Organic electroluminescent device and compound for organic electroluminescent device

Abstract

The present application relates to an organic electroluminescent device and a compound for the organic electroluminescent device, wherein the organic electroluminescent device comprises a first electrode, a second electrode on the first electrode, and an emission layer between the first electrode and the second electrode. The emission layer may comprise the compound, wherein the compound comprises a first phenyl group substituted by at least one cyano group and a second phenyl group substituted by five substituted or unsubstituted carbazole groups, wherein the second phenyl group is directly bonded to the first phenyl group.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] Korean Patent Application No. 10-2018-0141922, filed on November 16, 2018 with the Korean Intellectual Property Office and entitled “ORGANIC ELECTROLUMINESCENT DEVICE AND COMPOUND FOR ORGANIC ELECTROLUMINESCENT DEVICE,” is incorporated herein by reference in its entirety. Technical Field

[0003] Embodiments relate to organic electroluminescent devices and compounds used therein. Background Art

[0004] Recently, the development of organic electroluminescent display devices as image display devices is actively being carried out. Unlike liquid crystal display devices, organic electroluminescent display devices are so-called self-luminous display devices, in which holes and electrons injected from the first electrode and the second electrode are recombined in the emission layer, and the light-emitting material containing organic compounds in the emission layer emits light to achieve display. Summary of the invention

[0005] Embodiments relate to an organic electroluminescent device, comprising a first electrode, a second electrode on the first electrode, and an emission layer between the first electrode and the second electrode. The emission layer may include a compound, the compound including a first phenyl group substituted with at least one cyano group and a second phenyl group substituted with five substituted or unsubstituted carbazole groups, the second phenyl group being directly bonded to the first phenyl group.

[0006] The at least one cyano group may be substituted on the first phenyl group at the para position or the meta position relative to the second phenyl group.

[0007] The five substituted or unsubstituted carbazole groups may be selected from an unsubstituted carbazole group, a carbazole group substituted with an aryl group having 6 to 18 ring carbon atoms, and a carbazole group substituted with a heteroaryl group having 5 to 18 ring carbon atoms.

[0008] The second phenyl group may be substituted with at least one of a carbazole group substituted with a phenyl group and a carbazole group substituted with a pyridine group.

[0009] The compound can be represented by the following formula 1:

[0010] [Formula 1]

[0011]

[0012] Among them, in formula 1,

[0013] A 1 To A 5At least one of them may be a cyano group, and the others may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms,

[0014] B 1 To B 5 At least one of them can be represented by the following formula 2-1, and the rest can be represented by the following formula 2-2:

[0015] [Formula 2-1]

[0016]

[0017] [Formula 2-2]

[0018]

[0019] Among them, in formula 2-1, X 1 To X 10 Can be N or CR independently 1 ,as well as

[0020] R 1 It may be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms,

[0021] Among them, in formula 2-2,

[0022] R 11 To R 18 Each may independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms.

[0023] Formula 1 can be represented by any one of the following Formulas 1-1 to 1-3:

[0024]

[0025] Among them, in Formula 1-1 to Formula 1-3, A 1 To A 5 and B 1 To B 5 Same as defined in Formula 1.

[0026] Formula 1 can be represented by the following formula 1-4 or formula 1-5:

[0027] [Formula 1-4]

[0028]

[0029] [Formula 1-5]

[0030]

[0031] in,

[0032] In formula 1-4, B 2 and B 4 It can be expressed by formula 2-2,

[0033] In formula 1-5, B 1 , B 3 and B 5 It can be expressed by formula 2-2,

[0034] In formula 1-4 and formula 1-5, A 1 To A 5 may be the same as defined in Formula 1, and

[0035] R 1 To R 10 Each may independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms.

[0036] Formula 2-1 can be represented by the following Formula 2-1A or Formula 2-1B, and Formula 2-2 can be represented by the following Formula 2-2A:

[0037]

[0038] [Formula 2-2A]

[0039]

[0040] The emission layer may emit light by delayed fluorescence.

[0041] The emission layer may be a delayed fluorescence emission layer including a host and a dopant, and the dopant may include the compound.

[0042] The emission layer may emit light having a central wavelength λ of 430 nm to 490 nm. max of blue light.

[0043] The emission layer may include at least one of the following compounds in Compound Group 1:

[0044] [Compound Group 1]

[0045]

[0046]

[0047] Embodiments also relate to 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, the emission layer comprising a compound represented by the following Formula 1:

[0048] [Formula 1]

[0049]

[0050] Among them, in formula 1,

[0051] A 1 To A 5 At least one of them may be a cyano group, and the others may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms,

[0052] B 1 To B 5 At least one of them can be represented by the following formula 2-1, and the rest can be independently represented by the following formula 2-2:

[0053] [Formula 2-1]

[0054]

[0055] [Formula 2-2]

[0056]

[0057] Among them, in formula 2-1, X 1 To X 10 Can be N or CR independently 1 ,as well as

[0058] R 1 It may be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms,

[0059] Among them, in formula 2-2,

[0060] R 11 To R 18Each may independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms.

[0061] The emission layer may emit light having a central wavelength λ of 430 nm to 490 nm. max of blue light.

[0062] The compound may be at least one of the compounds represented in the following compound group 1:

[0063] [Compound Group 1]

[0064]

[0065]

[0066] Embodiments also relate to compounds represented by the following Formula 1:

[0067] [Formula 1]

[0068]

[0069] Among them, in formula 1,

[0070] A 1 To A 5 At least one of them may be a cyano group, and the others may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms,

[0071] B 1 To B 5 At least one of them can be represented by the following formula 2-1, and the others can each be independently represented by the following formula 2-2:

[0072] [Formula 2-1]

[0073]

[0074] [Formula 2-2]

[0075]

[0076] Among them, in formula 2-1, X 1 To X 10 Can be N or CR independently 1 ,as well as

[0077] R1 It may be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms,

[0078] Among them, in formula 2-2,

[0079] R 11 To R 18 Each may independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms.

[0080] Formula 1 can be represented by any one of the following Formulas 1-1 to 1-3:

[0081]

[0082] Among them, in Formula 1-1 to Formula 1-3, A 1 To A 5 and B 1 To B 5 Same as defined in Formula 1.

[0083] Formula 1 can be represented by the following formula 1-4 or formula 1-5:

[0084] [Formula 1-4]

[0085]

[0086] [Formula 1-5]

[0087]

[0088] in,

[0089] In formula 1-4, B 2 and B 4 It can be expressed by formula 2-2,

[0090] In formula 1-5, B 1 , B 3 and B 5 It can be expressed by formula 2-2,

[0091] In formula 1-4 and formula 1-5, A 1 To A 5 Same as defined in Equation 1, and

[0092] R 1 To R 10Each may independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms.

