Organic electric field light-emitting element, its manufacturing method and hybrid composition

Abstract

An organic electric field light-emitting element (OLED) with improved luminous efficiency and sufficiently ensured stability during driving, thus providing practical usefulness, is disclosed, along with a method for manufacturing the same and a hybrid composition. The OLED comprises a light-emitting layer containing two distinct host materials and a dopant material. One host material is a compound represented by general formula (1), and the other host material is a compound represented by general formula (2). Ring A is a heterocycle represented by formula (1a), X is N or C-Ar', and Y is O, S, or N-Ar. 3 or C-Ar 4 Ar 5 Z 1 ~Z 4 Any one of them is a carbon atom bonded to a six-membered ring containing X, and the others and Z 5 ~Z 8 Indicates C-Ar' or N; Ar, Ar', and Ar 1 ~Ar 5 Ar is a heterocycle represented by formula (2a), consisting of hydrogen, alkyl groups having 1 to 20 carbon atoms, and ring B having the carbon number represented by hydrogen. 6 and Ar 7 It consists of hydrogen, alkyl groups having 1 to 20 carbon atoms, etc.

Description

Technical Field

[0001] This invention relates to an organic electric field light-emitting element (hereinafter referred to as an organic EL element), and more specifically to an organic EL element comprising a specific hybrid host material, a method for manufacturing the same, and a hybrid composition thereof. Background Technology

[0002] By applying a voltage to an organic EL (electroluminescence) device, holes are injected into the emissive layer from the anode, and electrons are injected into the emissive layer from the cathode. Furthermore, in the emissive layer, the injected holes and electrons recombine to generate excitons. At this point, according to the statistical law of electron spin, singlet and triplet excitons are generated in a 1:3 ratio. Regarding fluorescent organic EL devices using light emission generated by singlet excitons, the internal quantum efficiency is considered to be limited to 25%. On the other hand, phosphorescent organic EL devices using light emission generated by triplet excitons have achieved an internal quantum efficiency of 100% by efficiently performing intersystem crossings from singlet excitons.

[0003] Furthermore, high-efficiency organic EL devices utilizing delayed fluorescence are currently being developed. For example, Patent Document 1 discloses an organic EL device that utilizes the triplet-triplet fusion (TTF) mechanism, one of the mechanisms of delayed fluorescence. The TTF mechanism utilizes the phenomenon of generating singlet excitons through the collision of two triplet excitons, theoretically increasing the internal quantum efficiency to 40%. However, compared to phosphorescent organic EL devices, its efficiency is low, thus requiring further improvements in efficiency and low-voltage characteristics.

[0004] Furthermore, Patent Document 2 discloses an organic EL device that utilizes the Thermally Activated Delayed Fluorescence (TADF) mechanism. The TADF mechanism leverages the following phenomenon: in materials with a small energy difference between singlet and triplet levels, an inverse intersystem crossing from a triplet exciton to a singlet exciton occurs; theoretically, this increases the internal quantum efficiency to 100%.

[0005] However, there is room for improvement in efficiency and lifespan in either mechanism, and improvements are also required for reducing the drive voltage.

[0006] On the other hand, Patent Documents 3 and 4 disclose the use of indobenzocarbazole compounds with condensed heterocycles substituted as host materials. Furthermore, Patent Documents 5 and 6 disclose the use of indobenzocarbazole compounds as mixed host materials. Additionally, Patent Document 7 discloses an organic EL element using a mixed host material of a compound with condensed heterocycles substituted on a nitrogen-containing 6-membered ring and a carbazole compound. Furthermore, Patent Document 8 discloses an organic EL element using a mixed host material of an indobenzocarbazole compound with condensed heterocycles substituted on a nitrogen-containing 6-membered ring and a specific indobenzocarbazole compound substituted with an aryl group. Furthermore, Patent Documents 9 and 10 disclose organic EL elements using mixed host materials of indobenzocarbazole compounds.

[0007] However, none of these organic EL devices can be considered to have sufficient characteristics, and further improvements, especially in efficiency and voltage, are desired.

[0008] [Existing Technical Documents]

[0009] [Patent Literature]

[0010] Patent Document 1: WO2010 / 134350

[0011] Patent Document 2: WO2011 / 070963

[0012] Patent Document 3: WO2013 / 137001

[0013] Patent Document 4: WO2013 / 122402

[0014] Patent Document 5: WO2016 / 023608

[0015] Patent Document 6: WO2018 / 198844

[0016] Patent Document 7: Japanese Patent Application Publication No. 2014-157947

[0017] Patent Document 8: WO2018236092

[0018] Patent Document 9: WO2016042997

[0019] Patent Document 10: WO2010098246 Summary of the Invention

[0020] [The problem the invention aims to solve]

[0021] In order to apply organic EL elements to display elements such as flat panel displays, it is necessary to improve the luminous efficiency of the elements while ensuring stability during driving. In view of the above, the object of the present invention is to provide a practically useful organic EL element that is highly efficient and achieves low-voltage characteristics.

[0022] [Technical means to solve the problem]

[0023] Through diligent research, the inventors discovered that the aforementioned problem could be solved by using an organic electric field light-emitting element with a specific hybrid host material in the light-emitting layer, thus completing this invention.

[0024] That is, the present invention is an organic electric field light-emitting element, which is an organic electric field light-emitting element having multiple organic layers between opposing anodes and cathodes, and is characterized in that: the organic layer has at least one light-emitting layer, the light-emitting layer comprising two different host materials and a dopant material, one of the host materials being a compound represented by the following general formula (1), and the other of the host materials being a compound represented by the following general formula (2).

[0025] [Chemistry 1]

[0026]

[0027]

[0028] [Here, ring A is the heterocyclic ring represented by equation (1a), and ring A and adjacent rings are condensed at any position.]

[0029] X represents N or C-Ar', where at least one of X represents N;

[0030] Y represents O, S, N-Ar 3 or C-Ar 4 Ar 5 ;

[0031] Z 1 ~Z 4 Any one of them is a carbon atom bonded to a six-membered ring containing X, and the others and Z 5 ~Z 8 They can be represented independently as C-Ar' or N, and can be the same or different when there are multiple Ar's;

[0032] Ar, Ar' and Ar 1 ~Ar 5Each of these groups independently represents hydrogen, deuterium, halogen, cyano, nitro, alkyl with 1 to 20 carbon atoms, aralkyl with 7 to 38 carbon atoms, alkenyl with 2 to 20 carbon atoms, alkynyl with 2 to 20 carbon atoms, dialkylamino with 2 to 40 carbon atoms, diarylamino with 12 to 44 carbon atoms, diarylalkylamino with 14 to 76 carbon atoms, acyl with 2 to 20 carbon atoms, acyloxy with 2 to 20 carbon atoms, alkoxy with 1 to 20 carbon atoms, alkoxycarbonyl with 2 to 20 carbon atoms, alkoxycarbonyloxy with 2 to 20 carbon atoms, alkylsulfonyl with 1 to 20 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group with 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic group with 3 to 17 carbon atoms, or linked aromatic groups consisting of 2 to 5 of these aromatic rings; furthermore, when these groups have hydrogen atoms, the hydrogen atoms may also be substituted with deuterium or halogen.

[0033] a and b represent substitution numbers, and each independently represents an integer from 1 to 4; additionally, c represents a substitution number, and represents an integer from 1 to 2.

[0034] [Chemistry 2]

[0035]

[0036]

[0037] [Here, ring B is the heterocyclic ring represented by equation (2a), and ring B condenses with adjacent rings at any position.]

