Organic electroluminescent device and compound for organic electroluminescent device

Abstract

To provide: an organic electroluminescence device exhibiting excellent luminous efficiency and long-life properties; and a compound being an organic electroluminescence device material having high efficiency and long-life properties.SOLUTION: An organic electroluminescence device of an embodiment includes a first electrode, a second electrode, and a luminous layer between the first electrode and the second electrode, where the luminous layer includes a compound represented by the chemical formula 1 in the figure. The compound includes as an electron acceptor part a composite ring in which benzofuran is fused to benzoxazole, and thus exhibits good luminous efficiency properties and long-life properties.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an organic electroluminescent device and a compound used therein, and more particularly to a compound used as a light-emitting material and an organic electroluminescent device containing the same. [Background technology]

[0002] Recently, organic electroluminescence displays (OLEDs) have been actively developed as image display devices. Unlike liquid crystal displays, OLEDs are so-called self-luminous displays that realize display by recombining holes and electrons injected from a first electrode and a second electrode in a light-emitting layer to cause a light-emitting material containing an organic compound in the light-emitting layer to emit light.

[0003] In order to apply organic electroluminescent devices to display devices, there is a demand for lower driving voltages, higher luminous efficiency, and longer life for the organic electroluminescent devices, and there is a continuous demand for the development of materials for organic electroluminescent devices that can stably achieve these demands.

[0004] In particular, in recent years, technologies related to phosphorescence that utilizes the energy of triplet states and delayed fluorescence that utilizes the phenomenon in which singlet excitons are generated by the collision of triplet excitons (triplet-triplet annihilation (TTA)) have been developed to realize highly efficient organic electroluminescent devices, and thermally activated delayed fluorescence (TADF) materials that utilize the delayed fluorescence phenomenon are being developed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Korean Patent No. 1117621 [Patent Document 2] Korean Patent No. 1297518 [Patent Document 3] Korean Patent Publication No. 2015-0050570 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an organic electroluminescent device that exhibits excellent luminous efficiency and long life characteristics.

[0007] Another object of the present invention is to provide a compound which is a material for organic electroluminescent devices having high efficiency and long life characteristics. [Means for solving the problem]

[0008] According to one embodiment, there is provided a compound represented by the following Chemical Formula 1: [ka] ...(chemical formula 1) In the above Chemical Formula 1, X 1 ~X 4 are each independently CR a L is a substituted or unsubstituted arylene group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring carbon atoms. n is 1 or 2. Ar is a substituted or unsubstituted hydrocarbon ring group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 2 to 30 ring carbon atoms. R a 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, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having from 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having from 2 to 30 ring carbon atoms, and may be bonded to adjacent groups to form a ring.

[0009] The above-mentioned formula 1 may be represented by the following formula 1-1. [ka] ...(chemical formula 1-1) In Formula 1-1, L, n, and Ar are as defined in Formula 1.

[0010] Ar may be an unsubstituted aryl group having 6 to 20 ring carbon atoms, or a substituted or unsubstituted heteroaryl group containing at least one of N, O, and B as a ring atom and having 2 to 20 ring carbon atoms.

[0011] Ar may be represented by the following formula 2: [ka] ...(chemical formula 2) In the above formula 2, Y is N or B, and Z is a direct linkage, O, S, or NR d , or CR e R f where b and c are each independently an integer between 0 and 4. b ~R f are each 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, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having from 6 to 30 ring carbon atoms, or an unsubstituted heteroaryl group having from 2 to 30 ring carbon atoms, and adjacent groups may be bonded to each other to form a ring.

[0012] The formula 2 may be represented by the following formula 2-1 or 2-2. [ka] ...(chemical formula 2-1) [ka] ...(chemical formula 2-2) In the above Chemical Formula 2-1 and Chemical Formula 2-2, Z, R b, R c , b, and c are as defined in Formula 2 above.

[0013] The formula 2-2 may be represented by any one of the following formulas 2-2A to 2-2E. [ka] ...(chemical formula 2-2A) [ka] ...(Chemical formula 2-2B) [ka] ...(chemical formula 2-2C) [ka] ...(chemical formula 2-2D) [ka] ...(chemical formula 2-2E) In the above Chemical Formula 2-2E, b1 is an integer of 0 to 3, b2 is an integer of 0 to 4, and R b1 and R b2 are each 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, 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 an unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, and may be bonded to adjacent groups to form a ring. b , R c , b, and c are as defined in Formula 2 above.

[0014] The compound represented by Chemical Formula 1 may be a green dopant that emits green light having a central wavelength of 500 nm to 550 nm.

[0015] The compound represented by Chemical Formula 1 may be a blue dopant that emits blue light having a central wavelength of 420 nm to 470 nm.

[0016] The compound represented by the formula 1 has an absolute value of the difference between the lowest excited singlet energy level (S1) and the lowest excited triplet energy level (T1) (ΔE ST ) may be 0.2 eV or less.

[0017] According to another embodiment, there is provided an organic electroluminescent device comprising a first electrode, a second electrode provided on the first electrode, and an emitting layer provided between the first electrode and the second electrode and including the compound according to the above-described embodiment.

[0018] The light-emitting layer may include a host and a dopant, and the host may include a compound according to one embodiment.

[0019] The light-emitting layer may emit delayed fluorescence, and the compound may be a delayed fluorescence dopant.

[0020] The light emitting layer may emit light having a central wavelength of 500 nm or more and 550 nm or less, or light having a central wavelength of 420 nm or more and 470 nm or less. Effect of the Invention

[0021] An organic electroluminescent device according to an embodiment exhibits improved device characteristics of high efficiency and long life in the green or blue wavelength region.

[0022] The compound according to one embodiment is contained in the light-emitting layer of an organic electroluminescent device to improve the life characteristics of the organic electroluminescent device and contribute to high efficiency. [Brief description of the drawings]

[0023] [Figure 1] 1 is a cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present invention. [Diagram 3] 1 is a cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present invention. [Figure 4] 1 is a cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Since the present invention can be modified in various ways and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text, but it is not intended to limit the present invention to the specific disclosed forms, and it should be understood that the present invention includes all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0025] As used herein, when a component (or region, layer, portion, etc.) is referred to as being "on" or "coupled" to another component, it means that it may be directly disposed, coupled, or connected to the other component, or that a third component may be disposed therebetween.

[0026] The same reference numerals refer to the same components. Also, in the drawings, thicknesses, proportions and dimensions of the components are exaggerated for the purpose of effectively explaining the technical contents.

[0027] "And / or" includes all combinations of one or more of the associated construct.

[0028] Terms such as "first" and "second" are used to describe various components, but the components are not limited to the terms. The terms are used only to distinguish one component from another. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component, without departing from the scope of the present invention. A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0029] In addition, terms such as "under", "below", "up" and "above" are used to describe the relationship between components shown in the drawings. The terms are relative concepts and are described based on the directions shown in the drawings.

[0030] 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 the present invention belongs. Furthermore, terms such as those defined in commonly used dictionaries should be interpreted to have a meaning consistent with the meaning in the context of the relevant art, and are expressly defined herein, unless interpreted in an idealized or overly formal sense.

[0031] It should be understood that the terms "comprise" or "have" imply the presence of any feature, numeral, step, operation, component, part, or combination thereof set forth in the specification above, but do not preclude the presence or additional possibility of one or more other features, numerals, steps, operations, components, parts, or combinations thereof.

[0032] On the other hand, in this specification, "substituted or unsubstituted" means that the group is substituted or unsubstituted with one or more substituents 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 oxy group, a thio 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 alkoxy group, a hydrocarbon ring group, an aryl group, and a heterocyclic group. In addition, each of the substituents exemplified above may be substituted or unsubstituted. For example, a biphenylyl group may be interpreted as an aryl group, or as a phenyl group substituted with a phenyl group.

