Organic electroluminescence device and compound for organic electroluminescence device

Abstract

Disclosed are an organic electroluminescent device and a compound for an organic electroluminescent device. The organic electroluminescent device of an embodiment includes a first electrode, a second electrode, and an emission layer between the first electrode and the second electrode, wherein the emission layer includes a compound represented by Formula 1, thereby showing excellent emission efficiency properties and long lifetime characteristics: Formula 1

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2019-0121047, filed on September 30, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] One or more aspects of embodiments of this disclosure relate herein to organic electroluminescent devices and compounds used therein, and more particularly to compounds used as luminescent materials and organic electroluminescent devices comprising the same. Background Technology

[0004] Recently, there has been active development of organic electroluminescent displays (OLEDs) as image displays. Unlike liquid crystal displays (LCDs), OLEDs are self-emissive displays in which holes and electrons injected from a first electrode and a second electrode recombine in an emitting layer, and the emitting layer contains a light-emitting material containing organic compounds to emit light to achieve image display.

[0005] When applying organic electroluminescent devices to displays, there is a demand (or expectation) for a reduction in the driving voltage of the organic electroluminescent devices as well as an increase in emission efficiency and lifetime, and there is an ongoing search for the development of materials for organic electroluminescent devices that can stably (or appropriately) achieve these properties.

[0006] In particular, recently, in order to realize highly efficient organic electroluminescent devices, techniques for phosphorescence emission using triplet energy or delayed fluorescence emission using the phenomenon of generating singlet excitons through collisions of triplet excitons (triplet-triplet annihilation, TTA) are being developed, and materials for thermally activated delayed fluorescence (TADF) using the delayed fluorescence phenomenon are being developed. Summary of the Invention

[0007] One or more aspects of embodiments of this disclosure relate to organic electroluminescent devices that exhibit superior (or improved) emission efficiency and long lifetime characteristics.

[0008] One or more aspects of the embodiments of this disclosure also relate to compounds as materials for organic electroluminescent devices having superior (or improved) emission efficiency and long lifetime characteristics.

[0009] According to an embodiment, a compound represented by the following formula 1 is provided:

[0010] Formula 1

[0011]

[0012] In Formula 1, X1to X4may each independently be CR a , L can be a substituted or unsubstituted polyvalent aryl group of 6 to 30 carbon atoms for forming a ring or a substituted or unsubstituted polyvalent heteroaryl group of 2 to 30 carbon atoms for forming a ring, and "n" can be 1 or 2. Ar can be a substituted or unsubstituted hydrocarbon ring group of 6 to 30 carbon atoms for forming a ring or a substituted or unsubstituted heterocyclic ring group of 2 to 30 carbon atoms for forming a ring, and R a may be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 30 carbon atoms for forming a ring, and / or combined with an adjacent group to form a ring.

[0013] In an embodiment, Formula 1 can be represented by the following Formula 1-1:

[0014] Formula 1-1

[0015]

[0016] In Formula 1-1, L, "n", and Ar are the same as defined in Formula 1.

[0017] In an embodiment, Ar can be an unsubstituted aryl group of 6 to 20 carbon atoms for forming a ring or a substituted or unsubstituted heteroaryl group of 2 to 20 carbon atoms for forming a ring, the heteroaryl group including at least one selected from N, O, and B as a ring-forming atom.

[0018] In an embodiment, Ar can be represented by the following Formula 2:

[0019] Formula 2

[0020]

[0021] In Formula 2, Y can be N or B, Z can be a direct bond, O, S, NR d or CR e R f , and "b" and "c" can each independently be an integer selected from 0 to 4. R b to R f may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 30 carbon atoms for forming a ring, and / or combined with an adjacent group to form a ring. denotes a bonding position.

[0022] In an embodiment, Formula 2 can be represented by Formula 2-1 or Formula 2-2 below:

[0023] Formula 2-1

[0024]

[0025] Formula 2-2

[0026]

[0027] In Formula 2-1 and Formula 2-2, Z, R b , R c , "b" and "c" are the same as defined in Formula 2.

[0028] In an embodiment, Formula 2-2 can be represented by any one of Formula 2-2A to Formula 2-2E below:

[0029] Formula 2-2A

[0030]

[0031] Formula 2-2B

[0032]

[0033] Formula 2-2C

[0034]

[0035] Formula 2-2D

[0036]

[0037] Formula 2-2E

[0038]

[0039] In Formula 2-2E, "b1" can be an integer selected from 0 to 3, "b2" can be an integer selected from 0 to 4, and R b1 and R b2 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 30 carbon atoms for forming a ring, and / or combined with an adjacent group to form a ring. In Formula 2-2A to Formula 2-2E, R b , R c , "b" and "c" are the same as defined in Formula 2.

[0040] In an embodiment, the compound represented by Formula 1 can be a green dopant which emits green light having a center wavelength of about 500 nm to about 550 nm.

[0041] In an embodiment, the compound represented by Formula 1 can be a blue dopant which emits blue light having a center wavelength of about 420 nm to about 470 nm.

[0042] In an embodiment, the compound represented by Formula 1 can have an absolute value of a difference between a lowest excited singlet energy level (S1) and a lowest excited triplet energy level (T1) (ΔE ST ) of about 0.2 eV or less.

[0043] According to an embodiment of the present disclosure, there is provided an organic electroluminescent device including a first electrode; a second electrode on the first electrode; and an emission layer between the first electrode and the second electrode and including the above compound of the embodiment. In the compound, L can be a substituted or unsubstituted phenylene or a substituted or unsubstituted pyridylene.

[0044] In an embodiment, the emission layer can include a host and a dopant, and the host can include the compound of the embodiment.

[0045] In an embodiment, the emission layer can emit delayed fluorescence, and the compound can be a delayed fluorescence dopant.

[0046] In an embodiment, the emission layer can emit light having a center wavelength of about 500 nm to about 550 nm, or emit light having a center wavelength of about 420 nm to about 470 nm. BRIEF DESCRIPTION OF DRAWINGS

[0047] 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 drawings illustrate the example embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. In the drawings:

[0048] FIG. 1 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure;

[0049] FIG. 2 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure;

[0050] FIG. 3 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure; and

[0051] FIG. 4 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0052] The present disclosure can have various modifications and can be implemented in different forms, and exemplary embodiments will be explained in more detail with reference to the accompanying drawings. However, the present disclosure can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, all modifications, equivalents, and substitutes included in the spirit and technical scope of the present disclosure should be included in the present disclosure.

[0053] It will be understood that when an element (or a region, layer, component, etc.) is referred to as being "on", "connected to", or "coupled to" another element (or a region, layer, component, etc.), it can be directly on, connected or coupled to the other element (with no intervening elements therebetween) or one or more third elements can be present therebetween.

[0054] Throughout the specification and the drawings, like reference numerals refer to like elements. Furthermore, in the drawings, the thickness, proportions, and dimensions of constituting elements are exaggerated for the sake of effective explanation of the technology.

[0055] The term "and / or" includes one or more combinations of the elements connected by the term. Expressions such as "at least one of", "one", and "selected from" modify the entire list of elements that follows the term and do not modify the individual elements of the list. In addition, the use of "may" in describing the embodiments of the present disclosure indicates "one or more embodiments of the present disclosure".

[0056] It will be understood that, although the terms first, second, etc. can 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. Thus, a first element could be termed a second element without departing from the teachings of the present disclosure. Similarly, a second element could be termed a first element. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0057] In addition, the terms "below", "under", "above", and "on" are used to explain the relationship of elements shown in the drawings. These terms refer to relative concepts and will be explained based on the direction shown in the drawings.

[0058] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this present disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0059] It will be further understood that the terms "comprises" and / or "comprising", when used in this specification, specify the presence of stated features, integers, steps, actions, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, actions, operations, elements, components, or combinations thereof.

[0060] Hereinafter, organic electroluminescent devices according to embodiments of the present disclosure and compounds included therein will be explained with reference to the attached drawings.

[0061] FIG. 1 to FIG. 4 To schematically show a cross-sectional view of an organic electroluminescent device according to an example embodiment of the present disclosure. Referring to FIG. 1 to FIG. 4 In the organic electroluminescent device 10 of the embodiments, a first electrode EL1 and a second electrode EL2 are placed opposite to each other, and between the first electrode EL1 and the second electrode EL2, an emission layer EML can be provided.

