Condensed ring compound

Abstract

Provided are an organic electroluminescent device and a condensed ring compound for the organic electroluminescent device. The organic electroluminescent device includes a first electrode, a second electrode, and an emission layer disposed between the first electrode and the second electrode, in which the emission layer includes a condensed ring compound represented by Formula 1, and the organic electroluminescent device exhibits high efficiency characteristics: Formula 1 wherein X1 to X6, Ar1, Ar2, l, m, n, a to g, and R1 to R8 are the same as defined in the specification.

Description

[0001] This application is a divisional application of the invention patent application filed on January 25, 2021, with application number 202110096043.4 and entitled "Organic electroluminescent device and condensed ring compound for use therein". Technical Field

[0002] One or more aspects of embodiments of this disclosure relate to organic electroluminescent devices and condensed ring compounds used in the organic electroluminescent devices, for example, to condensed ring compounds used as luminescent materials and organic electroluminescent devices comprising the condensed ring compounds. Background Technology

[0003] Organic light-emitting displays (OLEDs) are being developed as image display devices. Unlike liquid crystal displays (LCDs), OLEDs are so-called self-emissive display devices. In self-emissive display devices, holes and electrons injected from the first and second electrodes recombine in the emitting layer, allowing the light-emitting organic material in the emitting layer to emit light and achieve display.

[0004] When applying organic electroluminescent devices to display devices, there is a demand for organic electroluminescent devices with low driving voltage, high luminous efficiency and / or long lifespan, which requires the continuous development of materials that can reliably obtain such characteristics of organic electroluminescent devices.

[0005] Recently, in order to realize efficient organic electroluminescent devices, materials utilizing phosphorescence (using triplet energy), delayed fluorescence (using triplet-triplet annihilation (TTA) (where singlet excitons are generated through collisions of triplet excitons)), and / or thermally activated delayed fluorescence (TADF) are being developed. Summary of the Invention

[0006] One or more aspects of embodiments of this disclosure relate to an organic electroluminescent device exhibiting excellent luminous efficiency.

[0007] One or more aspects of embodiments of this disclosure relate to a condensation ring compound as a material for organic electroluminescent devices having high efficiency characteristics.

[0008] One or more exemplary embodiments of this disclosure provide condensed ring compounds represented by Formula 1: Formula 1 .

[0009] In Formula 1, X1 to X6 can each be independently a direct bond, BAr3, NAr4, O, or S; Ar1 ​​to Ar4 can each be independently a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms. l, m, and n can each be independently 0 or 1, and at least one of l, m, and n can be 1; a to g can each be independently an integer from 0 to 4 (in some embodiments, a to g can be constrained to, for example, an integer from 0 to 2, depending on the values ​​of l, m, and / or n). R1 to R8 may each be independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted oxygen group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms, and R1 to R8 may optionally be attached to adjacent groups to form a ring.

[0010] In the embodiments, Equation 1 can be represented by any of Equations 1-1 to 1-3. In Equations 1-1 to 1-3, X1 to X6, Ar1, Ar2, l, m, n, a to g, and R1 to R8 can all be independently the same as those defined in Equation 1: Equation 1-1

[0011] Formula 1-2

[0012] Formula 1-3 .

[0013] In the embodiments, Equation 1 can be represented by any of Equations 1-A to 1-E. In Equations 1-A to 1-E, X1 to X6, Ar1, Ar2, a to g, and R1 to R8 can all be independently identical to those defined in Equation 1: Formula 1-A

[0014] Formula 1-B

[0015] Formula 1-C

[0016] Formula 1-D

[0017] Formula 1-E .

[0018] In the embodiments, Ar1 to Ar4 can each be independently an unsubstituted phenyl, a substituted or unsubstituted alkyl-substituted phenyl having 1 to 10 carbon atoms, or a phenyl substituted with a deuterium atom.

[0019] In some embodiments, for example, all of R1 to R8 may (e.g., simultaneously) be deuterium atoms.

[0020] One or more exemplary embodiments of this disclosure provide condensed ring compounds represented by Formula 1A: Formula 1A .

[0021] In Formula 1A, Ar1 and Ar2 can each be independently a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms. l, m, and n can each be independently 0 or 1, at least one of l, m, and n can be 1, and d to g can each be independently an integer from 0 to 4. R4 to R8 can each be independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted oxygen group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms, and R4 to R8 can optionally be bonded to adjacent groups to form a ring, and HAr1 to HAr3 can each be independently represented by Formula 2: Formula 2 .

[0022] In Formula 2, Y and Z can each be independently a straight bond, BAr3, NAr4, O, or S. Ar3 and Ar4 can each be independently a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms; r can be an integer from 0 to 4; Ra can be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted oxygen group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms, and Ra can optionally be bonded to an adjacent group to form a ring. "" indicates the point connected to Equation 1A.

[0023] In the embodiments, Equation 1A can be represented by any of Equations 1A-1 to 1A-5. In Equations 1A-1 to 1A-5, Ar1, Ar2, d to g, and R4 to R8 can all be independently identical to those defined in Equation 1A, and HAr1 to HAr3 can all be independently identical to those defined in Equation 1A. Formula 1A-1

[0024] Formula 1A-2

[0025] Formula 1A-3

[0026] Formula 1A-4

[0027] Formula 1A-5 .

[0028] In the embodiments, Equation 2 can be represented by any of Equations 2-A to 2-J. In Equations 2-A to 2-J, Ar3, Ar4, Ra, and r can all be independently the same as those defined in Equation 2:

[0029]

[0030] .

[0031] In the embodiments, Ar1 to Ar4 can each be independently an unsubstituted phenyl, a substituted or unsubstituted alkyl-substituted phenyl having 1 to 10 carbon atoms, or a phenyl substituted with a deuterium atom.

[0032] One or more exemplary embodiments of this disclosure provide an organic electroluminescent device, the organic electroluminescent device comprising: a first electrode; a second electrode disposed on the first electrode; and an emitting layer located between the first electrode and the second electrode, and comprising the condensed ring compound of the above embodiments. The first electrode and the second electrode may each independently comprise any one selected from the following substances: Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Zn, Sn, and Yb; Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Zn, Sn, and Yb. Two or more of the following compounds; mixtures 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, Zn, Sn and Yb; and oxides of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Zn, Sn and Yb.

[0033] The emission layer can emit delayed fluorescence.

[0034] The emitter layer may include a host and a dopant, and the dopant may include the condensed ring compound.

[0035] The emitting layer can emit light with a center wavelength of approximately 460 nm to approximately 490 nm. Attached Figure Description

[0036] The accompanying drawings, which are included in and form part of this specification, are provided to provide a further understanding of this disclosure. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the disclosure. In the drawings: Figure 1 This is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the present disclosure; Figure 2 This is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the present disclosure; Figure 3 This is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the present disclosure; and Figure 4 This is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the present disclosure. Detailed Implementation

[0037] This disclosure may include various modifications and may be implemented in different forms, as illustrated in the accompanying drawings. However, this disclosure may be implemented in different forms and should not be construed as limiting oneself to the embodiments set forth herein. Rather, all modifications, equivalents, and substitutions are to be understood as being included within the spirit and scope of this disclosure.

[0038] In this description, it will be understood that when an element (region, layer, and / or portion, etc.) is referred to as being "on" another element, "connected to," or "bonded to" another element or layer, the element may be directly on, directly connected to, or directly bonded to the other element, or an intermediate third element may be disposed between the element and the other element. Conversely, when an element is referred to as being "directly on" another element, "directly connected to," or "directly bonded to" another element, there is no intermediate element.

[0039] The same reference numerals always denote the same components, and their repeated descriptions are not required. Furthermore, in the accompanying drawings, the thickness, proportions, and dimensions of components may be exaggerated for the purpose of effective description of the technical content.

[0040] As used herein, the term “and / or” includes any and all combinations of one or more of the relevant listed items.

[0041] It will be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, the elements are not limited by these terms. These terms are used only to distinguish one element from another. For example, without departing from the scope of exemplary embodiments of this disclosure, a first element may be optionally named a second element, and similarly, a second element may be optionally named a first element. Unless the context clearly indicates otherwise, singular terms may include plural forms.

[0042] Furthermore, terms such as "below," "under," "above," and / or "above" are used to describe the relationships of the structures shown in the accompanying drawings. These terms are used as relative concepts and are described with reference to the directions indicated in the drawings.

