Mixture of two host materials, and an organic electroluminescent device comprising the same

Abstract

The present invention relates to an organic electroluminescent device containing a mixture comprising an electron-transporting host material and a hole-transporting host material, a formulation containing the mixture of host materials, and a mixture containing the host materials. The electron-transporting host material corresponds to a compound of formula (1) in the class of compounds containing two triazine units. The hole-transporting host material corresponds to a compound of formula (2) in the class of biscarbazoles or their derivatives.

Description

Technical Field

[0001] The present invention relates to an organic electroluminescent device containing a mixture comprising an electron-transporting host material and a hole-transporting host material, a formulation comprising a mixture of host materials, and a mixture comprising host materials. The electron-transporting host material corresponds to a compound of formula (1) from a class of compounds containing two triazine units as described below. The hole-transporting host material corresponds to a compound of formula (2) from a class of biscarbazoles or derivatives thereof as described below.

[0002] The structure of organic electroluminescent devices (e.g., OLED - organic light emitting diodes or OLEC - organic light emitting electrochemical cells) in which organic semiconductors are used as functional materials has been known for a long time. The luminescent materials used here, in addition to fluorescent phosphors, are increasingly organometallic complexes that exhibit phosphorescence rather than fluorescence. For quantum mechanical reasons, using organometallic compounds as phosphorescent emitters can lead to a maximum four-fold increase in energy and power efficiency. However, generally, in the case of OLEDs, especially in the case of OLEDs that exhibit triplet emission (phosphorescence), there is still a need for improvement, especially with regard to efficiency, operating voltage, and lifetime.

[0003] The properties of organic electroluminescent devices are not always determined only by the emitter used. Here, equally particularly important are, in particular, the other materials used, such as host and matrix materials, hole blocking materials, electron transporting materials, hole transporting materials, and electron or exciton blocking materials, among which, in particular, host or matrix materials. Improvement of these materials can potentially lead to a clear improvement of the electroluminescent device.

[0004] Host materials for use in organic electronic devices are well known to those skilled in the art. The term matrix material is also frequently used in the prior art when it means a host material for a phosphorescent emitter. The use of this term is also applicable to the present invention. So far, a number of host materials for both fluorescent and phosphorescent electronic devices have been developed.

[0005] Another approach to improving the performance data of electronic devices, particularly organic electroluminescent devices, is to use a combination of two or more materials, particularly host materials or matrix materials.

[0006] US6,392,250B1 discloses the use of a mixture of an electron transport material, a hole transport material, and a fluorescent emitter in the light-emitting layer of an OLED. With the help of this mixture, it was possible to improve the lifetime of the OLED compared to the prior art.

[0007] US6,803,720B1 discloses the use of a mixture containing a phosphorescent emitter, a hole transport material, and an electron transport material in the light-emitting layer of an OLED. Here, both the hole transport material and the electron transport material are organic small molecules.

[0008] KR20100131745 describes a specifically bonded bisterazine compound and its use as a host material in an organic electroluminescent device. It also describes a device containing these bisterazine compounds in the light-emitting layer together with an indolocarbazole compound as an additional host material.

[0009] WO2012048779 is an ink for use in an organic electroluminescent device comprising a carbazole compound, an electron transport compound, a triplet emitter compound and at least one solvent, wherein the electron transport compound comprises a ketone compound or a triazine compound, which triazine compound may also be a specifically-bonded triazine compound, and the carbazole compound contains at least two carbazole groups bonded to each other via their N atoms.

[0010] US20140299192 discloses a specifically-bonded bistriazine compound and its use in an organic electroluminescent device, particularly as an electron transport material.

[0011] JP2015106658 also describes its use as a host material, particularly in combination with a dibenzofuran compound substituted at the 2- and 8-positions by 4,6-diphenyl-1,3,5-triazin-2-yl-phenyl, and a further host material in an organic electroluminescent device.

[0012] WO2015169412 describes a compound containing two triazine units that can be used as a host material in an organic electroluminescent device in combination with a further host material.

[0013] US2016329502 discloses an organic electroluminescent device containing a light-emitting layer comprising three components, namely a first host material, a compound according to the invention as a second host material, and an emitter, wherein the compound according to the invention may contain two triazine units.

[0014] US20170054087 describes a specific triazine derivative and its use as a host material in combination with other host materials in a light-emitting electronic device.

[0015] WO2017178311 describes certain dibenzofuran compounds or dibenzothiophene compounds which may have two triazine substituents, and their use in organic electroluminescent devices where these compounds can also be used as host materials. It is further described that this type of compound can be combined with additional host materials. Table 1 represents, for example, the structure of an organic light emitting diode (E11) containing two host materials in the light emitting layer, where 7,7-dimethyl-5-phenyl-2-(9-phenylcarbazol-3-yl)indenol[2,1-b]carbazole is used as the second host material.

[0016] CN108250189 describes certain dibenzofuran compounds or dibenzothiophene compounds which may have two triazine substituents, and their use as host materials in organic electroluminescent devices.

[0017] US2019013490 describes certain dibenzofuran compounds or dibenzothiophene compounds, and their use as host materials in combination with additional host materials.

[0018] WO19017730 describes certain dibenzofuran compounds or dibenzothiophene compounds, and their use as host materials.

[0019] WO19122899 describes certain bistriazine compounds, and their use as host materials in a light emitting layer in combination with a light emitting material.

[0020] However, when using these materials, or when using mixtures of materials, there is still a need for improvement, particularly with regard to the efficiency, operating voltage and / or lifetime of organic electroluminescent devices.

[0021] Accordingly, an object of the present invention is to provide a combination of host materials that is suitable for use in organic electroluminescent devices, particularly fluorescent or phosphorescent OLEDs, and that leads to good device characteristics, particularly with regard to improved lifetime, and to provide a corresponding electroluminescent device.

[0022] This object is achieved by a combination of at least one compound of formula (1) as a first host material and at least one hole-transporting compound of formula (2) as a second host material in the emission layer of an organic electroluminescent device, and it has now been found that the disadvantages from the prior art are overcome. The use of this type of material combination for the production of the emission layer in an organic electroluminescent device leads to very good characteristics of these devices, particularly with regard to lifetime, particularly with the same or improved efficiency and / or operating voltage. These advantages are also evident, in particular, in combination with a phosphor of formula (3) in a concentration of 2 to 15% by weight, particularly in the presence of the luminescent component in the emission layer.

[0023] Accordingly, the present invention provides, firstly, an organic electroluminescent device comprising an anode, a cathode, and at least one organic layer comprising at least one emission layer, wherein at least one emission layer comprises at least one compound of formula (1) as host material 1 and at least one compound of formula (2) as host material 2:

[0024] [Chemical formula]

[0025] (wherein the following apply to the symbols and subscripts used: Y is O, S, C(CH3)2, C(phenyl)2 or

[0026] [Chemical formula]

[0027] selected from, wherein * represents a C atom bonded to the remainder of formula (1), L is a divalent linker L-1 to L-26:

[0028] [Chemical formula]

[0029] [Chemical formula]

[0030]

[0031] selected from one of, wherein the linkers L-1 to L-26 may also be substituted by one or more substituents R, W is O, S or C(CH3)2, preferably O or S, a is 0 or 1, b is 0 or 1, R, each time it appears, is the same or different and is selected from the group consisting of CN, a linear alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms, or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms, or an aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms, Ar1, each time it appears, is independently of each other in each case an aryl or heteroaryl group having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R, K and M, in each case independently of one another, are aromatic ring systems having from 6 to 40 aromatic ring atoms, which, when x and y represent 0 and x1 and y1 represent 0, are unsubstituted or partially or fully deuterated or substituted by R * monosubstituted by or alternatively K and M, in each case independently of one another, when the values of x, x1, y and / or y1 represent 1, together with X or X 1 form a heteroaromatic ring system having from 14 to 40 ring atoms, x and x1, in each case independently of one another, each time they occur, are 0 or 1, y and y1, in each case independently of one another, each time they occur, are 0 or 1, X and X 1 are, in each case independently of one another, each time they occur, a bond or C(R#)2, R 0 is, each time it occurs, independently of one another, an unsubstituted or partially or fully deuterated aromatic ring system having from 6 to 18 C atoms, R * is dibenzofuranyl or dibenzothiophenyl, R# is, each time it occurs, independently of one another, a linear or branched alkyl group having from 1 to 4 C atoms, c, d, e and f are, independently of one another, 0 or 1) relates to an organic electroluminescent device comprising.

[0032] The present invention further encompasses a method for manufacturing an organic electroluminescent device, and a mixture, a specific material combination, and a formulation comprising at least one compound of formula (1) and at least one compound of formula (2). The present invention similarly relates to corresponding preferred embodiments as described below. By specific selection of the compounds of formula (1) and the compounds of formula (2), surprisingly advantageous effects are achieved.

[0033] The organic electroluminescent device according to the present invention is, for example, an organic light-emitting transistor (OLET), an organic field quenching device (OFQD), an organic light-emitting electrochemical cell (OLEC, LEC, LEEC), an organic laser diode (O-laser), or an organic light-emitting diode (OLED). The organic electroluminescent device according to the present invention is particularly an organic light-emitting diode or an organic light-emitting electrochemical cell. The device according to the present invention is particularly preferably an OLED.

[0034] The organic layer of the device according to the present invention, which includes a light-emitting layer containing a material combination of at least one compound of formula (1) and at least one compound of formula (2) as described above or below, preferably includes, in addition to this light-emitting layer (EML), a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), an electron injection layer (EIL), and / or a hole blocking layer (HBL). The device according to the present invention may also include a plurality of layers from this group selected from EML, HIL, HTL, ETL, EIL, and HBL.

[0035] However, the device may also contain an inorganic material or include a layer constructed entirely of inorganic materials.

[0036] The light-emitting layer containing at least one compound of formula (1) and at least one compound of formula (2) is preferably a phosphorescent layer characterized by containing at least one phosphorescent emitter in addition to the host material combination of the compounds of formula (1) and formula (2) as described above. Suitable selection of emitters and preferred emitters are described below.

[0037] An aryl group in the sense of the present invention contains 6 to 40 aromatic ring atoms, preferably C atoms. A heteroaryl group in the sense of the present invention contains 5 to 40 aromatic ring atoms, and the ring atoms include C atoms and at least 1 heteroatom, provided that the total of C atoms and heteroatoms is at least 5. The heteroatom is preferably selected from N, O and / or S. The aryl group or heteroaryl group here means any of a simple aromatic ring derived from benzene, i.e., phenyl, or a simple heteroaromatic ring derived from, for example, pyridine, pyrimidine or thiophene, or a condensed aryl or heteroaryl group derived from, for example, naphthalene, anthracene, phenanthrene, quinoline or isoquinoline. Therefore, an aryl group having 6 to 18 carbon atoms is preferably phenyl, naphthyl, phenanthryl or triphenylenyl, and there is no restriction on the bonding of the aryl group as a substituent. An aryl or heteroaryl group in the sense of the present invention may have one or more radicals R, and the substituent R is described below.

