Organic light-emitting compound and organic electroluminescent device using the same

Abstract

The present invention relates to a novel compound having excellent luminescence ability and an organic electroluminescent device with improved characteristics such as luminescence efficiency, driving voltage, and lifespan by including the same in one or more organic layers.

Description

Technology Field

[0001] The present invention relates to a novel organic compound that can be used as a material for an organic electroluminescent device and an organic electroluminescent device comprising the same. Background Technology

[0003] Recently, there has been active development of organic electroluminescence displays as image display devices. Unlike liquid crystal displays, organic electroluminescence displays are so-called self-emissive display devices that realize a display by causing a light-emitting material containing an organic compound in the light-emitting layer to emit light by recombining holes and electrons injected from a first electrode and a second electrode in the light-emitting layer.

[0004] In applying organic light-emitting diodes to display devices, there is a demand for lower driving voltage, higher luminous efficiency, and longer lifespan of the devices, and there is a continuous demand for the development of materials for organic light-emitting diodes that can stably realize these requirements.

[0005] In particular, recently, to realize high-efficiency organic electroluminescent devices, technologies for phosphorescent emission using triplet energy or delayed fluorescence emission using the phenomenon of triplet-triplet annihilation (TTA), in which a singlet exciton is generated by the collision of a triplet exciton, are being developed, and the development of thermally activated delayed fluorescence (TADF) materials using the delayed fluorescence phenomenon is underway. Prior art literature

[0007] Republic of Korea Published Patent Application No. 10-2020-0142220 (Date of Publication: Dec. 22, 2020) The problem to be solved

[0008] The object of the present invention is to provide a long-life, high-efficiency organic electroluminescent device and a compound used therein.

[0009] Another objective of the present invention is to provide an organic electroluminescent device comprising a thermally active delayed fluorescent emitting material and a compound used as a thermally active delayed fluorescent emitting material. means of solving the problem

[0011] To achieve the above objective, the present invention provides a compound represented by the following chemical formula 1.

[0012] [Chemical Formula 1]

[0013]

[0014] In the above chemical formula 1,

[0015] A1 to A4, R1 to R 14 C1~C each independently 30 Alkyl group, C3~C 30 Cycloalkyl group, C1~C 60 Alkoxy group, C1~C 10 Thioalkoxy group, carbonyl group, carboxyl group, nitro group, cyano group, amine group, C6~C 30 Arylamine group, C3~C 30 Heteroaryl group, C5~C 60 monocyclic aryl group, C6~C 60 Condensed ring aryl group, C6~C 60 aryloxy group, C5~C 60 monocyclic heteroaryl group and C5~C 60 It is selected from the group consisting of condensed ring heteroaryl groups, and can form a condensed ring by combining with an adjacent group, and

[0016] Y1 to Y3 are each independently N or C(R 15 )(R 16 Selected from ), but at least one of them is N, and

[0017] R 15 and R 16 Each independently consists of hydrogen, C1~C 10 Alkyl group, C3~C10 Cycloalkyl group, C1~C 10 Alkoxy group, halogen group, cyano group, nitro group, hydroxyl group, C1~C 10 Silyl group, amino group, C6~C 30 arylamino group, C3~C 30 Heteroarylamino group, C6~C 30 Aryl group and C3~C 30 It is selected from a group consisting of heteroaryl groups and can mutually combine with adjacent groups to form a condensed ring,

[0018] Ring D is a group fused to a six-membered ring structure containing Y1 and Y2, C6-C 60 Monocyclic aryl group, C6-C 60 Condensed ring aryl group, C6-C 60 aryloxy group, C5~C 60 monocyclic heteroaryl group, C5~C 60 Selected from the group consisting of condensed ring heteroaryls, and

[0019] The above alkyl group, cycloalkyl group, alkoxy group, thioalkoxy group, arylamine group, heteroaryl group, monocyclic aryl group, condensed ring aryl group, aryloxy group, monocyclic heteroaryl group, or condensed heteroaryl group are each independently deuterium, halogen, cyano group, nitro group, C1~C 40 alkyl group of, C2~C 40 alkenyl group, C2~C 40 alkynyl group, C6~C 60 aryl group, heteroaryl group with 5 to 60 nuclei, C6~C 60 aryloxy group of, C1~C 40 alkyloxy group of, C6~C 60 The arylamine group of, C3~C 40 cycloalkyl group, heterocycloalkyl group having 3 to 40 nuclei, C1~C 40 alkylsilyl group of, C1~C 40 alkylboron group of, C6~C 60 arylboron group of, C6~C 60 arylphosphanyl group of, C6~C 60The mono or diarylphosphinyl group and C6~C 60 It is substituted with one or more substituents selected from the group consisting of arylsilyl groups or is not substituted, and when it is substituted with multiple substituents, they are identical or different from each other.

[0021] Another present invention provides an organic electroluminescent device comprising: a first electrode; a hole transport region disposed on the first electrode; a light-emitting layer disposed on the hole transport region; an electron transport region disposed on the light-emitting layer; and a second electrode disposed on the electron transport region, wherein the light-emitting layer comprises a compound represented by Formula 1.

[0023] For reference, 'alkyl' in the present invention is a monovalent substituent derived from a straight-chain or branched-chain saturated hydrocarbon, examples thereof include methyl, ethyl, propyl, isobutyl, sec-butyl, pentyl, iso-amyl, hexyl, etc., but is not limited thereto.