[0038] Ar 6 and Ar 7 Each of these groups independently represents hydrogen, deuterium, halogen, cyano, nitro, alkyl with 1 to 20 carbon atoms, aralkyl with 7 to 38 carbon atoms, alkenyl with 2 to 20 carbon atoms, alkynyl with 2 to 20 carbon atoms, dialkylamino with 2 to 40 carbon atoms, diarylamino with 12 to 44 carbon atoms, diarylalkylamino with 14 to 76 carbon atoms, acyl with 2 to 20 carbon atoms, acyloxy with 2 to 20 carbon atoms, alkoxy with 1 to 20 carbon atoms, alkoxycarbonyl with 2 to 20 carbon atoms, alkoxycarbonyloxy with 2 to 20 carbon atoms, alkylsulfonyl with 1 to 20 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group with 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic group with 3 to 17 carbon atoms, or linked aromatic groups consisting of 2 to 5 of these aromatic rings; furthermore, when these groups have hydrogen atoms, the hydrogen atoms may also be substituted with deuterium or halogen.

[0039] d and e represent substitution numbers, and are integers from 1 to 4 respectively; f represents substitution numbers, and is an integer from 1 to 2.

[0040] Ar 8Each of the following groups independently represents hydrogen, deuterium, halogen, cyano, nitro, alkyl with 1 to 20 carbon atoms, aralkyl with 7 to 38 carbon atoms, alkenyl with 2 to 20 carbon atoms, alkynyl with 2 to 20 carbon atoms, dialkylamino with 2 to 40 carbon atoms, diarylamino with 12 to 44 carbon atoms, diarylalkylamino with 14 to 76 carbon atoms, acyl with 2 to 20 carbon atoms, acyloxy with 2 to 20 carbon atoms, alkoxy with 1 to 20 carbon atoms, alkoxycarbonyl with 2 to 20 carbon atoms, alkoxycarbonyloxy with 2 to 20 carbon atoms, alkylsulfonyl with 1 to 20 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group with 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic group with 3 to 17 carbon atoms, or a linked aromatic group consisting of 2 to 5 of these aromatic rings.

[0041] Preferably, in the general formula (1), by Z 1 、or Z 2 Any one of them is connected to a six-membered ring containing X.

[0042] Preferably, in the general formula (1), Y is O or S.

[0043] Preferably, the general formula (1) is represented by any one of the following general formulas (4) to (8).

[0044] [Chemistry 3]

[0045]

[0046] [Here, X, Y, Ar, Ar] 1 Ar 2 Z 1 ~Z 8 a, b, and c have the same meaning as the general formula (1).

[0047] Preferably, in the general formulas (4) to (8), Z is used. 2 Connect to a six-membered ring containing X.

[0048] More preferably, in the general formulas (4) to (8), Ar 1 and Ar 2 It is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms, or a linked aromatic group consisting of 2 to 5 of these aromatic rings.

[0049] Preferably, the general formula (2) is represented by any one of the following general formulas (9) to (13).

[0050] [Chemistry 4]

[0051]

[0052] [Here, Ar] 8d, e, f, Ar 6 and Ar 7 [This has the same meaning as equation (2)]

[0053] In the general formulas (9) to (13), Ar 6 and Ar 7 Preferably, it is an aromatic hydrocarbon group with 6 to 10 carbon atoms, substituted or unsubstituted, an aromatic heterocyclic group with 3 to 17 carbon atoms, or a linked aromatic group consisting of 2 to 5 of these aromatic rings, and preferably Ar. 6 and Ar 7 At least one of them contains an aromatic heterocycle with 6 to 17 carbon atoms.

[0054] Preferably, the dopant material is a phosphorescent dopant material or a fluorescent dopant material containing thermally activated delayed fluorescence emission.

[0055] Here, a preferred embodiment of the organic electric field light-emitting element of the present invention is shown. That is, the organic electric field light-emitting element of the present invention includes a light-emitting layer having a mixed host material and a dopant material, wherein the mixed host material comprises two compounds. Specifically, as the mixed host material, the proportion of the compound represented by general formula (1) is preferably 10% by mass or more and less than 70% by mass, more preferably 20% by mass or more and less than 60% by mass, relative to the total of the compounds represented by general formula (1) and general formula (2). Furthermore, more preferably, the luminescent dopant material is an organometallic complex comprising at least one metal selected from the group consisting of ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold, or a fluorescent dopant material comprising thermally activated delayed fluorescence.

[0056] In addition, when manufacturing the organic electric field light-emitting element, it is suitable to have a process of mixing the compound represented by general formula (1) with the compound represented by general formula (2) to form a premix, and then depositing a host material containing the premix to form a light-emitting layer by vapor deposition.

[0057] In the method for manufacturing the organic electric field light-emitting element, it is suitable that the difference in temperature between the compound represented by general formula (1) and the compound represented by general formula (2) by 50% weight reduction is within 20°C.

[0058] To improve device characteristics, the materials used in the organic layers need to have high charge durability, especially in the light-emitting layer, where it is important to suppress exciton and charge leakage to the peripheral layers. In suppressing this charge / exciton leakage, it is effective to improve the offset of the light-emitting region in the light-emitting layer. This requires controlling the amount of two charges (electrons / holes) injected into the light-emitting layer or the amount of two charges transported within the light-emitting layer to a preferred range.

[0059] Here, the compounds represented by general formulas (1) and (2) used in this invention both have an indole-carbazole structure. The indole-carbazole structure is known to have high charge durability. It is believed that the compounds represented by general formula (1), by substituting the nitrogen-containing 6-membered ring with a condensed aromatic group in the indole-carbazole structure, improve charge, especially electron injection transport, and can be used to create low-voltage and stably driven organic EL elements. Furthermore, it is believed that by mixing indole-carbazole compounds represented by general formula (2), charge, especially hole injection transport, can be improved, and low-voltage and stably driven organic EL elements can be created. By changing the bonding pattern of the indole-carbazole ring or the type and number of substituents on the skeleton, charge injection transport can be controlled at a high level. Therefore, it is speculated that by combining the compounds represented by general formula (1) and general formula (2), the amount of two charges injected into the organic layer can be adjusted to a preferred range, and the offset of the luminescent region in the luminescent layer can be improved. In particular, in the case of delayed fluorescence EL devices or phosphorescent EL devices, since the lowest excitation triplet energy is sufficiently high for the excitation energy generated in the encapsulated light-emitting layer, no energy will flow out from the light-emitting layer, and it is possible to make low-voltage, high-efficiency, and long-life organic EL devices.

[0060] [The effects of the invention]

[0061] Therefore, the characteristics of organic EL elements can be improved through this invention, especially in terms of luminous efficiency and applied voltage, which can be improved compared with the past. Attached Figure Description

[0062] Figure 1 This is a schematic cross-sectional view showing an example of an organic EL element. Detailed Implementation

[0063] The organic EL element of the present invention has a structure consisting of an anode, an organic layer, and a cathode stacked together, and at least one layer of the organic layer includes a light-emitting layer formed using a specified organic electric field light-emitting element material. That is, the organic EL element has multiple organic layers between opposing anodes and cathodes, but at least one of the multiple layers is a light-emitting layer, and there may be multiple light-emitting layers. Moreover, at least one of the light-emitting layers includes two different host materials and a dopant material, wherein one of the host materials includes a compound represented by the general formula (1) described above (hereinafter referred to as the first host material), and the other includes a compound also represented by the general formula (2) described above (hereinafter referred to as the second host material). It is suitable that the light-emitting layer is formed in the form of a vapor-deposited layer containing a luminescent dopant material.

[0064] That is, the first host material contained in the light-emitting layer is selected from the compound represented by general formula (1), and the second host material is selected from the compound represented by general formula (2).

[0065] In general formula (1), X represents N or C-Ar', at least one of X represents N, but preferably two or more of X are N, and more preferably all of X are N.

[0066] a and b represent substitution numbers, and each independently represents an integer from 1 to 4, preferably 1 to 2, more preferably 1. c also represents a substitution number, and represents an integer from 1 to 2, preferably 1.