[0043] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will also be understood that terms defined in a general dictionary shall be interpreted as having the meaning consistent with their meaning in the context of the relevant field and shall not be interpreted in an idealized or overly formalized sense unless expressly defined herein.

[0044] It should be understood that the terms “comprising” and / or “including” and variations thereof are intended to indicate the presence of the stated features, integrals, steps, operations, elements, components or combinations thereof in the disclosure, but do not preclude the presence or addition of one or more other features, integrals, steps, operations, elements, components or combinations thereof.

[0045] As used herein, expressions such as “at least one of…”, “one of…”, and “selected from…” modify the entire column of elements when they follow (before) a list of elements, but not individual elements within that column. Furthermore, when describing embodiments of this disclosure, the use of “may” indicates “one or more embodiments of this disclosure”.

[0046] In the following description, an organic electroluminescent device according to an embodiment of the present disclosure and a condensed ring compound included therein will be described with reference to the accompanying drawings.

[0047] Figures 1 to 4 This is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the present disclosure. (Refer to...) Figures 1 to 4 In each organic electroluminescent device 10, the first electrode EL1 and the second electrode EL2 are arranged to face each other, and the emission layer EML is disposed between the first electrode EL1 and the second electrode EL2.

[0048] In addition to the emitter layer EML Figures 1 to 4 Each of the organic electroluminescent devices 10 may further include multiple functional layers located between the first electrode EL1 and the second electrode EL2. The multiple functional layers may include a hole transport region (HTR) and an electron transport region (ETR). For example, each of the organic electroluminescent devices 10 according to an embodiment may include a first electrode EL1, a hole transport region (HTR), an emitter layer (EML), an electron transport region (ETR), and a second electrode EL2, stacked sequentially. In some embodiments, the organic electroluminescent device 10 may include a capping layer (CPL) disposed on the second electrode EL2.

[0049] The organic electroluminescent device 10 of the embodiment may include (described below) a condensation ring compound in the emitter layer EML disposed between the first electrode EL1 and the second electrode EL2. In some embodiments, the organic electroluminescent device 10 of the embodiment may include a condensation ring compound in the hole transport region HTR and / or the electron transport region ETR (the hole transport region HTR and the electron transport region ETR are disposed among a plurality of functional layers between the first electrode EL1 and the second electrode EL2), or it may include a condensation ring compound in the emitter layer EML.

[0050] and Figure 1 In comparison, Figure 2A cross-sectional view of an organic electroluminescent device 10 according to an embodiment is shown. In this organic electroluminescent device 10, the hole transport region HTR includes a hole injection layer HIL and a hole transport layer HTL, and the electron transport region ETR includes an electron injection layer EIL and an electron transport layer ETL. Figure 1 In comparison, Figure 3 A cross-sectional view of an organic electroluminescent device 10 according to an embodiment is shown. In this organic electroluminescent device 10, 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 In comparison, Figure 4 A cross-sectional view of an organic electroluminescent device 10 according to an embodiment is shown. The organic electroluminescent device 10 also includes a capping layer CPL disposed on a second electrode EL2.

[0051] The first electrode EL1 may be conductive. The first electrode EL1 may be formed of a metal alloy and / or a conductive compound. The first electrode EL1 may be an anode. Furthermore, the first electrode EL1 may be a pixel electrode. The first electrode EL1 may be a transmissive electrode (e.g., a transparent electrode), a transmissive-reflective electrode, or a reflective electrode. When the first electrode EL1 is a transmissive electrode, it may include a transparent metal oxide (such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO)). When the first electrode EL1 is a transmissive / reflective electrode or a reflective electrode, the first electrode EL1 may include silver (Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), LiF / Ca, LiF / Al, molybdenum (Mo), titanium (Ti), indium (In), zinc (Zn), tin (Sn), ytterbium (Yb), compounds thereof (e.g., AgMg, AgYb, or MgYb), mixtures thereof, or oxides thereof. In some embodiments, the first electrode EL1 may have a multilayer structure, which includes a reflective or transmissive layer formed of the above-described materials and a transmissive (transparent) conductive layer formed of ITO, IZO, ZnO, ITZO, etc. For example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO, but is not limited thereto. The thickness of the first electrode EL1 can be from about 1,000 Å to about 10,000 Å, for example, from about 1,000 Å to about 3,000 Å.

[0052] A 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, for example, from about 50 Å to about 15,000 Å.

[0053] The hole transport region (HTR) can have a single layer formed of a single material, a single layer formed of multiple different materials, or a multilayer structure including multiple layers formed of multiple different materials.

[0054] 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 it can have a single-layer structure formed of a hole injection material and a hole transport material. In some embodiments, the hole transport region HTR can have a single-layer structure formed of a variety of different materials, or it can have a structure in which hole injection layer HIL / hole transport layer HTL, hole injection layer HIL / hole transport layer HTL / hole buffer layer, hole injection layer HIL / hole buffer layer, hole transport layer HTL / hole buffer layer, or hole injection layer HIL / hole transport layer HTL / electron blocking layer EBL are stacked sequentially from the first electrode EL1, but the embodiments are not limited thereto.

[0055] Hole transport regions (HTRs) can be formed using any suitable method, such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing and / or laser-induced thermal imaging (LITI).

[0056] Hole injection layer HIL can include, for example, phthalocyanine compounds (such as copper phthalocyanine), N,N'-diphenyl-N,N'-bis[4-(di-m-tolyl-amino)-phenyl]-biphenyl-4,4'-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-phenylethyl) Poly(phenylene oxide) sulfonate (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), polyaniline / camphor sulfonic acid (PANI / CSA), polyaniline / poly(4-styrene sulfonate) (PANI / PSS), N,N'-di(naphthyl-1-yl)-N,N'-diphenyl-benzidine (NPB), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetra(pentafluorophenyl)borate, dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexaonitrile (HAT-CN), etc.

[0057] Hole transport layers (HTLs) 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"-tris(N-carbazolyl)triphenylamine (TCTA)), N,N'-bis(naphthyl-1-yl)-N,N'-diphenyl-biphenylamine (NPB), 4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl (HMTPD), 1,3-bis(N-carbazolyl)benzene (mCP), etc.

[0058] The thickness of the hole transport region (HTR) can be approximately 50 Å to approximately 10,000 Å, for example, approximately 100 Å to approximately 5,000 Å. The thickness of the hole injection layer (HIL) can be, for example, approximately 30 Å to approximately 1,000 Å, and the thickness of the hole transport layer (HTL) can be approximately 30 Å to approximately 1,000 Å. For example, the thickness of the electron blocking layer (EBL) can be approximately 10 Å to approximately 1,000 Å. When 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 properties can be achieved without significantly increasing the driving voltage.

[0059] In addition to the materials described above, the hole transport region (HTR) may also include a charge-generating material to improve conductivity. The charge-generating material may be substantially 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 a quinone derivative, a metal oxide, or a cyano-containing compound, but is not limited thereto. For example, non-limiting examples of p-dopers include quinone derivatives (such as tetracyanoquinone dimethyl (TCNQ) and / or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinone dimethyl (F4-TCNQ)), metal oxides (such as tungsten oxide and / or molybdenum oxide), etc., but are not limited thereto.

[0060] As described above, in addition to the hole injection layer (HIL) and the hole transport layer (HTL), the hole transport region (HTR) may also include at least one of a hole buffer layer and an electron blocking layer (EBL). The hole buffer layer can compensate for the resonant distance of the wavelength of light emitted from the emitter layer (EML) and can improve the luminous efficiency of the device. Materials that can be included in the hole transport region (HTR) may be incorporated into the hole buffer layer. The electron blocking layer (EBL) can prevent or reduce the injection of electrons from the electron transport region (ETR) into the hole transport region (HTR).

[0061] The emitter layer (EML) is disposed on the hole transport region (HTR). The thickness of the emitter layer (EML) can be, for example, from about 100 Å to about 1,000 Å or from about 100 Å to about 300 Å. The emitter layer (EML) can have a single layer formed of a single material, a single layer formed of multiple different materials, or a multilayer structure having multiple layers formed of multiple different materials.

[0062] The emission layer EML in the organic electroluminescent device 10 of the embodiment may include the condensed ring compound of the embodiment.

[0063] The condensed ring compounds of the embodiments can be classified as 1,3,5-triamino-2,4-diboryl-benzene derivatives condensed with heterocycles (e.g., one or more heterocycles). Furthermore, the condensed ring compounds of the embodiments can be classified as benzoazaborine, as represented by formula X. ") and / or dibenzoazaborine, The condensation ring of formula X is further condensed with a heterocycle. In some embodiments, the heterocycle further incorporated into the condensation ring represented by formula X may include at least one of B, N, O, and S as a heteroatom.

