Electronic Devices

Abstract

The present application relates to an electronic device comprising an organic layer which in turn contains a mixture of at least two different compounds.

Description

[0001] The present application relates to an electronic device, which comprises an anode, a hole injection layer, a hole transport layer, a light-emitting layer and a cathode in sequence. The hole transport layer contains a first compound selected from spirobifluorenamine and fluorenamine compounds, and a second compound different from the first compound and selected from spirobifluorenamine and fluorenamine compounds.

[0002] Electronic devices in the context of this application are understood to mean so-called organic electronic devices, which contain organic semiconductor materials as functional materials. More particularly, these are understood to mean OLEDs (organic light emitting diodes, organic electroluminescent devices). These electronic devices have one or more layers containing organic compounds and emit light when a voltage is applied. The general principles of the construction and operation of OLEDs are known to those skilled in the art.

[0003] A hole injection layer is understood to mean a layer which supports the injection of holes from the anode of the OLED into the hole transport layer during operation of the electronic device. The hole injection layer preferably directly adjoins the anode and one or more hole transport layers directly adjoin the hole injection layer on the cathode side.

[0004] A hole transport layer is understood to be a layer which is able to transport holes during operation of the electronic device. More particularly, it is a layer which is arranged in an OLED between the anode and the light-emitting layer closest to the anode.

[0005] In electronic devices, especially OLEDs, there is great interest in improving the performance data, especially lifetime, efficiency, operating voltage and color purity. In these areas, no completely satisfactory solutions have yet been found.

[0006] Hole transport layers have a significant influence on the above-mentioned performance data of the electronic device. They can be present as a single hole transport layer between anode and light-emitting layer or in the form of a plurality of hole transport layers, for example 2 or 3 hole transport layers, between anode and light-emitting layer.

[0007] The hole transport layer materials known in the prior art are mainly amine compounds, especially triarylamine compounds. Examples of such triarylamine compounds are spirodifluoreneamine, fluoreneamine, indenofluoreneamine, phenanthrenamine, carbazoleamine, xantheneamine, spirodihydroacridinamine, benzidine and combinations of these structural elements having one or more amino groups, which is only a selection, and those skilled in the art know other structural categories.

[0008] It has now been found that an electronic device comprising, in sequence, an anode, a hole injection layer, a hole transport layer, a light-emitting layer and a cathode, wherein the hole transport layer contains a first compound selected from spirobifluorenamine and fluorenamine compounds and a second compound selected from spirobifluorenamine and fluorenamine compounds, different from the first compound, has better performance data than prior art electronic devices in which the hole transport layer is formed from a single compound. More particularly, the lifetime and / or efficiency of such a device is improved compared to the above-mentioned prior art devices.

[0009] The present application thus provides an electronic device comprising

[0010] -anode,

[0011] -cathode,

[0012] - a light-emitting layer arranged between the anode and the cathode,

[0013] - a hole injection layer arranged between the anode and the light-emitting layer;

[0014] a hole transport layer which is arranged between the hole injection layer and the light-emitting layer and directly adjoins the light-emitting layer on the anode side and which contains two different compounds which correspond to the same or different formulae selected from the group consisting of formulae (I) and (II),

[0015]

[0016]

[0017] in

[0018] Z is the same or different in each occurrence and is selected from CR 1 and N, where When the group is bonded thereto, Z is C;

[0019] X is the same or different at each occurrence and is selected from a single bond, O, S, C(R 1 )2 and NR 1 ;

[0020] Ar 1 and Ar 2 are the same or different at each occurrence and are selected from a group consisting of 6 to 40 aromatic ring atoms and surrounded by one or more R 2 Aromatic ring systems substituted with a group, and having 5 to 40 aromatic ring atoms and substituted with one or more R 2 Group-substituted heteroaromatic ring systems;

[0021] R 1 and R 2 is the same or different at each occurrence and is selected from: H, D, F, Cl, Br, I, C(=O)R 3,CN,Si(R 3 )3,N(R 3 )2,P(=O)(R 3 )2,OR 3 , S(=O)R 3 , S(=O)2R 3 , straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherein two or more R 1 or R 2 The radicals may be linked to one another and may form a ring; wherein the alkyl, alkoxy, alkenyl and alkynyl radicals mentioned and the aromatic and heteroaromatic ring systems mentioned are each replaced by R 3 and wherein the alkyl, alkoxy, alkenyl and alkynyl groups mentioned in one or more CH2 groups can be -R 3 C=CR 3 -、-C≡C-、Si(R 3 )2. C=O, C=NR 3 、-C(=O)O-、-C(=O)NR 3 -、NR 3 ,P(=O)(R 3 ), -O-, -S-, SO or SO2;

[0022] R 3 is the same or different at each occurrence and is selected from: H, D, F, Cl, Br, I, CN, an alkyl or alkoxy group having 1 to 20 carbon atoms, an alkenyl or alkynyl group having 2 to 20 carbon atoms, an aromatic ring system having 6 to 40 aromatic ring atoms, and a heteroaromatic ring system having 5 to 40 aromatic ring atoms; wherein two or more R 3 The groups may be connected to each other and may form a ring; and the alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems mentioned therein may be substituted by one or more groups selected from F and CN;

[0023] n is 0, 1, 2, 3 or 4, wherein when n=0, Ar 1 The group is not present and the nitrogen atom is directly bonded to the rest of the formula.

[0024] When n = 2, two Ar 1 The groups are successfully bonded continuously, which is -Ar 1 -Ar 1 -. When n = 3, three Ar 1 The groups are successfully bonded continuously, which is -Ar1 -Ar 1 -Ar 1 -. When n = 4, the four Ar 1 The groups are successfully bonded continuously, which is -Ar 1 -Ar 1 -Ar 1 -Ar 1 -.

[0025] The following definitions are applicable to chemical groups used in this application. Unless any more specific definitions are given, they are applicable.

[0026] Aryl groups in the context of the present invention are understood to refer to single aromatic rings, i.e. benzene, or fused aromatic polycyclics, such as naphthalene, phenanthrene or anthracene. The fused aromatic polycyclics in the context of the present application are composed of two or more single aromatic rings fused to each other. The fusion between the rings is understood to refer to the rings having at least one edge in common with each other. Aryl groups in the context of the present invention contain 6 to 40 aromatic ring atoms. In addition, aryl groups do not contain any heteroatoms as aromatic ring atoms.

[0027] The heteroaryl group in the context of the present invention is understood to refer to a single heteroaromatic ring, such as pyridine, pyrimidine or thiophene, or a fused heteroaromatic polycyclic, such as quinoline or carbazole. The fused heteroaromatic polycyclic in the context of the present application is composed of two or more single aromatic or heteroaromatic rings fused to each other, wherein at least one of the aromatic and heteroaromatic rings is a heteroaromatic ring. The fusion between the rings is understood to refer to the rings having at least one edge in common with each other. The heteroaryl group in the context of the present invention contains 5 to 40 aromatic ring atoms, at least one of which is a heteroatom. The heteroatoms of the heteroaryl group are preferably selected from N, O and S.

