Organic electroluminescent device and fused polycyclic compound

Abstract

An organic electroluminescent device and a fused polycyclic compound are provided. An organic electroluminescent device of the present embodiment includes a first electrode and a second electrode disposed opposite to each other, and a plurality of organic layers disposed between the first electrode and the second electrode, in which at least one of the plurality of organic layers includes a fused polycyclic compound represented by Formula 1 below, thereby exhibiting improved emission efficiency: Formula 1 # imgabs0 #

Description

[0001] This application is a divisional application of a patent application with an application date of May 20, 2020 and application number 202010428804.7 and an invention name of “Organic electroluminescent devices and fused polycyclic compounds”. Technical Field

[0002] One or more embodiments of the present disclosure relate to an organic electroluminescent device and a fused polycyclic compound used in an organic electroluminescent device, and more specifically, to a fused polycyclic compound used as a light-emitting material and an organic electroluminescent device including the fused polycyclic compound. Background Art

[0003] Recently, the development of organic electroluminescent display devices as image display devices is being actively carried out. Unlike liquid crystal display devices, organic electroluminescent display devices are 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 including organic compounds in the emission layer emits light to realize image display.

[0004] When organic electroluminescent devices are applied to display devices, there is a need (or expectation) for lowering the driving voltage of the organic electroluminescent devices and improving the emission efficiency and lifetime, and there is a continuous need (or expectation) for the development of materials for organic electroluminescent devices that can stably achieve these characteristics.

[0005] Recently, in order to realize organic electroluminescent devices with high efficiency, technologies regarding phosphorescence emission (which utilizes triplet energy) or delayed fluorescence emission (which utilizes a phenomenon in which singlet excitons are generated by collision of triplet excitons (triplet-triplet annihilation, TTA)) are being developed, and development of thermally activated delayed fluorescence (TADF) materials utilizing the delayed fluorescence phenomenon is underway. Summary of the invention

[0006] One or more aspects of embodiments of the present disclosure are directed to an organic electroluminescent device having improved emission efficiency.

[0007] One or more aspects of the embodiments of the present disclosure also relate to a fused polycyclic compound capable of improving the emission efficiency of an organic electroluminescent device.

[0008] An embodiment of the inventive concept provides an organic electroluminescent device including a first electrode, a second electrode facing the first electrode, and a plurality of organic layers between the first electrode and the second electrode. At least one organic layer among the plurality of organic layers includes a fused polycyclic compound represented by the following Formula 1:

[0009] Formula 1

[0010]

[0011] In Formula 1, M is B, Al, Ga or In; X 1 and X 2 can be independently NR 1 ,O,S,P(=O)R 2 or P(=S)R 3 ; R 1 To R 3 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 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 60 carbon atoms for forming a ring, and R 1 To R 3 Any one of the groups may (optionally) combine with an adjacent group to form a ring; Cy 1 To Cy 3 may be independently a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring, and Cy 1 To Cy 3 Any one of may (optionally) combine with an adjacent group to form a ring, and Cy 1 To Cy 3 At least one of them is substituted with a substituent represented by the following formula 2:

[0012] Formula 2

[0013]

[0014] In formula 2, R 4 and R 5 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms for forming a ring, and R 4 and R 5 Any one of the groups may (optionally) combine with an adjacent group to form a ring; 1 and n 2 are independently an integer from 0 to 4; R 4 and R 5 At least one of them is a substituted or unsubstituted amine group or a substituted or unsubstituted carbazole group, provided that when R 4 When n is a substituted or unsubstituted amine group or a substituted or unsubstituted carbazole group, n 1 is an integer from 1 to 4, and when R5 When n is a substituted or unsubstituted amine group or a substituted or unsubstituted carbazole group, n 2 is an integer from 1 to 4; Y is a direct bond; and “a” is 0 or 1.

[0015] In an embodiment, the plurality of organic layers may include a hole transport region on the first electrode, an emission layer on the hole transport region, and an electron transport region on the emission layer. The emission layer may include a fused polycyclic compound represented by Formula 1.

[0016] In an embodiment, the emission layer may emit delayed fluorescence.

[0017] In an embodiment, the emission layer may be a delayed fluorescence emission layer including a first compound and a second compound. The second compound may include a condensed polycyclic compound represented by Formula 1.

[0018] In an embodiment, the emission layer may include a first compound having a first lowest triplet excitation energy level, a second compound having a second lowest triplet excitation energy level lower than the first lowest triplet excitation energy level, and a third compound having a third lowest triplet excitation energy level lower than the second lowest triplet excitation energy level. The second compound may include a fused polycyclic compound represented by Formula 1.

[0019] In an embodiment, the second compound may be a delayed fluorescent material. The third compound may be a phosphorescent material or a fluorescent material.

[0020] In an embodiment, the fused polycyclic compound represented by Formula 1 may be represented by the following Formula 3:

[0021] Formula 3

[0022]

[0023] In formula 3, R 11 To R 21 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms for forming a ring, and R 11 To R 21 Any one of may (optionally) combine with an adjacent group to form a ring, and R 11 To R 21 At least one of them can be represented by Formula 2 above.

[0024] In formula 3, M, X 1 and X 2 It may be the same as defined in Formula 1.

[0025] In an embodiment, the fused polycyclic compound represented by Formula 3 may be represented by the following Formula 4:

[0026] Formula 4

[0027]

[0028] In formula 4, R 31 To R 33 may each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 60 carbon atoms for forming a ring, and R 31 To R 33 Any one of may (optionally) combine with an adjacent group to form a ring, and R 31 To R 33 At least one of them can be represented by Formula 2 above.

[0029] In formula 4, M, X 1 and X 2 Same as defined in Formula 1.

[0030] In an embodiment, the substituent represented by Formula 2 may be represented by the following Formula 5-1 or Formula 5-2:

[0031] Formula 5-1

[0032]

[0033] Formula 5-2

[0034]

[0035] In Formula 5-1 and Formula 5-2, R 4 , R 5 、n 1 and n 2 Same as defined in Equation 2.

[0036] In an embodiment, the substituent represented by Formula 2 may be represented by any one of the following Formulas 6-1 to 6-4:

[0037] Formula 6-1

[0038]

[0039] Formula 6-2

[0040]

[0041] Formula 6-3

[0042]

[0043] Formula 6-4

[0044]

[0045] In equations 6-1 to 6-4, R 41 To R 46 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 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 60 carbon atoms for forming a ring, and R 41 To R 46 Any one of the groups may (optionally) combine with an adjacent group to form a ring, n 3 and n 4 are independently integers from 0 to 3, n 5 to n 8 are independently integers from 0 to 4, m 1 and m 2 are independently 0 or 1, and m 1 and m 2 At least one of them is 1(m 1 +m 2 ≠0).

[0046] In an embodiment, the substituent represented by Formula 2 may be represented by the following Formula 7-1 or Formula 7-2:

[0047] Formula 7-1

[0048]

[0049] Formula 7-2

[0050]

[0051] In equations 7-1 and 7-2, R 4 and R 5 Same as defined in Equation 2.

[0052] In an embodiment, X 1 and X 2 can be independently NR 1 or O, and R 1 The phenyl group may be substituted or unsubstituted.

[0053] In an embodiment, the first electrode and the second electrode each independently include at least one selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn, and Zn, or each independently includes at least one selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn, and Zn. A composite of two or more of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn and Zn, or an oxide of one or more selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn and Zn.

[0054] In an embodiment of the inventive concept, a fused polycyclic compound according to an embodiment may be represented by Formula 1 above. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0056] Figure 1 is a cross-sectional view schematically showing an organic electroluminescent device according to an embodiment of the inventive concept;

[0057] Figure 2 is a cross-sectional view schematically showing an organic electroluminescent device according to an embodiment of the inventive concept;

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

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

[0060] With reference to the accompanying drawings, through preferred exemplary (example) embodiments, the above purposes, other purposes, features and advantages of the inventive concept will be easily understood. However, the inventive concept can be implemented in different forms and should not be interpreted as being limited to the embodiments set forth herein. On the contrary, exemplary (example) embodiments are provided to make the contents disclosed herein thorough and complete, and the spirit of the inventive concept is fully accepted (obvious) by those skilled in the art.