[0067] Z 1 ~Z 4 Any one of them is a carbon atom bonded to a six-membered ring containing X, and the others are Z. 1 ~Z 4 and Z 5 ~Z 8 C-Ar' or N can be represented independently, preferably C-Ar'. Furthermore, when there are multiple Ar', they can be the same or different.

[0068] In general formula (1), Ar, Ar' and Ar 1 ~Ar 5 Each of these groups independently represents hydrogen, deuterium, halogen, cyano, nitro, alkyl with 1 to 20 carbon atoms, aralkyl with 7 to 38 carbon atoms, alkenyl with 2 to 20 carbon atoms, alkynyl with 2 to 20 carbon atoms, dialkylamino with 2 to 40 carbon atoms, diarylamino with 12 to 44 carbon atoms, diarylalkylamino with 14 to 76 carbon atoms, acyl with 2 to 20 carbon atoms, acyloxy with 2 to 20 carbon atoms, alkoxy with 1 to 20 carbon atoms, alkoxycarbonyl with 2 to 20 carbon atoms, alkoxycarbonyloxy with 2 to 20 carbon atoms, alkylsulfonyl with 1 to 20 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group with 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic group with 3 to 17 carbon atoms, or linked aromatic groups consisting of 2 to 5 of these aromatic rings.

[0069] Among them, Ar 1 and Ar 2 More preferably, it is a substituted or unsubstituted aromatic hydrocarbon group having 6 to 10 carbon atoms, or a linked aromatic group consisting of 2 to 5 of these aromatic rings.

[0070] In addition, Ar, Ar' and Ar 3 ~Ar 5Preferably, it is hydrogen, deuterium, an alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings. More preferably, it is hydrogen, deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings.

[0071] Furthermore, in this specification, "linked aromatic group" refers to a group formed by the linkage of aromatic rings of aromatic hydrocarbon groups and / or aromatic heterocyclic groups through single bonds. Specifically, it represents a group formed by the linkage of 2 to 5 aromatic rings of substituted or unsubstituted aromatic hydrocarbon groups having 6 to 30 carbon atoms, or the linkage of 2 to 5 aromatic rings of substituted or unsubstituted aromatic heterocyclic groups having 3 to 17 carbon atoms, or a group formed by the linkage of aromatic rings of these aromatic hydrocarbon groups with 2 to 5 aromatic rings of aromatic heterocyclic groups. These linkages can be linear or branched, and the aromatic rings can be the same or different.

[0072] As Ar, Ar' and Ar 1 ~Ar 5Specific examples of halogen, cyano, nitro, alkyl with 1-20 carbon atoms, aralkyl with 7-38 carbon atoms, alkenyl with 2-20 carbon atoms, alkynyl with 2-20 carbon atoms, dialkylamino with 2-40 carbon atoms, diarylamino with 12-44 carbon atoms, diarylalkylamino with 14-76 carbon atoms, acyl with 2-20 carbon atoms, acyloxy with 2-20 carbon atoms, alkoxy with 1-20 carbon atoms, alkoxycarbonyl with 2-20 carbon atoms, alkoxycarbonyloxy with 2-20 carbon atoms, and alkylsulfonyl with 1-20 carbon atoms include: methyl, ethyl, propyl, butyl, and pentyl. Alkyl groups including cyclopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; aralkyl groups including phenylmethyl, phenylethyl, phenyleicosyl, naphthylmethyl, anthraceneylmethyl, phenanthrenemethyl, and pyreneylmethyl; alkenyl groups including vinyl, propenyl, butenyl, pentenyl, decenyl, and eicosene; alkynyl groups including ethynyl, propynyl, butynyl, pentyynyl, decynyl, and eicosene; and dimethylamino, ethylmethylamino, and diethylamino. Dialkylamino groups such as dipropylamino, dibutylamino, dipentylamino, didecylamino, and di-eicoalkylamino; diarylamino groups such as diphenylamino, naphthylphenylamino, dinaphthylamino, dianthrylamino, diphenylamino, and dipyreneamino; diarylalkylamino groups such as diphenylmethylamino, diphenylethylamino, phenylmethylphenylethylamino, dinaphthylmethylamino, dianthrylmethylamino, and diphenylmethylamino; acyl groups such as acetyl, propionyl, butyryl, valeryl, and benzoyl; and acetyloxy, propionyloxy, butyryloxy, valeryloxy, and benzyl... Acyloxy groups such as formyloxy, methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy, octoxy, nonoxy, and decoxy, alkoxy groups such as methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, and pentoxycarbonyl, alkoxycarbonyloxy groups such as methoxycarbonyloxy, ethoxycarbonyloxy, propoxycarbonyloxy, butoxycarbonyloxy, and pentoxycarbonyloxy, alkylsulfonyl groups such as methylsulfonyl, ethylsulfonyl, propylsulfonyl, butylsulfonyl, and pentylsulfonyl, cyano, nitro, fluoro, and toluenesulfonyl, etc. Preferably, they are methyl, ethyl, propyl, butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, undecyl, or dodecyl.

[0073] As unreplaced Ar, Ar', and Ar 3 ~Ar 5Specific examples of aromatic hydrocarbon groups, aromatic heterocyclic groups, or groups linked with aromatic groups include: aromatic groups formed by removing one H from compounds composed of benzene, naphthalene, pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, isoxazole, oxazole, oxadiazole, quinoline, isoquinoline, quinoxoline, quinazoline, benzotriazine, phthalazine, tetrazolium, indole, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benzimazole, benzotriazole, benzoisothiazole, benzothiadiazole, dibenzofuran, dibenzothiophene, dibenzoselenophenol, carbazole, or 2 to 5 of these linked groups. Preferably, the following are examples of aromatic groups formed by removing one H from a compound composed of benzene, pyridine, pyrimidine, triazine, thiophene, isothiazol, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, isoxazole, oxazole, oxiadiazole, quinoline, isoquinoline, quinoxoline, quinazoline, benzotriazine, phthalazine, tetrazolium, indole, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benzimazole, benzotriazole, benzoisothiazole, benzothiadiazole, dibenzofuran, dibenzothiophene, dibenzoselenophenol, carbazole, or 2 to 5 of these linked together. More preferably, an aromatic group is formed by removing one H from a compound consisting of benzene, pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, isoxazole, oxazole, oxadiazole, dibenzofuran, dibenzothiophene, carbazole, or 2 to 5 of these linked together.

[0074] As an irreplaceable Ar 1 and Ar 2 Specific examples of aromatic hydrocarbon groups, aromatic heterocyclic groups, or groups linked to aromatic groups, with unsubstituted Ar and unsubstituted Ar. 3 ~Ar 5 The same, preferably, are aromatic groups formed by removing one H from compounds composed of benzene, naphthalene, pyridine, pyrimidine, triazine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, isoxazole, oxazole, oxadiazole, quinoline, isoquinoline, quinoxoline, quinazoline, benzotriazine, phthalazine, tetrazolium, indole, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benzimazole, benzotriazole, benzoisothiazole, benzothiadiazole, dibenzofuran, dibenzothiophene, dibenzoselenophenol, carbazole, or 2 to 5 of these linked compounds. More preferably, aromatic groups formed by removing one H from compounds composed of benzene, naphthalene, or 2 to 5 of these linked compounds.

[0075] In this specification, the unsubstituted aromatic hydrocarbon group or aromatic heterocyclic group as described above may also have substituents. When substituents are present, the substituents are cyano, aliphatic hydrocarbon group with 1 to 10 carbon atoms, or diarylamino with 12 to 44 carbon atoms.

[0076] Here, when the substituent is an aliphatic hydrocarbon group with 1 to 10 carbon atoms, it can be linear, branched, or cyclic.

[0077] Furthermore, the number of substituents is preferably 0 to 5, and more preferably 0 to 2. When calculating the number of carbons in aromatic hydrocarbon groups and aromatic heterocyclic groups with substituents, the number of carbons in the substituents is not included. However, it is preferable that the total number of carbons, including the number of carbons in the substituents, meets the aforementioned range. Furthermore, when these groups have hydrogen atoms, the hydrogen atoms may also be substituted with deuterium or halogens.

