Organic electroluminescent device

Abstract

An organic electroluminescent device of an embodiment is provided. The organic electroluminescent device 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, wherein at least one among the organic layers includes a fused polycyclic compound represented by the following Formula 1, thereby exhibiting improved emission efficiency. [Formula 1] wherein, X, Y, R 11 to R 21 are the same as defined in the specification.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2019-0065164, filed on June 3, 2019, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates here to an organic electroluminescent device and a fused polycyclic compound for use in an organic electroluminescent device, and more particularly, to a fused polycyclic compound for use as a light-emitting material and an organic electroluminescent device including the same. BACKGROUND

[0003] Recently, development of an organic electroluminescent display device as an image display device is actively being conducted. Unlike a liquid crystal display device, an organic electroluminescent display device is a so-called self-luminescent display device in which holes and electrons injected from a first electrode and a second electrode recombine in an emission layer, and a light-emitting material (including an organic compound) in the emission layer emits light to implement display (e.g., an image).

[0004] In applying an organic electroluminescent device to a display device, there is a need to reduce a driving voltage, and there is a need to increase emission efficiency and life (e.g., lifespan) of the organic electroluminescent device, and development of a material required for the organic electroluminescent device to stably meet the requirements is continuously being conducted.

[0005] In particular, recently, in order to implement an organic electroluminescent device having high efficiency, technology related to phosphorescent emission (which utilizes an energy level of a triplet state) or delayed fluorescent emission (which utilizes a phenomenon (triplet-triplet annihilation, TTA) in which a singlet state exciton is generated by collision of triplet excitons) is being developed, and a material utilizing a thermally activated delayed fluorescence (TADF) of a delayed fluorescent phenomenon is being developed. SUMMARY

[0006] An aspect of an embodiment according to the present disclosure is to provide an organic electroluminescent device having improved emission efficiency.

[0007] Another aspect of an embodiment according to the present disclosure is to provide a fused polycyclic compound capable of improving emission efficiency of an organic electroluminescent device.

[0008] According to embodiments of inventive concepts, an organic electroluminescent device includes a first electrode; a second electrode opposite to the first electrode; and a plurality of organic layers between the first electrode and the second electrode, wherein 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 include a composite of two 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, a mixture of two 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, or an oxide of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn, and Zn, wherein at least one of the plurality of organic layers includes a fused polycyclic compound represented by the following Formula 1:

[0009] Formula 1

[0010]

[0011] In Formula 1, one selected from X and Y is BR a or P(=O)R b , and the other selected from X and Y is SiR c R d , and R a to R d 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 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms, and any one of R a to R d may (optionally) be combined with an adjacent group to form a ring. R 11 to R 21 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a boron group, a phosphine oxide group, a cyano group, a substituted or unsubstituted amine group, 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 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms, and any one of R 11 to R 21Any one of R1to R4in the above formula 1 can be (optionally) combined with an adjacent group to form a ring.

[0012] In an embodiment, the plurality of organic layers can 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, and the emission layer can include the fused polycyclic compound represented by formula 1.

[0013] In an embodiment, the emission layer can emit delayed fluorescence.

[0014] In an embodiment, the emission layer can be a delayed fluorescence emission layer including a host and a dopant, and the dopant can include the fused polycyclic compound represented by formula 1.

[0015] In an embodiment, the emission layer can 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, and the first dopant can include the fused polycyclic compound represented by formula 1.

[0016] In an embodiment, the first dopant can be a delayed fluorescence dopant, and the second dopant can be a fluorescent dopant.

[0017] In an embodiment, the fused polycyclic compound represented by formula 1 can be represented by any one of the following formulae 1-1 to 1-3:

[0018] Formula 1-1

[0019]

[0020] Formula 1-2

[0021]

[0022] Formula 1-3

[0023]

[0024] In formulae 1-1 to 1-3, R1to R4 11 , R 21 , R c , and R d are the same as defined in connection with formula 1, respectively, and X1, X 11 , X 12 , and X 13 are each independently B or P(=O). R n , and R meach independently is 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 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms, and R n and R m each can (optionally) combine with an adjacent group to form a ring, n is an integer of 0 to 5, and m is an integer of 0 to 4. R aa and R bb each independently is 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 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms, and R aa and R bb each can (optionally) combine with an adjacent group to form a ring, and Ar is 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 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms.

[0025] In an embodiment, X1in Formula 1-1 can be P(=O), and n can be 0.

[0026] In an embodiment, X 11 and X 12 in Formula 1-2 can be the same.

[0027] In an embodiment, in Formula 1-2, in the case where X 11 and X 12 are each B, R aa and R bb each can independently be a substituted or unsubstituted phenyl group, in the case where X 11 and X 12 are each P(=O), R aa and R bb each can independently be an unsubstituted phenyl group.

[0028] In an embodiment, R c and R d each can independently be an unsubstituted phenyl group.

[0029] According to embodiments of the inventive concept, there is provided a fused polycyclic compound represented by the above Formula 1. BRIEF DESCRIPTION OF DRAWINGS

[0030] 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 drawings illustrate exemplary embodiments of the inventive concept and, together with the description, serve to explain the principles of the inventive concept. In the drawings:

[0031] Figure 1 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the inventive concept;

[0032] Figure 2 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the inventive concept;

[0033] Figure 3 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the inventive concept; and

[0034] Figure 4 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the inventive concept. DETAILED DESCRIPTION

[0035] The inventive concept can have various suitable modifications and can be implemented in different forms, and exemplary embodiments will be described in more detail with reference to the drawings. However, the inventive concept can be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, all modifications, equivalents, and alternatives falling within the spirit and technical scope of the inventive concept should be included in the inventive concept.

[0036] It will be understood that when an element is referred to as being "on" another element, "connected to" another element, or "coupled to" another element, it can be directly on, directly connected to, or directly coupled to the other element, or intervening elements can be present.

[0037] The same reference numerals will be used throughout the drawings and writing to refer to the same or like elements. In addition, in the drawings, the thickness, proportions, and dimensions of constituent elements are exaggerated for the sake of efficiency and clarity in explanation of the technical content.

[0038] The term "and / or" includes one or more combinations of the associated elements.

[0039] It will be understood that, although the terms first, second, etc. can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element could be termed a second element without departing from the teachings of the present disclosure. Similarly, a second element could be termed a first element without departing from the teachings of the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms "a," "an," and "the" are intended to include the plural forms as well.

[0040] Also, the terms "below", "under", "above" and "on" 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.

[0041] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0042] It will be further understood that the terms "comprises" and / or "comprising", or "includes" and / or "including" when used in this specification, specify the presence of stated features, numbers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.

[0043] Hereinafter, an organic electroluminescent device according to an embodiment of the inventive concept will be explained in more detail with reference to the accompanying drawings.

[0044] Figures 1 to 4 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an exemplary embodiment of the inventive concept. Referring to Figures 1 to 4 In the organic electroluminescent device 10 according to the embodiment, a first electrode EL1 and a second electrode EL2 are disposed opposite to each other, and between the first electrode EL1 and the second electrode EL2, a plurality of organic layers can be disposed. The plurality of organic layers can 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 can include (e.g., in the order of the recitation) the first electrode EL1, the hole transport region HTR, the emission layer EML, the electron transport region ETR, and the second electrode EL2, which are stacked on each other. On the second electrode EL2, a cap layer CPL (see Figure 4 ) can be further disposed.

[0045] The organic electroluminescent device 10 of the embodiment can include the fused polycyclic compound of the embodiment to be explained later in more detail in at least one organic layer among a plurality of organic layers disposed between the first electrode EL1 and the second electrode EL2. For example, the organic electroluminescent device 10 of the embodiment can include the fused polycyclic compound of the embodiment to be explained later in more detail in an 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 embodiment can include the fused polycyclic compound of the embodiment to be explained later in more detail in at least one organic layer among a plurality of organic layers disposed between the first electrode EL1 and the second electrode EL2, except for the emission layer EML, including in at least one of a hole transport region HTR and an electron transport region ETR, or in a cap layer CPL disposed on the second electrode EL2.