[0038] An aromatic ring system in the sense of the present invention contains 6 to 40 C atoms in the ring system. The aromatic ring system also includes an aryl group as described above.

[0039] An aromatic ring system having 6 to 18 C atoms is preferably selected from phenyl, biphenyl, naphthyl, phenanthryl and triphenylenyl.

[0040] A heteroaromatic ring system in the sense of the present invention contains 5 to 40 ring atoms and at least 1 heteroatom. Preferred heteroaromatic ring systems have 10 to 40 ring atoms and at least 1 heteroatom. The heteroaromatic ring system also includes a heteroaryl group as described above. The heteroatoms of the heteroaromatic ring system are preferably selected from N, O and / or S.

[0041] For the purposes of the present invention, an aromatic or heteroaromatic ring system does not necessarily contain only aryl or heteroaryl groups, and moreover, some aryl or heteroaryl groups may be interrupted by non-aromatic units (preferably less than 10% of atoms other than H), for example, C, N or O atoms or carbonyl groups. Thus, for example, systems such as 9,9'-spirobifluorene, 9,9-diarylfluorene, triarylamine, diaryl ether, stilbene, etc. are intended to be understood as aromatic or heteroaromatic ring systems in the context of the present invention, and similarly, systems in which two or more aryl groups are interrupted by, for example, linear or cyclic alkyl groups or by silyl groups. Systems in which two or more aryl or heteroaryl groups are directly bonded to each other, for example, biphenyl, terphenyl, quarterphenyl or bipyridine, are likewise included in the definition of aromatic or heteroaromatic ring systems.

[0042] An aromatic or heteroaromatic ring system having 5 to 40 ring atoms, which may be linked through any desired position on the aromatic or heteroaromatic ring, includes, for example, benzene, naphthalene, anthracene, benzoanthracene, phenanthrene, benzophenanthrene, pyrene, chrysene, perylene, fluoranthene, benzofluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, biphenylene, terphenyl, terphenylene, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indenofluorene, cis- or trans-monobenzoindenofluorene, cis- or trans-dibenzoindenofluorene, torquene, isotorquene, spirotorquene, spiroisotorquene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, indolocarbazole, indenocarbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthoimidazole, phenanthroimidazole, pyridoimidazole, pyrazinoimidazole, quinoxalineimidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, 1,5-diazaanthracene, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazaperylene, pyrazine, phenazine, phenoxazine, phenothiazine, fluorubine, naphthyridine, azacarbazole, benzocarbazole, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,It is understood to mean a group derived from 5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine and benzothiadiazole.,

[0043] The abbreviation Ar1, each time it appears, independently of one another in each case, is an aryl or heteroaryl group having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R, and the radical R has the meaning as described above or below.,

[0044] The cyclic alkyl, alkoxy or thioalkyl group in the sense of the present invention is understood to mean a monocyclic, bicyclic or polycyclic group.,

[0045] For the purposes of the present invention, linear, branched or cyclic C1-C 20The alkyl group is understood to mean, for example, radicals such as methyl, ethyl, n-propyl, i-propyl, cyclopropyl, n-butyl, i-butyl, s-butyl, t-butyl, cyclobutyl, 2-methylbutyl, n-pentyl, s-pentyl, t-pentyl, 2-pentyl, neopentyl, cyclopentyl, n-hexyl, s-hexyl, t-hexyl, 2-hexyl, 3-hexyl, neohexyl, cyclohexyl, 1-methylcyclopentyl, 2-methylpentyl, n-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, cycloheptyl, 1-methylcyclohexyl, n-octyl, 2-ethylhexyl, cyclooctyl, 1-bicyclo[2,2,2]octyl, 2-bicyclo[2,2,2]octyl, 2-(2,6-dimethyl)octyl, 3-(3,7-dimethyl)octyl, adamantyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, 1,1-dimethyl-n-hex-1-yl, 1,1-dimethyl-n-hept-1-yl, 1,1-dimethyl-n-oct-1-yl, 1,1-dimethyl-n-dec-1-yl, 1,1-dimethyl-n-dodec-1-yl, 1,1-dimethyl-n-tetradec-1-yl, 1,1-dimethyl-n-hexadec-1-yl, 1,1-dimethyl-n-octadec-1-yl, 1,1-diethyl-n-hex-1-yl, 1,1-diethyl-n-hept-1-yl, 1,1-diethyl-n-oct-1-yl, 1,1-diethyl-n-dec-1-yl, 1,1-diethyl-n-dodec-1-yl, 1,1-diethyl-n-tetradec-1-yl, 1,1-diethyl-n-hexadec-1-yl, 1,1-diethyl-n-octadec-1-yl, 1-(n-propyl)cyclohex-1-yl, 1-(n-butyl)cyclohex-1-yl, 1-(n-hexyl)cyclohex-1-yl, 1-(n-octyl)cyclohex-1-yl and 1-(n-decyl)cyclohex-1-yl.

[0046] Linear or branched C1-C 20An alkoxy group is understood to mean, for example, methoxy, trifluoromethoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy or 2-methylbutoxy.

[0047] A linear C1-C 20 A thioalkyl group is understood to mean, for example, an S-alkyl group, such as thiomethyl, 1-thioethyl, 1-thio-i-propyl, 1-thio-n-propyl, 1-thio-i-butyl, 1-thio-n-butyl or 1-thio-t-butyl.

[0048] An aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms represents O-aryl or O-heteroaryl, meaning that the aryl or heteroaryl group is bonded via an oxygen atom, and the aryl or heteroaryl group has the meaning as described above.

[0049] An aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms means that the alkyl group as described above is substituted by an aryl group or a heteroaryl group, and the aryl or heteroaryl group has the meaning as described above.

[0050] The phosphorescent emitter in the sense of the present invention is a compound that emits light from an excited state with a higher spin multiplicity, i.e., an excited state with a spin state exceeding 1, particularly from an excited triplet state. For the purposes of this application, it is intended that all luminescent complexes having a transition metal or a lanthanide are considered to be phosphorescent emitters. A more precise definition is given below.

[0051] When a host material of a light-emitting layer containing at least one compound of formula (1) as described previously or as described preferably below and at least one compound of formula (2) as described previously or as described preferably below is used for a phosphorescent emitter, it is preferred that its triplet energy is not significantly lower than the triplet energy of the phosphorescent emitter. Regarding the triplet level, preferably the following applies: T1 (emitter) - T1 (matrix) is 0.2 eV or less, particularly preferably 0.15 eV or less, and very particularly preferably 0.1 eV or less, where T1 (matrix) is the triplet level of the matrix material in the light-emitting layer, and this condition applies to each of the two matrix materials, and T1 (emitter) is the triplet level of the phosphorescent emitter. When the light-emitting layer contains more than two matrix materials, the aforementioned relationship preferably also applies to each of the additional matrix materials.

[0052] Host material 1 present in the device according to the present invention and its preferred embodiments are described below. The preferred embodiments of host material 1 of formula (1) also apply to the mixtures and / or formulations according to the present invention.

[0053] In the compound of formula (1), Y is O, S, C(CH3)2, C(phenyl)2 or

[0054]

Chemical formula

[0055] selected from, and in the formula, * represents the C atom bonded to the remaining part of formula (1).

[0056] Y is preferably selected from O, S and C(CH3)2.

[0057] Y is particularly preferably selected from O and S.

[0058] In a very particularly preferred embodiment of the host material of formula (1), Y represents O.

[0059] Accordingly, the present invention further relates to an organic electroluminescent device as described above, wherein Y in the host material 1 represents O.

[0060] In the compound of formula (1), a represents 0 or 1, preferably 0.

[0061] In the compound of formula (1), b represents 0 or 1, preferably 0.

[0062] In the compound of formula (1), R, each time it appears, is the same or different and is selected from the group consisting of CN, a linear alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms, or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms, or an aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms. The substituent R preferably, each time it appears, independently of one another, represents CN or an aryl group having 6 to 40 C atoms. R is particularly preferably phenyl, each time it appears, independently of one another.

[0063] In the compound of formula (1) as described previously or as described as preferred, Ar1 preferably represents, each time it occurs, independently of one another, an aryl group having 6 to 40 aromatic ring atoms, or represents dibenzofuranyl, or represents dibenzothiophenyl. In the compound of formula (1) as described previously or as described as preferred, Ar1, in each case, independently of one another, particularly preferably represents phenyl, triphenylenyl, biphenyl, fluorenyl, naphthyl or dibenzofuranyl, and the bond to the remainder of formula (1) can occur via any desired position of the aryl group, dibenzofuranyl or dibenzothiophenyl. For example, dibenzofuran is preferably bonded to the remainder of formula (1) via the 1, 3 or 7 position. Fluorene is preferably bonded to the remainder of formula (1) via, for example, the 8 position. A preferred biphenyl is 1,3-biphenyl.

[0064] Particularly preferably, at least one Ar1 represents phenyl, and the other aromatic substituent Ar1 represents an aryl group having 6 to 40 aromatic ring atoms, or represents dibenzofuranyl, or represents dibenzothiophenyl. Very particularly preferably, both groups Ar1 are the same. Very particularly preferably, both groups Ar1 represent phenyl. Preferably, both groups Ar1 represent dibenzofuranyl in which the bond to the triazine is independent in each case.

[0065] In the compound of formula (1), L is selected from the group of linkers L-1 to L-26, and the linkers L-1 to L-26 may also be substituted by one or more substituents R. The linkers L-1 to L-26 are preferably unsubstituted or have one substituent R. The linkers L-1 to L-26 are particularly preferably unsubstituted.

[0066] The substituents R in linkers L-1 to L-26 are, each time they occur, the same or different and are selected from the group consisting of CN, a linear alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms, or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms, or an aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms. In linkers L-1 to L-26, the substituents R preferably, each time they occur, independently of one another, represent CN or an aryl group having 6 to 40 C atoms. In linkers L-1 to L-26, the substituents R particularly preferably, each time they occur, independently of one another, represent CN or phenyl.

[0067] The host material of formula (1) having linkers L-1 to L-26 as described above or as described as preferred is preferably combined with a host material of formula (2) (wherein at least one of the values x, x1, y or y1 represents 1), which is preferably represented by a compound of formula (2b) or (2c) as described below. The host material of formula (1) having linkers L-1 to L-26 as described above or as described as preferred is preferably combined with a host material of formula (2) (wherein exactly one of the values x, x1, y or y1 represents 1), which is preferably represented by a compound of formula (2b) as described below.

