Electronic devices

Abstract

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

Description

[0001] The present application relates to an electronic device, which comprises an anode, a first hole transport layer, a second hole transport layer, a light-emitting layer and a cathode in sequence. The first hole transport layer contains a mixture of two different compounds.

[0002] Electronic devices in the sense of the present 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 are electronic devices that have one or more layers containing organic compounds and emit light when a voltage is applied. The construction and general functional principles of OLEDs are known to those skilled in the art.

[0003] 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, in an OLED comprising a light-emitting layer, is arranged between the anode and the light-emitting layer.

[0004] In electronic devices, especially OLEDs, there is a great deal of interest in improving performance data, in particular lifetime, efficiency, operating voltage and color purity. No completely satisfactory solutions have yet been found in these areas.

[0005] Hole transport layers significantly influence the aforementioned performance characteristics of electronic devices. They can be present as a single hole transport layer between the anode and the light-emitting layer, or as multiple hole transport layers, for example, two or three, between the anode and the light-emitting layer. In addition to their hole-transporting function, hole transport layers can also have an electron-blocking function, meaning they block the passage of electrons from the light-emitting layer to the anode. This function is particularly desirable in hole transport layers that directly adjoin the light-emitting layer on the anode side.

[0006] Hole transport layer materials known in the prior art are primarily amine compounds, particularly triarylamine compounds. Examples of such triarylamine compounds include spirobifluorenamine, fluorenamine, indenofluorenamine, phenanthrenamine, carbazoleamine, xantheneamine, spirodihydroacridinamine, benzidine, and combinations thereof having one or more amino groups. This is merely one selection, and those skilled in the art will appreciate other structural classes.

[0007] Surprisingly, it has now been found that electronic devices comprising an anode, a cathode, a light-emitting layer, a first hole-transport layer, and a second hole-transport layer, wherein the first hole-transport layer comprises a mixture of two different compounds, have better performance data than prior art electronic devices in which the first hole-transport layer is formed from a single compound. More particularly, the lifetime of such devices is improved compared to the aforementioned prior art devices.

[0008] The present application thus provides an electronic device comprising

[0009] -anode,

[0010] -cathode,

[0011] - a light-emitting layer arranged between the anode and the cathode,

[0012] - a first hole transport layer arranged between the anode and the light-emitting layer, which contains two different compounds of the same or different formulae selected from formulae (I) and (II)

[0013]

[0014] in

[0015] Z is the same or different at each occurrence and is selected from CR 1 and N, where When the group is bonded to Z, Z is C;

[0016] 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 ;

[0017] 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 An aromatic ring system 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;

[0018] 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 2The 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;

[0019] R 3 are the same or different at each occurrence and are 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 one another 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;

[0020] 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;

[0021] as well as

[0022] - a second hole transport layer arranged between the first hole transport layer and the light emitting layer.

[0023] 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 -Ar 1 -Ar 1 -Ar 1 -. When n=4, four Ar 1 The groups are successfully bonded continuously, which is -Ar 1 -Ar 1 -Ar 1 -Ar 1 -.

[0024] The following definitions are applicable to chemical groups used in this application. Unless any more specific definition is given, they are applicable.

[0025] Aryl groups in the context of the present invention are understood to mean single aromatic rings, i.e. benzene, or fused aromatic polycyclic rings, such as naphthalene, phenanthrene or anthracene. Fused aromatic polycyclic rings in the context of the present application are composed of two or more single aromatic rings fused to each other. Fusion between the rings is understood here to mean that the rings share at least one edge. Aryl groups in the context of the present invention contain 6 to 40 aromatic ring atoms. Aryl groups do not contain any heteroatoms as aromatic ring atoms.

[0026] 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 ring, such as quinoline or carbazole. The fused heteroaromatic polycyclic ring 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 mean that the rings share at least one edge 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.

[0027] Aryl or heteroaryl radicals, which may each be substituted by the above-mentioned radicals, are understood in particular to mean radicals derived from benzene, naphthalene, anthracene, phenanthrene, pyrene, dihydropyrene, chrysene, 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, benzothiophene, benzothiophene, benzothiophene, benzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenanthroline, benzothiophene ... Azine, pyrazole, indazole, imidazole, benzimidazole, benzimidazole [1,2-a] benzimidazole, naphthimidazole, phenanthimidazole, pyridimidazole, pyrazinimidazole, quinoxalinimidazole, Azoles, benzophenones Azoles, naphtho Azoles, anthracenes azole, phenanthroline Azoles, isocyanates azole, 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.