[0046] Meanwhile, when compared with Figure 1 Figure 2 A cross-sectional view of the organic electroluminescent device 10 of the embodiment is illustrated in which the hole transport region HTR includes a hole injection layer HIL and a hole transport layer HTL and the electron transport region ETR includes an electron injection layer EIL and an electron transport layer ETL. In addition, when compared with Figure 1 Figure 3 A cross-sectional view of the organic electroluminescent device 10 of the embodiment is illustrated in which the hole transport region HTR includes a hole injection layer HIL, a hole transport layer HTL, and an electron blocking layer EBL and the electron transport region ETR includes an electron injection layer EIL, an electron transport layer ETL, and a hole blocking layer HBL. When compared with Figure 1 Figure 4 A cross-sectional view of the organic electroluminescent device 10 of the embodiment is illustrated which includes a cap layer CPL disposed on the second electrode EL2.

[0047] Hereinafter, in explaining the organic electroluminescent device 10 of the embodiment, the emission layer EML is explained as including the fused polycyclic compound according to the embodiment to be explained later in more detail, but the embodiments of the inventive concept are not limited thereto. The fused polycyclic compound according to the embodiment to be explained later in more detail can be included in the hole transport region HTR, the electron transport region ETR, or the cap layer CPL.

[0048] ​​​The first electrode EL1 is conductive. For example, the first electrode EL1 may 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 may 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. The first electrode EL1 can be a composite of two or more of the following: a mixture 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 Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn, and Zn. The first electrode EL1 can be formed using a metal alloy and / or a conductive compound. The first electrode EL1 can be an anode. The first electrode EL1 can be a pixel electrode. The first electrode EL1 can be a transmission electrode, a transmission-reflection electrode, or a reflection electrode. If the first electrode EL1 is a transmission electrode, it can be formed using a transparent metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO). If the first electrode EL1 is a transmissive / reflective electrode or a reflective electrode, then 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, their composites, or mixtures thereof (e.g., a mixture of Ag and Mg). Furthermore, the first electrode EL1 may have a structure comprising multiple layers, including a reflective or transmissive layer formed using the aforementioned 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 approximately For example, about to approximately

[0049] A hole transport region (HTR) is disposed on the first electrode EL1. The HTR may include a hole injection layer (HIL), a hole transport layer (HTL), a hole buffer layer, and / or an electron blocking layer (EBL). The thickness of the HTR can be approximately [missing information]. to approximately

[0050] The hole transport region HTR can have a single layer formed with a single material, a single layer formed with a plurality of different materials, or a multi-layer structure including a plurality of layers formed with a plurality of different materials.

[0051] For example, the hole transport region HTR can have a single layer structure of a hole injection layer HIL or a hole transport layer HTL, or can have a single layer structure formed with a hole injection material and a hole transport material. Alternatively, the hole transport region HTR can have a single layer structure formed with a plurality of different materials, or can 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 stacked from the first electrode EL1, but the present disclosure is not limited thereto.

[0052] The hole transport region HTR can be formed with various 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.

[0053] The hole injection layer HIL can include, for example, a phthalocyanine compound such as copper phthalocyanine, (N 1 ,N 1 '-([1,1'-biphenyl]-4,4'-diyl)bis(N 1 -phenyl-N 4 ,N 4 -di-m-tolyl-1,4-diamine)) (DNTPD), 4,4',4"-[tris(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4',4"-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tris{N-(2-naphthyl)-N-phenylamino}triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), polyaniline / camphor sulfonic acid (PANI / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), N,N'-bis(naphthalen-1-yl)-N,N'-diphenyl-benzidine (NPB), N,N'-bis(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (NPD), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyl diphenyl iodonium [tetrakis(pentafluorophenyl)borate], and / or dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexanitrile (HAT-CN).

[0054] Hole transport layers (HTLs) can include, for example, carbazole derivatives (such as N-phenylcarbazole, polyvinylcarbazole), fluorene derivatives, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD), triphenylamine derivatives (such as 4,4',4”-tris(N-carbazolyl)triphenylamine (TCTA)), and N,N'-bis(1-naphthyl)-N,N'-diphenyl Examples of such products include 4,4'-cyclohexyl-bis[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 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi).

[0055] The thickness of the hole transport region HTR can be approximately to approximately For example, about to approximately The thickness of the hole injection layer (HIL) can be, for example, approximately to approximately The thickness of the hole transport layer (HTL) can be approximately to approximately For example, the thickness of the electron blocking layer (EBL) can be approximately to approximately If the thicknesses of the hole transport region (HTR), hole injection layer (HIL), hole transport layer (HTL), and electron blocking layer (EBL) meet the above ranges, satisfactory hole transport performance can be achieved without significantly increasing the driving voltage.

[0056] In addition to the materials described above, the hole transport region (HTR) may also 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-doper. The p-doper may be one of quinone derivatives, metal oxides, and cyano-containing compounds, but this disclosure is not limited thereto. For example, non-limiting examples of p-dopers may include quinone derivatives (such as tetracyanoquinone dimethyl (TCNQ) and / or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinone dimethyl (F4-TCNQ)) and / or metal oxides (such as tungsten oxide and / or molybdenum oxide), but this disclosure is not limited thereto.

[0057] As described above, the hole transport region HTR can further include a hole buffer layer and / or an electron blocking layer EBL in addition to the hole injection layer HIL and the hole transport layer HTL. The hole buffer layer can compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer EML to improve light emission efficiency. Materials that can be included in the hole transport region HTR can be used as materials included in the hole buffer layer. The electron blocking layer EBL is a layer that functions to prevent or substantially prevent injection of electrons from the electron transport region ETR to the hole transport region HTR.

[0058] The emission layer EML is disposed on the hole transport region HTR. The emission layer EML can have a thickness of, for example, about 1 nm to about 10 nm, about 1 nm to about 8 nm, about 1 nm to about 6 nm, about 1 nm to about 4 nm, about 1 nm to about 2 nm, about 2 nm to about 10 nm, about 2 nm to about 8 nm, about 2 nm to about 6 nm, about 2 nm to about 4 nm, about 4 nm to about 10 nm, about 4 nm to about 8 nm, about 4 nm to about 6 nm, about 6 nm to about 10 nm, about 6 nm to about 8 nm, about 8 nm to about 10 nm, or about 10 nm. about 10 nm, about 4 nm to about 10 nm, about 4 nm to about 8 nm, about 4 nm to about 6 nm, about 6 nm to about 10 nm, about 6 nm to about 8 nm, about 8 nm to about 10 nm, or about 10 nm. The emission layer EML can have a single layer formed with a single material, a single layer formed with a plurality of different materials, or a multi-layer structure including a plurality of layers formed with a plurality of different materials.

[0059] In the organic electroluminescent device 10 of the embodiment, the emission layer EML can include the fused polycyclic compound of the embodiment.

[0060] In the specification, the term "substituted or unsubstituted" refers to a group that is either unsubstituted or substituted with at least one substituent selected from the group consisting of a deuterium atom, a halogen atom, a cyano group, a nitro group, an amino group, a silyl group, an oxy group (or "oxyl group"), a thiol 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 hydrocarbyl group, an aryl group, and a heterocyclic group. In addition, each of the exemplary substituents 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.

[0061] In the specification, the term "forms a ring via bonding with an adjacent group" can refer to forming a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocyclic ring via bonding with an adjacent group. The hydrocarbon ring includes an aliphatic hydrocarbon ring and an aromatic hydrocarbon ring. The heterocyclic ring includes an aliphatic heterocyclic ring and an aromatic heterocyclic ring. The ring formed by bonding with an adjacent group can be a monocyclic ring or a polycyclic ring. In addition, the ring formed by bonding with an adjacent group can be combined with another ring to form a spiro structure.