[0028] Aryl or heteroaryl radicals which may in each case be substituted by the abovementioned radicals are understood in particular to mean radicals derived from benzene, naphthalene, anthracene, phenanthrene, pyrene, dihydropyrene, letrozole, perylene, terphenylene, fluoranthene, benzanthracene, triphenylene, tetracene, pentacene, benzopyrene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenanthrene, pyridine, pyridine, quinoline ... azine, pyrazole, indazole, imidazole, benzimidazole, benzimidazole [1,2-a] benzimidazole, naphthimidazole, phenanthimidazole, pyridimidazole, pyrazimidazole, quinoxalimidazole, Azoles, benzo Azoles, naphtho Azoles, anthracenes Azoles, phenanthracenes Azoles, Isopropylamine oxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, pyrazine, phenazine, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3- Oxadiazole, 1,2,4- Oxadiazole, 1,2,5- 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.

[0029] The aromatic ring system in the context of the present invention is a system that does not necessarily contain only an aryl group, but may also contain one or more non-aromatic rings fused to at least one aryl group. These non-aromatic rings contain only carbon atoms as ring atoms. Examples of groups encompassed by this definition are tetralin, fluorene and spirobifluorene. In addition, the term "aromatic ring system" includes a system consisting of two or more aromatic ring systems connected to each other via a single bond, such as biphenyl, terphenyl, 7-phenyl-2-fluorenyl, quaterphenyl and 3,5-diphenyl-1-phenyl. The aromatic ring system in the context of the present invention contains 6 to 40 carbon atoms and has no heteroatoms in the ring system. The definition of "aromatic ring system" does not include heteroaryl groups.

[0030] The heteroaromatic ring system conforms to the above-mentioned definition of an aromatic ring system, except that it must contain at least one heteroatom as a ring atom. As in the case of an aromatic ring system, a heteroaromatic ring system need not contain only aryl groups and heteroaryl groups, but may also contain one or more non-aromatic rings fused to at least one aryl or heteroaryl group. The non-aromatic rings may contain only carbon atoms as ring atoms, or they may also contain one or more heteroatoms, wherein the heteroatoms are preferably selected from N, O and S. An example of such a heteroaromatic ring system is benzopyranyl. In addition, the term "heteroaromatic ring system" is understood to refer to a system consisting of two or more aromatic or heteroaromatic ring systems bonded to each other via a single bond, such as 4,6-diphenyl-2-triazinyl. The heteroaromatic ring system in the context of the present invention contains 5 to 40 ring atoms selected from carbon and heteroatoms, wherein at least one ring atom is a heteroatom. The heteroatoms of the heteroaromatic ring system are preferably selected from N, O and S.

[0031] Thus, the terms "heteroaromatic ring system" and "aromatic ring system" as defined in this application differ from each other in that an aromatic ring system cannot have heteroatoms as ring atoms, whereas a heteroaromatic ring system must have at least one heteroatom as a ring atom. The heteroatom may be present as a ring atom of a non-aromatic heterocycle or as a ring atom of an aromatic heterocycle.

[0032] According to the above definition, any aryl group is encompassed by the term "aromatic ring system" and any heteroaryl group is encompassed by the term "heteroaromatic ring system".

[0033] Aromatic ring systems with 6 to 40 aromatic ring atoms or heteroaromatic ring systems with 5 to 40 aromatic ring atoms are understood in particular to mean radicals derived from the radicals mentioned above under aryl radicals and heteroaryl radicals, and also radicals derived from biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, indenofluorene, trimerized indene, isotrimerized indene, spirotrimerized indene, spiroisotrimerized indene, indenocarbazole or radicals derived from combinations of these radicals.

[0034] In the context of the present invention, straight-chain alkyl radicals having 1 to 20 carbon atoms, branched or cyclic alkyl radicals having 3 to 20 carbon atoms and alkenyl or alkynyl radicals having 2 to 40 carbon atoms, in which individual hydrogen atoms or CH2 groups may also be substituted by the radicals mentioned above under the definition of these radicals, are preferably understood to mean methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, 2- , n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, vinyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl or octynyl group.

[0035] Alkoxy or thioalkyl radicals having 1 to 20 carbon atoms, in which individual hydrogen atoms or CH2 groups may also be replaced by radicals mentioned above under the definition of these radicals, are preferably understood as meaning methoxy, trifluoromethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, sec-pentoxy, 2-methylbutoxy, n-hexyloxy, cyclohexyloxy, n-heptyloxy, cycloheptyloxy, n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy, 2,2,2-trifluoroethoxy, methylthio, ethylthio, n-propylthio wherein the group is selected from the group consisting of: 1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1,2-difluoro-1

[0036] In the context of the present invention, the expression that two or more groups together can form a ring is to be understood as meaning in particular that the two groups are connected to each other via a chemical bond. In addition, however, the above expression is also to be understood as meaning that, if one of the two groups is hydrogen, the second group is bonded to the position to which the hydrogen atom is bonded, thereby forming a ring.

[0037] The electronic device is preferably an organic electroluminescent device (OLED).

[0038] Preferred anodes are materials with a high work function. Preferably, the anode has a work function greater than 4.5 eV relative to vacuum. Firstly, metals with a high redox potential, such as Ag, Pt or Au, are suitable for this purpose. Secondly, metal / metal oxide electrodes (such as Al / Ni / NiO x 、Al / PtO x ). For some applications, at least one of the electrodes should be transparent or partially transparent to facilitate the illumination (organic solar cells) or luminescence (OLED, O-laser) of the organic material. Preferred anode materials here are conductive mixed metal oxides. Particularly preferred are indium tin oxide (ITO) or indium zinc oxide (IZO). Also preferred are conductive doped organic materials, especially conductive doped polymers. In addition, the anode can also consist of two or more layers, for example of an inner layer of ITO and an outer layer of a metal oxide, preferably tungsten oxide, molybdenum oxide or vanadium oxide.

[0039] The preferred cathode of the electronic device is a metal with a low work function, a metal alloy or a multilayer structure consisting of a variety of metals, such as alkaline earth metals, alkali metals, main group metals or lanthanides (such as Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). In addition, it is suitable to be an alloy consisting of an alkali metal or alkaline earth metal and silver, such as an alloy consisting of magnesium and silver. In the case of a multilayer structure, in addition to the metals mentioned, other metals with a relatively high work function can also be used, such as Ag or Al, in which case a combination of the metals is usually used, such as Ca / Ag, Mg / Ag or Ba / Ag. It is also possible to preferably introduce a thin intermediate layer of a material with a high dielectric constant between the metal cathode and the organic semiconductor. Examples of materials useful for this purpose are fluorides of alkali metals or alkaline earth metals, and corresponding oxides or carbonates (such as LiF, Li2O, BaF2, MgO, NaF, CsF, Cs2CO3, etc.). Lithium quinoline (LiQ) can also be used for this purpose. The layer thickness of this layer is preferably between 0.5nm and 5nm.

