Novel compound and organic light-emitting device comprising same

Abstract

The present invention provides a novel compound which can be applied to at least one of an electron injection layer (EIL), an electron transport layer (ETL), a hole blocking layer (HBL), a layer which simultaneously injects and transports electrons, and a charge generation layer (CGL), and an organic light-emitting device comprising the novel compound.

Description

Novel compound and organic light-emitting device containing the same

[0001] The present invention relates to a novel compound and an organic light-emitting device containing the same.

[0002] The technology of organic light-emitting devices (or organic light-emitting diodes), which are one of the widely used flat panel display devices today, is rapidly advancing.

[0003] Generally, an organic light-emitting diode (OLED) comprises an organic thin film layer including a light-emitting layer formed between an anode (hole injection electrode) and a cathode (electron injection electrode), and emits light based on the principle that holes injected from the anode and electrons injected from the cathode pair up in the light-emitting layer and then annihilate each other.

[0004] More specifically, the organic light-emitting device is configured to include an organic thin film layer formed between an anode and a cathode, and the organic thin film layer may be configured to include a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer sequentially stacked on the anode, wherein holes injected from the anode and electrons injected from the cathode combine in the light-emitting layer to form excitons, which become an unstable energy state (excited state) and then return to a stable ground state to emit light.

[0005] Meanwhile, as the development of high-performance organic light-emitting diodes is increasingly required, there is a need to develop new materials capable of exhibiting superior performance.

[0006] The present invention aims to provide an organic light-emitting diode capable of realizing low voltage, high efficiency, and long lifespan when the novel compound is applied to one or more organic layers among the electron transport layer (ETL), hole blocking layer (HBL), and N-type charge generation layer (N-CGL) of the organic layer of the organic light-emitting diode.

[0007] The above tasks and additional tasks are described in detail below.

[0008] In order to solve the problem described above, the present invention provides, in one embodiment, a novel compound represented by the following chemical formula 1.

[0009] <Chemical Formula 1>

[0010]

[0011] In the above chemical formula 1,

[0012] L1 and L2 are each independently directly bonded, substituted, or unsubstituted C6~C 30 The arylene group, or substituted or unsubstituted C2~C 30 It is a heteroarylene group, and

[0013] a and b are each independently integers from 0 to 3, and

[0014] Among the above Ar1 and the above Ar2, one is the following structural formula A and the other is the following structural formula B, and

[0015] <Structural Formula A>

[0016]

[0017] <Structural Formula B>

[0018]

[0019] In the above structural formulas A and B,

[0020] R is independently hydrogen, deuterium, halogen, cyano group, nitro group, nitrile group, or substituted or unsubstituted C1~C 30 alkyl groups, substituted or unsubstituted C1~C 30 alkenyl groups, substituted or unsubstituted C1~C 30 alkynyl groups, substituted or unsubstituted C3~C 30 cycloalkyl groups, substituted or unsubstituted C1~C 30 heterocycloalkyl groups, substituted or unsubstituted C1~C 30 alkoxy groups, substituted or unsubstituted C1~C30 sulfide groups, substituted or unsubstituted C6~C 30 aryl groups, substituted or unsubstituted C2~C 30 heteroaryl groups, substituted or unsubstituted C6~C 30 The aryloxy group of, substituted or unsubstituted C2~C 30 heteroaryloxy groups of, substituted or unsubstituted C1~C 30 thiogroups, substituted or unsubstituted C1~C 30 amine groups, substituted or unsubstituted C1~C 30 The silyl group and substituted or unsubstituted C1~C 30 Selected from the group consisting of phosphine oxide groups, wherein adjacent ones may or may not combine to form a substituted or unsubstituted ring, and

[0021] n is an integer from 0 to 7, and

[0022] X is independently either N or CH, and

[0023] Y1 to Y3 are each independently N or CH, provided that at least one is N, and

[0024] Z1 to Z3 are each independently N or CH, and at least one is N, and

[0025] * each indicates a position that is bonded to the above chemical formula 1.

[0026]

[0027] In addition, the present invention, in another embodiment,

[0028] An organic light-emitting device is provided comprising a first electrode, a second electrode, and one or more organic layers disposed between the first electrode and the second electrode, wherein one or more of the organic layers include the novel compound.

[0029] The organic layer containing the above novel compound may include one or more of an electron injection layer (EIL), an electron transport layer (ETL), a hole blocking layer (HBL), a layer that simultaneously injects and transports electrons, and a charge generation layer (CGL).

[0030]

[0031] In addition, the present invention, in another embodiment,

[0032] A tandem organic light-emitting device is provided, comprising: a first electrode and a second electrode; a plurality of light-emitting portions located between the first electrode and the second electrode; and a charge-generating layer located at one or more of the two adjacent light-emitting portions, wherein one or more of the charge-generating layers comprises an N-type charge-generating layer comprising the novel compound and the dopant.

[0033] The novel compound of the present invention can be applied to one or more layers among the electron injection layer (EIL), electron transport layer (ETL), hole blocking layer (HBL), layer that simultaneously injects and transports electrons, and charge generation layer (CGL) of an organic light-emitting device, and enables the improvement of performance such as low voltage, high efficiency, and long lifespan of the organic light-emitting device.

[0034] Specifically, the novel compound of the present invention, 1,10-phenanthroline, comprises a nitrogen atom in an electron-rich sp2 hybrid orbital, and said nitrogen atom can form a gap state by bonding with an alkali metal or alkaline earth metal used as a dopant in the N-type charge generation layer. The formation of such a gap state facilitates the smooth transfer of electrons from the N-type charge generation layer to the electron transport layer. In particular, 1,10-phenanthroline, possessing lone pairs of electrons, is suitable for application in the N-type charge generation layer due to its ease of bonding with metals. Furthermore, since the lone pairs of electrons possessed by the nitrogen atom of the terpyridine further facilitate bonding with metals, it may be applicable not only to Li but also to Yb. Additionally, the structure has a low RE value (reorganization energy) and a ratio of hole-to-electron mobility rate constants (k et (e) / k et Efficiency can be improved through (h)).

[0035] The above effects and additional effects are described in detail below.

[0036] Before describing the present invention in detail below, it should be understood that the terms used in this specification are intended only to describe specific embodiments and are not intended to limit the scope of the invention, which is defined solely by the appended claims. Unless otherwise stated, all technical and scientific terms used in this specification have the same meaning as generally understood by those skilled in the art.

[0037] In this specification, when a part is described as 'comprising' a certain component, it means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0038] In this specification, when a component is described as being 'on' another component, this includes not only cases where a component is in contact with another component, but also cases where another component exists between the two components.

[0039] In this specification, examples of substituents are described below, but are not limited thereto.

[0040] In this specification, the term "substitution" means that a hydrogen atom bonded to a carbon atom of a compound is replaced by another substituent. The position where substitution occurs is not particularly limited and can be any position where substitution is possible, and when two or more substituents are substituted, the substituents may be identical or different from each other.

[0041] In this specification, the term "substituted or unsubstituted" means being substituted with one or more substituents selected from the group consisting of deuterium, halogen group, cyano group, nitro group, nitrile group, alkyl group, alkenyl group, alkynyl group, cycloalkyl group, heterocycloalkyl group, alkoxy group, sulfide group, aryloxy group, heteroaryloxy group, thio group, amine group, silyl group, phosphine oxide group, aryl group, and heteroaryl group, being substituted with a substituent in which two or more substituents selected from said group are connected, or having no substituents at all, and the selected substituents may or may not be combined with each other to form a ring. An example of a substituent in which two or more substituents are connected is a biphenyl group. That is, the biphenyl group corresponds to an aryl group, and simultaneously corresponds to a substituent in which two phenyl groups are connected, and simultaneously corresponds to an aryl group substituted with one phenyl group.