[0062] Further, the organic electroluminescent device 10 of the embodiments further includes, in addition to the emission layer EML, a plurality of functional layers between the first electrode EL1 and the second electrode EL2. The plurality of functional layers can include a hole transport region HTR and an electron transport region ETR. For example, the organic electroluminescent device 10 according to the embodiments can include a first electrode EL1, a hole transport region HTR, an emission layer EML, an electron transport region ETR, and a second electrode EL2, which are stacked in this order. Further, the organic electroluminescent device 10 of the embodiments can include a capping layer CPL on the second electrode EL2.

[0063] The organic electroluminescent device 10 of the embodiments can include a compound of the embodiments, which will be explained in more detail herein below, in the emission layer EML located between the first electrode EL1 and the second electrode EL2. However, the embodiments of the present disclosure are not limited thereto, and the organic electroluminescent device 10 of the embodiments can include a compound according to the embodiments in the hole transport region HTR or the electron transport region ETR included in the plurality of functional layers between the first electrode EL1 and the second electrode EL2.

[0064] Meanwhile, when compared with FIG. 1 , FIG. 2 A cross-sectional view of the organic electroluminescent device 10 of the embodiments is shown, 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. Further, when compared with FIG. 1 , FIG. 3A cross-sectional view of the organic electroluminescent device 10 of an embodiment is shown, 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. When compared to FIG. 2 FIG. 4 A cross-sectional view of the organic electroluminescent device 10 of an embodiment is shown, 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. When compared to

[0065] The first electrode EL1 has electrical conductivity. The first electrode EL1 can be formed using a metal alloy or any suitable electrically conductive compound. The first electrode EL1 can be an anode. In some embodiments, the first electrode EL1 can be a pixel electrode. The first electrode EL1 can be a transmissive electrode, a transreflective electrode, or a reflective electrode. If the first electrode EL1 is a transmissive electrode, the first electrode EL1 can 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). If the first electrode EL1 is a transreflective electrode or a reflective electrode, the first electrode EL1 can include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, or Ti, or a compound thereof, or a mixture thereof (e.g., a mixture of Ag and Mg). In some embodiments, the first electrode EL1 can have a structure including multiple layers, which includes a reflective layer or a transreflective layer formed using any of the above materials and a transmissive conductive layer formed using ITO, IZO, ZnO, and / or ITZO. For example, the first electrode EL1 can include a three-layer structure of ITO / Ag / ITO. However, embodiments of the present disclosure are not limited thereto. The thickness of the first electrode EL1 can be about 10 nm to about 1,000 nm, about 50 nm to about 500 nm, or about 100 nm to about 300 nm. to about 1,000 nm, about 50 nm to about 500 nm, or about 100 nm to about 300 nm. For example, about 10 nm to about 1,000 nm, about 50 nm to about 500 nm, or about 100 nm to about 300 nm. to about 1,000 nm, about 50 nm to about 500 nm, or about 100 nm to about 300 nm.

[0066] The hole transport region HTR can be provided on the first electrode EL1. The hole transport region HTR can 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. The thickness of the hole transport region HTR can be about 10 nm to about 1,000 nm, about 50 nm to about 500 nm, or about 100 nm to about 300 nm. to about 1,000 nm, about 50 nm to about 500 nm, or about 100 nm to about 300 nm.

[0067] The hole transport region HTR can have a single layer formed using a single material, a single layer formed using a plurality of different materials, or a multi-layer structure including a plurality of layers formed using a plurality of different materials.

[0068] ​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 it may have a single-layer structure formed using a hole injection material and a hole transport material. In some embodiments, the hole transport region HTR may have a single-layer structure formed using a variety of different materials, or a structure consisting of 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 stacked from the first electrode EL1, without limitation.

[0069] Hole transport regions (HTRs) can be formed using one or more suitable methods, such as vacuum deposition, spin coating, casting, Langmuir-Brookett (LB) method, inkjet printing, laser printing and / or laser-induced thermal imaging (LITI).

[0070] Hole injection layer HIL may include, for example, phthalocyanine compounds (such as copper phthalocyanine), N 1 N 1 '-([1,1'-biphenyl]-4,4'-diyl)bis(N 1 -Phenyl-N 4 N 4 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) (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PA) NI / DBSA), polyaniline / camphor sulfonic acid (PANI / CSA), polyaniline / poly(4-styrene sulfonate) (PANI / PSS), N,N'-bis(1-naphth-1-yl)-N,N'-diphenyl-benzidine (NPB), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium [tetra(pentafluorophenyl)borate] and / or dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexaonitrile (HAT-CN).

[0071] Hole transport layers (HTLs) may include, for example, carbazole derivatives (such as N-phenylcarbazole and / or polyvinylcarbazole), fluorenyl 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'-bis(1-naphth-1-yl)-N,N'-diphenyl-biphenylamine (NPB), 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.

[0072] The thickness of the hole transport region (HTR) can be approximately to approximately For example, about to approximately The thickness of the hole injection layer HIL can be, for example, approximately to approximately Furthermore, the thickness of the hole transport layer (HTL) can be approximately [missing information]. to approximately For example, the thickness of the electron blocking layer (EBL) can be approximately [missing information]. to approximately When the thicknesses of the hole transport region HTR, hole injection layer HIL, hole transport layer HTL, and electron blocking layer EBL each independently satisfy any of the above ranges, satisfactory (or appropriate) hole transport properties can be achieved without a significant increase in driving voltage.

[0073] In addition to the materials described above, the hole transport region (HTR) may further include a charge-generating material to increase conductivity. The charge-generating material may be 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 quinone derivatives, metal oxides, and cyano-containing compounds, without limitation. Non-limiting examples of p-dops may include quinone derivatives (such as tetracyanoquinone dimethyl (TCNQ) and / or 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinone dimethyl (F4-TCNQ)), metal oxides (such as tungsten oxide and / or molybdenum oxide), and inorganic metal compounds (such as CuI and / or RbI), without limitation.

[0074] As described above, the hole transport region HTR can further include at least one of a hole buffer layer and an electron blocking layer EBL in addition to the hole injection layer HIL and the hole transport layer HTL. The hole buffer layer can compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer EML and can increase light emission efficiency. Any material that can be included in the hole transport region HTR can be used as a material included in the hole buffer layer. The electron blocking layer EBL is a layer that functions to prevent (or reduce) injection of electrons from the electron transport region ETR to the hole transport region HTR.

[0075] The emission layer EML can be provided on the hole transport region HTR. The emission layer EML can have, for example, a thickness of about 1 nm to about 5 nm. to about 5 nm. or about 5 nm. to about 5 nm. The emission layer EML can have a single layer formed using a single material, a single layer formed using a plurality of different materials, or a multi-layer structure having a plurality of layers formed using a plurality of different materials.

[0076] In the organic electroluminescent device 10 of the embodiments, the emission layer EML can include the compound of the embodiments.

[0077] Meanwhile, in the description, the term "substituted or unsubstituted" corresponds to an unsubstituted group or a group substituted with at least one substituent selected from the group consisting of a deuterium atom, a halogen atom, a cyano group, a nitro group, an amino group, a silyl group, an oxyl group, a sulfanyl group, a sulfinyl group, a sulfonyl group, a carbonyl group, a boryl group, a phosphine oxide group, a phosphine sulfide group, an alkyl group, an alkenyl group, an alkoxyl group, a hydrocarbyl group, an aryl group, and a heterocyclic group. The oxyl group can include an alkoxyl group and an aryloxyl group. The sulfanyl group can include an alkylthio group and an arylthio group. Furthermore, each of the exemplified substituents can be substituted or unsubstituted by itself. For example, a biphenyl group can be interpreted as an aryl group or a phenyl group substituted with a phenyl group.

[0078] In the description, the term "formed into a ring in combination with an adjacent group" can refer to formed into a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocyclic ring in combination with an adjacent group. The hydrocarbon ring includes an aliphatic hydrocarbon ring and an aromatic hydrocarbon ring. The heterocyclic ring includes an aliphatic heterocyclic ring and an aromatic heterocyclic ring. The ring formed in combination with the adjacent group can be a single ring or a polycyclic ring. In some embodiments, the ring formed in combination with the adjacent group can be combined with another ring to form a spiro structure.

[0079] In the description, the term "adjacent groups" can refer to a pair of substituents in which a first substituent is attached to an atom that is directly attached to another atom that is substituted by a second substituent; a pair of substituents that are attached to the same atom; or a pair of substituents in which the first substituent is spatially located closest to the second substituent. For example, in 1,2-dimethylbenzene, the two methyl groups can be interpreted as "adjacent groups" to each other, and in 1,1-diethylcyclopentane, the two ethyl groups can be interpreted as "adjacent groups" to each other.