[0040] The light-emitting layer of the device can be a fluorescent or phosphorescent light-emitting layer. The light-emitting layer of the device is preferably a fluorescent light-emitting layer, and a light-emitting layer emitting blue fluorescence is particularly preferred. In the fluorescent light-emitting layer, the light emitter is preferably a singlet light emitter, that is, a compound that emits light from an excited singlet state during device operation. In the phosphorescent light-emitting layer, the light emitter is preferably a triplet light emitter, that is, a compound that emits light from an excited triplet state, or from a state with a higher spin quantum number, such as a quintet state, during device operation.

[0041] In a preferred embodiment, the fluorescent emitting layer used is a blue-fluorescing layer.

[0042] In a preferred embodiment, the phosphorescent emitting layer used is a green or red phosphorescent emitting layer.

[0043] Suitable phosphorescent emitters are, in particular, compounds which, when suitably excited, emit light preferably in the visible region and which furthermore contain at least one atom having an atomic number greater than 20, preferably greater than 38 and less than 84, more preferably greater than 56 and less than 80. Preferred for use as phosphorescent emitters are compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold or europium, in particular compounds containing iridium, platinum or copper.

[0044] In general, all phosphorescent complexes which are used according to the prior art for phosphorescent OLEDs and which are known to the person skilled in the art in the field of electroluminescent devices are suitable for use in the device according to the invention.

[0045] The following table shows preferred compounds for use as phosphorescent emitters:

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056] Preferred fluorescent emitting compounds are selected from the class of arylamines. Arylamines or aromatic amines in the context of the present invention are understood to mean compounds containing three substituted or unsubstituted aromatic or heteroaromatic ring systems directly bonded to nitrogen. Preferably, at least one of these aromatic or heteroaromatic ring systems is a fused ring system, more preferably a fused ring system having at least 14 aromatic ring atoms. The above preferred examples are aromatic anthraceneamines, aromatic anthracenediamines, aromatic pyreneamines, aromatic pyrenediamines, aromatic leucine or aromatic leucine diamines. Aromatic anthraceneamines are understood to mean compounds in which one diarylamino group is directly bonded to an anthracene group, preferably directly bonded at the 9 position. Aromatic anthracenediamines are understood to mean compounds in which two diarylamino groups are directly bonded to anthracene groups, preferably directly bonded at the 9,10 positions. The definitions of aromatic pyreneamines, pyrenediamines, leucine and leucine diamines are similar, wherein the diarylamino groups are preferably bonded to pyrene at the 1 position or at the 1,6 position. Other preferred luminescent compounds are indenofluorenamine or indenofluorenediamine, benzoindenofluorenamine or benzoindenofluorenediamine, and dibenzoindenofluorenamine or dibenzoindenofluorenediamine, and indenofluorene derivatives with fused aryl groups. Also preferred are pyrene arylamines. Also preferred are benzoindenofluorenamine, benzofluorenamine, extended benzoindenofluorene, phenanthene ... Oxazine and fluorene derivatives connected to furan units or thiophene units.

[0057] The following table shows preferred compounds for use as fluorescent emitters:

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065] In a preferred embodiment, the light-emitting layer of the electronic device contains exactly one matrix compound. A matrix compound is understood to mean a compound which is not a light-emitting compound. This embodiment is particularly preferred in the case of fluorescent light-emitting layers.

[0066] In an alternative preferred embodiment, the light-emitting layer of the electronic device contains exactly two or more, preferably exactly two, matrix compounds. This embodiment, also referred to as mixed-matrix system, is particularly preferred in the case of phosphorescent light-emitting layers.

[0067] In the case of a phosphorescent emitting layer, the total proportion of all matrix materials is preferably between 50.0% and 99.9%, more preferably between 80.0% and 99.5%, most preferably between 85.0% and 97.0%.

[0068] The proportion figures in % are understood here to mean proportions in % by volume in the case of layers applied from the gas phase and proportions in % by weight in the case of layers applied from solution.

[0069] Accordingly, the proportion of the phosphorescent compound is preferably between 0.1% and 50.0%, more preferably between 0.5% and 20.0%, most preferably between 3.0% and 15.0%.

[0070] In the case of a fluorescent emitting layer, the total proportion of all matrix materials is preferably between 50.0% and 99.9%, more preferably between 80.0% and 99.5%, most preferably between 90.0% and 99.0%.

[0071] Accordingly, the proportion of the fluorescent compound is between 0.1% and 50.0%, more preferably between 0.5% and 20.0%, most preferably between 1.0% and 10.0%.

[0072] The mixed matrix system preferably comprises two or three different matrix materials, more preferably two different matrix materials. Preferably, in this case, one of the two materials is a material whose properties include hole transport properties, and the other material is a material whose properties include electron transport properties. Other matrix materials that may be present in the mixed matrix system are compounds (wide bandgap materials) with a large energy difference between HOMO and LUMO. The two different matrix materials may be present in a ratio of 1:50 to 1:1, preferably 1:20 to 1:1, more preferably 1:10 to 1:1 and most preferably 1:4 to 1:1. It is preferred to use a mixed matrix system in a phosphorescent organic electroluminescent device.

[0073] Preferred matrix materials for fluorescent emitting compounds are selected from the following classes: oligoarylene groups (e.g. 2,2',7,7'-tetraphenylspirobifluorene), in particular oligoarylene groups containing fused aromatic groups, oligoarylene vinylene groups, polypodal metal complexes, hole-conducting compounds, electron-conducting compounds, in particular ketones, phosphine oxides and sulfoxides; atropisomers, boronic acid derivatives, and benzanthracene. Particularly preferred matrix materials are selected from the following classes: oligoarylene groups containing naphthalene, anthracene, benzanthracene and / or pyrene or atropisomers of these compounds, oligoarylene vinylene groups, ketones, phosphine oxides, and sulfoxides. Very particularly preferred matrix materials are selected from the following classes: oligoarylene groups containing anthracene, benzanthracene, triphenylene and / or pyrene or atropisomers of these compounds. Oligoarylene groups in the context of the present invention should be understood as meaning compounds in which at least three aryl or arylene groups are bonded to one another.

[0074] The following table shows preferred host materials for fluorescent light-emitting compounds:

[0075]

[0076]

[0077]

[0078]

[0079] Preferred matrix materials for phosphorescent emitters are aromatic ketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones, triarylamines, carbazole derivatives, for example CBP (N,N-biscarbazolylbiphenyl), indolocarbazole derivatives, indenocarbazole derivatives, azacarbazole derivatives, bipolar matrix materials, silanes, azaboroles or boric esters, triazine derivatives, zinc complexes, diazasilole or tetraazasilole derivatives, diazaphosphole derivatives, bridged carbazole derivatives, terphenylidene derivatives, or lactams.

