Organic electroluminescent device and nitrogen-containing compound for organic electroluminescent device

Abstract

Provided are organic electroluminescent devices and nitrogen-containing compounds for use in organic electroluminescent devices. The organic electroluminescent device of an embodiment of the present disclosure includes a first electrode, a hole transport region disposed on the first electrode, an emission layer disposed on the hole transport region, an electron transport region disposed on the emission layer, and a second electrode disposed on the electron transport region. The emission layer may include a nitrogen-containing compound represented by Formula 1, thereby exhibiting a long service life. In Formula 1, at least one of A1 to A5 is represented by Formula 2, and at least another of A1 to A5 is represented by Formula 3:

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0001963, filed on January 7, 2020, which is hereby incorporated by reference herein in its entirety. Technical Field

[0002] One or more aspects of the embodiments of the present disclosure relate to an organic electroluminescent device and a nitrogen-containing compound for the organic electroluminescent device. Background Art

[0003] Organic electroluminescent displays (ELDs) are currently being developed as image display devices. Unlike liquid crystal displays (LCDs), ELDs are self-luminescent displays. In these displays, holes and electrons injected from a first electrode and a second electrode recombine in an emissive layer, causing the luminescent material (including organic compounds) in the emissive layer to emit light, thereby achieving display.

[0004] When applying organic electroluminescent devices to display devices, there is a demand for organic electroluminescent devices having low driving voltage, high luminous efficiency and long service life (lifespan), and there is a demand for new materials that can stably obtain such characteristics of organic electroluminescent devices.

[0005] In recent years, in order to realize high-efficiency organic electroluminescent devices, materials utilizing triplet state energy phosphorescence emission, delayed fluorescence triplet-triplet annihilation (TTA) (in which singlet excitons are generated by collision of triplet excitons), and / or thermally activated delayed fluorescence (TADF) are being developed. Summary of the Invention

[0006] One or more aspects of the embodiments of the present disclosure relate to an organic electroluminescent device having a long lifetime and high efficiency and a nitrogen-containing compound used therein.

[0007] One or more aspects of embodiments of the present disclosure relate to an organic electroluminescent device including a thermally activated delayed fluorescent emission material and a nitrogen-containing compound used as the thermally activated delayed fluorescent emission material.

[0008] One or more example embodiments of the present disclosure provide an organic electroluminescent device, comprising: a first electrode; a hole transport region disposed on the first electrode; an emission layer disposed on the hole transport region; an electron transport region disposed on the emission layer; and a second electrode disposed on the electron transport region, wherein the emission layer contains a nitrogen-containing compound, the nitrogen-containing compound including an aromatic monocyclic ring having a substituted or unsubstituted carbazole group, a substituted or unsubstituted triazine group, and a substituted or unsubstituted triazatrimer indenyl group as substituents.

[0009] In an embodiment, the emission layer may be to emit delayed fluorescence and may be a delayed fluorescence emission layer including a first compound and a second compound, and the first compound may include a nitrogen-containing compound.

[0010] In an embodiment, the nitrogen-containing compound may be represented by Formula 1:

[0011] Formula 1

[0012]

[0013] In Formula 1, Ar1 and Ar2 may each independently be a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, A1 to A5 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, or A1 to A5 may each independently be represented by Formula 2 or Formula 3, wherein at least one of A1 to A5 is represented by Formula 2, and at least another of A1 to A5 is represented by Formula 3:

[0014] Formula 2

[0015]

[0016] Formula 3

[0017]

[0018] In Formulae 2 and 3, Ar3 and Ar4 may each independently be a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, R1 to R5 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted thiol group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, and R1 to R5 may optionally be bonded to an adjacent ring to form a ring, and a to e may each independently be an integer from 0 to 4.

[0019] When a in Formula 2 is an integer of 2 or greater, a pair of adjacent R1s may form a condensed ring structure having any one of Formulas 7-1 to 7-4 (e.g., forming a condensed ring structure according to any one of Formulas 7-1 to 7-4):

[0020]

[0021] In equations 7-1 to 7-4, R a to R g They may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted thiol group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, and j to m may each independently be an integer from 0 to 4.

[0022] Ar1 to Ar4 can each independently be represented by Formula 8:

[0023] Formula 8

[0024]

[0025] In Formula 8, Y1 to Y5 may each independently be CX or N,

[0026] X may be a hydrogen atom, a deuterium atom, an alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and X may be optionally bonded to an adjacent ring to form a ring.

[0027] In an embodiment, Formula 1 may be expressed by any one of Formulas 4-1 to 4-4:

[0028] Formula 4-1

[0029]

[0030] Formula 4-2

[0031]

[0032] Formula 4-3

[0033]

[0034] Formula 4-4

[0035]

[0036] In Formulae 4-1 to 4-4, Ar1 to Ar4, A1 to A4, R1 to R5, and a to e may all independently be the same as defined in Formulae 1 to 3.

[0037] In an embodiment, Formula 1 may be expressed by any one of Formulas 5-1 to 5-4:

[0038] Formula 5-1

[0039]

[0040] Formula 5-2

[0041]

[0042] Formula 5-3

[0043]

[0044] Formula 5-4

[0045]

[0046] In Formulae 5-1 to 5-4, Ar1 to Ar4, A1 to A3, A5, R1 to R5, and a to e may all independently be the same as defined in Formulae 1 to 3.

[0047] In an embodiment, Formula 1 may be represented by Formula 6-1 or Formula 6-2:

[0048] Formula 6-1

[0049]

[0050] Formula 6-2

[0051]

[0052] In Formula 6-1 and Formula 6-2, Ar1 to Ar4, A1, A2, A4, A5, R1 to R5, and a to e may all independently be the same as defined in Formula 1 to Formula 3.

[0053] In an embodiment, the nitrogen-containing compound represented by Formula 1 may be any one of the compounds represented by Compound Group 1.

[0054] An embodiment of the present disclosure provides a nitrogen-containing compound represented by Formula 1. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The accompanying drawings illustrate example embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. In the drawings:

[0056] Figure 1 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure;

[0057] Figure 2 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure;

[0058] Figure 3 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure; and

[0059] Figure 4 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0060] The present disclosure may have various modifications and may be implemented in different forms, and example embodiments will be explained in more detail with reference to the accompanying drawings. However, the present disclosure may be implemented in different forms and should not be interpreted as being limited to the embodiments set forth herein. On the contrary, all modifications, equivalents, and substitutes within the spirit and technical scope of the present disclosure should be included in the present disclosure.

[0061] In the description, it will be understood that when an element or layer is referred to as being “on,” “connected to,” or “coupled to” another element or layer, the element or layer can be directly on, directly connected to, or directly coupled to the other element or layer, or intervening elements or layers may be present. When an element is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element, there are no intervening elements present.

[0062] The same reference numerals always represent the same elements, and repeated descriptions thereof may not be provided. In addition, in the drawings, the thicknesses, ratios, and sizes of elements may be exaggerated for the sake of effective description of the technical contents.

[0063] The term "and / or" includes any and all combinations of one or more of the associated listed items. As used herein, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms as well.

[0064] As used herein, expressions such as "at least one of," "one of," and "selected from," when preceding (preceding) a list of elements, modify the entire list of elements and do not modify the individual elements in the list. Furthermore, when describing embodiments of the present disclosure, the use of "may" means "one or more embodiments of the present disclosure."