[0064] Formula X

[0065] In the description, the term "substituted or unsubstituted" can mean an unsubstituted state (e.g., containing only hydrogen) or a state substituted with at least one substituent selected from the group consisting of deuterium, halogen, cyano, nitro, amino (or amine), silyl, oxy, thio, sulfinyl, sulfonyl, carbonyl, boryl, phosphonyl oxide, phosphonyl sulfide, alkyl, alkenyl, alkynyl, alkyloxy, cycloalkyl, aryl, and heterocyclic groups. Furthermore, each of the substituents listed above may be further substituted or unsubstituted. For example, biphenyl can be interpreted as aryl or a phenyl group substituted with a phenyl group.

[0066] In the description, the term "bonded to an adjacent group to form a ring" can refer to the state of bonding to an adjacent group to form a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle. The term "hydrocarbon ring" includes aliphatic hydrocarbon rings and aromatic hydrocarbon rings. The term "heterocycle" includes aliphatic heterocycles and aromatic heterocycles. The ring formed by bonding to an adjacent group can be monocyclic or polycyclic. Furthermore, rings formed by bonding to each other can connect to another ring to form a spirostructure.

[0067] In the description, the term "adjacent group" can refer to a substituent on the same atom or at the same position, a substituent directly attached to an atom of a base atom or at a base position, or (e.g., within the intramolecular bonding distance) a substituent spatially adjacent to the corresponding substituent. For example, the two methyl groups in 1,2-dimethylbenzene can be interpreted as "adjacent groups" to each other, and the two ethyl groups in 1,1-diethylcyclopentane can be interpreted as "adjacent groups" to each other.

[0068] In the description, non-limiting examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.

[0069] In the description, the alkyl group can be a straight-chain alkyl group, a branched alkyl group, or a cycloalkyl group. The number of carbon atoms in the alkyl group can be from 1 to 50, from 1 to 30, from 1 to 20, from 1 to 10, or from 1 to 6. Non-limiting examples of alkyl groups include, but are not limited to, 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, undecyl, dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl, heptadecanyl, octadecyl, nonadecanyl, eicosyl, 2-ethyleicosyl, 2-butyleicosyl, 2-hexyleicosyl, 2-octyleicosyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, hexadecyl, octadecyl, nonadecanyl, triadecyl, etc.

[0070] In this description, the term "aryl" refers to any functional group or substituent derived from an aromatic hydrocarbon ring. Aryl groups can be monocyclic or polycyclic. The number of cyclic carbon atoms in an aryl group can be 6 to 30, 6 to 20, or 6 to 15. Non-limiting examples of aryl groups include phenyl, naphthyl, fluorenyl, anthracene, phenanthryl, biphenyl, terphenyl, tetraphenyl, pentaphenyl, hexaphenyl, benzo[9,10]phenanthryl, pyrene, benzofluoranthracene, phenyl, etc.

[0071] In the description, the heterocyclic group may include at least one of boron (B), oxygen (O), nitrogen (N), phosphorus (P), silicon (Si), and sulfur (S) as a heteroatom. When the heterocyclic group contains two or more heteroatoms, the two or more heteroatoms may be the same or different from each other. The heterocyclic group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group, or it may be a heteroaryl group. The number of cyclic carbon atoms in the heterocyclic group may be 2 to 30, 2 to 20, or 2 to 10.

[0072] In the description, a heteroaryl group may include at least one of B, O, N, P, Si, and S as a heteroatom. When a heteroaryl group contains two or more heteroatoms, the two or more heteroatoms may be the same as or different from each other. A heteroaryl group may be a monocyclic or polycyclic heteroaryl group. The number of cyclic carbon atoms in the heteroaryl group may be 2 to 30, 2 to 20, or 2 to 10. Non-limiting examples of heteroaryl groups include thiophene, furanyl, pyrrole, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridinel, pyridazinyl, pyrazinyl, quinolinyl, quinazolinyl, quinoxalinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, isoquinolinyl, and indoleyl. Carbazolyl, N-arylcarbazolyl, N-heteroarylcarbazolyl, N-alkylcarbazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothiophene, dibenzothiophene, thiophene-thiophene, benzofuranyl, phenanthrolinel, isoxazolyl, thiadiazolyl, phenothiazolyl, phenothiazinyl, dibenzothiophene, dibenzofuranyl, etc., but not limited to these.

[0073] In the description, the term "oxy group" may refer to an alkoxy group or an aryloxy group. An alkoxy group may include a straight-chain, branched, or cyclic chain. The number of carbon atoms in an alkoxy group is not particularly limited, but may, for example, be from 1 to 20 or from 1 to 10. The number of cyclic carbon atoms in an aryloxy group may, for example, be from 6 to 30, from 6 to 20, or from 6 to 15. Non-limiting examples of oxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, pentoxy, hexoxy, octoxy, nonoxy, decoxy, benzyloxy, etc.

[0074] In the description, the term "thio group" may refer to alkathio or arylthio. In the description, the alkyl group in alkathio can be the same as the alkyl group mentioned above.

[0075] In the description, the aryl group in aryloxy and arylthio groups can be the same as the aryl group mentioned above.

[0076] In the description, the number of carbon atoms in the amino group is not limited, but can be from 1 to 30. The amino group can include alkylamino, arylamino, or heteroarylamino. Non-limiting examples of amino groups include methylamino, dimethylamino, phenylamino, diphenylamino, naphthylamino, 9-methyl-anthraylamino, etc.

[0077] In the description, the term "direct linkage" can refer to a single bond. A direct linkage can refer to two directly connected positions that are bonded without any additional connecting atoms or connecting groups.

[0078] In the description, " "Indicates the position to be connected.

[0079] The emitting layer EML in the organic electroluminescent device 10 of the embodiment may include the condensed ring compound represented by Formula 1 of the embodiment: Formula 1 .

[0080] In Equation 1, X1 through X6 can each be independently a direct bond, BAr3, NAr4, O, or S. As mentioned above, a "direct bond" can refer to a single bond (e.g., such that the resulting ring is quinary). Two heteroatoms (X1 and X2, X3 and X4, and / or X5 and X6) in a heterocycle (as contained in parentheses with l, m, and / or n) can each be independently identical or different from one another.

[0081] In Formula 1, Ar1 to Ar4 can each be independently a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms. For example, Ar1 to Ar4 can each be independently an unsubstituted phenyl, a substituted or unsubstituted alkyl-substituted phenyl having 1 to 10 carbon atoms, or a phenyl substituted with a deuterium atom. Furthermore, when Ar1 to Ar4 are all substituted or unsubstituted alkyl-substituted phenyl groups having 1 to 10 carbon atoms, Ar1 to Ar4 can each be a phenyl group substituted with at least one isopropyl group.

[0082] In Formula 1, l, m, and n can each be independently 0 or 1, and at least one of l, m, and n can be 1. For example, in the condensed ring compound of the embodiment, the case where l, m, and n are all 0 is excluded. For example, the condensed ring compound of the embodiment can have a condensed ring represented by Formula X as described above and can be further condensed with a heterocycle. For example, the heterocycle can include at least one of B, N, O, and S as a heteroatom.

[0083] In Equation 1, a through g can each be an independent integer from 0 to 4. In some embodiments, when a through g are each an independent integer of 2 or greater, the plurality of R1 to R7 can each be independently identical, at least one of the plurality of R1 to R7 can be different from the others, or each of the plurality of R1 to R7 can be different. Furthermore, when a is an integer of 2 or greater, the plurality of R1 can all be identical, or at least one R1 can be different from the others. This is described as an example; this can be equivalently applied to R2 through R7 when each of b through g is an integer of 2 or greater. Meanwhile, when l is 1, d can be an integer from 0 to 2, when m is 1, e can be an integer from 0 to 2, and when n is 1, f can be an integer from 0 to 2.

[0084] In Formula 1, R1 to R8 can each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted oxygen group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms, and R1 to R8 can optionally be bonded to adjacent groups to form a ring. For example, R1 to R8 can each independently be a hydrogen atom, a deuterium atom, a methyl group, an unsubstituted oxygen group, an alkoxy group, an unsubstituted thio group, an aryloxy group, or a phenyl group. However, the examples are not limited thereto. R1 to R8 can all be hydrogen atoms, or R1 to R8 can all be deuterium atoms.