[0093] Formula 2-1 can be represented by the following Formula 2-1A or Formula 2-1B, and Formula 2-2 can be represented by the following Formula 2-2A:

[0094]

[0095] [Formula 2-2A]

[0096]

[0097] Formula 1 may be any one of the following compounds in compound group 1:

[0098] [Compound Group 1]

[0099]

[0100] BRIEF DESCRIPTION OF THE DRAWINGS

[0101] Features will become apparent to those skilled in the art by describing exemplary embodiments in detail with reference to the accompanying drawings, in which:

[0102] Figures 1 to 3 A schematic cross-sectional view of an organic electroluminescent device according to an exemplary embodiment is illustrated. DETAILED DESCRIPTION

[0103] Exemplary embodiments will now be described more fully below with reference to the accompanying drawings; however, they may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that the disclosure will be thorough and complete and will fully convey the exemplary embodiments to those skilled in the art. In the accompanying drawings, the dimensions of layers and regions may be exaggerated for clarity of illustration. The same reference numerals refer to the same elements throughout.

[0104] It will be understood that when an element is referred to as being “on,” “connected” or “coupled” to another element, it can be directly on, connected or coupled to the other element or intervening elements may be present.

[0105] The term "and / or" includes one or more than one combinations that may be limited by the relevant elements.

[0106] It should be understood that although the terms first, second, etc. can be used to describe different elements in this article, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Therefore, without departing from the teachings of the present invention, the first element can be referred to as the second element. Similarly, the second element can be referred to as the first element. As used herein, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise.

[0107] In addition, the terms "lower", "below", "upper", and "above" are used to explain the relationship between elements shown in the drawings. The terms are relative concepts and are explained based on the directions shown in the drawings.

[0108] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. It should also be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and will not be interpreted in an idealized or overly formal sense unless explicitly defined as such herein.

[0109] It should also be understood that the terms “comprises” and / or “comprising”, when used in the present specification, specify the presence of the described features, numbers, steps, operations, elements, parts or a combination thereof, but do not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, parts or a combination thereof.

[0110] Hereinafter, an organic electroluminescent device according to an exemplary embodiment will be explained with reference to the accompanying drawings.

[0111] Figures 1 to 3 is a cross-sectional view schematically showing an organic electroluminescent device according to an exemplary embodiment.

[0112] refer to Figures 1 to 3 In the organic electroluminescent device 10 according to the exemplary embodiment, the first electrode EL1 and the second electrode EL2 are oppositely disposed, and an emission layer EML may be disposed between the first electrode EL1 and the second electrode EL2.

[0113] The organic electroluminescent device 10 according to the present exemplary embodiment may include a plurality of organic layers other than the emission layer EML between the first electrode EL1 and the second electrode EL2. The plurality of organic layers may include a hole transport region HTR and an electron transport region ETR. Therefore, the organic electroluminescent device 10 according to the present exemplary embodiment may include the first electrode EL1, the hole transport region HTR, the emission layer EML, the electron transport region ETR, and the second electrode EL2 laminated one by one.

[0114] The organic electroluminescent device 10 according to the present exemplary embodiment may include a compound according to the exemplary embodiment to be explained below in the emission layer EML between the first electrode EL1 and the second electrode EL2. The organic electroluminescent device 10 according to the present exemplary embodiment may include a compound according to the exemplary embodiment to be explained below in at least one organic layer among a plurality of organic layers other than the emission layer EML between the first electrode EL1 and the second electrode EL2.

[0115] and Figure 1 compared to, Figure 2 1 shows a cross-sectional view of an organic electroluminescent device 10 according to an exemplary embodiment, wherein the hole transport region HTR includes a hole injection layer HIL and a hole transport layer HTL, and the electron transport region ETR includes an electron injection layer EIL and an electron transport layer ETL. Figure 1 When compared, Figure 3 A cross-sectional view of an organic electroluminescent device 10 according to the present exemplary embodiment is shown, wherein 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.

[0116] The first electrode EL1 may have electrical conductivity. The first electrode EL1 may be formed using a metal alloy or a conductive compound. The first electrode EL1 may be an anode. The first electrode EL1 may be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a semi-transmissive reflective electrode or a reflective electrode. If the first electrode EL1 is a transmissive electrode, the first electrode EL1 may be formed using a transparent metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO) and indium tin zinc oxide (ITZO). If the first electrode EL1 is a semi-transmissive reflective electrode or a reflective electrode, the first electrode EL1 may contain Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, a compound thereof or a mixture thereof (e.g., a mixture of Ag and Mg). In addition, the first electrode EL1 may have a structure including a plurality of layers, the plurality of layers including a reflective layer or a semi-transmissive reflective layer formed using the above materials, and a transmissive conductive layer formed using ITO, IZO, ZnO or ITZO. For example, the first electrode EL1 may include a three-layer structure of ITO / Ag / ITO. The thickness of the first electrode EL1 may be about 100 Å. to about For example, about to about

[0117] A hole transport region HTR may be provided on the first electrode EL1. The hole transport region HTR may include at least one of a hole injection layer HIL, a hole transport layer HTL, a hole buffer layer, and an electron blocking layer EBL. The thickness of the hole transport region HTR may be about 1000 Å. to about

[0118] The hole transport region HTR may have a single layer formed using a single material, a single layer formed using a plurality of different materials, or a multi-layered structure including a plurality of layers formed using a plurality of different materials.

[0119] For example, the hole transport region HTR may have a single layer structure of a hole injection layer HIL or a hole transport layer HTL, or may have a single layer structure formed using a hole injection material and a hole transport material. In another embodiment, the hole transport region HTR may have a single layer structure formed using a plurality of different materials, or a structure 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 laminated from the first electrode EL1.

[0120] The hole transport region HTR may be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB), inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0121] The hole injection layer HIL may include, for example, a phthalocyanine compound (e.g., copper phthalocyanine), N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-phenyl-4,4'-diamine (DNTPD), 4,4',4"-[tri(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4',4"-tri(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tri{(2-naphthyl)-N-phenylamino}triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonic acid) ester) (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), polyaniline / camphorsulfonic acid (PANI / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), N,N'-di(1-naphth-1-yl)-N,N'-diphenyl-benzidine (NPB), triphenylamine-containing polyetherketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium [tetrakis(pentafluorophenyl)borate], and dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN).