[0078] Specific examples of the substituents include: cyano, methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, diphenylamino, naphthylphenylamino, dinaphthylamino, dianthrylamino, diphenoxyamino, dipyreneamino, etc. Preferably, the substituents include: cyano, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, diphenylamino, naphthylphenylamino, or dinaphthylamino.

[0079] The following are specific examples of compounds represented by general formula (1), but are not limited to these.

[0080] [Chemistry 5]

[0081]

[0082] [Chemistry 6]

[0083]

[0084] [Chemistry 7]

[0085]

[0086] [Chemistry 8]

[0087]

[0088] [Chemistry 9]

[0089]

[0090] [Chemistry 10]

[0091]

[0092] [Chemistry 11]

[0093]

[0094] [Chemistry 12]

[0095]

[0096] [Chemistry 13]

[0097]

[0098] [Chemistry 14]

[0099]

[0100] [Chemistry 15]

[0101]

[0102] [Chemistry 16]

[0103]

[0104] [Chemistry 17]

[0105]

[0106] [Chemistry 18]

[0107]

[0108] In general formula (2), Ar 6 and Ar 7 Each of the following is independently hydrogen, deuterium, halogen, cyano, nitro, alkyl with 1-20 carbon atoms, aralkyl with 7-38 carbon atoms, alkenyl with 2-20 carbon atoms, alkynyl with 2-20 carbon atoms, dialkylamino with 2-40 carbon atoms, diarylamino with 12-44 carbon atoms, diarylalkylamino with 14-76 carbon atoms, acyl with 2-20 carbon atoms, acyloxy with 2-20 carbon atoms, alkoxy with 1-20 carbon atoms, alkoxycarbonyl with 2-20 carbon atoms, alkoxycarbonyloxy with 2-20 carbon atoms, and alkane with 1-20 carbon atoms. The aromatic group may contain an alkyl sulfonyl group, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a linked aromatic group consisting of 2 to 5 of these aromatic hydrocarbon groups and aromatic heterocyclic groups, preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 6 to 17 carbon atoms, or a linked aromatic group consisting of 2 to 5 of these aromatic hydrocarbon groups and aromatic heterocyclic groups, more preferably Ar. 6 and Ar 7 At least one of them contains one or more substituted or unsubstituted aromatic heterocycles with 6 to 17 carbon atoms.

[0109] As an irreplaceable Ar 6 and Ar 7 Specific examples of aromatic hydrocarbon groups, aromatic heterocyclic groups, or groups linked with aromatic groups include: aromatic groups formed by removing one H from compounds composed of benzene, naphthalene, pyridine, pyrimidine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, isoxazole, oxazole, oxadiazole, quinoline, isoquinoline, quinoxoline, quinazoline, benzotriazine, phthalazine, tetrazolium, indole, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benzimazole, benzotriazole, benzoisothiazole, benzothiadiazole, dibenzofuran, dibenzothiophene, dibenzoselenophenol, carbazole, or 2 to 5 of these linked groups. Preferably, an aromatic group is formed by removing one hydrogen atom from a compound consisting of benzene, naphthalene, triphenylene, pyridine, pyrimidine, thiophene, isothiazole, thiazole, pyridazine, pyrrole, pyrazole, imidazole, triazole, thiadiazole, pyrazine, furan, isoxazole, oxazole, oxadiazole, quinoline, isoquinoline, quinoxoline, quinazoline, benzotriazine, phthalazine, tetrazolium, indole, benzofuran, benzothiophene, benzoxazole, benzothiazole, indazole, benzimazole, benzotriazole, benzoisothiazole, benzothiadiazole, dibenzofuran, dibenzothiophene, dibenzoselenophenol, carbazole, or 2 to 5 of these linked compounds. More preferably, an aromatic group is formed by removing one hydrogen atom from a compound consisting of benzene, carbazole, or 2 to 5 of these linked compounds.

[0110] d and e represent substitution numbers, and are integers from 1 to 4, preferably 1 to 2, and more preferably 1. f also represents substitution numbers, and is an integer from 1 to 2, preferably 1.

[0111] Ar 8 Each of these groups independently represents hydrogen, deuterium, halogen, cyano, nitro, alkyl with 1 to 20 carbon atoms, aralkyl with 7 to 38 carbon atoms, alkenyl with 2 to 20 carbon atoms, alkynyl with 2 to 20 carbon atoms, dialkylamino with 2 to 40 carbon atoms, diarylamino with 12 to 44 carbon atoms, diarylalkylamino with 14 to 76 carbon atoms, acyl with 2 to 20 carbon atoms, acyloxy with 2 to 20 carbon atoms, alkoxy with 1 to 20 carbon atoms, alkoxycarbonyl with 2 to 20 carbon atoms, alkoxycarbonyloxy with 2 to 20 carbon atoms, alkylsulfonyl with 1 to 20 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group with 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic group with 3 to 17 carbon atoms, or linked aromatic groups consisting of 2 to 5 of these aromatic rings.

[0112] Additionally, Ar 8Preferably, it is hydrogen, deuterium, an alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings. More preferably, it is hydrogen, deuterium, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 18 carbon atoms, a substituted or unsubstituted aromatic heterocyclic group having 3 to 12 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings.

[0113] As Ar 8 The specific examples are the same as those described in Ar.

[0114] As Ar 6 and Ar 7 Specific examples of alkyl groups having 1 to 20 carbon atoms, aralkyl groups having 7 to 38 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, dialkylamino groups having 2 to 40 carbon atoms, diarylamino groups having 12 to 44 carbon atoms, diarylalkylamino groups having 14 to 76 carbon atoms, acyl groups having 2 to 20 carbon atoms, acyloxy groups having 2 to 20 carbon atoms, alkoxy groups having 1 to 20 carbon atoms, alkoxycarbonyl groups having 2 to 20 carbon atoms, alkoxycarbonyloxy groups having 2 to 20 carbon atoms, and alkylsulfonyl groups having 1 to 20 carbon atoms, with Ar, Ar', and Ar 1 ~Ar 5 The situation is the same. Furthermore, in this invention, in order to form a light-emitting layer comprising two host materials, the compound represented by general formula (1) is different from the compound represented by general formula (2). Therefore, for the purpose of avoiding repetition, Ar in general formula (2) 6 and Ar 7 It cannot be represented by the following formula (3).

[0115] [Chemistry 19]

[0116]

[0117] [Here, * indicates the connection position with general formula (2), X and Ar] 1 [This has the same meaning as general formula (1)]

[0118] The following are specific examples of compounds represented by general formula (2), but are not limited to these.

[0119] [Chemistry 20]

[0120]

[0121] [Chemistry 21]

[0122]

[0123] [Chemistry 22]

[0124]

[0125] [Chemistry 23]

[0126]

[0127] [Chemistry 24]

[0128]

[0129] [Chemistry 25]

[0130]

[0131] [Chemistry 26]

[0132]

[0133] [Chemistry 27]

[0134]

[0135] [Chemistry 28]

[0136]

[0137] [Chemistry 29]

[0138]

[0139] [Chemistry 30]

[0140]

[0141] [Chemistry 31]

[0142]

[0143] [Chemistry 32]

[0144]

[0145] [Chemistry 33]

[0146]

[0147] [Chemistry 34]

[0148]

[0149] [Chemistry 35]

[0150]

[0151] [Chemistry 36]

[0152]

[0153] [Chemistry 37]

[0154]

[0155] [Chemistry 38]

[0156]

[0157] [Chemistry 39]

[0158]

[0159] [Chemistry 40]

[0160]

[0161] [Chemistry 41]

[0162]

[0163] The organic electric field light-emitting element of the present invention has a light-emitting layer comprising a compound represented by general formula (1), a compound represented by general formula (2), and a dopant material. However, the light-emitting layer may also contain aliphatic organic compounds, aromatic hydrocarbon compounds, aromatic heterocyclic compounds, organometallic complexes, etc., as other components. When other components are included, the total proportion of the other components in the light-emitting layer is preferably less than 30% by mass, more preferably less than 10% by mass.