[0068] A host material of formula (1) having linkers L-14 to L-23 as described above (wherein W represents O, S or C(CH3)2, and W is preferably O or S) is preferably combined with a host material of formula (2) (wherein at least one of the values x, x1, y or y1 represents 1), which is preferably represented by a compound of formula (2b) or (2c) as described below. A host material of formula (1) having linkers L-14 to L-23 as described above or as described as preferred is preferably combined with a host material of formula (2) (wherein exactly one of the values x, x1, y or y1 represents 1), which is preferably represented by a compound of formula (2b) as described below.

[0069] In the compound of formula (1) as described above or as described as preferred, L is preferably selected from linkers L-1 to L-13 and L-24 to L-26 as described above.

[0070] A host material of formula (1) having linkers L-1 to L-13 and L-24 to L-26 is preferably combined with a host material of formula (2) (wherein x and x1 each independently represent 0 or 1 each time they appear, and y and y1 each independently represent 0 or 1 each time they appear), which is preferably represented by a compound of formula (2a), (2b) or (2c) as described below.

[0071] It is more preferred that the linker L in the host material of formula (1) is selected from linkers L-2, L-3, L-4, L-24, L-25 and L-26.

[0072] In the compound of formula (1) as described above or as described as preferred, L is alternatively preferably selected from linkers L-2, L-3, L-4, L-16, L-18, L-20, L-24, L-25 and L-26 as described above, wherein W represents O, S or C(CH3)2, and W is preferably O or S.

[0073] Accordingly, the present invention further relates to an organic electroluminescent device as described above or as described as preferable, wherein the linker L in the host material 1 is selected from linkers L-1 to L-13 and L-24 to L-26.

[0074] Accordingly, the present invention further relates to an organic electroluminescent device as described above or as described as preferable, wherein the linker L in the host material 1 is selected from linkers L-2, L-3, L-4, L-16, L-18, L-20, L-24, L-25 and L-26, and W represents O, S or C(CH3)2. W is preferably O or S.

[0075] Examples of suitable host materials of formula (1) selected according to the present invention and preferably used in combination with at least one compound of formula (2) in the electroluminescent device according to the present invention are structures shown in Table 1 below.

[0076] [Table 1-1]

[0077] [Table 1-2]

[0078] [Table 1-3]

[0079] [Table 1-4]

[0080] [Table 1-5]

[0081]

Table 1-6

[0082]

Table 1-7

[0083] Preferably, in the electroluminescent device according to the present invention, particularly preferred compounds of formula (1) used in combination with at least one compound of formula (2) are Compounds 1 to 11 and 29 to 44:

[0084]

Chemical formula

[0085]

Chemical formula

[0086]

Chemical formula

[0087]

Chemical formula

[0088] The preparation of the compounds of formula (1) or the preferred compounds from Table 1, as well as Compounds 1-11 and 29-44, is known to those skilled in the art. The compounds can be prepared by synthetic processes known to those skilled in the art, such as halogenation, preferably bromination, followed by an organometallic coupling reaction, such as a Suzuki coupling, a Heck coupling or a Hartwig-Buchwald coupling. The preparation of the compounds of formula (1) or the preferred compounds from Table 1, as well as Compounds 1-11 and 29-44, can be derived in particular from WO2017178311, in particular from the synthesis examples on pages 46 and 81-106.

[0089] The preparation of the compounds of formula (1) can be carried out according to Scheme 1 below, where Y, R, a, b, Ar1 and L have one of the meanings indicated above or indicated as preferred.

[0090]

Chemical formula

[0091] The host material 2 present in the device according to the invention and its preferred embodiments are described below. The preferred embodiments of the host material 1 of formula (1) also apply to the mixtures and / or formulations according to the invention.

[0092] The host material 2 is at least one compound of formula (2):

[0093]

Chemical formula

[0094] (In which the following apply to the symbols and subscripts used: K and M are, in each case, independently of one another, an aromatic ring system having 6 to 40 aromatic ring atoms, which is unsubstituted, or partially or fully deuterated, or mono-substituted by R * or In each case, K and M are independently of each other, when the values of x, x1, y and / or y1 represent 1, X or X 1 together form a heteroaromatic ring system having 14 to 40 ring atoms, in each case, each time they occur, x and x1 are independently 0 or 1, in each case, each time they occur, y and y1 are independently 0 or 1, X and X 1 in each case, each time they occur, are independently of each other a bond or C(R#)2, R 0 in each case, each time it occurs, is independently of the others an unsubstituted or partially or fully deuterated aromatic ring system having 6 to 18 C atoms, in each case, each time it occurs, R# is independently of the others a straight-chain or branched alkyl group having 1 to 4 C atoms, c, d, e and f are independently of each other 0 or 1) is as follows.

[0095] In an embodiment of the invention, a compound of formula (2) as described above is selected for a device according to the invention, and this compound is used in the light-emitting layer together with a compound of formula (1) as described above or described as preferred, or together with a compound from Table 1, or compounds 1 to 11 and 29 to 44.

[0096] In a preferred embodiment of a device according to the invention, a compound of formula (2) in which x, y, x1 and y1 represent 0 is used as host material 2. A compound of formula (2) in which x, x1, y and y1 represent 0 has the following formula (2a):

[0097]

Chemical formula

[0098] (wherein R 0 , c, d, e and f have the meanings shown above or shown below, In each case, K and M independently of one another represent an aromatic ring system having 6 to 40 aromatic ring atoms, which is unsubstituted, or partially or fully deuterated, or mono-substituted by R * (represented by) can be represented by.

[0099] In the preferred compounds of formula (2a), the sum of the subscripts c + d + e + f is preferably 0 or 1, and R 0 has the meanings indicated as preferred above or below.

[0100] In the compounds of formula (2) or (2a), R 0 is preferably, each time it occurs and independently of one another, an unsubstituted aromatic ring system having 6 to 18 C atoms. R 0 is preferably, each time it occurs and independently of one another, phenyl, 1,3-biphenyl, 1,4-biphenyl, naphthyl or triphenylenyl. R 0 is particularly preferably, each time it occurs and independently of one another, phenyl.

[0101] In the compounds of formula (2) or (2a), the subscripts c, d, e and f are particularly preferably 0.

[0102] In the compounds of formula (2) or (2a), K and M are, as described above, preferably, each time they occur and independently of one another, an unsubstituted or partially deuterated or mono-substituted by R * aromatic ring system having 6 to 40 aromatic ring atoms. K and M in the compounds of formula (2) or (2a) are particularly preferably, each time they occur and independently of one another, phenyl, dibenzofuran-substituted phenyl, dibenzothiophene-substituted phenyl, deuterated phenyl, 1,3-biphenyl, 1,4-biphenyl, terphenyl, partially deuterated terphenyl, quaterphenyl, naphthyl, fluorenyl, 9,9-diphenylfluorenyl, bisspirofluorenyl or triphenylenyl.

[0103] Accordingly, the present invention further relates to an organic electroluminescent device as described above or described as preferred, wherein at least one compound of formula (2) corresponds to a compound of formula (2a) or a preferred embodiment of the compound of formula (2a).

[0104] In a preferred embodiment of the device according to the invention, a compound of formula (2) (wherein x1 and y1 represent 0, x and y represent 0 or 1, and the sum of x and y represents 1 or 2) is used as host material 2. The compound of formula (2) (wherein x1 and y1 represent 0, x and y represent 0 or 1, and the sum of x and y represents 1 or 2) has the following formula (2b):

[0105]

Chemical formula

[0106] (wherein X, x, y, R 0 , c, d, e and f have the meanings shown above or shown below, M is an aromatic ring system having 6 to 40 aromatic ring atoms, which is unsubstituted, or partially or fully deuterated, or monosubstituted by R * , K forms a heteroaromatic ring system having 14 to 40 ring atoms together with X when the value of x or y is 1, or when the values of both x and y are 1) can be represented by.

[0107] In a preferred compound of formula (2b), the sum of the subscripts c + d + e + f is preferably 0 or 1, and R 0 has the meanings shown above or shown as preferred.

[0108] In the compound of formula (2) or (2b), the subscripts c, d, e and f are particularly preferably 0.

[0109] In the compound of formula (2) or (2b), when the sum of x + y represents 1 or 2, K preferably forms a heteroaromatic ring system. X in the compound of formula (2) or (2b) is preferably a direct bond or C(CH3)2.

[0110] Preferred compounds of formula (2) or (2b) are of formula (2b-1) to (2b-6):

[0111]

Chemical formula

[0112] (wherein M, R 0 , c, d, e and f have the meanings shown previously or indicated as preferred) can be represented by.

[0113] In the compounds of formula (2), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) or (2b-6), M is preferably, as described previously, unsubstituted, or partially deuterated, or monosubstituted by R * and is an aromatic ring system having 6 to 40 aromatic ring atoms. M in the compounds of formula (2), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) or (2b-6) is particularly preferably phenyl, dibenzofuran-substituted phenyl, dibenzothiophene-substituted phenyl, deuterated phenyl, 1,3-biphenyl, 1,4-biphenyl, terphenyl, partially deuterated terphenyl, quaterphenyl, naphthyl, fluorenyl, 9,9-diphenylfluorenyl, bisspirofluorenyl or triphenylenyl.

[0114] In the compounds of formula (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) or (2b-6), c, d, e and f are preferably 0.

[0115] Accordingly, the present invention further relates to an organic electroluminescent device as described above or as described as preferred, wherein at least one compound of formula (2) corresponds to a compound of formula (2b), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) or (2b-6) or a preferred embodiment of these compounds.

[0116] In a preferred embodiment of the device according to the present invention, a compound of formula (2) (wherein c and f represent 0 or 1, d and e represent 0, and x, x1, y and y1 each independently represent 0 or 1 each time they appear, provided that the sum of x and y represents at least 1 and the sum of x1 and y1 represents at least 1) is used as host material 2. Such a compound of formula (2) as described above is preferably of the following formula (2c):

[0117]

Chemical formula

[0118] (wherein X and X 1 have the meanings shown above or below, K and M each independently form, in each case, a heteroaromatic ring system having 14 to 40 ring atoms together with X or X 1 , x, x1, y and / or y1 represent 0 or 1, the sum of x and y represents at least 1, and the sum of x1 and y1 represents at least 1) can be represented by.

[0119] In preferred compounds of formula (2c), the sum of x and y is 1 or 2, and the sum of x1 and y1 is 1. In particularly preferred compounds of formula (2c), the sum of x and y is 1, and the sum of x1 and y1 is 1.

[0120] Accordingly, K and M in the compound of formula (2) or (2c) preferably form a heteroaromatic ring system. X and X in the compound of formula (2) or (2c) 1 are preferably a direct bond or C(CH3)2.

[0121] Preferred compounds of formula (2) or (2c) are those of formulae (2c-1) to (2c-8):

[0122] [Chemical formula]

[0123] [Chemical formula]

[0124] which can be represented by.

