KR20230028739A - Multi-Component Host Material and an Organic Electroluminescence Device Comprising the Same - Google Patents

Abstract

The present invention relates to a host material of multiple types and an organic electroluminescent element comprising the same. The organic electroluminescent element of the present invention, by comprising a host compound of multiple types of specific combinations, can exhibit a high light-emitting efficiency and an excellent lifespan characteristic.

Description

Multi-Component Host Material and an Organic Electroluminescence Device Comprising the Same}

The present invention relates to a plurality of host materials and an organic electroluminescent device including the same.

An electroluminescence device (EL device) is a self-luminous display device and has advantages of a wide viewing angle, excellent contrast, and fast response speed. In 1987, Eastman Kodak Co., Ltd. first developed an organic electroluminescent device using a low-molecular aromatic diamine and an aluminum complex as a material for forming a light emitting layer [Appl. Phys. Lett. 51, 913, 1987].

An organic electroluminescence device (OLED) is a device that converts electrical energy into light by applying electricity to an organic light emitting material, and has a structure that usually includes an anode and a cathode and an organic material layer therebetween. The organic material layer of the organic electroluminescent device may include a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer (including a host and a dopant material), an electron buffer layer, a hole blocking layer, an electron transport layer, an electron injection layer, and the like. The materials used for are divided into hole injection materials, hole transport materials, electron blocking materials, light emitting materials, electron buffer materials, hole blocking materials, electron transport materials, and electron injection materials according to their functions. In such an organic electroluminescent device, holes are injected from an anode and electrons from a cathode are injected into the light emitting layer by application of a voltage, and excitons with high energy are formed by recombination of holes and electrons. The light emitting organic compound is brought into an excited state by this energy, and as the excited state of the light emitting organic compound returns to a ground state, energy is emitted as light and light is emitted.

The light emitting material of the organic electroluminescent device is the most important factor determining the light emitting efficiency of the device. The light emitting material must have high quantum efficiency and high mobility of electrons and holes, and the formed light emitting material layer must be uniform and stable. These light emitting materials are classified into blue, green or red light emitting materials according to the light emitting color, and there are also yellow or orange light emitting materials. In addition, the light emitting material may be classified into a host material and a dopant material in terms of functionality. Recently, the development of high-efficiency and long-life organic electroluminescent devices has emerged as an urgent task. In particular, considering the level of EL characteristics required by medium and large-sized OLED panels, it is urgent to develop materials that are superior to conventional light-emitting materials. . To this end, desirable properties of the host material serving as a solvent and energy carrier in a solid state should be high in purity and have an appropriate molecular weight to enable vacuum deposition. In addition, thermal stability must be secured due to high glass transition temperature and thermal decomposition temperature, high electrochemical stability is required for long lifespan, and it must be easy to form an amorphous thin film. Shouldn't.

The light emitting material may be used by mixing a host and a dopant to improve color purity, luminous efficiency and stability. In general, a device having excellent EL characteristics has a structure including a light emitting layer made by doping a host with a dopant. When using such a dopant/host material system, the selection of the host material is important because it greatly affects the efficiency and lifetime of the light emitting device.

Korean Patent Publication No. 10-2008-0080306 discloses an organic electroluminescent device using a compound in which two carbazoles are linked through arylene as a host material, and International Publication WO 2013/112557 A1 discloses that biscarbazole is aryl Disclosed is an organic electroluminescent device using a compound linked to carbazole with Ren as a linker as a host material. However, the above references show that compounds in which biscarbazole containing aryl is directly or through arylene are linked to dibenzothiophene or dibenzofuran and compounds in which carbazole is directly or through arylene are linked to heteroaryl are used as a plurality of hosts. The organic electroluminescent device used as is not specifically disclosed.

Korean Patent Publication No. 10-2008-0080306 (published on September 3, 2008) International Publication WO 2013/112557 A1 (published on August 1, 2013)

An object of the present invention is to provide an organic electroluminescent device having improved lifetime characteristics.

As a result of intensive research to solve the above technical problem, the present inventors have at least one light emitting layer between an anode and a cathode, the light emitting layer includes a host and a phosphorescent dopant, and the host is composed of a plurality of host compounds. and wherein, among the plurality of host compounds, at least a first host compound is represented by Formula 1, and a second host compound is represented by Formula 2; completed the present invention.