[0033] In this specification, "adjacent groups bond together to form a ring" means adjacent groups bond together to form a substituted or unsubstituted hydrocarbon ring, or a substituted or unsubstituted hetero ring. Hydrocarbon rings include aliphatic hydrocarbon rings and aromatic hydrocarbon rings. Heterocyclic groups include aliphatic heterocyclic groups and aromatic heterocyclic groups. The ring formed by bonding adjacent groups together is a monocyclic or polycyclic ring. In addition, the ring formed by bonding together may be bonded to another ring to form a spiro structure.

[0034] In this specification, the term "adjacent groups" refers to a substituent substituted on an atom directly bonded to the atom on which the substituent is substituted, another substituent substituted on an atom on which the substituent is substituted, or a substituent that is sterically most adjacent to the substituent. For example, two methyl groups in 1,2-dimethylbenzene are interpreted as "adjacent groups" to each other, and two ethyl groups in 1,1-diethylcyclopentane are interpreted as "adjacent groups" to each other.

[0035] In this specification, examples of halogen atoms include a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0036] In this specification, an alkyl group is linear, branched, or cyclic. The number of carbon atoms in an alkyl group is 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl, i-butyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, i-pentyl, neopentyl, t-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl ...3,3-dimethylbutyl, n-pentyl, i-pentyl, neopentyl, t-pentyl, cyclopentyl, 3,3-dimethylbutyl, n-pentyl, i-pentyl, i-pentyl, i-pentyl, i-pentyl, i-pentyl, i-pentyl, i-pentyl, i-pentyl, i-pentyl, i-pentyl, i-pentyl, i-pentyl, Hexyl, 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 n-butyldecyl, 2-ethyldecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyldecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl , n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-icosyl group, 2-ethylicosyl group, 2-butylicosyl group, 2-hexylicosyl group, 2-octylicosyl group, n-henicosyl group, n-docosyl group, n-tricosyl group, n-tetracosyl group, n-pentacosyl group, n-hexacosyl group, n-heptacosyl group, n-octacosyl group, n-nonacosyl group, and n-triacontyl group, but are not limited to these.

[0037] In this specification, the hydrocarbon ring is an aliphatic hydrocarbon ring or an aromatic hydrocarbon ring having 5 to 60, 5 to 30, or 5 to 20 ring carbon atoms. The hydrocarbon ring group is any functional group or substituent derived from an aliphatic hydrocarbon ring, or any functional group or substituent derived from an aromatic hydrocarbon ring.

[0038] In this specification, the aryl group means any functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group is a monocyclic aryl group or a polycyclic aryl group. The number of ring carbon atoms of the aryl group is 6 to 30, 6 to 20, or 6 to 15. Examples of the aryl group include, but are not limited to, a phenyl group, a naphthyl group, a fluorenyl group, an anthracenyl group, a phenanthryl group, a biphenylyl group, a terphenylyl group, a quaterphenylyl group, a quinquephenylyl group, a sexiphenylyl group, a triphenylenyl group, a pyrenyl group, a benzofluoranthenyl group, and a chrysenyl group.

[0039] In this specification, a heterocyclic group refers to any functional group or substituent derived from a ring containing one or more of B, O, N, P, Si, and S as heteroatoms. Heterocyclic groups include aliphatic heterocyclic groups and aromatic heterocyclic groups. Aromatic heterocyclic groups are heteroaryl groups. The aliphatic heterocycles and aromatic heterocycles are monocyclic or polycyclic.

[0040] In this specification, the heterocycle includes one or more of B, O, N, P, Si, and S as a heteroatom. If the heterocycle includes two or more heteroatoms, the two or more heteroatoms may be the same or different. The heterocycle may be a monocyclic heterocycle or a polycyclic heterocycle, and includes heteroaryl. The number of ring carbon atoms of the heterocycle is 2 to 30, 2 to 20, or 2 to 10.

[0041] In this specification, the number of ring carbon atoms of the aliphatic heterocyclic group is from 2 to 30, from 2 to 20, or from 2 to 10. Examples of the aliphatic heterocyclic group include, but are not limited to, an oxiranyl group, a thiiranyl group, a pyrrolidinyl group, a piperidinyl group, a tetrahydrofuranyl group, a tetrahydrothiophenyl group, a thianyl group, a tetrahydropyranyl group, and a 1,4-dioxanyl group.

[0042] In the present specification, when a heteroaryl group contains two or more heteroatoms, the two or more heteroatoms may be the same or different. The heteroaryl group is a monocyclic heterocyclic group or a polycyclic heterocyclic group. The number of ring carbon atoms of the heteroaryl group is 2 to 30, 2 to 20, or 2 to 10. Examples of the heteroaryl group include a thiophenyl group, a furanyl group, a pyrrolyl group, an imidazolyl group, a triazolyl group, a pyridinyl group, a bipyridinyl group, a pyrimidinyl group, a triazinyl group, an acridinyl group, a pyridazinyl group, a quinolinyl group, a quinazolinyl group, a quinoxalinyl group, a phenoxanyl group, a phthalazinyl group, a pyridopyrimidinyl group, a pyridopyrazinyl group, a pyrazinopyrazinyl group, an isoquinolinyl group, an indolyl group, a carbazolyl group, an N-arylcarbazolyl group, an N-heteroaryl group, an N-arylcarbazolyl ... Examples of such alkyl groups include, but are not limited to, an arylcarbazolyl group, an N-alkylcarbazolyl group, a benzoxazolyl group, a benzimidazolyl group, a benzothiazolyl group, a benzocarbazolyl group, a benzothiophenyl group, a dibenzothiophenyl group, a thienothiophenyl group, a benzofuranyl group, a phenanthrolinyl group, a thiazolyl group, an isoxazolyl group, an oxazolyl group, an oxadiazolyl group, a thiadiazotyl group, a phenothiazinyl group, a dibenzosilolyl group, and a dibenzofuranyl group.

[0043] In this specification, the number of carbon atoms of the amino group is not particularly limited, but is 1 to 30. The amino group includes an alkylamino group and an arylamino group. Examples of the amino group include, but are not limited to, a methylamino group, a dimethylamino group, a phenylamino group, a diphenylamino group, a naphthylamino group, a 9-methyl-anthracenylamino group, and a triphenylamino group. For example, the alkyl group in the alkylamino group is the same as the above-mentioned alkyl group, and the aryl group in the arylamino group is the same as the above-mentioned aryl group.

[0044] In this specification, a direct bond means a single bond.

[0045] JPEG0007671937000011.jpg17159

[0046] Hereinafter, an organic electroluminescent device according to an embodiment of the present invention and a compound according to an embodiment included therein will be described with reference to the drawings.

[0047] 1 to 4 are cross-sectional views each showing a schematic configuration of an organic electroluminescent device according to an embodiment of the present invention. Referring to Fig. 1 to Fig. 4, in an organic electroluminescent device 10 according to an embodiment of the present invention, a first electrode EL1 and a second electrode EL2 are provided facing each other, and an emission layer EML is provided between the first electrode EL1 and the second electrode EL2.

[0048] The organic electroluminescent device 10 according to an embodiment further includes a plurality of functional layers between the first electrode EL1 and the second electrode EL2 in addition to the emission layer EML. The plurality of functional layers include a hole transport region HTR and an electron transport region ETR. That is, the organic electroluminescent device 10 according to an embodiment of the present invention includes 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 sequence. The organic electroluminescent device 10 according to an embodiment may further include a capping layer CPL provided on the second electrode EL2.

[0049] The organic light-emitting device 10 according to an embodiment includes a compound according to an embodiment described below in the emitting layer EML provided between the first electrode EL1 and the second electrode EL2. However, the embodiment of the present disclosure is not limited thereto, and the organic light-emitting device 10 according to an embodiment may include a compound according to an embodiment described below included in the hole transport region HTR or the electron transport region ETR, which are multiple functional layers provided between the first electrode EL1 and the second electrode EL2, in addition to the emitting layer EML.