[0065] It will be understood that although the terms "first," "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element may be named a second element, and similarly, a second element may be named a first element without departing from the scope of the exemplary embodiments of the present disclosure. Unless the context clearly indicates otherwise, terms in the singular may include plural forms.

[0066] In addition, terms such as "below", "lower", "above" and / or "upper" are used to describe the relationship of the structures shown in the drawings. The terms are relative concepts and are used with reference to the directions indicated in the drawings.

[0067] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will also be understood that, unless expressly defined herein, terms should be interpreted as having a meaning consistent with their meaning in the context of the relevant art (such as, as defined in a general dictionary), and that terms should not be interpreted in an idealized or overly formal sense.

[0068] It should be understood that the terms "comprises," "includes," and / or "has" and their variations are intended to indicate the presence of the stated features, integers, steps, operations, elements, components, or combinations thereof in the disclosure, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0069] Hereinafter, an organic electroluminescent device according to an embodiment of the present disclosure and a compound of the embodiment included therein will be described with reference to the accompanying drawings.

[0070] Figures 1 to 4 1 is a cross-sectional view schematically showing an organic electroluminescent device according to an embodiment of the present disclosure. Figures 1 to 4In each organic electroluminescent device 10 , the first electrode EL1 and the second electrode EL2 are disposed to face each other, and the emission layer EML may be disposed between the first electrode EL1 and the second electrode EL2 .

[0071] In some embodiments, in addition to the emission layer EML, each organic electroluminescent device 10 may further include multiple functional layers located between the first electrode EL1 and the second electrode EL2. The multiple functional layers may include a hole transport region HTR and an electron transport region ETR. For example, each organic electroluminescent device 10 according to an embodiment may include a first electrode EL1, a hole transport region HTR, an emission layer EML, an electron transport region ETR, and a second electrode EL2 stacked in sequence. In some embodiments, the organic electroluminescent device 10 of the embodiment may include a capping layer CPL disposed on the second electrode EL2.

[0072] The organic electroluminescent device 10 of the embodiment may include a nitrogen-containing compound of the embodiment to be described later in the emission layer EML provided between the first electrode EL1 and the second electrode EL2. However, the embodiment is not limited thereto, and the organic electroluminescent device 10 of the embodiment may include the nitrogen-containing compound according to the embodiment not only in the emission layer EML but also in the hole transport region HTR and / or the electron transport region ETR (the hole transport region HTR and the electron transport region ETR are among the multiple functional layers provided between the first electrode EL1 and the second electrode EL2), and / or may include the nitrogen-containing compound according to the embodiment in the cap layer CPL provided on the second electrode EL2.

[0073] and Figure 1 In comparison, Figure 2 FIG1 shows a cross-sectional view of an organic electroluminescent device 10 of an embodiment, in which the hole transport region HTR includes a hole injection layer HIL and a hole transport layer HTL, and the electron transport region ETR includes an electron injection layer EIL and an electron transport layer ETL. Figure 1 In comparison, Figure 3 1 shows a cross-sectional view of an organic electroluminescent device 10 of an embodiment, in which the hole transport region HTR includes a hole injection layer HIL, a hole transport layer HTL and an electron blocking layer EBL, and the electron transport region ETR includes an electron injection layer EIL, an electron transport layer ETL and a hole blocking layer HBL. Figure 2 In comparison, Figure 4 FIG. 1 is a cross-sectional view of an organic electroluminescent device 10 according to an embodiment, which includes a cap layer CPL provided on the second electrode EL2 .

[0074] The first electrode EL1 may be conductive. The first electrode EL1 may be formed of a metal alloy and / or a conductive compound. The first electrode EL1 may be a pixel electrode or a positive electrode. The first electrode EL1 may be a transmissive electrode, a transflective electrode, or a reflective electrode. When the first electrode EL1 is a transmissive electrode, the first electrode EL1 may include a transparent metal oxide (such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO)). When the first electrode EL1 is a transflective electrode or a reflective electrode, the first electrode EL1 may include silver (Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), LiF / Ca, LiF / Al, molybdenum (Mo), titanium (Ti), indium (In), zinc (Zn), tin (Sn), compounds thereof, mixtures thereof (e.g., a mixture of Ag and Mg), or oxides thereof (e.g., ITO, IZO). In some embodiments, the first electrode EL1 may have a multi-layer structure including a reflective layer or a transflective layer formed of the above materials and a transparent conductive layer formed of ITO, IZO, ZnO, ITZO, etc. For example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO, but the embodiments of the present disclosure are not limited thereto. The thickness of the first electrode EL1 may be approximately to approximately For example, approximately to approximately

[0075] The hole transport region HTR is disposed on the first electrode EL1. The hole transport region HTR may include at least one of a hole injection layer HIL, a hole transport layer HTL, a hole buffer layer, and an electron blocking layer EBL.

[0076] The hole transport region HTR may have a single layer formed of a single material, a single layer formed of a plurality of different materials, or a multi-layered structure including a plurality of layers formed of a plurality of different materials.

[0077] For example, the hole transport region HTR may have a single-layer structure of a hole injection layer HIL or a hole transport layer HTL, or may have a single-layer structure formed of a hole injection material and a hole transport material. In some embodiments, the hole transport region HTR may have a single-layer structure formed of a plurality of different materials, or may have a structure in which a hole injection layer HIL / hole transport layer HTL, a hole injection layer HIL / hole transport layer HTL / hole buffer layer, a hole injection layer HIL / hole buffer layer, a hole transport layer HTL / hole buffer layer, or a hole injection layer HIL / hole transport layer HTL / electron blocking layer EBL is stacked in this order from the first electrode EL1, but the embodiment is not limited thereto.

[0078] The hole transport region HTR may be formed using any suitable method such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and / or laser induced thermal imaging (LITI) method.

[0079] The hole injection layer HIL may include, for example, a phthalocyanine compound (such as copper phthalocyanine), N,N'-diphenyl-N,N'-bis[4-(di-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine (DNTPD), 4,4',4"-[tris(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4',4"-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tris[N-(2-naphthyl)-N-phenylamino]triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) salt) (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), polyaniline / camphorsulfonic acid (PANI / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPD), triphenylamine-containing polyetherketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexanitrile (HAT-CN), etc.

[0080] The hole transport layer HTL may include any suitable material available in the art. For example, the hole transport layer HTL may also include carbazole derivatives (such as N-phenylcarbazole and / or polyvinylcarbazole), fluorene derivatives, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), triphenylamine derivatives (such as 4,4',4"-tris(N-carbazolyl)triphenylamine (TCTA)), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPD), 4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl (HMTPD), 1,3-bis(N-carbazolyl)benzene (mCP), etc.

[0081] The electron blocking layer EBL may include, for example, carbazole derivatives (such as N-phenylcarbazole and / or polyvinylcarbazole), fluorene derivatives, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), triphenylamine derivatives (such as 4,4',4"-tris(N-carbazolyl)triphenylamine (TCTA)), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPD), 4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl (HMTPD), mCP, etc.

[0082] The hole transport region HTR may have a size of approximately to approximately (For example, approximately to approximately The thickness of the hole injection layer HIL can be, for example, about to approximately The thickness of the hole transport layer HTL may be approximately to approximately For example, the thickness of the electron blocking layer EBL may be about to approximately When the thicknesses of the hole transport region HTR, the hole injection layer HIL, the hole transport layer HTL, and the electron blocking layer EBL satisfy the above ranges, satisfactory hole transport properties may be achieved without significantly increasing driving voltage.