[0122] The hole transport layer HTL may include, for example, carbazole derivatives (e.g., N-phenylcarbazole and polyvinylcarbazole), fluorine-based derivatives, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD), triphenylamine-based derivatives (e.g., 4,4',4"-tri(N-carbazolyl)triphenylamine (TCTA)), N,N'-di(1-naphth-1-yl)-N,N'-diphenyl-benzidine (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), and the like.

[0123] The thickness of the hole transport region HTR may be about to about For example, about to about The thickness of the hole injection layer HIL may be, for example, about to about And the thickness of the hole transport layer HTL can be about to about For example, the thickness of the electron blocking layer EBL may be about to about 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 ranges, satisfactory hole transport properties may be achieved without a significant increase in driving voltage.

[0124] In addition to the above materials, 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 a quinone derivative, a metal oxide, or a compound containing a cyano group. For example, the p-dopant may include a quinone derivative (e.g., tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinodimethane (F4-TCNQ)), a metal oxide (e.g., tungsten oxide and molybdenum oxide).

[0125] As described above, in addition to the hole injection layer HIL and the hole transport layer HTL, the hole transport region HTR may further include at least one of a hole buffer layer and an electron blocking layer EBL. The hole buffer layer may compensate for the optical resonance distance according to the wavelength of light emitted from the emission layer EML, and may increase the light emission efficiency. The material that may be included in the hole transport region HTR may be used as the material included in the hole buffer layer. The electron blocking layer EBL is a layer that plays a role in preventing electron injection from the electron transport region ETR to the hole transport region HTR.

[0126] An emission layer EML is provided on the hole transport region HTR. The emission layer EML may have, for example, about to about or about to about The emission layer EML may have a single layer formed using a single material, a single layer formed using a plurality of different materials, or a multilayer structure having a plurality of layers formed using a plurality of different materials.

[0127] In the organic electroluminescent device 10 according to the present exemplary embodiment, the emission layer EML may include a compound according to the exemplary embodiment, which may be a compound including a first phenyl group substituted by at least one cyano group and a second phenyl group substituted by five substituted or unsubstituted carbazole groups, the second phenyl group being directly bonded to the first phenyl group.

[0128] In the compound according to this exemplary embodiment, the first phenyl group may include one or two cyano groups as substituents. In the first phenyl group, the remainder not substituted by the cyano group may be unsubstituted or substituted by a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms.

[0129] At least one cyano group substituted in the first phenyl group can be substituted in the para position or meta position relative to the second phenyl group. For example, if the first phenyl group is substituted with one cyano group, the cyano group can be substituted in the para position or meta position relative to the second phenyl group. In addition, for example, if the first phenyl group is substituted with two cyano groups, both cyano groups can be substituted in the meta position relative to the second phenyl group.

[0130] In the compound according to the present exemplary embodiment, the carbazole group substituted on the second phenyl group may be an unsubstituted carbazole group, a carbazole group substituted by an aryl group having 6 to 18 ring carbon atoms, or a carbazole group substituted by a heteroaryl group having 5 to 18 ring carbon atoms. For example, the carbazole group substituted in the second phenyl group may be an unsubstituted carbazole group, a carbazole group substituted by a phenyl group, or a carbazole group substituted by a pyridine group.

[0131] In the compound according to the present exemplary embodiment, the second phenyl group may include at least one of a carbazole group substituted by an aryl group and a carbazole group substituted by a heteroaryl group. For example, the second phenyl group may include at least one carbazole group substituted by a phenyl group as a substituent, or at least one carbazole group substituted by a pyridine group as a substituent. In an exemplary embodiment, the second phenyl group may include a plurality of carbazole groups substituted by phenyl groups as substituents, or a plurality of carbazole groups substituted by pyridine groups as substituents. The second phenyl group may include two or three carbazole groups substituted by phenyl groups as substituents. In another embodiment, the second phenyl group may include two or three carbazole groups substituted by pyridine groups as substituents.

[0132] In addition, the remaining part of the second phenyl group that is not substituted by the carbazole group substituted with an aryl group or the carbazole group substituted with a heteroaryl group may be substituted by an unsubstituted carbazole group. Therefore, in the second phenyl group, all the remaining parts (i.e., excluding the part bonded to the first phenyl group) may be substituted by a substituted or unsubstituted carbazole group.

[0133] In the carbazole group substituted by a phenyl group and substituted on the second phenyl group, the phenyl substituents in the carbazole group may be substituted in the phenyl ring of the carbazole respectively. The phenyl groups substituted in the phenyl rings may be substituted in positions symmetrical to each other. In addition, in the carbazole group substituted by a pyridine group and substituted on the second phenyl group, the pyridine substituents of the carbazole group may be substituted in the phenyl ring of the carbazole respectively. The pyridine groups substituted in the phenyl rings may be substituted in positions symmetrical to each other.

[0134] In the compound according to the present exemplary embodiment, at least one cyano group substituted on the first phenyl group may be an electron acceptor, and the second phenyl group substituted with a substituted or unsubstituted carbazole group may be an electron donor.

[0135] The first phenyl group can be a linker connecting a cyano group substituent and a second phenyl group. The compound according to this exemplary embodiment can include a first phenyl group as a linker between a cyano group with an electron accepting property and a second phenyl group with an electron donating property, and can be used as a material for emitting blue light in a short wavelength region. Therefore, the compound according to this exemplary embodiment can be used as a luminescent material emitting dark blue light.

[0136] In this description, the term "substituted or unsubstituted" corresponds to being substituted or unsubstituted by 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 oxy group, a sulfenyl group, a sulfinyl group, a sulfonyl group, a carbonyl group, a boron 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 may be substituted or unsubstituted. For example, a biphenyl group may be interpreted as an aryl group or a phenyl group substituted by a phenyl group.

[0137] In the present description, the halogen atom may be a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0138] In the present description, the alkyl group may be a linear, branched or cyclic type. The carbon number of the alkyl group may be 1 to 50, 1 to 30, 1 to 20, 1 to 10 or 1 to 6. Examples of the alkyl group may include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, tert-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2-butyl Decyl, 2-hexyldecyl, 2-octyldecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, 2-ethyleicosyl, 2-butyleicosyl, 2-hexyleicosyl, 2-octyleicosyl, n-heneicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, n-triacontyl, and the like.

[0139] In the present description, an aryl group means a functional group or a substituent derived from an aromatic hydrocarbon ring. The aryl group may be a monocyclic aryl group or a polycyclic aryl group. The number of carbon atoms used to form the ring in the aryl group may be 6 to 30, 6 to 20, or 6 to 15. Examples of aryl groups may include phenyl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl, biphenyl, terphenyl, quaterphenyl, pentaphenyl, hexaphenyl, triphenylenyl, pyrenyl, benzofluoranthenyl, Ji et al.