[0024] In the present invention, 'alkenyl' is a monovalent substituent derived from a straight-chain or side-chain unsaturated hydrocarbon having 2 to 40 carbon atoms and having one or more carbon-carbon double bonds, examples thereof include vinyl, allyl, isopropenyl, 2-butenyl, etc., but is not limited thereto.

[0025] In the present invention, 'alkynyl' is a monovalent substituent derived from a straight-chain or side-chain unsaturated hydrocarbon having one or more carbon-carbon triple bonds, examples thereof include, but are not limited to, ethynyl and 2-propynyl.

[0026] In the present invention, 'aryl' refers to a monovalent substituent derived from an aromatic hydrocarbon, consisting of a single ring or a combination of two or more rings. Additionally, it may include a monovalent substituent in which two or more rings are condensed together, containing only carbon as a ring-forming atom (e.g., the number of carbon atoms may be 8 to 60), and the entire molecule having non-aromacity. Examples of such aryls include, but are not limited to, phenyl, naphthyl, phenanthryl, anthryl, and fluorenyl.

[0027] In the present invention, 'heteroaryl' refers to a monovalent substituent derived from a monoheterocyclic or polyheterocyclic aromatic hydrocarbon. In this case, one or more carbons in the ring, preferably 1 to 3 carbons, are substituted with heteroatoms selected from N, O, P, S, and Se. Additionally, it is interpreted to include a monovalent group in which two or more rings are simply penantated or condensed together, and, in addition to carbons, heteroatoms selected from N, O, P, S, and Se are included as ring-forming atoms, and the entire molecule has non-aromacity. Examples of such heteroaryls include 6-membered monocyclic rings such as pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, and triazinyl; Polycyclic rings such as phenoxathienyl, indolizinyl, indolyl, purinyl, quinolyl, benzothiazole, and carbazolyl; 2-furanyl, N-imidazolyl, 2-isoxazolyl, 2-pyridinyl, 2-pyrimidinyl, etc., but are not limited thereto.

[0028] In the present invention, 'aryloxy' is a monovalent substituent represented by RO-, where R means aryl. Examples of such aryloxy include, but are not limited to, phenyloxy, naphthyloxy, and diphenyloxy.

[0029] In the present invention, 'alkoxy' or 'alkyloxy' refers to a monovalent substituent represented by R'O-, where R' signifies alkyl and is interpreted as including a linear, branched, or cyclic structure. Examples of such alkyloxy include, but are not limited to, methoxy, ethoxy, n-propoxy, 1-propoxy, t-butoxy, n-butoxy, and pentoxy.

[0030] The number of carbon atoms in the amine group in the present invention is not particularly limited, but may be 1 or more and 30 or less. The amine group may include alkyl amine groups and aryl amine groups. Examples of amine groups include methylamine groups, dimethylamine groups, phenylamine groups, naphthylamine groups, 9-methyl-anthracenylamine groups, triphenylamine groups, etc., but are not limited to these.

[0031] In the present invention, 'arylamine' refers to an amine substituted with an aryl group.

[0032] In the present invention, 'cycloalkyl' refers to a monovalent substituent derived from a monocyclic or polycyclic non-aromatic hydrocarbon. Examples of such cycloalkyls include, but are not limited to, cyclopropyl, cyclopentyl, cyclohexyl, norbornyl, and adamantine.

[0033] In the present invention, 'heterocycloalkyl' refers to a monovalent substituent derived from a non-aromatic hydrocarbon, wherein one or more carbons of the ring, preferably 1 to 3 carbons, are substituted with heteroatoms such as N, O, S, or Se. Examples of such heterocycloalkyls include, but are not limited to, morpholine and piperazine.

[0034] In the present invention, 'alkylsilyl' means a silyl substituted with an alkyl group, and 'arylsilyl' means a silyl substituted with an aryl group.

[0035] In the present invention, 'condensed ring' or 'condensed ring' refers to a condensed aliphatic ring, a condensed aromatic ring, a condensed heteroaliphatic ring, a condensed heteroaromatic ring, or a combination thereof.

[0036] In this specification, "substituted or unsubstituted" may mean substituted or unsubstituted with one or more substituents selected from the group consisting of deuterium atoms, halogen atoms, cyano groups, nitro groups, amine groups, silyl groups, boron groups, phosphine oxide groups, phosphine sulfide groups, alkyl groups, alkenyl groups, aryl groups, and heterocyclic groups. Additionally, each of the substituents exemplified above may be substituted or unsubstituted. Effects of the invention

[0038] An organic electroluminescent device according to one embodiment of the present invention can achieve high efficiency and a long lifespan.

[0039] A compound according to one embodiment of the present invention can improve the lifespan and efficiency of an organic electroluminescent device. Specific details for implementing the invention

[0041] The present invention will be described in detail below.

[0042] 1. Novel organic compounds

[0043] The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0045] In one embodiment, the light-emitting layer (EML) comprises a compound represented by Chemical Formula 1.