[0080] In a preferred embodiment, the electronic device contains exactly one light-emitting layer.

[0081] In an alternative preferred embodiment, the electronic device contains a plurality of light-emitting layers, preferably 2, 3 or 4 light-emitting layers. This is particularly preferred for white light-emitting electronic devices.

[0082] More preferably, in this case the emitting layer as a whole has several emission peaks between 380 nm and 750 nm, so that the electronic device emits white light; in other words, a plurality of emitting compounds are used in the emitting layer which can fluoresce or phosphoresce and emit blue, green, yellow, orange or red light. Particularly preferred are three-layer systems, i.e. systems with three emitting layers, wherein in each case one of the three layers exhibits blue emission, in each case one of the three layers exhibits green emission and in each case one of the three layers exhibits orange or red emission. To generate white light, it is also possible to use a single emitter compound which emits in a wide wavelength range instead of a plurality of colored emitter compounds.

[0083] In a preferred embodiment of the invention, the electronic device comprises two or three, preferably three identical or different layer sequences, which are stacked one on top of the other, wherein each layer sequence comprises the following layers: hole injection layer, hole transport layer, electron blocking layer, light-emitting layer and electron transport layer, and wherein at least one, preferably all, of the layer sequences comprise the following layers:

[0084] - a hole injection layer arranged between the anode and the light-emitting layer;

[0085] a hole transport layer arranged between the hole injection layer and the light-emitting layer and directly adjoining the light-emitting layer on the anode side, which contains two different compounds of the same or different formulae selected from the group consisting of formulae (I) and (II).

[0086] Preferably, a double layer consisting of adjacent n-CGL and p-CGL is arranged between the layer sequences, wherein the n-CGL is arranged on the anode side and the p-CGL is correspondingly arranged on the cathode side. CGL here means charge generation layer. The materials for such a layer are known to the person skilled in the art. Preferably, p-doped amines are used in the p-CGL, more preferably materials from the preferred hole transport material structural classes mentioned below.

[0087] The layer thickness of the hole transport layer is preferably 20 nm to 300 nm, more preferably 30 nm to 250 nm. It is further preferred that the layer thickness of the hole transport layer is not greater than 250 nm.

[0088] Preferably, the hole transport layer contains exactly 2, 3 or 4, preferably exactly 2 or 3, most preferably exactly 2 different compounds conforming to the same or different formulae selected from formulae (I) and (II).

[0089] Preferably, the hole transport layer consists of compounds that conform to the same or different formulae selected from formulae (I) and (II). "Consisting of" is understood here to mean that no other compounds are present in the layer, and small amounts of impurities that are usually present during the production of OLEDs are not counted as other compounds in the layer.

[0090] In an alternative preferred embodiment, in addition to the compound conforming to the same or different formula selected from formulae (I) and (II), the hole transport layer further contains a p-type dopant.

[0091] The p-type dopants used in the present invention are preferably organic electron acceptor compounds that are capable of oxidizing one or more of the other compounds in the mixture.

[0092] Particularly preferred p-type dopants are quinone dimethane compounds, azaindenofluorenediones, azaphenalenes, azaterphenylidenes, I2, metal halides, preferably transition metal halides, metal oxides, preferably metal oxides containing at least one transition metal or metal of the third main group, and transition metal complexes, preferably complexes of Cu, Co, Ni, Pd and Pt with ligands containing at least one oxygen atom as a bonding site. Further preferred are transition metal oxides as dopants, preferably oxides of rhenium, molybdenum and tungsten, more preferably Re2O7, MoO3, WO3 and ReO3. Further preferred are complexes of bismuth in the (III) oxidation state, more particularly bismuth (III) complexes with electron-deficient ligands, more particularly carboxylate ligands.

[0093] The p-type dopant is preferably substantially uniformly distributed in the p-type doped layer. For example, this can be achieved by co-evaporation of the p-type dopant and the hole transport material matrix. The p-type dopant is preferably present in the p-type doped layer in a proportion of 1% to 10%.

[0094] Preferred p-type dopants are especially the following compounds:

[0095]

[0096]

[0097] In a preferred embodiment of the present invention, the hole transport layer contains two different compounds according to formula (I).

[0098] The two different compounds of the same or different formula selected from the group consisting of formulae (I) and (II) are preferably each present in the hole transport layer in a proportion of at least 5%. They are more preferably present in a proportion of at least 10%. Preferably, one of the compounds is present in a higher proportion than the other compound, more preferably in a proportion of two to five times as high as the proportion of the other compound. This is especially true when the hole transport layer contains exactly two compounds of the same or different formula selected from the group consisting of formulae (I) and (II). Preferably, one of the compounds is present in the layer in a proportion of 15% to 35% and the other of the two compounds is present in the layer in a proportion of 65% to 85%.

[0099] Among formulae (I) and (II), preferred is formula (I).

[0100] Formula (I) and / or (II) is subject to one or more, preferably all, of the following preferences:

[0101] In a preferred embodiment, the compound has a single amino group. An amino group is understood to mean a group having a nitrogen atom with three binding partners. This is preferably understood to mean a group in which three groups selected from aromatic and heteroaromatic groups are bound to the nitrogen atom.

[0102] In an alternative preferred embodiment, the compound has exactly two amino groups.

[0103] Z is preferably CR 1 , among which When the group is bonded thereto, Z is C;

[0104] X is preferably a single bond;

[0105] Ar 1 is preferably the same or different at each occurrence and is selected from divalent radicals derived from benzene, biphenyl, terphenyl, naphthalene, fluorene, indenofluorene, indenocarbazole, spirobifluorene, dibenzofuran, dibenzothiophene and carbazole, each of which is replaced by one or more R 2 Most preferably, Ar 1 is the same or different on each occurrence and is a divalent radical derived from benzene, the divalent radical being replaced in each case by one or more R 2 Group substitution. 1 A radical may be identical or different on each occurrence.

[0106] The index n is preferably 0, 1 or 2, more preferably 0 or 1, most preferably 0. In the case of n=1, preferably -(Ar 1 ) n - The group conforms to the following formula:

[0107]

[0108]

[0109]

[0110]

[0111]

[0112] wherein the dashed line represents a bond to the rest of the formula, and wherein the groups at the positions shown as unsubstituted are each replaced by R 2 The R 2 The group is preferably H.

