Compound, light-emitting device, display apparatus, electronic device, and illumination apparatus

Abstract

The present invention provides a compound of general formula 1, a light-emitting device comprising the compound, a display apparatus, an electronic device, and an illumination apparatus. The compound of the present invention has a specific structure comprising fluoranthene and phenanthroline. The present invention can provide an organic thin film light-emitting element that simultaneously achieves high light-emitting efficiency, low driving voltage and long lifetime.

Description

Compound, light-emitting device, display device, electronic device, and lighting device TECHNICAL FIELD

[0001] The present application relates to a compound, a light-emitting device including the compound, a display device, an electronic device, and a lighting device. BACKGROUND

[0002] An OLED device is a light-emitting device including an anode, a cathode, and an organic layer interposed therebetween, and the organic layer emits light using electric energy. In recent years, OLED devices have been used for display screens of televisions, smartphones, and the like, and have gradually entered the practical stage. However, the existing OLED devices still have many technical problems. Among them, simultaneous achievement of high efficiency and long lifetime of OLED has become a major issue.

[0003] As a compound that solves these problems, a phenanthroline derivative having a specific fluoranthene skeleton has been developed (see Patent Documents 1 to 3).

[0004] According to the technology described in Patent Documents 1 to 3, an OLED device having improved light-emitting efficiency, reduced driving voltage, and excellent durability can be obtained. As an example of the existing compound having a nitrogen-containing aromatic heterocycle and a fluoranthene skeleton, the following compounds X, Y, and Z disclosed in Patent Documents 1 to 3 can be given.

[0005] However, in recent years, the light-emitting efficiency and durability required for OLED devices have been increasing, and the performance of an OLED device using these compounds as an electron injection layer, an electron transport layer, or a charge generation layer cannot sufficiently satisfy the characteristics required in recent years.

[0006] For example, in the phenanthroline derivatives having a fluoranthene skeleton such as compounds X, Y, and Z, an arylene group connecting the fluoranthene and the phenanthroline is selected from a para arylene group or a meta arylene group. Both the fluoranthene and the phenanthroline are highly crystalline substituents, and if these groups are connected using a para arylene group or a meta arylene group, the crystallinity of the entire molecule can be excessively increased to increase the sublimation temperature. When these compounds are vapor-deposited together with a metal to form a film, a problem of significantly reduced film stability and handling properties can occur.

[0007] For example, in the phenanthroline derivative using an anthracenylene group such as compound Z, the highly crystalline fluoranthene structure and the phenanthroline structure are further added with an anthracene group, and the compound Z resulting from the use of a para arylene group in these structures can cause the crystallinity to be excessively increased to increase the sublimation temperature. Therefore, when these compounds are vapor-deposited together with a metal to form a film, a problem of significantly reduced film stability and handling properties can occur to reduce the device lifetime.

[0008] [Patent Document]

[0009] [Patent Literature]

[0010] [Patent Literature 1] International Publication No. 2015 / 182547

[0011] [Patent Literature 2] International Publication No. 2016 / 121597

[0012] [Patent Literature 3] Korean Patent Application Publication No. 2016-0046046 SUMMARY

[0013] In recent years, the light emission efficiency and durability required for an OLED device are increasingly improved, and a technology capable of further simultaneously achieving higher light emission efficiency and durability is needed.

[0014] In view of the problems of the related art, an object of the present application is to provide an OLED device having excellent light emission efficiency and durability life.

[0015] To solve the above problem, the present application is constituted by the following:

[0016] (1). A compound having the following structure represented by General Formula 1:

[0017] In General Formula 1, R 1 to R 18 are each independently selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group. L 1 to L 3 are each independently selected from a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group; at least one of L 1 to L 3 is a group represented by General Formula 2 or General Formula 3:

[0018]

[0019] In General Formula 2 and General Formula 3, X 1 is selected from an oxygen atom, a sulfur atom, or N-R 25 ; R 19 to R 25 are each independently selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group; R 19 to R 22 may be linked to each other to form a ring structure; R 23 and R 24 may be linked to each other to form a ring structure, forming a cyclic structure; * indicates a bonding site.

[0020] ​(2) The compound according to the above (1), wherein the compound has a structure represented by the following General Formula 4,

[0021] In General Formula 4, R 2 ~R 17 and L 1 ~L 3 have the same meanings as those in General Formula 1.

[0022] (3) The compound according to the above (1), wherein R 2 ~R 7 is a hydrogen atom.

[0023] (4) The compound according to the above (1), wherein the group represented by General Formula 2 or General Formula 3 is a group represented by any one of the following General Formulas 5 to 13.

[0024] In General Formula 8, X 2 has the same meaning as that of X 1 in General Formula 3. In General Formulas 9 to 11, X 3 is an oxygen atom, a sulfur atom or N-R 26 ; R 26 is selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group; and * indicates a bonding position.

[0025] (5) The compound according to the above (4), wherein at least one of L 1 ~L 3 is a group represented by General Formula 2, which is a group represented by any one of General Formulas 5 to 7.

[0026] (6) The compound according to the above (1), wherein L 3 is a single bond.

[0027] (7) A light-emitting device which emits light using electric energy, at least an electron transport layer and a light-emitting layer being present between an anode and a cathode, wherein the electron transport layer contains the compound according to any one of the above (1) to (6).

[0028] (8) The light-emitting device according to the above (7), wherein the electron transport layer further contains an alkali metal atom, a rare earth metal atom or a copper group atom.

[0029] (9) A light-emitting device which emits light using electric energy, at least a charge generation layer and a light-emitting layer being present between an anode and a cathode, wherein the charge generation layer contains the compound according to any one of (1) to (6).

[0030] (10) The light-emitting device according to (9) above, wherein the charge generation layer further contains a phenanthroline derivative.

[0031] (11) The light-emitting device according to (9) above, wherein the charge generation layer further contains an alkali metal atom, a rare earth metal atom, or a copper group atom.

[0032] (12) The light-emitting device according to (11) above, wherein the alkali metal atom is a Li atom.

[0033] (13) The light-emitting device according to (11) above, wherein the rare earth metal atom is a Yb atom.

[0034] (14) A light-emitting device that emits light using electric energy, which has at least an electron injection layer and a light-emitting layer between an anode and a cathode, wherein the electron injection layer contains a compound according to any one of (1) to (6) above.

[0035] (15) The light-emitting device according to (14) above, wherein the electron injection layer further contains an alkali metal atom, a rare earth metal atom, or a copper group atom.

[0036] (16) A display device that uses a light-emitting device containing a compound according to any one of (1) to (6) above.

[0037] (17) An electronic device that uses a light-emitting device containing a compound according to any one of (1) to (6) above.

[0038] (18) An illuminating device that uses a light-emitting device containing a compound according to any one of (1) to (6) above.

[0039] The present application can provide an OLED device that improves both light-emitting efficiency and durability. DETAILED DESCRIPTION

[0040] The following describes specific embodiments of the compound, light-emitting device, display device, electronic device, and illuminating device provided by the present application in detail. However, the present application is not limited to the following embodiments, and the embodiments can be modified as desired and for the intended use.

[0041] First, the compound having the structure shown in General Formula 1 provided by the present application is described in detail.

[0042]

General Formula 1

[0043] The general formula 1 includes a phenanthroline functional group, which is a functional group that connects two nitrogen-containing aromatic groups in a condensed ring manner, and this functional group can form a ligand with a metal more favorably than a single nitrogen-containing aromatic group or two nitrogen-containing aromatic groups spaced apart by a single bond or the like, thereby further improving device performance. 1 ~R 18 Each is independently selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group; L 1 ~L 3 Each is independently selected from a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group; at least one of the L 1 ~L 3 is a group represented by the following general formula 2 or general formula 3:

[0044] In the general formula 2 and general formula 3, X 1 is selected from an oxygen atom, a sulfur atom, or N-R 25 . R 19 ~R 25 Each is independently selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group; R 19 ~R 22 may be linked to each other to form a ring structure. R 23 and R 24 may be linked to each other to form a ring structure; * indicates a bonding site.

[0045] The hydrogen atom in all the above substituents can also be a deuterium atom. The same explanation is applied to the substituents, compounds, or parts of the structures involved in the following description.

[0046] The unsubstituted in the above "substituted or unsubstituted" refers to a case of bonding with a hydrogen atom or a deuterium atom. The same explanation is applied to "substituted or unsubstituted" in the compounds or parts of the structures involved in the following description.

[0047] The aryl group includes, for example, an aromatic group such as a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthryl group, an anthryl group, a benzophenanthryl group, a benzanthryl group, a pyrenyl group, a fluoranthenyl group, a triphenylenyl group, a benzofluoranthenyl group, a dibenzanthryl group, a perylenyl group, or a spirobicyclopentadecane group, and the like. The number of ring-forming atoms is not particularly limited, and is preferably in the range of 6 or more and 40 or less, more preferably in the range of 6 or more and 30 or less. Among them, a phenyl group is preferred.

[0048] The arylene group includes, for example, a phenylene group, a biphenylene group, a terphenylene group, a naphthylene group, a fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrylene group, an anthrylene group, a benzophenanthrylene group, a benzanthrylene group, a The arylene group includes, for example, a phenylene group, a biphenylene group, a pyrenylene group, a chrysenylene group, a triphenylene group, a benzochrysenylene group, a dibenzanthracenylene group, a pyrenylene group, or a spirobisoxylenyl group, and the like. The divalent bond of the arylene group is connected to the same conjugated system. The number of ring-forming atoms is not particularly limited, and is preferably in the range of 6 or more and 40 or less, more preferably in the range of 6 or more and 30 or less. Among them, a phenylene group or a biphenylene group is preferable.

[0049] The heteroarylene group includes, for example, a pyridylene group, a furanylene group, a thienylene group, a quinolylene group, an isoquinolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a naphthridinylene group, a cinnolinylene group, a phthalazinylene group, a quinoxalylene group, a quinazolylene group, a benzofuranylene group, a benzothienylene group, an indolylene group, a dibenzofuranylene group, a dibenzothienylene group, a carbazolylene group, a benzocarbazolylene group, an indolocarbazolylene group, a benzofuranocarbazolylene group, a benzothienocarbazolylene group, a dihydroindenocarbazolylene group, a benzquinolylene group, an acridinylene group, a dibenzoacridinylene group, a benzimidazolylene group, an imidazopyridinylene group, a benzoxazolylene group, a benzothiazolylene group, or a phenanthroline group, and the like, which have 1 or more non-carbon atoms in the ring. The naphthridinylene group means any one of a 1,5-naphthridinylene group, a 1,6-naphthridinylene group, a 1,7-naphthridinylene group, a 1,8-naphthridinylene group, a 2,6-naphthridinylene group, or a 2,7-naphthridinylene group. The divalent bond of the heteroarylene group is connected to the same conjugated system. The number of ring-forming atoms is not particularly limited, and is preferably in the range of 5 or more and 40 or less, more preferably in the range of 5 or more and 30 or less.

[0050] The alkyl group includes, for example, a methyl group, an ethyl group, a n-propyl group, an i-propyl group, a n-butyl group, a sec-butyl group, a t-butyl group, and the like, which are saturated aliphatic hydrocarbon groups. The number of carbon atoms of the alkyl group is not particularly limited, but from the viewpoint of ease of acquisition and cost, it is preferably in the range of 1 or more and 20 or less, more preferably in the range of 1 or more and 8 or less. The number of carbon atoms includes the number of carbon atoms contained in the substituents bonded to the alkyl group, and the same explanation is applied to the number of carbon atoms of other groups in the present specification.