[0062] ​​In the specification, the term "adjacent groups" can refer to a substituent substituted for an atom directly bonded to an atom substituted with a corresponding substituent, another substituent substituted for an atom substituted with a corresponding substituent, or a substituent spatially located closest to a corresponding substituent. For example, in 1,2-dimethylbenzene, the two methyl groups can be interpreted as "adjacent groups" to each other, and in 1,1-diethylcyclopentane, the two ethyl groups can be interpreted as "adjacent groups" to each other.

[0063] In the specification, a halogen atom can be a fluorine atom, a chlorine atom, a bromine atom, and / or an iodine atom.

[0064] In the specification, an alkyl group can be a linear alkyl group, a branched alkyl group, or a cyclic alkyl group. The number of carbons of an alkyl group can be 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of an alkyl group can include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, an iso-butyl group, a 2-ethylbutyl group, a 3,3-dimethylbutyl group, an n-pentyl group, an iso-pentyl group, a neopentyl group, a t-pentyl group, a cyclopentyl group, a 1-methylpentyl group, a 3-methylpentyl group, a 2-ethylpentyl group, a 4-methyl-2-pentyl group, an n-hexyl group, a 1-methylhexyl group, a 2-ethylhexyl group, a 2-butylhexyl group, a cyclohexyl group, a 4-methylcyclohexyl group, a 4-t-butylcyclohexyl group, an n-heptyl group, a 1-methylheptyl group, a 2,2-dimethylheptyl group, a 2-ethylheptyl group, a 2-butylheptyl group, an n-octyl group, a t-octyl group, a 2-ethyloctyl group, a 2-butyl-octyl group, a 2-hexyloctyl group, a 3,7-dimethyloctyl group, a cyclooctyl group, an n-nonyl group, an n-decyl group, an adamantyl group, a 2-ethyldecyl group, a 2-butyldecyl group, a 2-hexyldecyl group, a 2-octyldecyl group, an n-undecyl group, an n-dodecyl group, a 2-ethyldodecyl group, a 2-butyl-dodecyl group, a 2-hexyl-dodecyl group, a 2-octyl-dodecyl group, an n-tridecyl group, an n-tetradecyl group, an n-pentadecyl group, an n-hexadecyl group, a 2-ethylhexadecyl group, a 2-butylhexadecyl group, a 2-hexylhexadecyl group, a 2-octylhexadecyl group, an n-heptadecyl group, an n-octadecyl group, an n-nonadecyl group, an n-eicosyl group, a 2-ethyleicosyl group, a 2-butyleicosyl group, a 2-hexyleicosyl group, a 2-octyleicosyl group, an n-heneicosyl group, an n-docosyl group, an n-tricosyl group, an n-tetracosyl group, an n-pentacosyl group, an n-hexacosyl group, an n-heptacosyl group, an n-octacosyl group, an n-nonacosyl group, an n-triacontyl group, and the like, but the present disclosure is not limited thereto.

[0065] In the specification, a hydrocarbon ring includes an aliphatic hydrocarbon ring and an aromatic hydrocarbon ring. A heterocyclic ring includes an aliphatic heterocyclic ring and an aromatic heterocyclic ring. A hydrocarbon ring and a heterocyclic ring can be a single ring or a multiple ring.

[0066] In the specification, a hydrocarbon ring can be an optional functional group or a substituent derived from an aliphatic hydrocarbon ring or an optional functional group or a substituent derived from an aromatic hydrocarbon ring. The number of carbons forming a ring of a hydrocarbon ring can be 5 to 60.

[0067] In the specification, the heterocyclic group can be an optional functional group or substituent derived from a heterocycle that includes at least one heteroatom as a cyclizing element. The number of carbon atoms in the forming ring of the heterocyclic group can be from 2 to 60.

[0068] In this specification, aryl refers to an optional functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group can be monocyclic or polycyclic. The number of carbon atoms forming the ring in the aryl group can be 6 to 30, 6 to 20, or 6 to 15. Examples of aryl groups include phenyl, naphthyl, fluorenyl, anthracene, phenanthryl, biphenyl, terphenyl, tetraphenyl, pentaphenyl, hexaphenyl, benzo[9,10]phenanthryl, pyrene, benzofluoranthracene, etc. This disclosure is based on, but not limited thereto.

[0069] In this specification, the fluorene group may be substituted, and two substituents may combine with each other to form a spirostructure. Examples of substituted fluorene groups are given below. However, embodiments of the inventive concept are not limited thereto.

[0070]

[0071] In the specification, a heteroaryl group can be a heteroaryl group comprising one or more heteroatoms selected from B, O, N, P, Si, and S. If a heteroaryl group comprises two or more heteroatoms, the two or more heteroatoms can be the same or different. A heteroaryl group can be a monocyclic heteroaryl group or a polycyclic heteroaryl group. The ring forming the heteroaryl group can have 2 to 30, 2 to 20, or 2 to 10 carbon atoms. Examples of heteroaryl groups may include thienyl, furanyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridineyl, pyridazinyl, quinolinyl, quinazolinyl, quinoxazinyl, phenothiazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolinyl, indolyl, carbazole, N-arylcarbazole, N-heteroarylcarbazole, N-alkylcarbazole, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazole, benzothiazolyl, benzothiaphenyl, dibenzothiaphenyl, thiaphenothiaphenyl, benzofuranyl, phenanthrolyl, isoxazolyl, thiadiazolyl, phenothiazinyl, dibenzothiaryl, dibenzofuranyl, etc., but this disclosure is not limited thereto.

[0072] In the specification, silane includes alkylsilane and arylsilane. Examples of silane may include trimethylsilane, triethylsilane, tert-butyldimethylsilane, propyldimethylsilane, triphenylsilane, diphenylsilane, phenylsilane, etc. However, embodiments of the inventive concept are not limited thereto.

[0073] In the specification, a boron group includes an alkyl boron group and an aryl boron group. Examples of the boron group include a trimethyl boron group, a triethyl boron group, a tert-butyl dimethyl boron group, a triphenyl boron group, a diphenyl boron group, a phenyl boron group, and the like, but the present disclosure is not limited thereto.

[0074] In the specification, the number of carbons of an amine group (or amino group) is not particularly limited, and can be 1 to 30. The amine group can include an alkyl amine group and an aryl amine group. Examples of the amine group include a methyl amine group, a dimethyl amine group, a phenyl amine group, a naphthyl amine group, a 9-methyl-anthryl amine group, a triphenyl amine group, and the like, but the present disclosure is not limited thereto.

[0075] In the specification, a hydrocarbon ring refers to an optional functional group or substituent derived from an aliphatic hydrocarbon ring. The hydrocarbon ring can be a saturated hydrocarbon ring of 5 to 20 carbon atoms forming a ring.

[0076] In the specification, a heterocyclic group can include one or more selected 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 can be the same or different. The heterocyclic group can be a monocyclic heterocyclic group or a polycyclic heterocyclic group, and has the concept including (for example, can include) a heteroaryl group. The number of carbons forming the ring of the heterocyclic group can be 2 to 30, 2 to 20, or 2 to 10.

[0077] The fused polycyclic compound of the embodiment can be represented by the following Formula 1:

[0078] Formula 1

[0079]

[0080] In Formula 1, one selected from X and Y is BR a or P(=O)R b , and the other selected from X and Y is SiR c R d . For example, in the fused polycyclic compound represented by Formula 1 of the embodiment, either one selected from X and Y can be BR a , and the other can be SiR c R d , or either one selected from X and Y can be P(=O)R b , and the other can be SiR c R d . That is, the fused polycyclic compound of the embodiment can necessarily include Si as a heteroatom.