In Formulas 1 and 2,

Ar ₁ is a substituted or unsubstituted (C6-C30)aryl;

L ₁ and L ₂ are each independently a single bond or a substituted or unsubstituted (C6-C30)arylene;

X is O or S;

R ₁ to R ₃₂ are each independently hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30)alkyl, substituted or unsubstituted (C2-C30)alkenyl, substituted or unsubstituted (C2 -C30) alkynyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (C6-C60) aryl, substituted or unsubstituted (3-30 membered) heteroaryl, substituted or unsubstituted Tri(C1-C30)alkylsilyl, substituted or unsubstituted tri(C6-C30)arylsilyl, substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, or substituted or unsubstituted mono - or di- (C6-C30) arylamino; Adjacent substituents may be connected to each other to form a substituted or unsubstituted (C3-C30) monocyclic or polycyclic alicyclic or aromatic ring, and the carbon atoms of the formed alicyclic or aromatic ring are selected from nitrogen, oxygen and sulfur. can be replaced with one or more heteroatoms that are;

Ar ₂ is a substituted or unsubstituted (3-30 membered) heteroaryl;

The heteroaryl includes one or more heteroatoms selected from B, N, O, S, Si and P.

According to the present invention, an organic electroluminescent device having high efficiency and long lifespan is provided, and a display device or lighting device using the same can be manufactured.

Although the present invention is described in more detail below, it is for illustrative purposes only and should not be construed in any way to limit the scope of the present invention.

The organic electroluminescent device including the organic electroluminescent compound represented by Chemical Formulas 1 and 2 will be described in detail as follows.

The compound of Formula 1 may be represented by Formula 3, 4, 5 or 6 below.

In Formulas 3 to 6,

Ar ₁ , L ₁ , X and R ₁ to R ₂₄ are as defined in Formula 1.

In Formula 1, L ₁ is a single bond or a substituted or unsubstituted (C6-C30)arylene, preferably a single bond or a substituted or unsubstituted (C6-C15)arylene, and a single bond or unsubstituted It is more preferably (C6-C15) arylene.

In Formula 1, X is O or S.

In Formula 1, Ar ₁ is a substituted or unsubstituted (C6-C30)aryl, preferably a substituted or unsubstituted (C6-C20)aryl, and a substituted or unsubstituted (C6-C20)aryl ( more preferably C6-C20) aryl.

In Formula 1, R ₁ to R ₂₄ are each independently hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30)alkyl, substituted or unsubstituted (C2-C30)alkenyl, substituted or Unsubstituted (C2-C30) alkynyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (C6-C60) aryl, substituted or unsubstituted (3-30 membered) heteroaryl, Substituted or unsubstituted tri(C1-C30)alkylsilyl, substituted or unsubstituted tri(C6-C30)arylsilyl, substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, or substituted or unsubstituted mono- or di-(C6-C30)arylamino; Adjacent substituents may be connected to each other to form a substituted or unsubstituted (C3-C30) monocyclic or polycyclic alicyclic or aromatic ring, and the carbon atoms of the formed alicyclic or aromatic ring are selected from nitrogen, oxygen and sulfur. may be replaced with one or more heteroatoms that are, preferably each independently hydrogen.

In Formula 2, L ₂ is a single bond or a substituted or unsubstituted (C6-C30)arylene, preferably a single bond or a substituted or unsubstituted (C6-C15)arylene, and a single bond or a tri( It is more preferably (C6-C15) arylene unsubstituted or substituted with C6-C15) arylsilyl.

In Formula 2, Ar ₂ is a substituted or unsubstituted (3-30 membered) heteroaryl, preferably a substituted or unsubstituted nitrogen-containing (5-11 membered) heteroaryl, and an unsubstituted (C6-C18 ) Aryl, (C6-C12)aryl substituted with cyano, (C6-C12)aryl substituted with (C1-C6)alkyl, (C6-C12)aryl substituted with tri(C6-C12)arylsilyl, or ( It is more preferably a nitrogen-containing (6-10 membered) heteroaryl substituted with a 6-15 membered) heteroaryl.

In addition, Ar ₂ is a single ring heteroaryl such as pyrrolyl, imidazolyl, pyrazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, or benzoimine. such as dazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, naphthyridinyl, quinoxalinyl, carbazolyl, or phenanthridinyl. It may be a fused-ring heteroaryl, preferably triazinyl, pyrimidinyl, quinolyl, isoquinolyl, quinazolinyl, naphthyridinyl, or quinoxalinyl.