[0113] Ar 2 The radical is preferably identical or different on each occurrence and is selected from the group consisting of monovalent radicals derived from benzene, biphenyl, terphenyl, quaterphenyl, naphthalene, fluorene, especially 9,9'-dimethylfluorene and 9,9'-diphenylfluorene, 9-silafluorene, especially 9,9'-dimethyl-9-silafluorene and 9,9'-diphenyl-9-silafluorene, benzofluorene, spirobifluorene, indenofluorene, indenocarbazole, dibenzofuran, dibenzothiophene, benzocarbazole, carbazole, benzofuran, benzothiophene, indole, quinoline, pyridine, pyrimidine, pyrazine, pyridazine, and triazine; wherein the monovalent radicals are each substituted by one or more R 2 Alternatively, Ar 2 The radicals are identical or different at each occurrence and may preferably be selected from a combination of radicals derived from benzene, biphenyl, terphenyl, quaterphenyl, naphthalene, fluorene, especially 9,9'-dimethylfluorene and 9,9'-diphenylfluorene, 9-silafluorene, especially 9,9'-dimethyl-9-silafluorene and 9,9'-diphenyl-9-silafluorene, benzofluorene, spirobifluorene, indenofluorene, indenocarbazole, dibenzofuran, dibenzothiophene, carbazole, benzofuran, benzothiophene, indole, quinoline, pyridine, pyrimidine, pyrazine, pyridazine, and triazine; wherein each of the radicals is replaced by one or more R 2 Group substitution.

[0114] Ar 2The radical is identical or different at each occurrence and is selected from the group consisting of phenyl, biphenyl, terphenyl, quaterphenyl, naphthyl, fluorenyl, in particular 9,9'-dimethylfluorenyl and 9,9'-diphenylfluorenyl, benzofluorenyl, spirobifluorenyl, indenofluorenyl, indenocarbazolyl, dibenzofuranyl, dibenzothienyl, carbazolyl, benzofuranyl, benzothienyl, benzo-fused dibenzofuranyl, benzo-fused dibenzothienyl, naphthyl-substituted phenyl, fluorenyl-substituted phenyl, spirobifluorenyl-substituted phenyl, dibenzofuranyl-substituted phenyl, dibenzothienyl-substituted phenyl, carbazolyl-substituted phenyl, pyridyl-substituted phenyl, pyrimidyl-substituted phenyl, and triazinyl-substituted phenyl; wherein the radicals mentioned are each substituted by one or more R 2 Group substitution.

[0115] Ar 2 The groups are identical or different and are selected from the following formulae:

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133] Where the groups at the positions shown as unsubstituted are replaced by R 2 The R 2 Preferably it is H, and wherein the dashed bond is the bond to the nitrogen atom of the amino group.

[0134] Preferably, R 1 and R 2 is the same or different at each occurrence and is selected from: H, D, F, CN, Si (R 3 )3,N(R 3 )2, a straight-chain alkyl or alkoxy group having 1 to 20 carbon atoms, a branched or cyclic alkyl or alkoxy group having 3 to 20 carbon atoms, an aromatic ring system having 6 to 40 aromatic ring atoms, and a heteroaromatic ring system having 5 to 40 aromatic ring atoms; wherein the alkyl and alkoxy groups, the aromatic ring systems and the heteroaromatic ring systems mentioned are each replaced by R 3 and wherein one or more CH2 groups in the alkyl or alkoxy groups mentioned may be -C≡C-, R 3 C=CR 3 -、Si(R 3 )2. C=O, C=NR 3 、-NR 3 -, -O-, -S-, -C(=O)O- or -C(=O)NR 3 -replace.

[0135] More preferably, R 1 is the same or different at each occurrence and is selected from: H, D, F, CN, an aromatic ring system having 6 to 40 aromatic ring atoms, and a heteroaromatic ring system having 5 to 40 aromatic ring atoms; wherein the aromatic ring system and the heteroaromatic ring system mentioned are each replaced by R 3 Group substitution.

[0136] More preferably, R 2 is the same or different at each occurrence and is selected from: H, D, F, CN, Si (R 3 )4, a straight-chain alkyl group having 1 to 10 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, an aromatic ring system having 6 to 40 aromatic ring atoms, and a heteroaromatic ring system having 5 to 40 aromatic ring atoms; wherein the alkyl group, the aromatic ring system and the heteroaromatic ring system mentioned are each replaced by R 3 Group substitution.

[0137] Particularly preferred are:

[0138] -Z is CR 1 , among which When the group is bonded thereto, Z is C;

[0139] -X is a single bond;

[0140] -Ar 1 is identical or different on each occurrence and is a divalent radical derived from benzene, said divalent radical being replaced in each case by one or more R 2 Group substitution;

[0141] - the flag n is 0 or 1;

[0142] -Ar 2 is the same or different at each occurrence and is selected from the above formula Ar 2 -1 to Ar 2 -272;

[0143] -R 1 is the same or different at each occurrence and is selected from: H, D, F, CN, an aromatic ring system having 6 to 40 aromatic ring atoms, and a heteroaromatic ring system having 5 to 40 aromatic ring atoms; wherein the aromatic ring system and the heteroaromatic ring system mentioned are each replaced by R 3 Group substitution;

[0144] -R 2 is the same or different at each occurrence and is selected from: H, D, F, CN, Si (R 3 )4, a straight-chain alkyl group having 1 to 10 carbon atoms, a branched or cyclic alkyl group having 3 to 20 carbon atoms, an aromatic ring system having 6 to 40 aromatic ring atoms, and a heteroaromatic ring system having 5 to 40 aromatic ring atoms; wherein the alkyl group, the aromatic ring system and the heteroaromatic ring system mentioned are each replaced by R 3 Group substitution.

[0145] Formula (I) preferably conforms to formula (I-1)

[0146]

[0147] wherein the radicals occurring are as defined above and are preferably defined according to their preferred embodiments, and wherein the unoccupied positions on the spirobifluorene are replaced by R 1 Group substitution.

[0148] Formula (II) preferably conforms to formula (II-1)

[0149]

[0150] wherein the radicals occurring are as defined above and are preferably defined according to their preferred embodiments, and wherein the unoccupied positions on the fluorene are replaced by R 1 Group substitution.

[0151] Preferred embodiments of compounds of formula (I) are compounds cited as exemplary structures in WO2015 / 158411, WO2011 / 006574, WO2013 / 120577, WO2016 / 078738, WO2017 / 012687, WO2012 / 034627, WO2013 / 139431, WO2017 / 102063, WO2018 / 069167, WO2014 / 072017, WO2017 / 102064, WO2017 / 016632, WO2013 / 083216 and WO2017 / 133829.

[0152] Preferred embodiments of compounds of formula (II) are the compounds cited as exemplary structures in WO2014 / 015937, WO2014 / 015938, WO2014 / 015935 and WO2015 / 082056.

[0153] Hereinafter, one of the two different compounds in the hole transport layer that conform to the same or different formula selected from formula (I) and (II) is referred to as HTM-1, and the other of the two different compounds in the hole transport layer that conform to the same or different formula selected from formula (I) and (II) is referred to as HTM-2.