[0081] In Formula 1, R a to R dEach of the following can be independently a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group with 1 to 20 carbon atoms (substituted or unsubstituted), an aryl group with 6 to 60 carbon atoms forming a ring (substituted or unsubstituted), or a heteroaryl group with 2 to 60 carbon atoms forming a ring (substituted or unsubstituted), and R a To R d Any one of them can (optionally) combine with an adjacent group to form a ring.

[0082] For example, in Equation 1, R a and R b Each of these can be an aryl group consisting of 6 to 60 substituted or unsubstituted carbon atoms forming a ring. In one embodiment, R a and R b Each of these can be an aryl group consisting of 6 to 60 cyclic carbon atoms substituted with an alkyl or aryl group, or an unsubstituted aryl group consisting of 6 to 60 cyclic carbon atoms. In Formula 1, R a and R b Each of them can be a substituted or unsubstituted phenyl group.

[0083] In Equation 1, R c and R d They can be the same. For example, in Equation 1, R c and R d Both can be independently substituted or unsubstituted phenyl groups. In one embodiment, R c and R d All of them can be unsubstituted phenyl groups.

[0084] Additionally, in Equation 1, R 11 To R 21 Each of these groups can independently be a hydrogen atom, a deuterium atom, a halogen atom, a boron group, a phosphonium oxide group, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted silyl group, an substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 60 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group with 2 to 60 cyclic carbon atoms, and R 11 To R 21 Any one of them can (optionally) combine with an adjacent group to form a ring (i.e., R). 11 To R 21 Each group can independently and optionally combine with adjacent groups to form a ring.

[0085] For example, in Equation 1, R 11 To R 21 Each group can independently be a hydrogen atom, an arylamine group, an aryl group with 6 to 30 substituted or unsubstituted carbon atoms forming a ring, or a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms forming a ring, and R 11 To R 21Any one of the above can be (optionally) combined with an adjacent group to form a hydrocarbon ring or a heterocyclic ring.

[0086] In Formula 1, R 11 to R 21 may be an electron donor substituent represented by an arylamine group or the like, or an electron acceptor substituent represented by a heteroaryl group including N (nitrogen atom) as a ring-forming element, an aryl group substituted with an aryl group, or an unsubstituted aryl group.

[0087] When compared with the DABNA series polycyclic compounds of the related art including N and B as heteroatoms forming a ring, the fused polycyclic compounds of the embodiments must include Si as a ring-forming heteroatom forming a corresponding fused ring in the core, and can exhibit bulkiness and improved rigidity. In addition, the fused polycyclic compounds of the embodiments exhibit multiple resonance through the plurality of aromatic rings forming the fused ring, and can separate (e.g., easily separate) the HOMO state and the LUMO state in one molecule, and thus can be suitably used as a delayed fluorescence emission material. In addition, when compared with the DABNA series polycyclic compounds of the related art, the fused polycyclic compounds of the embodiments include Si as a ring-forming heteroatom and exhibit increased rigidity, and thus can reduce the τ value (delayed emission time) and exhibit an increased rate of reverse intersystem crossing (RISC) and an improved lifetime effect (e.g., improved lifetime). In addition, because the fused polycyclic compounds of the embodiments have a high lowest triplet excited energy level (T1 level), when used as a delayed fluorescence emission material, the emission efficiency of the organic electroluminescent device can be further improved.

[0088] The fused polycyclic compound represented by Formula 1 can be represented by any one of the following Formulae 1-1 to 1-3:

[0089] Formula 1-1

[0090]

[0091] Formula 1-2

[0092]

[0093] Formula 1-3

[0094]

[0095] In Formula 1-1, X1may be B or P(=O). In Formula 1-1, R nmay be 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 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms, and can (optionally) be combined with an adjacent group to form a ring (i.e., R n may be optionally combined with an adjacent group to form a ring).

[0096] n can be an integer of 0 to 5. Further, in Formula 1-1, when n is 0, the phenyl group combined with X1may be an unsubstituted phenyl group. In addition, when n is 5 and all R n are hydrogen atoms, the phenyl group combined with X1may be an unsubstituted phenyl group. In Formula 1-1, when n is an integer of 2 or more, a plurality of R n may be the same, or at least one of a plurality of R n may be different.

[0097] In Formula 1-1, when X1is B, the phenyl group combined with X1may be a substituted or unsubstituted phenyl group. For example, R n may be a hydrogen atom or a methyl group. In addition, in Formula 1-1, when X1is P(=O), the phenyl group combined with X1may be an unsubstituted phenyl group. For example, in Formula 1-1, when X1is P(=O), n can be 0.

[0098] In Formula 1-2, X 11 and X 12 may each independently be B or P(=O). For example, X 11 and X 12 may be the same. In one embodiment, both X 11 and X 12 may be B, or both X 11 and X 12 may be P(=O).

[0099] In Formula 1-2, R aa and R bb 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 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms, and any one of R aa and R bb may (optionally) be combined with an adjacent group to form a ring (i.e., R aa and R bb may each independently be optionally combined with an adjacent group to form a ring).

[0100] For example, R aa and Rbb Each group can be an aryl group consisting of 6 to 30 substituted or unsubstituted carbon atoms forming a ring. In one embodiment, R aa and R bb They can all be independently substituted or unsubstituted phenyl groups. In formulas 1-2, when X 11 and X 12 When both are B, R aa and R bb They can all be independently substituted or unsubstituted phenyl groups, when X 11 and X 12 When both are P (=O), R aa and R bb Each can be an unsubstituted phenyl group independently.

[0101] In equations 1-3, X 13 It can be B or P (=O). In Equation 1-3, R m It can be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 60 carbon atoms forming a ring, or a substituted or unsubstituted heteroaryl group with 2 to 60 carbon atoms forming a ring, and can (optionally) combine with adjacent groups to form a ring (i.e., R). m It can combine with adjacent groups to form a ring.

[0102] m can be an integer from 0 to 4. In equations 1-3, when m is an integer of 2 or greater, multiple R... m They can be the same, or multiple Rs. m At least one of them can be different.

[0103] For example, in equation 1-3, R m It can be a substituted or unsubstituted aryl amino group, a substituted or unsubstituted aryl group with 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroaryl group with 2 to 30 ring-forming carbon atoms, and can (optionally) combine with adjacent groups to form a substituted or unsubstituted fluorenyl group.

[0104] In Formulas 1-3, Ar can be a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group with 1 to 20 carbon atoms (substituted or unsubstituted), an aryl group with 6 to 60 carbon atoms forming a ring (substituted or unsubstituted), or a heteroaryl group with 2 to 60 carbon atoms forming a ring (substituted or unsubstituted). For example, Ar can be an aryl group with 6 to 30 carbon atoms forming a ring (substituted or unsubstituted).

[0105] Furthermore, in Equations 1-1 to 1-3, the same interpretations as in Equation 1 can be applied to R. 11 To R 21 R c and Rd .

[0106] The fused polycyclic compound of the embodiments can be any one selected from the group of compounds 1 below. The organic electroluminescent device 10 of the embodiments can include at least one fused polycyclic compound selected from the compounds represented in the group of compounds 1 in the emission layer EML.

[0107] Group of Compounds 1

[0108]

[0109]

[0110]

[0111] The fused polycyclic compound represented by Formula 1 of the embodiments can be a thermally activated delayed fluorescence emitting material. In addition, the fused polycyclic compound represented by Formula 1 of the embodiments can be a thermally activated delayed fluorescence dopant having a difference (ΔE ST ) between the lowest triplet excited energy level (T1 energy level) and the lowest singlet excited energy level (S1 energy level) of about 0.2 eV or less (for example, about 0.1 eV or less). For example, the ΔE ST of the fused polycyclic compound represented by Formula 1 of the embodiments can be about 0.01 eV or less.