[0046] [Chemical Formula 1]

[0047]

[0048] In the above Chemical Formula 1, A1 to A4, R1 to R 14 C1~C each independently 30 Alkyl group, C3~C 30 Cycloalkyl group, C1~C 60 Alkoxy group, C1~C 10 Thioalkoxy group, carbonyl group, carboxyl group, nitro group, cyano group, amine group, C6~C 30 Arylamine group, C3~C 30 Heteroaryl group, C5~C 60 monocyclic aryl group, C6~C 60 Condensed ring aryl group, C6~C 60 aryloxy group, C5~C 60 monocyclic heteroaryl group and C5~C 60 It is selected from the group consisting of condensed ring heteroaryl groups, and can form a condensed ring by combining with an adjacent group, and

[0049] Y1 to Y3 are each independently N or C(R 15 )(R 16 Selected from ), but at least one of them is N, and

[0050] R 15 and R 16 Each independently consists of hydrogen, C1~C 10 Alkyl group, C3~C 10 Cycloalkyl group, C1~C 10 Alkoxy group, halogen group, cyano group, nitro group, hydroxyl group, C1~C 10 Silyl group, amino group, C6~C 30 arylamino group, C3~C 30 Heteroarylamino group, C6~C 30 Aryl group and C3~C 30 It is selected from a group consisting of heteroaryl groups and can mutually combine with adjacent groups to form a condensed ring,

[0051] Ring D is a group fused to a six-membered ring structure containing Y1 and Y2, C6-C 60 Monocyclic aryl group, C6-C 60 Condensed ring aryl group, C6-C 60 aryloxy group, C5~C60 monocyclic heteroaryl group, C5~C 60 Selected from the group consisting of condensed ring heteroaryls, and

[0052] The above alkyl group, cycloalkyl group, alkoxy group, thioalkoxy group, arylamine group, heteroaryl group, monocyclic aryl group, condensed ring aryl group, aryloxy group, monocyclic heteroaryl group, or condensed heteroaryl group are each independently deuterium, halogen, cyano group, nitro group, C1~C 40 alkyl group of, C2~C 40 alkenyl group, C2~C 40 alkynyl group, C6~C 60 aryl group, heteroaryl group with 5 to 60 nuclei, C6~C 60 aryloxy group of, C1~C 40 alkyloxy group of, C6~C 60 The arylamine group of, C3~C 40 cycloalkyl group, heterocycloalkyl group having 3 to 40 nuclei, C1~C 40 alkylsilyl group of, C1~C 40 alkylboron group of, C6~C 60 arylboron group of, C6~C 60 arylphosphanyl group of, C6~C 60 The mono or diarylphosphinyl group and C6~C 60 It is substituted with one or more substituents selected from the group consisting of arylsilyl groups or is not substituted, and when it is substituted with multiple substituents, they are identical or different from each other.

[0053] The above ring D may be represented by the following chemical formula 2 or chemical formula 3.

[0054] [Chemical Formula 2]

[0055]

[0056] [Chemical Formula 3]

[0057]

[0058] In the above chemical formulas 2 and 3, the dotted line indicates the part where condensation takes place, and

[0059] m is an integer from 0 to 4; n is an integer from 0 to 6,

[0060] R 17 Silver consists of hydrogen, deuterium, halogen, cyano group, nitro group, C1~C 40 alkyl group of, C2~C 40 alkenyl group, C2~C 40 alkynyl group, C3~C 40 cycloalkyl group, heterocycloalkyl group having 3 to 40 nuclei, C6~C 60 aryl group, heteroaryl group with 5 to 60 nuclei, C1~C 40 alkyloxy group of, C6~C 60 The aryloxy group of, C3~C 40 alkylsilyl group of, C6~C 60 arylsilyl group of, C1~C 40 alkylboron group of, C6~C 60 arylboron group of, C6~C 60 arylphosphanyl group of, C6~C 60 The mono or diarylphosphinyl group and C6~C 60 Selected from the group consisting of an arylamine group, and the R 13 In the case of multiple individuals, they are identical or different from each other,

[0061] The above R 17 The alkyl group, alkenyl group, alkynyl group, aryl group, heteroaryl group, aryloxy group, alkyloxy group, cycloalkyl group, heterocycloalkyl group, arylamine group, alkylsilyl group, alkylboron group, arylboron group, arylphosphanyl group, mono- or diarylphosphinyl group, and arylsilyl group are each independently deuterium, halogen, cyano group, nitro group, C1~C 40 alkyl group of, C2~C 40 alkenyl group, C2~C 40 alkynyl group, C6~C 60 aryl group, heteroaryl group with 5 to 60 nuclei, C6~C 60 aryloxy group of, C1~C 40 alkyloxy group of, C6~C 60The arylamine group of, C3~C 40 cycloalkyl group, heterocycloalkyl group having 3 to 40 nuclei, C1~C 40 alkylsilyl group of, C1~C 40 alkylboron group of, C6~C 60 arylboron group of, C6~C 60 arylphosphanyl group of, C6~C 60 The mono or diarylphosphinyl group and C6~C 60 It may be substituted with one or more substituents selected from the group consisting of arylsilyl groups, or unsubstituted, and when substituted with multiple substituents, these may be identical or different from each other.

[0062] The above A1 to A4 are each independently substituted or unsubstituted C1~ C30 It may be selected from the group consisting of alkyl groups, substituted or unsubstituted phenyl groups, substituted or unsubstituted naphthyl groups, and substituted or unsubstituted pyridyl groups.

[0063] When the above adjacent pairs of A1 and A2 or A3 and A4 each combine with one another to form a condensation ring, a condensation ring selected from the group consisting of A-1 to A-4 below can be formed.

[0064]

[0065] Here, * indicates the part where the combination takes place.

[0066] A compound according to one embodiment of the present invention may be selected from the group consisting of the following compounds.

[0067]

[0068] 2. Organic Electroluminescent Devices

[0069] Hereinafter, an organic electroluminescent device according to one embodiment of the present invention will be described.