[0050] Fig. 2 is a cross-sectional view of an organic electroluminescent device 10 according to 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, unlike Fig. 1. Fig. 3 is a cross-sectional view of an organic electroluminescent device 10 according to 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, unlike Fig. 1. Fig. 4 is a cross-sectional view of an organic electroluminescent device 10 according to an embodiment, in which a capping layer CPL is provided on the second electrode EL2, unlike Fig. 2.

[0051] The first electrode EL1 has conductivity. The first electrode EL1 is made of a metal alloy or a conductive compound. The first electrode EL1 is an anode. Also, the first electrode EL1 is a pixel electrode. The first electrode EL1 is a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. If the first electrode EL1 is a transmissive electrode, the first electrode EL1 includes a transparent metal oxide, for example, ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), ITZO (indium tin zinc oxide), etc. If the first electrode EL1 is a semi-transmissive electrode or a reflective electrode, the first electrode EL1 includes Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture thereof (for example, an alloy of Ag and Mg). The first electrode EL1 may have a multi-layer structure including a reflective film or semi-transparent film made of the above-mentioned material, and a transparent conductive film made of ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), ITZO (indium tin zinc oxide), etc. For example, the first electrode EL1 may have a triple-layer structure of ITO / Ag / ITO, but is not limited thereto. The thickness of the first electrode EL1 is about 100 nm to about 1000 nm, for example, about 100 nm to about 300 nm.

[0052] The hole transport region HTR is provided on the first electrode EL1. The hole transport region HTR includes at least one of a hole injection layer HIL, a hole transport layer HTL, a hole buffer layer (not shown), and an electron blocking layer EBL. The thickness of the hole transport region HTR may be, for example, about 5 nm to about 1500 nm.

[0053] The hole transport region HTR may have a single layer of a single material, a single layer of a plurality of different materials, or a multi-layer structure having a plurality of layers of a plurality of different materials.

[0054] 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 a single layer structure of a hole injection material and a hole transport material. The hole transport region HTR may have a single layer structure of a plurality of different materials, and may have a structure of a hole injection layer HIL / hole transport layer HTL, a hole injection layer HIL / hole transport layer HTL / hole buffer layer (not shown), a hole injection layer HIL / hole buffer layer (not shown), a hole transport layer HTL / hole buffer layer, or a hole injection layer HIL / hole transport layer HTL / electron blocking layer EBL, which are stacked in order from the first electrode EL1, but is not limited thereto.

[0055] The hole transport region HTR can be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and Laser Induced Thermal Imaging (LITI).

[0056] The hole injection layer HTL may be, for example, a phthalocyanine compound such as copper phthalocyanine, DNTPD (N,N'-diphenyl-N,N'-bis-[4-phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine), m-MTDATA (4,4',4"-[tris(3-methylphenyl)phenylamino]triphenylamine), TDATA (4,4',4"-tris(N,N-diphenylamino)triphenylamine), 2-TNATA (4,4',4"-tris{N,-(2-naphthyl)-N-phenylamino}-triphenylamine), PEDOT / PSS (poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfuric acid), polyaniline / poly(4-styrenesulfonate)), PANI / DBSA (polyaniline / dodecylbenzenesulfonic acid), PANI / CSA (polyaniline / camphorsulfonic acid), PANI / PSS ((polyaniline) / poly(4-styrenesulfonate)), NPB (N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine), polyether ketone with triphenylamine (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium [tetrakis(pentafluorophenyl)borate], HAT-CN (dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile), and the like.

[0057] The hole transport layer HTL may include, for example, a carbazole derivative such as N-phenylcarbazole or polyvinylcarbazole, a fluorene derivative, a triphenylamine derivative such as TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine) or TCTA (4,4',4"-tris(N-carbazolyl)triphenylamine), NPB (N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine), TAPC (4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzeneamine]), HMTPD (4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl), or mCP (1,3-bis(N-carbazolyl)benzene).

[0058] The thickness of the hole transport region HTR may be about 5 nm to about 1000 nm, for example, about 10 nm to about 500 nm. The thickness of the hole injection layer HIL may be, for example, about 3 nm to about 100 nm, and the thickness of the hole transport layer HTL may be about 3 nm to about 100 nm. For example, the thickness of the electron blocking layer EBL may be about 1 nm to about 100 nm. If 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-mentioned ranges, sufficient hole transport properties can be obtained without a substantial increase in driving voltage.

[0059] In addition to the above-mentioned materials, the hole transport region HTR may further include a charge generating material to improve conductivity. The charge generating material is uniformly or non-uniformly dispersed in the hole transport region HTR. The charge generating material is, for example, a p-dopant. The p-dopant may be one of, but is not limited to, a quinone derivative, a metal oxide, and a cyano group-containing compound. For example, examples of p-dopants include, but are not limited to, quinone derivatives such as TCNQ (tetracyanoquinodimethane) and F4-TCNQ (2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane), metal oxides such as tungsten oxide, and molybdenum oxide.

[0060] As described above, the hole transport region HTR may further include at least one of a hole buffer layer (not shown) and an electron blocking layer EBL in addition to the hole injection layer HIL and the hole transport layer HTL. The hole buffer layer (not shown) compensates for the resonance distance according to the wavelength of light emitted from the emission layer EML to increase light emission efficiency. The material contained in the hole buffer layer (not shown) may be a material that may be contained in the hole transport region HTR. The electron blocking layer EBL is a layer that serves to prevent the injection of electrons from the electron transport region ETR to the hole transport region HTR.

[0061] The light-emitting layer EML is provided on the hole transport region HTR. The light-emitting layer EML has a thickness of, for example, about 10 nm to about 100 nm, or about 10 nm to about 40 nm. The light-emitting layer EML has a multilayer structure having a single layer made of a single material, a single layer made of multiple different materials, or multiple layers made of multiple different materials.

[0062] In the organic electroluminescent device 10 according to an embodiment, the light-emitting layer EML includes a compound according to an embodiment.

[0063] The emission layer EML of the organic electroluminescent device 10 according to an embodiment includes a compound represented by Chemical Formula 1 according to an embodiment. [ka] ...(chemical formula 1)

[0064] In Chemical Formula 1, X 1 ~X 4 are each independently CR a That is, the compound according to one embodiment of the present invention represented by Chemical Formula 1 includes a fused ring in the form of a benzofuran fused to a benzoxazole.

[0065] X 1 ~X 4 CR a If so, multiple R a are each 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, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having from 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having from 2 to 30 ring carbon atoms. a may combine with adjacent groups to form a ring. For example, CR a In R a may be, but is not limited to, a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 20 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 20 ring carbon atoms.

[0066] X 1 ~X 4 CR a In the above, multiple R a may be the same, or at least one may be different from the others. a R a may be bonded to each other to form a hydrocarbon ring or a hetero ring.

[0067] In Chemical Formula 1, L is a substituted or unsubstituted arylene group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 30 ring carbon atoms.

[0068] L is a substituted or unsubstituted phenylene group or a substituted or unsubstituted pyridylene group. For example, in Chemical Formula 1, L is represented by the following L-1 or L-2. [ka]

[0069] In the compound according to one embodiment represented by Chemical Formula 1, Ar is a substituted or unsubstituted hydrocarbon ring group having from 6 to 30 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having from 2 to 30 ring carbon atoms. For example, Ar is a substituted or unsubstituted aryl group having from 6 to 20 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having from 2 to 20 ring carbon atoms. Ar may be an unsubstituted aryl group having from 6 to 20 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having from 2 to 20 ring carbon atoms and containing at least one of N, O, and B as a ring atom.

[0070] In Chemical Formula 1, n is 1 or 2. That is, in one embodiment of the compound represented by Chemical Formula 1, one or two Ar are bonded to the linker L. On the other hand, when n is 2, the two Ar bonded to the linker may be the same or different from each other.

[0071] The compound according to one embodiment has a structure in which a fused ring moiety in the form of benzofuran fused to benzoxazole and a hydrocarbon ring or heterocycle represented by "Ar" are linked to each other via a linker.