[0051] The cycloalkyl group includes, for example, a cyclopropyl group, a cyclohexyl group, a norbornyl group, an adamantyl group, and the like, which are saturated aliphatic cyclic hydrocarbon groups, and can have a substituent or can not have a substituent. The number of ring-forming carbon atoms is not particularly limited, and is preferably in the range of 3 or more and 20 or less.

[0052] The alkylthio group is a group in which the oxygen atom of the ether bond of the alkoxy group is replaced with a sulfur atom. The alkylthio group can have a substituent or can not have a substituent. The number of carbon atoms of the alkylthio group is not particularly limited, but is preferably in the range of 1 or more and 20 or less.

[0053] The aryl ether group refers to a functional group bonded to an aromatic hydrocarbon group via an ether bond, and can have a substituent or can not have a substituent. The number of carbon atoms of the aryl ether group is not particularly limited, but is preferably in the range of 6 or more and 40 or less.

[0054] The aryl sulfide group refers to a functional group in which the oxygen atom of the ether bond of the aryl ether group is replaced with a sulfur atom, and can have a substituent or can not have a substituent. The number of carbon atoms of the aryl sulfide group is not particularly limited, but is preferably in the range of 6 or more and 40 or less.

[0055] The halogen refers to fluorine, chlorine, bromine, or iodine.

[0056] The acyl group includes, for example, a carbonyl group bonded to an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, or a heteroaryl group, and can have a substituent or can not have a substituent. The number of carbon atoms of the acyl group is not particularly limited, but is preferably 2 or more and 40 or less, and more preferably 2 or more and 30 or less.

[0057] The ester group includes, for example, a functional group bonded via an ester bond, such as an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and can have a substituent or can not have a substituent. The number of carbon atoms of the ester group is not particularly limited, but is preferably in the range of 1 or more and 20 or less. Specifically, examples include a methyl ester group such as a methoxycarbonyl group, an ethyl ester group such as an ethoxycarbonyl group, a propyl ester group such as a propyloxycarbonyl group, a butyl ester group such as a butyloxycarbonyl group, an isopropyl group such as an isopropoxymethoxycarbonyl group, a cyclohexyl ester group such as a cyclohexyloxycarbonyl group, and a phenyl ester group such as a phenoxycarbonyl group.

[0058] The amido group includes, for example, a functional group bonded via an amido bond, such as an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and can have a substituent or can not have a substituent. The number of carbon atoms of the amido group is not particularly limited, but is preferably in the range of 1 or more and 20 or less. Specifically, examples include a methyl amido group, an ethyl amido group, a propyl amido group, a butyl amido group, an isopropyl amido group, a hexyl amido group, and a phenyl amido group.

[0059] The sulfonyl group refers to a functional group in which, for example, an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group is bonded via an -S(=O)2- bond, and can have a substituent or can not have a substituent. The number of carbon atoms in the sulfonyl group is not particularly limited, but is preferably in the range of 1 or more and 20 or less.

[0060] The sulfonate group includes, for example, a functional group bonded via a sulfonate bond, such as an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and can have a substituent or can not have a substituent. The sulfonate bond is an ester bond in which the carbonyl moiety, that is, -C(=O)- is replaced with a sulfonyl group -S(=O)2-. The number of carbon atoms of the sulfonate group is not particularly limited, but is preferably in the range of 1 or more and 20 or less.

[0061] The sulfonamide group includes, for example, a functional group such as an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, which is bonded by a sulfonamide bond, and can have a substituent or can not have a substituent. Here, the sulfonamide bond is an amide bond in which the carbonyl moiety (i.e., -C(=O)-) of the amide bond is substituted with a sulfonyl group (-S(=O)2-). The number of carbon atoms of the sulfonamide group is not particularly limited, but is preferably in the range of 1 or more and 20 or less.

[0062] The amino group can have a substituent or can not have a substituent. The number of carbon atoms in the amino group is not particularly limited, but is preferably in the range of 2 or more and 50 or less, more preferably in the range of 6 or more and 40 or less, and further preferably in the range of 6 or more and 30 or less.

[0063] The silicon group refers to a functional group in which a substituted or unsubstituted silicon atom is bonded, and includes, for example, an alkylsilyl group such as a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a propyldimethylsilyl group, or a vinyl dimethylsilyl group; an arylsilyl group such as a phenyldimethylsilyl group, a t-butyldiphenylsilyl group, a triphenylsilyl group, or a triphenanthrylsilyl group. The silicon group can have a substituent or can not have a substituent. The number of carbon atoms of the silicon group is not particularly limited, but is preferably in the range of 1 or more and 30 or less.

[0064] The siloxane group refers to a silicon compound group formed by an ether bond, and includes, for example, a trimethylsiloxane group. The siloxane group can have a substituent or can not have a substituent.

[0065] The boron group can have a substituent or can not have a substituent.

[0066] Generally, a compound containing a phenanthroline structure and a fluoranthene structure has a problem in that film stability and handleability are reduced due to high crystallinity. However, in the compound of general formula 1 according to the present application, L 1 ~ L 3 is selected from a compound represented by general formula 2 or general formula 3. The two groups to which general formula 2 or general formula 3 is attached exist in an ortho position, and thus the intermolecular interaction between the high-crystalline phenanthroline structure and the fluoranthene structure is inhibited, thereby preventing the crystallinity of the molecule from being excessively increased.

[0067] Further, it is preferable that the compound represented by general formula 1 has a structure represented by general formula 4 below, and the compound has excellent film stability and handleability, thereby enhancing the device lifetime.

[0068] In general formula 4, R 2 ~ R 17 and L 1 ~ L 3the same definition as X

[0069] From the viewpoint of ease of obtaining the compound, R 2 ~R 17 each independently selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group; R 2 ~R 7 When substituted, these sites conjugate with the electron pair of nitrogen, thereby weakening the electron density of nitrogen and reducing the coordination activity of nitrogen, which in turn reduces the stability of the ligand formed with the metal and lowers the overall performance of the device. Therefore, R 2 ~R 7 A hydrogen atom is preferred. In addition, X 1 is preferably an oxygen atom or a sulfur atom. In this case, the increase in the electron density of the compound leads to further improvement in the coordination property with the metal atom, thereby reducing the voltage of the device.

[0070] Further, the group represented by the general formula 2 or the general formula 3 is preferably represented by any one of the following general formulae 5 to 13:

[0071] In the above general formula 8, X 2 has the same definition as X 1 in the above general formula 3; in general formulae 9 to 11, X 3 is an oxygen atom, a sulfur atom, or N-R 26 ; R 26 is selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group, and the use of these atoms can enhance the coordination property of the molecule and reduce the voltage of the device, but can also lead to a slightly higher refractive index than other preferred structures, thereby reducing the efficiency of the device to some extent; * indicates the bonding site.

[0072] Preferably, at least one of L 1 ~L 3 is a group represented by the general formula 2. In order to obtain better film formation performance and improve the lifetime, the group represented by the general formula 2 is preferably any one of the above general formulae 5 to 13, and more preferably any one of the above general formulae 5 to 7, in consideration of the comprehensive improvement in voltage and efficiency.

[0073] From the viewpoint of ease of obtaining the compound and the suppression of excessive crystallinity to improve the lifetime, L 3 is preferably a single bond.

[0074] From the viewpoint of suppressing crystallization and improving stability of the film and improving the life, the molecular weight of the compound represented by General Formula 1 is preferably 450 or greater, and further preferably 470 or greater. On the other hand, from the viewpoint of improving the processability of sublimation purification and vapor deposition, the molecular weight of the compound represented by General Formula 1 is preferably 750 or less, and further preferably 700 or less.

[0075] In all of the above groups, the substituents at the time of substitution are preferably an alkyl group, a cycloalkyl group, a heteroaliphatic cyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, a halogen, a cyano group, an aldehyde group, an acyl group, a carboxyl group, an ester group, an amide group, a sulfonyl group, a sulfonate ester group, a sulfonamide group, an amino group, a nitro group, a silicon group, a siloxane group, a boron group, or an oxo group. Furthermore, the above substituents can be further substituted with the above substituents.

[0076] As the alkyl group, the cycloalkyl group, and the aryl group, the above-mentioned groups can be mentioned.

[0077] The heteroaliphatic cyclic group includes, for example, a pyran ring, a piperidine ring, or a cyclic amide, and the like, and has a carbon atom other than the ring. The number of ring-forming atoms is not particularly limited, and is preferably in the range of 3 or greater and 20 or less.

[0078] The alkenyl group includes, for example, an ethylene group, an allyl group, or a butadiene group, and the like, and is an unsaturated aliphatic hydrocarbon group containing a double bond. The alkenyl group can have a substituent or can not have a substituent. The number of carbon atoms of the alkenyl group is not particularly limited, and is preferably in the range of 2 or greater and 20 or less.

[0079] The cycloalkenyl group includes, for example, a cyclopentenyl group, a cyclopentadienyl group, or a cyclohexenyl group, and the like, and is an unsaturated aliphatic cyclic hydrocarbon group containing a double bond. The cycloalkenyl group can have a substituent or can not have a substituent.

[0080] The alkynyl group includes, for example, an ethynyl group, and the like, and is an unsaturated aliphatic hydrocarbon group containing a triple bond. The alkynyl group can have a substituent or can not have a substituent. The number of carbon atoms of the alkynyl group is not particularly limited, and is preferably in the range of 2 or greater and 20 or less.

[0081] The heteroaryl groups include, for example, pyridinyl, furanyl, thiopheneyl, quinolinyl, isoquinolinyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, naphridinyl, cenolinyl, phthalazinyl, quinoxalyl, quinazolyl, benzofuranyl, benzothiopheneyl, indolyl, dibenzofuranyl, dibenzothiopheneyl, carbazoleyl, benzocarbazoleyl, carbonyl, indolocarbazoleyl, benzofurancarbazoleyl, benzothiophenecarbazoleyl, dihydroindocarbazoleyl, benzoquinolinyl, acridineyl, dibenzoacridyl, benzoimidazolyl, imidazopyridyl, benzooxazolyl, benzothiazolyl, or phenantholinyl, etc., representing cyclic aromatic groups having one or more non-carbon atoms within the ring. The naphthidyl group refers to any one of 1,5-naphthidyl, 1,6-naphthidyl, 1,7-naphthidyl, 1,8-naphthidyl, 2,6-naphthidyl, or 2,7-naphthidyl. The number of cyclic atoms is not particularly limited, but is preferably in the range of 5 to 40, more preferably in the range of 5 to 30. Pyridyl is particularly preferred.

[0082] The alkoxy group includes, for example, alkyl groups bonded to oxygen, such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, or tert-butoxy. The number of carbon atoms in the alkoxy group is not particularly limited, but considering ease of acquisition and cost, it is generally preferred to have 1 or more and 20 or less, more preferably 1 or more and 8 or less.

[0083] The alkylthio group is a group in which the oxygen atom of the ether bond of an alkoxy group is replaced by a sulfur atom. The alkylthio group may or may not have substituents. There is no particular limitation on the number of carbon atoms in the alkylthio group, but it is preferably in the range of 1 to 20.

[0084] The aryl ether group refers to a functional group such as phenoxy group that is bonded to an aromatic hydrocarbon group via an ether bond. It may or may not have substituents. There is no particular limitation on the number of carbon atoms in the aryl ether group, but it is preferably in the range of 6 or more and 40 or less.

[0085] The aryl thioether group refers to a functional group in which the oxygen atom of the ether bond in an aryl ether group is replaced by a sulfur atom. It may or may not have substituents. There is no particular limitation on the number of carbon atoms in the aryl thioether group, but it is preferably in the range of 6 or more and 40 or less.

[0086] Halogens refer to fluorine, chlorine, bromine, or iodine.