[0140] In the present description, the heteroaryl group may be a heteroaryl group containing at least one of O, N, P, Si and S as a heteroatom. If the heteroaryl group contains two or more heteroatoms, the two or more heteroatoms may be the same or different. The heteroaryl group may be a monocyclic heteroaryl group or a polycyclic heteroaryl group. The carbon number of the heteroaryl group for forming a ring may be 2 to 30, 2 to 20 or 2 to 10, and the heteroatom number of the heteroaryl group for forming a ring may be 1 to 10, 1 to 5 or 1 to 3, such as 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10. Examples of heteroaryl groups may include thienyl, furanyl, pyrrolyl, imidazolyl, triazolyl, pyridyl, bipyridyl, pyrimidyl, triazinyl, acridinyl, pyridazinyl, pyrazinyl, quinolyl, quinazolinyl, quinoxalinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolyl, indolyl, carbazolyl, N-arylcarbazolyl, N-heteroarylcarbazolyl, N-alkylcarbazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothienyl, dibenzothienyl, thienothiphenyl, benzofuranyl, phenanthrolinyl, thiazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, phenothiazinyl, dibenzosilolyl, dibenzofuranyl, and the like.

[0141] In this description, "-*" means a connection position.

[0142] The emission layer EML of the organic electroluminescent device 10 according to the present exemplary embodiment may include a compound represented by Formula 1 below.

[0143] [Formula 1]

[0144]

[0145] In formula 1, A 1 To A 5 At least one of them may be a cyano group, and the others may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms. 1 To A 5 may each independently be a cyano group, a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms, provided that A 1 To A 5 At least one of them is a cyano group.

[0146] In addition, B in Formula 1 1 To B5 At least one of may be represented by the following Formula 2-1, and the rest may be represented by the following Formula 2-2.

[0147] [Formula 2-1]

[0148]

[0149] [Formula 2-2]

[0150]

[0151] In Formula 1, A 1 To A 5 The phenyl group (ie, ) corresponds to the first phenyl group and is substituted with B 1 To B 5 The phenyl group (ie, ) corresponds to the second phenyl group.

[0152] In formula 2-1, X 1 To X 10 Can be N or CR independently 1 , and R 1 It may be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms. 1 To X 10 Both can be CR 1 In this case, all R 1 The radical may be a hydrogen atom.

[0153] In addition, in formula 2-1, X 1 To X 5 Any one of 6 To X 10 Any one of can be N. Selected from X 1 To X 5 Any one of and selected from X 6 To X 10 Any one of them can be N, and the rest can be CR 1 In this case, all R 1 The radical may be a hydrogen atom.

[0154] In formula 2-2, R 11 To R 18Each of them may be independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms. For example, in the carbazole group represented by Formula 2-1 or Formula 2-2, R 1 and R 11 To R 18 Therefore, Formula 2-1 can be represented by the following Formula 2-1A or Formula 2-1B, and Formula 2-2 can be represented by the following Formula 2-2A.

[0155]

[0156]

[0157] [Formula 2-2A]

[0158]

[0159] In an exemplary embodiment, in addition to hydrogen atoms, R 1 and R 11 To R 18 may each independently be a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms, and may be selected from a plurality of R 1 Two or more than two of the groups, or selected from R 11 To R 18 At least two of may be the same or different.

[0160] Formula 2-1 can be represented by any one of the following Formulas 3-1 to 3-3.

[0161]

[0162] [Formula 3-3]

[0163]

[0164] In Formula 3-1 to Formula 3-3, Ra to Rj may each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 30 ring carbon atoms, and two or more selected from Ra to Rj may be the same or different. For example, Ra to Rj may be a hydrogen atom.

[0165] In Formula 1, selected from A 1 To A 5One or both of may be a cyano group. For example, Formula 1 may be represented by any one of the following Formulas 1-1 to 1-3.

[0166]

[0167] Formula 1-1 and Formula 1-2 correspond to the case where one cyano group is substituted in the first phenyl group, and Formula 1-3 corresponds to the case where two cyano groups are substituted in the first phenyl group.

[0168] Formula 1-1 represents a compound in which the substituted cyano group is substituted at the para position relative to the second phenyl group, and Formula 1-2 represents a compound in which the substituted cyano group is substituted at the meta position relative to the second phenyl group. In addition, Formula 1-3 represents a compound comprising two cyano groups as substituents, wherein the two cyano groups are substituted at the meta position relative to the second phenyl group.

[0169] In Formula 1-1 to Formula 1-3, the same explanation concerning Formula 1 can be applied to A 1 To A 5 and B 1 To B 5 .

[0170] In Formula 1, selected from B 1 To B 5 Two or three of them may be represented by Formula 2-1, and the rest may be represented by Formula 2-2. For example, Formula 1 may be represented by the following Formula 1-4 or Formula 1-5.

[0171] [Formula 1-4]

[0172]

[0173] [Formula 1-5]

[0174]

[0175] In formula 1-4, B 2 and B 4 It can be expressed by formula 2-2, and in formula 1-5, B 1 , B 3 and B 5 It can be expressed by formula 2-2. 1 To R 10 The alkyl radicals may each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms.

[0176] Formula 1-4 represents a case where the second phenyl group includes three substituted carbazole groups as substituents, and Formula 1-5 represents a case where the second phenyl group includes two substituted carbazole groups as substituents.

[0177] In Formulas 1-4 and 1-5, the same explanations concerning Formula 1 can be applied to A 1 To A 5 .

[0178] The compound according to the present exemplary embodiment may be any one of the compounds represented in the following Compound Group 1.

[0179] [Compound Group 1]

[0180]

[0181]

[0182]

[0183] In an exemplary embodiment, the organic electroluminescent device 10 may include at least one compound among the compounds represented in the compound group 1 in the emission layer EML.

[0184] According to an exemplary embodiment, the compound represented by Formula 1 may be a material for emitting light by thermally activated delayed fluorescence. In an exemplary embodiment, the compound represented by Formula 1 may have an energy difference ΔE between the lowest triplet excitation energy level (T1 energy level) and the lowest singlet excitation energy level (S1 energy level) of about 0.25 eV or less. ST Thermally activated delayed fluorescence dopants.

[0185] According to an exemplary embodiment, the compound represented by Formula 1 may have a light emitting center wavelength (λ max ) of the light-emitting material. For example, the compound according to the present exemplary embodiment represented by Formula 1 may have a light-emitting center wavelength λ in a wavelength region of about 430 nm to about 490 nm. max According to an exemplary embodiment, the compound represented by Formula 1 may be a deep blue thermally activated delayed fluorescence dopant.