[0072] The fused ring moiety where benzofuran is fused to benzoxazole is an electron acceptor. In one embodiment, the compound has a DA (electron donor-electron acceptor) type structure. In this case, in the compound represented by Chemical Formula 1, the "Ar" moiety can be an electron donor. Meanwhile, in the compound represented by Chemical Formula 1, if n is 2, the compound according to one embodiment includes one electron acceptor and two electron donors.

[0073] For example, if Ar is a substituted or unsubstituted aryl group, Ar may be a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted biphenylyl group, a triphenylenyl group, etc. However, the present embodiment is not limited thereto.

[0074] In addition, when Ar is a substituted or unsubstituted heteroaryl group, Ar may be a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzofuranyl group, etc. However, the present embodiment is not limited thereto.

[0075] Ar may be represented by the following formula 2: [ka] ...(chemical formula 2)

[0076] In formula 2, Y is N or B, and Z is a single bond, O, S, or NR d , or CR e R f In Chemical Formula 2, b and c are each independently an integer of 0 to 4.

[0077] In addition, in Chemical Formula 2, R b ~R f are each 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, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having from 6 to 30 ring carbon atoms, or an unsubstituted heteroaryl group having from 2 to 30 ring carbon atoms. b ~R f may be bonded to adjacent groups to form a ring.

[0078] If b is an integer of 2 or more, multiple R b may be the same or at least one may be different. In addition, when c is an integer of 2 or more, multiple R c may be the same, or at least one may be different.

[0079] R b ~R f When adjacent groups are bonded to each other to form a ring, R b ~R f Adjacent substituents among these may be bonded to each other to form a hydrocarbon ring or a hetero ring. In addition, the ring formed by bonding adjacent substituents to each other may be condensed with the hydrocarbon ring or hetero ring of Ar.

[0080] Ar represented by Chemical Formula 2 may be represented by the following Chemical Formula 2-1 or Chemical Formula 2-2. [ka] ...(chemical formula 2-1) [ka] ...(Chemical formula 2-2)

[0081] In Chemical Formula 2-1 to Chemical Formula 2-2, Z and R b , R cWith respect to a, b, and c, the same applies as explained in Chemical Formula 2 above.

[0082] Chemical formula 2-2 may be represented by any one of the following chemical formulas 2-2A to 2-2E. [ka] ...(chemical formula 2-2A) [ka] ...(Chemical formula 2-2B) [ka] ...(chemical formula 2-2C) [ka] ...(chemical formula 2-2D) [ka] ...(chemical formula 2-2E)

[0083] In Chemical Formula 2-E, b1 is an integer of 0 to 3, and b2 is an integer of 0 to 4. b1 and R b2 are each 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, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having from 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having from 2 to 30 ring carbon atoms. b1 and R b2 may each be bonded to an adjacent group to form a ring.

[0084] In Chemical Formula 2-2A to Chemical Formula 2-2E, R b , R c With respect to a, b, and c, the same applies as explained in Chemical Formula 2 above.

[0085] Chemical formula 1 may be represented by the following Chemical formula 1-1. [ka] ...(chemical formula 1-1)

[0086] In Chemical Formula 1-1, L, n, and Ar are the same as those described in Chemical Formula 1 above.

[0087] In the compound represented by Chemical Formula 1 according to an embodiment, for example, when "Ar" is represented by Chemical Formula 2-2, the compound according to an embodiment is a DA-type delayed fluorescent light-emitting material. The compound according to an embodiment is a DA-type thermally activated delayed fluorescent (TADF) light-emitting material, in which the fused ring moiety in which benzofuran is fused to benzoxazole is an electron acceptor moiety, and the moiety represented by Chemical Formula 2-2 is an electron donor moiety.

[0088] The compound according to the embodiment may be any one of the compounds shown in the following first compound group. The organic electroluminescent device 10 according to the embodiment may include at least one compound among the compounds shown in the first compound group in the emission layer EML.

[0089] [First compound group] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka]

[0090] The compound according to one embodiment has a central emission wavelength (λ ) in the wavelength region of 420 nm or more. max For example, the compound according to one embodiment represented by Chemical Formula 1 is a light-emitting material having a central emission wavelength in the wavelength range of 420 nm to 470 nm, or a light-emitting material having a central emission wavelength in the wavelength range of 500 nm to 500 nm. The compound according to one embodiment represented by Chemical Formula 1 is a blue dopant or a green dopant.

[0091] In the organic electroluminescent device 10 according to an embodiment, the emission layer EML includes a host and a dopant, and includes the compound according to the embodiment described above as a dopant. For example, in the organic electroluminescent device 10 according to an embodiment, the emission layer EML may include the compound according to the embodiment described above as a delayed fluorescent dopant.

[0092] The compound according to one embodiment of the present invention represented by Chemical Formula 1 has an absolute value of the difference between the lowest excited singlet energy level (S1) and the lowest excited triplet energy level (T1) (ΔE ST ) is 0.2 eV or less and is used as a thermally activated delayed fluorescence dopant. Thus, in the organic electroluminescent device 10 according to one embodiment, the emission layer EML contains at least one of the above-mentioned compounds as a thermally activated delayed fluorescence (TADF) dopant, and the emission layer EML emits delayed fluorescence. For example, the emission layer EML may emit thermally activated delayed fluorescence.

[0093] The compound according to an embodiment has a novel compound structure including a composite ring in which benzoxazole is condensed with benzofuran as an electron acceptor, and is used as a thermally activated delayed fluorescent light-emitting material. The compound according to an embodiment is used as an emission layer material of an organic electroluminescent device to improve the luminous efficiency of the organic electroluminescent device and increase its lifespan. In particular, the compound according to an embodiment is used as an emission material that emits light in the blue or green wavelength region, and shows excellent luminous efficiency.

[0094] In one embodiment, the emitting layer EML is a delayed fluorescent emitting layer, and the emitting layer MEL includes a known host material and the compound according to the embodiment described above. For example, in one embodiment, the emitting layer EML includes the compound according to the embodiment as a dopant material, and Alq 3 (tris(8-hydroxyquinolino)aluminum), CBP (4,4'-bis(N-carbazolyl)-1,1'-biphenyl), PVK (poly(n-vinylcarbazole), ADN (9,10-di(naphthalen-2-yl)anthracene), TCTA (4,4',4"-tris(carbazol-9-yl)-triphenylamine), TPBi (1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene), TBADN (3-tert-butyl 4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl), MADN (2-methyl-9,10-bis(naphthalen-2-yl)anthracene), DPEPO (bis[2-(diphenylphosphino)phenyl]ether oxide), CP1 (hexaphenylcyclotriphosphazene), UGH2 (1,4-bis(triphenylsilyl)benzene), DPSiO 3 (Hexaphenylcyclotrisiloxane), DPSiO 4(octaphenylcyclotetrasiloxane), or PPF (2,8-bis(diphenylphosphoryl)dibenzofuran), mCBP (3,3'-bis(N-carbazolyl)-1,1'-biphenyl), mCP (1,3-bis(N-carbazolyl)benzene), etc. However, the present embodiment is not limited to these, and may further include a known delayed fluorescent host material in addition to the above-mentioned host materials.

[0095] The embodiment of the present disclosure is not limited thereto, and the compound according to the embodiment described above may be used as a host material for the emitting layer EML. When the compound according to the embodiment is used as a host material, a known dopant material may be used in the emitting layer EML in addition to the compound according to the embodiment.

[0096] In the organic electroluminescent device 10 according to an embodiment, the emission layer EML may be formed of a known dopant material such as a styryl derivative (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4′-[(di-p-tolylamino)styryl]stilbene (DPAVB), N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalene-2-yl)bis(2-phenylene)-1,1-diyl)phenyl ... (N-BDAVBi), perylene and its derivatives (e.g., 2,5,8,11-tetra-t-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1-dipyrene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene), 4-CzIPN (1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene), and the like.