[0042] In this specification, the alkyl group may be a straight chain or a branched chain having 1 to 60 carbon atoms, and specific examples include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methylbutyl, 1-ethylbutyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethylpropyl, 1,1-dimethylpropyl, Examples include isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl, etc., but are not limited thereto. Specifically, the number of carbon atoms in the alkyl group may be 1 to 30, and more specifically, 1 to 20.

[0043] In the present specification, the alkenyl group may be a straight chain or a branched chain having 2 to 60 carbon atoms, and specific examples include, but are not limited to, a vinyl group, a 1-propenyl group, an isopropenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1-pentenyl group, a 2-pentenyl group, a 3-pentenyl group, a 3-methyl-1-butenyl group, a 1,3-butadienyl group, an allyl group, a 1-phenylvinyl-1-yl group, a 2-phenylvinyl-1-yl group, a 2,2-diphenylvinyl-1-yl group, a 2-phenyl-2-(naphthyl-1-yl)vinyl-1-yl group, a 2,2-bis(diphenyl-1-yl)vinyl-1-yl group, a stilbenyl group, a styrenyl group, etc. Specifically, the number of carbon atoms in the alkenyl group can be 2 to 30, and more specifically, 2 to 20.

[0044] In the present specification, the alkynyl group may be a straight chain or a branched chain having 2 to 60 carbon atoms. Specifically, the number of carbon atoms in the alkynyl group may be 2 to 30, and more specifically, 2 to 20.

[0045] In the present specification, the alkoxy group may be a straight chain, branched chain, or cyclic chain having 1 to 60 carbon atoms, and specific examples include methoxy, ethoxy, n-propoxy, isopropoxy, i-propyloxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, n-pentyloxy, neopentyloxy, isopentyloxy, n-hexyloxy, 3,3-dimethylbutyloxy, 2-ethylbutyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, benzyloxy, p-methylbenzyloxy, etc., but are not limited thereto. Specifically, the number of carbon atoms of the alkoxy group may be 1 to 30, and more specifically, 1 to 20.

[0046] In the present specification, the cycloalkyl group may be a single or polycyclic group having 3 to 60 carbon atoms, and specific examples include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl, etc. Specifically, the number of carbon atoms of the cycloalkyl group may be 3 to 30, and more specifically, 3 to 20.

[0047] In the present specification, the heterocycloalkyl group comprises one or more non-carbon atoms, i.e., heteroatoms, and specifically may be a cycloalkyl group comprising one or more heteroatoms selected from the group consisting of O, N, S, and Se, and may be a monocyclic or polycyclic group having 2 to 60 carbon atoms. Specifically, the number of carbon atoms of the heterocycloalkyl group may be 2 to 30, and more specifically 2 to 20.

[0048] In the present specification, the sulfide group may include S and may have 1 to 60 carbon atoms. Specific examples include, but are not limited to, alkyl sulfide groups such as dimethyl sulfide, aryl sulfide groups such as diphenyl sulfide, and heteroaryl sulfide groups substituted with heteroaryl groups. Specifically, the number of carbon atoms of the sulfide group may be 1 to 30, and more specifically, 1 to 20.

[0049] In this specification, the aryloxy group may be a substituent comprising O, wherein the O atom is directly connected as a radical, and may have 6 to 60 carbon atoms. Specific examples of oxygen groups substituted with an aryl group include, but are not limited to, phenoxy groups, naphthoxy groups, and biphenoxy groups. The heteroaryloxy group may be an oxygen group substituted with a heteroaryl group, and may have 2 to 60 carbon atoms. Specifically, the number of carbon atoms of the aryloxy group may be 6 to 30, and more specifically, 6 to 20.

[0050] In the present specification, the thio group may include S and may have 1 to 60 carbon atoms. Specific examples include alkyl thio groups such as methyl thio group, ethyl thio group, butyl thio group, pentyl thio group, and hexyl thio group; aryl thio groups such as phenyl thio group and naphthyl thio group; and heteroaryl thio groups substituted with heteroaryl groups, but are not limited thereto. Specifically, the number of carbon atoms of the thio group may be 1 to 30, and more specifically, 1 to 20.

[0051] In the present specification, the silyl group may be a substituent comprising Si, in which the Si atom is directly connected as a radical, and may have 1 to 60 carbon atoms. Specific examples include alkylsilyl groups such as trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, vinyldimethylsilyl, and propyldimethylsilyl; arylsilyl groups such as triphenylsilyl, diphenylsilyl, and phenylsilyl; and heteroarylsilyl groups substituted with heteroaryl groups, but are not limited thereto. Specifically, the number of carbon atoms of the silyl group may be 1 to 30, and more specifically, 1 to 20.

[0052] In the present specification, the phosphine oxide group comprises P=O and may have 1 to 60 carbon atoms. Specific examples include, but are not limited to, alkylphosphine oxide groups such as dimethylphosphine oxide, arylphosphine oxide groups such as diphenylphosphine oxide and dinaphthylphosphine oxide, and heteroarylphosphine oxide groups substituted with heteroaryl groups. Specifically, the number of carbon atoms of the phosphine oxide group may be 1 to 30, and more specifically, 1 to 20.

[0053] In this specification, the aryl group may be monocyclic or polycyclic having 6 to 60 carbon atoms. Specific examples of monocyclic aryl groups may include, but are not limited to, phenyl groups, biphenyl groups, terphenyl groups, etc. Specific examples of polycyclic aryl groups may include, but are not limited to, naphthyl groups, anthracenyl groups, phenanthrenyl groups, triphenylenyl groups, pyrenyl groups, fluorenyl groups, etc. Specifically, the number of carbon atoms in the aryl group may be 6 to 50, and more specifically, 6 to 30.

[0054] In the present specification, the heteroaryl group comprises one or more atoms that are not carbon, i.e., heteroatoms, and specifically may comprise one or more heteroatoms selected from the group consisting of O, N, S and Se, and may be a single ring or a polycyclic group having 2 to 60 carbon atoms. Specific examples include thiophenyl group, furanyl group, pyrrolyl group, imidazolyl group, thiazolyl group, oxazolyl group, oxadiazolyl group, pyridinyl group, bipyridinyl group, pyrimidinyl group, triazolyl group, acrridinyl group, pyridazinyl group, pyrazinyl group, quinolinyl group, quinazolyl group, quinoxalinyl group, phthalazinyl group, pyridopyrimidinyl group, pyridopyrazinyl group, pyrazinopyrazinyl group, pyridoindolyl group, benzothienopyrimidyl group, indenocarbazolyl group, isoquinolinyl group, indolyl group, carbazolyl group, benzoxazolyl group, benzimidazolyl group, benzothiazolyl group, benzocarbazolyl group, benzothiophenyl group, Dibenzothiophenyl group, benzofuranyl group, phenanthridinyl group, phenanthrolinyl group, isooxazolyl group, thiadiazolyl group, phenothiazinyl group, and dibenzofuranyl group are included, but are not limited thereto. Specifically, the number of carbon atoms in the heteroaryl group may be 2 to 50, and more specifically, 2 to 30.

[0055] In the present specification, the amine group may be selected from the group consisting of -NH2, alkylamine group, N-alkylarylamine group, arylamine group, N-arylheteroarylamine group, N-alkylheteroarylamine group, and heteroarylamine group.

[0056] In this specification, an arylene group refers to a divalent aryl group having two bonding sites to an aryl group, and a heteroarylene group also refers to a divalent heteroaryl group having two bonding sites to a heteroaryl group. Except that they are each divalent groups, the descriptions of the arylene and heteroaryl groups described above may apply.