[0061] In order to illustrate each figure, the same reference numerals refer to the same elements. In the accompanying drawings, in order to make the inventive concept clear, the size of the elements can be enlarged. It will be understood that although the terms first, second, etc. can be used to describe various elements here, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first element discussed below can be named as the second element, and similarly, the second element can be named as the first element. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form.

[0062] It will also be understood that when the terms "comprises" or "includes" and variations thereof are used in this specification, the stated features, numbers, steps, operations, elements, parts, or combinations thereof are indicated, but the presence or addition of one or more other features, numbers, steps, operations, elements, parts, or combinations thereof is not excluded. It will also be understood that when a layer, film, region, plate, etc. is referred to as "on" another component, the layer, film, region, plate, etc. may be "directly on" the other component, or an intermediate layer (or component) may also be present. Similarly, when a layer, film, region, plate, etc. is referred to as "below" another component, the layer, film, region, plate, etc. may be "directly below" the other component, or an intermediate layer (or component) may also be present. Conversely, when a layer, film, region, plate, etc. is referred to as "directly on" or "below" another component, an intermediate layer (or component) may not be present.

[0063] When expressions such as "at least one of", "one of", and "selected from" are placed after (before) a list of elements, they modify the entire list of elements rather than the individual elements in the list. In addition, the use of "may" when describing embodiments of the present invention refers to "one or more embodiments of the present invention".

[0064] Hereinafter, an organic electroluminescent device according to one or more embodiments of the inventive concept and a condensed polycyclic compound according to one or more embodiments included therein will be described with reference to the accompanying drawings.

[0065] Figures 1 to 42 is a cross-sectional view schematically showing an organic electroluminescent device according to an exemplary embodiment of the inventive concept. Figures 1 to 4 In the organic electroluminescent device 10 according to the embodiment, the first electrode EL1 and the second electrode EL2 are arranged (placed) opposite to each other, and a plurality of organic layers may be arranged between the first electrode EL1 and the second electrode EL2. The plurality of organic layers may include a hole transport region HTR, an emission layer EML, and an electron transport region ETR. That is, the organic electroluminescent device 10 of the embodiment may include a first electrode EL1, a hole transport region HTR, an emission layer EML, an electron transport region ETR, and a second electrode EL2 stacked one by one (sequentially). On the second electrode EL2, a cap layer CPL may also be arranged.

[0066] The organic electroluminescent device 10 of the present embodiment may include the fused polycyclic compound of the present embodiment, which will be described in more detail later, in at least one organic layer among the plurality of organic layers disposed between the first electrode EL1 and the second electrode EL2. For example, the organic electroluminescent device 10 of the present embodiment may include the fused polycyclic compound of the present embodiment in the emission layer EML disposed between the first electrode EL1 and the second electrode EL2. However, the embodiments of the inventive concept are not limited thereto, and the organic electroluminescent device 10 of the present embodiment may include the fused polycyclic compound of the present embodiment in at least one organic layer included in the hole transport region HTR and the electron transport region ETR among the plurality of organic layers other than the emission layer EML disposed between the first electrode EL1 and the second electrode EL2, or the fused polycyclic compound of the present embodiment may be located in the cap layer CPL disposed on the second electrode EL2.

[0067] Figure 2 A cross-sectional view of the organic electroluminescent device 10 of the present embodiment is shown, 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 3 1 shows a cross-sectional view of an organic electroluminescent device 10 of this embodiment, 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. Figure 2 When comparing, Figure 4 FIG. 4 is a cross-sectional view of an organic electroluminescent device 10 of the present embodiment, which includes a cap layer CPL disposed on the second electrode EL2 .

[0068] Hereinafter, in explaining the organic electroluminescent device 10 of the present embodiment, it is explained that the emission layer EML includes the condensed polycyclic compound according to the present embodiment, but the embodiments of the inventive concept are not limited thereto. The condensed polycyclic compound may be included in the hole transport region HTR, the electron transport region ETR, or the cap layer CPL.

[0069] The first electrode EL1 has 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 transflective 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 transflective electrode or a reflective electrode, the first electrode EL1 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). In one or more embodiments, the first electrode EL1 may have a structure including a plurality of layers, the plurality of layers including a reflective layer or a transflective layer formed using any one of the above materials and a transmissive conductive layer formed using ITO, IZO, ZnO and / or ITZO. For example, the first electrode EL1 may include a three-layer structure of ITO / Ag / ITO. However, embodiments of the inventive concept are not limited thereto. The thickness of the first electrode EL1 may be approximately To about For example, approximately To about

[0070] The hole transport region HTR is disposed on the first electrode EL1. The hole transport region HTR may include at least one of a hole injection layer HIL, a hole transport layer HTL, a hole buffer layer, and an electron blocking layer EBL. The thickness of the hole transport region HTR may be about 1000 Å. To about

[0071] 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-layer structure including a plurality of layers formed using a plurality of different materials.

[0072] 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 some embodiments, the hole transport region HTR may have a single-layer structure formed using a plurality of different materials, or 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, a hole injection layer HIL / hole buffer layer, a hole transport layer HTL / hole buffer layer, or a hole injection layer HIL / hole transport layer HTL / electron blocking layer EBL stacked from the first electrode EL1, but the present disclosure is not limited thereto.

[0073] The hole transport region HTR may be formed using one or more suitable methods such as a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, and / or a laser induced thermal imaging (LITI) method.

[0074] The hole injection layer HIL may include, for example, a phthalocyanine compound (such as copper phthalocyanine), N,N'-diphenyl-N,N'-bis[4-(di-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine (DNTPD), 4,4',4"-[tri(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4',4"-tri(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tri{N-(2-naphthyl)-N-phenylamino}-triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / dodecylbenzene Sulfonic acid (PANI / DBSA), polyaniline / camphorsulfonic acid (PANI / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine (NPB), N,N'-di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPD), triphenylamine-containing polyetherketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium [tetrakis(pentafluorophenyl)borate] and / or dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN).

[0075] The hole transport layer HTL may include, for example, carbazole derivatives (such as N-phenylcarbazole and / or polyvinylcarbazole), fluorene derivatives, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), triphenylamine derivatives (such as 4,4',4"-tri(N-carbazolyl)triphenylamine (TCTA)), N,N'-di(naphthalene-1-yl)-N,N'- diphenyl-benzidine (NPB), 4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4'-bis[N,N'-(3-methylphenyl)amino]-3,3'-dimethylbiphenyl (HMTPD), 1,3-bis(N-carbazolyl)benzene (mCP) and / or 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi), etc.

[0076] The thickness of the hole transport region HTR may be approximately To about For example, approximately To about The thickness of the hole injection layer HIL may be, for example, about To about The thickness of the hole transport layer HTL may 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 each independently satisfy the above range, satisfactory (or appropriate) hole transport performance may be achieved without significantly increasing driving voltage.

[0077] In addition to the above materials, the hole transport region HTR may further include a charge generating material to improve conductivity. The charge generating material may be uniformly or non-uniformly dispersed in the hole transport region HTR. The charge generating material may be, for example, a p-dopant. The p-dopant may be one of a quinone derivative, a metal oxide, and a cyano-containing compound, but the present disclosure is not limited thereto. Non-limiting examples of p-dopants may include quinone derivatives (such as tetracyanoquinodimethane (TCNQ) and / or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ)) and / or metal oxides (such as tungsten oxide and / or molybdenum oxide), but the present disclosure is not limited thereto.

[0078] 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 improve the luminous 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 is capable of preventing (or reducing) electrons from being injected into the hole transport region HTR from the electron transport region ETR.