[0112] The fused polycyclic compound represented by Formula 1 of the embodiments can be a light emitting material having a light emission 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 embodiments can be a blue thermally activated delayed fluorescence (TADF) dopant. However, embodiments of the inventive concept are not limited thereto, and in the case of utilizing the fused polycyclic compound of the embodiments as a light emitting material, the fused polycyclic compound can 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.

[0113] In the organic electroluminescent device 10 of the embodiments, the emission layer EML can emit delayed fluorescence. For example, the emission layer EML can emit thermally activated delayed fluorescence (TADF).

[0114] In addition, the organic electroluminescent device 10 can emit blue light. For example, the emission layer EML of the organic electroluminescent device 10 of the embodiments can emit blue light in a wavelength region of about 490 nm or more. However, embodiments of the inventive concept are not limited thereto, and the emission layer EML can emit green light or red light.

[0115] Further, in one embodiment, the organic electroluminescent device 10 of the embodiment can include a plurality of emission layers. The plurality of emission layers can be stacked and disposed with each other. For example, the organic electroluminescent device 10 including the plurality of emission layers can emit white light. The organic electroluminescent device 10 including the plurality of emission layers can be an organic electroluminescent device having a tandem structure. When the organic electroluminescent device 10 includes the plurality of emission layers, at least one emission layer EML can include the fused polycyclic compound of the embodiment.

[0116] In the embodiment, the emission layer EML includes a host and a dopant, and can include the fused polycyclic compound of the embodiment as the dopant. For example, in the organic electroluminescent device 10 of the embodiment, the emission layer EML can include a host for emitting delayed fluorescence and a dopant for emitting delayed fluorescence, and can include the fused polycyclic compound as the dopant for emitting delayed fluorescence. The emission layer EML can include at least one selected from the fused polycyclic compounds represented in Compound Group 1 as a thermally activated delayed fluorescence dopant.

[0117] In the embodiment, the emission layer EML can be a delayed fluorescence emission layer, and the emission layer EML can include a suitable (e.g., known) host material and the above-described fused polycyclic compound. For example, in the embodiment, the fused polycyclic compound can be used as a TADF dopant.

[0118] Further, in embodiments, the emission layer EML can include a suitable (e.g., known) host material. For example, in embodiments, the emission layer EML can include tris(8-hydroxyquinoline)aluminum (Alq3), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), poly(N-vinylcarbazole) (PVK), 9,10-di(naphthalen-2-yl)anthracene (ADN), 4,4',4"-tris(carbazol-9-yl)triphenylamine (TCTA), 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBi), 3-tert-butyl-9,10-di(naphthalen-2-yl)anthracene (TBADN), distyrylarylidene (DSA), 4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl (CDBP), 2-methyl-9,10-di(naphthalen-2-yl)anthracene (MADN), bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO3), octaphenylcyclotetrasiloxane (DPSiO4), 2,8-bis(diphenylphosphoryl)dibenzo[b,d]furan (PPF), 3,3'-bis(N-carbazolyl)-1,1'-biphenyl (mCBP), 1,3-bis(N-carbazolyl)benzene (mCP), or the like as a host material. However, embodiments of the inventive concept are not limited thereto. Any suitable (e.g., known) host material other than the proposed host materials can be included to emit delayed fluorescence.

[0119] Further, in embodiments, the emission layer EML can include a suitable (e.g., known) host material. For example, in embodiments, the emission layer EML can include tris(8-hydroxyquinoline)aluminum (Alq3), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), poly(N-vinylcarbazole) (PVK), 9,10-di(naphthalen-2-yl)anthracene (ADN), 4,4',4"-tris(carbazol-9-yl)triphenylamine (TCTA), 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBi), 3-tert-butyl-9,10-di(naphthalen-2-yl)anthracene (TBADN), distyrylarylidene (DSA), 4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl (CDBP), 2-methyl-9,10-di(naphthalen-2-yl)anthracene (MADN), bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO3), octaphenylcyclotetrasiloxane (DPSiO4), 2,8-bis(diphenylphosphoryl)dibenzo[b,d]furan (PPF), 3,3'-bis(N-carbazolyl)-1,1'-biphenyl (mCBP), 1,3-bis(N-carbazolyl)benzene (mCP), or the like as a host material. However, embodiments of the inventive concept are not limited thereto. Any suitable (e.g., known) host material other than the proposed host materials can be included to emit delayed fluorescence.

[0120] In addition, in an embodiment, the emission layer EML can include two kinds of dopant materials having different lowest triplet excitation energy levels (T1 energy levels) from each other. In the organic electroluminescent device 10 of an embodiment, the emission layer EML can 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 an embodiment, the emission layer EML can include the above-described fused polycyclic compound as the first dopant.

[0121] In the organic electroluminescent device 10 of an embodiment including a host, a first dopant, and a second dopant in the emission layer EML, the first dopant can be a delayed fluorescence dopant, and the second dopant can be a fluorescent dopant. In addition, in the organic electroluminescent device 10 of an embodiment, the fused polycyclic compound represented by Formula 1 can function as an auxiliary dopant.

[0122] For example, when the emission layer EML of the organic electroluminescent device 10 of an embodiment includes a plurality of dopants, the emission layer EML can include the fused polycyclic compound of an embodiment as a first dopant and the above-described suitable (e.g., known) dopant material as a second dopant. For example, when the emission layer EML emits blue light, the emission layer EML can further include any one selected from the group consisting of spiro-DPVBi, spiro-6P, distyryl-benzene (DSB), distyryl-arylene (DSA), polyfluorene (PFO)-based polymers, and poly(p-phenylenevinylene)-based polymers as the second dopant. In addition, the second dopant can use metal complexes and / or organometallic complexes such as (4,6-F2ppy)2Irpic, perylene and derivatives thereof, etc. Meanwhile, in the organic electroluminescent device 10 of an embodiment including the fused polycyclic compound of an embodiment as a first dopant of the emission layer EML, the emission layer EML can emit green light or red light, in which case the second dopant material used can be the above-described suitable (e.g., known) dopant, a suitable (e.g., known) green fluorescent dopant, or a suitable (e.g., known) red fluorescent dopant.

[0123] In the organic electroluminescent device 10 of an embodiment, the emission layer EML can be a phosphorescent emission layer. For example, the fused polycyclic compound according to an embodiment can be included in the emission layer EML as a phosphorescent host material.

[0124] In the organic electroluminescent device 10 of an embodiment, as Figures 1 to 3As shown, the electron transport region (ETR) is disposed on the emitter layer (EML). The electron transport region (ETR) may include a hole blocking layer (HBL), an electron transport layer (ETL), and / or an electron injection layer (EIL). However, embodiments of the inventive concept are not limited thereto.

[0125] The electronic transmission region (ETR) can have a single layer made of a single material, a single layer made of multiple different materials, or a multi-layer structure with multiple layers made of multiple different materials.

[0126] For example, the electron transport region (ETR) can 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. Furthermore, the ETR can have a single-layer structure comprising a variety of different materials, or 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 the emitter layer (EML), but this disclosure is not limited thereto. The thickness of the ETR can be, for example, approximately... to approximately

[0127] Electron transport regions (ETRs) can be formed using a variety of suitable methods such as vacuum deposition, spin coating, casting, Langmuir-Blodget (LB) methods, inkjet printing, laser printing, and / or laser-induced thermal imaging (LITI).

[0128] If the electron transport region (ETR) includes an electron transport layer (ETL), then the ETR may include anthracene compounds. The ETR may include, for example, tris(8-hydroxyquinoline)aluminum (Alq3), 1,3,5-tris[(3-pyridyl)-benzyl-3-yl]benzene, 2,4,6-tris(3'-(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-benzimidazol-2-yl)benzene (TPBi), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2, 4-Triazole (TAZ), 4-(naphthyl-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), bis(benzoquinoline-10-hydroxy)beryllium (Bebq2), 9,10-bis(naphthyl-2-yl)anthracene (ADN), diphenyl(4-(triphenylsilyl)phenyl)phosphine oxide (TSPO1), bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), or mixtures thereof, but this disclosure is not limited thereto. The thickness of the electron transport layer ETL can be approximately to approximately And it can be, for example, about to approximately When the thickness of the electron transport layer (ETL) meets the above range, satisfactory electron transport performance can be obtained without significantly increasing the driving voltage.