[0164] Furthermore, relative to the total of the compounds represented by general formula (1) and the compounds represented by general formula (2), the proportion of the compounds represented by general formula (1) is preferably 10% by mass or more and less than 70% by mass, more preferably 20% by mass or more and less than 60% by mass.

[0165] Regarding the luminescent dopant material, it is preferably an organometallic complex comprising at least one metal selected from the group consisting of ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum and gold, or a fluorescent luminescent dopant material comprising thermally activated delayed fluorescence.

[0166] Regarding the light-emitting layer of the organic electric field light-emitting element of the present invention, it can be formed by evaporating a first host material, a second host material, or a dopant material from an evaporation source, or by dissolving or dispersing these materials in a solvent and forming them using spin coating, bar coating, spray coating, inkjet coating, printing, or other methods.

[0167] When forming the light-emitting layer of the organic electric field light-emitting element of the present invention using vapor deposition, vapor deposition can also be performed from different vapor deposition sources. Preferably, the materials are premixed to form a premix before vapor deposition, and the light-emitting layer is formed by simultaneously vapor deposition of the premix from one vapor deposition source. In this case, luminescent dopant materials required for forming the light-emitting layer or other host materials as needed can also be mixed into the premix. However, when there is a large difference in the temperature at which the desired vapor pressure is formed, vapor deposition can also be performed from other vapor deposition sources.

[0168] When forming the light-emitting layer of the organic electric field light-emitting element of the present invention using a printing method, the light-emitting layer ink can be prepared by dissolving or dispersing the compound represented by general formula (1), the compound represented by general formula (2), and the dopant material in a solvent, and the film can be formed using the printing method.

[0169] Next, the structure of the organic EL element of the present invention will be described with reference to the accompanying drawings, but the structure of the organic EL element of the present invention is not limited thereto.

[0170] Figure 1 This is a cross-sectional view showing a typical organic EL element structure used in this invention. 1 represents a substrate, 2 represents an anode, 3 represents a hole injection layer, 4 represents a hole transport layer, 5 represents a light-emitting layer, 6 represents an electron transport layer, and 7 represents a cathode. The organic EL element of this invention may have an exciton blocking layer adjacent to the light-emitting layer, and may also have an electron blocking layer between the light-emitting layer and the hole injection layer. The exciton blocking layer may be inserted to either the anode side or the cathode side of the light-emitting layer, or simultaneously to both sides. In the organic EL element of this invention, an anode, a light-emitting layer, and a cathode are required layers, but in addition to these required layers, a hole injection transport layer and an electron injection transport layer may also be included, and a hole blocking layer may be present between the light-emitting layer and the electron injection transport layer. Furthermore, a hole injection transport layer refers to either or both of the hole injection layer and the hole transport layer, and an electron injection transport layer refers to either or both of the electron injection layer and the electron transport layer.

[0171] It can also be used for Figure 1 In the opposite structure, where the cathode 7, electron transport layer 6, light-emitting layer 5, hole transport layer 4, and anode 2 are sequentially stacked on the substrate 1, layers can be added or omitted as needed.

[0172] -Substrate-

[0173] The organic EL element of the present invention is preferably supported on a substrate. The substrate is not particularly limited, as long as it is a substrate that has been used for organic EL elements before, such as a substrate containing glass, transparent plastic, quartz, etc.

[0174] -anode-

[0175] As the anode material in an organic electroluminescent (EL) element, materials containing metals, alloys, electrically conductive compounds, or mixtures thereof with a high work function (4 eV or higher) are preferably used. Specific examples of such electrode materials include metals such as Au; conductive transparent materials such as CuI, indium tin oxide (ITO), SnO2, and ZnO. Alternatively, amorphous materials such as IDIXO (In2O3-ZnO) that can be formed into transparent conductive films can also be used. The anode can be formed into a thin film using methods such as vapor deposition or sputtering, and a pattern of the desired shape can be formed using photolithography. Alternatively, when pattern precision is not critical (around 100 μm or higher), a pattern can be formed by separating the desired shape from the electrode material during vapor deposition or sputtering. Alternatively, when using a coatable substance such as an organic conductive compound, wet film formation methods such as printing or coating can be used. When light is emitted from the anode, it is ideal to have a transmittance greater than 10%, and the sheet resistance of the anode is preferably less than several hundred Ω / Y. The film thickness also depends on the material, but is usually selected in the range of 10 nm to 1000 nm, preferably 10 nm to 200 nm.

[0176] -cathode-

[0177] On the other hand, as cathode materials, materials comprising metals (electron-injecting metals), alloys, electrically conductive compounds, or mixtures thereof with low work functions (below 4 eV) can be used. Specific examples of such electrode materials include: sodium, sodium-potassium alloys, magnesium, lithium, magnesium / copper mixtures, magnesium / silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / alumina (Al₂O₃) mixtures, indium, lithium / aluminum mixtures, rare earth metals, etc. Among these, in terms of electron injection performance and durability against oxidation, mixtures of electron-injecting metals and second metals that are more stable and have a larger work function than the first metal are suitable, such as magnesium / silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / alumina mixtures, lithium / aluminum mixtures, aluminum, etc. Cathodes can be fabricated by forming thin films from these cathode materials using methods such as evaporation or sputtering. Furthermore, as a cathode, the sheet resistance is preferably several hundred Ω / Y or less, and the film thickness is typically selected in the range of 10 nm to 5 μm, preferably 50 nm to 200 nm. Furthermore, in order for the emitted light to pass through, if either the anode or cathode of the organic EL element is transparent or translucent, the luminous brightness will be increased, which is appropriate.

[0178] Furthermore, after forming the metal on the cathode with a film thickness of 1 nm to 20 nm, a conductive transparent material listed in the description of the anode is formed on it, thereby making a transparent or semi-transparent cathode. By applying the method described above, an element in which both the anode and cathode are permeable can be made.

[0179] -Emitting Layer-

[0180] The light-emitting layer is a layer that emits light after generating excitons by recombination of holes and electrons injected from the anode and cathode, respectively, and the light-emitting layer includes a compound represented by general formula (1), a compound represented by general formula (2), and a light-emitting dopant material.

[0181] The compounds represented by general formula (1) and general formula (2) can be suitably used as the host material of the luminescent layer. One or more compounds represented by general formula (1) may be used. Similarly, one or more compounds represented by general formula (2) may be used.

[0182] As needed, one or more known main materials may also be used, and the amount used relative to the total amount of the main materials of the compound represented by general formula (1) and the compound represented by general formula (2) may be set to 50% by mass or less, preferably 25% by mass or less.

[0183] When using a compound represented by general formula (1) premixed with a compound represented by general formula (2), in order to produce an organic EL element with good reproducibility and properties, it is ideal to reduce the weight of each compound by 50% at a temperature (T). 50 The difference is small. The 50% weight loss temperature refers to the temperature at which a 50% weight loss occurs when the temperature is increased from room temperature to 550°C at a rate of 10°C per minute under reduced pressure (1 Pa) nitrogen flow. It is believed that vaporization caused by evaporation or sublimation is most intense near this temperature.

[0184] The compound represented by general formula (1) and the compound represented by general formula (2) preferably have a temperature difference of less than 30°C, more preferably less than 20°C, between the 50% weight reduction temperature and the compound represented by general formula (2). As a premixing method, known methods such as pulverization and mixing can be used, and ideally, the mixture should be as uniform as possible. Furthermore, the 50% weight reduction temperature difference refers to an absolute value.