[0080] In the description, examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0081] In the description, an alkyl group can be a straight chain, branched, or cyclic alkyl group. The number of carbons of an alkyl group can be 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of alkyl groups can include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, t-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl, 4-t-butylcyclohexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, t-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethyihexadecyl, 2-butyihexadecyl, 2-hexyihexadecyl, 2-octyihexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, 2-ethyleicosyl, 2-butyileicosyl, 2-hexyleicosyl, 2-octyleicosyl, n- heneicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, n-triacontyl, 2-ethytriacontyl, 2-butytriacontyl, 2-hexytriacontyl, 2-octytriacontyl, and the like, without limitation.

[0082] In the description, a hydrocarbon ring can be an aliphatic hydrocarbon ring or an aromatic hydrocarbon ring of 5 to 60, 5 to 30, or 5 to 20 carbon atoms used to form the ring. A hydrocarbon ring group can be a functional group or a substituent derived from an aliphatic hydrocarbon ring, or a functional group or a substituent derived from an aromatic hydrocarbon ring. The number of carbons used to form the ring of a hydrocarbon ring can be 5 to 60, 5 to 30, or 5 to 20.

[0083] In descriptions, aryl can refer to a functional group or substituent derived from an aromatic hydrocarbon ring. The aryl can be a monocyclic aryl or a polycyclic aryl. The number of carbons used to form the ring of the aryl can be 6 to 30, 6 to 20, or 6 to 15. Examples of aryl can include phenyl, naphthyl, fluorenyl, anthryl, phenanthryl, biphenyl, terphenyl, quaterphenyl, quinquephenyl, sexiphenyl, triphenylenyl, pyrenyl, benzofluorantenyl, 1,2- benzophenanthryl, and the like, without limitation.

[0084] In descriptions, heterocyclyl can refer to a functional group or substituent derived from a ring including one or more heteroatoms selected from B, O, N, P, Si, and S. Heterocyclyl includes aliphatic heterocyclyl and aromatic heterocyclyl. The aromatic heterocyclyl can be a heteroaryl. The aliphatic heterocycle (e.g., aliphatic heterocyclyl) and the aromatic heterocycle (e.g., aromatic heterocyclyl) can each independently be a monocyclic or a polycyclic.

[0085] In descriptions, heterocycle (e.g., heterocyclyl) can include one or more heteroatoms selected from B, O, N, P, Si, and S as a heteroatom. If the heterocycle includes two or more heteroatoms, the two or more heteroatoms can be the same or different. The heterocycle can be a monocyclic heterocycle or a polycyclic heterocycle and can include a heteroaryl. The number of carbons used to form the ring of the heterocycle can be 2 to 30, 2 to 20, or 2 to 10.

[0086] In descriptions, aliphatic heterocyclyl can include one or more heteroatoms selected from B, O, N, P, Si, and S as a heteroatom. The number of carbons used to form the ring of the aliphatic heterocyclyl can be 2 to 30, 2 to 20, or 2 to 10. Examples of aliphatic heterocyclyl include oxiranyl, thiranyl, pyrrolidinyl, piperidinyl, tetrahydrofuranyl, tetrahydrothiophenyl, thianyl, tetrahydropyranyl, 1,4-dioxanyl, and the like, without limitation.

[0087] In the description, the heteroaryl group can include one or more selected from B, O, N, P, Si, and S as a heteroatom. If the heteroaryl group includes two or more heteroatoms, the two or more heteroatoms can be the same or different. The heteroaryl group can be a monocyclic heteroaryl group or a polycyclic heteroaryl group. The number of carbons used to form a ring of the heteroaryl group can be 2 to 30, 2 to 20, or 2 to 10. Examples of the heteroaryl group can include thienyl, furanyl, pyrrolyl, imidazolyl, triazolyl, pyridyl, bipyridyl, pyrimidyl, triazinyl, acridinyl, pyridazinyl, pyrazinyl, quinolyl, quinazolyl, quinoxalyl, phenoxazinyl, phthalazinyl, pyridopyrimidyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolyl, indolyl, carbazolyl, N-arylcarbazolyl, N-heteroarylcarbazolyl, N-alkylcarbazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothienyl, dibenzothienyl, thienothienyl, benzofuranyl, phenanthrolinyl, thiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, thiadiazolyl, phenothiazinyl, dibenzothiophyl, dibenzofuranyl, and the like, without limitation.

[0088] In the description, the number of carbons of the amine group is not particularly limited, but can be 1 to 30. The amine group can include an alkylamine group and an arylamine group. Examples of the amine group include a methylamine group, a dimethylamine group, a phenylamine group, a diphenylamine group, a naphthylamine group, a 9-methyl-anthracenylamine group, and the like, without limitation. For example, the alkyl group in the alkylamine group can be the same as the alkyl group described above, and the aryl group in the arylamine group can be the same as the aryl group described above.

[0089] In the description, direct connection can refer to a single bond.

[0090] Meanwhile, in the description, may refer to a connection position (e.g., a bonding site with an adjacent atom).

[0091] In the description, "an atom for forming a ring" can refer to a ring-forming atom.

[0092] The organic electroluminescent device 10 of the embodiment can include a compound of the embodiment represented by the following Formula 1:

[0093] Formula 1

[0094]

[0095] In Formula 1, X1 to X4 can each independently be CR a .

[0096] That is, the compound of the embodiment represented by Formula 1 can include a fused ring structure of benzofuran and benzoxazole.

[0097] If X1 to X4 are CR a , the plurality of R aEach group may independently include a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amino group, an alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for ring formation, or a heteroaryl group with 2 to 30 carbon atoms for ring formation, and / or combine with adjacent groups to form a ring. For example, CR a R in a The aryl group may be a hydrogen atom, a 6 to 20 substituted or unsubstituted carbon atoms for forming a ring, or a heteroaryl group may be a substituted or unsubstituted carbon atom for forming a ring, but the embodiments disclosed herein are not limited thereto.

[0098] For example, if multiple CRs selected from X1 to X4 a This indicates that multiple Rs a They can be the same, or at least one of X1 to X4 can be different. Meanwhile, multiple R... a The neighboring R in a Groups can combine with each other to form hydrocarbon rings or heterocycles.

[0099] In Formula 1, L can be a polyvalent aryl group with 6 to 30 substituted or unsubstituted carbon atoms for forming the ring, or a polyvalent heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms for forming the ring.

[0100] L can be a substituted or unsubstituted phenylene group or a substituted or unsubstituted pyridylene group. For example, in Formula 1, L can be represented by L-1 or L-2:

[0101]

[0102] In the compounds of the embodiments represented by Formula 1, Ar can be a hydrocarbon cyclic group with 6 to 30 substituted or unsubstituted carbon atoms for forming the ring, or a heterocyclic group with 2 to 30 substituted or unsubstituted carbon atoms for forming the ring. For example, Ar can be an aryl group with 6 to 20 substituted or unsubstituted carbon atoms for forming the ring, or a heteroaryl group with 2 to 20 substituted or unsubstituted carbon atoms for forming the ring. Ar can be an unsubstituted aryl group with 6 to 20 substituted carbon atoms for forming the ring, or a heteroaryl group with 2 to 20 substituted carbon atoms for forming the ring, wherein the heteroaryl group includes at least one selected from N, O, and B as a cyclic atom.

[0103] In Formula 1, "n" can be 1 or 2. For example, in the compound of the embodiment represented by Formula 1, the Ar group bound to the linker L can be one or two (e.g., one or two Ar groups can be bound to L). Meanwhile, if "n" is 2, the two Ar groups bound to the linker can be the same or different.

[0104] The compound according to the embodiments can have a fused ring of a benzofuran and a benzoxazole connected to a substituted or unsubstituted hydrocarbon ring or heterocycle represented by "Ar" via a linker "L".

[0105] The fused portion of the present compound obtained by fusing a benzofuran and a benzoxazole can be an electron acceptor. In embodiments, the compound can have a D (electron donor) -A (electron acceptor) structure. In this case, in the compound represented by Formula 1, the "Ar" group can be an electron donor. In some embodiments, in the compound represented by Formula 1, if "n" is 2, the compound according to the embodiments can include one electron acceptor and two electron donors.

[0106] For example, if Ar is a substituted or unsubstituted aryl group, Ar can be a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenyl group, or a substituted or unsubstituted triphenylene group. However, embodiments of the present disclosure are not limited thereto.