[0085] When R1 through R8 bind to adjacent groups to form a ring, the resulting ring can be a heterocycle that includes heteroatoms such as N, O, and S as cyclic atoms. For example, R7 can bind to the nitrogen atom of a neighboring benzozaborane ring to form an indoline ring, a benzoxazine ring, or a benzothiazine ring.

[0086] The condensed ring compound represented by Formula 1 can be represented by any one of Formulas 1-1 to 1-3. Formulas 1-1 to 1-3 each represent example structures including condensed heterocycles at different bonding positions.

[0087] Equation 1-1

[0088] Formula 1-2

[0089] Formula 1-3

[0090] In Equations 1-1 to 1-3, X1 to X6, Ar1, Ar2, l, m, n, a to g, and R1 to R8 can all be independently the same as those described in Equation 1.

[0091] The condensed ring compound of the embodiments represented by Formula 1 has at least one heterocycle, which is further bonded (fused) to a condensed ring of a core represented by Formula X. For example, the condensed ring compound of the embodiments may have one or at least two (e.g., two) heterocycles further bonded to a core represented by Formula X, and the at least two heterocycles may be bonded to different positions (e.g., different rings).

[0092] For example, the condensed ring compound of the embodiment can be represented by any of Formula 1-A to Formula 1-E. Formula 1-A and Formula 1-B both represent the case in which a heterocycle is further condensed, and Formulas 1-C to Formula 1-E all represent the case in which two heterocycles are condensed to different positions (rings).

[0093] Formula 1-A Formula 1-B Formula 1-C Formula 1-D Formula 1-E

[0094] In Equations 1-A to 1-E, X1 to X6, Ar1, Ar2, a to g, and R1 to R8 can all be independently identical to those described in Equation 1.

[0095] In some embodiments, the condensed ring compound of the embodiment may be represented by Formula 1A: Formula 1A .

[0096] The substituents and variables in Equation 1A can all be independently the same as those described in Equation 1.

[0097] In Formula 1A, Ar1 and Ar2 can each be independently a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms. For example, Ar1 and Ar2 can each be independently an unsubstituted phenyl group, a substituted or unsubstituted alkyl-substituted phenyl group having 1 to 10 carbon atoms, or a phenyl group substituted with a deuterium atom. Furthermore, when both Ar1 and Ar2 are substituted or unsubstituted alkyl-substituted phenyl groups having 1 to 10 carbon atoms, both Ar1 and Ar2 can be phenyl groups substituted with at least one isopropyl group.

[0098] In Equation 1A, l, m, and n can all be independently 0 or 1, and at least one of l, m, and n can be 1. For example, the case where l, m, and n are all 0 is excluded.

[0099] In Formula 1A, d to g can each be an independent integer from 0 to 4. R4 to R8 can each be an independent hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted oxygen group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms, and R4 to R8 can optionally be attached to adjacent groups to form a ring.

[0100] In some embodiments, in Equation 1A, HAr1 to HAr3 can each be independently represented by Equation 2: Formula 2 .

[0101] In Formula 2, Y and Z can each be independently a straight bond, BAr3, NAr4, O, or S. Ar3 and Ar4 can each be independently a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms. For example, Ar3 and Ar4 can each be independently an unsubstituted phenyl group, a substituted or unsubstituted alkyl-substituted phenyl group having 1 to 10 carbon atoms, or a phenyl group substituted with a deuterium atom.

[0102] In Equation 2, r can be an integer from 0 to 4. When r is an integer of 2 or greater, multiple Ra can be the same, or at least one Ra can be different from the others.

[0103] Ra can be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted oxygen group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms, and Ra can optionally be incorporated into an adjacent group to form a ring. In Formula 2, " " is the part that is incorporated into Equation 1A.

[0104] The heterocycle represented by Equation 2 can be represented by any one of Equations 2-A to 2-J:

[0105]

[0106] .

[0107] In Equations 2-A to 2-J, the substituents and variables described in Equation 2 as above can be applied equivalently to Ar3, Ar4, Ra, and r.

[0108] Equation 1A can be represented by any of Equations 1A-1 to 1A-5. Each of Equations 1A-1 and 1A-2 represents the case where a heterocyclic ring represented by Equation 2 is condensed into the core portion represented by Equation 1A. Furthermore, each of Equations 1A-3 to 1A-5 represents the case where two heterocyclic rings represented by Equation 2 are condensed into different positions of the core portion represented by Equation 1A.

[0109] Formula 1A-1 Formula 1A-2 Formula 1A-3 Formula 1A-4 Formula 1A-5

[0110] The condensed ring compounds of the embodiments described above may have a structure in which one or more heterocycles are bonded to a core comprising a condensed benzo[a]borane ring or a dibenzo[a]borane ring, thereby providing an expanded conjugated system. Therefore, the conjugated structure can provide multiple resonance structures, thereby promoting reverse intersystem crossing (RISC). Thus, the condensed ring compounds of the embodiments having expanded conjugated structures can be used as highly efficient luminescent materials. For example, if the condensed ring compounds according to the embodiments are used as emitter layer materials in organic electroluminescent devices, the luminous efficiency of the organic electroluminescent devices can be improved.

[0111] Due to the expanded conjugated system structure, the condensed ring compounds of the embodiments have a molecular structure in which reverse intersystem crossing readily occurs; therefore, these condensed ring compounds can be used as thermally activated delayed fluorescence (TADF) materials. For example, the condensed ring compounds of the embodiments can be used as TADF materials that emit blue light.

[0112] The condensed ring compound of the embodiments may be selected from the (condensed ring) compounds represented by compound group 1. The organic electroluminescent device 10 of the embodiments may include at least one condensed ring compound from the condensed ring compounds represented by compound group 1 in the emitting layer EML.

[0113] Compound group 1

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124] In some embodiments, as illustrated in part by the examples of compounds 1-D to 3-D, at least one hydrogen atom in the condensed ring compound of the embodiment may be substituted with a deuterium atom. For example, any hydrogen atom in the condensed ring compound according to the embodiment may be substituted with a deuterium atom.

[0125] For example, compared to, for example, compound 1, the condensed ring compounds of the embodiments can be substantially similar to compounds 1-D by having a structure in which hydrogen atoms are replaced by deuterium atoms. Therefore, compound group 1 is understood to provide additional deuterated structures in which any hydrogen atom is replaced by a deuterium atom.

[0126] The condensed ring compounds of the embodiments can be used as blue luminescent materials. For example, the condensed ring compounds according to the embodiments can be used to emit a central wavelength (λ) having a light-emitting center wavelength in the wavelength region of approximately 490 nm or less. max The condensed ring compound of the embodiments can be a luminescent material that emits blue light having a central emission wavelength in the wavelength region of about 460 nm to about 490 nm. The condensed ring compound of Formula 1 in the embodiments can be a blue thermally activated delayed fluorescence dopant.

[0127] The condensed ring compound of the embodiments can be a thermally activated delayed fluorescence emitting material. The emission layer EML of the organic electroluminescent device 10, which includes the condensed ring compound of the embodiments, can emit delayed fluorescence. For example, the emission layer EML can emit thermally activated delayed fluorescence (TADF).

[0128] In some embodiments, the organic electroluminescent device 10 of the embodiment may include multiple emitting layers. The multiple emitting layers may be stacked sequentially; for example, the organic electroluminescent device 10 including multiple emitting layers may emit white light. The organic electroluminescent device 10 including multiple emitting layers may be an organic electroluminescent device having a tandem (or "cascaded") structure. When the organic electroluminescent device 10 includes multiple emitting layers, at least one emitting layer EML may include the condensed ring compound of the embodiments described above.

[0129] In embodiments, the emitter layer EML includes a host and a dopant, and may include the condensation ring compound of the above embodiments as a dopant. For example, the emitter layer EML in the organic electroluminescent device 10 of the embodiments may include a host for emitting delayed fluorescence and a dopant for emitting delayed fluorescence, and may include the condensation ring compound of the above embodiments as a dopant for emitting delayed fluorescence. The emitter layer EML may include at least one of the condensation ring compounds represented by compound group 1 as a thermally activated delayed fluorescence dopant.

[0130] In this embodiment, the emission layer EML is a delayed fluorescence emission layer, and the emission layer EML may comprise any suitable host material and the condensation ring compound described in the above embodiments. For example, in this embodiment, the condensation ring compound may be used as a TADF dopant.