[0097] When the emitting layer EML emits blue light, the emitting layer EML may further include a fluorescent material including any one selected from the group consisting of spiro-DPVBi, spiro-6P, DSB (distyryl-benzene), DSA (distyryl-arylene), PFO (polyfluorene)-based polymers, and PPV (poly(p-phenylenevinylene)-based polymers. When the emitting layer EML emits blue light, for example, the emitting layer EML includes the compound according to an embodiment as a host material and (4,6-F 2 ppy) 2 These may include metal complexes such as Irpic, or organometallic complexes, and perylene and its derivatives.

[0098] When the emitting layer EML emits green light, the emitting layer EML is, for example, Alq 3 In the case where the light emitting layer emits green light, for example, the light emitting layer EML contains the compound according to one embodiment as a host material and Ir(ppy) as a known dopant material. 3 These may include metal complexes or organometallic complexes such as (fac-tris(2-phenylpyridine)iridium), coumarin and its derivatives, and the like.

[0099] Meanwhile, although not shown, the organic electroluminescent device 10 according to an embodiment may include a plurality of light-emitting layers. The plurality of light-emitting layers may be sequentially stacked, and for example, the organic electroluminescent device 10 including the plurality of light-emitting layers may emit white light. The organic electroluminescent device 10 including the plurality of light-emitting layers is an organic electroluminescent device having a tandem structure. When the organic electroluminescent device 10 includes a plurality of light-emitting layers, at least one of the light-emitting layers EML includes the compound according to the embodiment described above.

[0100] 1 to 4, the electron transport region ETR is provided on the emission layer EML. The electron transport region ETR includes at least one of a hole blocking layer HBL, an electron transport layer ETL, and an electron injection layer EIL, but the present embodiment is not limited thereto.

[0101] The electron transport region ETR has a single layer made of a single material, a single layer made of a plurality of different materials, or a multilayer structure having a plurality of layers made of a plurality of different materials.

[0102] 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 made of an electron injection material and an electron transport material. The electron transport region ETR may have a single layer structure made of a plurality of different materials, and may have a structure of an electron transport layer ETL / electron injection layer EIL or a hole blocking layer HBL / electron transport layer ETL / electron injection layer EIL stacked in order from the light emitting layer EML, but is not limited thereto. The thickness of the electron transport region ETR may be, for example, about 30 nm to about 150 nm.

[0103] The electron transport region ETR can be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0104] When the electron transport region ETR includes the electron transport layer ETL, the electron transport region ETR includes an anthracene-based compound. However, the electron transport region is not limited thereto, and may include, for example, Alq 3(Tris(8-hydroxyquinolinato)aluminum), 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, 2,4,6-tris(3'-pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, TPBi(1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene), BCP(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bph en (4,7-diphenyl-1,10-phenanthroline), TAZ (3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), NTAZ (4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), tBu-PBD (2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq (bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-olato)aluminum), Bebq 2 (beryllium bis(benzoquinoline-10-olate), ADN (9,10-di(naphthalen-2-yl)anthracene), BmPyPhB (1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene), and mixtures thereof. The electron transport layer ETL has a thickness of about 10 nm to about 100 nm, for example, about 15 nm to about 50 nm. When the thickness of the electron transport layer HTL satisfies the above-mentioned range, sufficient electron transport properties can be obtained without a substantial increase in driving voltage.

[0105] When the electron transport region ETR includes an electron injection layer EIL, the electron transport region ETR may be a metal halide such as LiF, NaCl, CsF, RbCl, or RbI, a lanthanide metal such as Yb, or Li 2Metal oxides such as O, BaO, or LiQ (lithium quinolate) may be used, but are not limited thereto. The electron injection layer EIL may be made of a material in which an electron transport material and an insulating organo metal salt are mixed. The organo metal salt is a material having an energy band gap of about 4 eV or more. For example, the organo metal salt includes metal acetate, metal benzoate, metal acetoacetate, metal acetylacetonate, or metal stearate. The thickness of the electron injection layer EIL is about 0.1 nm to about 10 nm, or about 0.3 nm to about 9 nm. When the thickness of the electron injection layer EIL satisfies the above-mentioned range, sufficient electron injection characteristics can be obtained without a substantial increase in driving voltage.

[0106] The electron transport region ETR may include a hole blocking layer HBL as described above. The hole blocking layer HBL may include at least one of, for example, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and Bphen (4,7-diphenyl-1,10-phenanthroline), but is not limited thereto.

[0107] The second electrode EL2 is provided on the electron transport region ETR. The second electrode EL2 is a common electrode or a cathode. The second electrode EL2 is a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. If the second electrode EL2 is a transmissive electrode, the second electrode EL2 is made of a transparent metal oxide, for example, ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), ITZO (indium tin zinc oxide), or the like. If the second electrode EL2 is a semi-transmissive electrode or a reflective electrode, the second electrode EL2 includes Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture containing these (for example, an alloy of Ag and Mg). The second electrode EL2 may have a multi-layer structure including a reflective film or semi-transparent film made of the above-mentioned material, and a transparent conductive film made of ITO, IZO, ZnO, ITZO, or the like.

[0108] Although not shown, 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 can be reduced.

[0109] A capping layer CPL may be further provided on the second electrode EL2 of the organic electroluminescent device 10 according to the embodiment. The capping layer CPL may be, for example, α-NPD, NPB, TPD, m-MTDATA, Alq 3 , CuPc, TPD15 (N4,N4,N4',N4'-tetra(biphenyl-4-yl)biphenyl-4,4'-diamine), TCTA (4,4',4"-tris(carbazol-9-yl)triphenylamine), N,N'-bis(naphthalen-1-yl), and the like.

[0110] The organic electroluminescent device 10 according to an embodiment of the present invention exhibits improved luminous efficiency by including the compound according to the embodiment in the emission layer EML disposed between the first electrode EL1 and the second electrode EL2. The compound according to the embodiment is a thermally activated delayed fluorescence dopant, and the emission layer EML includes the compound according to the embodiment and emits thermally activated delayed fluorescence, thereby exhibiting good luminous efficiency characteristics. In particular, the compound according to the embodiment is used as a dopant material for the emission layer EML to realize an organic electroluminescent device having excellent luminous efficiency and long life characteristics in the green or blue emission region.

[0111] In addition, the compound according to an embodiment may be included and used as a host material in the emission layer EML, or may be used as a known fluorescent dopant material or a known phosphorescent dopant material to improve the luminous efficiency and lifetime of an organic electroluminescent device.

[0112] Meanwhile, the compound according to the embodiment described above may be included in an organic layer other than the emission 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 invention may include the compound described above in at least one functional layer disposed between the first electrode EL1 and the second electrode EL2, or in a capping layer CPL disposed on the second electrode EL2.

[0113] The compound according to the embodiment has a novel compound structure including a fused ring in which benzoxazole is fused with benzofuran as an electron acceptor, and is used as an emission layer material to contribute to high efficiency characteristics of an organic electroluminescent device. In addition, an organic electroluminescent device according to the embodiment including the compound according to the embodiment in an emission layer exhibits high efficiency characteristics in a green emission wavelength region or a blue emission wavelength region. EXAMPLES

[0114] Hereinafter, a compound according to an embodiment of the present invention and an organic electroluminescent device according to an embodiment of the present invention will be described in detail with reference to examples and comparative examples. Note that the following examples are merely illustrative examples for aiding in understanding the present invention, and the scope of the present invention is not limited thereto.

[0115] 1. Synthesis of Compounds According to an Embodiment First, the synthesis method of the compound according to the present embodiment will be specifically described by taking as examples the synthesis methods of compounds 1, 3, 5, 30, 34, 52, 55, and 56. The synthesis methods of the compounds described below are merely examples, and the synthesis methods of the compounds according to the present embodiment are not limited to the following examples.