[0079] The emission layer EML is disposed on the hole transport region HTR. The emission layer EML may have, for example, approximately To about (or approximately 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.

[0080] In the organic electroluminescent device 10 of the present embodiment, the emission layer EML may include the condensed polycyclic compound of the present embodiment.

[0081] In this manual, Indicates the connection part.

[0082] In this specification, the term "substituted or unsubstituted" corresponds to a group that is unsubstituted or substituted with at least one substituent when used in conjunction with a functional group, wherein the at least one substituent is selected from a deuterium atom, a halogen atom, a cyano group, a nitro group, an amino group, a silyl group, an oxygen (oxygen-containing) 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, a thiazolinyl group, an alkoxy group, a hydrocarbon ring group, an aryl group, and a heterocyclic group. In addition, each of the substituents listed can be substituted or unsubstituted. For example, a biphenyl group can be interpreted as an aryl group or a phenyl group substituted with a phenyl group.

[0083] In the present specification, the term "forming a ring by combining with an adjacent group" may refer to forming a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocyclic ring by combining one group with an adjacent group. The hydrocarbon ring may include an aliphatic hydrocarbon ring and an aromatic hydrocarbon ring. The heterocyclic ring may include an aliphatic heterocyclic ring and an aromatic heterocyclic ring. The ring formed by combining with an adjacent group may be a monocyclic ring or a polycyclic ring. In addition, the ring formed by combining with an adjacent group may be combined with another ring to form a spiro structure.

[0084] In the present specification, the term "adjacent groups" may refer to a pair of substituents in which a first substituent is connected to an atom directly connected to another atom substituted with a second substituent, a pair of substituents connected to the same atom, or a pair of substituents in which a first substituent is spatially located at the nearest position to a second substituent. For example, in 1,2-dimethylbenzene, two methyl groups may be interpreted as "adjacent groups" to each other, and in 1,1-diethylcyclopentane, two ethyl groups may be interpreted as "adjacent groups" to each other.

[0085] In the present specification, the halogen atom may be a fluorine atom, a chlorine atom, a bromine atom and / or an iodine atom.

[0086] In the present specification, the alkyl group may be a linear group, a branched group or a cyclic group. 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-butyldecyl, 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, but the present disclosure is not limited thereto.

[0087] In the present specification, hydrocarbon rings include aliphatic hydrocarbon rings and aromatic hydrocarbon rings. Heterocyclic rings include aliphatic heterocyclic rings and aromatic heterocyclic rings. The hydrocarbon rings and heterocyclic rings may be independently monocyclic or polycyclic.

[0088] In the present specification, the hydrocarbon ring group may refer to a functional group or substituent derived from an aliphatic hydrocarbon ring or a functional group or substituent derived from an aromatic hydrocarbon ring. The number of carbon atoms forming the ring in the hydrocarbon ring group (eg, the number of ring-forming carbon atoms) may be 5 to 60.

[0089] In the present specification, the heterocyclic group may be a functional group or a substituent derived from a heterocyclic ring including at least one heteroatom as a ring-forming element. The number of carbon atoms forming the ring in the heterocyclic group may be 2 to 60 (eg, 5 to 60).

[0090] In the present specification, an aryl group refers to a functional group or a substituent group 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 forming the ring in the aryl group may be 6 to 60, 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, benzo[9,10]phenanthrenyl, pyrenyl, benzofluoranthenyl, Base, etc., but the present disclosure is not limited thereto.

[0091] In the present specification, the fluorenyl group may be substituted, and two substituents of the fluorenyl group may be combined with each other to form a spiro structure. Examples of substituted fluorenyl groups are as follows. However, embodiments of the inventive concept are not limited thereto:

[0092]

[0093] In the present specification, the heteroaryl group may include one or more of B, O, N, P, Si and S as a ring-forming heteroatom. If the heteroaryl group includes 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 ring forming the heteroaryl group may be 2 to 60, 2 to 30, 2 to 20 or 2 to 10. Examples of heteroaryl groups may include thiophene, furan, pyrrole, imidazole, thiazole, oxazole, oxadiazole, triazole, pyridine, bipyridine, pyrimidine, triazine, acridine, pyridazine, pyrazine, quinoline, quinazoline, quinoxaline, phenoxazine, phthalazine, pyridopyrimidine, pyridopyrazine, pyrazinopyrazine, isoquinoline, indole, carbazole, N-arylcarbazole, N-heteroarylcarbazole, N-alkylcarbazole, benzoxazole, benzimidazole, benzothiazole, benzocarbazole, benzothiophene, dibenzothiophene, thienothiophene, benzofuran, phenanthroline, isoxazole, thiadiazole, phenothiazine, dibenzosilole, dibenzofuran, and the like, but the present disclosure is not limited thereto.

[0094] In the present specification, a silyl group may include an alkylsilyl group and an arylsilyl group. Examples of silyl groups may include trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, etc., but the present disclosure is not limited thereto. However, embodiments of the inventive concept are not limited thereto.

[0095] In the present specification, the boryl group may include an alkyl boryl group and an aryl boryl group. Examples of the boryl group include trimethyl boryl group, triethyl boryl group, tert-butyl dimethyl boryl group, triphenyl boryl group, diphenyl boryl group, phenyl boryl group, etc., but the present disclosure is not limited thereto.

[0096] In the present specification, the carbon number of the amine group (or amino group) is not particularly limited, but can be 1 to 30. The amine group can include an alkylamine group and an arylamine group. Examples of the amine group include a methylamine group, a dimethylamine group, a phenylamine group, a naphthylamine group, a 9-methyl-anthrylamine group, a diphenylamine group, etc., but the present disclosure is not limited thereto.

[0097] In the present specification, the hydrocarbon ring group means a functional group or a substituent group derived from an aliphatic hydrocarbon ring. The hydrocarbon ring may be a saturated hydrocarbon ring having 5 to 20 carbon atoms to form a ring.

[0098] In the present specification, the heterocyclic group may include one or more from B, O, N, P, Si and S as a heteroatom. If the heterocyclic group includes two or more heteroatoms, the two or more heteroatoms may be the same or different. The heterocyclic group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group, and may be a heteroaryl group. The carbon number of the ring forming the heterocyclic group may be 2 to 30, 2 to 20 or 2 to 10.

[0099] The fused polycyclic compound of this embodiment is represented by the following formula 1:

[0100] Formula 1

[0101]

[0102] In Formula 1, M is B, Al, Ga, or In. M may be any one of the elements of Group 13. For example, M may be boron (B).

[0103] In formula 1, X 1 and X 2 can be independently NR 1 ,O,S,P(=O)R 2 or P(=S)R 3 . R 1 To R 3and R are independently hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups of 1 to 20 carbon atoms, substituted or unsubstituted aryl groups of 6 to 60 carbon atoms for forming a ring, or substituted or unsubstituted heteroaryl groups of 2 to 60 carbon atoms for forming a ring. 1 To R 3 Any one of can be independently combined with the adjacent group to form a ring. 1 and X 2 can be independently NR 1 or O. For example, in the fused polycyclic compound represented by Formula 1, X 1 and X 2 Both can be NR 1 In some embodiments, X 1 and X 2 Both can be O. In some embodiments, X 1 and X 2 Any one of them can be NR 1 , and the other can be O. 1 and X 2 At least one of them is NR 1 In the case of R 1 It can be a substituted or unsubstituted phenyl group. For example, R 1 It can be unsubstituted phenyl. In some embodiments, R 1 It may be 1,3,5-trimethylphenyl.

[0104] In formula 1, Cy 1 To Cy 3 Cy may be independently a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring. 1 To Cy 3 can be independently a five-membered or six-membered substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocyclic ring. 1 To Cy 3 Each can independently combine with an adjacent group to form an additional ring. 1 To Cy 3 Each of them may independently be a substituted or unsubstituted six-membered aromatic hydrocarbon ring.