[0125] Preferred compounds of formula (2c) are also compounds 46, 47, 48, 49 and 50 as described below.

[0126] Accordingly, the present invention further relates to an organic electroluminescent device as described above or as described as preferred, wherein at least one compound of formula (2) corresponds to a compound of formula (2c), (2c-1), (2c-2), (2c-3), (2c-4), (2c-5), (2c-6), (2c-7) or (2c-8).

[0127] In a preferred embodiment of the compound of formula (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) or (2b-6), carbazole and crosslinked carbazole are linked to each other at the 3-position in each case.

[0128] In a preferred embodiment of the compound of formula (2c), two crosslinked carbazoles are linked to each other at the 3-position in each case.

[0129] Examples of suitable host materials of formulas (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) and (2c) that are selected according to the present invention and preferably used in combination with at least one compound of formula (1) in an electroluminescent device according to the present invention are the structures shown in Table 2 below.

[0130]

Table 2-1

[0131]

Table 2-2

[0132]

Table 2-3

[0133]

Table 2-4

[0134]

Table 2-5

[0135]

Table 2-6

[0136]

Table 2-7

[0137]

Table 2-8

[0138] Preferably, in the electroluminescent device according to the present invention, particularly preferred compounds of formula (2) used in combination with at least one compound of formula (1) are compounds 12 to 27 and 45 to 52:

[0139]

Chem.

[0140]

Chem.

[0141]

Chem.

[0142] The preparation of the compounds of formula (2) or the preferred compounds of formula (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) and (2c), as well as the compounds from Table 2 and compounds 12 to 27 and 45 to 52, are known to those skilled in the art. The compounds can be prepared by synthetic processes known to those skilled in the art, such as halogenation, preferably bromination, followed by an organometallic coupling reaction, such as a Suzuki coupling, a Heck coupling or a Hartwig-Buchwald coupling. Some of the compounds of formula (2) are commercially available.

[0143] The host materials of the aforementioned formula (1) and their embodiments described as preferred, or the compounds from Table 1 and Compounds 1 to 11 and 29 to 44 can be combined, if necessary, with the host materials of formula (2), (2a), (2b), (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5), (2c), (2c-1), (2c-2), (2c-3), (2c-4), (2c-5), (2c-6), (2c-7) and (2c-8), and their embodiments described as preferred, or the compounds from Table 2 or Compounds 12 to 27 and 45 to 52.

[0144] As described above, the aforementioned specific combination of the host material of formula (1) and the host material of formula (2) is preferred. The preferred combinations of host materials are also described below.

[0145] Similarly, the present invention relates to at least one compound of formula (1) and at least one compound of formula (2):

[0146]

Chemical formula

[0147] (In the formula, the following applies to the symbols and subscripts used: Y is O, S, C(CH3)2, C(phenyl)2 or

[0148]

Chemical formula

[0149] selected from, where * represents the C atom bonded to the remaining part of formula (1), L is a divalent linker L-1 to L-26:

[0150]

Chemical formula

[0151]

Chem.

[0152]

Chem.

[0153] selected from one of them, wherein the linkers L-1 to L-26 may also be substituted by one or more substituents R, W is O, S or C(CH3)2, preferably O or S, a is 0 or 1, b is 0 or 1, R is, each time it appears, the same or different and is selected from the group consisting of CN, a linear alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms, or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms, or an aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms, Ar1 is, each time it appears, independently of each other in each case, an aryl or heteroaryl group having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R, K, M are, in each case, independently of each other, an aromatic ring system having 6 to 40 aromatic ring atoms, which is unsubstituted, or partially or fully deuterated, or substituted by R when x and y are 0 and x1 and y1 are 0, or * monosubstituted by, or K, M are, in each case, independently of each other, X or X when the values of x, x1, y and / or y1 are 1, 1together form a heteroaromatic ring system having 14 to 40 ring atoms, x and x1 are each, in each occurrence, independently 0 or 1, y and y1 are each, in each occurrence, independently 0 or 1, X and X 1 are each, in each occurrence, independently of one another, a bond or C(R#)2, R 0 is, in each occurrence, independently of one another, an unsubstituted or partially or fully deuterated aromatic ring system having 6 to 18 C atoms, R * is dibenzofuranyl or dibenzothiophenyl, R# is, in each occurrence, independently of one another, a linear or branched alkyl group having 1 to 4 C atoms, c, d, e and f are independently of one another 0 or 1) relates further to a mixture comprising.

[0154] Statements regarding the host materials of formula (1) and (2), and their preferred embodiments and their combinations, also apply correspondingly to the mixtures according to the invention.

[0155] Particularly preferred mixtures of the host material of formula (1) and the host material of formula (2) for the devices according to the invention are obtained by combining compounds 1 to 11 and 29 to 44 with the compounds from Table 2.

[0156] Very particularly preferred mixtures of the host material of formula (1) and the host material of formula (2) for the devices according to the invention are obtained by combining compounds 1 to 11 and 29 to 44 with compounds 12 to 27 and 45 to 52, as shown in Table 3 below.

[0157]

Table 3-1

[0158]

Table 3-2

[0159]

Table 3-3

[0160]

Table 3-4

[0161]

Table 3-5

[0162]

Table 3-6

[0163]

Table 3-7

[0164] In the mixture according to the present invention or in the light-emitting layer of the device according to the present invention, the concentration of the electron-transporting host material of formula (1) as described above or described as preferred is in the range of 5% to 90% by weight, preferably in the range of 10% to 85% by weight, more preferably in the range of 20% to 85% by weight, even more preferably in the range of 30% to 80% by weight, very particularly preferably in the range of 20% to 60% by weight, and most preferably in the range of 30% to 50% by weight, based on the total mixture or based on the total composition of the light-emitting layer.

[0165] In the mixture according to the present invention or in the light-emitting layer of the device according to the present invention, the concentration of the hole-transporting host material of formula (2) as described above or described as preferred is in the range of 10% to 95% by weight, preferably in the range of 15% to 90% by weight, more preferably in the range of 15% to 80% by weight, even more preferably in the range of 20% to 70% by weight, very particularly preferably in the range of 40% to 80% by weight, and most preferably in the range of 50% to 70% by weight, based on the total mixture or based on the total composition of the light-emitting layer.

[0166] The present invention also relates to a mixture comprising at least a phosphorescent emitter in addition to the host materials 1 and 2 as described above or described as preferred, in particular mixtures M1 to M648.

[0167] The present invention also relates to an organic electroluminescent device as described above or described as preferred, wherein the light-emitting layer comprises at least a phosphorescent emitter in addition to the host materials 1 and 2 as described above or described as preferred, in particular material combinations M1 to M648.

[0168] The term phosphorescent emitter typically encompasses compounds in which light is emitted by spin-forbidden transitions from excited states having a higher spin multiplicity, i.e., a spin state greater than 1, for example, from a triplet state or a state having an even higher spin quantum number, such as a quintet state. This is preferably understood to mean a transition from a triplet state.

[0169] Suitable phosphorescent emitters (i.e., triplet emitters) are compounds that, when suitably excited, preferably emit light in the visible region and further contain at least one atom having an atomic number greater than 20, preferably greater than 38 and less than 84, particularly preferably greater than 56 and less than 80, especially a metal having this atomic number. The phosphorescent emitter used is preferably a compound containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold or europium, particularly a compound containing iridium or platinum. For the purposes of the present invention, all luminescent compounds containing the aforementioned metals are considered to be phosphorescent emitters.

[0170] Generally, all phosphorescent complexes as used in phosphorescent OLEDs according to the prior art and known to those skilled in the art in the field of organic electroluminescent devices are suitable.

[0171] Examples of the emitters described above are disclosed in applications WO2016 / 015815, WO00 / 70655, WO2001 / 41512, WO2002 / 02714, WO2002 / 15645, EP1191613, EP1191612, EP1191614, WO05 / 033244, WO05 / 019373, US2005 / 0258742, WO2009 / 146770, WO2010 / 015307, WO2010 / 031485, WO2010 / 054731, WO2010 / 054728, WO2010 / 086089, WO2010 / 099852, WO2010 / 102709, WO2011 / 032626, WO2011 / 066898, WO2011 / 157339, WO2012 / 007086, WO2014 / 008982, WO2014 / 023377, WO2014 / 094961, WO2014 / 094960, WO2015 / 036074, WO2015 / 104045, WO2015 / 117718, WO2016 / 015815, WO2016 / 124304, WO2017 / 032439, WO2015 / 036074, WO2015 / 117718 and WO2016 / 015815.

[0172] A preferred phosphorescent emitter according to the present invention has the formula (3):

[0173] [Chemical Formula]

[0174] (wherein the symbols and subscripts for this formula (3) have the following meanings: n + m is 3, n is 1 or 2, m is 2 or 1, X is N or CR, R is H, D, or a branched or linear alkyl group having 1 to 10 C atoms, or a partially or fully deuterated branched or linear alkyl group having 1 to 10 C atoms, or a cycloalkyl group having 4 to 7 C atoms which may be partially or fully substituted by deuterium) and conforms to.

[0175] Accordingly, the present invention further relates to an organic electroluminescent device as described above or as described as preferred, wherein the light-emitting layer contains, in addition to host materials 1 and 2, at least one phosphorescent emitter conforming to formula (3).

[0176] In the emitter of formula (3), n is preferably 1 and m is preferably 2.

[0177] In the emitter of formula (3), preferably, one X is selected from N and the other X represents CR.

[0178] In the emitter of formula (3), at least one R is preferably other than H. In the emitter of formula (3), preferably, two Rs are other than H and have one of the meanings shown above for the emitter of formula (3) in other respects.

[0179] Preferred examples of the phosphorescent phosphor are shown in Table 4 below.

[0180]

Table 4-1

[0181]

Table 4-2

[0182]

Table 4-3

[0183]

Table 4-4

[0184]

Table 4-5

[0185]

Table 4-6

[0186]

Table 4-7

[0187]

Table 4-8

[0188]

Table 4-9

[0189]

Table 4-10

[0190]

Table 4-11

[0191]

Table 4-12

[0192]

Table 4-13

[0193]

Table 4-14

[0194]

Table 4-15

[0195]

Table 4-16

[0196]

Table 4-17

[0197]

Table 4-18

[0198]

Table 4-19

[0199] Preferred examples of the phosphorescent multi-pin light-emitting device are shown in Table 5 below.