In Formula 2, R ₂₅ to R ₃₂ are each independently hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30)alkyl, substituted or unsubstituted (C2-C30)alkenyl, substituted or Unsubstituted (C2-C30) alkynyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (C6-C60) aryl, substituted or unsubstituted (3-30 membered) heteroaryl, Substituted or unsubstituted tri(C1-C30)alkylsilyl, substituted or unsubstituted tri(C6-C30)arylsilyl, substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, or substituted or unsubstituted mono- or di-(C6-C30)arylamino; Adjacent substituents may be connected to each other to form a substituted or unsubstituted (C3-C30) monocyclic or polycyclic alicyclic or aromatic ring, and the carbon atoms of the formed alicyclic or aromatic ring are selected from nitrogen, oxygen and sulfur. may be replaced with one or more heteroatoms that are, each independently hydrogen, cyano, substituted or unsubstituted (C6-C15) aryl, substituted or unsubstituted (10-20 membered) heteroaryl, or substituted or unsubstituted tri(C6-C10)arylsilyl; Adjacent substituents are preferably connected to each other to form a substituted or unsubstituted (C6-C20) monocyclic or polycyclic aromatic ring, and each independently substituted or unsubstituted with hydrogen, cyano, tri(C6-C10) arylsilyl substituted or unsubstituted (10-20 membered) heteroaryl with cyclic (C6-C15)aryl, (C6-C12)aryl, or unsubstituted tri(C6-C10)arylsilyl; Adjacent substituents are connected to each other to form substituted or unsubstituted benzene, substituted or unsubstituted indole, substituted or unsubstituted benzoindole, substituted or unsubstituted indene, substituted or unsubstituted benzofuran, or substituted or unsubstituted benzo It is more preferred to form a thiophene.

In addition, L ₁ and L ₂ may each independently be represented by one of Formulas 7 to 19 below.

In Formulas 7 to 19,

Xi to Xp are each independently hydrogen, deuterium, halogen, cyano, substituted or unsubstituted (C1-C30)alkyl, substituted or unsubstituted (C2-C30)alkenyl, substituted or unsubstituted (C2-C30 ) Alkynyl, substituted or unsubstituted (C3-C30) cycloalkyl, substituted or unsubstituted (C6-C60) aryl, substituted or unsubstituted (3-30 membered) heteroaryl, substituted or unsubstituted tri( C1-C30)alkylsilyl, substituted or unsubstituted tri(C6-C30)arylsilyl, substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, or substituted or unsubstituted mono- or di- (C6-C30) arylamino; Adjacent substituents may be connected to each other to form a substituted or unsubstituted (C3-C30) monocyclic or polycyclic alicyclic or aromatic ring, and the carbon atoms of the formed alicyclic or aromatic ring are separated from nitrogen, oxygen, and sulfur. may be replaced with one or more selected heteroatoms.

As used herein, “(C1-C30)alkyl” means a straight-chain or branched-chain alkyl having 1 to 30 carbon atoms, preferably 1 to 20 carbon atoms, and more preferably 1 to 10 carbon atoms. . Specific examples of the alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl. As used herein, "(C2-C30)alkenyl" means a straight or branched chain alkenyl having 2 to 30 carbon atoms, preferably 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms. Specific examples of the alkenyl include vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methylbut-2-enyl, and the like. As used herein, "(C2-C30)alkynyl" means a straight or branched chain alkynyl having 2 to 30 carbon atoms, preferably 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms. Examples of the alkynyl include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, and 1-methylpent-2-ynyl. As used herein, "(C3-C30)cycloalkyl" means a monocyclic or polycyclic hydrocarbon having 3 to 30 carbon atoms, preferably 3 to 20 carbon atoms, more preferably 3 to 7 carbon atoms. Examples of the cycloalkyl include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like. As used herein, "(3-7 membered) heterocycloalkyl" has 3 to 7 ring skeleton atoms, preferably 5 to 7 atoms, and at least one hetero group selected from the group consisting of B, N, O, S, Si and P. It means a cycloalkyl containing one or more heteroatoms selected from atoms, preferably O, S and N, and examples thereof include tetrahydrofuran, pyrrolidine, thiolane, tetrahydropyran and the like. As used herein, "(C6-C30)aryl(ene)" means a monocyclic or fused ring radical derived from an aromatic hydrocarbon having 6 to 30 carbon atoms, wherein a ring skeleton having 6 to 20 carbon atoms is preferable, and 6 It is more preferable that it is 15 to 15. Examples of the aryl include phenyl, biphenyl, terphenyl, naphthyl, binapthyl, phenylnaphthyl, naphthylphenyl, fluorenyl, phenylfluorenyl, benzofluorenyl, dibenzofluorenyl, and phenane. trenyl, phenylphenanthrenyl, anthracenyl, indenyl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, chrysenyl, naphthacenyl, fluoranthenyl, and the like. As used herein, "(3-30 membered) heteroaryl" means an aryl group having 3 to 30 ring skeleton atoms and containing one or more heteroatoms selected from the group consisting of B, N, O, S, Si and P. The number of hetero atoms is preferably 1 to 4, and may be a single ring system or a fused ring system condensed with one or more benzene rings, and may be partially saturated. In addition, the heteroaryl herein includes a form in which one or more heteroaryl groups or aryl groups are connected to a heteroaryl group by a single bond. Examples of the heteroaryl include furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl , triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, single ring heteroaryl such as pyridazinyl, benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, di Benzothiophenyl, benzoimidazolyl, benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl, benzooxazolyl, isoindolyl, indolyl, benzoindolyl, indazolyl, benzothiadiazolyl, quinolyl, iso and fused ring heteroaryls such as quinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, carbazolyl, phenoxazinyl, phenanthridinyl, and benzodioxolyl. As used herein, "nitrogen-containing (5-30 membered) heteroaryl" means an aryl group having 5 to 30 ring skeleton atoms and containing at least one heteroatom N. Here, the number of ring skeleton atoms is preferably 5 to 20, and more preferably 5 to 15. The number of heteroatoms is preferably 1 to 4, and it may be a single ring system or a fused ring system condensed with one or more benzene rings, and may be partially saturated. In addition, the nitrogen-containing heteroaryl herein includes a form in which one or more heteroaryl groups or aryl groups are connected to a heteroaryl group by a single bond. Examples of the nitrogen-containing heteroaryl include single-ring heteroaryls such as pyrrolyl, imidazolyl, pyrazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, pyridyl, pyrazinyl, pyrimidinyl, and pyridazinyl. , benzoimidazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, carbazolyl, fused ring system such as phenanthridinyl heteroaryl, etc. As used herein, “halogen” includes F, Cl, Br and I atoms.