[0070] An organic electroluminescent device according to one embodiment may include a first electrode (EL1), a hole transport region (HTR), an emitting layer (EML), an electron transport region (ETR), and a second electrode (EL2) that are sequentially stacked. The first electrode (EL1) and the second electrode (EL2) are arranged facing each other, and a plurality of organic layers may be arranged between the first electrode (EL1) and the second electrode (EL2). The plurality of organic layers may include a hole transport region (HTR), an emitting layer (EML), and an electron transport region (ETR). The organic electroluminescent device of one embodiment may include a compound of one embodiment according to the present invention described above in the emitting layer (EML).

[0071] In an organic electroluminescent device of one embodiment, the first electrode (EL1) is conductive. The first electrode (EL1) may be formed of a metal alloy or a conductive compound. The first electrode (EL1) may be an anode. The first electrode (EL1) may be a transmissive electrode, a semitransmissive electrode, or a reflective electrode. If the first electrode (EL1) is a transmissive electrode, the first electrode (EL1) may be made of a transparent metal oxide, for example, ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), ITZO (indium tin zinc oxide), etc. When the first electrode (EL1) is a semi-transparent electrode or a reflective electrode, the first electrode (EL1) may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or compounds or mixtures thereof (e.g., a mixture of Ag and Mg). Alternatively, it may be a plurality of layer structures including a reflective film or a semi-transparent film formed of the materials exemplified above and a transparent conductive film formed of ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), ITZO (indium tin zinc oxide), etc. For example, the first electrode (EL1) may include a plurality of ITO / Ag / ITO layers.

[0072] A hole transport region (HTR) is provided on the first electrode (EL1). The hole transport region (HTR) may include at least one of a hole injection layer (HIL), a hole transport layer (HTL), a hole buffer layer, and an electron blocking layer (EBL). The hole transport region (HTR) may have a multilayer structure having a single layer made of a single material, a single layer made of a plurality of different materials, or a plurality of layers made of a plurality of different materials.

[0073] For example, the hole transport region (HTR) may have a single-layer structure of a hole injection layer (HIL) or a hole transport layer (HTL), or it may have a single-layer structure composed of a hole injection material and a hole transport material. Additionally, the hole transport region (HTR) may have a single-layer structure composed of multiple different materials, or it may have a structure of a hole injection layer (HIL) / hole transport layer (HTL), a hole injection layer (HIL) / hole transport layer (HTL) / hole buffer layer, a hole injection layer (HIL) / hole buffer layer, a hole transport layer (HTL) / hole buffer layer, or a hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) stacked sequentially from the first electrode (EL1), but the embodiments are not limited thereto.

[0074] Hole transport regions (HTRs) can be formed using various methods such as vacuum deposition, spin coating, casting, LB method (Langmuir-Blodgett), inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0075] The hole injection layer (HIL) of an organic electroluminescent device of one embodiment may include a known hole injection material. For example, the hole injection layer (HIL) is a phthalocyanine compound such as triphenylamine-containing polyetherketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate (PPBI), N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-phenyl-4,4'-diamine (DNTPD), and copper phthalocyanine, 4,4',4''-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB), N,N'-bis(1-naphthyl)-N,N'-diphenyl-4,4'-diamine (α-NPD), and 4,4',4''-tris{N,N diphenylamino}triphenylamine (TDATA). It may include 4,4',4''-tris(N,N-2-naphthylphenylamino)triphenylamine (2-TNATA), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / campersulfonic acid (PANI / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), or HAT-CN (dipyrazino[2,3-f: 2',3'-h] quinoxaline-2,3,6,7,10,11-hexacarbonitrile), etc. However, the examples are not limited thereto.

[0076] The hole transport layer (HTL) of an organic electroluminescent device of one embodiment may include a known hole transport material. For example, the hole transport layer (HTL) may include carbazole derivatives such as 1,1-bis[(di-4-trilamino)phenyl]cyclohexane (TAPC), N-phenylcarbazole, and polyvinylcarbazole, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD), 4,4',4''-tris(N-carbazolyl)triphenylamine (TCTA), or N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB), N,N'-bis(1-naphthyl)-N,N'-diphenyl-4,4'-diamine (α-NPD), etc. However, the embodiments are not limited thereto. Meanwhile, the hole transport region (HTR) further includes an electron blocking layer (EBL), and the electron blocking layer (EBL) may be disposed between the hole transport layer (HTL) and the light-emitting layer (EML). The electron blocking layer (EBL) is a layer that serves to prevent electron injection from the electron transport region (ETR) into the hole transport region (HTR).

[0077] The electronic blocking layer (EBL) may include common materials known in the art. The electron blocking layer (EBL) may include, for example, carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, fluorine derivatives, triphenylamine derivatives such as TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine) and TCTA (4,4',4"-tris(Ncarbazolyl)triphenylamine), NPD (N,N'-di(naphthalene-l-yl)-N,N'-diplienyl-benzidine), TAPC (4,4'-Cyclohexylidene bis[N,N-bis(4-methylphenyl)benzenamine]), HMTPD (4,4'-Bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl), or mCP, etc. In addition, as described above, the electron The blocking layer (EBL) may include a compound according to one embodiment of the present invention.

[0078] The thickness of the hole transport region (HTR) may be about 100 Å to about 10,000 Å, for example, about 100 Å to about 5,000 Å. The thickness of the hole injection layer (HIL) may be, for example, about 30 Å to about 1,000 Å, and the thickness of the hole transport layer (HTL) may be about 30 Å to about 1,000 Å. For example, the thickness of the electron blocking layer (EBL) may be about 10 Å to about 1,000 Å. When the thicknesses of the hole transport region (HTR), the hole injection layer (HIL), the hole transport layer (HTL), and the electron blocking layer (EBL) satisfy the ranges described above, satisfactory hole transport characteristics can be obtained without a substantial increase in driving voltage.