[0129] If the electron transport region (ETR) includes an electron injection layer (EIL), the ETR may include, for example, LiF, lithium 8-hydroxyquinoline (LiQ), Li₂O, BaO, NaCl, CsF, lanthanides (such as Yb), and / or metal halides (such as RbCl and / or RbI). However, embodiments of the inventive concept are not limited thereto. The electron injection layer (EIL) may also be formed using a mixture of an electron injection material and an insulating organometallic salt. The organometallic salt may be a material having a band gap of about 4 eV or greater. In one embodiment, the organometallic salt may include, for example, a metal acetate, a metal benzoate, a metal acetoacetate, a metal acetylacetonate, and / or a metal stearate. The thickness of the electron injection layer (EIL) may be about [missing information]. to approximately Or it could be an agreement to approximately If the thickness of the electron injection layer EIL satisfies the above range, satisfactory electron injection performance can be obtained without significantly increasing the driving voltage.

[0130] The electron transport region ETR can include the hole blocking layer HBL as described above. The hole blocking layer HBL can include, for example, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and / or 4,7-diphenyl-1,10-phenanthroline (Bphen). However, embodiments of the inventive concept are not limited thereto.

[0131] The second electrode EL2 is disposed on the electron transport region ETR. The second electrode EL2 can be a common electrode or a cathode. The second electrode EL2 can be a transmissive electrode, a transreflective electrode, or a reflective electrode. For example, the second electrode EL2 can 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 can include a composite of two 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, a mixture of two 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, or an oxide of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn, and Zn. If the second electrode EL2 is a transmissive electrode, the second electrode EL2 can include a transparent metal material, for example, ITO, IZO, ZnO, ITZO, or the like.

[0132] If the second electrode EL2 is a transreflective electrode or a reflective electrode, the second electrode EL2 can include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, a composite thereof, or a mixture thereof (for example, a mixture of Ag and Mg). The second electrode EL2 can have a multi-layer structure including a reflective layer or a transreflective layer formed using the above-described materials and a transparent conductive layer formed using ITO, IZO, ZnO, ITZO, or the like.

[0133] In one embodiment, the second electrode EL2 can be connected with the auxiliary electrode. If the second electrode EL2 is connected with the auxiliary electrode, the resistance of the second electrode E2 can be reduced.

[0134] Further, a cap layer CPL can be further provided on the second electrode EL2 of the organic electroluminescent device 10 of the embodiment. The cap layer CPL can include, for example, α-NPD, NPB, TPD, m-MTDATA, Alq3, CuPc, N4,N4,N4’,N4’-Tetrakis(3-methyl-phenyl)-N,N-bis(1-phenyl-1H-benzimidazol-2-yl)-benzene (TPD15), 4,4’,4”-Tris(3-methylphenylphenylamino)-triphenylamine (TCTA), or the like.

[0135] The organic electroluminescent device 10 according to the embodiment of the inventive concept includes the fused polycyclic compound of the embodiment in the emission layer EML provided 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 embodiment can be a thermally activated delayed fluorescence dopant, and the emission layer EML can include the fused polycyclic compound of the embodiment to emit thermally activated delayed fluorescence. Accordingly, high emission efficiency performance can be achieved.

[0136] In addition, the fused polycyclic compound of the embodiment can 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 embodiment of the inventive concept can include the fused polycyclic compound in at least one of the organic layers provided between the first electrode EL1 and the second electrode EL2 or in the cap layer CPL provided on the second electrode EL2.

[0137] When compared with the prior art DABNA series compound including only N or B as a ring-forming heteroatom, the fused polycyclic compound of the embodiment must include Si as a ring-forming heteroatom forming a fused ring, and has a relatively high lowest triplet excited energy level (T1 level), and thus, if used as a material for an organic electroluminescent device, the efficiency of the organic electroluminescent device can be further improved.

[0138] Hereinafter, the fused polycyclic compound according to the embodiment and the organic electroluminescent device according to the embodiment of the inventive concept will be described with reference to Examples and Comparative Examples. The following Examples are merely illustrative, to assist in the understanding of the inventive concept, and the scope of the inventive concept is not limited thereto.

[0139] Example

[0140] 1. Synthesis of Fused Polycyclic Compound

[0141] First, the synthesis method of the fused polycyclic compound according to the exemplary embodiment will be specifically described with reference to the synthesis methods of Compound 2, Compound 5, Compound 14, Compound 15, and Compound 18. In addition, the synthesis method of the fused polycyclic compound described below is merely an embodiment, and the synthesis method of the fused polycyclic compound according to the embodiment of the inventive concept is not limited thereto.

[0142] (1) Synthesis of compound 2

[0143] The fused polycyclic compound 2 according to the embodiment can be synthesized, for example, by the following steps [1-1] to [1-6].

[0144] [1-1] Preparation of bis(2-bromophenyl)amine

[0145]

[0146] In a 500 mL three-necked round-bottom flask, 2-bromoaniline (15 g, 0.087 mol) and 1-bromo-2-iodobenzene (29.6 g, 0.105 mol) were dissolved in 200 mL of toluene, and then, to this, sodium tert-butoxide (16.76 g, 0.174 mol), Pd(dppf)Cl2(12.43 g, 0.017 mol), and tri-tert-butylphosphine (1.82 g, 0.009 mol) were added, and then, refluxed and stirred for about 12 hours. After the completion of the reaction, the solvent was removed, and extraction was performed three times with dichloromethane. The extracted organic layer was dried with anhydrous MgSO4, and the solvent was removed using a rotary evaporator. Then, the crude product thus obtained was separated by column chromatography using n-hexane as a solvent to obtain 18.3 g (yield = 64%) of the compound (colorless oil).

[0147] [1-2] Preparation of N,N-bis(2-bromophenyl)-N-(4-methoxybenzyl)amine

[0148]

[0149] Under a nitrogen atmosphere, bis(2-bromophenyl)amine (39 g, 119.2 mmol), NaH (3.43 g, 143.1 mmol), and 250 mL of DMF were put (e.g., added) into a 500 mL three-necked round-bottom flask that was sufficiently dried, and stirred at room temperature (about 25°C) for about 1 hour. Then, 1-(chloromethyl)-4-methoxybenzene (20.54 g, 131.2 mmol) was added dropwise thereto, and then, stirred at room temperature for about 14 hours. After the completion of the reaction, 500 mL of distilled water was added dropwise to the reaction product, filtered, and the precipitated solid was separated. The thus filtered solid was re-dissolved in dichloromethane and extracted three times. The extracted organic layer was dried with anhydrous MgSO4, and the solvent was removed using a rotary evaporator. The crude product was separated by column chromatography using dichloromethane (MC) / hexane = 3:1 solvent to obtain 46.8 g (yield = 87%) of the compound.

[0150] [1-3] Preparation of 5-(4-methoxybenzyl)-10,10-diphenyl-5,10-dihydrodibenzo[b,e][1,4]azasilane

[0151]

[0152] Into (e.g., added to) a 150 mL three-necked round-bottom flask, which was sufficiently dried, 2-bromo-N-(2-bromophenyl)-N-(4-methoxybenzyl)aniline (9.00 g, 20.1 mmol) and 60 mL of diethyl ether were put, and stirred. The reaction temperature was cooled to about 0°C, and 2.5M n-BuLi / hex (17.7 mL, 44.2 mmol) was added dropwise thereto. After stirring for about 30 minutes while maintaining the reaction temperature, dichlorodiphenylsilane (5.6 g, 22.1 mmol) dissolved in 20 mL of diethyl ether was added dropwise thereto, and then stirred at room temperature for about 4 hours. After the reaction was completed, the solvent was removed, extracted with ethyl acetate three times. The extracted organic layer was dried with anhydrous MgSO4, and the solvent was removed using a rotary evaporator. The crude product thus obtained was separated by column chromatography using dichloromethane / hexane (3 / 1) solvent to obtain 7.8 g (yield = 75%) of the compound.