[0185] When using multiple base materials, each base material can be vapor-deposited from different vapor deposition sources, or a premixed mixture can be prepared by pre-mixing before vapor deposition, thereby allowing multiple base materials to be vapor-deposited simultaneously from one vapor deposition source.

[0186] Ideally, premixing methods should aim to achieve the most uniform mixing possible. Examples include pulverization and mixing, heating and melting under reduced pressure or inert gas conditions such as nitrogen, or sublimation, but these methods are not the only options.

[0187] The main body and its premixed mixture can be in the form of powder, rod, or granules.

[0188] When using a phosphorescent dopant material as the luminescent dopant material, the phosphorescent dopant material may contain an organometallic complex comprising at least one metal selected from ruthenium, rhodium, palladium, silver, rhenium, osmium, iridium, platinum, and gold. Specifically, iridium complexes described in Journal of the American Chemical Society (J. Am. Chem. Soc.) 2001, 123, 4304 or Japanese Patent Publication No. 2013-53051 may be used, but are not limited to these.

[0189] The light-emitting layer may contain only one phosphorescent dopant material, or it may contain two or more phosphorescent dopant materials. The content of the phosphorescent dopant material relative to the host material is preferably 0.10 wt% to 30 wt%, more preferably 1.0 wt% to 20 wt%.

[0190] There are no particular limitations on phosphorescent dopant materials; specifically, examples such as the following can be cited.

[0191] [Chemistry 42]

[0192]

[0193] [Chemistry 43]

[0194]

[0195] When using fluorescent dopant materials as luminescent dopant materials, there are no particular limitations on the fluorescent dopant materials. Examples include: benzoxazole derivatives, benzothiazole derivatives, benzimidazole derivatives, styrene-based benzene derivatives, polyphenyl derivatives, diphenylbutadiene derivatives, tetraphenylbutadiene derivatives, naphthalene dicarboximide derivatives, coumarin derivatives, condensed aromatic compounds, perinone derivatives, oxadiazole derivatives, oxazine derivatives, aldazine derivatives, pyrrolidine derivatives, cyclopentadiene derivatives, bis(styrene)-anthracene derivatives, quinacridone derivatives, pyrrolopyridine derivatives, thiadiazopyridine derivatives, styrene-based amine derivatives, diketone-pyrrolopyrrole derivatives, aromatic secondary methyl compounds, metal complexes of 8-hydroxyquinoline derivatives or metal complexes of pyrrole methylene derivatives, rare earth complexes, transition metal complexes, etc., polymer compounds such as polythiophene, polyphenylene, and polyphenylene oxide, organosilanes, etc. Preferably, the derivatives include condensed aromatic derivatives, styryl derivatives, diketopyrrolopyrrole derivatives, oxazine derivatives, pyrrole methylene metal complexes, transition metal complexes, or lanthanide complexes. More preferably, the derivatives include naphthalene, pyrene, 1,2-benzophenanthrene, triphenylene, benzo[c]phenanthrene, benzo[a]anthracene, pentaphenyl, perylene, fluoranthracene, acenaphthene, dibenzo[a,j]anthracene, dibenzo[a,h]anthracene, benzo[a]naphthalene, hexaphenyl, naphtho[2,1-f]isoquinoline, α-naphthaphenanthridine, phenanthrazole, quinolino[6,5-f]quinoline, benzonaphtho[2,3-b]thiophene, etc. These may also have alkyl, aryl, aromatic heterocyclic groups, or diarylamino groups as substituents.

[0196] The luminescent layer may contain only one type of fluorescent dopant material, or it may contain two or more types of fluorescent dopant materials. The content of the fluorescent dopant material relative to the host material is preferably 0.10 wt% to 20 wt%, more preferably 1.0 wt% to 10 wt%.

[0197] When using thermally activated delayed fluorescence (TEF) dopants as luminescent dopants, there are no particular limitations on the types of TEF dopants that can be used. Examples include: metal complexes such as tin complexes or copper complexes; indole-carbazole derivatives as described in WO2011 / 070963; cyanobenzene derivatives and carbazole derivatives as described in Nature 2012, 492, 234; and phenazine derivatives, oxadiazole derivatives, triazole derivatives, sulfone derivatives, phenoxazine derivatives, and acridine derivatives as described in Nature Photonics 2014, 8, 326.

[0198] There are no particular limitations on thermally activated delayed fluorescence dopants; specifically, examples such as the following can be cited.

[0199] [Chemistry 44]

[0200]

[0201] [Chemistry 45]

[0202]

[0203] The luminescent layer may contain only one type of thermally activated delayed fluorescence (TEF) dopant material, or it may contain two or more types of TEF dopant materials. Furthermore, the TEF dopant material may be used in combination with a phosphorescent dopant material or a fluorescent dopant material. The content of the TEF dopant material relative to the host material is preferably 0.10% to 50% by mass, more preferably 1.0% to 30% by mass.

[0204] -Injection Layer-

[0205] An injection layer is a layer placed between the electrode and the organic layer to reduce the driving voltage or increase the luminous brightness. There are hole injection layers and electron injection layers, which can exist between the anode and the luminescent layer or hole transport layer, and between the cathode and the luminescent layer or electron transport layer. The injection layer can be set as needed.

[0206] -hole blocking layer-

[0207] In a broad sense, a hole blocking layer functions as an electron transport layer. It includes hole-blocking materials that can transport electrons but have a significantly lower ability to transport holes. By transporting electrons and blocking holes, it can increase the recombination probability of electrons and holes in the light-emitting layer.

[0208] Known hole-blocking layer materials can be used in the hole-blocking layer, preferably containing compounds represented by general formula (1).

[0209] -Electron blocking layer-

[0210] In a broad sense, the electron blocking layer functions as a hole transport layer, increasing the probability of electrons and holes recombinating in the luminescent layer by transporting holes and blocking electrons.

[0211] As the material for the electron blocking layer, known electron blocking layer materials can be used, and hole transport layer materials described later can also be used as needed. The film thickness of the electron blocking layer is preferably 3 nm to 100 nm, more preferably 5 nm to 30 nm.

[0212] -Exciton blocking layer-

[0213] An exciton blocking layer is a layer used to prevent excitons generated by the recombination of holes and electrons in the light-emitting layer from diffusing into the charge transport layer. By inserting this layer, excitons can be efficiently sealed into the light-emitting layer, thereby improving the luminous efficiency of the device. In devices with two or more adjacent light-emitting layers, the exciton blocking layer can be inserted between two adjacent light-emitting layers.

[0214] As the material for the exciton blocking layer, known exciton blocking layer materials can be used. For example, 1,3-dicarbazolylbenzene (mCP) or bis(2-methyl-8-hydroxyquinoline)-4-phenylphenol aluminum (III) (BAlq) can be used.

[0215] -Hole transport layer-

[0216] A hole transport layer is a hole transport material that has the function of transporting holes. A hole transport layer can be a single layer or multiple layers.

[0217] The hole transport material is any material that possesses either hole injection or transport or electron barrier properties, and can be either organic or inorganic. In the hole transport layer, any compound selected from previously known compounds can be used. Examples of such hole transport materials include: porphyrin derivatives, arylamine derivatives, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrene-anthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, and conductive polymeric oligomers, particularly thiophene oligomers. Porphyrin derivatives, arylamine derivatives, and styrene-anthracene derivatives are preferred, and arylamine derivatives are more preferred.

[0218] -Electron transport layer-

[0219] An electron transport layer consists of materials that can transport electrons, and can be a single layer or multiple layers.

[0220] As an electron transport material (and sometimes also a hole blocking material), it only needs to have the function of transporting electrons injected from the cathode to the emitting layer. The electron transport layer can be any of the previously known compounds, such as: polycyclic aromatic derivatives of naphthalene, anthracene, phenanthroline, etc.; tris(8-hydroxyquinoline)aluminum(III) derivatives; phosphine oxide derivatives; nitro-substituted fluorene derivatives; diphenylquinone derivatives; thiamethane dioxide derivatives; carbodiimide; fluorenemethane derivatives; anthraquinone dimethane and anthrone derivatives; bipyridine derivatives; quinoline derivatives; oxadiazole derivatives; benzimidazole derivatives; benzothiazole derivatives; indolecarbazole derivatives, etc. Furthermore, polymers incorporating these materials into polymer chains or using these materials as the backbone of polymers can also be used.