In addition, "substitution" in the description of "substituted or unsubstituted" described in the present invention means that a hydrogen atom in a certain functional group is replaced with another atom or other functional group (ie, a substituent). Substituted alkyl, substituted alkenyl, substituted alkynyl, substituted cycloalkyl, substituted aryl(ene), substituted heteroaryl in Ar ₁ , Ar ₂ , L ₁ , L ₂ , and R ₁ to R ₃₂ of Formulas 1 and 2 above , Substituents of substituted trialkylsilyl, substituted triarylsilyl, substituted dialkylarylsilyl, substituted mono- or di-arylamino, and substituted monocyclic or polycyclic alicyclic or aromatic rings are each independently deuterium, halogen, cyano , carboxyl, nitro, hydroxy, (C1-C30)alkyl, halo(C1-C30)alkyl, (C2-C30)alkenyl, (C2-C30)alkynyl, (C1-C30)alkoxy, (C1- C30) alkylthio, (C3-C30) cycloalkyl, (C3-C30) cycloalkenyl, (3-7 membered) heterocycloalkyl, (C6-C30) aryloxy, (C6-C30) arylthio, (C6 -C30) unsubstituted or substituted with aryl (3-30 membered) heteroaryl, cyano, (3-30 membered) heteroaryl or tri(C6-C30) arylsilyl substituted or unsubstituted (C6-C30) Aryl, tri(C1-C30)alkylsilyl, tri(C6-C30)arylsilyl, di(C1-C30)alkyl(C6-C30)arylsilyl, (C1-C30)alkyldi(C6-C30)arylsilyl, Amino, mono- or di- (C1-C30) alkylamino, mono- or di- (C6-C30) arylamino, (C1-C30) alkyl (C6-C30) arylamino, (C1-C30) alkylcarbonyl , (C1-C30) alkoxycarbonyl, (C6-C30) arylcarbonyl, di (C6-C30) arylboronyl, di (C1-C30) alkylboronyl, (C1-C30) alkyl (C6- C30) arylboronyl, (C6-C30) ar (C1-C30) alkyl and (C1-C30) alkyl (C6-C30) means one or more selected from the group consisting of aryl, each independently cyano , (C1-C6) alkyl, (5-15 membered) heteroaryl, (C6-C18) aryl, (C6-C18) aryl substituted with cyano, (C6-C18) substituted with tri(C6-C12) arylsilyl ) At least one selected from the group consisting of aryl, tri(C6-C12)arylsilyl and (C1-C6)alkyl(C6-C18)aryl It is preferable to be

Triarylsilyl in Formulas 1 and 2 is preferably triphenylsilyl.

The first host compound represented by Chemical Formula 1 may be exemplified as the following compounds, but is not limited thereto.

The second host compound represented by Chemical Formula 2 may be exemplified as the following compounds, but is not limited thereto.

An organic electroluminescent device according to the present invention includes an anode; cathode; and one or more organic material layers interposed between the anode and the cathode, wherein the organic material layer includes a light emitting layer, the light emitting layer includes a host and a phosphorescent dopant, the host is composed of a plurality of host compounds, and the plurality of Among the host compounds of the species, at least a first host compound is represented by Formula 1 above, and a second host compound is represented by Formula 2 above.

The meaning of the light emitting layer is a layer in which light is emitted, and may be a single layer, or may be a plurality of layers in which two or more layers are stacked. It is preferable that the doping concentration of the dopant compound with respect to the host compound of the light emitting layer is less than 20% by weight.

The organic material layer includes a light emitting layer, and may further include one or more layers selected from a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, an interlayer, a hole blocking layer, and an electron blocking layer.

In the organic electroluminescent device of the present invention, the weight ratio of the first host compound to the second host compound ranges from 1:99 to 99:1.