[0087] The acyl group includes functional groups such as acetyl, propionyl, benzoyl, or acryloyl, which are carbonyl groups bonded to alkyl, cycloalkyl, alkenyl, alkynyl, aryl, or heteroaryl groups, and may or may not have substituents. The number of carbon atoms in the acyl group is not particularly limited, but is preferably 2 or more and 40 or less, more preferably 2 or more and 30 or less.

[0088] The ester group includes a functional group bonded by an ester bond, such as an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and can have a substituent or can not have a substituent. The number of carbon atoms in the ester group is not particularly limited, but is preferably in the range of 1 or more and 20 or less. Specifically, examples include a methyl ester group such as a methoxycarbonyl group, an ethyl ester group such as an ethoxycarbonyl group, a propyl ester group such as a propyloxycarbonyl group, a butyl ester group such as a butyloxycarbonyl group, an isopropyl group such as an isopropoxymethoxycarbonyl group, a cyclohexyl ester group such as a cyclohexyloxycarbonyl group, and a phenyl ester group such as a phenoxycarbonyl group.

[0089] The amide group includes a functional group bonded by an amide bond, such as an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and can have a substituent or can not have a substituent. The number of carbon atoms in the amide group is not particularly limited, but is preferably in the range of 1 or more and 20 or less. Specifically, examples include a methyl amide group, an ethyl amide group, a propyl amide group, a butyl amide group, an isopropyl amide group, a hexyl amide group, and a phenyl amide group.

[0090] The sulfonyl group refers to a functional group bonded by a -S(=O)2- bond, such as an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and can have a substituent or can not have a substituent. The number of carbon atoms in the sulfonyl group is not particularly limited, but is preferably in the range of 1 or more and 20 or less.

[0091] The sulfonate group includes a functional group bonded by a sulfonate bond, such as an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and can have a substituent or can not have a substituent. The sulfonate bond is a carbonyl moiety, that is, a -C(=O)- substituted with a sulfonyl group -S(=O)2-. The number of carbon atoms in the sulfonate group is not particularly limited, but is preferably in the range of 1 or more and 20 or less.

[0092] The sulfonamide group includes a functional group bonded by a sulfonamide bond, such as an alkyl group, a cycloalkyl group, an aryl group, or a heteroaryl group, and can have a substituent or can not have a substituent. Here, the sulfonamide bond is an amide bond in which the carbonyl moiety (that is, -C(=O)-) is substituted with a sulfonyl group (-S(=O)2-). The number of carbon atoms in the sulfonamide group is not particularly limited, but is preferably in the range of 1 or more and 20 or less.

[0093] The amino group can have a substituent or can not have a substituent. The number of carbon atoms in the amino group is not particularly limited, but is preferably in the range of 2 or more and 50 or less, more preferably in the range of 6 or more and 40 or less, and further preferably in the range of 6 or more and 30 or less.

[0094] The silicon group refers to a functional group having a substituted or unsubstituted silicon atom bonded thereto, and includes, for example, alkylsilyl groups such as trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, propyldimethylsilyl, or vinyldimethylsilyl; phenyldimethylsilyl; t-butyldiphenylsilyl; triphenylsilyl; or triphenanthrylsilyl. The silicon group can have a substituent or can not have a substituent. The number of carbon atoms of the silicon group is not particularly limited, but is preferably in the range of 1 or more and 30 or less.

[0095] The siloxane group refers to a silicon compound group formed by an ether bond, and includes, for example, trimethylsiloxane group. The siloxane group can have a substituent or can not have a substituent.

[0096] The boron group can have a substituent or can not have a substituent.

[0097] The compound represented by General Formula 1 can be exemplified by the compounds shown below. The following are merely examples, and compounds other than the following examples are also within the preferable range as long as they satisfy General Formula 1.

[0098] The compound represented by General Formula 1 can be synthesized by a publicly known synthesis method. Examples of the synthesis method include, but are not limited to, a coupling reaction between a phenanthroline derivative and a fluoranthene derivative.

[0099] The compound represented by General Formula 1 is preferably used for any layer of a light-emitting device. As described later, the compound represented by General Formula 1 is suitably used for a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, a charge generation layer, an electron injection layer, a protective layer (a cover layer) of an electrode, and the like in a light-emitting device. Use of the material represented by General Formula 1 in any layer of a light-emitting device can provide a light-emitting device with excellent emission efficiency and long lifetime.

[0100] Light-emitting device

[0101] The present application is implemented in the form of a light-emitting device including an anode and a cathode, and a functional layer between the anode and the cathode. The functional layer can emit light by electric energy. Such a light-emitting device is hereinafter referred to as an "OLED device".

[0102] The functional layers between the anode and the cathode in the OLED device, in addition to the light-emitting layer alone, can also include the following stack layer structures: 1) light-emitting layer / electron transport layer, 2) hole transport layer / light-emitting layer, 3) hole transport layer / light-emitting layer / electron transport layer, 4) hole injection layer / hole transport layer / light-emitting layer / electron transport layer, 5) hole transport layer / light-emitting layer / electron transport layer / electron injection layer, 6) hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer, or 7) hole injection layer / hole transport layer / light-emitting layer / hole blocking layer / electron transport layer / electron injection layer, etc.

[0103] In addition, the above-mentioned stack layer structures can also be connected by an intermediate layer into multiple stack layer structures, which is referred to as a stacked device. The intermediate layer can also be referred to as an intermediate electrode, an intermediate conductive layer, a charge generation layer, an electron extraction layer, a connecting layer, or an intermediate insulating layer, etc. The intermediate layer can use known materials. The stacked device can have the following examples: 8) hole transport layer / light-emitting layer / electron transport layer / charge generation layer / hole transport layer / light-emitting layer / electron transport layer, or 9) hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / charge generation layer / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer, etc. The examples are characterized in that there is an intermediate layer between the anode and the cathode, which is often referred to as a charge generation layer.

[0104] In addition, each of the above-mentioned layers can be a single layer or multiple layers, and can be doped. In particular, the above-mentioned electron injection layer and charge generation layer are preferably metal-doped layers, which can improve the electron transport capability and the ability to inject electrons into other adjacent layers. In addition, in addition to the above-mentioned layers, a protective layer (cover layer) can also be provided, which can further improve the light-emitting efficiency through optical interference effects.

[0105] The compound represented by general formula 1 can be used in each of the above-mentioned layers in the OLED device, but is particularly preferably used in an electron transport layer, a charge generation layer, or an electron injection layer. The OLED device implemented according to the present application is preferably listed as follows: 1. At least having an electron transport layer and a light-emitting layer between the anode and the cathode, the electron transport layer containing the compound represented by general formula 1; 2. At least having a charge generation layer and a light-emitting layer between the anode and the cathode, and the charge generation layer containing the compound represented by general formula 1; or 3. At least having an electron injection layer and a light-emitting layer between the anode and the cathode, the electron injection layer containing the compound represented by general formula 1.

[0106] In the OLED device implemented according to the present application, the anode and the cathode have the function of providing sufficient current for the light-emission of the device, and preferably at least one of them is transparent or semi-transparent, so as to facilitate the light emission out of the device.

[0107] Substrate

[0108] In order to maintain the mechanical strength of the OLED device, it is preferable to form the OLED device on a substrate. As the substrate, a glass substrate such as soda lime glass or alkali-free glass, or a plastic substrate, or the like can be used. The thickness of the glass substrate should be sufficient to maintain the mechanical strength, and needs to be 0.5 mm or more. As the material of the glass, an alkali-free glass which has a small amount of ions eluted from the glass is preferable. In addition, a soda lime glass coated with a barrier coating layer of SiO2or the like is also commercially available, and can be used.

[0109] Anode

[0110] The material for the anode is preferably a material capable of efficiently injecting holes into the organic layer. In addition, in order to emit light to the outside of the device, a material which is transparent or semi-transparent is preferable. Examples of the material for the anode include: electrically conductive metal oxides such as zinc oxide, tin oxide, indium oxide, indium tin oxide (ITO), or indium zinc oxide (IZO), metals such as gold, silver, or chromium, inorganic electrically conductive substances such as copper iodide or copper sulfide, electrically conductive polymers such as polythiophene, polypyrrole, or polyaniline, and the like. Among these, ITO glass or Nesa glass is preferable. These electrode materials can be used alone, or a plurality of materials can be stacked or mixed.

[0111] Cathode

[0112] The material for the cathode is not particularly limited as long as it is capable of efficiently injecting electrons into the light-emitting layer. The material for the cathode can be exemplified by: metals such as platinum, gold, silver, copper, iron, tin, aluminum, or indium, or alloys or multi-layer stacked materials of these metals and low work function metals such as lithium, sodium, potassium, calcium, or magnesium. Among these, from the aspects of resistance, ease of film formation, film stability, and light-emitting efficiency, and the like, aluminum, silver, magnesium are preferable as the main component, and from the viewpoint of easier injection of electrons to the electron transport layer, the electron injection layer, it is more preferable to be composed of magnesium and silver.

[0113] Protective layer

[0114] In order to protect the cathode, it is preferable to stack a protective layer, which can also be referred to as a cover layer, on the cathode. The material constituting the protective layer is not particularly limited, and can be exemplified by: metals such as platinum, gold, silver, copper, iron, tin, aluminum, or indium, alloys using these metals, inorganic substances such as silicon dioxide, titanium dioxide, or silicon nitride, organic polymer compounds such as polyvinyl alcohol, polyvinyl chloride, hydrocarbon-based polymer compounds, and the like. In addition, the compound represented by General Formula 1 can also be used as the material of the protective layer. However, when the OLED device is a device structure in which light is extracted from the cathode side (top emission structure), the material of the protective layer is preferably a material having light transmittance in the visible light region.

[0115] Hole injection layer

[0116] The hole injection layer is a layer interposed between the anode and the hole transport layer. The hole injection layer can be a single layer or a multi-layer stack. When the hole injection layer is present between the hole transport layer and the anode, not only lower driving voltage and longer lifetime can be achieved, but also the carrier balance of the device can be improved and the luminous efficiency can be increased, and thus the use of this layer is preferred.

[0117] The material of the hole injection layer can use known materials, for example, a benzidine derivative, a starburst arylamine material group, a triarylamine derivative, a biscarbazole derivative, a pyrazoline derivative, a diphenyl ethylene compound, a fluorene compound, a hydrazine compound, a benzofuran derivative, a thiophene derivative, an oxadiazole derivative, a phthalocyanine derivative, or a heterocyclic compound such as a porphyrin derivative, and a derivative of the above-mentioned compounds, or a high molecular material having a polycarbonate, a styrene derivative, a polythiophene, a polyaniline, a polyfluorene, a polyvinylcarbazole, a polysilane, etc. in the side chain of the above-mentioned compounds. From the viewpoint of efficiently injecting and transporting holes from the anode to the hole transport layer, a benzidine derivative, a starburst arylamine material, or a fluorene compound is preferably used.

[0118] These materials can be used alone or in combination of two or more, and in addition, the hole injection layer can be formed by stacking a plurality of materials. Further, in order to more significantly obtain the above-mentioned effects, the hole injection layer is more preferably composed of only an acceptor compound, or the above-mentioned hole injection material is doped with an acceptor compound. The acceptor compound refers to the material of the layer when used as a single layer film, or the dopant when used as a dopant. When these materials are used, the conductivity of the hole injection layer is improved, which is helpful to further reduce the driving voltage of the device, and further improve the luminous efficiency and the lifetime.