[0153] [1-4] Preparation of 10,10-diphenyl-5,10-dihydrodibenzo[b,e][1,4]azasilane

[0154]

[0155] Into a 150 mL three-necked round-bottom flask, which was sufficiently dried, 5-(4- methoxybenzyl)-10,10-diphenyl-5,10-dihydrodibenzo[b,e][1,4]azasilane (37 g, 78.8 mmol), DDQ (19.67 g, 86.6 mmol), 370 mL of toluene, and 37 mL of H2O were put, and stirred at about 80°C for about 14 hours. After the reaction was completed, the solvent was removed, extracted with ethyl acetate three times. The extracted organic layer was dried with anhydrous MgSO4, and the solvent was removed using a rotary evaporator. The crude product thus obtained was separated by column chromatography using hexane / ethyl acetate (EA) (7 / 1) solvent to obtain 7.5 g (yield = 27%) of the compound.

[0156] [1-5] Preparation of 5-(2-bromophenyl)-10,10-diphenyl-5,10-dihydrodibenzo[b,e][1,4]azasilane

[0157]

[0158] In a 250 mL three-necked round-bottom flask, 10,10-diphenyl-5,10- dihydrodibenzo[b,e][1,4]azasilole (5 g, 0.014 mol) and 1-bromo-2-iodobenzene (4.05 g, 0.014 mol) were dissolved in 130 mL of toluene, and then, to this, sodium tert-butoxide (2.75 g, 0.029 mol), tri-tert-butylphosphine (0.29 g, 0.0014 mol), and Pd2(dba)3(0.65 g, 0.0007 mol) were added, and then, refluxed and stirred for about 12 hours. After the completion of the reaction, the solvent was removed, and extracted three times with dichloromethane. The extracted organic layer was dried with anhydrous MgSO4, and the solvent was removed using a rotary evaporator. The crude product thus obtained was separated by column chromatography using MC / hexane solvent to obtain 4 g (yield = 55%) of the compound.

[0159] [1-6] Preparation of Compound 2

[0160]

[0161] Dissolved 5-(2-bromophenyl)-10,10-diphenyl-5,10-dihydrodibenzo[b,e][1,4]azasilole (1 eq) in THF and cooled to about -78°C, and then, to this, n-BuLi (2.2 eq) was slowly added. After stirring at low temperature for about 2 hours, a solution obtained by dissolving mesitylboronic acid dimethyl ester (2.0 eq) in THF was added to the reactor. After stirring at about -78°C for about 1 hour, stirring at room temperature was performed for about 2 hours. Then, the reaction mixture was refluxed and stirred at about 80°C for about 24 hours, and then, poured into an aqueous NH4Cl solution to complete the reaction. The reaction product was extracted three times with distilled water and EA, dried with anhydrous MgSO4, and dried under reduced pressure. The organic layer thus obtained was separated by column chromatography (MC / hex) to obtain Compound 2 (yield: 15%).

[0162] (2) Synthesis of Compound 15

[0163] The fused polycyclic compound 15 according to the embodiment can be synthesized, for example, by the following steps [2-1] to [2-3].

[0164] [2-1] Preparation of 3-bromo-2-chloro-N,N-diphenylaniline

[0165]

[0166] In a 250 mL three-necked round-bottom flask, 1,3-dibromo-2-chlorobenzene (10 g, 0.037 mol) and diphenylamine (6.3 g, 0.037 mol) were dissolved in 130 mL of toluene, and then, to this, sodium tert-butoxide (7.11 g, 0.074 mol), tri-tert-butylphosphine (0.75 g, 0.004 mol), and Pd2(dba)3(1.7 g, 0.002 mol) were added, and then, refluxed and stirred for about 12 hours. After the completion of the reaction, the solvent was removed, and extraction was performed three times with dichloromethane. The extracted organic layer was dried with anhydrous MgSO4, and the solvent was removed using a rotary evaporator. Then, the crude product thus obtained was separated by column chromatography using MC / n-hexane solvent to obtain 5 g (yield = 38%) of 3-bromo-2-chloro-N,N-diphenyl aniline.

[0167] [2-2] Preparation of 2-chloro-3-(10,10-diphenyl-5,10-dihydrodibenzo[b,e][1,4] azasilin-5(10H)-yl)-N,N-diphenyl aniline

[0168]

[0169] In a 250 mL three-necked round-bottom flask, 3-bromo-2-chloro-N,N-diphenyl aniline (5 g, 0.014 mol) and 10,10-diphenyl-5,10-dihydrodibenzo[b,e][1,4] azasilane (4.87 g, 0.014 mol) were dissolved in 70 mL of toluene, and then, to this, sodium tert-butoxide (2.7 g, 0.028 mol), tri-tert-butylphosphine (0.3 g, 0.001 mol), and Pd2(dba)3(0.64 g, 0.0007 mol) were added, and then, refluxed and stirred for about 12 hours. After the completion of the reaction, the solvent was removed, and extraction was performed three times with dichloromethane. The extracted organic layer was dried with anhydrous MgSO4, and the solvent was removed using a rotary evaporator. The crude product was separated by column chromatography using MC / hexane solvent to obtain 5 g (yield = 57%) of 2-chloro-3-(10,10-diphenyl-5,10-dihydrodibenzo[b,e][1,4] azasilin-5(10H)-yl)-N,N-diphenyl aniline.

[0170] [2-3] Preparation of Compound 15

[0171]

[0172] To a flask containing 2-chloro-3-(10,10-diphenyl-5,10-dihydrodibenzo[b,e][l,4] azasila-5(10H)-yl)-N,N-diphenylaniline and tert-butylbenzene (150 mL) was added 1.7 M tert-butyllithium pentane solution (27.6 mL) at about -30 °C under a nitrogen atmosphere. After the end of the dropwise addition, the temperature was raised to about 60 °C and stirring was performed for about 2 hours. Then, components having a lower boiling point than that of tert-butylbenzene were removed by distillation under reduced pressure. The temperature was cooled to about -30 °C, to which was added boron tribromide (5.1 mL), and then the temperature was raised to room temperature and stirring was performed for about 0.5 hours. Thereafter, the temperature was cooled to about 0 °C and to which was added N,N-diisopropylethylamine (15.6 mL). Stirring was performed until the heat was cooled, the temperature was raised to about 120 °C and heating and stirring were performed for about 3 hours. The reaction solution was cooled to room temperature, extracted with a cooled aqueous sodium acetate solution, and separated by a column. The solid obtained by removing the solvent under reduced pressure was dissolved in toluene and recrystallized by adding hexane to obtain compound 15 (6.0 g).

[0173] 2, Manufacture and evaluation of organic electroluminescent device including fused polycyclic compound

[0174] (Manufacture of organic electroluminescent device)

[0175] The organic electroluminescent device of the examples including the fused polycyclic compound of the examples in the emission layer was manufactured by the following method. The organic electroluminescent devices of Examples 1 to 5 were manufactured using the fused polycyclic compounds of compound 2, compound 5, compound 14, compound 15, and compound 18, respectively, as the respective dopant materials for the emission layer. The organic electroluminescent device of Comparative Example 1 was manufactured using the comparative compound Cl as the dopant material in the emission layer.