[0116] (1) Synthesis of Compound 5 Compound 5 according to one embodiment can be synthesized, for example, by the steps of Reaction Scheme 1 below. [Reaction Scheme 1] [ka]

[0117] <Synthesis of intermediate 1> 30.0g (140.7mmol) of 2-methoxydibenzofuran-3-amine and 703mL of dichloromethane were placed in a 3000mL one-neck flask and cooled to 0℃. 105.7g (422.08mmol) of boron tribromide was diluted in 422mL of dichloromethane, and boron tribromide (1.0M DCM solution) was added slowly at 0℃. The mixture was stirred at 0℃ for 1 hour and then at room temperature for 4 hours. After the reaction was completed, the mixture was cooled to 0℃ and 300mL of distilled water was added slowly. 2 CO 3 80.0 g (578.0 mmol) of the above was dissolved in 289 mL of distilled water, and the mixture was gradually added at 0°C to adjust the pH to 7-8, and then stirred at 0°C for a day. The precipitated solid was washed with distilled water, filtered, and then dried in a vacuum oven for a day. 31.5 g (crude product) of a gray solid compound (intermediate 1) was obtained. (The next reaction was carried out without further purification.)

[0118] <Synthesis of intermediate 2> In a 1000mL one-neck flask, 12.8g (64.3mmol) of intermediate 1, 14.3g (77.1mmol) of 3-bromobenzaldehyde, and 321mL of ethanol were added and mixed, and then stirred at room temperature for 3 hours. After the reaction was completed, the precipitated solid was filtered while being washed with ethanol. 19.0g (yield: 80.7%) of a yellow solid compound (intermediate 2) was obtained.

[0119] <Synthesis of intermediate 3> In a 1000mL one-neck flask, 19.0g (51.8mmol) of intermediate 2 and 517mL of dichloromethane were added and stirred at room temperature. 14.1g (62.1mmol) of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) was gradually added and stirred at room temperature for one day. After the reaction was completed, the mixture was passed through a Celite pad using hot chloroform, and the solvent was removed using reduced pressure distillation. The resulting compound was slurried using chloroform and methanol, and then filtered with methanol. 17.6g (yield: 93.36%) of a beige solid compound (intermediate 3) was obtained as a solid.

[0120] <Synthesis of compound 5> In a 250 mL one-neck flask, add 1.6 g (4.5 mmol) of intermediate 3, 1.5 g (9.0 mmol) of 9H-carbazole, and Pd(dba). 2 0.3g (0.5mmol), P(t-Bu) 3 0.26 g (0.5 mmol, 50 wt% toluene solution), 1.5 g (15.8 mmol) of NaOtBu, and 45 mL of xylene were added, and the mixture was refluxed and stirred for a day. After cooling to room temperature, impurities were removed by celite filtration. After the solvent was completely removed, the mixture was purified by silica gel column chromatography (MC:HEX=1:8→1:1). The solid thus obtained was solidified with (acetone:MeOH=2:1) ​​and then filtered to obtain 1.44 g (yield: 71%) of compound 5 as an ocher solid. The molecular weight of compound 5 measured by FAB-MS was MS[M+H] + =451.

[0121] (2) Synthesis of compound 30 Compound 30 according to one embodiment can be synthesized, for example, by the steps of Reaction Scheme 2 below. [Reaction Scheme 2] [ka]

[0122] <Synthesis of intermediate 4> In a 1000mL one-neck flask, 12.8g (64.3mmol) of intermediate 1, 14.3g (77.1mmol) of 4-bromobenzaldehyde, and 321mL of ethanol were mixed and stirred at room temperature for 3 hours. After the reaction was completed, the precipitated solid was filtered while being washed with ethanol. 18.5g (yield: 79.1%) of a yellow solid compound (intermediate 4) was obtained.

[0123] <Synthesis of intermediate 5> In a 1000mL one-neck flask, 18.5g (50.8mmol) of intermediate 4 and 517mL of dichloromethane were added and stirred at room temperature. 14.1g (62.1mmol) of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) was gradually added and stirred at room temperature for one day. After the reaction was completed, the mixture was passed through a Celite pad using hot chloroform, and the solvent was removed using reduced pressure distillation. The resulting compound was made into a slurry using chloroform and methanol, and then filtered with methanol. 16.8g (yield: 91.1%) of a beige solid compound (intermediate 5) was obtained.

[0124] <Synthesis of compound 30> In a 250 mL single-neck flask, add 1.6 g (4.5 mmol) of intermediate 5, 1.9 g (9.1 mmol) of 9,9-dimethyl-9,10-dihydroacridine, and Pd(dba) 2 0.3g (0.5mmol), P(t-Bu) 30.26 g (0.5 mmol, 50 wt% toluene solution), 1.5 g (15.8 mmol) of NaOtBu, and 45 mL of xylene were added, and the mixture was refluxed and stirred for a day. After cooling to room temperature, impurities were removed by celite filtration. After the solvent was completely removed, the mixture was purified by silica gel column chromatography (MC:HEX=1:8→1:1). The product thus obtained was solidified with (acetone:MeOH=2:1) ​​and filtered to obtain 1.66 g (yield: 75%) of compound 30 as an ocher solid. The molecular weight of compound 30 measured by FAB-MS measurement was MS[M+H] + =493.

[0125] (3) Synthesis of compound 34 Compound 34 according to one embodiment can be synthesized, for example, by the steps of Reaction Scheme 3 below. [Reaction Scheme 3] [ka]

[0126] In a 250 mL one-neck flask, add 1.6 g (4.5 mmol) of intermediate 3, 1.65 g (9.0 mmol) of 10H-phenoxazine, and Pd(dba). 2 0.3g (0.5mmol), P(t-Bu) 3 0.26 g (0.5 mmol, 50 wt% toluene solution), 1.5 g (15.8 mmol) of NaOtBu, and 45 mL of xylene were added, and the mixture was refluxed and stirred for a day. Then, after cooling to room temperature, impurities were removed by celite filtration. After the solvent was completely removed, the mixture was purified by silica gel column chromatography (MC:HEX=1:8→1:1). The product thus obtained was solidified with (acetone:MeOH=2:1) ​​and filtered to obtain 1.51 g (yield: 72%) of compound 34 as an ocher solid. The molecular weight of compound 34 measured by FAB-MS measurement was MS[M+H] + =467.

[0127] (4) Synthesis of compound 52 Compound 52 according to one embodiment can be synthesized, for example, by the steps of Reaction Scheme 4 below. [Reaction Scheme 4] [ka]

[0128] <Synthesis of intermediate 6> In a 2000 mL one-neck flask, 31.5 g (158.1 mmol) of intermediate 1, 62.5 g (237.2 mmol) of 3,5-dibromobenzaldehyde, and 1054 mL of ethanol were added and mixed, and then stirred at 90° C. for 4 hours. After the reaction was completed, the mixture was cooled to room temperature. The precipitated solid was filtered while being washed with ethanol. 42.1 g (yield: 60.0%) of a brown solid compound (intermediate 6) was obtained.

[0129] <Synthesis of intermediate 7> In a 2000mL one-neck flask, 42.05g (94.4mmol) of intermediate 6 and 765mL of dichloromethane were added and stirred at room temperature. 31.3g (137.78mmol) of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) was gradually added and stirred at 40°C for 3 hours. After the reaction was completed, the mixture was passed through a Celite pad using hot chloroform, and the solvent was removed using reduced pressure distillation. The obtained compound was slurried using 50mL of chloroform and 500mL of methanol, and 33.4g (yield: 79.8%) of a beige solid compound (intermediate 7) was obtained.

[0130] <Synthesis of compound 52> In a 250 mL single-neck flask, add 3.0 g (6.8 mmol) of intermediate 7, 2.5 g (13.9 mmol) of phenoxazine, and Pd(dba). 20.4g (0.68mmol), 0.4mL (1.0mmol) of S-phos, 2.0g (20.3mmol) of NaOtBu, and 45mL of xylene were added, and the mixture was refluxed and stirred for 30 minutes. Next, after cooling to room temperature, methanol was added to solidify. After filtration, the solid was heated and dissolved in chloroform, and then purified by silica gel column chromatography (CHCl3:HEX=1.4→2:1). A small amount of acetone was added to the sufficiently cooled product to solidify it, and then filtered to obtain 1.9g (yield: 44.2%) of yellow solid compound 52. The molecular weight of compound 52 measured by FAB-MS measurement was MS[M+H] + =648.