[0105] In formula 1, Cy 1 To Cy 3 At least one of them is substituted with a substituent represented by the following formula 2:

[0106] Formula 2

[0107]

[0108] In formula 2, R 4 and R 5 and R are independently hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted amine groups, substituted or unsubstituted alkyl groups of 1 to 20 carbon atoms, substituted or unsubstituted aryl groups of 6 to 60 carbon atoms for forming a ring, or substituted or unsubstituted heteroaryl groups of 2 to 60 carbon atoms for forming a ring. 4 and R 5 Each may independently combine with an adjacent group to form an additional ring.

[0109] R 4 and R 5 At least one of them may be a substituted or unsubstituted amine group or a substituted or unsubstituted carbazole group. 4 and R 5 Any one of them may be a substituted or unsubstituted N,N-diphenylamine group or a substituted or unsubstituted carbazole group. In some embodiments, R 4 and R 5 Both may be a substituted or unsubstituted N,N-diphenylamine group or a substituted or unsubstituted carbazole group.

[0110] In Formula 2, Y is a direct bond, and "a" is 0 or 1. If "a" is 0, the substituent represented by Formula 2 may be a substituted or unsubstituted N,N-diphenylamine group. If "a" is 1, the substituent represented by Formula 2 may be a substituted or unsubstituted carbazole group.

[0111] In formula 2, n 1 and n 2 can each independently be an integer from 0 to 4. If n 1 is 0, then the fused polycyclic compound according to the embodiment may not be R 4 Replace. 1 4 and all R 4 When the group is a hydrogen atom, it can be 1 The same is true for the case where n is 0. 1 is an integer of 2 or greater, then multiple R 4 The groups can be the same or multiple R 4 At least one of the groups may be different. 2 If R is 0, the fused polycyclic compound can be 5 Replace. 2 4 and all R 5 When the group is a hydrogen atom, it can be 2 The same is true for the case where n is 0. 2 is an integer of 2 or greater, then multiple R 5 The groups can be the same or multiple R 5At least one of the groups may be different.

[0112] In formula 2, n 1 and n 2 At least one of them is an integer of 1 or greater. 4 is a substituted or unsubstituted amine group or a substituted or unsubstituted carbazole group, then n 1 is an integer from 1 to 4. If R 5 is a substituted or unsubstituted amine group or a substituted or unsubstituted carbazole group, then n 2 is an integer of 1 to 4. That is, the fused polycyclic compound of the present embodiment may have a structure in which a first hetero substituent including nitrogen is substituted at the fused polycyclic ring structure and a second hetero substituent including nitrogen is additionally substituted at the first hetero substituent.

[0113] The fused polycyclic compound of the present embodiment includes a nitrogen-containing hetero substituent, which enhances the electron donor performance when compared with the polycyclic compound of the prior art including two nitrogen atoms and one boron atom in the core. In particular, the fused polycyclic compound of the present embodiment has a structure in which a first nitrogen-containing hetero substituent is substituted at the fused polycyclic ring and a second nitrogen-containing hetero substituent is additionally substituted at the first hetero substituent. In addition, the fused polycyclic compound of the present embodiment shows multiple resonances by forming a fused ring with multiple aromatic rings, thereby easily separating the HOMO state and the LUMO state in one molecule, and can be used as a material emitting delayed fluorescence. The fused polycyclic compound according to the embodiment includes a double nitrogen-containing hetero substituent, which enhances the electron donor performance when compared with the polycyclic compound of the prior art including two nitrogen atoms and one boron atom, and the fused polycyclic compound according to the embodiment can have a reduced difference (△E between the lowest triplet excitation energy level (T1 energy level) and the lowest singlet excitation energy level (S1 energy level) ST ). Therefore, if the fused polycyclic compound of the present embodiment is used as a material for emitting delayed fluorescence, the emission efficiency of the organic electroluminescent device can be even further improved.

[0114] The fused polycyclic compound represented by Formula 1 may be represented by the following Formula 3:

[0115] Formula 3

[0116]

[0117] In formula 3, R 11 To R 21and R are independently hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted amine groups, substituted or unsubstituted alkyl groups of 1 to 20 carbon atoms, substituted or unsubstituted aryl groups of 6 to 60 carbon atoms for forming a ring, or substituted or unsubstituted heteroaryl groups of 2 to 60 carbon atoms for forming a ring. 11 To R 21 Any of the groups may independently combine with adjacent groups to form additional rings.

[0118] R 11 To R 21 At least one of them can be represented by Formula 2. For example, R 12 , R 15 and R 20 At least one of them can be represented by Formula 2. 12 , R 15 and R 20 At least one of them may be a substituted or unsubstituted amine group or a substituted or unsubstituted carbazole group. 12 , R 15 and R 20 At least one of them may be a substituted or unsubstituted N,N-diphenylamine group or a substituted or unsubstituted carbazole group. 12 , R 15 and R 20 At least one of them may be an unsubstituted N,N-diphenylamino group, an N,N-diphenylamino group substituted with a substituted or unsubstituted carbazolyl group, or a substituted or unsubstituted carbazolyl group.

[0119] At the same time, in Formula 3, the formulas about M and X provided in Formula 1 can be applied. 1 and X 2 The same explanation.

[0120] The fused polycyclic compound represented by Formula 3 may be represented by the following Formula 4:

[0121] Formula 4

[0122]

[0123] In formula 4, R 31 To R 33 and R are independently hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted amine groups, substituted or unsubstituted alkyl groups of 1 to 20 carbon atoms, substituted or unsubstituted aryl groups of 6 to 60 carbon atoms for forming a ring, or substituted or unsubstituted heteroaryl groups of 2 to 60 carbon atoms for forming a ring. 31 To R 33 Any of the groups may independently combine with adjacent groups to form additional rings.

[0124] R 31 To R 33 At least one of them can be represented by Formula 2. 31 To R 33 At least one of them may be a substituted or unsubstituted amine group or a substituted or unsubstituted carbazole group. 31 To R 33 At least one of them may be a substituted or unsubstituted N,N-diphenylamine group or a substituted or unsubstituted carbazole group. 31 To R 33 At least one of them may be an unsubstituted N,N-diphenylamino group, an N,N-diphenylamino group substituted with a substituted or unsubstituted carbazolyl group, or a substituted or unsubstituted carbazolyl group.

[0125] At the same time, in Formula 4, the formulas about M and X provided in Formula 1 can be applied. 1 and X 2 The same explanation.

[0126] In Formula 1, the substituent represented by Formula 2 may be represented by the following Formula 5-1 or Formula 5-2:

[0127] Formula 5-1

[0128]

[0129] Formula 5-2

[0130]

[0131] Formula 5-1 may correspond to Formula 2 where "a" is 0. Formula 5-2 may correspond to Formula 2 where "a" is 1.

[0132] At the same time, in Formula 5-1 and Formula 5-2, the formula for R provided in Formula 2 can be applied 4 , R 5 、n 1 and n 2 The same explanation.

[0133] The substituent represented by Formula 2 may be represented by any one of the following Formulas 6-1 to 6-4:

[0134] Formula 6-1

[0135]

[0136] Formula 6-2

[0137]

[0138] Formula 6-3

[0139]

[0140] Formula 6-4

[0141]

[0142] In equations 6-1 to 6-4, R 41 To R 46 and R are independently hydrogen atoms, deuterium atoms, halogen atoms, substituted or unsubstituted alkyl groups of 1 to 20 carbon atoms, substituted or unsubstituted aryl groups of 6 to 60 carbon atoms for forming a ring, or substituted or unsubstituted heteroaryl groups of 2 to 60 carbon atoms for forming a ring. 41 To R 46 Any of the R groups can independently combine with adjacent groups to form additional rings. 41 To R 46 All of the atoms in may be hydrogen atoms.