[0057] In the chemical formulas or structural formulas within this specification, * or indicates the joint location.

[0058] In this specification, the same symbols within a single chemical formula or structural formula may be the same or different from each other.

[0059] In this specification, "C2~C 50 When a range such as ", "0 to 7" is specified, even without special notation, it may be reduced to various ranges within the specified range and is deemed to be described in this specification. For example, C2~C 50 is C2~C 50 Along with C5~C 50 , C6~C 30 , C6~C 20 , C6~C 15 , C6~C 10 , C 12 ~C 30 It is deemed that various reduction ranges are described together. Accordingly, the description of numerical ranges in this specification may be corrected for reduction later.

[0060] Meanwhile, various embodiments of the present invention may be combined with any other embodiments unless explicitly pointed out otherwise.

[0061]

[0062] The present invention will be described in detail below.

[0063] The present invention relates to a novel compound and an organic light-emitting device containing the same.

[0064] Specifically, the novel compound of the present invention is represented by the following chemical formula 1.

[0065] <Chemical Formula 1>

[0066]

[0067] In the above chemical formula 1,

[0068] L1 and L2 are each independently directly bonded, substituted, or unsubstituted C6~C 30 The arylene group, or substituted or unsubstituted C2~C 30 It is a heteroarylene group, and

[0069] a and b are each independently integers from 0 to 3, and

[0070] Among the above Ar1 and the above Ar2, one is the following structural formula A and the other is the following structural formula B, and

[0071] <Structural Formula A>

[0072]

[0073] <Structural Formula B>

[0074]

[0075] In the above structural formulas A and B,

[0076] R is independently hydrogen, deuterium, halogen, cyano group, nitro group, nitrile group, or substituted or unsubstituted C1~C 30 alkyl groups, substituted or unsubstituted C1~C 30 alkenyl groups, substituted or unsubstituted C1~C 30 alkynyl groups, substituted or unsubstituted C3~C 30 cycloalkyl groups, substituted or unsubstituted C1~C 30 heterocycloalkyl groups, substituted or unsubstituted C1~C 30 alkoxy groups, substituted or unsubstituted C1~C 30 sulfide groups, substituted or unsubstituted C6~C 30 aryl groups, substituted or unsubstituted C2~C 30 heteroaryl groups, substituted or unsubstituted C6~C 30 The aryloxy group of, substituted or unsubstituted C2~C 30 heteroaryloxy groups of, substituted or unsubstituted C1~C 30 thiogroups, substituted or unsubstituted C1~C 30 amine groups, substituted or unsubstituted C1~C 30 The silyl group and substituted or unsubstituted C1~C 30 Selected from the group consisting of phosphine oxide groups, wherein adjacent ones may or may not combine to form a substituted or unsubstituted ring, and

[0077] n is an integer from 0 to 7, and

[0078] X is independently either N or CH, and

[0079] Y1 to Y3 are each independently N or CH, provided that at least one is N, and

[0080] Z1 to Z3 are each independently N or CH, and at least one is N, and

[0081] * each indicates a position that is bonded to the above chemical formula 1.

[0082] Here, in the definitions of Chemical Formula 1 and each of the following chemical formulas and structural formulas, the substituent in the case of 'substituted or unsubstituted' is, unless otherwise specifically defined, deuterium, halogen group, fluorine group (-F), cyano group (-CN), nitro group, nitrile group, hydroxyl group, thiol group, -CF3, C1~C 30 alkyl group of, C3~C 30 cycloalkyl group of, C1~C 30 heterocycloalkyl group of, C1~C 30 The silyl group of, C6~C 30 aryl group and C2~C 30It may consist of one or more selected heteroaryl groups. According to one embodiment, the substituent is deuterium, halogen group, fluorine group (-F), cyano group (-CN), nitro group, nitrile group, hydroxyl group, thiol group, -CF3, methyl group, ethyl group, t-butyl group, adamantyl group, norbornene group, cyclohexyl group, phenyl group, naphthyl group, biphenyl group, terphenyl group, phenanthrene group, pyrene group, fluoranthene group, chrysene group, anthracene group, benzoanthracene group, benzophenanthrene group, dimethylfluorene group, diphenylfluorene group, spirobifluorene group, trimethylsilyl group, triphenylsilyl group, silol group, pyridine group, pyrimidine group, pyridazine group, pyrazine group, triazine group, quinoline group, isoquinoline group, quinazolin group, naphthiridine group, benzofuran group, It may consist of one or more selected from dibenzofuran groups, benzothiophene groups, dibenzothiophene groups, benzoxazole groups, benzothiazole groups, carbazole groups, and phenanthroline groups, but is not specifically limited thereto.

[0083]

[0084] Meanwhile, regarding the above Chemical Formula 1, specifically according to one embodiment, the above Chemical Formula 1 may be the following Chemical Formula 2 or 3. The following Chemical Formula 2 is a case where structural Formula A, which is 1,10-phenanthroline, is bonded to the 1st position of naphthalene, and structural Formula B, which includes at least two N rings, is bonded to the 2nd position of naphthalene. And the following Chemical Formula 3 is a case where structural Formula B, which includes at least two N rings, is bonded to the 1st position, and structural Formula A, which is 1,10-phenanthroline, is bonded to the 2nd position of naphthalene.

[0085] <Chemical Formula 2>

[0086]

[0087] <Chemical Formula 3>

[0088]

[0089] In the above chemical formulas 2 and 3, L1, L2, a, b, R, n, X, Y1 to Y3, and Z1 to Z3 are the same as the definitions in the above chemical formula 1.

[0090] As such, the novel compound of the present invention has a structure in which structural formula A, which is 1,10-phenanthroline, and structural formula B, which includes at least two N rings, are bonded to a naphthalene center, and the bonding positions are the 1st and 2nd positions of the naphthalene.

[0091]

[0092] Meanwhile, the above structural formula A may specifically be the following structural formula A-1 or A-2. More specifically, it may be A-1.

[0093]

[0094] The definitions of R and n in the above structural formulas A-1 and A-2 are the same as in the above chemical formula 1, wherein in the above structural formula A-1, R does not bond with adjacent ones to form a ring, and in the above structural formula A-2, an aromatic hydrocarbon ring is condensed to at least one of A, B, and C.

[0095] Specifically, according to one embodiment, adjacent Rs may be combined to form a ring substituted or unsubstituted with one or more substituents, and specifically, a substituted or unsubstituted benzene may be formed. In this case, the 1,10-phenanthroline portion may specifically be represented by the structural formula A-2.

[0096] The above structural formula B may specifically be one of the following structural formulas B-1 to B-15. Specifically, it may be one of B-2, B-7, B-8, B-9, and B-14, and more specifically, it may be B-2.

[0097]

[0098]

[0099] Meanwhile, L1 and L2 of the above chemical formula 1 are each independently directly bonded, substituted, or unsubstituted C6~C 30 The arylene group, or substituted or unsubstituted C2~C 30 The heteroarylene group may be, specifically, one or more selected from the group consisting of a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted terphenylene group, a substituted or unsubstituted anthracenylene group, a substituted or unsubstituted phenanthrenylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyrimidylene group, a substituted or unsubstituted pyrazinylene group, a substituted or unsubstituted triazinylene group, a substituted or unsubstituted quinazolinylene, and a substituted or unsubstituted naphthyridinylene.