[0200]

Table 5-1

[0201]

Table 5-2

[0202]

Table 5-3

[0203]

Table 5-4

[0204] In the mixture according to the present invention, or in the light-emitting layer of the device according to the present invention, each of the mixtures M1, M2, M3, M4, M5, M6, M7, M8, M9, M10, M11, M12, M13, M14, M15, M16, M17, M18, M19, M20, M21, M22, M23, M24, M25, M26, M27, M28, M29, M30, M31, M32, M33, M34, M35, M36, M37, M38, M39, M40, M41, M42, M43, M44, M45, M46, M47, M48, M49, M50, M51, M52, M53, M54, M55, M56, M57, M58, M59, M60, M61, M62, M63, M64, M65, M66, M67, M68, M69, M70, M71, M72, M73, M74, M75, M76, M77, M78, M79, M80, M81, M82, M83, M84, M85, M86, M87, M88, M89, M90, M91, M92, M93, M94, M95, M96, M97, M98, M99, M100, M101, M102, M103, M104, M105, M106, M107, M108, M109, M110, M111, M112, M113, M114, M115, M116, M117, M118, M119, M120, M121, M122, M123, M124, M125, M126, M127, M128, M129, M130, M131, M132, M133, M134, M135, M136, M137, M138, M139, M140, M141, M142, M143, M144, M145, M146, M147, M148, M149, M150, M151, M152, M153, M154, M155, M156, M157, M158, M159, M160, M161, M162, M163, M164, M165, M166, M167, M168, M169, M170, M171, M172, M173, M174, M175, M176, M177, M178, M179, M180, M181, M182, M183, M184, M185, M186, M187, M188, M189, M190, M191, M192, M193, M194, M195, M196, M197, M198, M199, M200, M201, M202, M203, M204, M205, M206, M207, M208, M209, M210, M211, M212, M213, M214M215, M216, M217, M218, M219, M220, M221, M222, M223, M224, M225, M226, M227, M228, M229, M230, M231, M232, M233, M234, M235, M236, M237, M238, M239, M240, M241, M242, M243, M244, M245, M246, M247, M248, M249, M250, M251, M252, M253, M254, M255, M256, M257, M258, M259, M260, M261, M262, M263, M264, M265, M266, M267, M268, M269, M270, M271, M272, M273, M274, M275, M276, M277, M278, M279, M280, M281, M282, M283, M284, M285, M286, M287, M288, M289, M290, M291, M292, M293, M294, M295, M296, M297, M298, M299, M300, M301, M302, M303, M304, M305, M306, M307, M308, M309, M310, M311, M312, M313, M314, M315, M316, M317, M318, M319, M320, M321, M322, M323, M324, M325, M326, M327, M328, M329, M330, M331, M332, M333, M334, M335, M336, M337, M338, M339, M340, M341, M342, M343, M344, M345, M346, M347, M348, M349, M350, M351, M352, M353, M354, M355, M356, M357, M358, M359, M360, M361, M362, M363, M364, M365, M366, M367, M368, M369, M370, M371, M372, M373, M374, M375, M376, M377, M378, M379, M380, M381, M382, M383, M384, M385, M386, M387, M388, M389, M390, M391, M392, M393, M394, M395, M396, M397, M398, M399, M400, M401, M402, M403, M404, M405, M406, M407, M408, M409, M410, M411, M412, M413, M414M415, M416, M417, M418, M419, M420, M421, M422, M423, M424, M425, M426, M427, M428, M429, M430, M431, M432, M433, M434, M435, M436, M437, M438, M439, M440, M441, M442, M443, M444, M445, M446, M447, M448, M449, M450, M451, M452, M453, M454, M455, M456, M457, M458, M459, M460, M461, M462, M463, M464, M465, M466, M467, M468, M469, M470, M471, M472, M473, M474, M475, M476, M477, M478, M479, M480, M481, M482, M483, M484, M485, M486, M487, M488, M489, M490, M491, M492, M493, M494, M495, M496, M497, M498, M499, M500, M501, M502, M503, M504, M505, M506, M507, M508, M509, M510, M511, M512, M513, M514, M515, M516, M517, M518, M519, M520, M521, M522, M523, M524, M525, M526, M527, M528, M529, M530, M531, M532, M533, M534, M535, M536, M537, M538, M539, M540, M541, M542, M543, M544, M545, M546, M547, M548, M549, M550, M551, M552, M553, M554, M555, M556, M557, M558, M559, M560, M561, M562, M563, M564, M565, M566, M567, M568, M569, M570, M571, M572, M573, M574, M575, M576, M577, M578, M579, M580, M581, M582, M583, M584, M585, M586, M587, M588, M589, M590, M591, M592, M593, M594, M595, M596, M597, M598, M599, M600, M601, M602, M603, M604, M605, M606, M607, M608, M609, M610, M611, M612, M613, M614M615, M616, M617, M618, M619, M620, M621, M622, M623, M624, M625, M626, M627, M628, M629, M630, M631, M632, M633, M634, M635, M636, M637, M638, M639, M640, M641, M642, M643, M644, M645, M646, M647, M648 are preferably combined with a compound of formula (3) or a compound from Table 4 or 5.

[0205] In the organic electroluminescent device according to the invention comprising at least one phosphorescent emitter, the light emitting layer is preferably an infrared, yellow, orange, red, green, blue or ultraviolet light emitting layer, particularly preferably a yellow or green light emitting layer, and very particularly preferably a green light emitting layer.

[0206] The yellow light emitting layer is here understood to mean a layer whose maximum value of photoluminescence is in the range of 540 to 570 nm. The orange light emitting layer is understood to mean a layer whose maximum value of photoluminescence is in the range of 570 to 600 nm. The red light emitting layer is understood to mean a layer whose maximum value of photoluminescence is in the range of 600 to 750 nm. The green light emitting layer is understood to mean a layer whose maximum value of photoluminescence is in the range of 490 to 540 nm. The blue light emitting layer is understood to mean a layer whose maximum value of photoluminescence is in the range of 440 to 490 nm. The photoluminescence of the layer is here determined by measuring the photoluminescence spectrum of a layer having a layer thickness of 50 nm at room temperature, and this layer contains a combination according to the invention of a host material of formulas (1) and (2) and the corresponding emitter.

[0207] The photoluminescence spectrum of the layer is recorded, for example, using a commercially available photoluminescence spectrometer.

[0208] The photoluminescence spectrum of the selected emitter is generally measured in an oxygen-free solution of 10-5 mol, where the measurement is carried out at room temperature and any solvent in which the selected emitter dissolves at that concentration is suitable. Particularly preferred solvents are usually toluene or 2-methyl-THF, but also dichloromethane. The measurement is carried out using a commercially available photoluminescence spectrometer. The triplet energy T1 in eV is determined from the photoluminescence spectrum of the emitter. First, the peak maximum Plmax. (in nm) of the photoluminescence spectrum is determined. Then, the peak maximum Plmax. (in nm) is converted to units of eV according to E (T1 in eV) = 1240 / E (T1 in nm) = 1240 / Plmax. (in nm).

[0209] Therefore, the preferred phosphorescent emitter is an infrared emitter, and its triplet energy T1 is preferably from about 1.9 eV to about 1.0 eV.

[0210] Therefore, the preferred phosphorescent emitter is preferably a red emitter of formula (3) or from Table 4 or 5, and its triplet energy T1 is preferably from about 2.1 eV to about 1.9 eV.

[0211] Therefore, the preferred phosphorescent emitter is preferably a yellow emitter of formula (3) or from Table 4 or 5, and its triplet energy T1 is preferably from about 2.3 eV to about 2.1 eV.

[0212] Therefore, the preferred phosphorescent emitter is preferably a green emitter of formula (3) or from Table 4 or 5, and its triplet energy T1 is preferably from about 2.5 eV to about 2.3 eV.

[0213] Therefore, the preferred phosphorescent emitter is preferably a blue emitter of formula (3) or from Table 4 or 5, and its triplet energy T1 is preferably from about 3.1 eV to about 2.5 eV.

[0214] Accordingly, preferred phosphorescent emitters are preferably the ultraviolet emitters of formula (3) or from Table 4 or 5, and their triplet energy T1 is preferably from about 4.0 eV to about 3.1 eV.

[0215] Accordingly, particularly preferred phosphorescent emitters are, as described above, preferably the green or yellow emitters of formula (3) or from Table 4 or 5.

[0216] Accordingly, very particularly preferred phosphorescent emitters are preferably the green emitters of formula (3) or from Table 4 or 5, and their triplet energy T1 is preferably from about 2.5 eV to about 2.3 eV.

[0217] The green emitters as described above, preferably of formula (3) or from Table 4 or 5, are very particularly preferably selected for the composition according to the invention or for the emission layer according to the invention.

[0218] The emission layer of the device according to the invention may also contain a fluorescent emitter.

[0219] Preferred fluorescent emitters are selected from the class of arylamines. An arylamine or aromatic amine in the sense of the present invention is understood to mean a compound containing three substituted or unsubstituted aromatic or heteroaromatic ring systems directly bonded to nitrogen. At least one of these aromatic or heteroaromatic ring systems is preferably a condensed ring system, particularly preferably a condensed ring system having at least 14 aromatic ring atoms. Preferred examples thereof are aromatic anthracene amines, aromatic anthracene diamines, aromatic pyrene amines, aromatic pyrene diamines, aromatic chrysene amines or aromatic chrysene diamines. An aromatic anthracene amine is understood to mean a compound in which one diarylamino group is directly bonded to the anthracene group, preferably at the 9-position. An aromatic anthracene diamine is understood to mean a compound in which two diarylamino groups are directly bonded to the anthracene group, preferably at the 9,10-positions. Aromatic pyrene amines, pyrene diamines, chrysene amines and chrysene diamines are defined similarly, and the diarylamino group is preferably bonded to pyrene at the 1-position or 1,6-positions. Further preferred fluorescent emitters are, for example, indenofluorene amines or indenofluorene diamines according to WO2006 / 108497 or WO2006 / 122630, for example benzoindenofluorene amines or benzoindenofluorene diamines according to WO2008 / 006449, and for example dibenzoindenofluorene amines or dibenzoindenofluorene diamines according to WO2007 / 140847, and indenofluorene derivatives containing a condensed aryl group disclosed in WO2010 / 012328.

[0220] In a further preferred embodiment of the present invention, at least one light-emitting layer of the organic electroluminescent device may contain, in addition to the host materials 1 and 2 as described above or as described as preferred, a further host material or matrix material called a so-called mixed matrix system. The mixed matrix system preferably contains 3 or 4 different matrix materials, particularly preferably 3 different matrix materials (i.e., in addition to the host materials 1 and 2 as described above, a further matrix component). Particularly suitable matrix materials that can be used in combination as matrix components of the mixed matrix system are selected from wide bandgap materials, bipolar host materials, electron transport materials (ETMs), and hole transport materials (HTMs).

[0221] The wide bandgap material is here understood to mean a material in the sense of the disclosure of US 7,294,849, which is characterized by a bandgap of at least 3.5 eV, and the bandgap is understood to mean the separation between the HOMO energy and the LUMO energy of the material.

