group, the cycloalkyl group, the heterocycloalkyl group, the aryl group, the heteroaryl group, the alkyloxy group, the aryloxy group, and the arylamine group of R1to R4and Ar1to Ar5are each independently selected from the group consisting of deuterium, halogen, cyano, a C1to C40alkyl group, a C3to C40cycloalkyl group, a heterocycloalkyl group having 3 to 40 nuclear atoms, a C6to C60aryl group, a heteroaryl group having 5 to 60 nuclear atoms, a C1to C40alkyloxy group, a C6to C60aryloxy group, a substituted or unsubstituted C1to C40alkylsilyl group, a C6to C60arylsilyl group, a C1to C40alkyl boron group, a C6to C60aryl boron group, a C6to C60arylphosphine group, a C6to C60arylphosphine oxide group, and a C6to C60arylamine group, and provided that when the substituent is present in a plural number, these may be the same as or different from each other.

Further, the present disclosure provides an organic electroluminescent device including an anode, a cathode, and an organic material layer including one or more layers interposed between the anode and the cathode, in which at least one of the organic material layers including one or more layers includes the compound.

The organic material layer including one or more layers, which includes the compound, is selected from the group consisting of a hole transporting layer, a hole injection layer, and a light-emitting layer, and is preferably a hole transporting layer and/or a light-emitting layer, and is more preferably used as a material for a hole transporting layer.

Advantageous Effects

The compound according to the present disclosure has excellent heat resistance, hole injection capabilities, hole transport capabilities, light-emitting capabilities, and the like, and thus may be used as a material for an organic material layer of an organic electroluminescent device, preferably a material for a hole injection layer, a material for a hole transporting layer, or a material for a light-emitting layer.

In addition, an organic EL device including the compound according to the present disclosure in a hole injection layer, a hole transporting layer and/or a light-emitting layer may be enhanced greatly in terms of light-emitting performance, driving voltage, a service life, efficiency, and the like, and furthermore, the device may be effectively applied to a full-color display panel, and the like.