[0186] In the organic electroluminescent device 10 according to the present exemplary embodiment, the emission layer EML may emit light by delayed fluorescence. For example, the emission layer EML may emit light by thermally activated delayed fluorescence (TADF).

[0187] The organic electroluminescent device 10 according to the exemplary embodiment may include a plurality of emission layers. The plurality of emission layers may be laminated one by one. For example, the organic electroluminescent device 10 including a plurality of emission layers may emit white light. The organic electroluminescent device including a plurality of emission layers may be an organic electroluminescent device having a tandem structure. If the organic electroluminescent device 10 includes a plurality of emission layers, at least one emission layer EML may include the compound according to the exemplary embodiment.

[0188] In the exemplary embodiment, the emission layer EML includes a host and a dopant, and may include the compound according to the exemplary embodiment as a dopant. For example, in the organic electroluminescent device 10 according to the exemplary embodiment, the emission layer EML may include a host for emitting light by delayed fluorescence and a dopant for emitting light by delayed fluorescence, and may include the compound according to the exemplary embodiment as a dopant for emitting delayed fluorescence. The emission layer EML may include at least one of the compounds represented in compound group 1 as a thermally activated delayed fluorescence dopant.

[0189] In an exemplary embodiment, the emission layer EML may be a delayed fluorescent emission layer, and the emission layer EML may include a suitable host material and the compound according to the exemplary embodiment. For example, in an embodiment, the compound may be used as a TADF dopant.

[0190] In an exemplary embodiment, the emission layer EML may include a suitable host material. For example, in an exemplary embodiment, the emission layer EML may include tris(8-hydroxyquinolinolato)aluminum (Alq 3 )、4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), poly(N-vinylcarbazole) (PVK), 9,10-di(naphthalene-2-yl)anthracene (ADN), 4,4',4"-tri(carbazol-9-yl)-triphenylamine (TCTA), 1,3,5-tri(N-phenylbenzimidazol-2-yl)benzene (TPBi), 3-tert-butyl-9,10-di(naphthalene-2-yl)anthracene (TBADN ), distyrylarylene (DSA), 4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl (CDBP), 2-methyl-9,10-bis(naphthalene-2-yl)anthracene (MADN), bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO 3 ), octaphenylcyclotetrasiloxane (DPSiO 4), 2,8-bis(diphenylphosphoryl)dibenzofuran (PPF), 3,3'-bis(N-carbazolyl)-1,1'-biphenyl (mCBP), 1,3-bis(N-carbazolyl)benzene (mCP), etc. Suitable host materials for emitting delayed fluorescence other than the annotated host materials may be included.

[0191] In the organic electroluminescent device 10 according to the exemplary embodiment, the emission layer EML may further include a suitable dopant material. In the exemplary embodiment, the emission layer EML may include 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), and N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalene-2-yl)vinyl)phenyl)-N-phenylaniline (N-BDAVBi)), perylene and its derivatives (e.g., 2,5,8,11-tetra-tert-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1-dipyrene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene), and the like as a dopant.

[0192] In the organic electroluminescent device 10 according to the exemplary embodiment, as Figures 1 to 3 As shown in , an electron transport region ETR may be provided on the emission layer EML. The electron transport region ETR may include at least one of a hole blocking layer HBL, an electron transport layer ETL, and an electron injection layer EIL.

[0193] The electron transport region ETR may 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.

[0194] 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 addition, the electron transport region ETR may have a single-layer structure containing a plurality of different materials, or a structure of an electron transport layer ETL / electron injection layer EIL laminated from an emission layer EML, or a structure of a hole blocking layer HBL / electron transport layer ETL / electron injection layer EIL. The thickness of the electron transport region ETR may be, for example, about to about

[0195] The electron transport region ETR may be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB), inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0196] If the electron transport region ETR includes an electron transport layer ETL, the electron transport region ETR may include an anthracene-based compound. The electron transport region may include, for example, tris(8-hydroxyquinolinolato)aluminum (Alq 3 ), 1,3,5-tris[(3-pyridyl)-phenyl-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 3-(4-biphenyl)- 4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-ato)aluminum (BAlq), bis(benzoquinolin-10-ato)beryllium (Bebq2), 9,10-di(naphthalene-2-yl)anthracene (ADN), or a mixture thereof. The thickness of the electron transport layer ETL may be about 1000 nm. to about and can be, for example, about to about If the thickness of the electron transport layer ETL satisfies the above range, satisfactory electron transport properties may be obtained without a significant increase in driving voltage.

[0197] If the electron transport region ETR includes the electron injection layer EIL, the electron transport region ETR may include, for example, LiF, 8-hydroxyquinolinolato-lithium (LiQ), Li 2 O, BaO, NaCl, CsF, lanthanide metals (e.g., Yb) or metal halides (e.g., RbCl, RbI and KI). The electron injection layer EIL can also be formed using a mixture material of an electron injection material and an insulating organic metal salt. The organic metal salt can be a material having an energy band gap of about 4 eV or greater than 4 eV. In particular, the organic metal salt can include, for example, metal acetate, metal benzoate, metal acetoacetate, metal acetylacetonate or metal stearate. The thickness of the electron injection layer EIL can be about 1000 nm. to about For example, about to about If the thickness of the electron injection layer EIL satisfies the above range, satisfactory electron injection properties can be obtained without a significant increase in driving voltage.

[0198] The electron transport region ETR may include the 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).

[0199] A second electrode EL2 may be provided on the electron transport region ETR. The second electrode EL2 may be a common electrode or a cathode. The second electrode EL2 may be a transmissive electrode, a semi-transmissive reflective electrode, or a reflective electrode. If the second electrode EL2 is a transmissive electrode, the second electrode EL2 may include a transparent metal oxide, such as ITO, IZO, ZnO, ITZO, etc.

[0200] If the second electrode EL2 is a semi-transmissive reflective electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, a compound thereof, or a mixture thereof (e.g., a mixture of Ag and Mg). The second electrode EL2 may have a multilayer structure including a reflective layer or a semi-transmissive reflective layer formed using the above materials and a transparent conductive layer formed using ITO, IZO, ZnO, ITZO, etc.

[0201] The second electrode EL2 may be connected to the auxiliary electrode. If the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0202] A cover layer may be further disposed on the second electrode EL2 of the organic electroluminescent device 10. The cover layer may include, for example, α-NPD, NPB, TPD, m-MTDATA, Alq 3 , CuPc, N4,N4,N4',N4'-tetrakis(biphenyl-4-yl)biphenyl-4,4'-diamine (TPD15), 4,4',4"-tris(carbazol-9-yl)triphenylamine (TCTA), etc.