[0083] In addition to the above materials, the hole transport region HTR may further include a charge generating material to improve conductivity. The charge generating material may be substantially uniformly or non-uniformly dispersed in the hole transport region HTR. The charge generating material may be, for example, a p-dopant. The p-dopant may be one of a quinone derivative, a metal oxide, and a cyano-containing compound, but is not limited thereto. For example, non-limiting examples of p-dopants include quinone derivatives (such as tetracyanoquinodimethane (TCNQ) and / or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ)), metal oxides (such as tungsten oxide and / or molybdenum oxide), and the like.

[0084] In some embodiments, in addition to the hole injection layer HIL and the hole transport layer HTL, the hole transport region HTR may further include at least one of a hole buffer layer and an electron blocking layer EBL. The hole buffer layer can compensate for the resonance distance of the wavelength of light emitted from the emission layer EML, thereby improving luminous efficiency. Materials that may be included in the hole transport region HTR may also be included in the hole buffer layer. The electron blocking layer EBL is a layer used to prevent or reduce electron injection from the electron transport region ETR into the hole transport region HTR.

[0085] The emission layer EML is disposed on the hole transport region HTR. The thickness of the emission layer EML may be, for example, approximately to approximately or approximately to approximately The emission layer EML may have a single layer formed of a single material, a single layer formed of a plurality of different materials, or a multi-layered structure having a plurality of layers formed of a plurality of different materials.

[0086] The emission layer EML may emit one of red light, green light, blue light, white light, yellow light, and cyan light, and may include a fluorescent emission material or a phosphorescent emission material.

[0087] In an embodiment, the emission layer EML may be a fluorescent emission layer. For example, some of the light emitted from the emission layer EML may be generated by thermally activated delayed fluorescence (TADF). In some embodiments, the emission layer EML may include a luminescent component that emits thermally activated delayed fluorescence (TADF), for example, the emission layer EML may emit blue light via thermally activated delayed fluorescence.

[0088] The emission layer EML of the organic electroluminescent device 10 of the embodiment includes the nitrogen-containing compound according to the embodiment of the present disclosure.

[0089] In the description, the term "substituted or unsubstituted" refers to a state in which the group consisting of deuterium atoms, halogen atoms, cyano groups, nitro groups, amino groups (or amido groups), silyl groups, oxy groups, sulfenyl groups, sulfinyl groups, sulfonyl groups, carbonyl groups, boron groups, phosphine oxide groups, phosphine sulfide groups, alkyl groups, alkenyl groups, alkoxy groups, hydrocarbon ring groups, aryl groups and heterocyclic groups is unsubstituted or is substituted with at least one substituent. In certain embodiments, each of the above-mentioned substituents may be further substituted or unsubstituted. For example, biphenyl groups may be interpreted as aryl groups, or may be interpreted as phenyl groups substituted with phenyl groups.

[0090] In the description, the term "bonding to an adjacent group to form a ring" may refer to a state in which the adjacent group is bonded to form a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle. The hydrocarbon ring may be an aliphatic hydrocarbon ring or an aromatic hydrocarbon ring. The heterocycle may be an aliphatic heterocycle or an aromatic heterocycle. The ring formed by bonding to the adjacent group may be monocyclic or polycyclic. In some embodiments, the ring formed by bonding to each other may be connected to another ring to form a spiro structure.

[0091] In the description, the term "adjacent groups" can refer to substituents on the same atom or site, substituents directly attached to a radical atom or site, or substituents that are spatially adjacent to the corresponding substituent (e.g., within intramolecular bonding distance). For example, the two methyl groups in 1,2-dimethylbenzene can be interpreted as "adjacent groups" to each other, and the two ethyl groups in 1,1-diethylcyclopentane can be interpreted as "adjacent groups" to each other.

[0092] In the description, non-limiting examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0093] In the description, unless otherwise specified, the alkyl group may be a chain alkyl group or a cycloalkyl group. The number of carbon atoms in the alkyl group may be 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Non-limiting examples of alkanyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, tert-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyl Examples of cycloalkyl groups include cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl, cyclooctyl, and the like. Non-limiting examples of cycloalkyl groups include cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl, and cyclooctyl.

[0094] In the description, the term "alkenyl" may refer to a hydrocarbon group including at least one carbon-carbon double bond in the middle or at the end of an alkyl group having 2 or more carbon atoms. The alkenyl group may be straight-chain or branched. The number of carbon atoms in the alkenyl group is not particularly limited and may be 2 to 30, 2 to 20, or 2 to 10. Non-limiting examples of alkenyl groups include vinyl, 1-butenyl, 1-pentenyl, 1,3-butadienylaryl, styryl, styrylvinyl, etc.

[0095] In the description, the term "alkynyl" may refer to a hydrocarbon group including at least one carbon-carbon triple bond in the middle or at the end of an alkyl group having 2 or more carbon atoms. The alkynyl group may be straight-chain or branched. The number of carbon atoms in the alkynyl group is not particularly limited and may be 2 to 30, 2 to 20, or 2 to 10. Non-limiting examples of alkynyl groups include ethynyl, propynyl, etc.

[0096] In the description, the term "hydrocarbon ring group" may refer to any functional group or substituent derived from an aliphatic hydrocarbon ring or any functional group or substituent derived from an aromatic hydrocarbon ring. The number of ring-forming carbon atoms in the hydrocarbon ring group may be 5 to 60, 5 to 30, or 5 to 20.

[0097] In the description, the term "aryl" may refer to any functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group may be a monocyclic aryl group or a polycyclic aryl group. The number of ring carbon atoms in the aryl group may be 6 to 30, 6 to 20, or 6 to 15. Non-limiting examples of aryl groups include phenyl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl, biphenyl, terphenyl, quaterphenyl, pentyl, hexaphenyl, benzo[9,10]phenanthrenyl, pyrenyl, benzofluoranthenyl, Ji et al.

[0098] In the description, the fluorenyl group may be substituted, and two substituents (for example, two substituents at the 9H position) may be combined with each other to form a spiro structure. Non-limiting examples of the substituted fluorenyl group are as follows.

[0099] However, embodiments of the present disclosure are not limited thereto.

[0100]

[0101] In the description, the term "heterocyclic group" may refer to any functional group or substituent derived from a ring containing at least one of boron (B), oxygen (O), nitrogen (N), phosphorus (P), silicon (Si), and sulfur (S) as a heteroatom. The heterocyclic group may be an aliphatic heterocyclic group or an aromatic heterocyclic group. The aromatic heterocyclic group may be a heteroaryl group. The aliphatic heterocyclic ring and the aromatic heterocyclic ring may be monocyclic or polycyclic.

[0102] In the description, the heterocyclic group may include at least one of B, O, N, P, Si and S as a heteroatom. When the heterocyclic group contains two or more heteroatoms, the two or more heteroatoms may be the same as or different from each other. The heterocyclic group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group, and includes a heteroaryl group. The number of ring carbon atoms in the heterocyclic group may be 2 to 30, 2 to 20 or 2 to 10.

[0103] In the description, the aliphatic heterocyclic group may include at least one of B, O, N, P, Si, and S as a heteroatom. The number of ring-forming carbon atoms in the aliphatic heterocyclic group may be 2 to 30, 2 to 20, or 2 to 10. Non-limiting examples of the aliphatic heterocyclic group include an oxirane group, an oxirane group, a pyrrolidinyl group, a piperidinyl group, a tetrahydrofuranyl group, a tetrahydrothiophenyl group, a thiane group, a tetrahydropyranyl group, and a 1,4-dioxanyl group.