[0176] On a glass substrate, ITO was patterned with a thickness of about 120 nm and washed with isopropanol and ultrapure water, washed with ultrasonic waves, exposed to UV for about 30 minutes, and treated with ozone. Then, NPD was deposited to a thickness of about 20 nm to form a hole injection layer, TCTA was deposited to a thickness of about 20 nm, and CzSi was deposited to a thickness of about 20 nm to form a hole transport layer. On the hole transport layer, DPEPO and each of the fused polycyclic compounds of the inventive examples or the comparative compound Cl were co-deposited in a ratio of 90:10 to form an emission layer having a thickness of about 30 nm. On the hole transport layer, DPEPO and each of the fused polycyclic compounds of the inventive examples or the comparative compound Cl were co-deposited in a ratio of 90:10 to form an emission layer having a thickness of about 30 nm.

[0177] On the hole transport layer, DPEPO and each of the fused polycyclic compounds of the inventive examples or the comparative compound Cl were co-deposited in a ratio of 90:10 to form an emission layer having a thickness of about 30 nm. ​​thickness of the emission layer. That is, the emission layer formed by co-deposition was formed by mixing and depositing Compound 2, Compound 5, Compound 14, Compound 15, and Compound 18 in Examples 1 to 5, respectively, with DPEPO or by mixing and depositing Comparative Compound CI in Comparative Example 1 with DPEPO.

[0178] On the emission layer, DPEPO was used to form an electron transport layer having a thickness of about On the electron transport layer, TPBi was deposited to a thickness of about

[0179] The compounds used in Examples 1 to 5 and Comparative Example 1 are listed in Table 1 below.

[0180] Table 1

[0181]

[0182]

[0183] In addition, other compounds used for the manufacture of the organic electroluminescent device of Examples and Comparative Example 1 are shown below.

[0184]

[0185] (Evaluation of Performance of Organic Electroluminescent Device)

[0186] In Table 2, the evaluation results of the organic electroluminescent device of Examples 1 to 5 and Comparative Example 1 are shown. In Table 2, the driving voltage, emission efficiency, and external quantum efficiency (EQE) of the organic electroluminescent device thus manufactured are shown and compared.

[0187] As shown in Table 2, in the evaluation results of the performance of the examples and comparative examples, the voltage and current density were measured using a source meter (Keithley Instrument Co., SMU 236). The emission efficiency indicates the current efficiency with respect to a current density of 10 mA / cm 2

[0188] Table 2

[0189]

[0190]

[0191] ​​​​Referring to the results in Table 2, 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 a material for an emission layer exhibits similar driving voltage values and relatively high emission efficiency and external quantum efficiency when compared with the comparative example.

[0192] When compared with Comparative Compound C1, in the case of the example compound, the multiple resonance phenomenon using aromatic rings, which form a fused ring, shows TADF performance, and can have high rigidity and bulkiness by including Si as a ring-forming heteroatom, which forms a fused ring. Accordingly, the organic electroluminescent device of the example can show improved emission efficiency compared with the organic electroluminescent device of the comparative example.

[0193] The fused polycyclic compound of the embodiment includes a fused ring structure including Si as a ring-forming heteroatom, and has a high T1 energy level and a small △E ST value, and thus can be used as a delayed fluorescence emission material. In addition, the fused polycyclic compound of the embodiment can be used as a dopant material of an emission layer in an organic electroluminescent device to improve device efficiency. In addition, the fused polycyclic compound of the embodiment includes a fused ring structure including Si as a ring-forming heteroatom, and can show high rigidity and long lifetime characteristics.

[0194] The organic electroluminescent device of the embodiment includes the fused polycyclic compound of the embodiment, and can exhibit improved emission efficiency. In addition, the organic electroluminescent device of the embodiment includes the fused polycyclic compound of the embodiment as a material for an emission layer, and can achieve high emission efficiency in a blue wavelength region.

[0195] The organic electroluminescent device according to the embodiment can show improved device characteristics with reduced driving voltage and high efficiency.

[0196] The fused polycyclic compound of the embodiment can be included in an emission layer of an organic electroluminescent device, and can contribute to improving the efficiency of the organic electroluminescent device.

[0197] When a phrase such as“at least one of’ or“at least one selected from a set of’ appears in the specification, the phrase is intended to cover the set of elements specified and any subset of the specified elements, but not the empty set. For instance, the phrases“at least one of a and b” and“at least one selected from the group consisting of a and b” are intended to cover a, b, or a and b. Furthermore, to the extent that the term“includes” is used in the detailed description and claims, such term is intended to be inclusive in a manner similar to“comprising” as“comprising” is interpreted when employed as a transitional word in the transitional phrase“comprising a.” Furthermore, the term“exemplary” is intended to refer to an example and is not intended to indicate a preference as used by the phrase“preferably.” As used herein, the terms“substantially,”“approximately,” and similar terms are used as terms of approximation and not as terms of degree, unless otherwise indicated, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. Additionally, any numerical ranges recited herein are intended to include all sub-ranges encompassed therein. For example, a range of“1.0 to 10.0” is intended to include all sub-ranges, half- ranges, and whole ranges based upon the same minimum and maximum values, e.g., 2.4 to 7.6, 5.5 to 6.9, or 3.0 to 6.0, etc. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, the applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited in this specification. All such ranges are intended to be inherently described in this specification such that amendment to expressly recite any such sub-ranges would conform to the requirements of 35 U.S.C. § 112, first paragraph, and 35 U.S.C. § 132(a).

[0198] While exemplary embodiments of the application have been described, it is to be understood that the application is not to be limited to those examples, but is capable of numerous modifications and alternative constructions and methods of carrying out the application as set forth above in the spirit and scope of the application as set forth in the appended claims.

Claims

1. An organic electroluminescent device comprising: a first electrode; a second electrode opposite to the first electrode; and a plurality of organic layers between the first electrode and the second electrode, wherein each of the first electrode and the second electrode 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, or independently includes a composite of two 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, a mixture of two 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, or an oxide of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn, and Zn, wherein at least one of the plurality of organic layers includes a fused polycyclic compound represented by the following Formula 1-1: Formula 1-1 wherein, in Formula 1-1, X1 is B, n is an integer of 0 to 5, and R c and R d are each independently a hydrogen atom, a deuterium atom, or a substituted or unsubstituted aryl group of 6 to 60 ring-forming carbon atoms, R n is 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 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms, and R n is optionally combined with an adjacent group to form a ring, 2.The organic electroluminescent device according to claim 1, wherein R 11 to R 21 each independently is a hydrogen atom, a deuterium atom, a halogen atom, a boron group, a substituted or unsubstituted amine group, a substituted or unsubstituted alkyl group of 1 to 20 carbon atoms, a substituted or unsubstituted aryl group of 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group of 2 to 60 ring-forming carbon atoms. the fused polycyclic compound represented by Formula 1-1 has an absolute value of a difference between a lowest singlet excitation energy level and a lowest triplet excitation energy level of 0.1 eV or less. the fused polycyclic compound represented by Formula 1-1 is any one selected from the following Compound Group 1:

3. The organic electroluminescent device according to claim 1, wherein R c and R d are each independently unsubstituted phenyl.

4. The organic electroluminescent device according to claim 1, wherein Compound Group 1 the plurality of organic layers include:

5. The organic electroluminescent device according to claim 1, wherein 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, and the emission layer includes the fused polycyclic compound represented by Formula 1-1. The emission layer emits delayed fluorescence.

6. The organic electroluminescent device according to claim 5, wherein 7.The organic electroluminescent device according to claim 5, wherein the emission layer is a delayed fluorescence emission layer including a host and a dopant, and the dopant includes the fused polycyclic compound represented by Formula 1-1. the emission layer includes:

8. The organic electroluminescent device according to claim 5, wherein 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, and the first dopant includes the fused polycyclic compound represented by Formula 1-1. 9.The organic electroluminescent device according to claim 8, wherein the first dopant is a delayed fluorescence dopant, and the second dopant is a fluorescent dopant. ​

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