[0221] Example

[0222] The present invention will be described in more detail below through embodiments, but the present invention is not limited to these embodiments and can be implemented in various forms as long as it does not depart from its spirit.

[0223] The compounds used in the examples and comparative examples are shown below.

[0224] [Chemistry 46]

[0225]

[0226] In Table 1, compounds represented by general formula (1)-1, compound (1)-3, etc., which are compounds represented by the general formula (1), are listed first and together with compounds represented by general formula (2), and the 50% weight reduction temperature (T) of compound A and compound C. 50 Here, the 50% weight reduction temperature is the temperature at which 50% weight reduction occurs when the temperature is increased from room temperature to 550°C at a rate of 10°C per minute in a TG-DTA determination under reduced pressure (1 Pa) nitrogen flow.

[0227] [Table 1]

[0228] compound <![CDATA[T 50 [℃]]]> (1)-1 290 (1)-2 310 (1)-3 280 (1)-31 319 (2)-6 265 (2)-82 300 (2)-84 308 Compound A 271 Compound C 312

[0229] Example 1

[0230] On a glass substrate with an ITO-containing anode having a film thickness of 110 nm, vacuum evaporation was performed at a vacuum degree of 4.0 × 10⁻⁶. -5Pa was used to stack the thin films. First, HAT-CN was formed on ITO with a thickness of 25 nm as a hole injection layer. Next, NPD was formed with a thickness of 30 nm as a hole transport layer. Next, HT-1 was formed with a thickness of 10 nm as an electron blocking layer. Next, compound (1)-1 as the first host material, compound (2)-6 as the second host material, and Ir(ppy)3 as the light-emitting dopant material were co-deposited from different evaporation sources to form a light-emitting layer with a thickness of 40 nm. At this time, the concentration of Ir(ppy)3 was 10% by mass, and the concentration of the mixed host material containing the first host material and the second host material was 90% by mass. Specifically, the co-deposition was performed under the evaporation conditions that the mass ratio of the first host material to the second host material was 30:70. Next, ET-1 was formed with a thickness of 20 nm as an electron transport layer. Then, LiF was formed on the electron transport layer with a thickness of 1 nm as an electron injection layer. Finally, Al is formed on the electron injection layer to a thickness of 70 nm as a cathode, thereby fabricating an organic EL device.

[0231] Examples 2 to 6

[0232] In Example 1, the compounds shown in Table 2 were used as the first and second host materials, and the organic EL element was fabricated in the same manner as in Example 1.

[0233] Examples 7 to 13

[0234] In Example 1, the compounds shown in Table 2 were used as the first and second host materials, and co-evaporation was performed with the mass ratio of the first host material to the second host material being the values ​​shown in Table 2. Otherwise, the organic EL element was fabricated in the same manner as in Example 1.

[0235] Examples 14 to 18

[0236] In Example 1, the compounds shown in Table 2 were used as the first and second host materials. The first host material and the second host material were mixed in advance to form a premix, and the premix was deposited from a vapor deposition source. Otherwise, the organic EL element was fabricated in the same manner as in Example 1.

[0237] Comparative Examples 1 to 4

[0238] In Example 1, the compounds listed in Table 2 were used alone as the main material, and the organic EL element was fabricated in the same manner as in Example 1. The thickness of the light-emitting layer and the concentration of the light-emitting dopant were the same as in Example 1.

[0239] Comparative Examples 5 to 10

[0240] In Example 1, the compounds shown in Table 2 were used as the first and second host materials, and the organic EL element was fabricated in the same manner as in Example 1.

[0241] Comparative Examples 11 to 13

[0242] In Example 1, the compounds shown in Table 2 were used as the first and second host materials. The first and second host materials were mixed in advance to form a premix, and the premix was vapor-deposited from a vapor deposition source. Otherwise, the organic EL element was fabricated in the same manner as in Example 1.

[0243] The evaluation results of the fabricated organic EL elements are shown in Table 2.

[0244] In the table, brightness, driving voltage, and power efficiency are based on a driving current of 20mA / cm. 2 The value at that time is the initial characteristic. LT70 is the time it takes for the initial brightness to decay to 70%, representing the lifetime characteristic.

[0245] [Table 2]

[0246]

[0247] In Table 2, a comparison of the embodiments of the present invention with Comparative Examples 1 to 4 shows that the lifetime characteristics are significantly improved by using a hybrid host material. Furthermore, a comparison of the embodiments of the present invention with Comparative Examples 5 to 13 shows that the organic EL element using the combination of host materials disclosed in the present invention achieves both low driving voltage and high brightness in both co-evaporation and pre-mixing cases, significantly improving power efficiency. Additionally, it is evident that the lifetime characteristics are also excellent.

Claims

1. An organic electric field light-emitting element, comprising an organic electric field light-emitting element having multiple organic layers between the anode and the cathode, characterized in that: The organic layer has at least one light-emitting layer comprising two different host materials and a dopant material, one of the host materials being a compound represented by the following general formula (1), and the other of the host materials being a compound represented by the following general formula (2). Here, ring A is the heterocyclic ring represented by equation (1a), and ring A and the adjacent rings are condensed at any position. X represents N or C-Ar', where at least one of X represents N; Y represents O, S, N-Ar 3 , or C-Ar 4 Ar 5 ; Z 1 ~Z 4 any one of Z 5 ~Z 8 each independently represents C-Ar', or N, which can be the same or different in the presence of a plurality of Ar'. Ar, Ar' and Ar 1 ~Ar 5 Each of the following groups independently represents hydrogen, deuterium, halogen, cyano, nitro, alkyl with 1-20 carbon atoms, aralkyl with 7-38 carbon atoms, alkenyl with 2-20 carbon atoms, alkynyl with 2-20 carbon atoms, dialkylamino with 2-40 carbon atoms, diarylamino with 12-44 carbon atoms, diarylalkylamino with 14-76 carbon atoms, acyl with 2-20 carbon atoms, acyloxy with 2-20 carbon atoms, alkoxy with 1-20 carbon atoms, and alkoxy with 2-20 carbon atoms. The aromatic group may be composed of a carbonyl group, an alkoxycarbonyloxy group having 2 to 20 carbon atoms, an alkylsulfonyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms (substituted or unsubstituted), an aromatic heterocyclic group having 3 to 17 carbon atoms (substituted or unsubstituted), or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings; furthermore, if these groups have hydrogen atoms, the hydrogen atoms may also be substituted with deuterium or halogens. a and b represent substitution numbers, and each independently represents an integer from 1 to 4; in addition, c represents substitution number, and represents an integer from 1 to 2. Here, ring B is the heterocyclic ring represented by equation (2a), and ring B condenses with adjacent rings at any position. Ar 6 and Ar 7 Each of the following groups independently represents hydrogen, deuterium, halogen, cyano, nitro, alkyl with 1-20 carbon atoms, aralkyl with 7-38 carbon atoms, alkenyl with 2-20 carbon atoms, alkynyl with 2-20 carbon atoms, dialkylamino with 2-40 carbon atoms, diarylamino with 12-44 carbon atoms, diarylalkylamino with 14-76 carbon atoms, acyl with 2-20 carbon atoms, acyloxy with 2-20 carbon atoms, alkoxy with 1-20 carbon atoms, and alkoxy with 2-20 carbon atoms. The aromatic group may be composed of a carbonyl group, an alkoxycarbonyloxy group having 2 to 20 carbon atoms, an alkylsulfonyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms (substituted or unsubstituted), an aromatic heterocyclic group having 3 to 17 carbon atoms (substituted or unsubstituted), or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings; furthermore, if these groups have hydrogen atoms, the hydrogen atoms may also be substituted with deuterium or halogens. d and e represent substitution numbers, and are integers from 1 to 4 respectively; f represents substitution numbers, and is an integer from 1 to 2. Ar 8 Each of the following can independently represent hydrogen, deuterium, halogen, cyano, nitro, alkyl with 1 to 20 carbon atoms, aralkyl with 7 to 38 carbon atoms, alkenyl with 2 to 20 carbon atoms, alkynyl with 2 to 20 carbon atoms, dialkylamino with 2 to 40 carbon atoms, diarylamino with 12 to 44 carbon atoms, diarylalkylamino with 14 to 76 carbon atoms, acyl with 2 to 20 carbon atoms, acyloxy with 2 to 20 carbon atoms, alkoxy with 1 to 20 carbon atoms, alkoxycarbonyl with 2 to 20 carbon atoms, alkoxycarbonyloxy with 2 to 20 carbon atoms, alkylsulfonyl with 1 to 20 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group with 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic group with 3 to 17 carbon atoms, or substituted or unsubstituted linked aromatic groups formed by the linkage of 2 to 5 of these aromatic rings. The general formula (2) is further represented by any of the following general formulas (9) to (13). Here, Ar 8 d, e, and f have the same meanings as in formula (2), In the general formulas (9) to (13), Ar 6 and Ar 7 Ar is an aromatic hydrocarbon group with 6 to 10 carbon atoms, substituted or unsubstituted, an aromatic heterocyclic group with 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings. 6 and Ar 7 At least one of them contains an aromatic heterocycle with 6 to 17 carbon atoms.