[0100] According to a more specific embodiment, L1 and L2 may each independently be a direct bond, a phenylene group, or a naphthalene group, and according to an even more specific embodiment, each may independently be a direct bond, a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a 1,2-naphthalene group, a 1,3-naphthalene group, a 1,4-naphthalene group, a 1,5-naphthalene group, a 1,6-naphthalene group, a 1,7-naphthalene group, a 1,8-naphthalene group, a 2,3-naphthalene group, a 2,6-naphthalene group, or a 2,7-naphthalene group. According to an embodiment, at least one of L1 and L2 may be selected from a 1,2-phenylene group, a 1,3-phenylene group, and a 1,4-phenylene group. Here, when a 1,3-phenylene group is introduced and the structure is bent to a meta, a relatively high LUMO energy level is obtained, which can facilitate electron transfer to the light-emitting layer.

[0101] Such L1 and L2 may be the same or different from each other, and multiple L1s or multiple L2s may also be the same or different from each other.

[0102]

[0103] Meanwhile, R of the above Chemical Formula 1 is each independently hydrogen, deuterium, halogen, cyano group, nitro group, nitrile group, or a substituted or unsubstituted C1~C 30 alkyl groups, substituted or unsubstituted C1~C 30 alkenyl groups, substituted or unsubstituted C1~C 30 alkynyl groups, substituted or unsubstituted C3~C 30 cycloalkyl groups, substituted or unsubstituted C1~C 30 heterocycloalkyl groups, substituted or unsubstituted C1~C 30 alkoxy groups, substituted or unsubstituted C1–C30 sulfide groups, substituted or unsubstituted C6–C 30 aryl groups, substituted or unsubstituted C2~C 30 heteroaryl groups, substituted or unsubstituted C6~C 30 The aryloxy group of, substituted or unsubstituted C2~C 30 heteroaryloxy groups of, substituted or unsubstituted C1~C 30 thiogroups, substituted or unsubstituted C1~C 30 amine groups, substituted or unsubstituted C1~C 30 The silyl group and substituted or unsubstituted C1~C 30 It is selected from the group consisting of phosphine oxide groups, but adjacent ones may combine with each other to form a substituted or unsubstituted ring, or may not form one.

[0104] According to a specific embodiment, R may each be independently selected from hydrogen, deuterium, cyano group, methyl group, phenyl group, naphthyl group, biphenyl group, terphenyl group, pyridinyl group, pyrimidinyl group, pyridazinyl group, pyrazinyl group, triazinyl group, quinoline group, isoquinoline group, quinazolin group, and naphthiridine group, more specifically may be hydrogen, phenyl group, pyridinyl group, pyrimidinyl group, or isoquinoline group, and even more specifically may be hydrogen or a phenyl group.

[0105]

[0106] Meanwhile, in the case of a and b of the above chemical formula 1 and n of the above structural formula A, a and b are each independently integers from 0 to 3, and n can be an integer from 0 to 7.

[0107] Here, n may be an integer from 0 to 3 according to a specific embodiment, more specifically an integer from 0 to 2, and even more specifically 0 or 1.

[0108] In addition, a and b may each be independently 0, 1, or 2 according to a specific embodiment, and a and b may be the same or different from each other. According to one embodiment, a+b may be an integer from 0 to 4, and if it is 4, it may be one or more selected from a phenylene group, a biphenylene group, and a naphthalene group. In addition, a+b may specifically be 1 or more, more specifically an integer from 1 to 3, and even more specifically 1 or 2.

[0109] According to a more specific embodiment, a+b may be 1, wherein linker L1 or L2 may be a phenylene group or a biphenylene group. Even more specifically, it may be a phenylene group.

[0110] According to another specific embodiment, a and b may each be 1, and in this case, linkers L1 and L2 may each be phenylene groups.

[0111] According to another specific embodiment, a may be 0 and b may be 1. For example, according to one embodiment, based on Formula 2, Structural Formula A, which is 1,10-phenanthroline, may be directly bonded to 1,2-naphthalene, and in the case of Structural Formula B, which is terpyridine, terpyridine may be bonded to 1,2-naphthalene by linker L2, wherein linker L2 may be a phenylene group, a biphenylene group, or naphthylene, and specifically as one example, may be a phenylene group. However, it is not limited thereto.

[0112] According to another specific embodiment, a may be 1 and b may be 0. For example, according to another embodiment, based on Formula 2, Structural Formula A, which is 1,10-phenanthroline, may be bonded to 1,2-naphthalene by linker L1, and as an example of Structural Formula B, terpyridine may be directly bonded to 1,2-naphthalene. In this case, linker L1 may be a phenylene group, a biphenylene group, or a naphthylene, and as a specific example, it may be a phenylene group. However, it is not limited thereto.

[0113] According to one embodiment of the present invention, the novel compound of the present invention represented by Chemical Formula 1 may be one of the following compounds 1 to 622. The following compounds are merely examples for explaining the present invention, and the present invention is not limited thereto.

[0114]

[0115]

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[0125]

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[0134]

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[0154]

[0155]

[0156] The novel compound of the present invention described so far specifically comprises structural formula A, wherein 1,10-phenanthroline includes a nitrogen atom in an electron-rich sp2 hybrid orbital, and said nitrogen atom can form a gap state by bonding with an alkali metal or alkaline earth metal used as a dopant in the N-type charge generation layer. The formation of such a gap state facilitates the smooth transfer of electrons from the N-type charge generation layer to the electron transport layer. In particular, 1,10-phenanthroline, which possesses non-covalent electron pairs, is suitable for application in the N-type charge generation layer because it easily bonds with dopants such as lithium and ytterbium. Furthermore, due to the structure bonded to the position immediately adjacent to N of 1,10-phenanthroline, conjugation is expanded, resulting in a lower RE value compared to other positions, which consequently increases the efficiency of the device.

[0157] Furthermore, as a specific example, if structural formula B is terpyridine, the lone pair of electrons on the nitrogen atom of terpyridine facilitates bonding with metals, so it may be applicable not only to Li but also to Yb. In addition, structures having low RE (reorganization energy) values ​​and the ratio of hole-to-electron mobility rate constants (k et (e) / k et Efficiency can be improved through (h)).

[0158] The novel compound of the present invention can be usefully applied to one or more organic layers among the electron transport layer (ETL), hole blocking layer (HBL), and charge generation layer (CGL) of an organic light-emitting diode. Here, the charge generation layer may be an N-type charge generation layer (N-CGL). In particular, the invention relates to a novel compound applicable to a charge generation layer (CGL), specifically an N-type charge generation layer (nCGL), in a tandem device, which can exhibit effects such as increased efficiency, reduced driving voltage, and extended lifespan. However, it is not limited thereto and can also be applied to organic layers such as the electron transport layer (ETL) and hole blocking layer (HBL) where a compound with excellent electron mobility is required.

[0159] The present invention comprises an organic light-emitting device comprising a first electrode and a second electrode, and one or more organic layers disposed between the first electrode and the second electrode, wherein one or more of the organic layers comprise a compound according to Formula 1. The organic layer comprising the compound may be a layer capable of transporting electrons, and specifically, may be one or more of an electron injection layer (EIL), an electron transport layer (ETL), a hole blocking layer (HBL), a layer that performs electron injection and transport simultaneously, and a charge generation layer (CGL). The charge generation layer may be an N-type charge generation layer (N-CGL). Such an organic light-emitting device may be a tandem-type organic light-emitting device comprising two or more emitting parts.

[0160] The organic light-emitting element according to the present invention will be described in more detail below.

[0161] An organic light-emitting device has an organic layer located between a first electrode and a second electrode. The organic layer may be composed of one or more organic layers, and specifically, it may be composed of one or more layers selected from known organic layers constituting a light-emitting part, such as a hole injection layer (HIL), a hole transport layer (HTL), an emitting layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL).

[0162] The hole injection layer (HIL) is a layer that injects holes from the electrode, and as the hole injection material, a compound that has the ability to transport holes, has an excellent hole injection effect at the anode and an excellent hole injection effect on the emitting layer or emitting material, prevents the movement of excitons generated in the emitting layer to the electron injection layer or electron injection material, and also has excellent thin film formation ability is preferred.