[0104] In the description, the heteroaryl group may include at least one of B, O, N, P, Si and S as a heteroatom. When the heteroaryl group contains two or more heteroatoms, the two or more heteroatoms may be the same as or different from each other. The heteroaryl group may be a monocyclic heteroaryl group or a polycyclic heteroaryl group. The number of ring carbon atoms in the heteroaryl group may be 2 to 30, 2 to 20 or 2 to 10. Non-limiting examples of heteroaryl groups include thienyl, furanyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridinyl, pyridazinyl, pyrazinyl, quinolinyl, quinazolinyl, quinoxalinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolinyl, indolyl, carbazolyl, N-arylcarbazolyl, N-heteroarylcarbazolyl, N-alkylcarbazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothienyl, dibenzothienyl, thienothiphenyl, benzofuranyl, phenanthrolinyl, isoxazolyl, thiadiazolyl, phenothiazinyl, dibenzothiazolyl, dibenzofuranyl, and the like.

[0105] In the description, the number of carbon atoms in the amino group is not particularly limited, but can be 1 to 30. The amino group can include an alkylamino group, an arylamino group, or a heteroarylamino group. Non-limiting examples of the amino group include a methylamino group, a dimethylamino group, a phenylamino group, a diphenylamino group, a naphthylamino group, a 9-methyl-anthrylamino group, and the like.

[0106] In the description, the thio group may include an alkylthio group and an arylthio group.

[0107] In the description, the oxy group can be linear, branched or cyclic. The oxy group can be an alkoxy group or an aryloxy group. The term "alkoxy" can refer to an alkyl group in which the oxygen atom is bound to an alkyl group as defined above. The number of carbon atoms in the alkoxy group is not limited, but can be, for example, 1 to 20 or 1 to 10. Non-limiting examples of alkoxy groups include methoxy, ethoxy, propoxy, isobutoxy, sec-butoxy, pentyloxy, isopentyloxy, hexyloxy, etc. The term "aryloxy" can refer to an aryl group in which the oxygen atom is bound to an aryl group as defined above. The number of carbon atoms in the aryloxy group can be, for example, 6 to 30 as ring carbon atoms, but is not limited thereto. Non-limiting examples of aryloxy groups include phenoxy, p-tolyloxy, m-tolyloxy, 3,5-dimethyl-phenoxy, 2,4,6-trimethylphenoxy, m-tert-butylphenoxy, 3-biphenyloxy, 4-biphenyloxy, 1-naphthyloxy, 2-naphthyloxy, 4-methyl-1-naphthyloxy, 5-methyl-2-naphthyloxy, 1-anthracenyloxy, 2-anthracenyloxy, 9-anthracenyloxy, 1-phenanthracenyloxy, 3-phenanthracenyloxy, 9-phenanthracenyloxy, and the like.

[0108] In the description, “-*” indicates the connection point.

[0109] The nitrogen-containing compound according to an embodiment of the present disclosure may be represented by Formula 1:

[0110] Formula 1

[0111]

[0112] In Formula 1, Ar1 and Ar2 may each independently be a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms.

[0113] In Formula 1, A1 to A5 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, or A1 to A5 may each independently be represented by Formula 2 or Formula 3, wherein at least one of A1 to A5 may be represented by Formula 2, and at least another one of A1 to A5 may be represented by Formula 3:

[0114] Formula 2

[0115]

[0116] Formula 3

[0117]

[0118] In Formula 2 and Formula 3, R1 to R5 can each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted thiol group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and R1 to R5 can be optionally bonded to adjacent rings to form a ring.

[0119] In Formula 2, a may be an integer of 0 to 4. When a is 2 or greater, a plurality of R1s may be the same as or different from each other.

[0120] In Formula 2, b may be an integer of 0 to 4. When b is 2 or greater, a plurality of R2s may be the same as or different from each other.

[0121] In Formula 3, c may be an integer from 0 to 4. When c is 2 or greater, a plurality of R3 may be the same as or different from each other.

[0122] In Formula 3, d may be an integer of 0 to 4. When d is 2 or greater, a plurality of R4s may be the same as or different from each other.

[0123] In Formula 3, e may be an integer from 0 to 4. When e is 2 or greater, a plurality of R5 may be the same as or different from each other.

[0124] In Formula 3, Ar3 and Ar4 may each independently be a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms.

[0125] In an embodiment, Ar1 to Ar4 may each be independently represented by Formula 8:

[0126] Formula 8

[0127]

[0128] In Formula 8, Y1 to Y5 may each independently be CX or N, X may be a hydrogen atom, a deuterium atom, an alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and X may optionally bind to an adjacent ring to form a ring.

[0129] In an embodiment, when a in Formula 2 is an integer of 2 or greater, a pair of adjacent R1s may form a condensed ring structure having any one of Formulas 7-1 to 7-4 (e.g., forming a condensed ring structure according to any one of Formulas 7-1 to 7-4):

[0130]

[0131] In equations 7-1 to 7-4, R a to R g Each of them may independently be a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted thiol group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms.

[0132] In Formula 7-1 to Formula 7-4, j to m may each independently be an integer from 0 to 4. When j is 2 or greater, a plurality of R c can be the same as or different from each other; when k is 2 or greater, multiple R e can be the same as or different from each other; when l is 2 or greater, multiple R f can be the same as or different from each other; when m is 2 or greater, multiple R g They may be the same as or different from each other.

[0133] In an embodiment, Ar1 and Ar2 in Formula 1 may each independently be a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophenyl group.

[0134] In an embodiment, any one of A1 to A5 in Formula 1 may be expressed by Formula 2, and another one of A1 to A5 may be expressed by Formula 3.

[0135] In an embodiment, A1 to A5 in Formula 1 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted arylamine group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted pyrene group, a substituted or unsubstituted fluorenyl group, or a substituted or unsubstituted dibenzothiophene group, or A1 to A5 in Formula 1 may each independently be represented by Formula 2 or Formula 3.

[0136] In an embodiment, Formula 2 may be a substituent at the ortho position of the triazine group in Formula 1. For example, Formula 1 may be represented by any one of Formulas 4-1 to 4-4:

[0137] Formula 4-1

[0138]

[0139] Formula 4-2

[0140]

[0141] Formula 4-3

[0142]

[0143] Formula 4-4

[0144]

[0145] In Formulae 4-1 to 4-4, Ar1 to Ar4, A1 to A4, R1 to R5, and a to e may all independently be the same as defined in Formulae 1 to 3.

[0146] In an embodiment, Formula 2 may be a substituent at the meta position of the triazine group in Formula 1. For example, Formula 1 may be represented by any one of Formulas 5-1 to 5-4:

[0147] Formula 5-1

[0148]

[0149] Formula 5-2

[0150]

[0151] Formula 5-3

[0152]

[0153] Formula 5-4

[0154]

[0155] In Formulae 5-1 to 5-4, Ar1 to Ar4, A1 to A3, A5, R1 to R5, and a to e may all independently be the same as defined in Formulae 1 to 3.