[0222] More precise details regarding the mixed matrix system are described, inter alia, in application WO2010 / 108579. Particularly suitable matrix materials that can be used in combination with the host materials 1 and 2 as described above or as described as preferred as matrix components of the mixed matrix system in a phosphorescent or fluorescent organic electroluminescent device are selected from the preferred matrix materials shown below for phosphorescent emitters or the preferred matrix materials for fluorescent emitters, depending on which type of emitter is used. The mixed matrix system is preferably optimized for emitters of formula (3) or from Table 4 or 5.

[0223] In the device according to the invention, further suitable host materials for the host materials 1 and 2 as described above, preferably for fluorescent phosphors, particularly preferably combinations of host materials selected from M1 to M648, are suitable further host materials which are substances of various classes. Preferred further host materials are oligoarylenes (for example, 2,2',7,7'-tetraphenylspirobifluorene according to EP676461, or dinaphthylanthracene), in particular oligoarylenes containing condensed aromatic groups, oligoarylenevinylenes (for example, DPVBi or spiro-DPVBi according to EP676461), polypodal metal complexes (for example, according to WO2004 / 081017), hole-conductive compounds (for example, according to WO2004 / 058911), electron-conductive compounds, in particular ketones, phosphine oxides, sulfoxides, etc. (for example, according to WO2005 / 084081 and WO2005 / 084082), atropisomers (for example, according to WO2006 / 048268), boronic acid derivatives (for example, according to WO2006 / 117052) or benzoanthracenes (for example, according to WO2008 / 145239). Particularly preferred matrix materials are selected from the class of oligoarylenes containing naphthalene, anthracene, benzoanthracene and / or pyrene or atropisomers of these compounds, oligoarylenevinylenes, ketones, phosphine oxides, and sulfoxides. Highly particularly preferred matrix materials are selected from the class of oligoarylenes containing anthracene, benzoanthracene, benzophenanthrene and / or pyrene or atropisomers of these compounds. It is intended that oligoarylene in the sense of the present invention be understood to mean a compound in which at least three aryl or arylene groups are bonded to each other.

[0224] In the device according to the present invention, in addition to the host materials 1 and 2 as described above, further suitable matrix materials for phosphorescent emitters, particularly preferably combinations of host materials selected from M1 to M648 as described above, are matrix materials of the following classes: aromatic amines, in particular, for example, triarylamines according to US2005 / 0069729, carbazole derivatives (for example, CBP, N,N-biscarbazolylbiphenyl) or compounds according to WO2005 / 039246, US2005 / 0069729, JP2004 / 288381, EP1205527 or WO2008 / 086851, for example, crosslinked carbazole derivatives according to WO2011 / 088877 and WO2011 / 128017, for example, indenocarbazole derivatives according to WO2010 / 136109 and WO2011 / 000455, for example, azacarbazole derivatives according to EP1617710, EP1617711, EP1731584, JP2005 / 347160, for example, indolocarbazole derivatives according to WO2007 / 063754 or WO2008 / 056746, for example, ketones according to WO2004 / 093207 or WO2010 / 006680, for example, phosphine oxides, sulfoxides and sulfones according to WO2005 / 003253, oligophenylene, for example, bipolar matrix materials according to WO2007 / 137725, for example, silanes according to WO2005 / 111172, for example, azaboroles or boronic esters according to WO2006 / 117052, for example, triazine derivatives according to WO2010 / 015306, WO2007 / 063754 or WO2008 / 056746, for example, zinc complexes, aluminum complexes according to EP652273 or WO2009 / 062578, for example, BAlq, for example, diazasilole derivatives and tetraazasilole derivatives according to WO2010 / 054729, for example, diazaphosphole derivatives according to WO2010 / 054730, and aluminum complexes, for example, BAlQ.

[0225] According to an aspect of the present invention, the mixture does not contain additional components, i.e., functional materials, other than the components of the electron-transporting host material of formula (1) and the hole-transporting host material of formula (2). These are material mixtures that are used by themselves to form the light-emitting layer. These mixtures are used as the sole material source during the deposition of the host material for the light-emitting layer and are also called pre-mixed systems that have a certain mixing ratio during deposition. This makes it possible to deposit a layer with uniformly dispersed components in a simple and rapid manner without requiring precise control of a large number of material sources.

[0226] According to an alternative aspect of the present invention, the mixture also contains a phosphorescent emitter as described above in addition to the components of the electron-transporting host material of formula (1) and the hole-transporting host material of formula (2). When a suitable mixing ratio is provided during deposition, this mixture can also be used as the sole material source as described above.

[0227] Therefore, the components or elements of the light-emitting layer of the device according to the present invention can be processed by deposition or from a solution. For this purpose, a material combination of host materials 1 and 2 as described above or described as preferred, and optionally a phosphorescent emitter as described above or described as preferred, is provided in a formulation containing at least one solvent. These formulations can be, for example, solutions, dispersions or emulsions. For this purpose, it may be preferred to use a mixture of two or more solvents.

[0228] Therefore, the present invention further relates to a formulation comprising a mixture according to the present invention, which optionally combines host materials 1 and 2 as described above with a phosphorescent emitter as described above or described as preferred, and at least one solvent.

[0229] Suitable and preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, veratrole, THF, methyl-THF, THP, chlorobenzene, dioxane, phenoxytoluene, especially 3-phenoxytoluene, (-)-fencon, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidinone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, α-terpineol, benzothiazole, butyl benzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane, methyl benzoate, NMP, p-cymene, phenetole, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane, hexamethylindane, or mixtures of these solvents.

[0230] The formulation may also here, likewise, contain at least one further organic or inorganic compound, in particular a further luminescent compound and / or a further matrix material, which is utilized in the light-emitting layer of the device according to the invention. Suitable luminescent compounds and further matrix materials are those already indicated above.

[0231] In the device according to the present invention according to a preferred embodiment, the light-emitting layer and the light-emitting compound comprise, based on the total composition of the light-emitting body and the matrix material, at least one compound of formula (1) and at least one compound of formula (2) according to a preferred embodiment, preferably 99.9 to 1% by volume, more preferably 99 to 10% by volume, particularly preferably 98 to 60% by volume, very particularly preferably 97 to 80% by volume of the matrix material. Correspondingly, in the light-emitting layer in the device according to the present invention, the light-emitting body is preferably 0.1 to 99% by volume, more preferably 1 to 90% by volume, particularly preferably 2 to 40% by volume, very particularly preferably 3 to 20% by volume, based on the total composition of the light-emitting layer consisting of the light-emitting body and the matrix material. When the compound is processed from a solution, instead of the aforementioned amounts in volume %, preferably the corresponding amounts in weight % are used.

[0232] In the light-emitting layer and the light-emitting compound in the device according to the present invention according to a preferred embodiment, preferably, the matrix material of formula (1) and the matrix material of formula (2) are included in a volume ratio of 3:1 to 1:3, preferably 1:2.5 to 1:1, particularly preferably 1:2 to 1:1. When the compound is processed from a solution, instead of the aforementioned ratio in volume %, preferably the corresponding amounts in weight % are used.

[0233] The layer arrangement in the organic electroluminescent device according to the present invention is preferably as follows: Anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode.

[0234] This arrangement of the layers is the preferred arrangement.

[0235] Here, it should be pointed out again that not all of these layers need to be present, and / or additional layers may be present additionally.

[0236] The organic electroluminescent device according to the present invention may include a plurality of light-emitting layers. At least one of the light-emitting layers is a light-emitting layer according to the present invention, which contains at least one compound of formula (1) as the host material 1 and at least one compound of formula (2) as the host material 2 as described above. In this case, these light-emitting layers particularly preferably have a plurality of emission maxima in the range of 380 nm to 750 nm as a whole, and white light emission can be obtained as a whole, that is, they can emit fluorescence or phosphorescence, and various light-emitting compounds that emit blue or yellow or orange or red light are used in the light-emitting layer. A three-layer system, that is, a system having three light-emitting layers is particularly preferred, and the three layers exhibit blue, green, orange or red light emission (for the basic structure, see, for example, WO2005 / 011013). It should be noted that in the case of generating white light, it may be suitable to use a single light-emitting compound used individually that emits light over a wide wavelength range, rather than a plurality of light-emitting body compounds that emit colored light.

[0237] Suitable charge transport materials that can be used in the hole injection or hole transport layer or electron blocking layer or electron transport layer of the organic electroluminescent device according to the present invention are, for example, the compounds disclosed in Y. Shirota et al., Chem. Rev. 2007, 107(4), 953-1010, or other materials used in these layers according to the prior art.

[0238] All materials that can be used in the electron transport layer are materials that are used in the electron transport layer as electron transport materials according to the prior art. Particularly preferred are aluminum complexes such as Alq3, zirconium complexes such as Zrq4, benzimidazole derivatives, triazine derivatives, pyrimidine derivatives, pyridine derivatives, pyrazine derivatives, quinoxaline derivatives, quinoline derivatives, oxadiazole derivatives, aromatic ketones, lactams, boranes, diazaphosphole derivatives, and phosphine oxide derivatives. Further preferred materials are derivatives of the aforementioned compounds as disclosed in JP2000 / 053957, WO2003 / 060956, WO2004 / 028217, WO2004 / 080975, and WO2010 / 072300.

[0239] Preferred hole transport materials are, in particular, materials that can be used in hole transport, hole injection, or electron blocking layers, such as indenofluoreneamine derivatives (e.g., according to WO06 / 122630 or WO06 / 100896), amine derivatives disclosed in EP1661888, hexaazatriphenylene derivatives (e.g., according to WO01 / 049806), amine derivatives containing a condensed aromatic ring (e.g., according to US5,061,569), amine derivatives disclosed in WO95 / 09147, monobenzylindeno[1,2-b]fluoreneamine (e.g., according to WO08 / 006449), dibenzylindeno[1,2-b]fluoreneamine (e.g., according to WO07 / 140847), spirobifluoreneamine (e.g., according to WO2012 / 034627 or unpublished EP12000929.5), fluoreneamine (e.g., according to WO2014 / 015937, WO2014 / 015938, and WO2014 / 015935), spirodibenzopyranamine (e.g., according to WO2013 / 083216), and dihydroacridine derivatives (e.g., according to WO2012 / 150001).

[0240] Suitable as the cathode of the device according to the present invention are metals, metal alloys, or multilayer structures containing various metals having a low work function, such as alkaline earth metals, alkali metals, main group metals, or lanthanoids (e.g., Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). Also suitable are alloys containing an alkali metal or an alkaline earth metal and silver, such as an alloy containing magnesium and silver. In the case of a multilayer structure, a further metal having a relatively high work function, such as Ag or Al, can also be used in addition to the metal, and in that case, combinations of metals, such as Ca / Ag, Mg / Ag, or Ba / Ag, are generally used. It may also be preferable to introduce a thin intermediate layer of a material having a high dielectric constant between the metal cathode and the organic semiconductor. Suitable for this purpose are, for example, alkali metal fluorides or alkaline earth metal fluorides, but also the corresponding oxides or carbonates (e.g., LiF, Li2O, BaF2, MgO, NaF, CsF, Cs2CO3, etc.). Furthermore, lithium quinolate (LiQ) can also be used for this purpose. The layer thickness of this layer is preferably 0.5 to 5 nm.