[0203] The organic electroluminescent device 10 according to the exemplary embodiment includes the compound according to the exemplary embodiment in the emission layer EML between the first electrode EL1 and the second electrode EL2, thereby showing excellent life characteristics and emitting blue light in the short wavelength region. In addition, the compound according to the exemplary embodiment may be a thermally activated delayed fluorescence dopant, and the emission layer EML may include the compound according to the exemplary embodiment to emit light by thermally activated delayed fluorescence. Therefore, excellent emission efficiency properties can be achieved while emitting short-wavelength blue light.

[0204] The compound according to the present exemplary embodiment 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 the exemplary embodiment may include the compound in at least one organic layer between the first electrode EL1 and the second electrode EL2, or in a cover layer on the second electrode EL2.

[0205] The following examples and comparative examples are provided to highlight the characteristics of one or more than one embodiment, but it should be understood that the examples and comparative examples are not interpreted as limiting the scope of the embodiments, and the comparative examples are not interpreted as being outside the scope of the embodiments. In addition, it should be understood that the embodiments are not limited to the specific details described in the examples and comparative examples.

[0206] [Example]

[0207] 1. Synthesis of compounds according to exemplary embodiments

[0208] An exemplary synthesis method of the polycyclic compound according to the exemplary embodiment will now be explained with reference to the synthesis methods of Compound 1 to Compound 4.

[0209] (Synthesis Method of Compound 1)

[0210] <Synthesis of Intermediate A-1>

[0211]

[0212] To a three-necked flask were added 10 g (55 mmol) of 4-bromobenzonitrile, 9.2 g (55 mmol) of pentafluorobenzene, 1.0 g (5.5 mmol) of CuI, 1.0 g (5.5 mmol) of phenanthroline and 23 g (110 mmol) of K. 3 PO 4 , and argon (Ar) flushing is performed. Then, 16 ml of DMF and 16 ml of xylene are added thereto, and then heated and stirred at about 130 ° C for about 24 hours. The reaction solution thus obtained is extracted with ethyl acetate, washed with brine, dried over magnesium sulfate, filtered using a silica gel pad and separated by silica gel column chromatography (mixed solvent of hexane / ethyl acetate) to obtain 9.6 g (yield 65%) of a white solid. The molecular weight of the isolated product thus obtained is determined to be 269 by FAB-MS measurement, and the generation of the intermediate A-1 of the target material is confirmed.

[0213] <Synthesis of Intermediate A-2>

[0214]

[0215] 1.0 g (3.7 mmol) of intermediate A-1, 4.2 g (13 mmol) of 3,6-diphenylcarbazole and 0.22 g (9.3 mmol) of NaH were added to a three-necked flask and purged with argon. 60 ml of DMF was added thereto and then stirred at about 0° C. for about 30 minutes. Then, the temperature of the reaction system was raised to room temperature and the reaction system was stirred for about 6 hours. Water was added to the reaction system and the organic layer was extracted with dichloromethane and filtered through MgSO 4 Dry. Then, remove the solvent by distillation. The crude product thus obtained is separated by silica gel column chromatography (mixed solvent of hexane / toluene) and using a recrystallization solvent (mixed solvent of ethanol / toluene) to obtain 0.79g (yield 30%) of a light yellow solid. The molecular weight of the isolated product thus obtained was found to be 1167 by FAB-MS measurement, and it was confirmed to be the generation of the intermediate A-2 of the target material.

[0216] <Synthesis of Compound 1>

[0217]

[0218] 0.67 g (0.97 mmol) of intermediate A-2, 0.30 g (1.9 mmol) of carbazole and 0.57 g (2.3 mmol) of NaH were added to a three-necked flask and purged with argon. 60 ml of DMF was added thereto and then stirred at about 0° C. for about 30 minutes. Then, the temperature of the reaction system was raised to room temperature and the reaction system was stirred for about 6 hours. Water was added to the reaction system and the organic layer was extracted with dichloromethane and filtered through MgSO 4 The crude product thus obtained was separated by silica gel column chromatography (mixed solvent of hexane / toluene) and using a recrystallization solvent (mixed solvent of ethanol / toluene) to obtain 0.74 g (yield 60%) of a light yellow solid. The molecular weight of the isolated product thus obtained was found to be 1448 by FAB-MS measurement, and the production of compound 1 was confirmed.

[0219] (Synthesis Example of Compound 2)

[0220] <Synthesis of Intermediate A-3>

[0221]

[0222] Except that carbazole is used instead of 3,6-diphenylcarbazole, intermediate A-3 is synthesized by carrying out the same procedure as in the synthesis method of intermediate A-2. 0.42 g (yield 16%) of a light yellow solid is obtained. The molecular weight of the isolated product thus obtained is found to be 711 by FAB-MS measurement, and the generation of intermediate A-3 as the target material is confirmed.

[0223] <Synthesis of Compound 2>

[0224]

[0225] Compound 2 was synthesized by performing the same procedure as in the synthesis method of Compound 1 except that 3,6-diphenylcarbazole was used instead of carbazole. 0.43 g (yield 70%) of a pale yellow solid was obtained. The molecular weight of the isolated product thus obtained was found to be 1310 by FAB-MS measurement, and the production of Compound 2 was confirmed.

[0226] (Synthesis Example of Compound 3)

[0227] <Synthesis of Intermediate B-1>

[0228]

[0229] Except using 5-bromoisophthalonitrile instead of 4-bromobenzonitrile, intermediate B-1 is synthesized by carrying out the same procedure as in the synthesis method of intermediate A-1. 11 g (yield 80%) of white solid is obtained. The molecular weight of the isolated product thus obtained is found to be 294 by FAB-MS measurement, and the generation of intermediate B-1 is confirmed.

[0230] <Synthesis of Intermediate B-2>

[0231]

[0232] Except that intermediate B-1 is used to replace intermediate A-1 and carbazole is used to replace 3,6-diphenylcarbazole, intermediate B-2 is synthesized by performing the same procedure as in the synthesis method of intermediate A-2. 0.53 g (yield 21%) of a light yellow solid is obtained. The molecular weight of the isolated product thus obtained is found to be 736 by FAB-MS measurement, and the generation of intermediate B-2 as the target material is confirmed.

[0233] <Synthesis of Compound 3>

[0234]

[0235] Except that intermediate B-2 is used instead of intermediate A-2 and 3,6-diphenylcarbazole is used instead of carbazole, compound 3 is synthesized by performing the same procedure as in the synthesis method of compound 1. 0.34 g (yield 63%) of a light yellow solid is obtained. The molecular weight of the isolated product thus obtained is found to be 1335 by FAB-MS measurement, and the production of compound 3 is confirmed.