As the dopant included in the organic electroluminescent device of the present invention, at least one phosphorescent dopant is preferable. The phosphorescent dopant material applied to the organic electroluminescent device of the present invention is not particularly limited, but a complex compound of metal atoms selected from iridium (Ir), osmium (Os), copper (Cu) and platinum (Pt) is preferred. And, an ortho-metallized complex compound of a metal atom selected from iridium (Ir), osmium (Os), copper (Cu), and platinum (Pt) is more preferable, and an ortho-metallated iridium complex compound is still more preferable.

The phosphorescent dopant is preferably selected from the group consisting of compounds represented by Chemical Formulas 101 to 103 below.

In Chemical Formulas 101 to 103,

L is selected from the following structures;

R ₁₀₀ is hydrogen, substituted or unsubstituted (C1-C30)alkyl, or substituted or unsubstituted (C3-C30)cycloalkyl;

R ₁₀₁ to R ₁₀₉ and R ₁₁₁ to R ₁₂₃ are each independently hydrogen, deuterium, halogen, deuterium or halogen-substituted or unsubstituted (C1-C30)alkyl, substituted or unsubstituted (C3-C30)cycloalkyl, substituted or unsubstituted (C6-C30)aryl, cyano, or substituted or unsubstituted (C1-C30)alkoxy; R ₁₀₆ to R ₁₀₉ are substituted or unsubstituted (3-30 membered) monocyclic or polycyclic alicyclic or (hetero)aromatic rings (eg, substituted or unsubstituted fluorene with alkyl, alkyl substituted or unsubstituted dibenzothiophene, alkyl substituted or unsubstituted dibenzofuran); R ₁₂₀ to R ₁₂₃ are substituted or unsubstituted (3-30 membered) monocyclic or polycyclic alicyclic or (hetero)aromatic rings (eg, halogen, alkyl or aryl substituted or unsubstituted) in which adjacent substituents are connected to each other; quinoline);

R ₁₂₄ to R ₁₂₇ are each independently hydrogen, deuterium, halogen, substituted or unsubstituted (C1-C30)alkyl, or substituted or unsubstituted (C6-C30)aryl;

R ₁₂₄ to R ₁₂₇ are substituted or unsubstituted (3-30 membered) monocyclic or polycyclic alicyclic or (hetero)aromatic rings (eg, substituted or unsubstituted fluorene with alkyl, alkyl substituted or unsubstituted dibenzothiophene, alkyl substituted or unsubstituted dibenzofuran);

R ₂₀₁ to R ₂₁₁ are each independently hydrogen, deuterium, halogen, deuterium or halogen-substituted or unsubstituted (C1-C30)alkyl, substituted or unsubstituted (C3-C30)cycloalkyl, or substituted or unsubstituted (C6-30) aryl, and R ₂₀₈ to R ₂₁₁ are substituted or unsubstituted (3-30 membered) monocyclic or polycyclic alicyclic or (hetero)aromatic rings (eg, alkyl substituted with adjacent substituents connected to each other) or unsubstituted fluorene, alkyl-substituted or unsubstituted dibenzothiophene, alkyl-substituted or unsubstituted dibenzofuran);

f and g are each independently an integer of 1 to 3, and when f or g is each an integer of 2 or more, each R ₁₀₀ may be the same as or different from each other;

n is an integer from 1 to 3;

Specific examples of the phosphorescent dopant material are as follows.

The organic electroluminescent device of the present invention may further include at least one compound selected from the group consisting of arylamine-based compounds and styrylarylamine-based compounds in the organic material layer.

In addition, in the organic electroluminescent device of the present invention, at least one metal selected from the group consisting of group 1, group 2, 4-period transition metals, 5-period transition metals, lanthanide series metals, and organic metals of d-transition elements in the organic material layer , or one or more complex compounds containing these metals may be further included.

In the organic electroluminescent device of the present invention, at least one layer selected from a chalcogenide layer, a metal halide layer, and a metal oxide layer is provided on the inner surface of at least one of the pair of electrodes (hereinafter, these are referred to as “surface layers”). It is preferable to place a reference). Specifically, it is preferable to dispose a chalcogenide (including oxide) layer of silicon and aluminum on the surface of the anode on the light emitting medium layer side, and a metal halide layer or metal oxide layer on the surface of the cathode on the light emitting medium layer side. Driving stabilization of the organic electroluminescent device can be obtained by the surface layer. Preferable examples of the chalcogenide include SiO _X (1≤X≤2), AlO _X (1≤X≤1.5), SiON or SiAlON, and preferred examples of the metal halide include LiF, MgF ₂ , CaF ₂ , fluoride There are rare earth metals and the like, and preferable examples of the metal oxide include Cs ₂ O, Li ₂ O, MgO, SrO, BaO, CaO and the like.