[0119] The acceptor compound can use known materials, for example, a metal chloride or a metal oxide such as molybdenum oxide, a charge transfer ligand, or an organic compound having a nitro group, a cyano group, a halogen, or a trifluoromethyl group in the molecule, a quinone compound, an anhydride compound, or a fullerene, etc. Among them, a metal oxide or a cyano-containing compound is preferred because they are easy to handle and easy to evaporate, thus easy to obtain the above-mentioned effects. In the case where the hole injection layer is composed of only an acceptor compound, or in the case where the hole injection layer is doped with an acceptor compound, the hole injection layer can be a single layer, or can be stacked in multiple layers.

[0120] Hole transport layer

[0121] The hole transport layer is a layer that transports holes injected from the anode to the light-emitting layer. The hole transport layer can be a single layer, or can be composed of a plurality of layers stacked.

[0122] The material used in the above-mentioned hole injection layer can also be used as a hole transport layer material. From the viewpoint of efficiently injecting and transporting holes to the light-emitting layer, a triarylamine derivative or a benzidine derivative is preferred.

[0123] Emissive layer

[0124] The light-emitting layer can be a single layer or multiple layers. The light-emitting layer is formed of a light-emitting material, which can be a mixture of a host material and a dopant material, a single host material, or a mixture of two types of host materials and one type of dopant material. That is, in the OLED device according to the present invention, in each light-emitting layer, only the host material or the dopant material may emit light, or both the host material and the dopant material may emit light. From the viewpoint of efficiently utilizing electrical energy and obtaining light with high color purity, the light-emitting layer is preferably a mixture of a host material and a dopant material. Furthermore, the host material and the dopant material can each be one type, or a combination of multiple types. The dopant material can be completely or partially contained in the host material. The dopant material can be layered or dispersed. The dopant material can control the color of the emitted light. From the viewpoint of suppressing concentration quenching, the amount of dopant material relative to the host material is preferably 30% by weight or less, more preferably 20% by weight or less. As for the doping method, it can be formed by co-evaporation with the host material, or it can be pre-mixed with the host material and then simultaneously evaporated.

[0125] The luminescent material can be any known material. For example, polymers such as anthracene or pyrene fused-ring derivatives, metal chelate hydroxy compounds such as tris(8-hydroxyquinoline)aluminum, bis(styrene) derivatives such as bis(styrene)anthracene or styrenebenzene derivatives, tetraphenylbutadiene derivatives, indene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, pyloridenone derivatives, cyclopentadiene derivatives, thiadiazopyridine derivatives, dibenzofuran derivatives, carbazole derivatives, indolecarbazole derivatives, poly(p-styrene) derivatives, poly(p-phenylene)benzene derivatives, or polythiophene derivatives are known as luminescent substances.

[0126] The host material in a luminescent material can be a single compound, a mixture of multiple compounds, or a stacked arrangement. The host material can be any known material without particular limitation, such as naphthalene, anthracene, phenanthrene, pyrene, etc. , naphthalene, anthracene, phenanthrene, pyrene, tetracene, triphenylene, perylene, fluoranthene, fluorene, or indene, and derivatives thereof, aromatic amine compounds such as N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diphenyl-1,1'-biphenyl- 1,1'-diamine, oxinoid compounds such as tris(8-quinolinolato)aluminum (III) chelated with a metal, or stilbene derivatives such as stilbene derivatives, tetraphenylbutadiene derivatives, indene derivatives, coumarin derivatives, oxadiazole derivatives, pyrrolopyridine derivatives, perinone derivatives, cyclopentadiene derivatives, pyrrolopyrrole derivatives, thiazolopyridine derivatives, dibenzofuran derivatives, carbazole derivatives, indolocarbazole derivatives, triazine derivatives, polystyrene derivatives, polyphenylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, or polythiophene derivatives, and the like. Among these, as the host material used in the light-emitting layer structure using triplet light (phosphorescence), oxinoid compounds chelated with a metal, dibenzofuran derivatives, dibenzothiophene derivatives, carbazole derivatives, indolocarbazole derivatives, triazine derivatives, or triphenylene derivatives, and the like are preferably used.

[0127] The dopant material contained in the light-emitting material can be exemplified by: compounds having an aromatic ring and derivatives thereof, compounds having a heteroaromatic ring and derivatives thereof, stilbene derivatives, Aldazine derivatives, pyrromethene derivatives, tetraphenylbutadiene derivatives, stilbene derivatives, aldazine derivatives, pyrromethene derivatives, diketopyrrolo[3,4-c]pyrrole derivatives, coumarin derivatives, oxazole derivatives, aromatic amine derivatives, metal ligands of all the above compounds, or compounds represented by the following general formula 14, and the like. Among these, the dopant material containing a diamine skeleton and the dopant material containing a fluoranthene skeleton can further improve the light-emitting efficiency, and the compound represented by the following general formula 14 can further improve the light-emitting efficiency and the lifetime.

[0128] In the general formula 14, each of the Za ring, the Zb ring, and the Zc ring is independently selected from a substituted or unsubstituted aromatic ring having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaromatic ring having 5 to 30 ring-forming atoms. 1 and Z 2 are each independently selected from an oxygen atom, an N-Ra (a nitrogen atom having a substituent Ra), or a sulfur atom. When Z 1 is N-Ra, the Ra can be combined with the Za ring or the Zb ring to form a ring, or can not form a ring. 2 is N-Ra, the Ra can be combined with the Zb ring or the Zc ring to form a ring, or can not form a ring. 1 and Z 2When A is N-Ra, each Rais independently selected from a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 ring-forming atoms, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms. In General Formula 14, Z 1 and Z 2 are each N-Ra, and Rais preferably a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms. In General Formula 14, Y is a boron atom, a phosphorus atom, Si-Rb (a silicon atom having a substituent Rb), P=O, or P=S. Rbis selected from a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroaryl group having 5 to 30 ring-forming atoms, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; preferably, Y is a boron atom. In all of the above groups, the substituents, when substituted, are preferably an alkyl group, a cycloalkyl group, a heteroalicyclyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, a halogen, a cyano group, an aldehyde group, an acyl group, a carboxyl group, an ester group, an amide group, a sulfonyl group, a sulfonate ester group, a sulfonamide group, an amino group, a nitro group, a silyl group, a siloxane group, a boron group, or an oxo group. Furthermore, these substituents can be further substituted with the above substituents.

[0129] As the alkyl group, cycloalkyl group, heteroalicyclyl group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, aryl group, heteroaryl group, alkylthio group, aryloxy group, arylthio group, halogen, acyl group, ester group, amide group, sulfonyl group, sulfonate ester group, sulfonamide group, amino group, silyl group, siloxane group, and boron group, the groups exemplified above as substituents can be cited.

[0130] As the compound represented by General Formula 14, the following examples can be cited.

[0131] In the OLED device provided by the present application, the light-emitting layer preferably contains a material that can emit light from a triplet state.

[0132] The dopant material used when the light-emitting layer emits triplet light (phosphorescence) is preferably a metal complex containing at least one metal of iridium (Ir), ruthenium (Ru), palladium (Pd), platinum (Pt), osmium (Os), or rhenium (Re). The ligand constituting the metal complex is preferably a nitrogen-containing aromatic heterocycle such as a phenylpyridine skeleton, a phenylquinoline skeleton, or a carbene skeleton. However, the ligand is not limited to these, and an appropriate ligand can be selected based on the desired emission color, device performance, and relationship with the host material. Specifically, the following compounds can be cited: tris(2-phenylpyridine) iridium, tris{2-(2-thienyl)pyridine} iridium, tris{2-(2-benzothienyl)pyridine} iridium, tris(2-phenylbenzothiazole) iridium, tris(2-phenylbenzoxazole) iridium, trisbenzoquinoline iridium, bis(2-phenylpyridine)(acetylacetone) iridium, bis{2-(2-thienyl)pyridine} iridium, bis{2-(2-benzothienyl)pyridine}(acetylacetone) iridium, bis(2-phenylbenzothiazole)(acetylacetone) iridium, bis(2-phenylbenzoxazole)(acetylacetone) iridium, bisbenzoquinoline(acetylacetone) iridium, bis{2-(2,4-difluorophenyl)pyridine}(acetylacetone) iridium, tetraethylporphyrin platinum, {tris(difluorodioxoselenium trifluoroacetonato) mono(1,10-phenanthroline)} europium complex, {tris(difluorodioxoselenium trifluoroacetonato) mono(4,7-diphenyl-1,10-phenanthroline)} europium complex, {tris(1,3-diphenyl-1,3-propanedione) mono(1,10-phenanthroline)} europium complex, or tris(acetylacetone) terbium complex. In addition, it is also preferable to use the phosphorescent dopant material described in Japanese Patent Application Publication No. 2009-130141. The iridium ligand or platinum ligand is preferable, and the emission efficiency can be further improved.

[0133] The triplet light-emitting material used as the dopant material described above can be contained in the light-emitting layer alone or in a mixture of two or more kinds. When two or more kinds of triplet light-emitting materials are used, the total weight of the dopant material is preferably 30% by mass or less, more preferably 20% by mass or less, relative to the host material.

[0134] The preferred host material and dopant material in the triplet light-emitting system are not particularly limited, and specific examples include the following compounds:

[0135] In addition, the light-emitting layer preferably contains a thermally activated delayed fluorescence material. The thermally activated delayed fluorescence material is explained in pages 87 to 103 of "The Most Advanced Organic EL" (edited by Asada Chiyoka and Fujimoto Hiroshi, published by CMC Publishing). In this document, the thermally activated delayed fluorescence (TADF) is described as follows: this invention improves the transfer probability of the reverse energy transfer from the excited triplet state to the excited singlet state, which originally has a very low transfer probability, by bringing the energy levels of the excited singlet state and the excited triplet state of the fluorescent material close to each other. Further, in Fig. 5 of this document, the generation mechanism of delayed fluorescence is explained. Delayed fluorescence emission can be confirmed by a transient PL (Photo Luminescence) test.

[0136] The thermally activated delayed fluorescence material is also commonly referred to as a TADF material. The thermally activated delayed fluorescence material can be a single material that exhibits thermally activated delayed fluorescence, or a plurality of materials that exhibit thermally activated delayed fluorescence. When a plurality of materials is used, they can be used as a mixture, or can be used by stacking layers made of each material. As the thermally activated delayed fluorescence material, known materials can be used, including but not limited to benzyl cyanide derivatives, triazine derivatives, disulfoxide derivatives, carbazole derivatives, indolocarbazole derivatives, dihydrophenazine derivatives, thiazole derivatives, or oxadiazole derivatives.

[0137] A device in a light-emitting layer containing a TADF material preferably has a structure in which the light-emitting layer also contains a fluorescent dopant material. This is because, in the case where the singlet exciton is received by the fluorescent dopant material after the triplet exciton is converted to the singlet exciton by the TADF material, higher light-emitting efficiency and longer life can be achieved.

[0138] Electron transport layer

[0139] In the present application, the electron transport layer is a layer that further transports electrons injected from the cathode. A good electron transport layer has high electron injection efficiency and can efficiently transport the injected electrons. Therefore, the material constituting the electron transport layer is preferably a substance having high electron affinity, high electron mobility, excellent stability, and a low tendency to trap impurities during manufacture and use. In particular, when the thickness of the film is relatively thick, low-molecular-weight compounds tend to crystallize, resulting in deterioration of the film quality, and in order to maintain stable film quality, a compound having a molecular weight of 400 or more is preferred. However, when the balance between the transport of holes and electrons is taken into consideration, if the holes that do not recombine during the flow from the anode to the cathode can be effectively prevented by the electron transport material, the effect of the electron transport layer on the improvement of the emission efficiency can reach the same level as when the electron transport layer is made of a material having high electron transport ability, even if the material has not so high electron transport ability. Therefore, the electron transport layer in the present application includes a hole blocking layer that can effectively block the movement of holes, and the hole blocking layer and the electron transport layer can be used separately or can be configured by stacking layers of various materials.