[0241] The anode preferably contains a material having a high work function. The anode preferably has a work function exceeding 4.5 eV with respect to vacuum. Suitable for this purpose are, on the one hand, metals having a high redox potential, such as Ag, Pt, or Au. On the other hand, metal / metal oxide electrodes (e.g., Al / Ni / NiO x 、Al / PtO x) may also be preferred. Depending on the application, at least one of the electrodes needs to be transparent or partially transparent in order to facilitate either the irradiation of the organic material (organic solar cell) or the coupling of light (OLED, O-laser). Preferred anode materials are here conductive mixed metal oxides. Indium tin oxide (ITO) or indium zinc oxide (IZO) are particularly preferred. Conductive doped organic materials, especially conductive doped polymers are even more preferred. Furthermore, the anode may also consist of a plurality of layers, for example, an inner layer of ITO and an outer layer of a metal oxide, preferably tungsten oxide, molybdenum oxide or vanadium oxide.

[0242] Since the lifetime of the device according to the invention is shortened in the presence of water and / or air, the organic electroluminescent device according to the invention is appropriately (depending on the application) structured, contacts are formed and finally sealed during manufacture.

[0243] The manufacture of the device according to the invention is not restricted here. It is possible to apply one or more organic layers including the light emitting layer by a sublimation process, in which the material is applied by evaporation at an initial pressure of less than 10 -5 mbar, preferably less than 10 -6 mbar in a vacuum sublimation unit. However, it is also possible here to make the initial pressure even lower, for example, less than 10 -7 mbar.

[0244] The organic electroluminescent device according to the invention is preferably characterized in that one or more layers are applied by an OVPD (organic vapor deposition) process or with the aid of carrier gas sublimation, in which case the material is applied at a pressure of 10 -5 mbar to 1 bar. A special case of this process is the OVJP (organic vapor jet printing) process, in which the material is applied directly through a nozzle and thus structured (for example, M.S. Arnold et al., Appl. Phys. Lett. 2008, 92, 053301).

[0245] The organic electroluminescent device according to the present invention preferably further has one or more organic layers containing the composition according to the present invention formed from a solution, for example, by spin coating or by any desired printing process, for example, screen printing, flexographic printing, nozzle printing or offset printing, particularly preferably by LITI (light-induced thermal imaging, thermal transfer printing) or inkjet printing. For this purpose, soluble host materials 1 and 2, as well as the phosphorescent emitter, are required. Processing from a solution has the advantage, for example, that the light-emitting layer can be applied very simply and inexpensively. This technique is particularly suitable for the mass production of organic electroluminescent devices.

[0246] Hybrid processes are also possible, in which, for example, one or more layers are applied from a solution and one or more further layers are applied by vapor deposition.

[0247] These processes are generally known to those skilled in the art and applicable to organic electroluminescent devices.

[0248] Accordingly, the present invention further relates to a method for manufacturing an organic electroluminescent device according to the present invention as described above or as described as preferred, characterized in that the light-emitting layer is applied by vapor deposition, in particular by a sublimation process and / or by an OVPD (organic vapor phase deposition) process and / or with the aid of carrier gas sublimation, or from a solution, in particular by spin coating or a printing process.

[0249] In the case of production by vapor deposition, there are basically two possibilities regarding how the light-emitting layer according to the present invention can be applied or vapor-deposited onto an arbitrarily desired substrate or a previous layer. On the one hand, the materials used may each be present in a single material source and may ultimately be evaporated from various material sources ("co-evaporation"). On the other hand, various materials can be premixed (premixed system), and this mixture can be presented in a single material source, from which it is ultimately evaporated ("premixed evaporation"). This makes it possible to realize the vapor deposition of a light-emitting layer with uniformly dispersed components in a simple and rapid manner without requiring precise control of a large number of material sources.

[0250] Accordingly, the present invention further relates to a method for manufacturing a device according to the present invention, wherein at least one compound of formula (1) as described above or as described preferably above, and at least one compound of formula (2) as described above or as described preferably above are deposited from at least two material sources continuously or simultaneously from the gas phase, optionally together with at least one phosphorescent emitter as described above or as described preferably above, to form a light-emitting layer.

[0251] In a preferred embodiment of the present invention, the light-emitting layer is applied by vapor deposition, and the components of the composition are premixed and evaporated from a single material source.

[0252] Accordingly, the present invention further relates to a method for manufacturing a device according to the present invention, wherein at least one compound of formula (1) and at least one compound of formula (2) are deposited continuously or simultaneously as a mixture from the gas phase, together with at least one phosphorescent emitter, to form a light-emitting layer.

[0253] The present invention further relates to a method for manufacturing a device according to the present invention as described previously or as described as preferred, wherein at least one compound of formula (1) and at least one compound of formula (2) as described previously or as described as preferred are applied from a solution together with at least one phosphorescent emitter to form a light-emitting layer.

[0254] The device according to the present invention is distinguished by the following surprising advantages compared to the prior art.

[0255] The use of the described material combinations of host materials 1 and 2 as described previously leads in particular to an increase in the lifetime of the device.

[0256] As can be seen in the following examples, by comparing the OLED data with combinations from the prior art, it can be observed that the combination according to the present invention of the matrix materials in the EML results in devices with a lifetime increase of about 30 - 70% regardless of the emitter concentration.

[0257] It should be pointed out that modifications of the embodiments described in the present invention are within the scope of the present invention. Each of the features disclosed in the present invention can be replaced by alternative features that serve the same, equivalent, or similar purpose, unless this is explicitly excluded. Therefore, each of the features disclosed in the present invention should be considered, unless otherwise specified, as an example from a comprehensive series or as an equivalent or similar feature.

[0258] All features of the present invention can be combined with each other in any way, provided that the specific features and / or steps are not mutually exclusive. This applies in particular to the preferred features of the present invention. Similarly, the functions of non-essential combinations can be used individually (without combination).

[0259] The teachings regarding the technical effects disclosed with the present invention can be extracted and combined with other examples.

[0260] The present invention will be described in more detail by the following examples, but it is not desired to limit the present invention thereby.

[0261] General method: In all quantum chemical calculations, the Gaussian16 (Rev. B.01) software package is used. The neutral singlet ground state is optimized at the B3LYP / 6-31G(d) level. The HOMO and LUMO values are determined at the B3LYP / 6-31G(d) level for the ground state energy optimized at B3LYP / 6-31G(d). Then, TD-DFT singlet and triplet excitations (vertical excitations) are calculated using the same method (B3LYP / 6-31G(d)), and the structure of the optimized ground state is calculated. Standard settings for SCF and gradient convergence are used.

[0262] In the energy calculation, the HOMO (Alpha occ. eigenvalue) as the final orbital occupied by two electrons and the LUMO (alpha virt. eigenvalue) as the first unoccupied orbital are given in Hartree units, and HEh and LEh represent the HOMO energy in Hartree units and the LUMO energy in Hartree units, respectively. The HOMO and LUMO values in electron volts calibrated with reference to cyclic voltammetry measurements are determined as follows: HOMOcorr = 0.90603 * HOMO - 0.84836 LUMOcorr = 0.99687 * LUMO - 0.72445 The triplet level T1 of the material is defined as the relative excitation energy (eV) of the triplet state having the lowest energy resulting from quantum chemical energy calculations.

[0263] The singlet level S1 is defined as the relative excitation energy (eV) of the singlet state having the second lowest energy resulting from quantum chemical energy calculations.

[0264] The lowest energy singlet state is called S0.

[0265] The methods described herein are independent of the software packages used and always give the same results. Examples of programs frequently used for this purpose are "Gaussian09" (Gaussian Inc.) and Q-Chem 4.1 (Q-Chem, Inc.). In this application, the "Gaussian16, Rev.B.01" software package is used for energy calculations.

[0266] Example 1 Manufacture of OLED The use of the material combinations according to the invention in OLEDs is presented in the following Examples V1 to Ex28 in comparison with material combinations from the prior art (see Tables 6 and 7).

[0267] Pretreatment for Examples V1 to Ex28: A glass plate coated with structured ITO (indium tin oxide) with a thickness of 50 nm is treated with oxygen plasma first and then argon plasma before coating. These plasma-treated glass plates form the substrates to which the OLEDs are applied.

[0268] The OLED basically has the following layer structure: substrate / hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) / emission layer (EML) / optional hole blocking layer (HBL) / electron transport layer (ETL) / optional electron injection layer (EIL) and finally the cathode. The cathode is formed by an aluminum layer with a thickness of 100 nm. The exact structure of the OLED is shown in Table 6. The materials required for the manufacture of the OLED are shown in Table 8. The device data of the OLED are listed in Table 7.

[0269] Examples V1, V2 and V3 are comparative examples containing hole-transporting hosts according to the prior art WO2017 / 178311. In Examples Ex1, Ex2 and Ex3, the corresponding material combinations according to the invention in the EML are used.

[0270] Examples V4 and V5 are comparative examples for the OLED according to the invention of Example Ex4, and Examples V6 and V7 are comparative examples for the OLED according to the invention of Example Ex5 including a symmetrically substituted electron transporting host material according to the prior art. Compound VG1 is derived from, for example, US2016329502. Compound VG2 is described in, for example, US20140299192.

[0271] Examples Ex6 to Ex28 similarly show data of the OLED according to the invention.

[0272] All materials are applied by thermal evaporation in a vacuum chamber. The light-emitting layer here always consists of at least one matrix material (likewise host material), in the sense of the invention at least two matrix materials, and a light-emitting dopant (lumophore) which is mixed and added to the matrix material(s) in a specific volume ratio by co-evaporation. Expressions such as E1:IC3:TEG1 (33%:60%:7%) here mean that in a layer with a thickness of 30 nm, material E1 is present in the layer as host material 1 at a ratio of 33% by volume, compound IC3 as host material 2 at a ratio of 60%, and TEG1 at a ratio of 7%. Similarly, the electron transport layer may also consist of a mixture of two materials.

[0273] The OLED is characterized by standard methods. For this purpose, the electroluminescence spectrum and the characteristic curve of current / voltage / luminous flux density (IUL characteristic curve) are measured. From these, the EQE and the current efficiency CE (in cd / A units) are calculated. The calculation of CE is performed assuming Lambert emission characteristics.