[0236] (Synthesis of Compound 4)

[0237] <Synthesis of Intermediate C-1>

[0238]

[0239] Except that 3-bromobenzonitrile is used instead of 4-bromobenzonitrile, intermediate C-1 is synthesized by carrying out the same procedure as in the synthesis method of intermediate A-1. 11 g (yield 76%) of a white solid is obtained. The molecular weight of the isolated product thus obtained is found to be 269 by FAB-MS measurement, and the generation of intermediate C-1 as the target material is confirmed.

[0240] <Synthesis of Intermediate C-2>

[0241]

[0242] Except that intermediate C-1 is used to replace intermediate A-1 and carbazole is used to replace 3,6-diphenylcarbazole, intermediate C-2 is synthesized by performing the same procedure as in the synthesis method of intermediate A-2. 0.37 g (yield 14%) of a light yellow solid is obtained. The molecular weight of the isolated product thus obtained is found to be 711 by FAB-MS measurement, and the generation of intermediate C-2 as the target material is confirmed.

[0243] <Synthesis of Compound 4>

[0244]

[0245] Except that intermediate C-2 is used instead of intermediate A-2 and 3,6-diphenylcarbazole is used instead of carbazole, compound 4 is synthesized by performing the same procedure as in the synthesis method of compound 1. 0.41 g (yield 76%) of a light yellow solid is obtained. The molecular weight of the isolated product thus obtained is found to be 1310 by FAB-MS measurement, and the production of compound 4 is confirmed.

[0246] 2. Evaluation of the energy levels of compounds

[0247] In the following Table 1, the lowest singlet excitation energy level (S1 level), the lowest triplet excitation energy level (T1 level) and E1 of the following compounds 1 to 4 (which are example compounds) and comparative compound C1 are shown. ST value.

[0248]

[0249] In Table 1, energy level values ​​were calculated by a non-empirical molecular orbital method. Specifically, the calculation was performed by B3LYP / 6-31G(d) using Gaussian 09 of Gaussian Co. STIt represents the difference between the lowest singlet excited energy level (S1 level) and the lowest triplet excited energy level (T1 level).

[0250] [Table 1]

[0251] Compound S1 energy level (eV) T1 energy level (eV) <![CDATA[E ST (eV)]]> Compound 1 2.87 2.73 0.14 Compound 2 2.92 2.75 0.17 Compound 3 3.01 2.79 0.22 Compound 4 3.86 2.71 0.15 Comparative Compound C1 2.60 2.46 0.14

[0252] Compounds 1 to 4, which are example compounds, have an E of about 0.25 eV or less. ST Based on the results, it is believed that compounds 1 to 4 can be used as thermally activated delayed fluorescence dopant materials. In addition, comparative compound C1 also shows a low E ST value and is considered to be useful as a thermally activated delayed fluorescence dopant material.

[0253] 3. Evaluation of Fluorescence Emission Properties of Compounds

[0254] Fluorescence emission properties were evaluated using a V-670 spectrometer of JASCO Corporation. An organic layer was formed on quartz glass by co-depositing PPF represented below as a host material and each of Compounds 1 to 4 and Comparative Compound C1 as a dopant material.

[0255]

[0256] The ratio of the co-deposited host and dopant was 80:20. Regarding the organic layer thus manufactured, the fluorescence emission spectrum was measured. The fluorescence quantum yield was measured using an ILF-835 integrating sphere system of JASCO Corporation.

[0257] The following Table 2 shows the fluorescence emission properties of the Examples and Comparative Examples, and in the evaluation of the fluorescence emission properties, λ max represents the emission center wavelength, which indicates the maximum emission intensity in the luminescence peak.

[0258] [Table 2]

[0259] Grouping Dopant materials <![CDATA[λ max (nm)]]> Fluorescence quantum yield (%) Example 1 Compound 1 450 85 Example 2 Compound 2 443 78 Example 3 Compound 3 430 80 Example 4 Compound 4 452 75 Comparative Example 1 Comparative Compound C1 495 80

[0260] Referring to the results of Table 2, Examples 1 to 4 showed fluorescence quantum yields of a similar degree to that of Comparative Example 1. When compared with the emission center wavelength of Comparative Example 1, it was found that the emission center wavelengths (λ max ) corresponds to the short wavelength region. Therefore, according to the results of Table 2, when compared with the comparative compound C1, it was found that the example compound emitted deep blue light, which is blue light in the short wavelength region.

[0261] 4. Fabrication and evaluation of organic electroluminescent devices

[0262] (Manufacturing of organic electroluminescent device)

[0263] The organic electroluminescent device of the exemplary embodiment including the compound of the exemplary embodiment in the emission layer was manufactured by the method described below. The organic electroluminescent devices of Examples 1 to 4 were manufactured using the compounds of Compounds 1 to 4 as dopant materials for the emission layer. The organic electroluminescent device of the comparative example was manufactured using Comparative Compound C1 as a dopant material in the emission layer.

[0264] On a glass substrate, there will be approximately The ITO of thickness of 10000 was patterned and washed with ultrapure water, washed with ultrasonic wave, exposed to UV for about 30 minutes and treated with ozone. Then, 1,4,5,8,9,11-hexaazatriphenylene hexacarbonitrile (HAT-CN) was deposited to about To form a hole injection layer, N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB) was deposited to a thickness of about Then, 1,3-bis(N-carbazolyl)benzene (mCBP) was deposited to a thickness of about to form an electron blocking layer.

[0265] On the electron blocking layer, bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO) and each of the example compounds or comparative compounds were co-deposited at a ratio of 80:20 to form an emission layer to about Therefore, the emission layer was formed by co-deposition of Compound 1, Compound 2, Compound 3 or Compound 4 and DPEPO in Examples 1 to 4, or co-deposition of Comparative Compound C1 and DPEPO in Comparative Example 1.

[0266] On the emission layer, a hole blocking layer was formed using DPEPO to about Then, an electron transport layer was formed using 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi) to a thickness of about Then, an electron injection layer is formed using 8-hydroxyquinolinolato-lithium (Liq) to a thickness of about Then, a second electrode is formed using aluminum (Al) to a thickness of about Thickness.

[0267] In an embodiment, a hole injection layer, a hole transport layer, an electron blocking layer, an emission layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a second electrode are formed by using a vacuum deposition apparatus.