[0140] As the electron transport material used in the electron transport layer, known materials can be used, and various metal ligands such as fused polycyclic aromatic derivatives, styryl aromatic ring derivatives, quinone derivatives, phosphorus oxide derivatives, hydroxyquinoline ligands, benzo-hydroxyquinoline ligands, oxazole ligands, azomethine ligands, tropolone metal ligands, or flavonol metal ligands can be exemplified. In order to further reduce the driving voltage and obtain a higher efficient emission, a heteroaromatic ring structure composed of carbon, hydrogen, nitrogen, oxygen, silicon, or phosphorus elements and containing electron-accepting nitrogen is preferred.

[0141] The electron-accepting nitrogen refers to a nitrogen atom that forms a multiple bond with adjacent atoms. Since the nitrogen atom has high electronegativity, the multiple bond has the property of accepting electrons. Therefore, an aromatic heterocycle containing electron-accepting nitrogen has high electron affinity. The electron transport material having electron-accepting nitrogen can easily receive electrons from the cathode having high electron affinity, and can be driven at a lower voltage. In addition, more electrons can be supplied to the light-emitting layer, increasing the probability of recombination, thereby further improving the emission efficiency.

[0142] The heteroaromatic ring containing electron-accepting nitrogen includes, but is not limited to, a triazine ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a quinoline ring, a quinoxaline ring, a quinazoline ring, a naphthylidine ring, a pyrimidopyrimidine ring, a benzoquinoline ring, a phenanthroline ring, an imidazole ring, an oxazole ring, an oxadiazole ring, a triazole ring, a thiazole ring, a thiadiazole ring, a benzoxazole ring, a benzothiazole ring, a benzimidazole ring, or an imidazophenanthroline ring, etc.

[0143] Examples of the compound having a heteroaromatic ring structure containing an electron-accepting nitrogen include, but are not limited to, pyridine derivatives, triazine derivatives, quinazoline derivatives, pyrimidine derivatives, benzimidazole derivatives, benzoxazole derivatives, benzothiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, quinoline derivatives, benzoquinoline derivatives, oligopyridine derivatives, naphthylidine derivatives, and the like. Among them, from the viewpoint of electron-transporting ability, it is preferable to use imidazole derivatives, oxadiazole derivatives, triazole derivatives, triazine derivatives, pyrimidine derivatives, phenanthroline derivatives, benzoquinoline derivatives, bipyridine derivatives, terpyridine derivatives, or naphthylidine derivatives.

[0144] Further, it is preferable that the derivative has a fused polycyclic aromatic skeleton, because such a structure can increase the glass transition temperature and increase the electron mobility, thereby further reducing the driving voltage of the OLED device. Further, in view of further improving the lifetime of the device, ease of synthesis, and availability of raw materials, the fused polycyclic aromatic skeleton can be a fluoranthene skeleton, an anthracene skeleton, a pyrene skeleton, or a phenanthroline skeleton.

[0145] The preferable electron-transporting material is not particularly limited, and includes, but is not limited to, the following materials:

[0146] In addition, the compound represented by General Formula 1 preferably has high electron-transporting properties, and is an excellent material as an electron-transporting layer.

[0147] The above-described electron-transporting material can be used alone, or two or more of the above-described electron-transporting materials can be mixed, or one or more other electron-transporting materials can be mixed with the above-described electron-transporting material.

[0148] The electron-transporting layer can contain a donor material. The donor material is a type of compound that improves the electron injection barrier, promotes the injection of electrons from the cathode or the electron-injecting layer into the electron-transporting layer, and further improves the conductivity of the electron-transporting layer.

[0149] From the viewpoint of lowering the work function and improving the electron-transporting properties, the donor material preferably contains an alkali metal atom, an alkaline earth metal atom, a rare earth metal atom, or a copper group atom. Among them, from the viewpoint of further reducing the driving voltage of the OLED, it is more preferable to contain an alkali metal atom, a rare earth metal atom, or a copper group atom.

[0150] Further, in view of easy evaporation in a vacuum and easy handling, the donor material is preferably an inorganic salt or a ligand of a metal and an organic substance, rather than a simple substance metal. In addition, in view of easy handling in the atmosphere and easy adjustment of the concentration of the additive, a ligand of a metal and an organic substance is preferred. Examples of the inorganic salt include oxides, nitrides, fluorides, or carbonates, and the like. As the organic substance in the ligand of the organic substance and the metal, hydroxyquinoline, benzo hydroxyquinoline, pyridylphenol, flavonol, hydroxyimidazopyridine, hydroxybenzoxazole, or hydroxytriazole, and the like can be given. Of these, from the viewpoint of further reduction of the driving voltage of the OLED device, a ligand of an alkali metal and an organic substance is preferred. In addition, from the viewpoint of ease of synthesis and thermal stability, a ligand of lithium and an organic substance is more preferred, and particularly, hydroxyquinolinolato lithium (Liq) which can be obtained at a relatively low price is especially preferred.

[0151] The ionization potential of the electron transport layer is not particularly limited, but is preferably 5.6 eV or more and 8.0 eV or less, and more preferably 5.6 eV or more and 7.0 eV or less.

[0152] The method for forming each layer constituting the OLED device is not particularly limited, and resistance heating evaporation, electron beam evaporation, sputtering, molecular lamination, coating, printing, or the like can be given. From the viewpoint of the characteristics of the device, resistance evaporation or electron beam evaporation is preferred.

[0153] Electron injection layer

[0154] In the present application, an electron injection layer can be provided between the cathode and the electron transport layer. In general, the electron injection layer is introduced to assist the injection of electrons from the cathode to the electron transport layer, and when this layer is used, a compound having a heteroaromatic ring structure containing an electron-accepting nitrogen can be used, and a layer containing the above-mentioned donor material can also be used.

[0155] In addition, the electron injection layer can also use an inorganic material such as an insulator or a semiconductor, and a well-known material can be used. By using these materials, short circuiting of the OLED device can be suppressed, and the electron injection property can be improved.

[0156] The insulator is preferably at least one metal compound selected from the group consisting of an alkali metal chalcogenide, an alkaline earth metal chalcogenide, an alkali metal halide, or an alkaline earth metal halide.

[0157] Further, a ligand of an organic substance and a metal is also suitable for use. When the electron injection layer uses a ligand of an organic substance and a metal, the film thickness can be easily adjusted. Preferred examples of the organic substance in the organometallic ligand include hydroxyquinoline, benzo hydroxyquinoline, pyridylphenol, flavonol, hydroxyimidazopyridine, hydroxybenzoxazole, or hydroxytriazole, and the like.

[0158] The layer containing the compound represented by General Formula 1 has high electron injection property, and is excellent as an electron injection layer, and thus the compound of General Formula 1 is preferably used as an electron injection layer. In addition, the electron injection layer preferably contains an alkali metal atom, a rare earth metal atom, or a copper group atom in addition to the compound represented by General Formula 1. This combination can further reduce the driving voltage and improve the lifetime.

[0159] Charge generation layer

[0160] The charge generation layer in the present application is generally composed of two layers, and specifically, a PN junction type charge generation layer composed of an N-type charge generation layer and a P-type charge generation layer is preferably used. When a voltage is applied to an OLED device, the PN junction type charge generation layer generates charges, and the charges are separated into holes and electrons, the generated holes pass through a hole transport layer, and the electrons pass through an electron transport layer, and are injected into a light emitting layer. As a specific use method of the charge generation layer, the following example can be given: in an OLED device in which a plurality of light emitting layers are stacked, the layer is disposed between the plurality of light emitting layers and has a charge generation function. The N-type charge generation layer supplies electrons to a first light emitting layer on the anode side, and the P-type charge generation layer supplies holes to a second light emitting layer on the cathode side. Thus, the OLED device in which a plurality of light emitting layers are stacked can further improve the light emitting efficiency, reduce the driving voltage, and improve the lifetime.

[0161] The N-type charge generation layer is composed of an N-type dopant material and a host material, and a conventional material can be used. For example, an alkali metal, an alkaline earth metal, or a rare earth metal can be used as the N-type dopant material. As the host material, a compound having a nitrogen-containing aromatic heterocycle such as a phenanthroline derivative or an oligopyridine derivative can be used. In particular, a compound represented by General Formula 1 or a phenanthroline dimer is preferred because it exhibits excellent characteristics as a host material of an N-type charge generation layer.

[0162] As one embodiment of the charge generation layer, a phenanthroline derivative is preferably contained in addition to the compound represented by General Formula 1. Examples of the phenanthroline derivative can include the following compounds:

[0163] As one embodiment of the charge generation layer, an alkali metal atom, a copper group atom, or a rare earth metal atom is preferably contained in addition to the compound represented by General Formula 1. The alkali metal atom is preferably a Li atom. The copper group atom is preferably an Ag atom. The rare earth metal atom is preferably a Yb atom.

[0164] As one embodiment of the charge generation layer, a structure in which a phenanthroline derivative is further contained in addition to the compound represented by General Formula 1 and an alkali metal atom, a copper group atom, or a rare earth metal atom is preferably contained.

[0165] The P-type charge generation layer is composed of a P-type dopant and a host, and a conventional material can be used. For example, the P-type dopant, tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), a tetracyanoquinodimethane derivative, an axiophene derivative, iodine, FeCl3, FeF3, or SbCl5, or the like can be used. The P-type dopant is preferably an axiophene derivative. The host material is preferably an arylamine derivative. The P-type dopant can use a compound as follows.

[0166] The thickness of the organic layer is not limited depending on the resistance value of the light emitting substance, but is preferably 1 to 1000 nm. The thickness of each of the light emitting layer, the electron transporting layer, and the hole transporting layer is preferably 1 nm or more and 200 nm or less, and more preferably 5 nm or more and 100 nm or less.

[0167] The OLED device according to the present application can emit light using electric energy. The electric energy is mainly direct current, but pulse current or alternating current can also be used. The current and voltage are not particularly limited, but should be selected in consideration of the power consumption and the life of the device so as to emit the maximum brightness with the lowest possible energy.

[0168] The OLED device according to the present application is suitable for use as a display device such as a display in a matrix and / or a segmented form. In addition, it is also suitable for use as a thin and light display having a light sensor.

[0169] The OLED device according to the present application is suitable for use as a display device such as a display in various electronic devices. For example, electronic devices such as mobile phones, smartphones, tablet terminals, notebook computers, and wearable terminals are striving to save power and improve the life, and the OLED device according to the present application can provide a longer life than conventional OLED devices.

[0170] The OLED device according to the present application is suitable for use as a backlight for various devices. The backlight is mainly used to improve the visibility of a display device such as a non-self-emitting display, and is applied to liquid crystal displays, watches, audio devices, automobile panels, display panels, and signs, and the like. The organic EL element of the present application is preferably used for a backlight for a liquid crystal display, particularly a personal computer considering thinness, and can provide a thinner and lighter backlight than existing backlights.

[0171] The OLED device according to the present application is suitable for use as various lighting devices. The organic OLED device according to the embodiment of the present application can simultaneously improve the light emitting efficiency and provide high color purity, and can also be made thinner and lighter, thereby realizing a lighting device with a high design taste having a lower power consumption, a brighter light emitting color, and the like.

[0172]

EXAMPLE

[0173] The present application will be described below by way of examples, but the present application is not limited to these examples.

[0174] The chemical reagents used in the following examples and comparative examples were purchased from the companies of Sinopharm, Wako Pure Chemical Industries, Tokyo Chemical Industry, etc.