[0079] In addition to the aforementioned materials, the hole transport region (HTR) may further include a charge-generating material to enhance conductivity. The charge-generating material may be uniformly or non-uniformly dispersed within the hole transport region (HTR). The charge-generating material may be, for example, a p-dopant. The p-dopant may be one of quinone derivatives, metal oxides, and cyano group-containing compounds, but is not limited thereto. For example, non-limiting examples of p-dopants include quinone derivatives such as TCNQ (Tetracyanoquinodimethane) and F4-TCNQ (2,3,5,6-tetrafluoro-tetracyanoquinodimethane), metal oxides such as tungsten oxide and molybdenum oxide, but are not limited thereto.

[0080] As previously mentioned, the hole transport region (HTR) may further include at least one of a hole buffer layer and an electron blocking layer (EBL) in addition to the hole injection layer (HIL) and the hole transport layer (

[0064] HTL). The hole buffer layer can increase light emission efficiency by compensating for the resonance distance according to the wavelength of light emitted from the light-emitting layer (EML). The material included in the hole buffer layer may be a material that can be included in the hole transport region (HTR).

[0081] An emissive layer (EML) is provided on a hole transport region (HTR). The thickness of the emissive layer (EML) may be, for example, about 100 Å or more and 600 Å or less. The emissive layer (EML) may have a single layer made of a single material, a single layer made of multiple different materials, or a multilayer structure having multiple layers made of multiple different materials.

[0082] The light-emitting layer (EML) may emit one of red light, green light, blue light, white light, yellow light, or cyan light. The light-emitting layer (EML) may include a fluorescent light-emitting material or a phosphorescent light-emitting material.

[0083] In one embodiment, the emitting layer (EML) may be a fluorescent emitting layer. For example, some of the light emitted from the emitting layer (EML) may be due to thermally activated delayed fluorescence (TADF). Specifically, the emitting layer (EML) may include a emitting component that emits thermally activated delayed fluorescence, and in one embodiment, the emitting layer (EML) may be a thermally activated delayed fluorescence emitting layer that emits green light or red light.

[0085] [Preparation Example]

[0086] The present invention will be explained in more detail below through specific embodiments and comparative examples. The following embodiments are merely examples to aid in understanding the present invention and do not limit the scope of the present invention.

[0088] [Preparation Example 1]

[0089] 1.1. Synthesis of 10,10'-(5-bromo-2-chloro-1,3-phenylene)bis(9,9-diphenyl-9,10-dihydroacridine)

[0090]

[0091] Under a nitrogen stream, 5-bromo-2-chloro-1,3-difluorobenzene (40.0 g, 17 mmol), 9,9-diphenyl-9,10-dihydroacridine (14.6 g, 43.9 mmol), and Cs2CO3 (27.6 g, 85 mmol) were mixed with 300 ml of DMF and stirred at 155°C for 12 hours. When the reaction was complete, water was added to terminate the reaction, and 12.3% (85%) of the target compound was obtained by recrystallization.

[0092] GC-Mass (Theoretical value: 852.19 g / mol, Measured value: 854.29 g / mol)

[0093] 1H-NMR: δ 7.26~7.18 (m, 16H), 6.95 (m, 4H), 6.82 (s, 2H)

[0095] 1.2. Synthesis of 10,10'-(4-chloro-2'-isocyano-[1,1'-biphenyl]-3,5-diyl)bis(9,9-diphenyl-9,10-dihydroacridine)

[0096]

[0097] Under a nitrogen stream, 1-1 (12.3g, 10.5mmol), (2-isocyanophenyl)boronic acid (1.7g, 11.6mmol), Pd(PPh3)4 (0.21g, mmol), and K2CO3 (3.62g, 26.25mmol) were mixed with 100ml of THF / H2O and stirred at 155℃ for 12 hours. When the reaction was complete, water was added to terminate the reaction, and 7g (77%) of the target compound was obtained by recrystallization.

[0098] GC-Mass (Theoretical value: 875.31 g / mol, Measured value: 876.50 g / mol)

[0099] 1H-NMR: δ 7.77(dd, 1H), 7.52~7.45(m, 3H), 7.26~7.14(m, 16H), 6.95(m, 4H), 6.87(s, 2H)

[0101] [Preparation Example 2]

[0102] Synthesis of 10,10'-(4-chloro-2'-isocyano-[1,1'-biphenyl]-3,5-diyl)bis(9-methyl-9-phenyl-9,10-dihydroacridine)

[0103] 6.2 g of the target compound was obtained by performing the same process as in [Preparation Example 1], except that 9-methyl-9-phenyl-9,10-dihydroacridine was used as the reactant.

[0104] GC-Mass (Theoretical value: 751.28 g / mol, Measured value: 752.36 g / mol)

[0106] [Preparation Example 3]

[0107] Synthesis of 10,10'-(4-chloro-2'-isocyano-[1,1'-biphenyl]-3,5-diyl)bis(9-phenyl-9-(pyridin-3-yl)-9,10-dihydroacridine)

[0108] 7.2 g of the target compound was obtained by performing the same process as in [Preparation Example 1], except that 9-phenyl-9-(pyridin-3-yl)-9,10-dihydroacridine was used as the reactant.

[0109] GC-Mass (Theoretical value: 877.30 g / mol, Measured value: 878.48 g / mol)

[0111] [Preparation Example 4]

[0112] Synthesis of 10,10''-(4-chloro-2'-isocyano-[1,1'-biphenyl]-3,5-diyl)bis(10H-spiro[acridine-9,9'-fluorene])

[0113] 7.1 g of the target compound was obtained by performing the same process as in [Preparation Example 1], except that 10H-spiro[acridine-9,9'-fluorene] was used as the reactant.