[0143] In equations 6-1 to 6-4, n 3 and n 4 can each independently be an integer from 0 to 3. If n 3 is 0, then the fused polycyclic compound according to the embodiment may not be R 41 Replace. If n 3 is an integer of 2 or greater, then multiple R 41 The groups can be the same or multiple R 41 At least one of the groups may be different. 4 If R is 0, the fused polycyclic compound can be 42 Replace. If n 4 is an integer of 2 or greater, then multiple R 42 The groups can be the same or multiple R 42 At least one of the groups may be different.

[0144] In equations 6-1 to 6-4, n 5 to n 8 can each independently be an integer from 0 to 4. If n 5 is 0, then the fused polycyclic compound according to the embodiment may not be R 43 Replace. If n 5 is an integer of 2 or greater, then multiple R 43 The groups can be the same or multiple R 43 At least one of the groups may be different. 6 If R is 0, the fused polycyclic compound can be 44 Replace. If n 6 is an integer of 2 or greater, then multiple R 44 The groups can be the same or multiple R44 At least one of the groups may be different. 7 If R is 0, the fused polycyclic compound can be 45 Replace. If n 7 is an integer of 2 or greater, then multiple R 45 The groups can be the same or multiple R 45 At least one of the groups may be different. 8 If R is 0, the fused polycyclic compound can be 46 Replace. If n 8 is an integer of 2 or greater, then multiple R 46 The groups can be the same or multiple R 46 At least one of the groups may be different.

[0145] In equations 6-1 to 6-4, m 1 and m 2 can all be independently 0 or 1. In this case, m 1 +m 2 ≠0, that is, m 1 and m 2 At least one of them can be 1. Excluding m 1 and m 2 In one or more embodiments, m 1 and m 2 One of them may be 1, and the other may be 0. In some embodiments, m 1 and m 2 Both can be 1.

[0146] The substituent represented by Formula 2 may be represented by the following Formula 7-1 or Formula 7-2:

[0147] Formula 7-1

[0148]

[0149] Formula 7-2

[0150]

[0151] In equations 7-1 and 7-2, the formula for R provided in equation 2 can be applied. 4 and R 5 The same explanation.

[0152] The condensed polycyclic compound of the present embodiment may be any one of the compounds represented in the following compound group 1. The organic electroluminescent device 10 of the present embodiment may include at least one condensed polycyclic compound among the compounds represented in the compound group 1 in the emission layer EML.

[0153] Compound Group 1

[0154]

[0155]

[0156]

[0157]

[0158] The fused polycyclic compound represented by Formula 1 of the present embodiment may be a thermally activated delayed fluorescent emission material. In addition, the fused polycyclic compound represented by Formula 1 of the present embodiment may have a difference (ΔE) between the lowest triplet excitation energy level (T1 level) and the lowest singlet excitation energy level (S1 level) of about 0.4 eV or less. ST )'s thermally activated delayed fluorescence dopant.

[0159] The fused polycyclic compound represented by Formula 1 of the present embodiment may be a luminescent material having a luminescent center wavelength in a wavelength region of about 430 nm to about 490 nm. For example, the fused polycyclic compound represented by Formula 1 of the present embodiment may be a blue thermally activated delayed fluorescence (TADF) dopant. However, the embodiments of the inventive concept are not limited thereto, and in the case of using the fused polycyclic compound of the present embodiment as a luminescent material, the fused polycyclic compound may be used as a dopant material emitting light in various suitable wavelength regions, such as a red emission dopant and / or a green emission dopant.

[0160] In the organic electroluminescent device 10 of the present embodiment, the emission layer EML may emit delayed fluorescence. For example, the emission layer EML may emit thermally activated delayed fluorescence (TADF).

[0161] In addition, the organic electroluminescent device 10 may emit blue light. For example, the emission layer EML of the organic electroluminescent device 10 of the present embodiment may emit blue light in the range of about 490 nm or more. However, embodiments of the inventive concept are not limited thereto, and the emission layer EML may emit green light or red light.

[0162] The organic electroluminescent device 10 of the present embodiment may include a plurality of emission layers. The plurality of emission layers may be stacked one by one (sequentially). For example, the organic electroluminescent device 10 (including a plurality of emission layers) may emit white light. The organic electroluminescent device 10 (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 fused polycyclic compound of the present embodiment.

[0163] In an embodiment, the emission layer EML includes a host and a dopant, and may include the fused polycyclic compound of the present embodiment as a dopant. For example, in the organic electroluminescent device 10 of the present embodiment, the emission layer EML may include a host for emitting delayed fluorescence and a dopant for emitting delayed fluorescence, and may include a fused polycyclic compound as a dopant for emitting delayed fluorescence. The emission layer EML may include at least one of the fused polycyclic compounds represented in compound group 1 as a thermally activated delayed fluorescence dopant.

[0164] In one or more embodiments, the emission layer EML may be a delayed fluorescent emission layer, and the emission layer EML may include any suitable host material and the above-mentioned fused polycyclic compound. For example, in an embodiment, the fused polycyclic compound may be used as a TADF dopant.

[0165] As the host material of the emission layer EML, any suitable material may be used, and without particular limitation, may be selected from fluoranthene derivatives, pyrene derivatives, arylacetylene derivatives, anthracene derivatives, fluorene derivatives, perylene derivatives, Derivatives, etc. In one or more embodiments, pyrene derivatives, perylene derivatives and / or anthracene derivatives may be used. For example, an anthracene derivative represented by the following Formula 8 may be used as a host material of the emission layer EML:

[0166] Formula 8

[0167]

[0168] In formula 8, W 1 To W 4 and W are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted silyl group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 30 carbon atoms for forming a ring, and W 1 To W 4 Any one of may combine with an adjacent group to form a ring. m1 and m2 may each independently be an integer of 0 to 4, and m3 and m4 may each independently be an integer of 0 to 5.

[0169] When m1 is 1, W 1 It may not be a hydrogen atom. When m2 is 1, W 2 It may not be a hydrogen atom. When m3 is 1, W 3 It may not be a hydrogen atom. When m4 is 1, W 4 It may not be a hydrogen atom.

[0170] In the case where m1 is 2 or greater, multiple W1 The groups are the same or different. In the case where m2 is 2 or greater, multiple W 2 The groups are the same or different. In the case where m3 is 2 or greater, multiple W 3 The groups are the same or different. In the case where m4 is 2 or greater, multiple W 4 The groups may be the same or different.

[0171] The compound represented by Formula 8 may include, for example, a compound represented by the following structure. However, examples of the compound represented by Formula 8 are not limited thereto.

[0172]

[0173] In one or more embodiments, the emission layer EML may include tris(8-hydroxyquinoline)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(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 2-tert-butyl-9,10-di(naphthalene-2-yl)anthracene (TBADN), diphenylethylene 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. are used as host materials. However, embodiments of the inventive concept are not limited thereto. Any suitable host material for emitting delayed fluorescence other than the given host material may be included.

[0174] Meanwhile, in the organic electroluminescent device 10 of the present embodiment, the emission layer EML may further include any suitable dopant material. In one or more embodiments, the emission layer EML may include styryl derivatives (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]stilbene (DPAVB) and / or N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalene-2-yl)vinyl)phenyl)-N-phenylaniline (N-BDAVBi)), perylene and its derivatives (e.g., 2,5,8,11-tetra-tert-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1'-dipyrene, 1,4-dipyrenylbenzene and / or 1,4-bis(N,N-diphenylamino)pyrene), etc. as dopants.

[0175] In one or more embodiments, the emission layer EML may include two dopant materials having different lowest triplet excitation energy levels (T1 levels) from each other. In the organic electroluminescent device 10 of the present embodiment, the emission layer EML may include a host having a first lowest triplet excitation energy level, a first dopant having a second lowest triplet excitation energy level lower than the first lowest triplet excitation energy level, and a second dopant having a third lowest triplet excitation energy level lower than the second lowest triplet excitation energy level. In one or more embodiments, the emission layer EML may include the above-mentioned fused polycyclic compound of the present embodiment as a first dopant.