[0175] Synthesis Example 1: Synthesis of Compound 1

[0176] A mixture solution of 40.0 g of the starting material A, 50.4 g of 1-bromo-2-iodobenzene, 24.0 g of sodium carbonate, 1.6 g of dichlorobis(triphenylphosphine palladium) dichloride, 1620 ml of tetrahydrofuran and 280 ml of water was stirred under reflux with heating under a nitrogen atmosphere for 8 hours. After cooling to room temperature, water was added, the organic layer was extracted with ethyl acetate, evaporated, and dried in vacuum to obtain 31.8 g of the intermediate A.

[0177] At 0°C under a stream of nitrogen, 27 ml of n-butyllithium (1.6 M hexane solution) was added dropwise to a mixture solution of 16.7 g of the intermediate A and 27 ml of tetrahydrofuran. After stirring at 0°C for 30 minutes, a mixture solution of 10 g of the starting material B and 60 ml of THF was added dropwise while maintaining the temperature at 0°C. After raising the temperature to room temperature, 60 ml of a saturated aqueous ammonium chloride solution was added to the reaction solution. The organic layer was extracted with ethyl acetate and the solvent was removed. To the obtained solid were added 60 ml of dichloromethane and 6.7 g of manganese dioxide, and the mixture solution was stirred at room temperature for 1 hour. The reaction solution was filtered, the filtrate was evaporated and concentrated, the remaining solid was washed with methanol, and dried in vacuum, and recrystallized from toluene to obtain 9.1 g of Compound 1.

[0178] The obtained Compound 1 was purified by sublimation at a pressure of about 320°C, 1 x 10 -3 Pa using an oil diffusion pump. The HPLC purity (area % at a measuring wavelength of 254 nm) of the Compound 1 after sublimation purification was 99.9%.

[0179] The structure of Compound 1 was identified by mass spectrometry (MS) analysis after sublimation purification. The analysis results are shown below.

[0180] MS (m / z): 533 [M+H]+

[0181] Synthesis Example 2: Synthesis of Compound 2

[0182] A mixture solution of 20.0 g of the starting material C, 10.2 g of 2-chlorobenzeneboronic acid, 8.8 g of sodium carbonate, 420 mg of dichlorobis(triphenylphosphine palladium) dichloride, 600 ml of tetrahydrofuran and 100 ml of water was stirred under reflux with heating under a nitrogen atmosphere for 8 hours. After cooling to room temperature, water was added, filtered, washed with methanol, and dried in vacuum to obtain 17.7 g of the intermediate B.

[0183] Next, a mixed solution of 14.0 g of the intermediate C, 8.6 g of the raw material A, 10.0 g of tri-potassium phosphate, 220 mg of dichlorobis(triphenylphosphine palladium) dichloride, 320 ml of 1,4-dioxane, and 50 ml of water was heated and stirred under a nitrogen atmosphere for 8 hours. After cooling to room temperature, water was added and filtration was performed. The catalyst was removed using activated carbon, and the solvent was evaporated to obtain a solid, which was recrystallized using toluene and then vacuum-dried to obtain 7.1 g of the compound 3.

[0184] The obtained compound 2 was purified by sublimation using an oil diffusion pump at a pressure of about 330°C, 1 x 10 -3 Pa. The HPLC purity of the compound 2 after sublimation purification (area% at a measurement wavelength of 254 nm) was 99.9%.

[0185] After sublimation purification, the structure of the compound 2 was identified by mass spectrometry (MS) analysis. The analysis results are shown below.

[0186] MS (m / z): 533 [M+H]+

[0187] Synthesis Example 3: Synthesis of Compound 3

[0188] A mixed solution of 20.0 g of the raw material D, 8.3 g of 2-chlorophenylboronic acid, 7.7 g of sodium carbonate, 340 mg of dichlorobis(triphenylphosphine palladium) dichloride, 490 ml of tetrahydrofuran, and 80 ml of water was heated and stirred under a nitrogen atmosphere at reflux for 8 hours. After cooling to room temperature, water was added, filtration was performed, methanol was used for washing, and vacuum-drying was performed to obtain 15.5 g of the intermediate C.

[0189] Next, a mixed solution of 14.0 g of the intermediate C, 8.6 g of the raw material A, 10.0 g of tri-potassium phosphate, 220 mg of dichlorobis(triphenylphosphine palladium) dichloride, 320 ml of 1,4-dioxane, and 50 ml of water was heated and stirred under a nitrogen atmosphere for 8 hours. After cooling to room temperature, water was added and filtration was performed. The catalyst was removed using activated carbon, and the solvent was evaporated to obtain a solid, which was recrystallized using toluene and then vacuum-dried to obtain 7.1 g of the compound 3.

[0190] The obtained compound 3 was purified by sublimation using an oil diffusion pump at a pressure of about 330°C, 1 x 10 -3 Pa. The HPLC purity of the compound 3 after sublimation purification (area% at a measurement wavelength of 254 nm) was 99.9%.

[0191] After sublimation purification, the structure of the compound 3 was identified by mass spectrometry (MS) analysis. The analysis results are shown below.

[0192] Mass (m / z): 609 [M+H]+

[0193] Synthesis Example 4: Synthesis of Compound 4

[0194] A mixture solution of 17.5 g of the starting material E, 15.0 g of the intermediate A, 11.3 g of potassium phosphate tribasic, 270 mg of dichlorobis(triphenylphosphine palladium) dichloride, 380 ml of 1,4-dioxane and 60 ml of water was stirred under heating for 8 hours under a nitrogen atmosphere. After cooling to room temperature, water was added and filtered. The catalyst was removed using activated carbon, and after evaporating the solvent to obtain a solid, recrystallization was performed using toluene, and then vacuum dried to obtain 9.1 g of Compound 4.

[0195] The obtained Compound 4 was purified by sublimation using an oil diffusion pump at a pressure of about 340°C, 1 x 10 -3 Pa. The HPLC purity (area % at a measuring wavelength of 254 nm) of the Compound 4 after sublimation purification was 99.9%.

[0196] After sublimation purification, the structure of Compound 4 was identified by mass spectrometry (MS) analysis. The analysis results are shown below.

[0197] Mass (m / z): 609 [M+H]+

[0198] Synthesis Example 5: Synthesis of Compound 5

[0199] While being protected by nitrogen, 70 ml of n-butyllithium (1.6 M hexane solution) was added dropwise to a mixture solution of 32 g of 2-bromo-4'-chloro-1,1'-biphenyl and 70 ml of tetrahydrofuran at 0°C. After stirring for 30 minutes at 0°C, the mixture was added dropwise to a mixture solution of 18 g of 1,10-phenanthroline and 140 ml of THF. After heating to room temperature, 140 ml of a saturated aqueous ammonium chloride solution was added to the reaction solution. The organic layer was extracted with ethyl acetate and evaporated. To the obtained solid, 140 ml of dichloromethane and 17.2 g of manganese dioxide were added, and stirred at room temperature for 1 hour. The reaction solution was filtered, and the filtrate was evaporated and concentrated, and the remaining solid was washed with hexane and vacuum dried to obtain 13.7 g of the intermediate D.

[0200] Next, a mixture solution of 13.0 g of the intermediate D, 9.2 g of the starting material A, 500 mg of dichlorobis(triphenylphosphine) palladium, 360 ml of 1,4-dioxane and 60 ml of water was stirred under heating and reflux for 5 hours under a nitrogen stream. After cooling to room temperature, water was added, filtered, washed with methanol, and vacuum dried. The catalyst in the obtained solid was removed using activated carbon, and the solvent was evaporated to obtain a solid, which was recrystallized using toluene, and then vacuum dried to obtain 9.4 g of Compound 5.

[0201] The obtained compound 5 was sublimed at about 320°C under 1 x 10 -3 The HPLC purity (area percentage measured at 254 nm) of compound 5 after sublimation was 99.9%.

[0202] After sublimation, the structure of compound 5 was identified by mass spectrometry (MS) analysis. The results of the analysis are shown below.

[0203] MS (m / z): 533 [M+H]+

[0204] Synthesis Example 6: Synthesis of compound 6

[0205] Under a stream of nitrogen, 22 ml of n-butyllithium (1.6 M hexane solution) was added dropwise to a mixed solution of 14.0 g of intermediate A and 22 ml of tetrahydrofuran at 0°C. After stirring at 0°C for 30 minutes, the mixture was added dropwise to a mixed solution of 10.0 g of starting material G and 44 ml of tetrahydrofuran at 0°C. After warming to room temperature, 80 ml of a saturated aqueous ammonium chloride solution was added to the reaction solution. The organic layer was extracted with ethyl acetate and evaporated. To the obtained solid, 80 ml of dichloromethane and 5.6 g of manganese dioxide were added, and stirred at room temperature for 1 hour. The reaction solution was filtered, and the filtrate was evaporated and concentrated, and the remaining solid was recrystallized from toluene and dried under vacuum to obtain 11.5 g of compound 6.

[0206] The obtained compound 6 was sublimed at about 320°C under 1 x 10 -3 The HPLC purity (area percentage measured at 254 nm) of compound 6 after sublimation was 99.9%.

[0207] After sublimation, the structure of compound 6 was identified by mass spectrometry (MS) analysis. The results of the analysis are shown below.

[0208] MS (m / z): 583 [M+H]+

[0209] Synthesis Example 7: Synthesis of compound 7

[0210] A mixed solution of 10.0 g of starting material H, 8.8 g of starting material F, 360 mg of bis(triphenylphosphine)palladium dichloride, 260 ml of 1,4-dioxane, and 45 ml of water was stirred under a stream of nitrogen at reflux for 5 hours. After cooling to room temperature, water was added, filtered, washed with methanol, and dried under vacuum. The catalyst in the obtained solid was removed with activated carbon, and the solvent was evaporated. The obtained solid was recrystallized from toluene and dried under vacuum to obtain 7.5 g of compound 7.

[0211] The obtained compound 7 was sublimed at about 320°C under 1 x 10-3 The obtained compound 7 was sublimed under a pressure of about 1 x 10

[0212] After sublimation purification, the structure of compound 7 was identified by mass spectrometry (MS) analysis. The analysis results are as follows:

[0213] MS (m / z): 583 [M+H]+

[0214] Synthesis Example 8: Synthesis of Compound 8

[0215] A mixture solution of 9.0 g of the starting material I, 6.6 g of the starting material F, 290 mg of bis(triphenylphosphine)palladium dichloride, 200 ml of 1,4-dioxane and 30 ml of water was stirred under reflux with heating under a stream of nitrogen for 5 hours. After cooling to room temperature, water was added, filtered, washed with methanol and dried in vacuum. The catalyst in the obtained solid was removed with activated carbon and the solvent was evaporated. The obtained solid was recrystallized with toluene and dried in vacuum to obtain 7.0 g of compound 8.

[0216] The obtained compound 8 was sublimed under a pressure of about 1 x 10 -3 Pa at about 320°C using an oil diffusion pump. The HPLC purity (area %) of compound 8 after sublimation purification was 99.9%.

[0217] After sublimation purification, the structure of compound 8 was identified by mass spectrometry (MS) analysis. The analysis results are as follows:

[0218] MS (m / z): 659 [M+H]+

[0219] Synthesis Example 9: Synthesis of Compound 9

[0220] A mixture solution of 17.0 g of intermediate B, 12.5 g of the starting material G, 13.8 g of potassium phosphate tribasic, 320 mg of dichlorobis(triphenylphosphine palladium) dichloride, 460 ml of 1,4-dioxane and 80 ml of water was stirred under reflux with heating under a nitrogen atmosphere for 8 hours. After cooling to room temperature, water was added and filtered. The catalyst was removed using activated carbon and the solvent was evaporated by rotary evaporation. The obtained solid was recrystallized with toluene and dried in vacuum to obtain 11.0 g of compound 9.