[0114] GC-Mass (Theoretical value: 871.28 g / mol, Measured value: 872.47 g / mol)

[0116] [Preparation Example 5]

[0117] Synthesis of 10,10'-(4-chloro-2'-isocyano-[1,1'-biphenyl]-3,5-diyl)bis(9,9-di(naphthalen-2-yl)-9,10-dihydroacridine)

[0118] 8.2 g of the target compound was obtained by performing the same process as in [Preparation Example 1], except that 9,9-di(naphthalen-2-yl)-9,10-dihydroacridine was used as the reactant.

[0119] GC-Mass (Theoretical value: 1075.37 g / mol, Measured value: 1076.74 g / mol)

[0121] [Preparation Example 6]

[0122] Synthesis of 10,10''-(4-chloro-2'-isocyano-[1,1'-biphenyl]-3,5-diyl)bis(10H-spiro[acridine-9,1'-cyclopentane])

[0123] 5.7 g of the target compound was obtained by performing the same process as in [Preparation Example 1], except that 10H-spiro[acridine-9,1'-cyclopentane] was used as the reactant.

[0124] GC-Mass (Theoretical value: 679.28 g / mol, Measured value: 680.29 g / mol)

[0126] [Preparation Example 7]

[0127] Synthesis of 10,10''-(4-chloro-2'-isocyano-[1,1'-biphenyl]-3,5-diyl)bis(10H-spiro[acridine-9,1'-cyclohexane])

[0128] 5.9 g of the target compound was obtained by performing the same process as in [Preparation Example 1], except that 10H-spiro[acridine-9,1'-cyclohexane] was used as the reactant.

[0129] GC-Mass (Theoretical value: 707.31 g / mol, Measured value: 708.35 g / mol)

[0131] [Preparation Example 8]

[0132] Synthesis of 10-(4-chloro-2'-isocyano-5-(10H-spiro[acridine-9,2'-adamantan]-10-yl)-[1,1'-biphenyl]-3-yl)-10H-spiro[acridine-9,2'-adamantane]

[0133] 6.9 g of the target compound was obtained by performing the same process as in [Preparation Example 1], except that (1'r,3'r,5'r,7'r)-10H-spiro[acridine-9,2'-adamantane] was used as the reactant.

[0134] GC-Mass (Theoretical value: 811.37 g / mol, Measured value: 812.50 g / mol)

[0136] [Synthesis Example 1] Synthesis of Mat 1

[0137]

[0138] Under a nitrogen stream, n-butyllithium (3.65 ml, 8.778 mmol) was slowly added dropwise to 100 ml of t-butylbenzene solution (7 g, 7.98 mmol) at 0°C and stirred for 30 minutes. After stirring, the temperature was raised to 60°C and stirred for 2 hours. The temperature was lowered to -40°C, Tribromide (2 g, 7.98 mmol) was slowly added dropwise, and the temperature was raised to room temperature. After stirring at room temperature for 30 minutes, the temperature was lowered to 0°C, and N,N-Diisopropylethylamine (1.65 g, 12.7 mmol) was slowly added dropwise. The temperature was slowly raised to room temperature. The mixture was stirred at 120°C for 5 hours. When the reaction was complete, the temperature was lowered to room temperature and the reaction was terminated with a sodium acetate dichloromethane solution. The mixture was extracted with 500 mL of MC and washed with distilled water. The obtained organic layer was dried with anhydrous MgSO4, subjected to vacuum distillation, and purified by silica gel column chromatography to obtain 3.72 g of the target compound (yield 50%).

[0139] GC-Mass (Theoretical value: 905.39 g / mol, Measured value: 905.95 g / mol)

[0140] 1H-NMR: δ 7.92(d, 1H), 7.83(d, 1H), 7.68(t, 1H), 7.51(t, 1H), 7.26~7.10(m, 16H), 6.95(m, 4H), 6.25(s, 1H), 2.77(t, 2H), 1.62(t, 2H), 1.33(t, 1H), 1.60(t, 3H)

[0142] [Synthesis Example 2] Synthesis of Mat 2

[0143] 2.5 g of the target compound was obtained by performing the same process as in [Synthesization Example 1], except that [Preparation Example 2] was used as the reactant. HRMS [M]+: 783.81

[0145] [Synthesis Example 3] Synthesis of Mat 3

[0146] 2.9 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that [Preparation Example 3] was used as the reactant. HRMS [M]+: 908.93

[0148] [Synthesis Example 4] Synthesis of Mat 4

[0149] 3.1 g of the target compound was obtained by performing the same process as in [Synthesization Example 1], except that [Preparation Example 4] was used as the reactant. HRMS [M]+: 902.92

[0151] [Synthesis Example 5] Synthesis of Mat 5

[0152] 3.2 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that [Preparation Example 5] was used as the reactant. HRMS [M]+: 1107.19

[0154] [Synthesization Example 6] Synthesis of Mat 6

[0155] 2.4 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that [Preparation Example 6] was used as the reactant. HRMS [M]+: 710.74

[0157] [Synthesis Example 7] Synthesis of Mat 7

[0158] 2.8 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that [Preparation Example 7] was used as the reactant. HRMS [M]+: 738.80

[0160] [Synthesization Example 8] Synthesis of Mat 8

[0161] 3.6 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that [Preparation Example 8] was used as the reactant. HRMS [M]+: 842.94