[0131] In embodiments, the emitter layer EML may comprise any suitable host material. For example, in embodiments, the emitter layer EML may comprise tris(8-hydroxyquinoline)aluminum (Alq3), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), poly(N-vinylcarbazole) (PVK), 9,10-bis(naphthyl-2-yl)anthracene (ADN), 4,4',4''-tris(carbazolyl-9-yl)-triphenylamine (TCTA), 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 2-tert-butyl-9,10-bis(naphthyl-2-yl)anthracene (TBADN), distyrylarylene (DSA), 4,4'-bis(8-hydroxyquinoline)aluminum (Alq3), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), poly(N-vinylcarbazole) (PVK), 9,10-bis(naphthyl-2-yl)anthracene (ADN), 4,4'-bis(N-hydroxyquinoline)-1,1'-biphenyl (CBP), poly(N-vinylcarbazole) (PVK), 9,10-bis(naphthyl-2-yl)anthracene (ADN), 4,4'-bis(naphthyl-9-yl)-triphenylamine (TCTA), 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 2-tert-butyl-9,10-bis(naphthyl-2-yl)anthracene (TBADN), distyrylarylene (DSA), 4,4'-bis(naphthyl-2-yl)anthracene (ADN (9-Carbazolyl)-2,2'-dimethylbiphenyl (CDBP), 2-methyl-9,10-bis(naphthyl-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(diphenylphospho)dibenzo[b,d]furan (PPF), 3,3'-bis(N-carbazolyl)-1,1'-biphenyl (mCBP), 1,3-bis(N-carbazolyl)benzene (mCP), etc., can be used as host materials. However, the examples are not limited to these and may include other suitable delayed fluorescence emission host materials.

[0132] The emitter layer EML in the organic electroluminescent device 10 of the embodiment may also include any suitable dopant material. In the embodiment, the emitter layer EML may also include styrene derivatives (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styrene]benzene (DPAVB) and N-(4-((E)-2-(6-((E)-4-(diphenylamino)styrene)naphth-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-dipyrenebenzene, 1,4-bis(N,N-diphenylamino)pyrene) as dopant materials.

[0133] exist Figures 1 to 4In the organic electroluminescent device 10 of the embodiment shown, the electron transport region (ETR) is disposed on the emitter layer (EML). The electron transport region (ETR) may include at least one of the hole blocking layer (HBL), the electron transport layer (ETL), and the electron injection layer (EIL), but the embodiment is not limited thereto. The electron transport region (ETR) may have a single layer formed of a single material, a single layer formed of multiple different materials, or a multilayer structure including multiple layers formed of multiple different materials.

[0134] For example, the electron transport region (ETR) can have a monolayer structure of either an electron injection layer (EIL) or an electron transport layer (ETL), or it can have a monolayer structure formed of an electron injection material and an electron transport material. The ETR can have a monolayer structure formed of a variety of different materials, or it can have a structure in which electron transport layer (ETL) / electron injection layer (EIL) or hole blocking layer (HBL) / electron transport layer (ETL) / electron injection layer (EIL) are stacked sequentially from the emitter layer (EML), but is not limited thereto. The thickness of the ETR can be, for example, from approximately 1000 Å to approximately 1500 Å.

[0135] The electron transport region (ETR) can be formed using any suitable method (such as vacuum deposition, spin coating, casting, Langmuir-Blodget (LB) method, inkjet printing, laser printing, laser-induced thermal imaging (LITI) method, etc.).

[0136] When the electron transport region (ETR) includes an electron transport layer (ETL), the ETR may include anthracene compounds. However, the embodiments are not limited thereto, and the ETR may include, for example, tris(8-hydroxyquinoline)aluminum (Alq3), 1,3,5-tris[(3-pyridyl)-benzene-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- The electron transport layer (ETL) can be approximately 100 Å to approximately 1,000 Å, for example, approximately 150 Å to approximately 500 Å. Other electron transport layers include: 4-(naphth-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), bis(benzoquinoline-10-hydroxy)beryllium (Bebq2), 9,10-bis(naphth-2-yl)anthracene (ADN), 1,3-bis[3,5-bis(pyridin-3-yl)phenyl]benzene (BmPyPhB), or mixtures thereof. When the thickness of the electron transport layer (ETL) meets the above range, satisfactory electron transport characteristics can be obtained without significantly increasing the driving voltage.

[0137] When the electron transport region (ETR) includes an electron injection layer (EIL), the ETR can be formed using metal halides (such as LiF, NaCl, CsF, RbCl, and RbI), lanthanides (such as ytterbium (Yb)), metal oxides (such as Li₂O and / or BaO), or lithium 8-hydroxyquinoline (LiQ), but the embodiments are not limited thereto. The EIL can also be formed from a mixture of an electron transport material and an insulating organometallic salt. The organometallic salt can be a material having a band gap of approximately 4 eV or greater. The organometallic salt can include, for example, metal acetates, metal benzoates, metal acetoacetates, metal acetylacetonates, and / or metal stearates. The thickness of the EIL can be from approximately 1 Å to approximately 100 Å or from approximately 3 Å to approximately 90 Å. When the thickness of the EIL meets the above ranges, satisfactory electron injection properties can be obtained without significantly increasing the driving voltage.

[0138] As described above, the electron transport region (ETR) may include a hole blocking layer (HBL). The hole blocking layer (HBL) may include, but is not limited to, at least one of, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and 4,7-diphenyl-1,10-phenanthroline (Bphen).

[0139] 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 transmission electrode, a transmission-reflection electrode, or a reflection electrode. When the second electrode EL2 is a transmission electrode, the second electrode EL2 can include a transparent metal oxide, such as ITO, IZO, ZnO, ITZO, etc.

[0140] When the second electrode EL2 is a transmissive or 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, In, Zn, Sn, Yb, or compounds or mixtures or oxides thereof (e.g., AgMg, AgYb, or MgYb). In some embodiments, the second electrode EL2 may have a multilayer structure, which includes a reflective or transmissive layer formed of the above-described materials and a transparent conductive layer formed of ITO, IZO, ZnO, ITZO, etc.

[0141] In some embodiments, the second electrode EL2 can be connected to an auxiliary electrode. When the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 can be reduced.

[0142] In some embodiments, a capping layer CPL may also be provided on the second electrode EL2 of the organic electroluminescent device 10 according to the embodiment. The capping layer CPL may include, for example, α-NPD, NPB, TPD, m-MTDATA, Alq3, CuPc, N4,N4',N4'-tetra(biphenyl-4-yl)biphenyl-4,4'-diamine (TPD15), 4,4',4"-tris(carbazole-9-yl)triphenylamine (TCTA), etc. However, the embodiments are not limited thereto, and the capping layer CPL may include amine compounds. For example, the capping layer CPL may include at least one of compound CPL1 and compound CPL2: .

[0143] In some embodiments, the refractive index of the capping CPL may be 1.6 or greater. For example, the refractive index of the capping CPL may be 1.6 or greater relative to light in the wavelength range of approximately 550 nm to approximately 660 nm.

[0144] The organic electroluminescent device 10 according to embodiments of the present disclosure may include the condensed ring compound described above in the emitter layer EML disposed between the first electrode EL1 and the second electrode EL2, thereby exhibiting excellent luminous efficiency. In some embodiments, the organic electroluminescent device 10 of the embodiments may exhibit high luminous efficiency in the blue light emission wavelength region. Furthermore, the condensed ring compound according to the embodiments may be a thermally activated delayed fluorescence dopant, and the emitter layer EML may include the condensed ring compound of the embodiments to emit thermally activated delayed fluorescence, thereby achieving good luminous efficiency characteristics.

[0145] In addition to the emitting layer EML, the condensation ring compound described above can be included in the organic layer (e.g., a second organic layer or a separate organic layer). For example, the organic electroluminescent device 10 according to an embodiment of this disclosure may also include the condensation ring compound described above in at least one functional layer disposed between the first electrode EL1 and the second electrode EL2 or in the capping layer CPL disposed on the second electrode EL2.

[0146] The condensed ring compounds of the above embodiments may include heterocyclic structures condensed and incorporated into a core moiety containing a benzo[a]azaborane or dibenzo[a]azaborane, thereby providing an expanded conjugated system. Therefore, the condensed ring compounds of the embodiments can be used as luminescent materials exhibiting high efficiency characteristics due to the increased resonance effect in the molecule. Furthermore, organic electroluminescent devices of the embodiments comprising the condensed ring compounds of the embodiments in the emitting layer can emit blue light and exhibit high efficiency characteristics.