A layer selected from a hole injection layer, a hole transport layer, or an electron blocking layer or a combination thereof may be used between the anode and the light emitting layer. A plurality of layers may be used as the hole injection layer for the purpose of lowering a hole injection barrier (or hole injection voltage) from the anode to the hole transport layer or the electron blocking layer, and two compounds may be used for each layer at the same time. A plurality of layers may also be used as the hole transport layer or the electron blocking layer.

A layer selected from an electron buffer layer, a hole blocking layer, an electron transport layer, or an electron injection layer or a combination thereof may be used between the light emitting layer and the cathode. A plurality of layers may be used as the electron buffer layer for the purpose of controlling electron injection and improving interface characteristics between the light emitting layer and the electron injection layer, and two compounds may be used for each layer at the same time. A plurality of layers may be used for the hole blocking layer or the electron transport layer, and a plurality of compounds may be used for each layer.

In the organic electroluminescent device of the present invention, it is also preferable to dispose a mixed region of an electron transfer compound and a reducing dopant or a mixed region of a hole transfer compound and an oxidizing dopant on the surface of at least one of the pair of electrodes. Since the electron transfer compound is reduced to negative ions in this way, it is easy to inject and transfer electrons from the mixed region to the light emitting medium. In addition, since the hole transfer compound is oxidized to become a cation, it becomes easy to inject and transfer holes from the mixed region to the light emitting medium. Preferable oxidizing dopants include various Lewis acids and acceptor compounds, and preferable reducing dopants include alkali metals, alkali metal compounds, alkaline earth metals, rare earth metals, and mixtures thereof. In addition, a white organic electroluminescent device having two or more light emitting layers may be manufactured by using the reducing dopant layer as a charge generation layer.

Formation of each layer of the organic electroluminescent device of the present invention is performed by any one of dry film formation methods such as vacuum deposition, sputtering, plasma, and ion plating, or wet film formation methods such as spin coating, dip coating, and flow coating. method can be applied. When forming a film of the first host compound and the second host compound of the present invention, co-evaporation or mixed deposition processes are performed.

In the case of the wet film formation method, a thin film is formed by dissolving or dispersing materials for forming each layer in an appropriate solvent such as ethanol, chloroform, tetrahydrofuran, or dioxane. It can be, and any one may be used as long as there is no problem in film formability.

In addition, the first and second host compounds of the present invention may be deposited by co-deposition or mixed deposition.

In addition, it is possible to manufacture a display device or lighting device using the organic electroluminescent device of the present invention.

Hereinafter, light emitting characteristics of a device including the host compound of the present invention will be described for a detailed understanding of the present invention.

[Device Manufacturing Example 1-1] OLED device manufacturing by co-depositing a first host compound and a second host compound as a host according to the present invention

An OLED device was prepared using the organic electroluminescent compound of the present invention. First, the transparent electrode ITO thin film (10Ω/□) obtained from glass for OLED (manufactured by GEOMATEC) is ultrasonically washed using trichlorethylene, acetone, ethanol and distilled water sequentially, and then stored in isopropanol before use. did Next, after mounting the ITO substrate on the substrate holder of the vacuum deposition equipment, N ⁴ ,N ^4' -diphenyl-N ⁴ ,N ^4' -bis(9-phenyl-9H-carbazole- 3-day) -[1,1'-biphenyl] -4,4'-diamine (compound HI-1) was added and the vacuum in the chamber was evacuated until it reached 10 ^-6 torr, and then the cell was charged with current. After applying and evaporating, a first hole injection layer having a thickness of 80 nm was deposited on the ITO substrate. Subsequently, 1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (compound HI-2) was put into another cell in the vacuum deposition equipment, and an electric current was applied to the cell to evaporate it, thereby forming a first hole A second hole injection layer having a thickness of 5 nm was deposited on the injection layer. Then N-([1,1'-biphenyl]-4-yl)-9,9-dimethyl-N-(4-(9-phenyl-9H-carbazole-3- 1) Phenyl) -9H-fluorene-2-amine (compound HT-1) was put thereinto, and an electric current was applied to the cell to evaporate it, thereby depositing a first hole transport layer having a thickness of 70 nm on the second hole injection layer. After forming the hole injection layer and the hole transport layer, the light emitting layer was deposited thereon as follows. After putting the first host compound and the second host compound as hosts in two cells in the vacuum deposition equipment, respectively, and compound D-96 as a dopant in another cell, respectively, the two host materials are added at the same rate of 1: 1 A light emitting layer having a thickness of 40 nm was deposited on the hole transport layer by doping the dopant in an amount of 3% by weight based on the total dopant and host by evaporating and simultaneously evaporating the dopant material at different rates. Then, in two other cells, 2,4-bis(9,9-dimethyl-9H-fluoren-2-yl)-6-(naphthalen-2-yl)-1,3,5-triazine (compound ET-1) and lithium quinolate (compound EI-1) were evaporated at the same rate of 1:1 to deposit an electron transport layer having a thickness of 30 nm on the light emitting layer. Then, after depositing lithium quinolate (compound EI-1) to a thickness of 2 nm as an electron injection layer, an Al cathode was deposited to a thickness of 80 nm using another vacuum deposition equipment to manufacture an OLED device.