[0163] The hole transport layer (HTL) is a layer that receives holes from the hole injection layer and transports the holes to the emissive layer. As a hole transport material, a material capable of receiving holes from the anode or the hole injection layer and transferring them to the emissive layer, and a material with high mobility for holes is suitable.

[0164] The emissive layer (EML) is a layer that emits light through the recombination of electrons and holes. As the emissive material, it is a material capable of emitting light in the visible light region by receiving and combining holes and electrons from the hole transport layer and the electron transport layer, respectively, and a material with good quantum efficiency for fluorescence or phosphorescence is preferred. Specifically, the emissive layer may include a host and a dopant.

[0165] The electron transport layer (ETL) is a layer that receives electrons from the electron injection layer and transports them to the light-emitting layer. As an electron transport material, it is desirable to have a material that can effectively receive electrons from the cathode and transfer them to the light-emitting layer, and has high electron mobility.

[0166] The electron injection layer (EIL) is a layer that injects electrons from an electrode and has the ability to transport electrons, has an excellent electron injection effect from the cathode, an excellent electron injection effect on the emitting layer or emitting material, prevents the movement of excitons generated in the emitting layer to the hole injection layer, and also has excellent thin film formation ability. A compound is preferred.

[0167] Meanwhile, the organic layer may further include a hole blocking layer (hole defense layer, hole blocking layer, hole blocking layer, or HBL). The hole blocking layer may be located between the emissive layer and the electron transport layer and reduces the problem of holes from the hole injection layer intruding into the electron transport layer. As the hole blocking layer is also one of the layers in the electron transport region, a material capable of transporting electrons is suitable.

[0168] In addition, the organic layer may further include a layer that simultaneously performs electron injection and transport.

[0169] Among the organic layers of such organic light-emitting devices, the novel compound according to Formula 1 of the present invention is a material with excellent electron transport capability and can be applied to one or more layers among the electron injection layer, electron transport layer, hole blocking layer, and layers that simultaneously inject and transport electrons.

[0170] Meanwhile, the configuration of the organic light-emitting device may be varied or modified in various ways. According to one embodiment, the device may be a tandem-type organic light-emitting device in which two or more light-emitting parts (or light-emitting units) including a light-emitting layer between a first electrode and a second electrode are stacked. In the case of such a tandem structure, in addition to the organic layers mentioned above, a charge generation layer (CGL) that controls the balance of charges may be further included as one of the organic layers and may be located at one or more locations between two adjacent light-emitting parts. This charge generation layer may be composed of multiple layers including an N-type charge generation layer that acts to inject electrons and a P-type charge generation layer that acts to inject holes, but is not limited thereto and may be composed of a single layer.

[0171] The novel compound of the present invention can be applied to the charge generation layer of such a tandem organic light-emitting diode, specifically to the N-type charge generation layer. The N-type charge generation layer may be composed of an organic layer doped with a dopant such as a metal, and specifically may be composed of a host and a dopant. The novel compound of the present invention can be applied as a host for the N-type charge generation layer, and the compound of the present invention includes 1,10-phenantrolene having a non-covalent electron pair, enabling smooth interaction with the dopant.

[0172] Meanwhile, the dopant may be a material containing a metal element, and specifically, may be one or more of a metal, a metal compound, or an organic complex of a metal. The metal element may be, in detail, one or more selected from lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), ytterbium (Yb), samarium (Sm), tin (Sn), copper (Cu), titanium (Ti), cadmium (Cd), mercury (Hg), lead (Pb), bismuth (Bi), zinc (Zn), iron (Fe), cobalt (Co), nickel (Ni), indium (In), gallium (Ga), thorium (Th), uranium (U), silver (Ag), aluminum (Al), gold (Au), molybdenum (Mo), niobium (Nb), palladium (Pd), platinum (Pt), and europium (Eu), and may be lithium or ytterbium according to one embodiment. The proportion of these dopants can be doped to 0.1 to 20 wt% relative to the total host material, specifically to 0.5 to 15 wt%, and this is not limited and may vary depending on the type of metal element.

[0173]

[0174] The present invention will be explained in more detail below through synthetic examples, experimental examples, and embodiments. However, the following contents do not limit the scope of the present invention.

[0175]

[0176] Synthesis Example: Synthesis of Compounds

[0177] [Synthesis Example 1] Synthesis of Compound 6

[0178]

[0179] 1) Synthesis of Compound M1

[0180] 1-bromo-2-chloronaphthalene SM1 (70 g, 289.8 mmol) and Bis(pinacolato)diboron (95.68 g, 376.8 mmol) were added to a 2000 ml round-bottom flask. Pd(dppf)Cl2 (10.60 g, 14.5 mmol) and KOAc (85.34 g, 869.5 mmol) were added, and the mixture was stirred under reflux for 6 hours in 1400 ml of 1,4-Dioxane. Once the reaction was complete, the mixture was cooled to room temperature, extracted using EA / H2O, and the organic layer was dried under reduced pressure. Subsequently, compound M1 (73.7 g, 94.13%) was obtained by purification using column chromatography (EA:Hexane = 1:8).

[0181] 2) Synthesis of Compound M2

[0182] 4'-chloro-2,2':6',2''-terpyridine (A) (30 g, 112.1 mmol) and compound M1 (38.81 g, 134.5 mmol) were added to a 1000 ml round-bottom flask. Pd(PPh3)4 (6.474 g, 5.6 mmol) and K2CO3 (30.98 g, 224.1 mmol) were added, and the mixture was stirred under reflux for 12 hours in a mixture of 400 ml of dioxane and 200 ml of H2O. Once the reaction was complete, the mixture was cooled to room temperature, extracted with EA / H2O, and the organic layer was dried under reduced pressure. Compound M2 (22.3 g, 50.64%) was obtained by recrystallization with hexane.

[0183] 3) Synthesis of Compound 6

[0184] 2-phenyl-9-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1,10-phenanthroline (B) (31.14 g, 67.9 mmol) and compound M2 (22.3 g, 56.6 mmol) were added to a 500 ml round-bottom flask. Pd(PPh3)4 (3.27 g, 2.8 mmol) and K2CO3 (15.65 g, 113.2 mmol) were added, and the mixture was stirred under reflux for 12 hours in a mixed solution of 200 ml of dioxane and 100 ml of H2O. Once the reaction was complete, the mixture was cooled to room temperature, extracted with EA / H2O, and the organic layer was dried under reduced pressure. Subsequently, compound 6 (26.4 g, 67.60%) was obtained by purification and recrystallization.

[0185]

[0186] [Synthesization Example 2] Synthesis of Compounds 2, 3, 4, 5, 7, 142, 143, and 144

[0187] Compounds 2, 3, 4, 5, 7, 142, 143, and 144 were synthesized in the same manner as the synthesis of Synthesis Example 1, except that intermediate A of Table 1 below was used instead of 4'-chloro-2,2':6',2''-terpyridine (A) in Synthesis Example 1 above, and intermediate B of Table 1 below was used instead of 2-phenyl-9-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1,10-phenanthroline (B) below.

[0188] [Table 1]

[0189]

[0190]

[0191]

[0192] [Synthesis Example 3] Synthesis of Compound 246

[0193]

[0194] 1) Synthesis of Compound M3

[0195] 2-bromo-1-chloronaphthalene (50 g, 207.0 mmol) and Bis(pinacolato)diboron (72.05 g, 269.1 mmol) were added to a 2000 ml round-bottom flask. Pd(dppf)Cl2 (7.57 g, 10.4 mmol) and KOAc (60.95 g, 621.1 mmol) were added, and the mixture was stirred under reflux for 6 hours in 1000 ml of 1,4-Dioxane. Once the reaction was complete, the mixture was cooled to room temperature, extracted with EA / H2O, and the organic layer was dried under reduced pressure. Subsequently, the mixture was purified by column chromatography (EA:Hexane = 1:8) to obtain compound M3 (51.9 g, 87.01%).