[0147] In the following, condensation ring compounds and organic electroluminescent devices according to embodiments of the present disclosure will be described in more detail with reference to examples and comparative examples. Furthermore, the examples shown below are merely illustrative for understanding the present disclosure, and the scope of the disclosure is not limited thereto.

[0148] Example 1. Example Synthesis of Condensed Cyclic Compounds First, a method for synthesizing condensed ring compounds according to the present embodiment will be described by way of example synthesis of compounds 1, 2, 3, 41, 52, 55, and 67. The following methods are provided as examples, but the synthesis methods according to embodiments of this disclosure are not limited to the examples below.

[0149] (1) Synthesis of compound 1 Compound 1 according to the example can be synthesized by, for example, the steps (activities) shown in reaction 1: Reaction 1 .

[0150] Synthesis of intermediate A In an argon (Ar) atmosphere, 1,3-dibromo-5-chlorobenzene (50.0 g), diphenylamine (62.6 g), bis(dibenzylacetone)palladium(O) (Pd(dba)2, 2.12 g), 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (SPhos, 1.56 g), and sodium tert-butoxide (NaO) were added to a 1000 mL three-necked flask. t Bu (36.0 g) was dissolved in 500 mL of toluene and heated under reflux for 2 hours. After cooling to room temperature, water was added to the reaction mixture, and the product was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate A (74.4 g, 90% yield). The molecular weight of intermediate A was 446, as measured by FAB-MS.

[0151] Synthesis of intermediate B In an Ar atmosphere, intermediate A (35.0 g), aniline (10.9 g), Pd(dba)2 (0.45 g), SPhos (0.32 g), and NaO were added to a 500 mL three-necked flask. t Bu (11.3 g) was dissolved in 200 mL of toluene and heated under reflux for 1 hour. After cooling to room temperature, water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified in ethanol by sonication to obtain intermediate B (37.1 g, 94% yield). The molecular weight of intermediate B was determined to be 503 by FAB-MS.

[0152] Synthesis of intermediate C The intermediate C, a azirborane derivative, was synthesized according to the following literature: Park, S. et al., “High-Performance Dibenzoheteraborin-Based Thermally Activated Delayed Fluorescence Emittors: Molecular Architectonics for Concurrently Achieving Narrowband Emission and Efficient Triplet–Singlet Spin Conversion”. Adv. Funct. Mater.2018, 28, 1802031; the full content of this document is incorporated herein by reference.

[0153] Synthesis of intermediate D In an Ar atmosphere, intermediate B (10.0 g), intermediate C (10.7 g), Pd(dba)2 (0.11 g), SPhos (0.08 g), and NaO were added to a 500 mL three-necked flask. t Bu (1.91 g) was dissolved in 100 mL of toluene and heated under reflux for 3 hours. Water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was dried over anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate D (16.9 g, yield 89%). The molecular weight of intermediate D was determined to be 959 by FAB-MS.

[0154] Synthesis of Compound 1 In an Ar atmosphere, intermediate D (16.0 g) was added to a 300 mL three-necked flask and dissolved in 100 mL of o-dichlorobenzene (ODCB), and the mixture was cooled to 0 °C in an ice bath. Boron triiodide (BI3, 19.6 g) was added, and the mixture was heated and stirred at 150 °C for 18 hours. The mixture was then cooled to 0 °C in an ice bath, and 25 mL of triethylamine was added. After the temperature returned to room temperature, the reaction solution was filtered through a silica gel filter, and residual solvent was removed by vacuum distillation. The crude product was purified by recrystallization from toluene to obtain compound 1 (1.20 g, 7% yield). The molecular weight of compound 1 was determined to be 974 by FAB-MS.

[0155] (2) Synthesis of compound 2 Compound 2 according to the example can be synthesized by, for example, the steps shown in reaction 2: Reaction 2 .

[0156] Synthesis of intermediate E The intermediate E, an oxaborine derivative, was synthesized according to the following literature: Numata, M. et al., “High efficiency pure blue thermally activated delayed fluorescence molecules having 10H-phenoxaborin and acridan units”. Chem. Commun. 2015, 51, 9443-9446; the full content of this document is incorporated herein by reference.

[0157] Synthesis of intermediate F In an Ar atmosphere, intermediate B (10.0 g), intermediate E (9.16 g), Pd(dba)2 (0.11 g), SPhos (0.08 g), and NaO were added to a 500 mL three-necked flask. t Bu (1.91 g) was dissolved in 100 mL of toluene and heated under reflux for 3 hours. After cooling to room temperature, water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate F (16.1 g, 92% yield). The molecular weight of intermediate F was determined to be 883 by FAB-MS.

[0158] Synthesis of Compound 2 In an Ar atmosphere, intermediate F (16.0 g) was added to a 300 mL three-necked flask, dissolved in 100 mL of ODCB, and cooled to 0 °C in an ice bath. Then, BI3 (19.6 g) was added, and the mixture was heated and stirred at 150 °C for 18 hours. The mixture was cooled to 0 °C in an ice bath, and 25 mL of triethylamine was added. After the temperature returned to room temperature, the reaction solution was filtered through a silica gel filter, and residual solvent was removed by vacuum distillation. The crude product was purified by recrystallization from toluene to obtain compound 2 (1.01 g, 6% yield). The molecular weight of compound 2 was determined to be 899 by FAB-MS.

[0159] (3) Synthesis of compound 3 Compound 3 according to the example can be synthesized by, for example, the steps shown in reaction 3: Reaction 3 .

[0160] Synthesis of intermediate G The intermediate G, a thioborane derivative, was synthesized according to the following literature: Park, S. et al., “High-Performance Dibenzoheteraborin-Based Thermally Activated Delayed Fluorescence Emittors: Molecular Architectonics for Concurrently Achieving Narrowband Emission and Efficient Triplet–Singlet Spin Conversion”. Adv. Funct. Mater. 2018, 28, 1802031.

[0161] Synthesis of intermediate H In an Ar atmosphere, intermediate B (10.0 g), intermediate G (9.48 g), Pd(dba)2 (0.11 g), SPhos (0.08 g), and NaO were added to a 500 mL three-necked flask. t Bu (1.91 g) was dissolved in 100 mL of toluene and heated under reflux for 3 hours. Water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate H (15.3 g, yield 86%). The molecular weight of intermediate H was determined to be 900 by FAB-MS.

[0162] Synthesis of Compound 3 In an Ar atmosphere, intermediate H (15.0 g) was added to a 300 mL three-necked flask, dissolved in 100 mL of ODCB, and cooled to 0 °C in an ice bath. Then, BI3 (19.6 g) was added, and the mixture was heated and stirred at 150 °C for 18 hours. The mixture was cooled to 0 °C in an ice bath, and 23 mL of triethylamine was added. After the temperature returned to room temperature, the reaction solution was filtered through a silica gel filter, and residual solvent was removed by vacuum distillation. The crude product was recrystallized from toluene and purified to obtain compound 3 (0.87 g, 6% yield). The molecular weight of compound 3 was determined to be 915 by FAB-MS.

[0163] (4) Synthesis of compound 41 Compound 41 according to the example can be synthesized by, for example, the steps shown in reaction 4: Reaction 4 .

[0164] Synthesis of intermediate J In an Ar atmosphere, intermediate B (15.0 g), 3-bromo-10-phenylphenoxazine (10.1 g), Pd(dba)₂ (0.17 g), SPhos (0.12 g), and NaO were added to a 500 mL three-necked flask. t Bu (2.86 g) was dissolved in 100 mL of toluene and heated under reflux for 3 hours. Water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate J (17.4 g, 77% yield). The molecular weight of intermediate J was determined to be 760 by FAB-MS.

[0165] Synthesis of Compound 41 In an Ar atmosphere, intermediate J (15.0 g) was added to a 300 mL three-necked flask and dissolved in 100 mL of ODCB. The mixture was then cooled to 0 °C in an ice bath, and BI3 (19.6 g) was added. The mixture was heated and stirred at 150 °C for 18 hours. The mixture was then cooled to 0 °C in an ice bath, and 27 mL of triethylamine was added. After the temperature returned to room temperature, the reaction solution was filtered through a silica gel filter, and residual solvent was removed by vacuum distillation. The crude product was purified by recrystallization from toluene to obtain compound 41 (1.84 g, 12% yield). The molecular weight of compound 41 was determined to be 776 by FAB-MS.

[0166] (5) Synthesis of compound 52 Compound 52 according to the example can be synthesized by, for example, the steps shown in reaction 5: Reaction 5

[0167] .