[0176] In the organic electroluminescent device 10 of the present embodiment including a host, a first dopant, and a second dopant in the emission layer EML, the first dopant may be a delayed fluorescence dopant, and the second dopant may be a fluorescent dopant. In addition, in the organic electroluminescent device 10 of the present embodiment, the fused polycyclic compound represented by Formula 1 may play the role of an auxiliary dopant.

[0177] For example, in the case where the emission layer EML of the organic electroluminescent device 10 of the present embodiment includes a plurality of dopants, the emission layer EML may include the fused polycyclic compound of the present embodiment as a first dopant and the above-mentioned dopant material as a second dopant. For example, in the case where the emission layer EML emits blue light, the emission layer EML may further include any one selected from styryl derivatives (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]stilbene (DPAVB) and / or N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalene-2-yl)vinyl)phenyl)-N-phenylaniline (N-BDAVBi)), perylene and 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), etc. as the second dopant. In addition, a metal complex and / or an organic metal complex including Ir, Pt, Pd, etc. as a core atom may be used as the second dopant.

[0178] Meanwhile, in the organic electroluminescent device 10 of the present embodiment including the fused polycyclic compound of the present embodiment as the first dopant of the emission layer EML, the emission layer EML can emit green light or red light, and in this case, the second dopant material used can be the above-mentioned dopant, a suitable green fluorescent dopant or a suitable red fluorescent dopant.

[0179] In the organic electroluminescent device 10 of the present embodiment, the emission layer EML may be a phosphorescent emission layer. For example, the condensed polycyclic compound according to the present embodiment may be included in the emission layer EML as a phosphorescent host material.

[0180] In the organic electroluminescent device 10 of this embodiment, as in Figures 1 to 4 As shown in FIG. 1 , the electron transport region ETR is disposed on the emission layer EML. The electron transport region ETR may include at least one of an electron blocking layer HBL, an electron transport layer ETL, and an electron injection layer EIL. However, embodiments of the inventive concept are not limited thereto.

[0181] 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 multilayer structure including a plurality of layers formed using a plurality of different materials.

[0182] For example, the electron transport region ETR may have a single-layer structure of an electron injection layer EIL or an electron transport layer ETL, or may have a single-layer structure formed using an electron injection material and an electron transport material. In addition, the electron transport region ETR may have a single-layer structure including a plurality of different materials, or 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 from an emission layer EML, but the present disclosure is not limited thereto. The thickness of the electron transport region ETR may be, for example, about 1000 Å. To about

[0183] The electron transport region ETR may be formed using one or more suitable methods such as a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, and / or a laser induced thermal imaging (LITI) method.

[0184] 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 ETR may include, for example, tris(8-hydroxyquinoline)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 (Bp hen), 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-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), bis(benzoquinoline-10-hydroxy)beryllium (Bebq 2 ), 9,10-di(naphthalene-2-yl)anthracene (ADN), diphenyl(4-(triphenylsilyl)phenyl)phosphine oxide (TSPO1), or a mixture thereof, but the present disclosure is not limited thereto. The thickness of the electron transport layer ETL may be about To about and can be, for example, approximately To about If the thickness of the electron transport layer ETL satisfies the above range, satisfactory (or appropriate) electron transport performance may be obtained without significantly increasing driving voltage.

[0185] If the electron transport region ETR includes an electron injection layer EIL, the electron transport region ETR may include a metal halide (such as LiF, NaCl, CsF, RbCl, RbI, and / or CuI), a lanthanide metal (such as Yb), a metal oxide (such as Li 2 O and / or BaO) and / or lithium hydroxyquinoline (LiQ). However, the embodiments of the inventive concept are not limited thereto. The electron injection layer EIL may also be formed using a mixed material of an electron transport material and an insulating organic metal salt. The organic metal salt may be a material having an energy band gap of about 4 eV or greater. The organic metal salt may include, for example, metal acetates, metal benzoates, metal acetoacetates, metal acetylacetonates and / or metal stearates. The thickness of the electron injection layer EIL may be about 1000 Å. To about and can be approximately To about If the thickness of the electron injection layer EIL satisfies the above range, satisfactory (or appropriate) electron injection performance may be obtained without significantly increasing driving voltage.

[0186] 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). However, embodiments of the inventive concept are not limited thereto.

[0187] The second electrode EL2 is disposed 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 transflective electrode or a reflective electrode. If the second electrode EL2 is a transmissive electrode, the second electrode EL2 may include a transparent metal oxide, for example, ITO, IZO, ZnO, ITZO, etc.

[0188] If the second electrode EL2 is a transflective electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, 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 transflective layer formed using any of the above materials and a transparent conductive layer formed using ITO, IZO, ZnO, ITZO, or the like.

[0189] 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.

[0190] Meanwhile, a cap layer CPL may be disposed on the second electrode EL2 of the organic electroluminescent device 10 of the present embodiment. The cap layer CPL 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.

[0191] The organic electroluminescent device 10 according to the embodiment of the inventive concept includes the fused polycyclic compound of the present embodiment in the emission layer EML disposed between the first electrode EL1 and the second electrode EL2, thereby showing high emission efficiency performance. In addition, the fused polycyclic compound according to the present embodiment may be a thermally activated delayed fluorescence dopant, and the emission layer EML may include the fused polycyclic compound of the present embodiment to emit thermally activated delayed fluorescence. Therefore, high emission efficiency performance can be achieved.

[0192] The fused polycyclic compound of the present 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 an embodiment of the inventive concept may include the fused polycyclic compound in at least one organic layer disposed between the first electrode EL1 and the second electrode EL2, or may include the fused polycyclic compound in a cap layer CPL disposed on the second electrode EL2.

[0193] When compared with the polycyclic compound including two nitrogen atoms and one boron atom in the prior art, the fused polycyclic compound of the present embodiment includes a double nitrogen-containing hetero substituent obtained by additionally substituting a nitrogen-containing second hetero substituent at a nitrogen-containing first hetero substituent, and the fused polycyclic compound of the present embodiment can relatively reduce the difference (ΔE ) between the lowest triplet excitation energy level (T1 energy level) and the lowest singlet excitation energy level (S1 energy level). ST ). Therefore, if the fused polycyclic compound of this embodiment is used as a material for an organic electroluminescent device, the efficiency of the organic electroluminescent device can be further improved.

[0194] Hereinafter, the fused polycyclic compound according to the embodiment of the inventive concept and the organic electroluminescent device of the present embodiment will be specifically explained with reference to specific examples and comparative examples. The following examples are only examples for helping to understand the inventive concept, and the scope of the inventive concept is not limited thereto.

[0195] Example

[0196] 1. Synthesis of fused polycyclic compounds

[0197] First, the synthesis (making) method of the fused polycyclic compound according to the embodiment will be specifically described with reference to the synthesis methods of Compound 1, Compound 7, Compound 20 and Compound 21. However, the synthesis method of the fused polycyclic compound described below is only an example embodiment, and the synthesis method of the fused polycyclic compound according to the embodiment of the inventive concept is not limited thereto.

[0198] (1) Synthesis of Compound 1

[0199] The condensed polycyclic compound 1 according to the example can be synthesized, for example, through the following reaction 1 and reaction 2.

[0200] Synthesis of intermediate compound I-1

[0201] Reaction 1

[0202]

[0203] Synthesis of compound 1

[0204] Reaction 2

[0205]

[0206] 9.08 g (10 mmol) of 5-(9'H-[9,3':6',9"-tert-carbazole]-9'-yl)-N1,N1,N3,N3-tetraphenylbenzene-1,3-diamine was dissolved in 60 mL of 1,2-dichlorobenzene and BBr was added at about 0 °C. 3 (30 mmol). Then, the reactant was stirred at about 150° C. for about 15 hours, and the temperature was lowered to room temperature. Water was added thereto, and washed three times with 30 mL of dichloromethane. The dichloromethane layer thus washed was washed with MgSO 4 The reaction mixture was dried, the solvent was evaporated, and the crude product was separated by silica gel chromatography to obtain 3.66 g (yield 40%) of compound 1. 1 The results confirmed by H NMR showed that the product thus prepared had C 66 H 42 BN 5 The molecular formula of 2-nitropropene and the molecular weight of 1-nitropropene were 1.04 and 1.31, respectively.