[0107] In some embodiments, if Ar is a substituted or unsubstituted heteroaryl group, Ar can be a substituted or unsubstituted carbazolyl group or a substituted or unsubstituted dibenzofuranyl group. However, embodiments of the present disclosure are not limited thereto.

[0108] For example, Ar can be represented by the following Formula 2:

[0109] Formula 2

[0110]

[0111] In Formula 2, Y can be N or B, and Z can be a direct bond, O, S, NR d or CR e R f . In Formula 2, "b" and "c" can each independently be an integer selected from 0 to 4.

[0112] In Formula 2, R b to R f may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 30 carbon atoms for forming a ring, and / or combined with an adjacent group to form a ring.

[0113] If "b" is an integer of 2 or more, a plurality of R b may be the same, or at least one of a plurality of R b may be different. If "c" is an integer of 2 or more, a plurality of R c may be the same, or at least one of a plurality of Rc At least one of them may be different.

[0114] At the same time, if R b To R f If it combines with adjacent groups to form a ring, then it is selected from R. b To R f Adjacent substituents in Ar can combine with each other to form hydrocarbon rings or heterocycles. The rings formed by combining adjacent substituents can fuse with the hydrocarbon ring core or heterocycle core of Ar.

[0115] Ar, as expressed by Equation 2, can be expressed by Equation 2-1 or Equation 2-2 as follows:

[0116] Equation 2-1

[0117]

[0118] Equation 2-2

[0119]

[0120] In Equations 2-1 and 2-2, the conditions for Z and R provided by Equation 2 can be applied. b R c The same meaning for “b” and “c”.

[0121] Meanwhile, equation 2-2 can be represented by any one of the following equations 2-2A to 2-2E:

[0122] Formula 2-2A

[0123]

[0124] Formula 2-2B

[0125]

[0126] Formula 2-2C

[0127]

[0128] Equation 2-2D

[0129]

[0130] Formula 2-2E

[0131]

[0132] In Equation 2-2E, "b1" can be an integer selected from 0 to 3, and "b2" can be an integer selected from 0 to 4. Furthermore, R b1 and R b2each independently can be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 carbon atoms used for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 30 carbon atoms used for forming a ring, and / or combined with an adjacent group to form a ring.

[0133] In Formula 2-2A to Formula 2-2E, the same explanations for R b , R c , "b", and "c" provided in connection with Formula 2 can be applied.

[0134] In some embodiments, Formula 1 can be represented by the following Formula 1-1:

[0135] Formula 1-1

[0136]

[0137] In Formula 1-1, the same explanations for L, "n", and Ar provided in connection with Formula 1 can be applied.

[0138] In the compound of the embodiment represented by Formula 1, for example, if "Ar" is represented by Formula 2-2, the compound of the embodiment can be an emission delayed fluorescent material of a D-A type (or the like). The compound according to the embodiment can be an emission thermally activated delayed fluorescent (TADF) material of a D-A type (or the like) including a fused portion (e.g., a fused portion) in which benzofuran and benzoxazole are fused as an electron acceptor and a portion (e.g., a portion) represented by Formula 2-2 as an electron donor.

[0139] The compound of the embodiment can be any one of the compounds represented in the following Compound Group 1. The organic electroluminescent device 10 of the embodiment can include at least one of the compounds represented in Compound Group 1 in an emission layer EML.

[0140] Compound Group 1

[0141]

[0142]

[0143]

[0144] The compound according to the embodiment can be an emission thermally activated delayed fluorescent (TADF) material having an emission center wavelength (λ maxThe luminescent material is a light-emitting material. For example, the compound of the embodiment represented by Formula 1 may be a light-emitting material having a light-emitting center wavelength of about 420 nm to about 470 nm, or a light-emitting material having a light-emitting center wavelength of about 500 nm to about 550 nm. The compound of the embodiment represented by Formula 1 may be a blue dopant or a green dopant.

[0145] In the organic electroluminescent device 10 of the embodiment, the emitting layer EML includes a host and a dopant, and may include the compounds described above in the embodiment as dopant. For example, in the organic electroluminescent device 10 of the embodiment, the emitting layer EML may include the compounds described above in the embodiment as dopant for emitting delayed fluorescence.

[0146] The compound represented by Equation 1 has an absolute value (ΔE) between the lowest excited singlet level (S1) and the lowest excited triplet level (T1) of about 0.2 eV or less. ST Furthermore, it can be used as a thermally activated delayed fluorescence (TADF) dopant. Therefore, the organic electroluminescent device 10 of the embodiment may include at least one of the compounds selected from those described in this embodiment as a TADF dopant in the emitting layer EML, and the emitting layer EML may emit delayed fluorescence. For example, the emitting layer EML may emit TADF.

[0147] The compounds of the embodiments have novel (e.g., improved) compound structures comprising a fused ring of benzoxazole and benzofuran as electron acceptors, and can be used as materials for emitting thermally activated delayed fluorescence. The compounds of the embodiments can be used as materials for the emitting layer of organic electroluminescent devices and can improve the emission efficiency and increase the lifetime of organic electroluminescent devices. In particular, the compounds according to the embodiments can be used as luminescent materials emitting light in the blue or green wavelength region and can exhibit superior emission efficiency.

[0148] In embodiments, the emission layer EML may be a delayed fluorescence emission layer, and the emission layer EML may include any suitable host material and the compounds described above in the embodiments. For example, in embodiments, the emission layer EML may include the compounds described in the embodiments as dopant materials, and may include tris(8-hydroxyquinoline)aluminum (Alq3), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), poly(N-vinylcarbazole) (PVK), 9,10-bis(naphthyl-2-yl)anthracene (ADN), 4,4',4”-tris(carbazolyl-9-yl)-triphenylamine (TCTA), 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 3-tert-butyl-9,10-bis(naphthyl-2-yl)anthracene (TBADN), stilbeneyl aromatics (DSA), 4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl as host materials. Examples of suitable host materials include CDBP, 2-methyl-9,10-bis(naphthyl-2-yl)anthracene (MADN), bis[2-(diphenylphosphine)phenyl]ether oxide (DPEPO), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO3), octaphenylcyclotetrasiloxane (DPSiO4), 2,8-bis(diphenylphospho)dibenzo[b,d]furan (PPF), 3,3'-bis(N-carbazolyl)-1,1'-biphenyl (mCBP), and 1,3-bis(N-carbazolyl)benzene (mCP). However, embodiments of this disclosure are not limited thereto, and for example, any suitable host material for emitting delayed fluorescence may be included in addition to the host materials described above.

[0149] However, the embodiments disclosed herein are not limited thereto, and the compounds of the embodiments can be used as the host material of the emitter layer EML. If the compounds of the embodiments are used as the host material, any suitable dopant material other than the compounds of the embodiments in the emitter layer EML can be used.

[0150] In the organic electroluminescent device 10 of the embodiment, the emitting layer EML may include styrene derivatives as dopant materials (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styrene]stilbene (DPAVB) and / or N-(4-((E)-2-(6-((E)-4-(diphenylamino)styrene)) (N-BDAVBi)naphthyl-2-yl)vinyl)phenyl)-N-phenylaniline (N-BDAVBi)), perylene and / or its derivatives (e.g., 2,5,8,11-tetra-tert-butylperylene (TBP)), pyrene and / or its derivatives (e.g., 1,1'-dipyrene, 1,4-dipyrenebenzene, 1,4-bis(N,N-diphenylamino)pyrene), 1,2,3,5-tetra(carbazole-9-yl)-4,6-dicyanophenylene (4-CzIPN), etc.

[0151] If the emitting layer EML emits blue light, the emitting layer EML may further include a fluorescent material, which includes any one selected from the group consisting of: spiro-DPVBi, spiro-6P, stilbene (DSB), stilbene aromatics (DSA), polyfluorene (PFO)-based polymers, and poly(p-phenylenevinylene) polymers. If the emitting layer EML emits blue light, the emitting layer EML may include, for example, the compounds of the embodiments as the host material, and metal complexes, organometallic complexes (such as (4,6-F2ppy)2Irpic), perylene and / or their derivatives as dopant materials.

[0152] If the emitting layer EML emits green light, the emitting layer EML may further include a fluorescent material, which includes tris(8-hydroxyquinoline)aluminum (Alq3). If the emitting layer EML emits green light, the emitting layer EML may include, for example, the compounds of the embodiments as the host material, and metal complexes, organometallic complexes (such as planar-tris(2-phenylpyridine)iridium (Ir(ppy)3)), coumarin and / or their derivatives as dopant materials.