[0196] 2) Synthesis of Compound M4

[0197] 4'-chloro-2,2':6',2''-terpyridine (C) (40.0 g, 149.4 mmol) and compound M3 (51.66 g, 179.3 mmol) were added to a 1000 ml round-bottom flask. Pd(PPh3)4 (8.63 g, 7.5 mmol) and K2CO3 (41.3 g, 298.8 mmol) were added, and the mixture was stirred under reflux for 12 hours in a mixture of 500 ml of dioxane and 250 ml of H2O. Once the reaction was complete, the mixture was cooled to room temperature, extracted with EA / H2O, and the organic layer was dried under reduced pressure. Compound M4 (38.7 g, 65.76%) was obtained by recrystallization with hexane.

[0198] 3) Synthesis of Compound 246

[0199] 2-phenyl-9-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1,10-phenanthroline (D) (53.07 g, 115.8 mmol) and compound M4 (38.0 g, 96.5 mmol) were added to a 500 ml round-bottom flask. Pd(PPh3)4 (5.57 g, 4.8 mmol) and K2CO3 (26.67 g, 193.0 mmol) were added, and the mixture was stirred under reflux for 12 hours in a mixed solution of 300 ml of dioxane and 150 ml of H2O. Once the reaction was complete, the mixture was cooled to room temperature, extracted with EA / H2O, and the organic layer was dried under reduced pressure. Subsequently, compound 246 (51.6 g, 77.53%) was obtained by recrystallization.

[0200]

[0201] [Synthesization Example 4] Synthesis of Compounds 242, 243, 244, 245, and 247

[0202] Compounds 242, 243, 244, 245, and 247 were synthesized in the same manner as the synthesis of Synthesis Example 3, except that intermediate C of Table 2 below was used instead of 4'-chloro-2,2':6',2''-terpyridine (C) in Synthesis Example 3, and intermediate D of Table 2 below was used instead of 2-phenyl-9-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-1,10-phenanthroline (D).

[0203] [Table 2]

[0204]

[0205] Fabrication of Organic Light Emitting Diodes: Use of Yb Dopant

[0206] [Comparison Example 1]

[0207] After forming an anode by patterning an ITO substrate to have a light-emitting area of ​​2mm x 2mm, the substrate was cleaned with isopropyl alcohol and UV ozone, respectively. Subsequently, the ITO substrate was mounted in the holder of a vacuum deposition equipment, and the vacuum level was set to 1x10 -7 Pressure was applied to torr. Plasma treatment was performed for 3 minutes under an N2 atmosphere. A HAT-CN compound was vacuum-deposited to a thickness of 5 nm on the substrate to form a first hole injection layer (HIL), and an NPB material was formed to a thickness of 20 nm on top of it as a first hole transport layer (HTL). Subsequently, a green first emissive layer was formed by vacuum-depositing a GH-1 material as the host of the emissive layer (EML) and a GD-1 material as the dopant of the emissive layer to a thickness of 20 nm at a mass ratio of approximately 10%. On top of this, a TmPyPB material was vacuum-deposited to a thickness of 20 nm as a first electron transport layer (ETL). An N-type charge generation layer was formed by vacuum-depositing a BPhen material as the host and a Yb material as the dopant to a thickness of 10 nm at a mass ratio of approximately 2% on top of the electron transport layer. A P-type charge generation layer was formed on top of it by depositing HAT-CN material to a thickness of 5 nm, and this layer is also utilized as a second hole injection layer. Subsequently, a second hole transport layer was formed by vacuum depositing NPB material to a thickness of 50 nm. On top of this, a green second light-emitting layer was formed by vacuum depositing GH-1 material as the host and GD-1 material as the dopant to a thickness of 20 nm, with a mass ratio of approximately 10%. Subsequently, a second electron transport layer was formed to a thickness of 20 nm using TmPyPB material as the host and Liq material as the dopant, with a mass ratio of approximately 33%. On top of this, LiF material was formed as an electron injection layer to a thickness of 1 nm by vacuum depositing. An organic light-emitting device was fabricated by forming Al as the cathode to a thickness of 50 nm. The structures of the HAT-CN, NPB, GH-1, GD-1, TmPyPB, BPhen, and Liq materials used in the organic light-emitting device are shown in Table 3 below.

[0208] [Table 3]

[0209]

[0210] [Comparison Examples 2 to 9]

[0211] Instead of BPhen as the N-type charge generation layer, the comparative compounds in Table 4 below were used, respectively, and an organic light-emitting device was fabricated in the same manner as Comparative Example 1 otherwise.

[0212] [Table 4]

[0213]

[0214] [Examples 1 to 15]

[0215] An organic light-emitting diode was fabricated in the same manner as Comparative Example 1, except that the compounds of the present invention synthesized in the previous synthesis example were used instead of BPhen as the N-type charge generating layer.

[0216]

[0217] Experimental Example 1. Evaluation of Organic Light Emitting Diode: N-Type Charge Generation Layer

[0218] The previously fabricated organic light-emitting diode at a driving current density of 10 mA / cm² 2 The driving voltage, current efficiency, and lifespan were evaluated, respectively. The evaluation results are shown in Table 5 below.

[0219] [Table 5]

[0220]

[0221] Fabrication of Organic Light Emitting Devices: Use of Li Dopants

[0222] [Comparison Example 10]

[0223] After forming an anode by patterning an ITO substrate to have a light-emitting area of ​​2mm x 2mm, the substrate was cleaned with isopropyl alcohol and UV ozone, respectively. Subsequently, the ITO substrate was mounted in the holder of a vacuum deposition equipment, and the vacuum level was set to 1x10 -7Pressure was applied to torr. Plasma treatment was performed for 3 minutes under an N2 atmosphere. A HAT-CN compound was vacuum-deposited to a thickness of 5 nm on the substrate to form a first hole injection layer (HIL), and an NPB material was formed to a thickness of 20 nm on top of it as a first hole transport layer (HTL). Subsequently, a green first emissive layer was formed by vacuum-depositing a GH-1 material as the host of the emissive layer (EML) and a GD-1 material as the dopant of the emissive layer to a thickness of 20 nm at a mass ratio of approximately 10%. On top of this, a TmPyPB material was vacuum-deposited to a thickness of 20 nm as a first electron transport layer (ETL). An N-type charge generation layer was formed by vacuum-depositing a BPhen material as the host and a Li material as the dopant to a thickness of 10 nm at a mass ratio of approximately 2% on top of the electron transport layer. A P-type charge generation layer was formed on top of this by depositing HAT-CN material to a thickness of 5 nm, and this layer is also utilized as a second hole injection layer. Subsequently, a second hole transport layer was formed by vacuum depositing NPB material to a thickness of 50 nm. On top of this, a green second light-emitting layer was formed by vacuum depositing GH-1 material as the host and GD-1 material as the dopant to a thickness of 20 nm, with a mass ratio of approximately 10%. Subsequently, a second electron transport layer was formed to a thickness of 20 nm using TmPyPB material as the host and Liq material as the dopant, with a mass ratio of approximately 33%. On top of this, LiF material was formed as an electron injection layer to a thickness of 1 nm by vacuum depositing. An organic light-emitting device was fabricated by forming Al as the cathode to a thickness of 50 nm. The structures of the HAT-CN, NPB, GH-1, GD-1, TmPyPB, BPhen, and Liq materials used in the organic light-emitting device are shown in Table 3 above.