[0156] In an embodiment, Formula 2 may be a substituent at the para position of the triazine group in Formula 1. For example, Formula 1 may be represented by Formula 6-1 or Formula 6-2:

[0157] Formula 6-1

[0158]

[0159] Formula 6-2

[0160]

[0161] In Formula 6-1 and Formula 6-2, Ar1 to Ar4, A1, A2, A4, A5, R1 to R5, and a to e may all independently be the same as defined in Formula 1 to Formula 3.

[0162] In an embodiment, the nitrogen-containing compound represented by Formula 1 may be any one selected from among the compounds represented by Compound Group 1, however, embodiments of the present disclosure are not limited thereto:

[0163] Compound Group 1

[0164]

[0165]

[0166]

[0167]

[0168] The nitrogen-containing compound can be used in the organic electroluminescent device 10 of the embodiment to improve the luminous efficiency and service life of the organic electroluminescent device 10. For example, the nitrogen-containing compound can be used in the emission layer EML of the organic electroluminescent device 10 of the embodiment to improve the luminous efficiency and / or service life of the organic electroluminescent device 10.

[0169] In an embodiment, the emission layer EML may be a delayed fluorescent emission layer including a first compound and a second compound, and the nitrogen-containing compound of the embodiment represented by Formula 1 may be included in the first compound of the emission layer EML. For example, the first compound may be a dopant, and the second compound may be a host.

[0170] In an embodiment, the host may be a host that emits delayed fluorescence, and the dopant may be a dopant that emits delayed fluorescence. In some embodiments, the nitrogen-containing compound of the embodiment represented by Formula 1 may be included in the emission layer EML as a dopant material. For example, the nitrogen-containing compound of the embodiment represented by Formula 1 may be used as a TADF dopant.

[0171] In some embodiments, the organic electroluminescent device 10 of the embodiment may include multiple emission layers. The multiple emission layers may be stacked sequentially. For example, the organic electroluminescent device 10 including multiple emission layers may emit white light. The organic electroluminescent device 10 including multiple emission layers may be an organic electroluminescent device having a tandem (or "cascade") structure. When the organic electroluminescent device 10 includes multiple emission layers, at least one emission layer EML may include the nitrogen-containing compound according to the present disclosure as described above.

[0172] The emission layer EML may further include a dopant, and any suitable material may be used as the dopant. For example, styryl derivatives (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]stilbene (DPAVB) and / or N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalene-2-yl)vinyl)phenyl)-N-phenylaniline (N-BDAVBi)), perylene and / or or its derivatives (e.g., 2,5,8,11-tetra-tert-butylperylene (TBPe)), pyrene and / or its derivatives (e.g., 1,1'-dipyrene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene and / or 1,6-bis(N,N-diphenylamino)pyrene) and 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi) may be used as a dopant, but the embodiment is not limited thereto.

[0173] The emission layer EML may also include any suitable material available in the art as a host material. For example, the emission layer EML may include, but is not limited to, tris(8-hydroxyquinoline)aluminum (Alq3), bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), 4,4'-bis(carbazol-9-yl)biphenyl (CBP), 1,3-bis(carbazol-9-yl)benzene (mCP), 2,8-bis(diphenylphosphino)dibenzo[b,d]furan (PPF), 4,4',4"-tris(carbazol-9-yl)-triphenylamine (TCTA), poly(N-vinylcarbazole) (PVK), 9,10-di(naphthalene-2-yl)anthracene (ADN), 2-tert-butyl-9,10-di(naphthalene-2-yl)anthracene. At least one of (TBADN), distyrylarylene (DSA), 4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl (CDBP), 2-methyl-9,10-bis(naphthalene-2-yl)anthracene (MADN), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH-2), hexaphenylcyclotrisiloxane (DPSiO3), octaphenylcyclotetrasiloxane (DPSiO4) and 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi) is used as the host material.

[0174] When the emission layer EML is to emit red light, the emission layer EML may further include, for example, a fluorescent material containing PBD: tris(dibenzoylmethane)mono(phenanthroline)europium (Eu(DBM)3(Phen)) and / or perylene. When the emission layer EML is to emit red light, the dopant included in the emission layer EML may be, for example, a metal complex or an organic metal complex (such as bis(1-phenylisoquinolinolato)iridium acetylacetonate (PIQIr(acac)), tris(1-phenylquinolinolato)iridium (PQIr) and / or platinum octaethylporphyrin (PtOEP)), rubrene and / or its derivatives and / or 4-dicyanomethylidene-2-(m-dimethylaminophenylvinyl)-6-methyl-4H-pyran (DCM) and / or its derivatives.

[0175] When the emission layer EML is to emit green light, the emission layer EML may further include, for example, a fluorescent material including tris(8-hydroxyquinoline)aluminum (Alq3). When the emission layer EML is to emit green light, the dopant included in the emission layer EML may be, for example, selected from metal complexes or organometallic complexes (such as f-tris(2-phenylpyridine)iridium (Ir(ppy)3) and coumarin and / or its derivatives.

[0176] When the emission layer EML is to emit blue light, the emission layer EML may further include, for example, a fluorescent material selected from the group consisting of spiro-DPVBi, spiro-6P, distyrylbenzene (DSB), distyrylarylene (DSA), polyfluorene (PFO)-based polymers, and poly(p-phenylene vinylene) (PPV)-based polymers. When the emission layer EML is to emit blue light, the dopant contained in the emission layer EML may be, for example, a metal complex or an organometallic complex (such as (4,6-F2ppy)2Irpic) or perylene and / or its derivatives.

[0177] exist Figures 1 to 4 In the organic electroluminescent device 10 of the embodiment shown in FIG, the electron transport region ETR is provided on the emission layer EML. The electron transport region ETR may include at least one of a hole blocking layer HBL, an electron transport layer ETL, and an electron injection layer EIL, but the embodiment is not limited thereto.

[0178] The electron transport region ETR may have a single layer formed of a single material, a single layer formed of a plurality of different materials, or a multilayer structure including a plurality of layers formed of a plurality of different materials.

[0179] For example, the electron transport region ETR may have a single-layer structure of an electron injection layer EIL or an electron transport layer ETL, or may have a single-layer structure formed of an electron injection material and an electron transport material. In some embodiments, the electron transport region ETR may have a single-layer structure formed of a plurality of different materials, or may have a structure in which an electron transport layer ETL / electron injection layer EIL or a hole blocking layer HBL / electron transport layer ETL / electron injection layer EIL are stacked in order from the emission layer EML, but the embodiments of the present disclosure are not limited thereto. The thickness of the electron transport region ETR may be, for example, about to approximately

[0180] The electron transport region ETR may be formed using any suitable method such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, laser induced thermal imaging (LITI), etc.

[0181] When the electron transport region ETR includes an electron transport layer ETL, the electron transport region ETR may include an anthracene compound. However, the embodiment is not limited thereto, and the electron transport region ETR may include, for example, tris(8-hydroxyquinoline)aluminum (Alq3), 1,3,5-tris[(3-pyridyl)phenyl-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), bis(2-methyl-8-hydroxyquinolinolato-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), bis(benzoquinolinolato-10-hydroxy)beryllium (Bebq2), 9,10-di(naphthalene-2-yl)anthracene (ADN), or a mixture thereof. The thickness of the electron transport layer ETL may be about 1000 nm. to approximately For example, approximately to approximately When the thickness of the electron transport layer ETL satisfies the above range, satisfactory electron transport characteristics may be obtained without significantly increasing driving voltage.