[0163] [Synthesization Example 9] Synthesis of Mat 9

[0164] 3.1 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that tert-butyllithium was used as the reactant. HRMS [M]+: 906.95

[0166] [Synthesization Example 10] Synthesis of Mat 10

[0167] 2.6 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that tert-butyllithium was used as the reactant. HRMS [M]+: 782.81

[0169] [Synthesization Example 11] Synthesis of Mat 11

[0170] 3.0 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that tert-butyllithium was used as the reactant. HRMS [M]+: 908.92

[0172] [Synthesization Example 12] Synthesis of Mat 12

[0173] 2.8 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that tert-butyllithium was used as the reactant. HRMS [M]+: 902.92

[0175] [Synthesization Example 13] Synthesis of Mat 13

[0176] 3.0 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that tert-butyllithium was used as the reactant. HRMS [M]+: 1107.19

[0178] [Synthesization Example 14] Synthesis of Mat 14

[0179] 2.5 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that tert-butyllithium was used as the reactant. HRMS [M]+: 710.74

[0181] [Synthesization Example 15] Synthesis of Mat 15

[0182] 2.8 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that tert-butyllithium was used as the reactant. HRMS [M]+: 738.80

[0184] [Synthesization Example 16] Synthesis of Mat 16

[0185] 3.2 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that tert-butyllithium was used as the reactant. HRMS [M]+: 842.95

[0187] [Synthesization Example 17] Synthesis of Mat 17

[0188] 3.4 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that phenyllithium was used as the reactant. HRMS [M]+: 926.94

[0190] [Synthesization Example 18] Synthesis of Mat 18

[0191] 2.7 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that phenyllithium was used as the reactant. HRMS [M]+: 802.80

[0193] [Synthesization Example 19] Synthesis of Mat 19

[0194] 3.0 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that phenyllithium was used as the reactant. HRMS [M]+: 928.932

[0196] [Synthesization Example 20] Synthesis of Mat 20

[0197] 3.0 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that phenyllithium was used as the reactant. HRMS [M]+: 922.91

[0199] [Synthesization Example 21] Synthesis of Mat 21

[0200] 3.2 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that phenyllithium was used as the reactant. HRMS [M]+: 1127.18

[0202] [Synthesization Example 22] Synthesis of Mat 22

[0203] 2.7 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that phenyllithium was used as the reactant. HRMS [M]+: 730.73

[0205] [Synthesization Example 23] Synthesis of Mat 23

[0206] 3.0 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that phenyllithium was used as the reactant. HRMS [M]+: 758.79

[0208] [Synthesization Example 24] Synthesis of Mat 24

[0209] 3.0 g of the target compound was obtained by performing the same procedure as in [Synthesization Example 1], except that phenyllithium was used as the reactant. HRMS [M]+: 862.94

[0211] [Examples 1–13] Preparation of Green Organic EL Devices

[0212] The compound synthesized in the above synthesis example was purified by high-purity sublimation using a commonly known method, and then a green organic EL device was fabricated according to the following process.

[0213] First, a glass substrate coated with a thin film of ITO (Indium tin oxide) to a thickness of 1500 Å was cleaned with distilled water ultrasonics. After the distilled water cleaning was finished, the substrate was ultrasonically cleaned with solvents such as isopropyl alcohol, acetone, and ethanol, dried, transferred to a UV OZONE cleaner (Power sonic 405, Hwashin Tech), cleaned with UV light for 5 minutes, and then transferred to a vacuum deposition machine.

[0214] A hole injection layer was formed with a thickness of 80 nm using DS-205 (Doosan) on the prepared ITO transparent electrode, and a hole transport layer was formed by vacuum deposition of α-NPB (N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine) with a thickness of 30 nm on the hole transport layer.

[0215] On top of that, compounds prepared in Synthesis Example 1 to 24 as green dopant materials and DS-H522 and DS-TD-002 as green light-emitting host materials were applied as common hosts to form a light-emitting layer with a thickness of 30 nm. At this time, the doping ratio of the light-emitting layer was applied uniformly as (DS-H522:DS-TD-002:Synthesis Example 1 to 24 = 75%:20%:5%).

[0216] An electron transport layer was formed on the above-mentioned light-emitting layer using TPBi (2,2′,2"-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole)), an electron transport material, with a thickness of 30 nm. Then, an electron injection layer of LiF with a thickness of 1 nm was formed, and a device was fabricated by forming 200 nm of Al as the cathode.

[0218] [Comparative Example]

[0219] Organic electroluminescent devices were fabricated using the same method as the above device fabrication example, except that Alq3, C-545T and Comparative Example 1, which are representative green light-emitting materials, were used, and the evaluation results of the fabricated devices are listed in Table 1.

[0220]

[0222] [Evaluation Example]

[0223] For each organic EL device fabricated in Examples 1 to 13 and Comparative Examples 1 to 3, the driving voltage, current efficiency, and luminescence peak at a current density of 10 mA / cm² were measured, and the results are shown in Table 1 below.