[0207] (2) Synthesis of Compound 7

[0208] The condensed polycyclic compound 7 according to the example can be synthesized, for example, through the following reactions 3 and 4.

[0209] Synthesis of intermediate compound I-2

[0210] Reaction 3

[0211]

[0212] Synthesis of compound 7

[0213] Reaction 4

[0214]

[0215] In addition to using diphenylamine instead of carbazole in reaction 1, using 2,4,6-trimethyl-N-phenylaniline instead of diphenylamine in reaction 2, and using 9.96 g (10 mmol) of 9-(3,5-bis(mesityl(phenyl)amino)phenyl)-N3,N3,N6,N6-tetraphenyl-9H-carbazole-3,6-diamine and BBr 3 In addition to 1477 g (30 mmol), 3.68 g (yield 36%) of compound 7 was synthesized by the same (or substantially the same) method as that used to synthesize compound 1. 1 The results confirmed by H NMR showed that the product thus prepared had C 72 H 58 BN 5 The molecular formula of 1,4-dihydro-1-nitropropene and the molecular weight of 1,003.50 were determined.

[0216] (3) Synthesis of Compound 20

[0217] The condensed polycyclic compound 20 according to the embodiment can be synthesized, for example, through the following reaction 5.

[0218] React 5

[0219]

[0220] In the fourth step, the intermediate compound I-2 prepared in reaction 3 is used.

[0221] 10.92 g (10 mmol) of 9-(3,5-bis(3-(9H-carbazole-9-yl)phenoxy)phenyl)-N3,N3,N6,N6-tetraphenyl-9H-carbazole-3,6-diamine was dissolved in 60 mL of o-xylene, and 10 mL (25 mmol) of 2.5 M n-BuLi was added at about -30°C. Then, the reactants were stirred at about 70°C for about 1 hour, and BBr was added dropwise at about 0°C. 3(30 mmol). The reactant was stirred at about 150° C. for about 15 hours, and the temperature was lowered to room temperature. Water was added thereto, and washed three times with 30 mL of ethyl acetate. The ethyl acetate layer thus washed was washed with MgSO 4 The solvent was evaporated and the crude product was separated by silica gel chromatography to obtain 201.1 g (yield 10%) of compound 20. 1 The results confirmed by H NMR showed that the product thus prepared had C 78 H 50 BN 5 O 2 The molecular formula of 20 and the molecular weight of 1099.45 were determined.

[0222] (4) Synthesis of Compound 21

[0223] The condensed polycyclic compound 21 according to the example can be synthesized, for example, by the following reaction 6.

[0224] Reaction 6

[0225]

[0226] Compared with Reaction 5, 9H-3,9′-bicarbazole is used in Reaction 6 instead of carbazole, and carbazole is used in the fourth step instead of the intermediate compound I-2.

[0227] The reaction mixture was prepared by using 9.23 g (10 mmol) of 9-(3-(3-(3-(9H-carbazol-9-yl)phenoxy)-5-(9H-carbazol-9-yl)phenoxy)phenyl)-9H-3,9'-bicarbazole, 10 mL (25 mmol) of 2.5 M n-BuLi and BBr 3 (30 mmol), 0.75 g (yield 8%) of compound 21 was synthesized by the same (or substantially the same) method as that used to synthesize compound 20. 1 The results confirmed by H NMR showed that the product thus prepared had C 66 H 39 BN 4 O 2 The molecular formula of 21 and the molecular weight of 930.36 were determined.

[0228] 2. Evaluation of energy levels of fused polycyclic compounds

[0229] The compounds used in Examples 1 to 4 and Comparative Examples 1 to 8 are shown in Table 1.

[0230] Table 1

[0231]

[0232]

[0233] In the following Table 2, the lowest singlet excitation energy level (S1 level), the lowest triplet excitation energy level (T1 level) and ΔE of Compound 1, Compound 7, Compound 20 and Compound 21 (which are exemplary compounds) and Comparative Compounds C1 to C8 are shown. ST The energy level values ​​in Table 2 were calculated by the non-empirical molecular orbital method. Specifically, the calculation was performed using Gaussian 09 of Gauss Company using B3LYP / 6-31G(d). ΔE ST It represents the difference between the lowest singlet excited energy level (S1 level) and the lowest triplet excited energy level (T1 level).

[0234] Table 2

[0235] Classification Compound Type S1 energy level (eV) T1 energy level (eV) <![CDATA[ΔE ST (eV)]]> Example 1 Compound 1 2.99 2.64 0.35 Example 2 Compound 7 2.88 2.64 0.24 Example 3 Compound 20 2.20 2.16 0.04 Example 4 Compound 21 2.72 2.67 0.05 Comparative Example 1 Comparative Compound C1 2.82 2.73 0.09 Comparative Example 2 Comparative Compound C2 2.93 2.55 0.38 Comparison Example 3 Comparative Compound C3 3.06 2.61 0.45 Comparison Example 4 Comparative Compound C4 3.11 2.93 0.18 Comparative Example 5 Comparative Compound C5 3.15 2.84 0.31 Comparative Example 6 Comparative Compound C6 2.79 2.65 0.14 Comparative Example 7 Comparative Compound C7 3.01 2.60 0.41 Comparative Example 8 Comparative Compound C8 3.13 2.64 0.49

[0236] It was confirmed that Compound 1, Compound 7, Compound 20, and Compound 21, which are exemplary compounds, showed small ΔE ST Since Compound 1, Compound 7, Compound 20, and Compound 21 as example compounds show a small ΔE of about 0.4 eV or less ST values, so these compounds can be used as dopant materials for thermally activated delayed fluorescence with high light efficiency.

[0237] 3. Fabrication and evaluation of organic electroluminescent devices containing fused polycyclic compounds

[0238] Fabrication of organic electroluminescent devices

[0239] The organic electroluminescent device of this embodiment including the fused polycyclic compound of this embodiment in the emission layer is manufactured by the method described below. The fused polycyclic compounds of Compound 1, Compound 7, Compound 20 and Compound 21 as the example compounds are used as the dopant material of the emission layer to manufacture the organic electroluminescent devices of Examples 1 to 4. The organic electroluminescent devices of Comparative Examples 1 to 8 are manufactured using Comparative Compounds C1 to C8 as the dopant material in the emission layer.

[0240] On a glass substrate, there will be approximately The ITO with a thickness of 1000 nm was patterned and washed with isopropyl alcohol and ultrapure water, ultrasonically washed for about 5 minutes, exposed to UV for about 30 minutes, and treated with ozone. Then, NPD was vacuum deposited to about To form a hole injection layer, TCTA was vacuum deposited to a thickness of about The thickness of CzSi is vacuum deposited to about to form a hole transport layer.

[0241] The mCP and the fused polycyclic compound of the present embodiment of the inventive concept or the comparative compound were co-deposited on the hole transport layer at a ratio of 99:1 to form a The emission layer formed by co-deposition was formed by mixing Compound 1, Compound 7, Compound 20 and Compound 21 with mCP, respectively, to prepare Examples 1 to 4, respectively, or the emission layer formed by co-deposition was formed by mixing Comparative Compounds C1 to C8 with mCP, respectively, to prepare Comparative Examples 1 to 8, respectively.

[0242] TSPO1 is used to form a layer with a thickness of about Then, by sequentially depositing TPBi to about and depositing Yb to a thickness of approximately Then, an electron injection layer with a thickness of about 1000 mm was formed on the electron injection layer using aluminum (Al). The second electrode.