[0131] (5) Synthesis of compound 55 Compound 55 according to one embodiment can be synthesized, for example, by the steps of Reaction Scheme 5 below. [Reaction Scheme 5] [ka]

[0132] In a 250 mL one-neck flask, add 1.6 g (4.5 mmol) of intermediate 3, 3.0 g (9.0 mmol) of N,N-diphenyl-9H-carbazol-2-amine, and Pd(dba) 2 0.3g (0.5mmol), P(t-Bu) 3 0.26 g (0.5 mmol, 50 wt% toluene solution), 1.5 g (15.8 mmol) of NaOtBu, and 45 mL of xylene were added, and the mixture was refluxed and stirred for a day. After cooling to room temperature, impurities were removed by celite filtration. After the solvent was completely removed, the mixture was purified by silica gel column chromatography (MC:HEX=1:8→1:1). The product thus obtained was solidified with (acetone:MeOH=2:1) ​​and filtered to obtain 2.0 g (yield: 71.2%) of compound 55 as an ocher solid. The molecular weight of compound 55 measured by FAB-MS was MS[M+H] + =618.

[0133] (6) Synthesis of compound 56 Compound 56 according to one embodiment can be synthesized, for example, by the steps of Reaction Scheme 6 below. [Reaction Scheme 6] [ka]

[0134] In a 250 mL one-neck flask, add 2.0 g (4.5 mmol) of intermediate 7, 3.0 g (9.0 mmol) of N,N-diphenyl-9H-carbazol-2-amine, and Pd(dba). 2 0.3g (0.5mmol), P(t-Bu) 3 0.26 g (0.5 mmol, 50 wt% toluene solution), 1.5 g (15.8 mmol) of NaOtBu, and 45 mL of xylene were added, and the mixture was refluxed and stirred for a day. After cooling to room temperature, impurities were removed by celite filtration. After the solvent was completely removed, the mixture was purified by silica gel column chromatography (MC:HEX 1:8 = → 1:1). The product thus obtained was solidified with (acetone:MeOH = 2:1) and filtered to obtain 2.66 g (yield: 61.6%) of compound 56 as an ocher solid. The molecular weight of compound 56 measured by FAB-MS measurement was MS [M + H] + =950.

[0135] (7) Synthesis of Compound 1 Compound 1 according to one embodiment can be synthesized, for example, by the steps of Reaction Scheme 7 below. [Reaction Scheme 7] [ka]

[0136] In a 250 mL one-neck flask, 1.6 g (4.5 mmol) of intermediate 3, 1.0 g (6.0 mmol) of 1-naphthalenylboronic acid, and 100 mL of toluene were refluxed and stirred for a day using a Dean-Stark apparatus. After cooling, the solvent was completely removed and the mixture was purified by silica gel column chromatography (MC:HEX=1:4) to obtain 1.70 g (yield: 92.0%) of white solid compound 1. The molecular weight of compound 1 measured by FAB-MS was MS[M+H] + =412.

[0137] (8) Synthesis of compound 3 Compound 3 according to one embodiment can be synthesized, for example, by the steps of Reaction Scheme 8 below. [Reaction Scheme 8] [ka]

[0138] In a 250 mL one-neck flask, 1.6 g (4.5 mmol) of intermediate 3, 1.6 g (6.0 mmol) of 2-triphenylenylboronic acid, and 100 mL of toluene were added and mixed, and the mixture was refluxed and stirred for a day using a Dean-Stark apparatus. After cooling, the solvent was completely removed, and the mixture was purified by silica gel column chromatography (MC:HEX=1:4) to obtain 1.91 g (yield: 88.3%) of white solid compound 3. The molecular weight of compound 3 measured by FAB-MS measurement was MS[M+H] + =512.

[0139] 2. Compound Evaluation The fluorescent emission characteristics of the compound according to one embodiment were evaluated. The emission characteristics of the comparative compounds were evaluated together with the compound according to one embodiment. The compounds used for the evaluation are shown below.

[0140] (Compounds used in evaluating luminescence properties) [ka]

[0141] (Comparative Example Compound Used for Evaluating Light Emitting Properties) [ka]

[0142] Table 1 shows the ΔE ST The characteristic evaluation results are shown in Table 1. ΔE ST is the difference between the lowest singlet excitation energy level (S1 level) and the lowest triplet excitation energy level (T1 level), and was calculated using Gaussian calculation (basis set B3LYP / 6-31G*). The emission wavelengths of the example compounds and the comparative compounds were confirmed using emission spectra. [Table 1]

[0143] Referring to the results in Table 1, the compound according to one embodiment can be used as a light-emitting material that emits blue or green light. Compounds 30, 34, 52, 55, 56, etc. have a small ΔE of 0.02 eV or less. ST It is believed that the compound has a value and can be used as a delayed fluorescent material.

[0144] 3. Preparation and evaluation of organic electroluminescence devices 3-1. Example A of an organic electroluminescent device including a compound according to an embodiment An organic electroluminescent device according to an embodiment including a compound according to an embodiment as a host material of an emission layer was manufactured by the following method.

[0145] (Fabrication of Organic Electroluminescent Device) The ITO-patterned glass substrate was washed with ultrapure water and ultrasonically cleaned, then irradiated with UV for 30 minutes and then treated with ozone. Next, HT1 was evaporated to a thickness of 120 nm, and HT2 was evaporated to a thickness of 10 nm to form the hole transport region.

[0146] Next, when forming the light-emitting layer, the compound according to one embodiment or the comparative compound and 4CzIPN were co-deposited in a ratio of 80:20 to form a layer having a thickness of 40 nm. That is, in the light-emitting layer formed by co-deposition, the example compound was mixed with 4CzIPN and deposited in each of the examples, and the comparative compound was mixed with 4CzIPN and deposited in each of the comparative examples.

[0147] Next, a 30 nm thick layer was formed on the emissive layer by vapor deposition of a 5:5 mixture of ET and Liq, and a 1 nm thick layer of Liq was formed on the emissive layer. A 10 nm thick second electrode was then formed with Mg:Ag (10:1).

[0148] In the examples, the hole transport region, the light emitting layer, the electron transport region, and the second electrode were formed using a vacuum deposition apparatus. The hole transport region materials, the electron transport region materials, and the dopant materials used in the preparation of the organic electroluminescent device are shown below. [ka] [ka]

[0149] (Evaluation of the characteristics of organic electroluminescent devices) Table 2 shows a comparison of the efficiency, lifetime, and luminescent color of the fabricated organic electroluminescent devices. In the characteristic evaluation results for the examples and comparative examples shown in Table 2, the efficiency was 2 In the evaluation of the characteristics of the organic electroluminescent device, the efficiency and lifetime of the examples are shown as relative values ​​when the efficiency and lifetime of Comparative Example 1-1 are set to 100%.

[0150] In Example 1-1 and Comparative Example 1-2, Compound 1 and Compound 3 are used as the host material of the light-emitting layer, respectively. In Comparative Example 1-1, mCBP, which is a known host material, is used as the host material of the light-emitting layer. [Table 2]

[0151] Referring to the results in Table 2, it can be seen that Examples 1-1, 1-2, and Comparative Example 1-1 all emit light in the green wavelength region. Example 1-1 shows a slightly decreased efficiency compared to Comparative Example 1-1, but shows improved life characteristics. Also, it can be seen that Example 1-2 shows both improved efficiency and life characteristics compared to Comparative Example 1-1. Therefore, it can be seen that the compound according to one embodiment can be used as a host material for an emitting layer that emits light in the green wavelength region, and exhibits superior lifetime characteristics compared to the case of using conventional host materials.