[0153] In some embodiments, the organic electroluminescent device 10 of the embodiment may include a plurality of emission layers EML. The plurality of emission layers EML can be provided by sequentially stacking. For example, the organic electroluminescent device 10 including a plurality of emission layers EML can emit white light. The organic electroluminescent device 10 including a plurality of emission layers EML can be an organic electroluminescent device with a series structure. In cases where the organic electroluminescent device 10 includes a plurality of emission layers EML, at least one emission layer EML may include the compound described above in the embodiment.

[0154] exist FIG. 1 to FIG. 4In the organic electroluminescent device 10 of the embodiment shown, the electron transport region (ETR) is provided on the emitter layer (EML). The electron transport region (ETR) may include at least one of the hole blocking layer (HBL), the electron transport layer (ETL), and the electron injection layer (EIL). However, embodiments of this disclosure are not limited thereto.

[0155] The electronic transport region (ETR) can have a single layer formed using a single material, a single layer formed using multiple different materials, or a multilayer structure with multiple layers formed using multiple different materials.

[0156] 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 a single-layer structure formed using an electron injection material and an electron transport material. In some embodiments, the ETR may have a single-layer structure having a variety of different materials, or a structure of electron transport layer ETL / electron injection layer EIL or hole blocking layer HBL / electron transport layer ETL / electron injection layer EIL stacked from the emitter layer (EML), without limitation. The thickness of the ETR may be, for example, approximately [missing information - likely a number]. to approximately

[0157] The electron transport region (ETR) can be formed using one or more suitable methods, such as vacuum deposition, spin coating, casting, Langmuir-Brookett (LB) method, inkjet printing, laser printing and / or laser-induced thermal imaging (LITI).

[0158] If the electron transport region ETR includes an electron transport layer ETL, then the electron transport region ETR may include anthracene compounds. The electron transport region ETR may include, for example, tris(8-hydroxyquinoline)aluminum (Alq3), 1,3,5-tris[(3-pyridyl)-benzyl-3-yl]benzene, 2,4,6-tris(3'-(pyridyl-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, 1,3,5-tris(1-phenyl-1H-benzimidazol-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-(naphth-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-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), bis(benzoquinoline-10-hydroxy)beryllium (Bebq2), 9,10-bis(naphth-2-yl)anthracene (ADN), 1,3-bis[3,5-bis(pyridin-3-yl)phenyl]benzene (BmPyPhB), or mixtures thereof, without limitation. The thickness of the electron transport layer (ETL) can be approximately [missing information]. to approximately And it can be, for example, about to approximately When the thickness of the electron transport layer (ETL) meets any of the above-mentioned ranges, satisfactory (or appropriate) electron transport properties can be obtained without a significant increase in the driving voltage.

[0159] If the electron transport region (ETR) includes an electron injection layer (EIL), the ETR may include metal halides (such as LiF, NaCl, CsF, RbCl, RbI, and / or CuI), lanthanide metals (such as Yb), metal oxides (such as Li₂O and / or BaO), and / or lithium 8-hydroxyquinoline (Liq). However, embodiments of this disclosure are not limited thereto. The electron injection layer (EIL) may be formed using a mixture of an electron transport material and an insulating organometallic salt. The insulating organometallic salt may be a material having a band gap of about 4 eV or greater. The insulating organometallic salt may include, for example, metal acetates, metal benzoates, metal acetoacetates, metal acetylacetonates, and / or metal stearates. The thickness of the electron injection layer (EIL) may be approximately [missing information - likely a value]. to approximately For example, about to approximately When the thickness of the electron injection layer (EIL) meets any of the above-mentioned ranges, satisfactory (or appropriate) electron injection properties can be obtained without causing a significant increase in the driving voltage.

[0160] The electron transport region (ETR) may include a hole blocking layer (HBL) as described above. The hole blocking layer (HBL) may include, for example, at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and 4,7-diphenyl-1,10-phenanthroline (Bphen). However, embodiments of this disclosure are not limited thereto.

[0161] The second electrode EL2 may be provided on the electron transport region (ETR). The second electrode EL2 may be a common electrode and / or a cathode. The second electrode EL2 may be a transmission electrode, a transmission-reflection electrode, or a reflection electrode. If the second electrode EL2 is a transmission electrode, it may include a transparent metal oxide, such as ITO, IZO, ZnO, ITZO, etc.

[0162] If the second electrode EL2 is a transmissive or reflective electrode, then the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, or Ti, or compounds thereof, or mixtures thereof (e.g., a mixture of Ag and Mg). The second electrode EL2 may have a multilayer structure, comprising a reflective or transmissive layer formed using any of the above materials and a transparent conductive layer formed using ITO, IZO, ZnO, ITZO, etc.

[0163] In some embodiments, the second electrode EL2 may be connected to an auxiliary electrode. When the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0164] Simultaneously, a capping layer CPL may be further provided on the second electrode EL2 of the organic electroluminescent device 10 in the embodiment. The capping layer CPL may include, for example, α-NPD (N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4'-diamine), NPB, TPD, m-MTDATA, Alq3, CuPc, N4,N4,N4',N4'-tetra(biphenyl-4-yl)biphenyl-4,4'-diamine (TPD15), 4,4',4"-tris(carbazole-9-yl)triphenylamine (TCTA), etc.

[0165] The organic electroluminescent device 10 according to embodiments of the present disclosure may include the compound of the embodiment in the emission layer EML between the first electrode EL1 and the second electrode EL2, and may exhibit improved emission efficiency. The compound of the embodiment may be a thermally activated delayed fluorescence dopant, and the emission layer EML may include the compound of the embodiment and emit thermally delayed fluorescence, thereby exhibiting superior (or improved) emission efficiency properties. For example, the compound of the embodiment may be used as a dopant material of the emission layer EML, and an organic electroluminescent device with superior (or improved) emission efficiency and long lifetime characteristics in the green or blue emission regions can be realized.

[0166] In some embodiments, the compound according to the embodiments may be included as the host material of the emission layer EML and may be used with suitable fluorescent dopant materials or suitable phosphorescent dopant materials to improve the emission efficiency and lifetime of the organic electroluminescent device.

[0167] Furthermore, the aforementioned compound described in the embodiments can be included in organic layers other than the emitting layer EML as a material for the organic electroluminescent device 10. For example, the organic electroluminescent device 10 according to an embodiment of the present disclosure may include the compound in at least one functional layer between the first electrode EL1 and the second electrode EL2 or in a capping layer CPL located on the second electrode EL2.

[0168] The compounds of the embodiments have novel compound structures comprising a fused ring of benzoxazole and benzofuran as electron acceptors, and can be used as materials for the emission layer, thereby contributing to increased efficiency of organic electroluminescent devices. Furthermore, organic electroluminescent devices comprising the compounds of the embodiments in the emission layer can exhibit high efficiency in the green or blue emission wavelength regions.

[0169] The following description, using both reference and comparative embodiments, will specifically explain the compounds and organic electroluminescent devices according to embodiments of this disclosure. However, the following embodiments are merely illustrative and the scope of this disclosure is not limited thereto.

[0170] Example

[0171] 1. Synthesis of the compounds in the embodiments

[0172] First, the methods for synthesizing the compounds according to embodiments of the present disclosure will be explained in more detail with reference to the synthesis methods of compounds 1, 3, 5, 30, 34, 52, 55, and 56. However, the synthesis methods of the compounds explained below are merely exemplary embodiments, and the synthesis methods of the compounds according to embodiments of the present disclosure are not limited thereto.

[0173] (1) Synthesis of compound 5

[0174] Compound 5 according to the embodiments can be synthesized, for example, by the following reaction 1 step (action):

[0175] Reaction 1

[0176]

[0177] Synthesis of Intermediate 1

[0178] Add 30.0 g (140.7 mmol) of 2-methoxydibenzo[b,d]furan-3-amine and 703 mL of dichloromethane (DCM) to a single-necked 3,000 mL flask, and cool the resulting product to approximately 0 °C. Dilute 105.7 g (422.08 mmol) of boron tribromide in 422 mL of dichloromethane, and slowly add the resulting boron tribromide solution (1.0 M DCM solution) to the flask at approximately 0 °C. Stir and proceed at approximately 0 °C for approximately 1 hour, and then at room temperature for approximately 4 hours. After the reaction is complete, cool the resulting product to approximately 0 °C, and slowly add 300 mL of distilled water. Dissolve 80.0 g (578.0 mmol) of K₂CO₃ in 289 mL of distilled water and then slowly add it to the solution at approximately 0 °C, adjusting the pH to 7 to 8, and then stir at approximately 0 °C for one day. The precipitated solid was washed with distilled water, filtered, and dried in a vacuum oven for one day. 31.5 g (crude) of a gray solid compound (intermediate 1) was obtained. Subsequent reactions were carried out without further separation.