[0154] In a preferred embodiment, HTM-1 conforms to a formula selected from formula (I-1-A) and (II-1-A)

[0155]

[0156] and

[0157] HTM-2 conforms to the formula selected from formula (I-1-B), (I-1-C), (I-1-D), (II-1-B), (II-1-C) and (II-1-D)

[0158]

[0159]

[0160] wherein the radicals occurring in formulae (I-1-A) to (I-1-D) and (II-1-B) to (II-1-D) are as defined above and are preferably defined according to their preferred embodiments, and wherein the unoccupied positions on the spirobifluorene and fluorene are each replaced by R 1More preferably, HTM-2 conforms to formula (I-1-B) or (I-1-D), and most preferably conforms to formula (I-1-D). In an alternative preferred embodiment, HTM-2 conforms to formula (II-1-B) or (II-1-D), and most preferably conforms to formula (II-1-D).

[0161] Preferably, HTM-1 is present in the hole transport layer in a proportion that is five to two times higher than the proportion of HTM-2 in said layer.

[0162] Preferably, HTM-1 is present in the layer in a proportion of 50% to 95%, more preferably in a proportion of 60% to 90%, most preferably in a proportion of 65% to 85%.

[0163] Preferably, HTM-2 is present in the layer in a proportion of 5% to 50%, more preferably in a proportion of 10% to 40%, most preferably in a proportion of 15% to 35%.

[0164] Preferably, HTM-1 is present in the layer in a proportion of 65% to 85% and HTM-2 is present in the layer in a proportion of 15% to 35%.

[0165] In a preferred embodiment, the HOMO of HTM-1 is between -4.8 eV and -5.2 eV, and the HOMO of HTM-2 is between -5.1 eV and -5.4 eV. More preferably, the HOMO of HTM-1 is between -5.0 eV and -5.2 eV, and the HOMO of HTM-2 is between -5.1 eV and -5.3 eV. It is also preferred that the HOMO of HTM-1 is higher than that of HTM-2. More preferably, the HOMO of HTM-1 is 0.02 eV to 0.3 eV higher than that of HTM-2. "Higher HOMO" is understood herein to mean that the value in eV is less negative.

[0166] The HOMO level is determined by cyclic voltammetry (CV) by the method described on page 28, line 1 to page 29, line 21 of published specification WO 2011 / 032624.

[0167] The following table shows preferred embodiments of compound HTM-1:

[0168]

[0169]

[0170] The following table shows preferred embodiments of compound HTM-2:

[0171]

[0172]

[0173]

[0174]

[0175] The hole injection layer of the electronic device preferably directly adjoins the anode. It is also preferred that it directly adjoins the hole transport layer on the anode side. More preferably, the electronic device has a layer sequence of anode / hole injection layer / hole transport layer / luminescent layer, wherein the layers mentioned directly adjoin one another.

[0176] The thickness of the hole injection layer is preferably 2 nm to 50 nm, more preferably 2 nm to 30 nm. The thickness is preferably not more than 50 nm, more preferably not more than 30 nm.

[0177] In a preferred embodiment, the hole injection layer contains a mixture of a p-type dopant and a hole transport material as described above. The p-type dopant is preferably present in the hole injection layer in a proportion of 1% to 10%. The hole transport material is preferably selected from the material classes of hole transport materials for OLEDs known to those skilled in the art, especially triarylamines. Particularly preferred are indenofluoreneamine derivatives, amine derivatives, amine derivatives with fused aromatic systems, monobenzoindenofluoreneamines, dibenzoindenofluoreneamines, spirobifluoreneamines, fluoreneamines, spirodibenzopyranamines, dihydroacridine derivatives, spirodibenzofurans and spirodibenzothiophenes, phenanthryldiarylamines, spirotribenzotropolones, spirobifluorenes with metaphenyldiamine groups, spirobiacridines, xanthenediarylamines and 9,10-dihydroanthracene spirocyclic compounds with diarylamino groups.

[0178] The following table shows preferred specific compounds for use as hole transport materials in the hole injection layer:

[0179]

[0180]

[0181]

[0182]

[0183]

[0184]

[0185]

[0186]

[0187]

[0188]

[0189]

[0190]

[0191]

[0192] The above compounds H-1 to H-146 are not only suitable for use in hole injection layers, but are also generally suitable for use in layers having hole transport functions, such as hole injection layers, hole transport layers and / or electron blocking layers, or are suitable for use as matrix materials in light-emitting layers, especially as matrix materials in light-emitting layers containing one or more phosphorescent emitters.

[0193] Compounds H-1 to H-146 are generally well suited for the above-mentioned use in OLEDs of any design and composition, not just in the OLEDs of the present application. These compounds show good performance data in OLEDs, in particular good lifetime and good efficiency.

[0194] The hole transport material of the hole injection layer is more preferably selected from spirobifluorenylamine and fluorenylamine, more preferably selected from spirobifluorenylmonoamine and fluorenylmonoamine. Monoamine is understood here to refer to a compound containing a single amino group. Most preferably, the hole transport material of the hole injection layer is selected from the compounds of formula (I-1-A) and (II-1-A) defined above, more preferably selected from the compound of formula (I-1-A).

[0195] In an alternative preferred embodiment, the hole injection layer contains a hexaazaterphenylidene derivative, preferably as described in US 2007 / 0092755, or other highly electron-deficient and / or Lewis-acidic compounds, in each case in pure form, i.e. not mixed with other compounds. Examples of such compounds include bismuth complexes, in particular Bi(III) complexes, in particular Bi(III) carboxylates, such as the above-mentioned compound D-13.

[0196] In addition to the cathode, anode, light-emitting layer, hole injection layer and hole transport layer, the electronic device preferably further comprises other layers. These layers are preferably selected from one or more hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers, intermediate layers, charge generation layers and / or organic or inorganic layer p / n junctions in each case. However, it should be noted that each of these layers does not necessarily need to be present. More particularly, it is preferred that the electronic device comprises one or more layers selected from electron transport layers and electron injection layers, and the electron transport layers and electron injection layers are arranged between the light-emitting layer and the anode. More preferably, the electronic device comprises one or more electron transport layers, preferably a single electron transport layer and a single electron injection layer in sequence between the light-emitting layer and the cathode, wherein the electron injection layer mentioned is preferably directly adjacent to the cathode.

[0197] The layer sequence in the electronic component is preferably as follows:

[0198] -anode-

[0199] -Hole injection layer-

[0200] -Hole transport layer-

[0201] -Luminous layer-

[0202] -Optional hole blocking layer-

[0203] -Electron transport layer-

[0204] -Electron injection layer-

[0205] -cathode-.