[0168] Synthesis of intermediate K In an Ar atmosphere, 2-bromo-10-phenylphenoxazine (30.0 g), aniline (8.26 g), Pd(dba)₂ (0.51 g), SPhos (0.36 g), and NaO were added to a 1000 mL three-necked flask. tBu (8.52 g) was dissolved in 300 mL of toluene and heated under reflux for 1 hour. Water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate K (23.3 g, 75% yield). The molecular weight of intermediate K was determined to be 350 by FAB-MS.

[0169] Synthesis of intermediate L In an Ar atmosphere, 1,3,5-tribromobenzene (50.0 g), diphenylamine (26.8 g), Pd(dba)2 (0.91 g), bis(diphenylphosphine)ferrocene (dppf, 1.76 g), and NaO were added to a 1000 mL three-necked flask. t Bu (15.3 g) was dissolved in 300 mL of toluene and heated under reflux for 2 hours. Water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate L (25.6 g, 40% yield). The molecular weight of intermediate L was determined to be 403 by FAB-MS.

[0170] Synthesis of intermediate M In an Ar atmosphere, intermediate L (10.0 g), intermediate K (17.4 g), Pd(dba)2 (0.14 g), SPhos (0.10 g), and NaO were added to a 500 mL three-necked flask. t Bu (4.80 g) was dissolved in 100 mL of toluene and heated under reflux for 3 hours. Water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate M (15.9 g, yield 68%). The molecular weight of intermediate M was determined to be 942 by FAB-MS.

[0171] Synthesis of Compound 52 In an Ar atmosphere, intermediate M (15.0 g) was added to a 300 mL three-necked flask, dissolved in 100 mL of ODCB, and cooled to 0 °C in an ice bath. Then, BI3 (19.6 g) was added, and the mixture was heated and stirred at 150 °C for 18 hours. The mixture was cooled to 0 °C in an ice bath, and 22 mL of triethylamine was added. After the temperature returned to room temperature, the reaction solution was filtered through a silica gel filter, and residual solvent was removed by vacuum distillation. The crude product was purified by recrystallization from toluene to obtain compound 52 (2.09 g, 14% yield). The molecular weight of compound 52 was determined to be 957 by FAB-MS.

[0172] (6) Synthesis of compound 55 Compound 55 according to the example can be synthesized by, for example, the steps shown in reaction 6: Reaction 6 .

[0173] Synthesis of intermediate N In an Ar atmosphere, 2-bromo-dibenzo-p-dioxin (30.0 g), aniline (10.6 g), Pd(dba)₂ (0.66 g), SPhos (0.46 g), and NaO were added to a 1000 mL three-necked flask. t Bu (11.0 g) was dissolved in 400 mL of toluene and heated under reflux for 3 hours. Water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate N (21.9 g, 70% yield). The molecular weight of intermediate N was determined to be 275 by FAB-MS.

[0174] Synthesis of intermediate O In an Ar atmosphere, intermediate N (20.0 g), intermediate L (14.6 g), Pd(dba)2 (0.41 g), SPhos (0.30 g), and NaO were added to a 1000 mL three-necked flask. t Bu (6.98 g) was dissolved in 250 mL of toluene and heated under reflux for 4 hours. Water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate O (18.7 g, 65% yield). The molecular weight of intermediate O was determined to be 791 by FAB-MS.

[0175] Synthesis of Compound 55 In an Ar atmosphere, intermediate O (15.0 g) was added to a 300 mL three-necked flask, dissolved in 100 mL of ODCB, and cooled to 0 °C in an ice bath. Then, BI3 (19.6 g) was added, and the mixture was heated and stirred at 150 °C for 18 hours. The mixture was cooled to 0 °C in an ice bath, and 26 mL of triethylamine was added. After the temperature returned to room temperature, the reaction solution was filtered through a silica gel filter, and residual solvent was removed by vacuum distillation. The crude product was purified by recrystallization from toluene to obtain compound 55 (2.73 g, 18% yield). The molecular weight of compound 55 was determined to be 807 by FAB-MS.

[0176] (7) Synthesis of compound 67 Compound 67 according to the example can be synthesized by, for example, the steps shown in reaction 7: Reaction 7 .

[0177] Synthesis of intermediate P In an Ar atmosphere, 2-bromo-9-phenyl-9H-carbazole (50.0 g), aniline (14.5 g), Pd(dba)2 (0.90 g), SPhos (0.64 g), and NaO were added to a 1000 mL three-necked flask. t Bu (14.9 g) was dissolved in 400 mL of toluene and heated under reflux for 3 hours. Water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate P (35.3 g, 68% yield). The molecular weight of intermediate P was determined to be 334 by FAB-MS.

[0178] Synthesis of intermediate Q In an Ar atmosphere, intermediate P (20.0 g), intermediate L (24.1 g), Pd(dba)2 (0.34 g), dppf (0.66 g), and NaO were added to a 1000 mL three-necked flask. t Bu (5.74 g) was dissolved in 200 mL of toluene and heated under reflux for 2 hours. Water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate Q (20.4 g, yield 52%). The molecular weight of intermediate Q was determined to be 656 by FAB-MS.

[0179] Synthesis of intermediate R In an Ar atmosphere, intermediate Q (19.0 g), intermediate K (10.1 g), Pd(dba)2 (0.16 g), SPhos (0.12 g), and NaO were added to a 500 mL three-necked flask. t Bu (2.78 g) was dissolved in 100 mL of toluene and heated under reflux for 3 hours. Water was added to the reaction mixture, and the mixture was extracted with CH2Cl2 to obtain an organic layer. The organic layer was then dried with anhydrous MgSO4, and the solvent was removed by vacuum distillation. The crude product was purified by silica gel column chromatography to obtain intermediate R (17.4 g, 65% yield). The molecular weight of intermediate R was determined to be 926 by FAB-MS.

[0180] Synthesis of Compound 67 In an Ar atmosphere, intermediate R (15.0 g) was added to a 300 mL three-necked flask, dissolved in 100 mL of ODCB, and cooled to 0 °C in an ice bath. Then, BI3 (19.6 g) was added, and the mixture was heated and stirred at 150 °C for 18 hours. The mixture was cooled to 0 °C in an ice bath, and 22 mL of triethylamine was added. After the temperature returned to room temperature, the reaction solution was filtered through a silica gel filter, and residual solvent was removed by vacuum distillation. The crude product was purified by recrystallization from toluene to obtain compound 67 (1.42 g, 9% yield). The molecular weight of compound 67 was determined to be 941 by FAB-MS.

[0181] 2. Fabrication and evaluation of organic electroluminescent devices An organic electroluminescent device comprising the condensation ring compound of the embodiments in the emitter layer is evaluated below. A method for manufacturing the organic electroluminescent device for device evaluation is described below.

[0182] Organic electroluminescent devices of Examples 1 to 7 were fabricated by using compounds 1, 2, 3, 41, 52, 55, and 67 as dopant materials in the emitter layer. Comparative Examples 1 to 3 are organic electroluminescent devices fabricated by using comparative example compound C1, comparative example compound C2, and comparative example compound C3 as emitter layer dopant materials, respectively.

[0183] The compounds used in Examples 1 to 7 and the compounds used in Comparative Examples 1 to 3 are listed in Table 1.

[0184] Table 1

[0185]

[0186] Manufacturing of organic electroluminescent devices A 1500 Å thick layer of ITO was patterned on a glass substrate, which was then washed with ultrapure water, irradiated with ultraviolet light for approximately 30 minutes, and treated with ozone. Subsequently, HAT-CN was deposited to a thickness of approximately 100 Å, α-NPD to a thickness of approximately 800 Å, and mCP to a thickness of approximately 50 Å to form hole transport regions.

[0187] To form the emission layer, an example condensed ring compound or a comparative example compound and a host material are co-deposited at a weight ratio of approximately 1:99 to form a layer 200 Å thick. For example, the emission layer is formed by mixing and co-depositing the host material with each of compounds 1, 2, 3, 41, 52, 55, and 67 from Examples 1 to 7, respectively, and by mixing and co-depositing the host material with each of comparative example compounds C1, C2, and C3 from Comparative Examples 1 to 3, respectively. When forming the emission layer, mCBP is used as the host material.

[0188] Then, a 300 Å thick layer was formed on the emitter layer using TPBi, followed by a 50 Å thick layer sequentially formed using LiF to form the electron transport region. Next, a second electrode with a thickness of approximately 1,000 Å was formed from aluminum (Al). A capping layer with a thickness of approximately 700 Å was then formed on the second electrode using the compound CPL1.