[0179] Synthesis of intermediate 2

[0180] In a single-necked 1,000 mL flask, 12.8 g (64.3 mmol) of intermediate 1, 14.3 g (77.1 mmol) of 3-bromobenzaldehyde, and 321 mL of ethanol were mixed and stirred at room temperature for about 3 hours. After the reaction was complete, the precipitated solid was filtered and washed with ethanol. 19.0 g (yield: 80.7%) of a yellow solid compound (intermediate 2) was given.

[0181] Synthesis of intermediate 3

[0182] 19.0 g (51.8 mmol) of intermediate 2 and 517 mL of dichloromethane were added to a single-necked 1,000 mL flask and stirred at room temperature. 14.1 g (62.1 mmol) of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) was slowly added and stirred at room temperature for one day. After the reaction was complete, the product was passed through a diatomaceous earth pad with hot chloroform, and the solvent was removed by distillation under reduced pressure. The resulting compound was slurried using chloroform and methanol, and then filtered using methanol. 17.6 g (yield: 93.36%) of a beige solid compound (intermediate 3) was given.

[0183] Synthesis of Compound 5

[0184] In a single-necked 250 mL flask, 1.6 g (4.5 mmol) of intermediate 3, 1.5 g (9.0 mmol) of 9H-carbazole, 0.3 g (0.5 mmol) of Pd(dba)2, 0.26 g (0.5 mmol, 50 wt% toluene solution) of P(t-Bu)3, 1.5 g (15.8 mmol) of NaOtBu, and 45 mL of xylene were refluxed and stirred for one day. After cooling at room temperature, impurities were removed by diatomaceous earth filtration. After complete solvent removal, the crude product was separated by silica gel column chromatography (MC:Hex = 1:8 → 1:1). The resulting solid was solidified (acetone:MeOH = 2:1) and filtered to obtain 1.44 g (yield: 71%) of compound 5 as a reddish-brown solid. The molecular weight of compound 5, measured by fast atom bombardment mass spectrometry (FAB-MS), was MS[M+H]. + =451.

[0185] (2) Synthesis of compound 30

[0186] Compound 30 according to the embodiments can be synthesized, for example, by the following reaction 2 step (action):

[0187] Reaction 2

[0188]

[0189] Synthesis of intermediate 4

[0190] In a single-necked 1,000 mL flask, 12.8 g (64.3 mmol) of intermediate 1, 14.3 g (77.1 mmol) of 4-bromobenzaldehyde, and 321 mL of ethanol were mixed and stirred at room temperature for about 3 hours. After the reaction was complete, the precipitated solid was filtered while washing with ethanol. 18.5 g (yield: 79.1%) of a yellow solid compound (intermediate 4) was given.

[0191] Synthesis of intermediate 5

[0192] 18.5 g (50.8 mmol) of intermediate 4 and 517 mL of dichloromethane were added to a single-necked 1,000 mL flask and stirred at room temperature. 14.1 g (62.1 mmol) of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) was slowly added and stirred at room temperature for one day. After the reaction was complete, the product was passed through a diatomaceous earth pad with hot chloroform, and the solvent was removed by distillation under reduced pressure. The resulting compound was slurried using chloroform and methanol, and then filtered using methanol. 16.8 g (yield: 91.1%) of a beige solid compound (intermediate 5) was given.

[0193] Synthesis of Compound 30

[0194] In a single-necked 250 mL flask, 1.6 g (4.5 mmol) of intermediate 5, 1.9 g (9.1 mmol) of 9,9-dimethyl-9,10-dihydroacrylidine, 0.3 g (0.5 mmol) of Pd(dba)2, 0.26 g (0.5 mmol, 50 wt% toluene solution) of P(t-Bu)3, 1.5 g (15.8 mmol) of NaOtBu, and 45 mL of xylene were refluxed and stirred for one day. After cooling at room temperature, impurities were removed by diatomaceous earth filtration. After complete solvent removal, the crude product was separated by silica gel column chromatography (MC:Hex = 1:8 → 1:1). The resulting product was solidified (acetone:MeOH = 2:1) and filtered to obtain 1.66 g (yield: 75%) of compound 30 as a reddish-brown solid. The molecular weight of compound 30 was measured by FAB-MS as MS[M+H]. + =493.

[0195] (3) Synthesis of compound 34

[0196] Compound 34 according to the embodiments can be synthesized, for example, by the following reaction 3 step (action):

[0197] Reaction 3

[0198]

[0199] In a single-necked 250 mL flask, 1.6 g (4.5 mmol) of intermediate 3, 1.65 g (9.0 mmol) of 10H-phenoxazine, 0.3 g (0.5 mmol) of Pd(dba)2, 0.26 g (0.5 mmol, 50 wt% toluene solution) of P(t-Bu)3, 1.5 g (15.8 mmol) of NaOtBu, and 45 mL of xylene were refluxed and stirred for one day. After cooling at room temperature, impurities were removed by diatomaceous earth filtration. After complete solvent removal, the crude product was separated by silica gel column chromatography (MC:Hex = 1:8 → 1:1). The resulting product was solidified (acetone:MeOH = 2:1) and filtered to obtain 1.51 g (yield: 72%) of compound 34 as a reddish-brown solid. The molecular weight of compound 34, measured by FAB-MS, was MS[M+H]. + =467.

[0200] (4) Synthesis of compound 52

[0201] Compound 52 according to the embodiments can be synthesized, for example, by the following reaction 4 step (action):

[0202] Reaction 4

[0203]

[0204] Synthesis of intermediate 6

[0205] In a single-necked 2,000 mL flask, 31.5 g (158.1 mmol) of intermediate 1, 62.5 g (237.2 mmol) of 3,5-dibromobenzaldehyde, and 1,054 mL of ethanol were mixed and stirred at approximately 90 °C for approximately 4 hours. After the reaction was complete, the resulting product was cooled to room temperature. The precipitated solid was filtered and washed with ethanol. 42.1 g (yield: 60.0%) of a brown solid compound (intermediate 6) was given.

[0206] Synthesis of intermediate 7

[0207] 42.05 g (94.4 mmol) of intermediate 6 and 765 mL of dichloromethane were added to a single-necked 2,000 mL flask and stirred at room temperature. 31.3 g (137.78 mmol) of 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) was slowly added and stirred at approximately 40 °C for about 3 hours. After the reaction was complete, the reaction product was passed through a diatomaceous earth pad using hot chloroform, and the solvent was removed by distillation under reduced pressure. The resulting compound was slurried using 50 mL of chloroform and 500 mL of methanol, and then filtered using methanol to obtain 33.4 g (yield: 79.8%) of a beige solid compound (intermediate 7).

[0208] Synthesis of Compound 52

[0209] In a single-necked 250 mL flask, 3.0 g (6.8 mmol) of intermediate 7, 2.5 g (13.9 mmol) of phenoxazine, 0.4 g (0.68 mmol) of Pd(dba)2, 0.4 g (1.0 mmol) of S-phos, 2.0 g (20.3 mmol) of NaOtBu, and 45 mL of xylene were refluxed and stirred for approximately 30 minutes. After cooling to room temperature, methanol was added to solidify. After filtration, the resulting solid was dissolved in chloroform by heating and then separated by silica gel column chromatography (CHCl3:Hex = 1:4 → 2:1). A small amount of acetone was added to the product obtained by heating in chloroform and then cooling sufficiently to solidify. The resulting solid was filtered to obtain 1.9 g (yield: 44.2%) of compound 52 as a yellow solid. The molecular weight of compound 52, as measured by FAB-MS, was MS[M+H]. + =648.

[0210] (5) Synthesis of compound 55

[0211] Compound 55 according to the embodiments can be synthesized, for example, by the following reaction 5 step (action):

[0212] Reaction 5

[0213]

[0214] In a single-necked 250 mL flask, 1.6 g (4.5 mmol) of intermediate 3, 3.0 g (9.0 mmol) of N,N-diphenyl-9H-carbazole-2-amine, 0.3 g (0.5 mmol) of Pd(dba)2, 0.26 g (0.5 mmol, 50 wt% toluene solution) of P(t-Bu)3, 1.5 g (15.8 mmol) of NaOtBu, and 45 mL of xylene were refluxed and stirred for one day. After cooling at room temperature, impurities were removed by diatomaceous earth filtration. After complete solvent removal, the crude product was separated by silica gel column chromatography (MC:Hex = 1:8 → 1:1). The resulting product was solidified (acetone:MeOH = 2:1) and filtered to obtain 2.0 g (yield: 71.2%) of compound 55 as a reddish-brown solid. The molecular weight of compound 55 was measured by FAB-MS as MS[M+H]. + =618.