[0182] When the electron transport region ETR includes an electron injection layer EIL, the electron transport region ETR can be formed using a metal halide (such as LiF, NaCl, CsF, RbCl and / or RbI), a lanthanide metal (such as ytterbium (Yb)), a metal oxide (such as Li2O and / or BaO) or 8-hydroxyquinoline lithium (LiQ), etc., but the embodiments of the present disclosure are not limited thereto. The electron injection layer EIL can also be formed from a mixture of an electron injection material and an insulating organic metal salt. The organic metal salt can be a material having an energy band gap of about 4 eV or greater. In some embodiments, the organic metal salt can include, for example, a metal acetate, a metal benzoate, a metal acetoacetate, a metal acetylacetonate and / or a metal stearate. The thickness of the electron injection layer EIL can be about 100 Å. to approximately or approximately to approximately When the thickness of the electron injection layer EIL satisfies the above range, satisfactory electron injection properties can be obtained without significantly increasing driving voltage.

[0183] As described above, the electron transport region ETR may include a hole blocking layer HBL. The hole blocking layer HBL may include, but is not limited to, at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), and 4,7-diphenyl-1,10-phenanthroline (Bphen).

[0184] The second electrode EL2 is disposed on the electron transport region ETR. The second electrode EL2 may be a common electrode or a negative electrode. The second electrode EL2 may be a transmissive electrode, a transflective electrode, or a reflective electrode. When the second electrode EL2 is a transmissive electrode, the second electrode EL2 may be formed of a transparent metal oxide (e.g., ITO, IZO, ZnO, ITZO, etc.).

[0185] When the second electrode EL2 is a transflective electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Zn, Sn, compounds thereof, mixtures thereof (e.g., a mixture of Ag and Mg), or oxides thereof (e.g., ITO, IZO). In some embodiments, the second electrode EL2 may have a multilayer structure including a reflective layer or a transflective layer formed of the above materials and a transparent conductive layer formed of ITO, IZO, ZnO, ITZO, or the like.

[0186] In some embodiments, the second electrode EL2 may be connected to the auxiliary electrode. When the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0187] Reference Figure 4 The organic electroluminescent device 10 according to the embodiment may further include a capping layer CPL on the second electrode EL2. The capping layer CPL may include, for example, α-NPD, NPB, TPD, m-MTDATA, Alq3, CuPc, N4,N4,N4',N4'-tetrakis(biphenyl-4-yl)biphenyl-4,4'-diamine (TPD15), 4,4',4"-tris(carbazol-9-yl)triphenylamine (TCTA), and the like.

[0188] The organic electroluminescent device 10 according to an embodiment of the present disclosure may include the nitrogen-containing compound represented by Formula 1 as described above, thereby exhibiting excellent luminous efficiency characteristics and long service life characteristics. In addition, the organic electroluminescent device 10 of the embodiment can achieve high efficiency characteristics and / or long service life characteristics in the blue wavelength region.

[0189] Hereinafter, the nitrogen-containing compound according to the embodiment of the present disclosure and the organic electroluminescent device of the embodiment will be described in more detail with reference to examples and comparative examples. The examples shown below are only illustrative for understanding the present disclosure, and the scope of the present disclosure is not limited thereto.

[0190] Example

[0191] Synthesis of nitrogen-containing compounds

[0192] In the following description, an example synthesis method of a nitrogen-containing compound is provided, but the synthesis method of the nitrogen-containing compound according to an embodiment of the present disclosure is not limited thereto.

[0193] 1. Synthesis of Compound 1

[0194] Synthesis of intermediate A

[0195]

[0196] 1- (2,4- difluorophenyl) -3,5- diphenyltriazine (2.0 g), 5,10- diphenyl -15- hydrogen -5H- diindole and [3,2-a: 3 ', 2 '-c] carbazole (2.9 g) and Cs2CO3 (3.8 g) were added to a 300 mL three-necked flask and replaced with an Ar atmosphere. Then, 120 mL of dehydrated DMF was added thereto, and the reactants were heated and stirred at 120 ° C for 4 hours. The resulting reaction solution was quenched with water, and the organic layer was extracted with dichloromethane, dried over anhydrous MgSO4, concentrated with an evaporator, and recrystallized with toluene and ethanol to obtain a light yellow solid (3.5 g, 74% yield). In FAB-MS measurement, the resulting solid had a molecular weight of 823 m / z, and therefore, it was confirmed that intermediate A was obtained.

[0197] Synthesis of compound 1

[0198]

[0199] Intermediate A (3.0 g) and carbazole (0.6 g) were used instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine and 5,10-diphenyl-15-hydro-5H-diindolo[3,2-a:3',2'-c]carbazole to perform the synthesis sequence of Intermediate A, thereby obtaining a pale yellow solid (2.4 g, 68% yield). In FAB-MS measurement, the obtained solid had a molecular weight of 970 m / z, thus confirming that Compound 1 was obtained.

[0200] 2. Synthesis of compound 3

[0201] Synthesis of intermediate B

[0202]

[0203] The synthesis sequence of Intermediate A was performed using 1-(2,5-difluorophenyl)-3,5-diphenyltriazine (3.0 g) and carbazole (1.5 g) instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine and 5,10-diphenyl-15-hydro-5H-diindolo[3,2-a:3',2'-c]carbazole to obtain a pale yellow solid (4.4 g, 62% yield). In FAB-MS measurement, the obtained solid had a molecular weight of 493 m / z, thus confirming that Intermediate B was obtained.

[0204] Synthesis of compound 3

[0205]

[0206] The synthetic sequence of Intermediate A was performed at 150° C. using Intermediate B (4.0 g) instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine to obtain a pale yellow solid (1.7 g, 22% yield). The obtained solid had a molecular weight of 970 m / z in FAB-MS measurement, thus confirming that Compound 3 was obtained.

[0207] 3. Synthesis of compound 4

[0208] Synthesis of intermediate C

[0209]

[0210] The synthesis sequence of Intermediate A was performed using 1-(3,5-difluorophenyl)-3,5-diphenyltriazine (3.0 g) and 3,6-diphenylcarbazole (2.8 g) instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine and 5,10-diphenyl-15-hydro-5H-diindolo[3,2-a:3',2'-c]carbazole to obtain a pale yellow solid (4.6 g, 83% yield). The obtained solid had a molecular weight of 645 m / z in FAB-MS measurement, thus confirming that Intermediate C was obtained.

[0211] Synthesis of compound 4

[0212]

[0213] Intermediate C (4.0 g) was used instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine to perform the synthesis sequence of Intermediate A, thereby obtaining a pale yellow solid (4.0 g, yield 77%). In FAB-MS measurement, the obtained solid had a molecular weight of 1120 m / z, thus confirming that Compound 4 was obtained.

[0214] 4. Synthesis of Compound 5

[0215] Synthesis of intermediate D

[0216]

[0217] The synthesis sequence of Intermediate A was performed using carbazole (1.5 g) instead of 5,10-diphenyl-15-hydro-5H-diindolo[3,2-a:3',2'-c]carbazole to obtain a pale yellow solid (4.6 g, 80% yield). The obtained solid had a molecular weight of 493 m / z in FAB-MS measurement, thus confirming that Intermediate D was obtained.