[0274] The lifetime LT is, in mA / cm 2 when operating at a constant current density j0, the time until the luminous flux density decreases from the initial luminous flux density L0 (in cd / m 2 units) to a specific ratio L1 (in cd / m 2 units). The expression L1 / L0 = 80% in Table 7 means that the lifetime shown in the LT column corresponds to the time (in h units) until the luminous flux density decreases to 80% of the initial value (L0).

[0275] Use of the mixture according to the invention in OLEDs The material combination according to the invention can be used in the light-emitting layer of a phosphorescent green OLED. The combinations according to the invention of compounds E1 to E16 and compounds BC1 to BC17 are used in Examples Ex1 and Ex28 as matrix materials of the light-emitting layer as described in Table 6.

[0276] When comparing the examples according to the invention with the corresponding comparative examples (see above), it is clear that the examples according to the invention exhibit clear advantages in the lifetime of the devices in each case.

[0277]

Table 6-1

[0278]

Table 6-2

[0279]

Table 7

[0280]

Table 8-1

[0281]

Table 8-2

[0282]

Table 8-3

[0283]

Table 8-4

[0284]

Table 8-5

[0285]

Table 8-6

[0286]

Table 8-7

[0287] Example 2 Synthesis of the host material and its precursor: a) 2-dibenzofuran-1-yl-4,6-diphenyl-1,3,5-triazine

[0288]

Chem.

[0289] 23 g (110.0 mmol) of dibenzofuran-1-boronic acid, 29.5 g (110.0 mmol) of 2-chloro-4,6-diphenyl-1,3,5-triazine and 21 g (210.0 mmol) of sodium carbonate are suspended in 500 ml of ethylene glycol diamine ether and 500 ml of water. To this suspension, 913 mg (3.0 mmol) of tri-o-tolylphosphine is added, followed by 112 mg (0.5 mmol) of palladium(II) acetate, and the reaction mixture is heated under reflux for 16 hours. After cooling, the organic phase is separated, filtered through silica gel, washed three times with 200 ml of water, and then evaporated to dryness. The residue is recrystallized from toluene and dichloromethane / heptane. The yield is 37 g (94 mmol), corresponding to 87% of the theoretical value.

[0290] Similarly, the following compounds can also be obtained:

[0291]

Chem.

[0292] [Chemical]

[0293] [Chemical]

[0294] [Chemical]

[0295] b) 2-(8-Bromodibenzofuran-1-yl)-4,6-diphenyl-1,3,5-triazine

[0296] [Chemical]

[0297] 70 g (190.0 mmol) of 2-dibenzofuran-1-yl-4,6-diphenyl-1,3,5-triazine is suspended in 2000 ml of acetic acid (100%) and 2000 ml of sulfuric acid (95 - 98%). 34 g (190 mmol) of NBS is added portionwise to this suspension, and the mixture is stirred in the dark for 2 hours. Then, water / ice is added, the solid is separated, and washed with ethanol. The residue is recrystallized from toluene. The yield is 80 g (167 mmol), corresponding to 87% of the theoretical value.

[0298] Similarly, the following compounds are also prepared:

[0299] [Chemical]

[0300] In the case of the thiophene derivative, nitrobenzene is used instead of sulfuric acid, and elemental bromine is used instead of NBS.

[0301] c) 2,4-Diphenyl-6-[8-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-dibenzofuran-1-yl]-1,3,5-triazine

[0302]

Chem.

[0303] 60 g (125 mmol) of 2-(8-bromodibenzofuran-1-yl)-4,6-diphenyl-1,3,5-triazine is dissolved in 900 ml of anhydrous DMF in a 500 ml flask together with 39 g (1051 mmol) of bis(pinacolato)diboron (CAS 73183-34-3) under a protective gas and degassed for 30 minutes. Subsequently, 37 g (376 mmol) of potassium acetate and 1.9 g (8.7 mmol) of palladium acetate are added, and the batch is heated at 80 °C overnight. When the reaction is complete, the mixture is diluted with 300 ml of toluene and extracted with water. The solvent is removed by rotary evaporator and the product is recrystallized from heptane. Yield: 61 g (117 mmol), 94% of theory.

[0304] Similarly, the following compounds are also prepared:

[0305]

Chem.

[0306] d) 2-[4-[9-(4,6-Diphenyl-1,3,5-triazin-2-yl)dibenzofuran-2-yl]phenyl]-4,6-diphenyl-1,3,5-triazine

[0307]

Chem.

[0308] 68.7 g (110.0 mmol) of 2,4-diphenyl-6-[8-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)dibenzofuran-1-yl]-1,3,5-triazine, 42 g (110.0 mmol) of 2-(4-bromophenyl)-4,6-diphenyl-1,3,5-triazine and 21 g (210.0 mmol) of sodium carbonate are suspended in 500 ml of ethylene glycol diamine ether and 500 ml of water. To this suspension, 913 mg (3.0 mmol) of tri-o-tolylphosphine is added, followed by 112 mg (0.5 mmol) of palladium(II) acetate, and the reaction mixture is heated under reflux for 16 h. After cooling, the organic phase is separated, filtered through silica gel, washed three times with 200 ml of water and then evaporated to dryness. The product is purified by column chromatography on silica gel using toluene / CHCl3 (1:1) and finally sublimed under high vacuum (p = 5×10 -7 mbar) (purity 99.9%). The yield is 64 g (81 mmol), corresponding to 70% of the theoretical value.

[0309] Similarly, the following compounds can also be prepared:

[0310]

Chemical formula

[0311]

Chemical formula

[0312]

Chemical formula

[0313]

Chemical formula

Claims

1. An organic electroluminescent device comprising an anode, a cathode, and at least one organic layer including at least one light-emitting layer, wherein the at least one light-emitting layer comprises at least one compound of formula (1) as host material 1, at least one compound of formula (2) as host material 2, and at least one phosphorescent emitter of formula (3): 【Chemical 1】 (wherein, Y is selected from O, S, C(CH ３ ) ２ , C(phenyl) ２ or 【Chemical 2】 and in the formula, ＊ represents a C atom bonded to the remaining part of the formula (1), L is a divalent linker L-1 to L-26: 【Chemical 3】 selected from one of them, and in the formula, the linkers L-1 to L-26 may also be substituted by one or more substituents R, W is O, S or C(CH ３ ) ２ and a is 0 or 1, b is 0 or 1, R is, each time it appears, the same or different, and is selected from the group consisting of CN, a linear alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms, or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, an aryloxy or heteroaryloxy group having 5 to 40 aromatic ring atoms, or an aralkyl or heteroaralkyl group having 5 to 40 aromatic ring atoms, Ar １Each time it appears, it is an aryl or heteroaryl group having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R, and is independent of each other in each case. K and M are, in each case, independently of each other, an aromatic ring system having 6 to 40 aromatic ring atoms, which is unsubstituted, or partially or fully deuterated, or monosubstituted by R when x and y represent 0, where x １ and y １ represents 0, or is substituted by R when x and y represent 0, or is monosubstituted by R, or ＊ is monosubstituted by R, or K and M are, in each case, independently of each other, a heteroaromatic ring system having 14 to 40 ring atoms together with X or X １ when the values of x, x1, y and / or y1 represent 1. x and x1 are, in each case, independently of each other, 0 or 1 each time they appear. y and y1 are, in each case, independently of each other, 0 or 1 each time they appear. X and X １ are, in each case, independently of each other, a bond or C(R#) ２ each time they appear. R ０ is, each time it appears, independently of each other, an unsubstituted or partially or fully deuterated aromatic ring system having 6 to 18 C atoms. R ＊ is dibenzofuranyl or dibenzothiophenyl. R# is, each time it appears, independently of each other, a linear or branched alkyl group having 1 to 4 C atoms. c, d, e and f are independently of each other 0 or 1. n + m is 3, n is 1 or 2, and m is 2 or 1. X' is N or CR'. R′ is H, D, or a branched or linear alkyl group having 1 to 10 C atoms, or a partially or fully deuterated branched or linear alkyl group having 1 to 10 C atoms, or a cycloalkyl group having 4 to 7 C atoms which may be partially or fully substituted by deuterium) An organic electroluminescent device comprising

2. The organic electroluminescent device according to claim 1, wherein Y in the host material 1 represents O.

3. The host material 2 is of formula (2a), (2b) or (2c): [Chemical Formula 4] (wherein the symbols and subscripts X, X １ , R ０ , c, d, e and f have the meanings as in claim 1, K and M in the compound of formula (2a) each independently represent, in each case, an aromatic ring system having 6 to 40 aromatic ring atoms, which is unsubstituted, or partially or fully deuterated, or mono-substituted by R ＊ . M in the compound of formula (2b) represents an aromatic ring system having 6 to 40 aromatic ring atoms, which is unsubstituted, or partially or fully deuterated, or mono-substituted by R ＊ . K in the compound of formula (2b) together with X forms a heteroaromatic ring system having 14 to 40 ring atoms, and x and y in the compound of formula (2b) each independently represent, in each case, 0 or 1, and the sum of x and y represents at least 1, K and M in the compound of formula (2c) each independently represent, in each case, a heteroaromatic ring system having 14 to 40 ring atoms together with X or X １ , and In the compound of the formula (2c), x, x1, y, and y1 each independently represent 0 or 1 in each case, the sum of x and y represents at least 1, and the sum of x1 and y1 represents at least 1.) The organic electroluminescent device according to claim 1 or 2, characterized in that it conforms to one of the following.

4. The organic electroluminescent device according to any one of claims 1 to 3, characterized in that L in the host material 1 is selected from the divalent linkers L-1 to L-13 and L-24 to L-26.

5. The organic electroluminescent device according to any one of claims 1 to 4, characterized in that the organic electroluminescent device is an electroluminescent device selected from an organic light-emitting transistor (OLET), an organic field quenching device (OFQD), an organic light-emitting electrochemical cell (OLEC), an organic laser diode (O-laser), and an organic light-emitting diode (OLED).

6. The organic electroluminescent device according to any one of claims 1 to 5, characterized in that, in addition to the light-emitting layer (EML), the organic electroluminescent device includes a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), an electron injection layer (EIL), and / or a hole blocking layer (HBL).

7. A method for manufacturing the device according to any one of claims 1 to 6, characterized in that the light-emitting layer is deposited by vapor deposition or coated from a solution.

8. The method according to claim 7, characterized in that at least one compound of the formula (1) and at least one compound of the formula (2) are deposited continuously or simultaneously from at least two material sources in the gas phase together with the at least one phosphorescent emitter to form the light-emitting layer.

9. At least one compound of the formula (1) and at least one compound of the formula (2) are deposited as a mixture from the gas phase continuously or simultaneously together with the at least one phosphorescent emitter to form the light-emitting layer, the method according to claim 7, characterized in that.

10. At least one compound of the formula (1) and at least one compound of the formula (2) are applied from a solution together with the at least one phosphorescent emitter to form the light-emitting layer, the method according to claim 7, characterized in that.

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