[0224]

[0225] [Comparative Examples 11 to 18]

[0226] Instead of BPhen as the N-type charge generation layer, the comparative compounds in Table 4 above were used, respectively, and an organic light-emitting device was fabricated in the same manner as Comparative Example 10.

[0227]

[0228] [Examples 16 to 30]

[0229] An organic light-emitting diode was fabricated in the same manner as Comparative Example 10, except that the compounds of the present invention synthesized in the previous synthesis example were used instead of BPhen as the N-type charge generating layer.

[0230]

[0231] Experimental Example 2. Evaluation of Organic Light Emitting Diode: N-Type Charge Generation Layer

[0232] The previously fabricated organic light-emitting diode at a driving current density of 10 mA / cm² 2 The driving voltage, current efficiency, and lifespan were evaluated, respectively. The evaluation results are shown in Table 6 below.

[0233] [Table 6]

[0234]

[0235] As shown in Tables 5 and 6 above, it was confirmed that an organic light-emitting device using the compounds of the present invention as an N-type charge generation layer material has a lower driving voltage compared to an organic light-emitting device using comparative compounds, and exhibits excellent characteristics in terms of luminous efficiency and lifespan stability.

[0236] Specifically, since nitrogen atoms have high electronegativity, aromatic heterocycles containing nitrogen atoms have high electron affinity. Compounds with high electron affinity readily accept electrons from the cathode, thereby enabling operation at lower voltages. Additionally, as the amount of electrons supplied to the light-emitting layer increases, the probability of charge recombination improves, and as a result, luminous efficiency can be improved.

[0237] In addition, according to the present invention, the nitrogen-containing compound contains two or more nitrogen atoms, thereby increasing electron density and improving electron mobility, which facilitates electron transport. In particular, by introducing electron-rich 1,10-phenanthroline into the N-type charge generation layer, electron transfer to the adjacent light-emitting layer can be facilitated. Furthermore, when the nitrogen-containing compound is combined with an alkali metal or an alkaline earth metal, the diffusion of the metal into the P-type charge generation layer can be suppressed, thereby improving the lifespan of the device.

[0238] In particular, as an example, when terpyridine is introduced, terpyridine exhibits superior electron transport compared to bipyridine and can act as a substituent with high coordination affinity for metal atoms, which may be desirable. Meanwhile, biphenyl has a structure in which two phenyl rings are twisted, which may limit π-conjugation, whereas naphthalene has a planar structure, which can improve π-conjugation and intermolecular packing, thereby improving electron mobility and lowering the electron injection barrier, which may enable low-voltage operation.

[0239] However, excessive planarity strengthens π-π stacking, which increases crystallinity and can lead to non-uniformity of luminescence and reduced device lifespan. In contrast, the 1,2-naphthalene compound, which is the core of the present invention, has appropriate steric hindrance and can improve stability by suppressing excessive π-π stacking.

[0240] In addition, compared to the case where terpyridine is bound to the 1st position of naphthalene, when terpyridine is bound to the 2nd position, steric interference is relatively less, so planarity is maintained and π-conjugation is stably maintained, which can improve electron mobility.

[0241] [Table 7]

[0242]

[0243] Using the Gaussian 09 program, the RE values ​​(reorganization energy) and the ratio of hole-to-electron transport rate constants (Ket(e) / Ket(h)) for Comparison Compound 1 and Compounds 2, 5, and 246 at the DFT b3lyp / 6-31g(d) level were calculated and listed in Table 7. A smaller reorganization energy reduces charge loss during the charge recombination process, allowing for smoother charge transport and thus increasing the efficiency of the organic light-emitting diode. An electron / hole rate constant closer to 1 indicates that electrons and holes move at nearly the same speed, allowing for a more even distribution within the organic layer. This suggests that charge recombination efficiency can be increased, and by positioning the recombination region near the center rather than near the interface of the electron or hole transport layer, the driving voltage can be lowered and current efficiency increased.

[0244] Comparative compound 1, which has a 1,4-naphthalene core, exhibits an electron / hole rate constant value of 0.19, which deviates significantly from 1. In contrast, compounds 2, 5, and 246, which have a 1,2-naphthalene core and a rate constant ratio (Ket(e) / ket(h)) close to 1, can provide lower driving voltage and higher current efficiency than comparative compound 1. Additionally, compound 246, which has a 1,2-naphthalene core and a terpyridine bonded at the 2nd position, exhibits characteristics such as a lower reorganization energy (RE) value and a rate constant ratio (ket(e) / ket(h)) close to 1 compared to compounds 2 and 5, which have a terpyridine bonded at the 1st position, and can provide lower driving voltage and higher current efficiency than compounds 2 and 5. More specifically, it can be confirmed through Tables 5 and 6 above that the voltage, current, and lifespan are superior when terpyridine is bonded at position 2 while having a 1,2-naphthalene core compared to when terpyridine is bonded at position 1. Additionally, it can be confirmed through Tables 5 and 6 above that the performance is superior when terpyridine is directly bonded to the 1,2-naphthalene core compared to when it is bonded to the 1,2-naphthalene core by a linker.

[0245] [Table 8]

[0246]

[0247] The compound according to the present invention has excellent thermal stability, with a glass transition temperature (Tg) of 150°C or higher and a decomposition temperature (Td) at which the mass of the compound decreases by 5% when heated. 5%It can be confirmed that the temperature is above 440°C. Compared to Comparative Compound 2, which has a 1,3-naphthalene core, and Comparative Compound 4, which has a phenyl linker, Comparative Compound 246, which has appropriate steric hindrance, exhibits a higher Tg value because the molecules are rigidly fixed due to structural constraints and molecular movement is reduced. Additionally, since the molecular weight of terpyridine is larger than that of bipyridine, it can be confirmed that Comparative Compound 246 has a higher Tg value than Comparative Compound 5. This increase in thermal stability can be an important factor in providing operational stability to the device.

[0248] [Table 9]

[0249]

[0250] The electron transfer values ​​of Comparative Compounds 6 and 7 and Compounds 2, 4, and 7 at the DFT b3lyp / 6-31g(d) level were calculated using the Gaussian 09 program and are listed in Table 9. nCGL transfers electrons by maintaining a bonded form with a metal. The work function energy can change depending on the bonding strength with the metal, and in the case of strong bonding, the work function energy approaches the Fermi level energy, which can improve electron transfer capability. Improved electron transfer capability allows for a lower driving voltage and higher current efficiency. Therefore, since Compounds 2, 4, and 7, which have a 1,2-naphthalene core, have higher electron transfer values ​​than Comparative Compounds 6 and 7, which contain 1,4-naphthalene and 1,3-naphthalene, they can have lower driving voltage and higher current efficiency.

[0251] Accordingly, according to the present invention, the novel compound has a structure in which structural formula A, which is 1,10-phenanthroline, and structural formula B, which includes at least two N rings, are bonded to a naphthalene center, and the bonding positions are at positions 1 and 2 of the naphthalene. Specifically, the novel compound of the present invention comprises 1,10-phenanthroline containing a nitrogen atom in an electron-rich sp2 hybrid orbital, and said nitrogen atom can bond with an alkali metal or alkaline earth metal used as a dopant in the N-type charge generation layer to form a gap state. Through the formation of such a gap state, electron transfer from the N-type charge generation layer to the electron transport layer is facilitated. In particular, 1,10-phenanthroline, which has non-covalent electron pairs, is easy to bond with metals and may be suitable for application in the N-type charge generation layer. Furthermore, in the case of terpyridine, an example of structural formula B, the lone pair of electrons on the nitrogen atom facilitates bonding with the metal, so it may be applicable not only to Li but also to Yb. In addition, structures with low RE (reorganization energy) values ​​and the ratio of hole-to-electron mobility rate constants (k) et (e) / k et The efficiency increase can be improved through (h). Therefore, the novel compound of the present invention can be usefully applied to one or more organic layers among the electron transport layer (ETL), hole blocking layer (HBL), and N-type charge generation layer (NCGL) of an organic light-emitting device, and in particular, when applied to a host of the N-type charge generation layer of a tandem organic light-emitting device, it can enable the realization of low voltage, high efficiency, and long lifespan of the device.