[0215] (6) Synthesis of compound 56

[0216] Compound 56 according to the embodiments can be synthesized, for example, by the following reaction 6 step (action):

[0217] Reaction 6

[0218]

[0219] In a single-necked 250 mL flask, 2.0 g (4.5 mmol) of intermediate 7, 3.0 g (9.0 mmol) of N,N-diphenyl-9H-carbazole-2-amine, 0.3 g (0.5 mmol) of Pd(dba)2, 0.26 g (0.5 mmol, 50 wt% toluene solution) of P(t-Bu)3, 1.5 g (15.8 mmol) of NaOtBu, and 45 mL of xylene were refluxed and stirred for one day. After cooling at room temperature, impurities were removed by diatomaceous earth filtration. After complete solvent removal, the crude product was separated by silica gel column chromatography (MC:Hex = 1:8 → 1:1). The resulting product was solidified (acetone:MeOH = 2:1) and filtered to obtain 2.6 g (yield: 61.5%) of compound 56 as a reddish-brown solid. The molecular weight of compound 56, measured by FAB-MS, was MS[M+H]. + =950.

[0220] (7) Synthesis of Compound 1

[0221] Compound 1 according to the embodiments can be synthesized, for example, by the following reaction 7 step (action):

[0222] Reaction 7

[0223]

[0224] In a single-necked 250 mL flask, 1.6 g (4.5 mmol) of intermediate 3, 1.0 g (6.0 mmol) of 1-naphth-1-ylboronic acid, and 100 mL of toluene were refluxed and stirred for one day. The resulting product was then cooled, and the solvent was completely removed. The crude product was separated by silica gel column chromatography (MC:Hex = 1:4) to obtain 1.70 g (yield: 92.0%) of compound 1 as a white solid. The molecular weight of compound 1, measured by FAB-MS, was [M+H] in MS. + =412.

[0225] (8) Synthesis of compound 3

[0226] Compound 3 according to the embodiments can be synthesized, for example, by the following reaction 8 step (action):

[0227] Reaction 8

[0228]

[0229] In a single-necked 250 mL flask, 1.6 g (4.5 mmol) of intermediate 3, 1.6 g (6.0 mmol) of 2-triphenyl-1-ylboronic acid, and 100 mL of toluene were mixed and refluxed for one day. The resulting product was then cooled, and the solvent was completely removed. The crude product was separated by silica gel column chromatography (MC:Hex = 1:4) to obtain 1.91 g (yield: 88.3%) of compound 3 as a white solid. The molecular weight of compound 3, measured by FAB-MS, was [M+H] MS. + =512.

[0230] 2. Evaluation of compounds

[0231] The fluorescence properties of the compounds synthesized in this embodiment were evaluated. The fluorescence properties of the compounds were compared with those of the example compounds. The compounds used for evaluation are shown below.

[0232] (Example compounds used for evaluating luminescent properties)

[0233]

[0234] (Comparative compounds used to evaluate luminescent properties)

[0235]

[0236] ΔE of the example compounds and comparative compounds used to evaluate the implementation methods ST Values ​​and emission wavelengths. The evaluation results of these properties are shown in Table 1. ΔE ST The difference between the lowest singlet excitation level (S1 level) and the lowest triplet excitation level (T1 level) is used, and ΔE is calculated using the Gaussian method (basis set B3LYP / 6-31G*). ST Furthermore, emission spectra were used to confirm the emission wavelengths of the compounds in the examples and the comparative compounds.

[0237] Table 1

[0238] Classification ΔE ST ]]> Emission wavelength Compound 5 0.35 eV Blue Compound 30 0.01 eV Green Compound 34 0.02 eV Green Compound 52 0.02 eV Green Compound 55 0.01 eV Blue Compound 56 0.01 eV Green Compound C1 0.57 eV Blue Compound C2 0.01 eV Green

[0239] Referring to the results in Table 1, the compounds of this embodiment can be used as luminescent materials emitting blue or green light. Furthermore, compounds 30, 34, 52, 55, and 56, etc., have a small ΔE of approximately 0.02 eV or less. ST It has a value and is considered suitable for use as a material for emitting delayed fluorescence.

[0240] 3. Fabrication and evaluation of organic electroluminescent devices

[0241] 3-1. Example A of an organic electroluminescent device including the compound of the embodiment.

[0242] An organic electroluminescent device comprising an embodiment of a compound as the main material of an emitting layer is manufactured by the method described below.

[0243] Manufacturing of organic electroluminescent devices

[0244] The glass substrate with patterned ITO was cleaned using ultrapure water and ultrasonic cleaning, exposed to UV for approximately 30 minutes, and treated with ozone, serving as the first electrode. Then, HT1 was deposited to approximately... The thickness, and deposit HT2 to approximately The thickness is increased to form a hole transport region.

[0245] Then, the example compound or comparative compound was co-deposited with 4CzIPN at a ratio of approximately 80:20 to form an emission layer. The thickness. That is, the emission layer of each embodiment is obtained by co-deposition by mixing and depositing the corresponding embodiment compound with 4CzIPN, and the emission layer of each comparative example is obtained by mixing and depositing the corresponding comparative compound with 4CzIPN.

[0246] Then, ET and Liq were mixed in a 5:5 ratio and deposited on the emitter layer to form a structure with approximately A layer of approximately [thickness], and formed using Liq. A layer of this thickness is formed, thus creating an electron transport region. Then, a second electrode is formed using Mg:Ag (10:1) to approximately [thickness missing]. The thickness.

[0247] In the embodiments and comparative examples, the hole transport region, the emitter layer, the electron transport region, and the second electrode are formed using a vacuum deposition apparatus. The materials for the hole transport region, the electron transport region, and the dopant material for the fabrication of an organic electroluminescent device are shown below.

[0248]

[0249] Evaluation of the properties of organic electroluminescent devices

[0250] Table 2 compares the efficiency, lifetime, and emission color of the organic electroluminescent devices thus manufactured. In the evaluation results of the properties of the examples and comparative examples shown in Table 2, efficiency is expressed relative to 10 mA / cm². 2 The current efficiency value of the current density. Furthermore, in the evaluation results of the emission properties of the organic electroluminescent device, when the efficiency and lifetime of Comparative Example 1-1 were set to 100%, the efficiency and lifetime of the comparative examples were used as relative values.

[0251] In Examples 1-1 and 1-2, Compound 1 and Compound 3 were used as the host materials for the emission layer, respectively. In Comparative Example 1-1, the known host material mCBP was used as the host material for the emission layer.

[0252] Table 2

[0253] Classification Host Dopant Efficiency Lifetime Emission color Example 1-1 Compound 1 4CzIPN 95％ 140％ Green Example 1-2 Compound 3 4CzIPN 105％ 155％ Green Comparative example 1-1 mCBP 4CzIPN 100％ 100％ Green

[0254] Referring to the results in Table 2, it can be confirmed that Examples 1-1, 1-2, and Comparative Example 1-1 all emitted light in the green wavelength region. When compared with Comparative Example 1-1, it can be found that Example 1-1 exhibits slightly reduced efficiency but improved lifetime characteristics. Furthermore, when compared with Comparative Example 1-1, it can be found that Example 1-2 exhibits improved efficiency and improved lifetime characteristics.

[0255] Therefore, it can be found that the compound according to the embodiments can be used as a host material for an emitting layer that emits light in the green wavelength region, and can exhibit superior (or improved) lifetime characteristics when compared with comparable host materials.

[0256] 3-2. Example B of an organic electroluminescent device including the compounds of the embodiments.

[0257] An organic electroluminescent device comprising an embodiment of a compound that serves as a dopant material for an emission layer is manufactured by the method described below.

[0258] Manufacturing of organic electroluminescent devices

[0259] A glass substrate patterned with ITO was cleaned with ultrapure water and ultrasonically, exposed to UV for approximately 30 minutes, and treated with ozone, serving as the first electrode. Then, HT1 was deposited to approximately... The thickness, and deposit HT2 to approximately The thickness is increased to form a hole transport region.