[0218] Synthesis of compound 5

[0219]

[0220] The synthetic sequence of Intermediate A was performed at 170° C. using Intermediate D (4.0 g) instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine to obtain a pale yellow solid (1.3 g, 17% yield). The obtained solid had a molecular weight of 970 m / z in FAB-MS measurement, thus confirming that Compound 5 was obtained.

[0221] 5. Synthesis of Compound 8

[0222] Synthesis of intermediate E

[0223]

[0224] The synthesis sequence of Intermediate A was performed using 1-(3,4-difluorophenyl)-3,5-diphenyltriazine (3.0 g) instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine to obtain a pale yellow solid (5.9 g, 82% yield). In FAB-MS measurement, the obtained solid had a molecular weight of 823 m / z, thus confirming that Intermediate E was obtained.

[0225] Synthesis of compound 8

[0226]

[0227] Intermediate E (5.0 g) and carbazole (1.0 g) were used instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine and 5,10-diphenyl-15-hydro-5H-diindolo[3,2-a:3',2'-c]carbazole to perform the synthesis sequence of Intermediate A, thereby obtaining a pale yellow solid (4.1 g, 70% yield). In FAB-MS measurement, the obtained solid had a molecular weight of 970 m / z, thus confirming that Compound 8 was obtained.

[0228] 6. Synthesis of Compound 9

[0229] Synthesis of intermediate F

[0230]

[0231] The synthesis sequence of Intermediate A was performed using 1-(2,5-difluorophenyl)-3,5-diphenyltriazine (4.0 g) instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine to obtain a pale yellow solid (6.8 g, 71% yield). In FAB-MS measurement, the obtained solid had a molecular weight of 823 m / z, thus confirming that Intermediate F was obtained.

[0232] Synthesis of compound 9

[0233]

[0234] The synthetic sequence of Intermediate A was performed using Intermediate F (6.0 g) and carbazole (1.2 g) instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine and 5,10-diphenyl-15-hydro-5H-diindolo[3,2-a:3',2'-c]carbazole to obtain a pale yellow solid (5.0 g, 70% yield). The obtained solid had a molecular weight of 970 m / z in FAB-MS measurement, thus confirming that Compound 9 was obtained.

[0235] 7. Synthesis of Compound 13

[0236] Synthesis of intermediate G

[0237]

[0238] The synthesis sequence of Intermediate A was performed using 1-(2,3-difluorophenyl)-3,5-diphenyltriazine (4.0 g) instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine to obtain a pale yellow solid (6.4 g, 68% yield). In FAB-MS measurement, the obtained solid had a molecular weight of 823 m / z, thus confirming that Intermediate G was obtained.

[0239] Synthesis of compound 13

[0240]

[0241] The synthetic sequence of Intermediate A was performed using Intermediate G (6.0 g) and carbazole (1.2 g) instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine and 5,10-diphenyl-15-hydro-5H-diindolo[3,2-a:3',2'-c]carbazole to obtain a pale yellow solid (5.7 g, 80% yield). The obtained solid had a molecular weight of 970 m / z in FAB-MS measurement, thus confirming that Compound 13 was obtained.

[0242] 8. Synthesis of Compound 14

[0243] Synthesis of intermediate H

[0244]

[0245] The synthesis sequence of Intermediate A was performed using 1-(2,6-difluorophenyl)-3,5-diphenyltriazine (4.0 g) instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine to obtain a pale yellow solid (6.7 g, 70% yield). In FAB-MS measurement, the obtained solid had a molecular weight of 823 m / z, thus confirming that Intermediate H was obtained.

[0246] Synthesis of compound 14

[0247]

[0248] Intermediate H (6.0 g) and carbazole (1.2 g) were used instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine and 5,10-diphenyl-15-hydro-5H-diindolo[3,2-a:3',2'-c]carbazole to perform the synthesis sequence of Intermediate A, thereby obtaining a pale yellow solid (0.9 g, 13% yield). In FAB-MS measurement, the obtained solid had a molecular weight of 970 m / z, thus confirming that Compound 14 was obtained.

[0249] 9. Synthesis of Compound 16

[0250] Synthesis of intermediate J

[0251]

[0252] The synthesis sequence of Intermediate A was performed using 1-(3,4-difluorophenyl)-3,5-diphenyltriazine (2.0 g) and carbazole (1.0 g) instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine and 5,10-diphenyl-15-hydro-5H-diindolo[3,2-a:3',2'-c]carbazole to obtain a pale yellow solid (2.2 g, 76% yield). The obtained solid had a molecular weight of 493 m / z in FAB-MS measurement, thus confirming that Intermediate J was obtained.

[0253] Synthesis of compound 16

[0254]

[0255] Intermediate J (2.0 g) was used instead of 1-(2,4-difluorophenyl)-3,5-diphenyltriazine to perform the synthesis sequence of Intermediate A, thereby obtaining a pale yellow solid (2.6 g, 65% yield). In FAB-MS measurement, the obtained solid had a molecular weight of 970 m / z, thus confirming that Compound 16 was obtained.

[0256] Fabrication of organic electroluminescent devices

[0257] The organic electroluminescent devices according to Examples 1 to 10 were manufactured using the above compounds as emission layer materials:

[0258] Example compounds

[0259]

[0260] Organic electroluminescent devices according to Comparative Examples 1 to 5 were manufactured using the comparative example compounds as emission layer materials:

[0261] Comparative Example Compounds

[0262]

[0263] The fluorescence properties of the example compounds and comparative example compounds were evaluated. The room temperature and 77K emission spectra of a mixed film prepared with a thickness of 50 nm and containing 18% of a fluorescent material in DPEPO were evaluated using a JASCO V-670 spectrometer. The T1 energy level was calculated from the emission spectrum and the ΔE was used to calculate the fluorescence intensity. ST The fluorescence lifetime was measured by Hamamatsu Photonics Quantaurus-Tau to evaluate the delayed fluorescence lifetime.

[0264] Table 1

[0265]

[0266]

[0267] Referring to the results in Table 1, all the exemplary compounds showed a small ΔE of at most 0.1 ST value and a delayed fluorescence lifetime of at most 5.2 μs, and thus can be appropriately or suitably used as a thermally activated delayed fluorescence material, but the comparative example compound exhibits a relatively large ΔE ST values ​​and a delayed fluorescence lifetime of at least 5.4 μs, and is therefore not considered suitable for thermally activated delayed fluorescence materials.

[0268] The organic electroluminescent devices of Examples and Comparative Examples were manufactured by the following method.

[0269] On a glass substrate with approximately The ITO was patterned with a thickness of 1000 nm, cleaned with ultrapure water, and UV / ozone treated for about 10 minutes. Thereafter, HAT-CN was deposited as The thickness of α-NPD was deposited as The thickness of mCP is deposited as to form a hole transport region.

[0270] Next, when forming the emission layer, the nitrogen-containing compound of the example or the comparative example compound and DPEPO were co-deposited at a weight ratio of 18:82 to form Thick layer.

[0271] TPBi is formed on the emission layer Thick layer, formed with LiF Then, a layer of about The thickness of the second electrode is .

[0272] In the examples and comparative examples, a vacuum deposition apparatus was used to form the hole transport region, the emission layer, the electron transport region, and the second electrode.

[0273] Evaluation of organic electroluminescent device characteristics

[0274] In order to evaluate the characteristics of the organic electroluminescent devices according to the examples and comparative examples, 1000 cd / m 2 The maximum emission wavelength (nm) and maximum external quantum yield (external quantum efficiency) (%) at the brightness.