[Device Manufacturing Examples 2-1 to 2-3] Manufacturing of OLED device by co-depositing a first host compound and a second host compound as a host according to the present invention

A first hole transport layer (compound HT-1) was deposited to a thickness of 10 nm, and then N,N-di([1,1′-biphenyl]-4-yl)-4 '-(9H-carbazol-9-yl)-[1,1'-biphenyl]-4-amine (compound HT-2) was added and evaporated by applying an electric current to the cell to form a 60° C. The same as in Device Preparation Example 1-1 except that a second hole transport layer having a thickness of nm was deposited and the first host compound and the second host compound of Preparation Examples 2-1 to 2-3 of [Table 1] were used as hosts. An OLED device was manufactured by the method.

[Comparative Example 1-1] Preparation of an OLED device containing only a first host compound as a host

An OLED device was manufactured in the same manner as in Device Preparation Example 1-1, except that only the first host compound of Comparative Example 1-1 in [Table 1] was used as a host of the light emitting layer.

[Comparative Examples 2-1 to 2-3] Preparation of an OLED device containing only a second host compound as a host

OLED devices were manufactured in the same manner as in Device Preparation Examples 2-1 to 2-3, except that only the second host compounds of Comparative Examples 2-1 to 2-3 of [Table 1] were used as the host of the light emitting layer.

The driving voltage, luminous efficiency, and CIE color coordinates based on 1,000 nit luminance of the organic EL device prepared as described above and the life time falling from 100% to 90% at a constant current based on 5,000 nits luminance were measured.

The emission characteristics of the organic electroluminescent devices prepared in Device Preparation Example 1-1, Comparative Example 1-1, Device Preparation Examples 2-1 to 2-3, and Comparative Examples 2-1 to 2-3 are shown in Table 1 below. was

[Table 1]

[Device Manufacturing Examples 3-1 to 3-13] Manufacturing of OLED device by co-depositing a first host compound and a second host compound as a host according to the present invention

The second hole injection layer is deposited to a thickness of 3 nm, the first hole transport layer is deposited to a thickness of 40 nm, the second hole transport layer is not deposited, and the dopant of the light emitting layer is compound D-1 or D-25. And, the electron transport layer was deposited at a thickness of 35 nm at a rate of 4:6, and the combination of the first host compound and the second host compound used as a host of the light emitting layer was prepared in Device Manufacturing Examples 3-1 to 3 shown in Table 2 below. An OLED device was manufactured in the same manner as in Device Preparation Example 1-1, except that the host of -13 was used.

[Device Production Example 4-1] OLED device fabrication by co-depositing a first host compound and a second host compound as a host according to the present invention

The first hole transport layer is deposited with a thickness of 10 nm, the second hole transport layer is deposited with a thickness of 30 nm using compound HT-3, the dopant of the light emitting layer is compound D-136, and used as a host of the light emitting layer OLED devices were manufactured in the same manner as in Device Preparation Examples 3-1 to 3-13, except that the host of Device Preparation Example 4-1 described in Table 2 was used as the combination of the first host compound and the second host compound.

[Comparative Example 3-1] Preparation of an OLED device containing only a first host compound as a host

OLED devices were manufactured in the same manner as in Device Preparation Examples 3-1 to 3-13, except that the first host compound used as the host of the light emitting layer was the host of Comparative Example 3-1 described in Table 2 below.

[Comparative Examples 4-1 to 4-12] Preparation of OLED device containing only the second host compound as a host

OLED devices were manufactured in the same manner as in Device Preparation Examples 3-1 to 3-13, except that the host of Comparative Examples 4-1 to 4-12 described in Table 2 was used as the second host compound used as the host of the light emitting layer. .

[Comparative Example 5-1] Preparation of an OLED device containing only a second host compound as a host

An OLED device was manufactured in the same manner as in Device Preparation Example 4-1, except that the host of Comparative Example 5-1 described in Table 2 was used as the second host compound used as the host of the light emitting layer.

The driving voltage, luminous efficiency, and CIE color coordinates based on 1,000 nit luminance of the organic electroluminescent device prepared as described above and the life time falling from 100% to 90% at a constant current based on 15,000 nits luminance were measured.

Light emission of the organic electroluminescent device prepared in Device Preparation Examples 3-1 to 3-13, Device Preparation Example 4-1, Comparative Example 3-1, Comparative Examples 4-1 to 4-12, and Comparative Example 5-1 The properties are shown in Table 2 below.