[0260] Then, the example compound or comparative compound was co-deposited with mCBP at a ratio of 20:80 to form an emission layer. The thickness. That is, the emission layer of each embodiment is obtained by co-deposition by mixing and depositing the corresponding embodiment compound with mCBP, and the emission layer of each comparative example is obtained by mixing and depositing the corresponding comparative compound with mCBP.

[0261] Then, ET and Liq were mixed in a 5:5 ratio and deposited on the emitter layer to form a structure with approximately A layer of approximately [thickness], and formed using Liq. A layer of this thickness is formed, thus creating an electron transport region. Then, a second electrode is formed using Mg:Ag (10:1) to approximately [thickness missing]. The thickness.

[0262] In the embodiments and comparative examples, a vacuum deposition apparatus was used to form a hole transport region, an emitter layer, an electron transport region, and a second electrode.

[0263] Evaluation of the properties of organic electroluminescent devices

[0264] Table 3 compares the efficiency, lifetime, and emission color of the organic electroluminescent devices thus manufactured. In the evaluation results of the properties of the examples and comparative examples shown in Table 3, efficiency is expressed relative to 10 mA / cm². 2 The current efficiency value of the current density. Furthermore, in the evaluation results of the properties of the organic electroluminescent device, when the efficiency and lifetime of Comparative Example 2-1 or Comparative Example 3-1 were set to 100%, the efficiency and lifetime of the comparative examples were used as relative values.

[0265] In the evaluation results shown in Table 3 below, Examples 2-1, 2-2, and Comparative Example 2-1 show the evaluation results of organic electroluminescent devices emitting light in the blue wavelength region, and Examples 3-1 to 3-4 and Comparative Example 3-1 show the evaluation results of organic electroluminescent devices emitting light in the green wavelength region. In Examples 2-1, 2-2, 2-1, 3-1 to 3-4, and Comparative Example 3-1, the known host material mCBP was used as the host material of the emitting layer.

[0266] Table 3

[0267] Classification Host Dopant Efficiency Lifetime Emission color Example 2-1 mCBP Compound 5 130％ 130％ Blue Example 2-2 mCBP Compound 55 135％ 130％ Blue Comparative example 2-1 mCBP Comparative compound C1 100％ 100％ Blue Example 3-1 mCBP Compound 30 110％ 135％ Green Example 3-2 mCBP Compound 34 115％ 140％ Green Example 3-3 mCBP Compound 52 115％ 125％ Green Example 3-4 mCBP Compound 56 125％ 180％ Green Comparative example 3-1 mCBP Comparative compound C2 100％ 100％ Green

[0268] Referring to the results in Table 3, it can be confirmed that the embodiments correspond to organic electroluminescent devices that emit blue or green light, and the compounds according to the embodiments can be used as blue dopants that emit blue light or green dopants that emit green light.

[0269] Furthermore, referring to the results in Table 3, when compared with Comparative Example 2-1, Examples 2-1 and 2-2 showed improved efficiency properties and lifetime characteristics, and when compared with Comparative Example 3-1, Examples 3-1 to 3-4 showed improved efficiency properties and superior lifetime characteristics.

[0270] Therefore, referring to the evaluation results in Table 3, it can be confirmed that the compounds according to the embodiments can be used as dopant materials for the emitting layer of organic electroluminescent devices to emit blue or green light. Furthermore, it can be found that, compared with comparative compounds, the compounds of this embodiment comprise a fused structure of benzofuran and benzoxazole, and when used as dopant materials for the emitting layer, the efficiency and lifetime characteristics of the organic electroluminescent device can be improved.

[0271] The compounds of the embodiments have novel compound structures comprising a fused ring of benzofuran and benzoxazole as electron acceptors, and when used as materials for the emission layer, they contribute to increased efficiency and long lifetime characteristics of organic electroluminescent devices. Furthermore, organic electroluminescent devices comprising the compounds of the embodiments in the emission layer exhibit superior emission properties and superior lifetime characteristics in the green or blue emission wavelength regions.

[0272] The organic electroluminescent device of the embodiment can exhibit improved device characteristics, including high efficiency and long lifetime in the green or blue wavelength regions.

[0273] The compounds of the embodiments may be included in the emitting layer of the organic electroluminescent device and may contribute to the improvement of the lifetime characteristics and increase the efficiency of the organic electroluminescent device.

[0274] As used herein, the terms “use,” “using,” and “used” can be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively.

[0275] Furthermore, the terms “basically,” “about,” and similar terms are used as approximate terms rather than terms of degree, and are intended to describe the inherent biases in measurements or calculations that would be recognized by a person skilled in the art.

[0276] Furthermore, any numerical ranges listed herein are intended to include all subranges with the same numerical precision within the listed range. For example, the range “1.0 to 10.0” is intended to include all subranges between (and including) the listed minimum value of 1.0 and the listed maximum value of 10.0, that is, a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limit listed herein is intended to include all lower numerical limits included therein, and any minimum numerical limit listed in this specification is intended to include all higher numerical limits included therein. Therefore, the applicant reserves the right to amend this specification (including the claims) to expressly list any subranges within the ranges expressly listed herein.

[0277] Although exemplary embodiments of this disclosure have been described, it should be understood that this disclosure is not intended to be limited to these exemplary embodiments, but rather that various changes and modifications may be made by those skilled in the art within the spirit and scope of this disclosure as claimed in the appended claims and their equivalents.

Claims

1. A compound, represented by Formula 1, wherein said compound is used as a dopant in the emitting layer of an organic electroluminescent device: Formula 1 In Equation 1, X1 to X4 are each independently CR a , L is a polyvalent aryl group with 6 to 30 substituted or unsubstituted carbon atoms for ring formation, or a polyvalent heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms for ring formation. n is 1 or 2, Ar can be a hydrocarbon cyclogroup of 6 to 30 carbon atoms, substituted or unsubstituted, used to form the ring, or can be represented by any one of formulas 2-2A to 2-2E. Formula 2-2A Formula 2-2B Formula 2-2C Equation 2-2D Formula 2-2E In equation 2-2E, b1 is an integer selected from 0 to 3, b2 is an integer selected from 0 to 4, and R b1 and R b2 Each of the following groups is independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amino group, an alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for ring formation, or a heteroaryl group with 2 to 30 carbon atoms for ring formation, and / or combined with adjacent groups to form a ring. In equations 2-2A to 2-2E, b and c are each independently an integer selected from 0 to 4. Refers to the connection position. In equations 2-2A to 2-2C and 2-2E, R b and R c Each of the following groups is independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amino group, an alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for ring formation, or a heteroaryl group with 2 to 30 carbon atoms for ring formation, and / or combined with adjacent groups to form a ring. In Equation 2-2D, R b and R c Each of the following groups is independently composed of a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amino group, an alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for ring formation, or a heteroaryl group with 2 to 30 carbon atoms for ring formation. R a It is a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amino group, an alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for forming a ring, or a heteroaryl group with 2 to 30 carbon atoms for forming a ring, and / or combined with adjacent groups to form a ring.

2. The compound according to claim 1, wherein formula 1 is represented by formula 1-1: Formula 1-1 In Equation 1-1, L, n, and Ar are the same as those defined in Equation 1.

3. The compound according to claim 1, wherein the compound represented by formula 1 is a green dopant to emit green light having a center wavelength of 500 nm to 550 nm.

4. The compound according to claim 1, wherein the compound represented by formula 1 is a blue dopant to emit blue light having a center wavelength of 420 nm to 470 nm.

5. The compound according to claim 1, wherein the compound represented by formula 1 has an absolute value ΔE of the difference between the lowest excited singlet level S1 and the lowest excited triplet level T1, which is 0.2 eV or less. ST .

6. The compound according to claim 1, wherein the compound represented by formula 1 is represented by any one of the compounds selected from group 1: Compound group 1 7. An organic electroluminescent device, comprising: First electrode; The second electrode on the first electrode; as well as An emission layer between the first electrode and the second electrode, the emission layer comprising a compound according to any one of claims 1 to 6.

8. The organic electroluminescent device according to claim 7, wherein in the compound, L is a substituted or unsubstituted phenylene or a substituted or unsubstituted pyridylene.

9. The organic electroluminescent device according to claim 7, wherein the emitting layer emits delayed fluorescence, and The compound is a delayed fluorescence dopant.

10. The organic electroluminescent device according to claim 7, wherein the emitting layer emits light having a center wavelength of 500 nm to 550 nm, or emits light having a center wavelength of 420 nm to 470 nm.

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