2. The organic electric field light-emitting element according to claim 1, wherein, In the general formula (1), Z 1 , or Z 2 is linked to the six-membered ring comprising X by any one of them.

3. The organic electric field light-emitting element according to claim 1 or 2, wherein, In the general formula (1), Y is O or S.

4. The organic electric field light-emitting element according to claim 1, wherein, The general formula (1) is represented by any one of the following general formulas (4) to (8). Here, X, Y, Ar, Ar 1 , Ar 2 , Z 1 ~ Z 8 , a, b, and c have the same meanings as in the general formula (1).

5. The organic electric field light-emitting element according to claim 4, wherein, In the general formula (4) to general formula (8), Z is linked to the six-membered ring containing X 2 through 6. The organic electric field light-emitting element according to claim 5, wherein, In the general formula (4) to general formula (8), Ar 1 , and Ar 2 are a substituted or unsubstituted carbon number 6 to 10 aromatic hydrocarbon group, or a substituted or unsubstituted linked aromatic group of 2 to 5 linking of the aromatic rings of these.

7. The organic electric field light-emitting element according to claim 1 or 2, wherein, The dopant material is a phosphorescent dopant material or a fluorescent dopant material containing thermally activated delayed fluorescence emission.

8. A mixed composition, characterized in that, It includes compounds represented by the following general formula (1) and compounds represented by the following general formula (2). Here, ring A is the heterocyclic ring represented by equation (1a), and ring A and the adjacent rings are condensed at any position. X represents N or C-Ar', where at least one of X represents N; Y represents O, S, N-Ar 3 , or C-Ar 4 Ar 5 ; Z 1 ~Z 4 any one of Z 5 ~Z 8 each independently represents C-Ar', or N, which can be the same or different in the presence of a plurality of Ar'. Ar, Ar' and Ar 1 ~Ar 5 Each of the following groups independently represents hydrogen, deuterium, halogen, cyano, nitro, alkyl with 1-20 carbon atoms, aralkyl with 7-38 carbon atoms, alkenyl with 2-20 carbon atoms, alkynyl with 2-20 carbon atoms, dialkylamino with 2-40 carbon atoms, diarylamino with 12-44 carbon atoms, diarylalkylamino with 14-76 carbon atoms, acyl with 2-20 carbon atoms, acyloxy with 2-20 carbon atoms, alkoxy with 1-20 carbon atoms, and alkoxy with 2-20 carbon atoms. The aromatic group may be composed of a carbonyl group, an alkoxycarbonyloxy group having 2 to 20 carbon atoms, an alkylsulfonyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms (substituted or unsubstituted), an aromatic heterocyclic group having 3 to 17 carbon atoms (substituted or unsubstituted), or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings; furthermore, if these groups have hydrogen atoms, the hydrogen atoms may also be substituted with deuterium or halogens. a and b represent substitution numbers, and each independently represents an integer from 1 to 4; in addition, c represents substitution number, and represents an integer from 1 to 2. Here, ring B is the heterocyclic ring represented by equation (2a), and ring B condenses with adjacent rings at any position. Ar 6 and Ar 7 Each of the following groups independently represents hydrogen, deuterium, halogen, cyano, nitro, alkyl with 1-20 carbon atoms, aralkyl with 7-38 carbon atoms, alkenyl with 2-20 carbon atoms, alkynyl with 2-20 carbon atoms, dialkylamino with 2-40 carbon atoms, diarylamino with 12-44 carbon atoms, diarylalkylamino with 14-76 carbon atoms, acyl with 2-20 carbon atoms, acyloxy with 2-20 carbon atoms, alkoxy with 1-20 carbon atoms, and alkoxy with 2-20 carbon atoms. The aromatic group may be composed of a carbonyl group, an alkoxycarbonyloxy group having 2 to 20 carbon atoms, an alkylsulfonyl group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 30 carbon atoms (substituted or unsubstituted), an aromatic heterocyclic group having 3 to 17 carbon atoms (substituted or unsubstituted), or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings; furthermore, if these groups have hydrogen atoms, the hydrogen atoms may also be substituted with deuterium or halogens. d and e represent substitution numbers, and are integers from 1 to 4 respectively; f represents substitution numbers, and is an integer from 1 to 2. Ar 8 Each of the following can independently represent hydrogen, deuterium, halogen, cyano, nitro, alkyl with 1 to 20 carbon atoms, aralkyl with 7 to 38 carbon atoms, alkenyl with 2 to 20 carbon atoms, alkynyl with 2 to 20 carbon atoms, dialkylamino with 2 to 40 carbon atoms, diarylamino with 12 to 44 carbon atoms, diarylalkylamino with 14 to 76 carbon atoms, acyl with 2 to 20 carbon atoms, acyloxy with 2 to 20 carbon atoms, alkoxy with 1 to 20 carbon atoms, alkoxycarbonyl with 2 to 20 carbon atoms, alkoxycarbonyloxy with 2 to 20 carbon atoms, alkylsulfonyl with 1 to 20 carbon atoms, substituted or unsubstituted aromatic hydrocarbon group with 6 to 30 carbon atoms, substituted or unsubstituted aromatic heterocyclic group with 3 to 17 carbon atoms, or substituted or unsubstituted linked aromatic groups formed by the linkage of 2 to 5 of these aromatic rings. The general formula (2) is further represented by any of the following general formulas (9) to (13). Here, Ar 8 , d, e, and f have the same meaning as in equation (2). In the general formulas (9) to (13), Ar 6 and Ar 7 Ar is an aromatic hydrocarbon group with 6 to 10 carbon atoms, substituted or unsubstituted, an aromatic heterocyclic group with 3 to 17 carbon atoms, or a substituted or unsubstituted linked aromatic group consisting of 2 to 5 of these aromatic rings. 6 and Ar 7 At least one of them contains an aromatic heterocycle with 6 to 17 carbon atoms.

9. The mixed composition according to claim 8, characterized in that: The difference in temperature between the compound represented by general formula (1) and the compound represented by general formula (2) by a 50% weight reduction is within 20°C.

10. A method for manufacturing an organic electric field light-emitting element, characterized in that: The luminescent layer is made using the hybrid composition as described in claim 8 or 9.

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