[0275] Table 2

[0276]

[0277]

[0278] Referring to the results of Table 2, when the nitrogen-containing compound according to the example was included in the emission layer, it was confirmed that the luminous efficiency of the device was improved by increasing the external quantum yield compared with the comparative example.

[0279] Without being bound by any theory or explanation, it is believed that because the exemplary compounds all include multiple electron-donating substituents of different kinds, the rate constant of reverse-intersystem crossing (RISC) through higher-order triplet states is increased, thereby improving the luminous efficiency of the device.

[0280] In comparison, (for example, compared with examples including different types of electron-donating groups), although Comparative Examples 1 and 4 include compounds substituted with multiple electron-donating carbazole groups having the same structure, good device luminescence efficiency is not exhibited. It is confirmed that although Comparative Example 2 includes a compound substituted with (for example, a single) triazatriazol (or "triazatriazol") group, it does not exhibit the same high-efficiency luminescence as the nitrogen-containing compound of the present disclosure. Comparative Example 3 includes a compound substituted with multiple electron-withdrawing substituents (for example, triazine groups), which greatly improves the delayed fluorescence lifetime, resulting in degradation of the device luminescence efficiency. In Comparative Example 5, although multiple electron-donating groups are combined, the delayed fluorescence lifetime is greatly improved, resulting in degradation of the device luminescence efficiency.

[0281] The exemplary organic electroluminescent device may improve the lifetime of the device by using the nitrogen-containing compound represented by Formula 1 as an emission layer material.

[0282] The organic electroluminescent device according to the embodiment of the present disclosure can achieve high efficiency and long service life.

[0283] The nitrogen-containing compound according to an embodiment of the present disclosure may improve the efficiency and lifespan of an organic electroluminescent device.

[0284] Although the present disclosure has been described with reference to various embodiments, it will be understood that the present disclosure should not be limited to these embodiments, but various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the present disclosure.

[0285] Therefore, the technical scope of the present disclosure is not intended to be limited to the contents set forth in the detailed description of the specification, but is intended to be defined by the claims and their equivalents.

Claims

1. An organic electroluminescent device, comprising: a first electrode; a hole transport region, located on the first electrode; an emission layer, located on the hole transport region; an electron transport region, located on the emission layer; as well as a second electrode, located on the electron transport region, The first electrode and the second electrode each independently include at least one selected from the following materials: Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn and Zn; Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn and Zn; n; a compound of two or more of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn, and Zn; and an oxide of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn, and Zn, and Wherein, the emission layer includes a nitrogen-containing compound represented by Formula 1: Formula 1 In formula 1, Ar1 and Ar2 are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for ring formation or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for ring formation, and A1 to A5 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, or A1 to A5 are each independently represented by Formula 2 or Formula 3, At least one of A1 to A5 is represented by Formula 2, and at least another one of A1 to A5 is represented by Formula 3: Formula 2 Formula 3 Among them, in formula 2 and formula 3, Ar3 and Ar4 are each independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, R1 to R5 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted thiol group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, and R1 to R5 are optionally bonded to an adjacent ring to form a ring, and a to e are each independently an integer from 0 to 4.

2. The organic electroluminescent device according to claim 1, wherein Formula 1 is expressed by any one of Formulas 4-1 to 4-4: Formula 4-1 Formula 4-2 Formula 4-3 Formula 4-4 Among them, in formula 4-1 to formula 4-4, Ar1 to Ar4, A1 to A4, R1 to R5 and a to e are independently the same as defined in Formulae 1 to 3.

3. The organic electroluminescent device according to claim 1, wherein Formula 1 is expressed by any one of Formulas 5-1 to 5-4: Formula 5-1 Formula 5-2 Formula 5-3 Formula 5-4 Among them, in formula 5-1 to formula 5-4, Ar1 to Ar4, A1 to A3, A5, R1 to R5 and a to e are independently the same as defined in Formulae 1 to 3.

4. The organic electroluminescent device according to claim 1, wherein Formula 1 is expressed by Formula 6-1 or Formula 6-2: Formula 6-1 Formula 6-2 Among them, in formula 6-1 and formula 6-2, Ar1 to Ar4, A1, A2, A4, A5, R1 to R5 and a to e are independently the same as defined in Formulae 1 to 3.

5. The organic electroluminescent device according to claim 1, wherein When a is an integer of 2 or greater, a pair of adjacent R1s forms a condensed ring structure according to any one of Formula 7-1 to Formula 7-4: Among them, in formula 7-1 to formula 7-4, R a to R g are independently a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted thiol group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, and j to m are each independently an integer from 0 to 4. The organic electroluminescent device according to claim 1 , wherein: Ar1 to Ar4 are each independently represented by Formula 8: Formula 8 In formula 8, Y1 to Y5 are each independently CX or N, and X is a hydrogen atom, a deuterium atom, an alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and X is optionally bonded to an adjacent ring to form a ring.

7. The organic electroluminescent device according to claim 1, wherein The nitrogen-containing compound represented by Formula 1 is any one of the compounds represented by Compound Group 1: Compound Group 1 8. A nitrogen-containing compound, wherein the nitrogen-containing compound is represented by Formula 1: Formula 1 in, In formula 1, Ar1 and Ar2 are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for ring formation or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for ring formation, and A1 to A5 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, or A1 to A5 are each independently represented by Formula 2 or Formula 3, At least one of A1 to A5 is represented by Formula 2, and at least another one of A1 to A5 is represented by Formula 3: Formula 2 Formula 3 Among them, in formula 2 and formula 3, Ar3 and Ar4 are each independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, R1 to R5 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted thiol group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, and R1 to R5 are optionally bonded to an adjacent ring to form a ring, and a to e are each independently an integer from 0 to 4.

9. The nitrogen-containing compound according to claim 8, wherein Formula 1 is expressed by any one of Formulas 4-1 to 4-4: Formula 4-1 Formula 4-2 Formula 4-3 Formula 4-4 Among them, in formula 4-1 to formula 4-4, Ar1 to Ar4, A1 to A4, R1 to R5 and a to e are independently the same as defined in Formulae 1 to 3.

10. The nitrogen-containing compound according to claim 8, wherein Formula 1 is expressed by any one of Formulas 5-1 to 5-4: Formula 5-1 Formula 5-2 Formula 5-3 Formula 5-4 Among them, in formula 5-1 to formula 5-4, Ar1 to Ar4, A1 to A3, A5, R1 to R5 and a to e are independently the same as defined in Formulae 1 to 3.

11. The nitrogen-containing compound according to claim 8, wherein Formula 1 is expressed by Formula 6-1 or Formula 6-2: Formula 6-1 Formula 6-2 Among them, in formula 6-1 and formula 6-2, Ar1 to Ar4, A1, A2, A4, A5, R1 to R5 and a to e are independently the same as defined in Formulae 1 to 3.

12. The nitrogen-containing compound according to claim 8, wherein When a is an integer of 2 or greater, a pair of adjacent R1s forms a condensed ring structure according to any one of Formula 7-1 to Formula 7-4: Among them, in formula 7-1 to formula 7-4, R a to R g are independently a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted thiol group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, and j to m are each independently an integer from 0 to 4.

13. The nitrogen-containing compound according to claim 8, wherein The nitrogen-containing compound represented by Formula 1 is any one of the compounds represented by Compound Group 1: Compound Group 1

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