[Table 2]

The organic electroluminescent device of the present invention includes a light emitting layer including a host and a phosphorescent dopant, and the host is composed of a plurality of host compounds in a specific combination, thereby having an effect of having better lifespan characteristics than conventional devices.

Claims (7)

At least one light-emitting layer is provided between an anode and a cathode, the light-emitting layer includes a host and a phosphorescent dopant, the host is composed of a plurality of host compounds, and at least a first host compound among the plurality of host compounds is Represented by Chemical Formula 1, the second host compound is represented by Chemical Formula 2, an organic electroluminescent device.

In Formulas 1 and 2,
Ar ₁ is (C6-C30)aryl unsubstituted or substituted with (C6-C30)aryl;
L ₁ is a single bond or unsubstituted (C6-C30)arylene;
L ₂ is a single bond or a substituted or unsubstituted (C6-C30)arylene;
Here, the substituent of the substituted (C6-C30)arylene of L ₁ and L ₂ is deuterium;
X is O or S;
R ₁ to R ₂₄ are each independently hydrogen, deuterium, (C6-C30) aryl substituted or unsubstituted (C6-C60) aryl, or (C6-C30) aryl substituted or unsubstituted (3-30 membered) ) is heteroaryl; Adjacent substituents may be connected to each other to form a substituted or unsubstituted (C3-C30) monocyclic or polycyclic alicyclic or aromatic ring, and the carbon atoms of the formed alicyclic or aromatic ring are selected from nitrogen, oxygen and sulfur. can be replaced with one or more heteroatoms that are;
R ₂₅ to R ₃₂ are each independently hydrogen, deuterium, cyano, substituted or unsubstituted (C6-C60) aryl, substituted or unsubstituted (3-30 membered) heteroaryl, or substituted or unsubstituted tri( C6-C30) arylsilyl; Adjacent substituents may be connected to each other to form a substituted or unsubstituted (C3-C30) monocyclic or polycyclic alicyclic or aromatic ring, and the carbon atoms of the formed alicyclic or aromatic ring are selected from nitrogen, oxygen and sulfur. can be replaced with one or more heteroatoms that are;
Provided, that at least one of R ₂₅ to R ₃₂ is substituted or unsubstituted dibenzofuranyl, or substituted or unsubstituted dibenzothiophenyl, or R ₂₅ and R ₂₆ or R ₂₇ and R ₂₈ are connected to each other to be substituted. or unsubstituted benzofuran;
Ar ₂ is a substituted or unsubstituted (3-30 membered) heteroaryl;
The heteroaryl includes one or more heteroatoms selected from B, N, O, S, Si and P. The organic electroluminescent device according to claim 1, wherein Chemical Formula 1 is represented by one of the following Chemical Formulas 3 to 6.

In Formulas 3 to 6,
Ar ₁ , L ₁ , X and R ₁ to R ₂₄ are as defined in claim 1. According to claim 1, In Formulas 1 and 2, L ₁ and L ₂ are each independently represented by one of Formulas 7 to 19, the organic electroluminescent device.

In Formulas 7 to 19,
Xi to Xp are each independently hydrogen or deuterium. According to claim 1, wherein Ar ₂ in Formula 2 is a group consisting of pyrrolyl, imidazolyl, pyrazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, pyridyl, pyrazinyl, pyrimidinyl and pyridazinyl Is a single ring heteroaryl selected from, benzoimidazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, naphthyridinyl, quinoxali An organic electroluminescent device that is a fused ring-based heteroaryl selected from the group consisting of yl, carbazolyl and phenanthridinyl. According to claim 1, wherein R ₂₅ to R ₃₂ in Formula 2 are each independently hydrogen, cyano, tri(C6-C10) arylsilyl substituted or unsubstituted (C6-C15) aryl, (C6-C12) aryl-substituted or unsubstituted (10-20 membered) heteroaryl, or unsubstituted tri(C6-C10)arylsilyl; Adjacent substituents are connected to each other to form substituted or unsubstituted benzene, substituted or unsubstituted indole, substituted or unsubstituted benzoindole, substituted or unsubstituted indene, substituted or unsubstituted benzofuran, or substituted or unsubstituted benzo can form thiophenes; Provided, that at least one of R ₂₅ to R ₃₂ is substituted or unsubstituted dibenzofuranyl, or substituted or unsubstituted dibenzothiophenyl, or R ₂₅ and R ₂₆ or R ₂₇ and R ₂₈ are connected to each other to be substituted. Or to form an unsubstituted benzofuran, an organic electroluminescent device. The organic electroluminescent device according to claim 1, wherein the compound represented by Formula 1 is selected from the following compounds.

The organic electroluminescent device according to claim 1, wherein the compound represented by Formula 2 is selected from the following compounds.