[0243] The compounds used in the Examples and Comparative Examples are shown below.

[0244]

[0245] Evaluation of the performance of organic electroluminescent devices

[0246] In Table 3, there are shown evaluation results of the organic electroluminescent devices of Examples 1 to 4 and Comparative Examples 1 to 8. In Table 3, the driving voltage, emission efficiency, and external quantum efficiency (EQE) of the organic electroluminescent devices thus manufactured are compared and shown.

[0247] In the evaluation results about the performance of the examples and comparative examples, as shown in Table 3, the voltage and current density were measured using a source meter (Keithley Instrument Co., 2400 series), and the external quantum efficiency (EQE) was measured using an external quantum efficiency measurement device C9920-12 of Hamamatsu Photonics Co. The emission efficiency is expressed relative to 10 mA / cm 2 The current efficiency value of the current density.

[0248] Table 3

[0249]

[0250]

[0251] Referring to the results in Table 3, when compared with the comparative example, it is found that the organic electroluminescent device according to the example using the fused polycyclic compound according to the embodiment of the inventive concept as the material of the emission layer shows a lower driving voltage value and higher emission efficiency and external quantum efficiency. In the case of the example compound, the TADF performance is exhibited by utilizing the multiple resonance phenomenon due to the aromatic ring forming the fused ring, and a small ΔE can be obtained by including a double nitrogen-containing hetero substituent. ST The dinitrogen-containing hetero substituent is obtained by replacing a nitrogen-containing first hetero substituent with a nitrogen-containing second hetero substituent substituted thereon at the ring forming the fused ring. Therefore, the organic electroluminescent device of the example can show improved emission efficiency compared with the organic electroluminescent device of the comparative example. In particular, by including the fused polycyclic compound of the present embodiment as a material for the emission layer, the organic electroluminescent device of the present embodiment can achieve high emission efficiency in the blue light wavelength region.

[0252] The organic electroluminescent device of the present embodiment can show improved device characteristics showing high emission efficiency in the blue wavelength region.

[0253] The fused polycyclic compound of the present embodiment may be included in an emission layer of an organic electroluminescent device and may help improve the efficiency of the organic electroluminescent device.

[0254] Although exemplary (example) embodiments of the present invention have been described, it is understood that the present invention should not be limited to these exemplary (example) embodiments, but rather, a person skilled in the art may make various changes and modifications within the spirit and scope of the present invention as defined by the claims and their equivalents.

Claims

1. An organic electroluminescent device, comprising: a first electrode; a second electrode, facing the first electrode; as well as A plurality of organic layers are located between the first electrode and the second electrode, The plurality of organic layers include: a hole transport region located on the first electrode; an emission layer located on the hole transport region; and an electron transport region located on the emission layer, and The emission layer is a delayed fluorescence emission layer including a first compound as a host and a second compound as a delayed fluorescence dopant, and The second compound includes a fused polycyclic compound represented by Formula 1: Formula 1 Among them, in formula 1, M is B, Al, Ga or In, X1 and X2 are independently NR1, O, S, P(=O)R2 or P(=S)R3, R1 to R3 are each independently 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 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 60 carbon atoms for forming a ring, and any one of R1 to R3 may optionally combine with an adjacent group to form a ring, Cy1 to Cy3 are each independently a substituted or unsubstituted aromatic hydrocarbon ring or a substituted or unsubstituted aromatic heterocycle, and any one of Cy1 to Cy3 may optionally combine with an adjacent group to form a ring, and At least one of Cy1 to Cy3 is substituted with a substituent represented by Formula 2: Formula 2 Among them, in formula 2, R4 and R5 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 60 carbon atoms for forming a ring, and any one of R4 and R5 is optionally combined with an adjacent group to form a ring, n1 and n2 are each independently an integer from 0 to 4, At least one of R4 and R5 is a substituted or unsubstituted amine group or a substituted or unsubstituted carbazole group, If R4 is the substituted or unsubstituted amine group or the substituted or unsubstituted carbazole group, n1 is an integer from 1 to 4, If R5 is the substituted or unsubstituted amine group or the substituted or unsubstituted carbazole group, n2 is an integer from 1 to 4, Y is a direct key, and a is 0 or 1.

2. The organic electroluminescent device according to claim 1, wherein: The emission layer further includes a third compound different from the first compound and the second compound, and The first compound has a first lowest triplet excited energy level, The second compound has a second lowest triplet excitation energy level lower than the first lowest triplet excitation energy level, and The third compound has a third lowest triplet excitation energy level lower than the second lowest triplet excitation energy level.

3. The organic electroluminescent device according to claim 2, wherein: The third compound is a phosphorescent material or a fluorescent material.

4. The organic electroluminescent device according to claim 1, wherein: The first compound includes fluoranthene derivatives, pyrene derivatives, arylacetylene derivatives, anthracene derivatives, fluorene derivatives, perylene derivatives, derivatives, tris(8-hydroxyquinoline)aluminum, 4,4'-bis(N-carbazolyl)-1,1'-biphenyl, poly(N-vinylcarbazole), 9,10-di(naphthalene-2-yl)anthracene, 4,4',4"-tri(carbazol-9-yl)-triphenylamine, 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene, 2-tert-butyl-9,10-di(naphthalene-2-yl)anthracene, distyryl arylide, 4,4'-bis(9-carbazolyl)anthracene At least one of bis(triphenylsilyl)benzene, 2,8-bis(diphenylphosphino)dibenzofuran, 3,3'-bis(N-carbazolyl)-1,1'-biphenyl and 1,3-bis(N-carbazolyl)benzene.

5. The organic electroluminescent device according to claim 1, wherein: The second compound is represented by Formula 3: Formula 3 Among them, in formula 3, R 11 To R 21 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 60 carbon atoms for forming a ring, and R 11 To R 21 Any one of which is optionally combined with an adjacent group to form a ring, R 11 To R 21 At least one of them is represented by Formula 2, and M, X1 and X2 are the same as defined in Formula 1.

6. The organic electroluminescent device according to claim 5, wherein: The second compound is represented by Formula 4: Formula 4 Among them, in formula 4, R 31 To R 33 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 60 carbon atoms for forming a ring, and R 31 To R 33 Any one of which is optionally combined with an adjacent group to form a ring, R 31 To R 33 At least one of them is represented by Formula 2, and M, X1 and X2 are the same as defined in Formula 1.

7. The organic electroluminescent device according to claim 1, wherein: The substituent represented by Formula 2 is represented by Formula 5-1 or Formula 5-2: Formula 5-1 Formula 5-2 Among them, in formula 5-1 and formula 5-2, R4, R5, n1 and n2 are the same as defined in Formula 2.

8. The organic electroluminescent device according to claim 7, wherein: The substituent represented by Formula 2 is represented by any one of Formulas 6-1 to 6-4: Formula 6-1 Formula 6-2 Formula 6-3 Formula 6-4 Among them, in Formula 6-1 to Formula 6-4, R 41 To R 46 are each independently 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 60 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group of 2 to 60 carbon atoms for forming a ring, and R 41 To R 46 Any one of which is optionally combined with an adjacent group to form a ring, n3 and n4 are each independently an integer from 0 to 3, n5 to n8 are each independently an integer from 0 to 4, m1 and m2 are independently 0 or 1, and At least one of m1 and m2 is 1.

9. The organic electroluminescent device according to claim 1, wherein: The substituent represented by Formula 2 is represented by Formula 7-1 or Formula 7-2: Formula 7-1 Formula 7-2 Among them, in formula 7-1 and formula 7-2, R4 and R5 are the same as defined in Formula 2.

10. The organic electroluminescent device according to claim 1, wherein: X1 and X2 are independently NR1 or O, and R1 is a substituted or unsubstituted phenyl group.

11. The organic electroluminescent device according to claim 1, wherein: The second compound is at least one compound selected from the group consisting of: Compound Group 1

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