[0152] 3-2. Example B of an organic electroluminescent device including a compound according to an embodiment An organic electroluminescent device according to an embodiment, which contains the compound according to an embodiment as a dopant material in the light-emitting layer, was produced by the following method.

[0153] (Fabrication of Organic Electroluminescent Device) The ITO-patterned glass substrate was washed with ultrapure water and ultrasonically cleaned, then irradiated with UV for 30 minutes and then treated with ozone. Next, HT1 was evaporated to a thickness of 120 nm, and HT2 was evaporated to a thickness of 10 nm to form a hole transport region.

[0154] Next, when forming the light-emitting layer, the compound according to one embodiment or the comparative compound and mCBP were co-deposited in a ratio of 20:80 to form a layer having a thickness of 40 nm. That is, in the light-emitting layer formed by co-deposition, the compound according to the present invention was mixed with mCBP and deposited in the examples, and the comparative compound was mixed with mCBP and deposited in the comparative examples.

[0155] Next, a 30 nm thick layer was formed on the emissive layer by vapor deposition of a 5:5 mixture of ET and Liq, and a 1 nm thick layer of Liq was formed on the emissive layer to form the electron transport region. A 10 nm thick second electrode was then formed with Mg:Ag (10:1).

[0156] In the examples, the hole transport region, the light emitting layer, the electron transport region, and the second electrode were formed using a vacuum deposition apparatus.

[0157] (Evaluation of the characteristics of organic electroluminescent devices) Table 3 shows a comparison of the efficiency, lifetime, and luminescent color of the fabricated organic electroluminescent devices. In the characteristic evaluation results for the examples and comparative examples shown in Table 3, the efficiency was 2 In addition, in the evaluation of the characteristics of the organic electroluminescent device, the efficiency and lifetime of the examples are shown as relative values ​​when the efficiency and lifetime of Comparative Example 2-1 or Comparative Example 3-1 are set to 100%.

[0158] In the evaluations shown in Table 3 below, Examples 2-1, 2-2, and Comparative Example 2-1 show the evaluation results of organic electroluminescent devices that emit 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 that emit light in the green wavelength region. In Examples 2-1, 2-2, and Comparative Example 2-1, Examples 3-1 to 3-4, and Comparative Example 3-1, mCBP, a known host material, is used as the host material of the light-emitting layer. [Table 3]

[0159] Referring to the results in Table 3, it can be seen that the examples are organic electroluminescent devices that emit blue or green light, and the compound according to one embodiment can be used as a blue dopant that emits blue light or a green dopant that emits green light.

[0160] Furthermore, referring to the results in Table 3, it can be seen that Examples 2-1 and 2-2 show improved efficiency characteristics and long life characteristics compared to Comparative Example 2-1, and Examples 3-1 to 3-4 show improved efficiency characteristics and long life characteristics compared to Comparative Example 3-1.

[0161] Therefore, referring to the evaluation results in Table 3, it can be seen that the compound according to an embodiment emits blue or green light when used as an emission layer dopant of an organic electroluminescent device. In addition, unlike the comparative example compound, the compound according to an embodiment includes a structure in which benzofuran is condensed with benzoxazole, and when used as an emission layer dopant material, it can be seen that there is an effect of improving the efficiency and life characteristics of an organic electroluminescent device.

[0162] The compound according to an embodiment has a novel compound structure including a fused ring in which benzofuran and benzoxazole are fused as an electron acceptor, and is used as an emission layer material to contribute to high efficiency and long life characteristics of an organic electroluminescent device. In addition, an organic electroluminescent device according to an embodiment including the compound according to an embodiment in an emission layer exhibits good efficiency characteristics and excellent life characteristics in a green emission wavelength region or a blue emission wavelength region.

[0163] Although the present invention has been described above with reference to preferred embodiments, it should be understood that a person skilled in the art or having ordinary knowledge in the art can make various modifications and variations to the present invention without departing from the spirit and technical scope of the present invention as set forth in the claims below.

[0164] Therefore, the technical scope of the present invention should be determined not by the contents described in the detailed description of the specification, but by the claims. [Explanation of symbols]

[0165] 10: Organic electroluminescent element EL1: First electrode EL2: second electrode HTR: hole transport region EML: Light-emitting layer ETR: Electron transport region

Claims

1. A compound represented by the following chemical formula 1-1. 【Chemistry 1】 ...(Chemical formula 1-1) (In the above Chemical Formula 1, L is a substituted or unsubstituted arylene group having from 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having from 2 to 30 ring carbon atoms, n is 1 or 2; Ar is represented by the following chemical formula 2: 【Chemistry 2】 ...(chemical formula 2) In the above Chemical Formula 2, Y is N or B; Z is a single bond, O, S, NR d , or CR e R f ; b and c each independently represent an integer of 0 to 4, R b to R f each independently represent a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted silyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having from 6 to 30 ring carbon atoms, or an unsubstituted heteroaryl group having from 2 to 30 ring carbon atoms, which are bonded to adjacent groups to form a ring or are not bonded to each other; The term "substituted or unsubstituted" means that the group is unsubstituted or substituted with one or more substituents 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 oxy group, a thio 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 alkoxy group, a hydrocarbon ring group, an aryl group, and a heterocyclic group.

2. The compound according to claim 1, wherein the chemical formula 2 is represented by the following chemical formula 2-1 or 2-2. 【Chemistry 3】 ...(Chemical formula 2-1) 【Chemistry 4】 ...(Chemical formula 2-2)

3. The compound according to claim 2, wherein the chemical formula 2-2 is represented by any one of the following chemical formulas 2-2A to 2-2E. 【Chemistry 5】 ...(Chemical formula 2-2A) 【Chemistry 6】 ...(Chemical formula 2-2B) 【Chemistry 7】 ...(Chemical formula 2-2C) 【Chemistry 8】 ...(Chemical formula 2-2D) 【Chemistry 9】 ...(Chemical formula 2-2E) (In the above Chemical Formula 2-2E, b1 is an integer of 0 to 3, and b2 is an integer of 0 to 4, R ｂ１ and R ｂ２ are each 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, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having from 6 to 30 ring carbon atoms, or an unsubstituted heteroaryl group having from 2 to 30 ring carbon atoms, which are bonded to adjacent groups to form a ring or are not bonded to each other, The term "substituted or unsubstituted" means that the group is unsubstituted or substituted with one or more substituents 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 oxy group, a thio 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 alkoxy group, a hydrocarbon ring group, an aryl group, and a heterocyclic group.

4. The compound according to claim 1 , wherein the compound represented by Chemical Formula 1 is a green dopant that emits green light having a center wavelength of 500 nm to 550 nm.

5. The compound according to claim 1 , wherein the compound represented by Chemical Formula 1 is a blue dopant that emits blue light having a central wavelength of 420 nm to 470 nm.

6. The compound represented by the formula 1 has an absolute value of the difference between the lowest excited singlet energy level (S1) and the lowest excited triplet energy level (T1) (ΔE ＳＴ 2. The compound according to claim 1, wherein the electron transport coefficient is 0.2 eV or less.

7. The compound according to claim 1 , wherein the compound represented by Chemical Formula 1 is any one of the compounds of the following first compound group: [First compound group] 【Chemistry 10】 【Chemistry 11】 【Chemistry 12】 【Chemistry 13】 【Chemistry 14】 【Chemistry 15】 【Chemistry 16】

8. A first electrode; a second electrode provided on the first electrode; An organic electroluminescent device comprising: a light-emitting layer provided between the first electrode and the second electrode, the light-emitting layer comprising the compound according to claim 1 .

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

10. The light-emitting layer comprises a host and a dopant, The organic electroluminescent device according to claim 8 , wherein the host comprises the compound.

11. The light-emitting layer emits delayed fluorescence, The organic electroluminescent device according to claim 8 , wherein the compound is a delayed fluorescent dopant.

12. The organic electroluminescent device according to claim 8 , wherein the light emitting layer emits light having a central wavelength of 500 nm to 550 nm, or light having a central wavelength of 420 nm to 470 nm.

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