[0224] Sample green dopant Driving voltage EL peak Current efficiency (V) (nm) (cd / A) Example 1 Mat1 5.88 531 21.3 Example 2 Mat2 5.19 537 23.1 Example 3 Mat4 5.04 535 25.1 Example 4 Mat7 5.7 536 21.4 Example 5 Mat8 5.72 538 24.5 Example 6 Mat9 5.22 531 21.3 Example 7 Mat12 5.01 537 23.1 Example 8 Mat15 5.18 535 25.1 Example 9 Mat16 5.06 536 21.4 Example 10 Mat17 5.88 538 26.7 Example 11 Mat20 5.19 537 26.9 Example 12 Mat23 5.04 541 26.3 Example 13 Mat24 5.66 529 18.0 Comparative Example 1 Comparative Example 1 6.52 515 14.9 Comparative Example 2 C-545T 5.90 518 15.5 Comparative Example 3 Alq3 6.14 525 12.8

[0226] From Table 1 above, it can be confirmed that the driving voltage, emission peak, and current efficiency of the organic light-emitting devices prepared in Examples 1 to 13 are superior to those of the organic light-emitting devices prepared in Comparative Examples 1, 2, and 3, respectively, due to the rigid chemical structure and the structure favorable for exciton formation within the light-emitting layer.

[0228] [Examples 14–19] Preparation of Red Organic EL Devices

[0229] The compound synthesized in the above synthesis example was purified by high-purity sublimation using a commonly known method, and then a red organic EL device was fabricated according to the following process.

[0230] First, a glass substrate coated with a thin film of ITO (Indium tin oxide) to a thickness of 1500 Å was cleaned with distilled water ultrasonics. After the distilled water cleaning was finished, the substrate was ultrasonically cleaned with solvents such as isopropyl alcohol, acetone, and ethanol, dried, transferred to a UV OZONE cleaner (Power sonic 405, Hwashin Tech), cleaned with UV light for 5 minutes, and then transferred to a vacuum deposition machine.

[0231] A hole injection layer was formed with a thickness of 80 nm using DS-205 (Doosan) on the prepared ITO transparent electrode, and a hole transport layer was formed by vacuum deposition of α-NPB (N,N′-Di(1-naphthyl)-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine) with a thickness of 30 nm on the hole transport layer.

[0232] On top of that, compounds prepared in Synthesis Example 3 to 21 as red dopant materials and DS-H522 and DS-TD-018 as red light-emitting host materials were applied as common hosts to form a light-emitting layer with a thickness of 30 nm. At this time, the doping ratio of the light-emitting layer was applied uniformly as (DS-H522:DS-TD-018:Synthesis Example 3 to 21 = 75%:20%:5%).

[0233] An electron transport layer was formed on the above-mentioned light-emitting layer using TPBi (2,2′,2"-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole)), an electron transport material, with a thickness of 30 nm. Then, an electron injection layer of LiF with a thickness of 1 nm was formed, and a device was fabricated by forming 200 nm of Al as the cathode.

[0235] [Comparative Example]

[0236] Organic electroluminescent devices were fabricated using the same method as the above device fabrication example, except that DCM2, DCJTB, and DCDDC, which are representative red light-emitting materials, were used, and the evaluation results of the fabricated devices are listed in Table 2.

[0237] Sample red dopant Driving voltage EL peak Current efficiency (V) (nm) (cd / A) Example 14 Mat 3 5.92 620 24.1 Example 15 Mat 5 5.97 620 23.8 Example 16 Mat 11 5.85 618 20.8 Example 17 Mat 13 5.91 618 23.2 Example 18 Mat 19 5.88 619 22.5 Example 19 Mat 21 5.81 620 18.3 Comparative Example 4 DCDDC 6.12 620 18.3 Comparative Example 5 DCM2 5.76 623 17.7 Comparative Example 6 DCJTB 6.32 628 17.1

[0238] From Table 2 above, it was confirmed that the driving voltage, emission peak, and current efficiency of the organic light-emitting devices prepared in Examples 14 to 19 were superior to those of the organic light-emitting devices prepared in Comparative Examples 4, 5, and 6, respectively, due to the rigid chemical structure and the structure favorable for exciton formation within the light-emitting layer.

Claims

Claim 1 Compound represented by the following chemical formula 1: [Chemical Formula 1] In the above chemical formula 1, A1 to A4 each form a condensed ring selected from the group consisting of A-1 to A-4 by mutually combining adjacent pairs of A1 and A2 or A3 and A4. In the above chemical formulas A-1 to A-4, * indicates the part where the bond is formed, and R1 to R 14 is hydrogen, Y1 is N, and Y2 and Y3 are independently C(R 15 Selected from ), R 15 Each independently consists of hydrogen, C1~C 10 Alkyl group, C6~C 30 Selected from the group consisting of aryl groups, ring D is represented by the following chemical formula 2, [Chemical Formula 2] In the above chemical formula 2, the dotted line indicates the region where condensation takes place; m is an integer from 0 to 4; and R 17 Each is independently hydrogen or deuterium. Claim 2 In claim 1, the compound is characterized by being selected from the group consisting of the following compounds: Claim 3 A compound characterized by being selected from the group consisting of the following compounds: Claim 4 An organic electroluminescent device comprising: a first electrode; a hole transport region disposed on the first electrode; a light-emitting layer disposed on the hole transport region; an electron transport region disposed on the light-emitting layer; and a second electrode disposed on the electron transport region, wherein the light-emitting layer comprises a compound represented by Formula 1 according to Claim 1 or a compound of Claim 3. Claim 5 In claim 4, the light-emitting layer is an organic electroluminescent device that emits delayed fluorescence. Claim 6 In claim 4, the light-emitting layer is a delayed fluorescent light-emitting layer comprising a host and a dopant, and the dopant is an organic electroluminescent device that is the compound. Claim 7 In claim 4, the above-mentioned light-emitting layer is an organic electroluminescent device that is a thermally active delayed fluorescent light-emitting layer emitting blue light. Claim 8 delete Claim 9 delete

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