[0206] Suitable materials for the hole blocking layer, electron transport layer and electron injection layer of the electronic device are, in particular, aluminum complexes, such as Alq3, zirconium complexes, such as Zrq4, lithium complexes, such as Liq, 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. The following table shows examples of specific compounds used in these layers:

[0207]

[0208]

[0209]

[0210] In a preferred embodiment, the electronic device is characterized in that one or more layers are applied by a sublimation process. In this case, the sublimation is carried out in a vacuum sublimation system at a temperature of less than 10 -5mbar, preferably less than 10 -6 The material is applied by vapor deposition at an initial pressure of 10 mbar. However, in this case, the initial pressure can also be even lower, for example less than 10 -7 millibar.

[0211] Likewise preferred is an electronic device as described below, characterized in that one or more layers are applied by the OVPD (organic vapor phase deposition) method or by means of carrier gas sublimation. In this case, at 10 -5 The material is applied at a pressure between mbar and 1 bar. A special case of this method is the OVJP (Organic Vapor Jet) method, in which the material is applied directly through a nozzle and thereby structured (eg MS Arnold et al., Appl. Phys. Lett. 2008, 92, 053301).

[0212] Furthermore preferred is an electronic device as described below, characterized in that one or more layers are produced from solution, for example by spin coating, or by any printing method such as screen printing, flexographic printing, nozzle printing or offset printing, but more preferably LITI (light-induced thermal imaging, thermal transfer) or inkjet printing. For this purpose, soluble compounds are required. High solubility can be obtained by appropriate substitution of the compounds.

[0213] It is also preferred to produce the electronic device according to the invention by applying one or more layers from solution and by applying one or more layers by sublimation methods.

[0214] After the layers have been applied (depending on the application), the component is structured, contact connections are provided and finally sealed in order to exclude the damaging effects of water and air.

[0215] The electronic device according to the invention is preferably used in displays, as a light source in lighting applications or as a light source in medical and / or cosmetic applications. Example

[0216] 1) General OLED manufacturing methods and OLED characterization

[0217] A glass plate coated with structured ITO (indium tin oxide) with a thickness of 50 nm is the substrate to which the OLED is to be applied.

[0218] An OLED essentially has the following layer structure: substrate / hole injection layer (HIL) / hole transport layer (HTL) / emissive layer (EML) / electron transport layer (ETL) / 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 an OLED can be found in Table 1.

[0219] All materials are applied by thermal vapor deposition in a vacuum chamber. In the present embodiment, the light-emitting layer here consists of a matrix material (host material) and a luminescent dopant (luminophore), which is added to the matrix material in a specific volume ratio by co-evaporation. A detail given in the form of SMB1:SEB1 (5%) means here that the material SMB1 is present in the layer in a volume proportion of 95% and the material SEB1 in a volume proportion of 5%. Similarly, the electron transport layer and in specific embodiments the HIL and / or HTL also consist of a mixture of two materials, wherein the ratios of the materials are reported as specified above.

[0220] The chemical structures of the materials used for OLEDs are shown in Table 2.

[0221] The OLEDs were characterized in a standard manner. For this purpose, the electroluminescence spectrum, the external quantum efficiency (EQE, measured in %), calculated as a function of the brightness from the current-voltage-brightness characteristics assuming Lambertian luminescence characteristics, and the lifetime were determined. Parameter EQE@10 mA / cm 2 Refers to 10mA / cm 2 The external quantum efficiency achieved under the condition of . Parameter U@10mA / cm 2 Refers to 10mA / cm 2 The lifetime LT is defined as the time for the brightness to drop from the starting brightness to a certain proportion during operation at a constant current density. The LT80 figure here means that the reported lifetime corresponds to the time for the brightness to drop to 80% of its starting value. Figures @ 60mA / cm 2 This means that the lifetime in question is at 60 mA / cm 2 Measured below.

[0222] 2) OLEDs using a mixture of two different materials in the HTL and a comparative example using a single material in the HTL together with a doped HIL

[0223] The following OLEDs were manufactured:

[0224]

[0225] This gives the following measurements:

[0226]

[0227] By adding the compound HTM5 to the HTL containing HTM3, a significantly improved efficiency is obtained in the OLED E1 at the same voltage. A comparison is made here with the OLED V1 which contains only the compound HTM3 in the HTL and is otherwise identical in construction.

[0228] A clear improvement in efficiency was also found when compound HTM6 was added to the HTL containing HTM2 (OLED E2). Comparison was made here with OLED V2, which contained only compound HTM2 in the HTL and was otherwise identical in construction.

[0229] Although the efficiency improvements are small in percentage terms, they are not negligible because efficiency improvements are difficult to achieve.

[0230] 3) OLEDs using a mixture of two different materials in the HTL and a comparative example using a single material in the HTL together with a HIL consisting of a single material

[0231] The following OLEDs were manufactured:

[0232]

[0233] This gives the following measurements:

[0234]

[0235] By adding the compounds HTM5 (E3) or HTM6 (E4) to the HTL containing the compound HTM1, the lifetime was improved in each case. A comparison is made here with OLED V3, which contains only the compound HTM1 in the HTL and is otherwise identical in construction.

[0236] Compared to the thicker HTL used in OLEDs V3, E3 and E4, the lifetime is also improved in the case of OLEDs with a thinner HTL (70 nm), as shown in the following examples. As before, OLEDs with a mixture of two different materials in the HTL (E6, E7 and E8) are compared here with an OLED containing only compound HTM1 in the HTL (V4).

[0237]

[0238] This gives the following measurements:

[0239]

[0240] In all cases, the addition of a material selected from HTM5, HTM6 and HTM7 improves the lifetime of the OLED.

[0241] The second material may also be added in a higher proportion than the above 20%, as shown in the following examples:

[0242]

[0243] The following results are obtained:

[0244]

[0245]

[0246] However, adding the second material in a high proportion has the disadvantage of causing efficiency loss. When the second material is used in a proportion of 10% to 30% by volume, especially 20% by volume as shown above, even if there is such a disadvantage, the degree of occurrence is significantly lower.