[0268] (Evaluation of properties of organic electroluminescent devices)

[0269] In Table 3, the evaluation results of the organic electroluminescent devices of Examples 1 to 4 and Comparative Example 1 are shown. In Table 3, the λ max (which is the emission center wavelength), emission efficiency and lifetime. In the evaluation results of the properties of the embodiments and comparative examples, as shown in Table 3, the voltage and current density were measured using a source meter (2400 series, Keithley Instrument Co.), and the brightness and external quantum efficiency were measured using an external quantum efficiency measurement device C9920-12 from Hamamatsu Photonics Co. The emission efficiency is expressed relative to 10 mA / cm 2 The current efficiency value of the current density and the lifetime are expressed at 1.0 mA / cm 2 The lower half-life.

[0270] The emission efficiency and lifetime were compared and shown as relative values ​​in Table 3. The emission efficiency and lifetime in Examples are relative to the emission efficiency and lifetime in Comparative Example 1 (they were set to 1).

[0271] [Table 3]

[0272] Grouping Dopant materials <![CDATA[λ max (nm)]]> Transmission efficiency life Example 1 Compound 1 453 1.03 0.95 Example 2 Compound 2 442 0.98 1.01 Example 3 Compound 3 435 0.95 0.91 Example 4 Compound 4 454 0.96 0.95 Comparative Example 1 Comparative Compound C1 497 1 1

[0273] Referring to the results in Table 3, it is found that the organic electroluminescent devices of Examples 1 to 4 show emission efficiency and life characteristics to a similar degree as those of the organic electroluminescent device of Comparative Example 1. However, when compared with the organic electroluminescent device of Comparative Example 1, the organic electroluminescent devices of Examples 1 to 4 show an emission maximum peak λ in the short wavelength region. max From the perspective of the present invention, it was found that when compared with Comparative Example 1, Examples 1 to 4 emitted deep blue light, which is blue light with a short wavelength.

[0274] With reference to the evaluation results of the examples of the compound and the organic electroluminescent device, it is found that the compound according to the exemplary embodiment can be used as a material for emitting deep blue light and can show excellent life characteristics. In addition, in the organic electroluminescent device according to the exemplary embodiment (which includes the compound according to the exemplary embodiment in the emission layer), excellent emission efficiency properties and life characteristics are shown while emitting deep blue light.

[0275] By way of summary and review, in the application of organic electroluminescent devices to display devices, a reduction in driving voltage of the organic electroluminescent devices and an increase in emission efficiency and lifespan are desired.

[0276] In order to provide an organic electroluminescent device with high efficiency, technologies regarding phosphorescence emission (which uses the energy of the triplet state) or delayed fluorescence emission (which uses the generation phenomenon of singlet excitons through the collision of triplet excitons (triplet-triplet annihilation, TTA)) are considered, and suitable materials for thermally activated delayed fluorescence (TADF) using the delayed fluorescence phenomenon are of interest.

[0277] As described above, the embodiment relates to a compound used as a light-emitting material and an organic electroluminescent device including the compound.

[0278] Without being bound by theory, it is believed that in the compound according to the exemplary embodiment, the compound contains a phenyl group as a linker between a cyano group as an electron acceptor and a phenyl group substituted with a carbazole group as an electron donor, the electron accepting property of the cyano group may be weakened, and therefore, it can be used as a light-emitting material that exhibits excellent life characteristics and emits deep blue light. In addition, the organic electroluminescent device according to the exemplary embodiment (including the compound according to the exemplary embodiment in the emission layer) can show excellent emission efficiency and life characteristics while emitting deep blue light.

[0279] The organic electroluminescent device according to the exemplary embodiment may emit deep blue light and show excellent lifespan characteristics.

[0280] The compound according to the exemplary embodiment may be included in an emission layer of an organic electroluminescent device and may emit deep blue light.

[0281] Exemplary embodiments have been disclosed herein, and although specific terms are employed, they are used and interpreted in a general and descriptive sense only, and not for limiting purposes. In some cases, as would be apparent to one of ordinary skill in the art prior to filing this application, features, characteristics, and / or elements described with respect to a particular embodiment may be used alone or in combination with features, characteristics, and / or elements described with respect to other embodiments, unless otherwise expressly indicated. Therefore, it should be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention as set forth in the claims.

Claims

1. A compound represented by the following formula 1: [Formula 1] in, In formula 1, One or two of A1 to A5 are cyano groups, and the others are each independently a hydrogen atom, a deuterium atom, a halogen atom, or a substituted or unsubstituted alkyl group of 1 to 10 carbon atoms, Two or three of B1 to B5 are represented by the following Formula 2-1, and the rest are represented by the following Formula 2-2: [Formula 2-1] [Formula 2-2] In formula 2-1, X1 to X 10 Each independently represents N or CR1, wherein X1 to X 10 are CR1, or any one selected from X1 to X5 and any one selected from X6 to X 10 Any one of is N, and the rest are CR1, and R1 is a hydrogen atom or a deuterium atom, Among them, in formula 2-2, R 11 To R 18 are each independently a hydrogen atom or a deuterium atom, wherein the substituent for said substitution is selected from the group consisting of a deuterium atom and a halogen atom.

2. The compound according to claim 1, wherein Formula 1 is represented by any one of the following Formulas 1-1 to 1-3: in, In Formulae 1-1 to 1-3, A1 to A5 and B1 to B5 are the same as defined in Formula 1.

3. The compound according to claim 1, wherein Formula 1 is represented by the following Formula 1-4 or Formula 1-5: [Formula 1-4] [Formula 1-5] in, In formula 1-4, B2 and B4 are represented by formula 2-2, In formula 1-5, B1, B3 and B5 are represented by formula 2-2, In Formulas 1-4 and 1-5, A1 to A5 are the same as defined in Formula 1, and R1 to R 10 are each independently a hydrogen atom or a deuterium atom.

4. The compound according to claim 1, wherein Formula 2-1 is represented by the following Formula 2-1A or Formula 2-1B, and Formula 2-2 is represented by the following Formula 2-2A: [Formula 2-2A] 5. The compound according to claim 1, wherein Formula 1 is any one of the compounds in the following compound group 1: [Compound Group 1] 6. An organic electroluminescent device comprising: a first electrode; a second electrode on the first electrode; as well as an emitting layer between the first electrode and the second electrode, The emission layer comprises the compound according to any one of claims 1 to 5. 7 . The organic electroluminescent device as claimed in claim 6 , wherein the at least one cyano group is substituted at the para position or the meta position. The organic electroluminescent device as claimed in claim 6 , wherein the emission layer emits light by delayed fluorescence. 9 . The organic electroluminescent device as claimed in claim 6 , wherein the emission layer is a delayed fluorescent emission layer including a host and a dopant, and the dopant includes the compound.

10. The organic electroluminescent device according to claim 6, wherein the emission layer emits light having a central wavelength λ of 430 nm to 490 nm. max of blue light.

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