[0189] In both the example and comparative examples, a vacuum deposition apparatus is used to form the hole transport region, the emitter layer, the electron transport region, and the second electrode.

[0190] The compounds used in the fabrication of the various functional layers of organic electroluminescent devices are as follows: .

[0191] Evaluation of the characteristics of organic electroluminescent devices The evaluation results of the organic electroluminescent devices of Examples 1 to 7 and Comparative Examples 1 to 3 are listed in Table 2. Table 2 compares the maximum emission wavelength (λ) of the fabricated organic electroluminescent devices. max ) and luminous efficacy (EQE) MAX EQE 1000nit In the results, the maximum emission wavelength (λ) max ) represents the wavelength showing the maximum value in the emission spectrum, EQE MAX It is the maximum value of the external quantum efficiency, EQE 1000nit It is 1000 cd / m2 The value of the external quantum efficiency.

[0192] Table 2

[0193] Referring to the results in Table 2, it is confirmed that the organic electroluminescent devices of Examples 1 to 7 emit light in the blue wavelength region of 460 nm to 490 nm and exhibit higher luminous efficiency characteristics than those of Comparative Examples 1 to 3.

[0194] For example, Examples 1 to 7 exhibit higher maximum external quantum efficiency values ​​than Comparative Examples 1 to 3, at 1000 cd / m². 2 The external quantum efficiency value is also higher than that of 1000 cd / m² in Comparative Examples 1 to 3. 2 The external quantum efficiency value is high.

[0195] Compared to the comparative example compounds, the condensed ring compounds of the embodiments according to this disclosure have a structure in which the heterocycle is condensed with a benzo[a]borane or a dibenzo[a]borane, thereby providing an expanded conjugated system in a single compound structure. It is believed that this is the reason why the examples (using condensed ring compounds as emitter layer dopants) have improved efficiency compared to the comparative example compounds.

[0196] When comparative example compound C1 (used in comparative example 1) is compared with the example compounds used in examples 1 to 7, the example compounds have a form in which at least one heterocyclic group is condensed into the basic structure of comparative example compound C1. Therefore, it is confirmed that the luminescence intensity of the condensed ring compound is increased by the further condensed heterocyclic group.

[0197] Furthermore, when comparing Comparative Example Compound C2 (used in Comparative Example 2) with Example Compound 1, Example Compound 2, and Example Compound 3 (used in Examples 1 to 3), the Example Compounds have a condensation structure in which the boron atom is in the para position relative to the nitrogen atom of the benzozaborane, thus allowing for easier reverse intersystem crossing due to resonance effects in the molecule, compared to Comparative Example Compound C2. Therefore, it is considered that Examples 1 to 3 exhibit improved luminescence efficiency compared to Comparative Example 2.

[0198] The example condensed ring compounds can have structures including condensed heterocycles to expand the conjugated system in the molecule. The increased resonance effect reduces the difference between the triplet and singlet energy levels, thus allowing the example condensed ring compounds to exhibit high efficiency and thermally activated delayed fluorescence emission.

[0199] The example condensed-ring compound has a 1,3,5-triamino-2,4-diboronyl-benzene derivative as its core and includes multiple heterocycles condensed and linked to the boron and nitrogen atoms of the core moiety. Devices comprising this condensed-ring compound exhibit excellent emission characteristics. Furthermore, the expanded conjugated system provided by including a heterocycle further condensed to a core containing multiple benzozaboranes results in high luminous efficiency characteristics.

[0200] The example organic electroluminescent device may include an example condensed ring compound in the emitting layer to exhibit high luminous efficiency in the blue emission wavelength region.

[0201] The organic electroluminescent devices in the embodiments exhibit excellent luminous efficiency.

[0202] The condensed ring compound of the embodiment can be included in the emitting layer of the organic electroluminescent device to contribute to the high efficiency of the organic electroluminescent device.

[0203] Although this disclosure has been described with reference to embodiments thereof, it will be understood that this disclosure should not be limited to these embodiments, and various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of this disclosure.

[0204] As used herein, the terms “basically,” “about,” and similar terms are used as approximate terms rather than as terms of degree, and are intended to explain the inherent biases in measurements or calculations that will be recognized by one of ordinary skill in the art.

[0205] Therefore, the scope of this disclosure is not intended to be limited to the content set forth in the specific embodiments described in the specification, but is intended to be defined by the claims and their equivalents.

Claims

1. A condensed cyclic compound, said condensed cyclic compound being represented by Formula 1: Formula 1 ， in, In Equation 1, X1 to X6 are each independently a direct-connect key, BAr3, NAr4, O, or S. Ar1 to Ar4 are all independently substituted or unsubstituted aryl groups having 6 to 30 cyclic carbon atoms, or substituted or unsubstituted heteroaryl groups having 2 to 30 cyclic carbon atoms. l, m, and n are all independently 0 or 1, and at least one of l, m, and n is 1. a to g are all independent integers from 0 to 4, and R1 to R8 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted oxygen group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms, and R1 to R8 may optionally be attached to an adjacent group to form a ring.

2. The condensed ring compound according to claim 1, wherein, Equation 1 is represented by any one of Equations 1-1 to 1-3: Equation 1-1 Formula 1-2 Formula 1-3 ,and In Equations 1-1 to 1-3, X1 to X6, Ar1, Ar2, l, m, n, a to g, and R1 to R8 are all independently the same as those defined in Equation 1.

3. The condensed ring compound according to claim 1, wherein, Equation 1 is represented by any one of Equations 1-A to 1-E: Formula 1-A Formula 1-B Formula 1-C Formula 1-D Formula 1-E ,and In Equations 1-A to 1-E, X1 to X6, Ar1, Ar2, a to g, and R1 to R8 are all independently identical to those defined in Equation 1.

4. The condensed ring compound according to claim 1, wherein, Ar1 to Ar4 are each independently an unsubstituted phenyl, a substituted or unsubstituted alkyl-substituted phenyl with 1 to 10 carbon atoms, or a phenyl substituted with a deuterium atom.

5. The condensed ring compound according to claim 1, wherein, R1 to R8 are all deuterium atoms.

6. A condensed ring compound, said condensed ring compound being represented by formula 1A: Formula 1A ， in, In Equation 1A, Ar1 and Ar2 are both independently substituted or unsubstituted aryl groups having 6 to 30 cyclic carbon atoms, or substituted or unsubstituted heteroaryl groups having 2 to 30 cyclic carbon atoms. l, m, and n are all independently 0 or 1, and at least one of l, m, and n is 1. d to g are all independent integers from 0 to 4. R4 to R8 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted oxygen group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms, and R4 to R8 may optionally be attached to adjacent groups to form a ring. HAr1 to HAr3 are all independently represented by Equation 2: Formula 2 ,and In Equation 2, Both Y and Z are independently direct-connected keys, BAr3, NAr4, O, or S. Ar3 and Ar4 are both independently substituted or unsubstituted aryl groups having 6 to 30 cyclic carbon atoms, or substituted or unsubstituted heteroaryl groups having 2 to 30 cyclic carbon atoms. r is an integer from 0 to 4. Ra is a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted amino group, a substituted or unsubstituted oxygen group, a substituted or unsubstituted thio group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms, and Ra may optionally be incorporated into an adjacent group to form a ring. " "This is the part that is incorporated into Equation 1A." 7. The condensed ring compound according to claim 6, wherein, Equation 1A is represented by any one of Equations 1A-1 to 1A-5: Formula 1A-1 Formula 1A-2 Formula 1A-3 Formula 1A-4 Formula 1A-5 ,and Among them, in equations 1A-1 to 1A-5, Ar1, Ar2, d to g and R4 to R8 are all independently identical to those defined in Equation 1A, and HAr1 to HAr3 are all independently identical to those defined in Equation 2.

8. The condensed ring compound according to claim 6, wherein, Equation 2 is represented by any one of Equations 2-A to 2-J: ,and In Equations 2-A to 2-J, Ar3, Ar4, Ra, and r are all independently identical to those defined in Equation 2.

9. The condensed ring compound according to claim 6, wherein, Ar1 to Ar4 are each independently an unsubstituted phenyl, a substituted or unsubstituted alkyl-substituted phenyl with 1 to 10 carbon atoms, or a phenyl substituted with a deuterium atom.

10. The condensed ring compound according to claim 1 or claim 6, wherein the condensed ring compound is selected from any one of the compounds represented by group 1: Compound group 1 。

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