[0221] The obtained compound 9 was sublimed under a pressure of about 1 x 10 -3 Pa at about 330°C using an oil diffusion pump. The HPLC purity (area %) of compound 9 after sublimation purification was 99.9%.

[0222] The structure of the compound 9 was identified by mass spectrometry (MS) analysis after sublimation purification. The analysis results are shown below.

[0223] MS (m / z): 533 [M+H]+

[0224] Synthesis Example 10: Synthesis of Compound 10

[0225] A mixed solution of the starting material H 9.3 g, the intermediate F 8.6 g, tri- potassium phosphate 13.8 g, dichlorobis(triphenylphosphine palladium) dichloride 320 mg, 1,4-dioxane 460 ml, and water 80 ml was heated and stirred under reflux in a nitrogen atmosphere for 8 hours. After cooling to room temperature, water was added and filtered. The catalyst was removed using activated carbon, and the solvent was removed by rotary evaporation. The obtained solid was recrystallized from toluene, and then vacuum dried to obtain 8.6 g of the compound 10.

[0226] The compound 10 obtained by sublimation purification using an oil diffusion pump at a pressure of about 340°C, 1 x 10 -3 Pa. The HPLC purity of the compound 10 after sublimation purification (area% at a measurement wavelength of 254 nm) was 99.9%.

[0227] The structure of the compound 10 was identified by mass spectrometry (MS) analysis after sublimation purification. The analysis results are shown below.

[0228] MS (m / z): 609 [M+H]+

[0229] Synthesis Example 11: Synthesis of Compound 11

[0230] A mixed solution of the starting material I 8.6 g, the starting material A 5.2 g, tri- potassium phosphate 13.8 g, dichlorobis(triphenylphosphine palladium) dichloride 320 mg, 1,4-dioxane 460 ml, and water 80 ml was heated and stirred under reflux in a nitrogen atmosphere for 8 hours. After cooling to room temperature, water was added and filtered. The catalyst was removed using activated carbon, and the solvent was removed by rotary evaporation. The obtained solid was recrystallized from toluene, and then vacuum dried to obtain 6.5 g of the compound 11.

[0231] The compound 11 obtained by sublimation purification using an oil diffusion pump at a pressure of about 290°C, 1 x 10 -3 Pa. The HPLC purity of the compound 11 after sublimation purification (area% at a measurement wavelength of 254 nm) was 99.9%.

[0232] The structure of the compound 11 was identified by mass spectrometry (MS) analysis after sublimation purification. The analysis results are shown below.

[0233] MS (m / z): 457 [M+H]+

[0234] Synthesis Example 12: Synthesis of Compound 12

[0235] A mixed solution of starting material J 7.8 g, starting material A 5.2 g, tri- potassium phosphate 13.8 g, dichlorobis(triphenylphosphine palladium) dichloride 320 mg, 1,4-dioxane 460 ml, and water 80 ml was stirred under reflux with heating in a nitrogen atmosphere for 8 hours. After cooling to room temperature, water was added and filtered. The catalyst was removed using activated carbon, and the solvent was removed by rotary evaporation. The resulting solid was recrystallized from toluene, and then vacuum dried to obtain 7.8 g of compound 12.

[0236] The obtained compound 12 was purified by sublimation using an oil diffusion pump at a pressure of about 330°C, 1 x 10 -3 Pa. The HPLC purity of the sublimation-purified compound 12 (area% at a measurement wavelength of 254 nm) was 99.9%.

[0237] After sublimation purification, the structure of compound 12 was identified by mass spectrometry (MS) analysis. The analysis results are shown below.

[0238] MS (m / z): 533 [M+H]+

[0239] Synthesis Example 13: Synthesis of Compound 13

[0240] A mixed solution of starting material K 8.2 g, starting material A 5.2 g, tri- potassium phosphate 13.8 g, dichlorobis(triphenylphosphine palladium) dichloride 320 mg, 1,4-dioxane 460 ml, and water 80 ml was stirred under reflux with heating in a nitrogen atmosphere for 8 hours. After cooling to room temperature, water was added and filtered. The catalyst was removed using activated carbon, and the solvent was removed by rotary evaporation. The resulting solid was recrystallized from toluene, and then vacuum dried to obtain 5.2 g of compound 13.

[0241] The obtained compound 13 was purified by sublimation using an oil diffusion pump at a pressure of about 290°C, 1 x 10 -3 Pa. The HPLC purity of the sublimation-purified compound 13 (area% at a measurement wavelength of 254 nm) was 99.9%.

[0242] After sublimation purification, the structure of compound 13 was identified by mass spectrometry (MS) analysis. The analysis results are shown below.

[0243] MS (m / z): 463 [M+H]+

[0244] Synthesis Example 14: Synthesis of Compound 14

[0245] A mixture solution of raw material L 7.6 g, raw material A 5.2 g, tripotassium phosphate 13.8 g, dichlorobis(triphenylphosphine palladium) dichloride 320 mg, 1,4-dioxane 460 ml, water 80 ml was stirred under reflux with heating in a nitrogen atmosphere for 8 hours. After cooling to room temperature, water was added and filtration was performed. The catalyst was removed using activated carbon, and the solvent was removed by rotary evaporation, and the obtained solid was recrystallized from toluene, and then vacuum dried to obtain 8.1 g of compound 14.

[0246] The obtained compound 14 was purified by sublimation using an oil diffusion pump at a pressure of about 310°C, 1 x 10 -3 Pa. The HPLC purity of the compound 14 after sublimation purification (area% at a measurement wavelength of 254 nm) was 99.9%.

[0247] The structure of the compound 14 after sublimation purification was identified by mass spectrometry (MS) analysis. The analysis results are shown below.

[0248] MS (m / z): 547 [M+H]+

[0249] Synthesis Example 15: Synthesis of Compound 15

[0250] A mixture solution of raw material M 10.6 g, raw material A 5.2 g, tripotassium phosphate 13.8 g, dichlorobis(triphenylphosphine palladium) dichloride 320 mg, 1,4-dioxane 460 ml, water 80 ml was stirred under reflux with heating in a nitrogen atmosphere for 8 hours. After cooling to room temperature, water was added and filtration was performed. The catalyst was removed using activated carbon, and the solvent was removed by rotary evaporation, and the obtained solid was recrystallized from toluene, and then vacuum dried to obtain 9.6 g of compound 15.

[0251] The obtained compound 15 was purified by sublimation using an oil diffusion pump at a pressure of about 330°C, 1 x 10 -3 Pa. The HPLC purity of the compound 15 after sublimation purification (area% at a measurement wavelength of 254 nm) was 99.9%.

[0252] The structure of the compound 15 after sublimation purification was identified by mass spectrometry (MS) analysis. The analysis results are shown below.

[0253] MS (m / z): 609 [M+H]+

[0254] Synthesis Example 16: Synthesis of Compound 16

[0255] A mixture solution of 11.4 g of the raw material N, 5.2 g of the raw material A, 13.8 g of tri-potassium phosphate, 320 mg of dichlorobis(triphenylphosphine palladium) dichloride, 460 ml of 1,4-dioxane, and 80 ml of water was stirred under reflux for 8 hours in a nitrogen atmosphere. After cooling to room temperature, water was added and filtered. The catalyst was removed using activated carbon, and the solvent was removed by rotary evaporation. The obtained solid was recrystallized from toluene, and then vacuum dried to obtain 8.3 g of compound 16.

[0256] Compound 16 obtained was purified by sublimation at a pressure of about 340°C, 1 x 10 -3 Pa using an oil diffusion pump. The HPLC purity of compound 16 after sublimation purification (area % at a measurement wavelength of 254 nm) was 99.9%.

[0257] The structure of compound 16 was identified by mass spectrometry (MS) analysis after sublimation purification. The analysis results are shown below.

[0258] MS (m / z): 659 [M+H]+

[0259] Synthesis Example 17: Synthesis of Compound 17

[0260] A mixture solution of 8.4 g of the raw material O, 5.2 g of the raw material A, 13.8 g of tri-potassium phosphate, 320 mg of dichlorobis(triphenylphosphine palladium) dichloride, 460 ml of 1,4-dioxane, and 80 ml of water was stirred under reflux for 8 hours in a nitrogen atmosphere. After cooling to room temperature, water was added and filtered. The catalyst was removed using activated carbon, and the solvent was removed by rotary evaporation. The obtained solid was recrystallized from toluene, and then vacuum dried to obtain 5.2 g of compound 17.

[0261] Compound 17 obtained was purified by sublimation at a pressure of about 330°C, 1 x 10 -3 Pa using an oil diffusion pump. The HPLC purity of compound 17 after sublimation purification (area % at a measurement wavelength of 254 nm) was 99.9%.

[0262] The structure of compound 17 was identified by mass spectrometry (MS) analysis after sublimation purification. The analysis results are shown below.

[0263] MS (m / z): 609 [M+H]+

[0264] In addition to the above, compounds 18 to 22 were synthesized by selecting appropriate raw materials according to the above synthesis method.

[0265] In addition, compounds 1 to 22 are the compounds shown below.

[0266] Next, the evaluation method of each of the examples and comparative examples will be described.

[0267] (1) Driving voltage:

[0268] The OLED devices obtained in Examples 1 to 37 and Comparative Examples 1 to 12 were respectively driven at 10 mA / cm 2 with direct current, and the initial driving voltage was measured. In addition, the voltage at the time of driving at 10 mA / cm 2 with direct current for 100 hours in an environment at 70°C was measured, and the voltage increase amount with respect to the initial driving voltage was calculated.

[0269] In addition, the OLED devices obtained in Examples 38 to 111 and Comparative Examples 13 to 36 were respectively lit at a luminance of 1000 cd / m 2 , and the initial driving voltage was measured. In addition, the voltage at the time of driving at 10 mA / cm 2 with constant current for 100 hours at room temperature was measured, and the voltage increase amount with respect to the initial driving voltage was calculated.

[0270] The lower the initial driving voltage, the lower the voltage at the time of starting, and thus it can be said that the higher the luminous efficiency (luminance / power). In addition, the smaller the voltage increase amount, the longer the life.

[0271] (2) External quantum efficiency:

[0272] The OLED devices obtained in Examples 38 to 111 and Comparative Examples 13 to 36 were lit at 10 mA / cm 2 , and the external quantum efficiency was measured using a spectrophotometer (manufactured by Konica Minolta, Inc.), and the luminous efficiency was evaluated. The higher the external quantum efficiency, the better the luminous efficiency.

[0273] (3) Life

[0274] The OLED devices obtained in Examples 38 to 111 and Comparative Examples 13 to 36 were continuously driven at 10 mA / cm 2 with constant current, and the time required for the luminance to decrease by 20% from the initial luminance was the life.

[0275] Example 1

[0276] A 125-nm-thick ITO transparent conductive film was deposited on a glass substrate (manufactured by Geomo Technology Co., Ltd., 11 Ω / D, sputtered product) as an anode, and the glass substrate was cut into 38 mm x 46 mm and etched. The resulting substrate was subjected to ultrasonic cleaning using "Semi-Clean" (registered trademark) 56 (trade name, manufactured by FUJIFILM Wako Chemicals U.S.A. Corp.) for 15 minutes, and then cleaned with ultrapure water. Before the single-charge element was produced, the substrate was subjected to UV-ozone treatment for 1 hour, and was introduced into a vacuum deposition device, and was evacuated until the degree of vacuum in the device reached 5 x 10 -4 -6 Pa. Using a resistance heating method, the compound 1 : Yb = 9: 1 was deposited at a rate ratio until a 100-nm-thick layer of 9: 1 by weight was formed, in which Yb was used as a doping metal. Thereafter, aluminum was vapor-deposited to form a 60-nm-thick cathode, and a 5 mm x 5 mm square single-charge device was produced. The film thickness was the value displayed on a crystal vibration type film thickness monitor, and the same applied to other examples and comparative examples.