Claims

1. A novel compound represented by the following chemical formula 1: <Chemical Formula 1> In the above chemical formula 1, L1 and L2 are each independently directly bonded, substituted, or unsubstituted C6~C 30 The arylene group, or substituted or unsubstituted C2~C 30 It is a heteroarylene group, and a and b are each independently integers from 0 to 3, and Among the above Ar1 and the above Ar2, one is the following structural formula A and the other is the following structural formula B, and <Structural Formula A> <Structural Formula B> In the above structural formulas A and B, R is independently hydrogen, deuterium, halogen, cyano group, nitro group, nitrile group, or substituted or unsubstituted C1~C 30 alkyl groups, substituted or unsubstituted C1~C 30 alkenyl groups, substituted or unsubstituted C1~C 30 alkynyl groups, substituted or unsubstituted C3~C 30 cycloalkyl groups, substituted or unsubstituted C1~C 30 heterocycloalkyl groups, substituted or unsubstituted C1~C 30 alkoxy groups, substituted or unsubstituted C1~C 30 sulfide groups, substituted or unsubstituted C6~C 30 aryl groups, substituted or unsubstituted C2~C 30 heteroaryl groups, substituted or unsubstituted C6~C 30 The aryloxy group of, substituted or unsubstituted C2~C 30 heteroaryloxy groups of, substituted or unsubstituted C1~C 30 thiogroups, substituted or unsubstituted C1~C 30 amine groups, substituted or unsubstituted C1~C 30 The silyl group and substituted or unsubstituted C1~C 30 Selected from the group consisting of phosphine oxide groups, wherein adjacent ones may or may not combine to form a substituted or unsubstituted ring, and n is an integer from 0 to 7, and X is independently either N or CH, and Y1 to Y3 are each independently N or CH, provided that at least one is N, and Z1 to Z3 are each independently N or CH, and at least one is N, and * each indicates a position that is bonded to the above chemical formula 1.

2. In Paragraph 1, A novel compound characterized in that the above chemical formula 1 is the following chemical formula 2 or 3: <Chemical Formula 2> <Chemical Formula 3> In the above chemical formulas 2 and 3, L1, L2, a, b, R, n, X, Y1 to Y3, and Z1 to Z3 are the same as the definitions in the above chemical formula 1.

3. In Paragraph 1, A novel compound characterized in that the above structural formula A is the following structural formula A-1 or A-2: The definitions of R and n in the above structural formulas A-1 and A-2 are the same as in the above chemical formula 1, wherein in the above structural formula A-1, R does not bond with adjacent ones to form a ring, and in the above structural formula A-2, an aromatic hydrocarbon ring is condensed to at least one of A, B, and C.

4. In Paragraph 1, A novel compound characterized in that the above structural formula B is one of the following structural formulas B-1 to B-15:

5. In Paragraph 1, A novel compound characterized in that L1 and L2 of the above chemical formula 1 are each independently direct bonds, or are selected from the group consisting of a substituted or unsubstituted phenylene group, a substituted or unsubstituted naphthylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted terphenylene group, a substituted or unsubstituted anthracenylene group, a substituted or unsubstituted phenanthrenylene group, a substituted or unsubstituted pyridylene group, a substituted or unsubstituted pyrimidylene group, a substituted or unsubstituted pyrazinilene group, a substituted or unsubstituted triazinilene group, a substituted or unsubstituted quinazolinylene, and a substituted or unsubstituted naphthyridinylene.

6. In Paragraph 1, A novel compound characterized in that R of the above chemical formula 1 is each independently selected from the group consisting of hydrogen, deuterium, cyano group, methyl group, phenyl group, naphthyl group, biphenyl group, terphenyl group, pyridinyl group, pyrimidinyl group, pyridazinyl group, pyrazinyl group, triazinyl group, quinoline group, isoquinoline group, quinazolin group, and naphthiridine group.

7. In Paragraph 1, A novel compound characterized in that the compound represented by the above chemical formula 1 is one of the following compounds 1 to 622:

8. First electrode and second electrode; It includes one or more organic layers disposed between the first electrode and the second electrode, and An organic light-emitting device characterized in that one or more of the above organic layers comprise a compound according to any one of claims 1 to 7.

9. In Paragraph 8, An organic light-emitting device characterized in that the organic layer containing the above compound is one or more of an electron injection layer, an electron transport layer, a hole blocking layer, a layer that simultaneously injects and transports electrons, and a charge generation layer.

10. First electrode and second electrode; A plurality of light-emitting parts located between the first electrode and the second electrode; and It includes a charge generation layer located at one or more of the locations between two adjacent light-emitting parts, and A tandem organic light-emitting diode comprising one or more of the above charge-generating layers, wherein the charge-generating layers comprise an N-type charge-generating layer comprising a compound and a dopant represented by the following chemical formula 1: <Chemical Formula 1> In the above chemical formula 1, L1 and L2 are each independently directly bonded, substituted, or unsubstituted C6~C 30 The arylene group, or substituted or unsubstituted C2~C 30 It is a heteroarylene group, and a and b are each independently integers from 0 to 3, and Among the above Ar1 and the above Ar2, one is the following structural formula A and the other is the following structural formula B, and <Structural Formula A> <Structural Formula B> In the above structural formulas A and B, R is independently hydrogen, deuterium, halogen, cyano group, nitro group, nitrile group, or substituted or unsubstituted C1~C 30 alkyl groups, substituted or unsubstituted C1~C 30 alkenyl groups, substituted or unsubstituted C1~C 30 alkynyl groups, substituted or unsubstituted C3~C 30 cycloalkyl groups, substituted or unsubstituted C1~C 30 heterocycloalkyl groups, substituted or unsubstituted C1~C 30 alkoxy groups, substituted or unsubstituted C1~C 30 sulfide groups, substituted or unsubstituted C6~C 30 aryl groups, substituted or unsubstituted C2~C 30 heteroaryl groups, substituted or unsubstituted C6~C 30 The aryloxy group of, substituted or unsubstituted C2~C 30 heteroaryloxy groups of, substituted or unsubstituted C1~C 30 thiogroups, substituted or unsubstituted C1~C 30 amine groups, substituted or unsubstituted C1~C 30 The silyl group and substituted or unsubstituted C1~C 30 Selected from the group consisting of phosphine oxide groups, wherein adjacent ones may or may not combine to form a substituted or unsubstituted ring, and n is an integer from 0 to 7, and X is independently either N or CH, and Y1 to Y3 are each independently N or CH, provided that at least one is N, and Z1 to Z3 are each independently N or CH, and at least one is N, and * each indicates a position that is bonded to the above chemical formula 1.

11. In Paragraph 10, A tandem organic light-emitting diode characterized in that the above-mentioned dopant comprises one or more selected from lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), ytterbium (Yb), samarium (Sm), tin (Sn), copper (Cu), titanium (Ti), cadmium (Cd), mercury (Hg), lead (Pb), bismuth (Bi), zinc (Zn), iron (Fe), cobalt (Co), nickel (Ni), indium (In), gallium (Ga), thorium (Th), uranium (U), silver (Ag), aluminum (Al), gold (Au), molybdenum (Mo), niobium (Nb), palladium (Pd), platinum (Pt), and europium (Eu).

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