[0247]

[0248] 4) Determination of HOMO of compounds used in mixed HTL

[0249] The method described in the published specification WO 2011 / 032624, page 28, line 1 to page 29, line 21, gives the following HOMO values ​​for compounds HTM1, HTM2, HTM3, HTM5, HTM6 and HTM7:

[0250] Compound HOMO(eV) HTM1 -5.15 HTM2 -5.18 HTM3 -5.15 HTM5 -5.27 HTM6 -5.23 HTM7 -5.26

Claims

1. An electronic device, comprising -anode, -cathode, - a light-emitting layer arranged between the anode and the cathode, - a hole injection layer arranged between the anode and the light-emitting layer; a hole transport layer which is arranged between the hole injection layer and the light-emitting layer and directly adjoins the light-emitting layer on the anode side of the light-emitting layer and directly adjoins the hole injection layer on the cathode side of the hole injection layer, and the hole transport layer contains two different compounds which conform to the same or different formulae selected from formulae (I) and (II) in Z is the same or different in each occurrence and is selected from CR 1 and N, where When the group is bonded to Z, Z is C; X is the same or different at each occurrence and is selected from a single bond, O, S, C(R 1 )2 and NR 1 ; Ar 1 and Ar 2 are the same or different at each occurrence and are selected from a group consisting of a group having 6 to 40 aromatic ring atoms and surrounded by one or more R 2 Aromatic ring systems substituted with a radical and having 5 to 40 aromatic ring atoms and substituted with one or more R 2 Group-substituted heteroaromatic ring systems; R 1 is the same or different at each occurrence and is selected from: H, D, F, Cl, Br, I, C(=O)R 3 ,CN,Si(R 3 )3,N(R 3 )2,P(=O)(R 3 )2,OR 3 , S(=O)R 3 , S(=O)2R 3 , straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherein two or more R 1 The radicals may be linked to one another and may form a ring; wherein the alkyl, alkoxy, alkenyl and alkynyl radicals mentioned and the aromatic and heteroaromatic ring systems mentioned are each replaced by R 3 and wherein the alkyl, alkoxy, alkenyl and alkynyl groups mentioned in one or more CH2 groups can be -R 3 C=CR 3 -、-C≡C-、Si(R 3 )2. C=O, C=NR 3 、-C(=O)O-、-C(=O)NR 3 -、NR 3 ,P(=O)(R 3 ), -O-, -S-, SO or SO2; R 2 is the same or different at each occurrence and is selected from: H, D, F, Cl, Br, I, C(=O)R 3 ,CN,Si(R 3 )3,P(=O)(R 3 )2,OR 3 , S(=O)R 3 , S(=O)2R 3 , straight-chain alkyl or alkoxy groups having 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 carbon atoms, alkenyl or alkynyl groups having 2 to 20 carbon atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; wherein two or more R 1 or R 2 The radicals may be linked to one another and may form a ring; wherein the alkyl, alkoxy, alkenyl and alkynyl radicals mentioned and the aromatic and heteroaromatic ring systems mentioned are each replaced by R 3 and wherein the alkyl, alkoxy, alkenyl and alkynyl groups mentioned in one or more CH2 groups can be -R 3 C=CR 3 -、-C≡C-、Si(R 3 )2. C=O, C=NR 3 、-C(=O)O-、-C(=O)NR 3 -、P(=O)(R 3 ), -O-, -S-, SO or SO2; R 3 is the same or different at each occurrence and is selected from: H, D, F, Cl, Br, I, CN, an alkyl or alkoxy group having 1 to 20 carbon atoms, an alkenyl or alkynyl group having 2 to 20 carbon atoms, an aromatic ring system having 6 to 40 aromatic ring atoms, and a heteroaromatic ring system having 5 to 40 aromatic ring atoms; wherein two or more R 3 The groups may be connected to each other and may form a ring; and the alkyl groups, alkoxy groups, alkenyl groups and alkynyl groups, aromatic ring systems and heteroaromatic ring systems mentioned therein may be substituted by one or more groups selected from F and CN; n is 0, 1, 2, 3 or 4, wherein, When n = 0, Ar 1 The group is absent and the nitrogen atom is directly bonded to the remainder of the formula; and The hole transport layer has a layer thickness of 20 nm to 300 nm.

2. The electronic device according to claim 1, characterized in that The light-emitting layer is a light-emitting layer that emits blue fluorescence or a light-emitting layer that emits green phosphorescence.

3. The electronic device according to claim 1, characterized in that The layer thickness of the hole transport layer is not more than 250 nm.

4. The electronic device according to claim 1, characterized in that The hole transport layer contains exactly two different compounds of the same or different formulae selected from formulae (I) and (II).

5. The electronic device according to claim 1, characterized in that The hole transport layer is composed of compounds conforming to the same or different formulae selected from formulae (I) and (II).

6. The electronic device according to claim 1, characterized in that The hole transport layer contains two different compounds according to formula (I).

7. The electronic device according to claim 1, characterized in that The two different compounds which conform to the same or different formulae selected from the group consisting of formulae (I) and (II) are each present in the hole transport layer in a proportion of at least 5%.

8. The electronic device according to claim 1, characterized in that One of the two different compounds in the hole transport layer is a compound HTM-1 selected from the group consisting of formula (I-1-A) and (II-1-A) And the other of the two different compounds in the hole transport layer is a compound HTM-2 selected from the group consisting of formula (I-1-B), (I-1-C), (I-1-D), (II-1-B), (II-1-C) and (II-1-D) wherein the groups appearing in formulae (I-1-A) to (I-1-D) and (II-1-B) to (II-1-D) are the same as those defined in claim 1, and wherein the unoccupied positions on the spirobifluorene and fluorene are each replaced by R 1 Group substitution.

9. The electronic device according to claim 8, characterized in that The proportion of HTM-1 in the hole transport layer is five to two times higher than the proportion of HTM-2 in the hole transport layer.

10. The electronic device according to claim 8, characterized in that HTM-1 is present in the hole transport layer in a proportion of 65% to 85%, and HTM-2 is present in the hole transport layer in a proportion of 15% to 35%.

11. The electronic device according to claim 8, characterized in that The HOMO of HTM-1 is -4.8 eV to -5.2 eV, and the HOMO of HTM-2 is -5.1 eV to -5.4 eV.

12. The electronic device according to claim 8, characterized in that The HOMO of HTM-1 is 0.02 eV to 0.3 eV higher than that of HTM-2.

13. The electronic device according to claim 1, characterized in that The electronic component has a layer sequence of anode / hole-injection layer / hole-transport layer / emitting layer, the layers mentioned directly adjoining one another.

14. The electronic device according to claim 1, characterized in that The hole injection layer contains a mixture of a p-type dopant and a hole transport material.

15. The electronic device according to claim 1, characterized in that The hole transport material of the hole injection layer is selected from the compounds of formula (I-1-A) and (II-1-A) defined above, wherein the groups appearing in formula (I-1-A) and (II-1-A) are the same as those defined in claim 1, and wherein the unoccupied positions on the spirobifluorene and fluorene are each replaced by R 1 Group substitution.

16. The electronic device according to claim 15, characterized in that The hole transport material of the hole injection layer is selected from the compounds of formula (I-1-A).

17. The electronic device according to any one of claims 1 to 16, characterized in that The hole injection layer contains a hexaazaterphenylidene derivative or other highly electron-deficient and / or Lewis-acidic compound, each in pure form.

18. A method for manufacturing an electronic device according to any one of claims 1 to 16, characterized in that One or more layers of the device are produced from solution or by a sublimation process.

19. Use of an electronic device according to any one of claims 1 to 16 in a display, as a light source in lighting applications or as a light source in medical and / or cosmetic applications.

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