[0277] When the single-charge device was evaluated by the above method, the initial driving voltage was 0.097 V, and the voltage increase amount when driven for 100 hours at 70°C was 0.035 V.

[0278] Examples 2 to 37, Comparative Examples 1 to 12

[0279] The method of producing a single-charge device was the same as that of Example 1, except that the compound, the metal element, and the rate ratio of the compound to the metal element used were changed as shown in Table 1. Table 1 shows the results of each example and comparative example.

[0280] [Table 1]

[0281] Example 38

[0282] A 165-nm-thick ITO transparent conductive film was deposited on a glass substrate (manufactured by Geomo Technology Co., Ltd., 11 Ω / D, sputtered product) as an anode, and the glass substrate was cut into 38 mm x 46 mm and etched. The resulting substrate was subjected to ultrasonic cleaning using "Semi-Clean" (registered trademark) 56 (trade name, manufactured by FUJIFILM Wako Chemicals U.S.A. Corp.) for 15 minutes, and then cleaned with ultrapure water. Before the single-charge element was produced, the substrate was subjected to UV-ozone treatment for 1 hour, and was introduced into a vacuum deposition device, and was evacuated until the degree of vacuum in the device reached 5 x 10 -4Pa or less. The OLED device was produced in the same manner as in Example 38, except that the thickness of the compound 1 and the metal element Yb was changed to 10 nm. Table 1 shows the results of each example and comparative example.

[0283] The OLED device was evaluated by the above method, and the initial driving voltage was 4.61 V, the external quantum efficiency (luminous efficiency) was 5.18%, the lifetime was 1040 hours, and the voltage increase amount was 0.015 V when driven for 100 hours at room temperature. In addition, P-D1, HT-1, H-1, D-1, ET-1, and 2E-1 were the compounds shown below.

[0284] Examples 39 to 74, Comparative Examples 13 to 24

[0285] The compound, the metal element, and the evaporation rate ratio of the compound to the metal element used were changed as shown in Table 2, and the OLED device was produced in the same manner as in Example 38. Table 2 shows the results of each example and comparative example.

[0286] [Table 2]

[0287] Example 75

[0288] A glass substrate (manufactured by Diamantec, 11 Ω / D, sputtering product) on which a 165 nm-thick ITO transparent conductive film was deposited as an anode was cut into 38 mm x 46 mm and etched. The resulting substrate was subjected to ultrasonic cleaning using "Semi-Clean" (registered trademark) 56 (trade name, manufactured by FUJIFILM Wako Chemicals U.S.A.) for 15 minutes, and then cleaned with ultrapure water. Before producing a single charge element, the substrate was subjected to UV-ozone treatment for 1 hour, and was placed in a vacuum evaporation device, and was subjected to evacuation until the degree of vacuum in the device reached 5 x 10 -4 Pa or less. The OLED device was produced in the same manner as in Example 38, except that the thickness of the compound 1 and the metal element Yb was changed to 10 nm. Table 1 shows the results of each example and comparative example.

[0289] Specifically, 50 nm thick of HT-1 was evaporated as a hole transport layer. Next, as a light emitting layer, a host material H-1 and a dopant material D-1 were evaporated at a doping concentration of 5% by weight so that a mixed layer thereof reached a thickness of 20 nm. Next, as an electron transport layer, ET-1 and 2E-1 were evaporated so that the evaporation rate ratio of ET-1 and 2E-1 = 1:1, to a thickness of 35 nm.

[0290] On the first light emitting unit, as an N-type charge generation layer, compound 1 and a metal element Yb as a dopant material were evaporated at an evaporation rate ratio of compound 1 : Yb = 9:1 to a thickness of 10 nm, and next, as a P-type charge generation layer, P-D1 was evaporated to a thickness of 10 nm.

[0291] After the charge generation layer, a second light emitting unit was formed in the same manner as the first light emitting unit. Thereafter, as an electron injection layer, compound 1 and a metal element Yb as a dopant material were evaporated at an evaporation rate ratio of compound 1 : Yb = 9:1 to a thickness of 10 nm. Thereafter, aluminum was evaporated to a thickness of 60 nm to form a cathode, and an OLED device of 5 mm x 5 mm square was manufactured.

[0292] The organic EL element was evaluated by the above-described method, and as a result, the initial driving voltage was 9.14 V, the external quantum efficiency (luminous efficiency) was 10.40%, the durability life was 2130 hours, and the voltage increase amount when driven for 100 hours at room temperature was 0.010 V.

[0293] Examples 76-111, Comparative Examples 25-36

[0294] The compound used and the evaporation rate ratio of the compound and the metal element were changed as shown in Table 3, and otherwise, an OLED device was manufactured in the same manner as in Example 75. Table 3 shows the results of each example and comparative example.

[0295]

Table 3

[0296] Examples 1 to 37 show the results of single charge devices formed using compounds represented by general formula 1 and alkali metal element Li or rare earth metal element Yb. On the other hand, Comparative Examples 1 to 6 show the results of single charge devices formed using compounds 18 and 19 (not within the scope of general formula 1) and alkali metal element Li or rare earth metal Yb. Each of the examples has a lower initial driving voltage, a longer lifetime and a smaller increase in driving voltage compared to each of the comparative examples. This is because the compounds 1 to 17 represented by general formula 1 have higher stability of the film compared to compounds 18 and 19. On the other hand, Comparative Examples 7 to 12 show the results of single charge devices formed using compounds 20, 21 and 22 (not within the scope of general formula 1) and alkali metal element Li or rare earth metal Yb. Each of the examples has a lower initial driving voltage, a longer lifetime and a smaller increase in driving voltage compared to each of the comparative examples. This is because the compounds 1 to 17 represented by general formula 1 can form a stable ligand with the alkali metal element using two nitrogen-containing aromatic groups connected by a fused ring, which is better than one nitrogen-containing aromatic group or multiple nitrogen-containing aromatic groups connected by a single bond or the like, thereby improving the device performance.

[0297] In addition, in Examples 38 to 74, the organic layer used in Examples 1 to 37 was made into a light emitting device. On the other hand, Comparative Examples 13 to 24 made the organic layer used in Comparative Examples 1 to 12 into a light emitting device. Each of the examples has a lower initial driving voltage, a higher external quantum efficiency, a longer lifetime and a smaller increase in driving voltage compared to each of the comparative examples. This result shows that the compounds provided by general formula 1 can form a light emitting device with higher efficiency and stability, and the results have the same trend as the single charge device. In the comparison between Example 46 and Example 39, it can be seen that the connection site of fluoranthene in Example 39 can make the overall crystallinity of the molecule lower, thereby improving the film forming property and slightly extending the lifetime. In the comparison between Example 47 and Example 39, it can be seen that when the number of benzene rings connecting fluoranthene and phenanthroline is too large, the crystallinity will be improved, thereby reducing the lifetime. By comparing Example 48 with Example 54, it can be seen that when R 1 -R 7 When these sites that greatly affect the metal coordination ability are substituted, the overall metal coordination ability of the substituted phenanthroline is reduced, thereby causing the overall device performance to be reduced. By comparing Examples 50, 51 and Example 48, it can be found that L 1 -L 3 When containing heteroatoms, the coordination ability with the metal can be enhanced, thereby reducing the voltage of the device, but on the other hand, these heteroatoms can increase the refractive index of the molecule, thereby reducing the light extraction efficiency. Among them, the non-benzene structure used in Example 50 compared to the benzene structure used in Example 51, the benzene can dilute the refractive index increasing effect of the heterocycle, thereby slightly improving the efficiency.

[0298] Further, in Examples 75 to 111, the stacked light-emitting devices were fabricated using the compounds represented by General Formula 1 in the charge generation layer and the device performances were tested. In Comparative Examples 25 to 36, the light-emitting devices fabricated in Comparative Examples 13 to 24 were fabricated into stacked devices and the device performances were tested. Compared with each of the comparative examples, each of the examples had a lower initial driving voltage, a higher external quantum efficiency, a longer lifetime, and a smaller increase in driving voltage. From this result, it was found that, as in the results of Examples 38 to 74 and Comparative Examples 13 to 24, the compounds represented by General Formula 1 can form stacked light-emitting devices with higher efficiency and stability.

Claims

1. A compound, characterized in that... : having the structure of Formula 1 below, In General Formula 1, R 1 ~R 18 each independently is selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group; L 1 ~L 3 each independently is selected from a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group; at least one of the L 1 ~L 3 is a group represented by General Formula 2 or General Formula 3: In General Formula 2 and General Formula 3, X 1 is selected from an oxygen atom, a sulfur atom, or N-R 25 ; R 19 ~R 25 are each independently selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group; R 19 ~R 22 may be linked to each other to form a ring structure; R 23 and R 24 may be linked to each other to form a ring structure; * indicates a bonding site.

2. The compound according to claim 1, wherein: The compounds have the following general structure 4, In General Formula 4, R 2 ~R 17 and L 1 ~L 3 have the same meanings as in General Formula 1.

3. The compound according to claim 1, wherein: R 2 ~R 7 is a hydrogen atom.

4. The compound according to claim 1, wherein: The group of the general formula 2 or general formula 3 is a group represented by any one of the following general formulae 5 to 13, In General Formula 8, X 2 is the same as X 1 in General Formula 3; in General Formula 9 to 11, X 3 is an oxygen atom, a sulfur atom, or N-R 26 ; R 26 is selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted cycloalkyl group; and * indicates a bonding site.

5. The compound according to claim 4, wherein: L 1 ~L 3 at least one of R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, R23, R24, R25, R26, R27, R28, R29, R30, R31, R32, R33, 6. The compound according to claim 1, wherein: L 3 is a single bond.

7. A light-emitting device which emits light using electric energy, at least an electron transport layer and a light-emitting layer existing between an anode and a cathode, characterized by: the electron-transporting layer contains the compound according to any one of claims 1 to 6.

8. The light-emitting device according to claim 7, wherein: the electron-transporting layer further contains alkali metal atoms, rare earth metal atoms, or copper group atoms.

9. A light emitting device which emits light using electric energy, at least a charge generation layer and a light emitting layer existing between an anode and a cathode, characterized by: the charge-generating layer contains the compound according to any one of claims 1 to 6.

10. The light-emitting device according to claim 9, wherein: the charge-generating layer further contains a phenanthroline derivative.

11. The light-emitting device according to claim 9, wherein: the charge-generating layer further contains alkali metal atoms, rare earth metal atoms, or copper group atoms.

12. The light-emitting device according to claim 11, wherein: the alkali metal atom is a Li atom.

13. The light-emitting device according to claim 11, wherein: the rare earth metal atom is a Yb atom.

14. A light-emitting device which emits light using electric energy, at least an electron injection layer and a light-emitting layer existing between an anode and a cathode, characterized by: the electron-injecting layer contains the compound according to any one of claims 1 to 6.

15. The light-emitting device according to claim 14, wherein: the electron-injecting layer further contains alkali metal atoms, rare earth metal atoms, or copper group atoms.

16. A display device, wherein a light-emitting device containing the compound according to any one of claims 1 to 6 is used.

17. An electronic appliance, wherein a light-emitting device containing the compound according to any one of claims 1 to 6 is used.

18. An illumination device, wherein a light-emitting device containing the compound according to any one of claims 1 to 6 is used.

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