[0028] The aromatic ring system in the context of the present invention is not necessarily a system containing only a single 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 systems 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.

[0029] A heteroaromatic ring system meets the above definition of an aromatic ring system, except that it must contain at least one heteroatom as a ring atom. As with aromatic ring systems, heteroaromatic ring systems do not necessarily contain only aryl 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 single bonds, such as 4,6-diphenyl-2-triazinyl. A 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.

[0030] Thus, the terms "heteroaromatic ring system" and "aromatic ring system" as defined in this application differ from one another 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.

[0031] According to the above definitions, any aryl group is encompassed by the term "aromatic ring system" and any heteroaryl group is encompassed by the term "heteroaromatic ring system".

[0032] An aromatic ring system having 6 to 40 aromatic ring atoms or a heteroaromatic ring system having 5 to 40 aromatic ring atoms is understood as meaning, in particular, 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.

[0033] In the context of the present invention, straight-chain alkyl groups having 1 to 20 carbon atoms, and branched or cyclic alkyl groups having 3 to 20 carbon atoms, and alkenyl or alkynyl groups 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 as meaning methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl 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.

[0034] 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 to mean 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 said group comprises: a) an 1,2,3,4-difluorothio group, b) an 1,2,4-difluorothio group, c) an 1,2,4-difluorothio group, and c) an 1,2,4-difluorothio group. The group may be any of the following: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 67, 68, 69, 71, 72, 73, 74, 75, 76, 77, 78, 79, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100

[0035] 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 linked to one another by a chemical bond. However, the 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.

[0036] The electronic device is preferably an organic electroluminescent device (OLED).

[0037] Preferred anodes for the electronic device 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 in order to enable illumination of the organic material (organic solar cells) or emission of light (OLEDs, O-lasers). Preferred anode materials in this case are conductive mixed metal oxides. Particularly preferred are indium tin oxide (ITO) or indium zinc oxide (IZO). Furthermore, preferred are conductive doped organic materials, in particular conductive doped polymers. Alternatively, the anode may consist of two or more layers, for example an inner layer of ITO and an outer layer of a metal oxide, preferably tungsten oxide, molybdenum oxide or vanadium oxide.

[0038] The preferred cathode of the electronic device is a metal, metal alloy or multilayer structure with a low work function, and the metal alloy or multilayer structure is composed of various 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 metal mentioned, other metals with a relatively high work function can also be used, such as Ag or Al, in which case a combination of 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 0.5 nm and 5 nm.

[0039] 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 particularly preferably a light-emitting layer that emits blue fluorescence. In the fluorescent light-emitting layer, the light emitter is preferably a singlet light emitter, i.e., 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, i.e., 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.

[0040] In a preferred embodiment, the fluorescent emitting layer used is a blue-fluorescing layer.

[0041] In a preferred embodiment, the phosphorescent emitting layer used is a green or red phosphorescent emitting layer.

[0042] 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 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.

[0043] In general, all phosphorescent complexes which are used according to the prior art for phosphorescent OLEDs and are known to those skilled in the art in the field of organic electroluminescent devices are suitable for use in the devices according to the invention.

[0044] The following table shows preferred compounds for use as phosphorescent emitters:

[0045]

[0046]

[0047]

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056] Preferred fluorescent emitting compounds are selected from the class of arylamines. In the context of the present invention, arylamines or aromatic amines 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. Preferred examples are aromatic anthraceneamines, aromatic anthracenediamines, aromatic pyreneamines, aromatic pyrenediamines, aromatic leucamines, or aromatic leucamines. Aromatic anthraceneamines are understood to mean compounds in which one diarylamino group is directly bonded to an anthracene group, preferably at the 9-position. Aromatic anthracenediamines are understood to mean compounds in which two diarylamino groups are directly bonded to an anthracene group, preferably at the 9- and 10-positions. The definitions of aromatic pyreneamines, pyrenediamines, leucamines, and leucamines are similar, with the diarylamino groups preferably being bonded to the pyrene at the 1-position or at the 1,6-positions. Other preferred luminescent compounds are indenofluorenamine or indenofluorenediamine, benzoindenofluorenamine or benzoindenofluorenediamine, and dibenzoindenofluorenamine or dibenzoindenofluorenediamine, as well as indenofluorene derivatives with fused aryl groups. Also preferred are pyrenarylamines. Also preferred are benzoindenofluorenamine, benzofluorenamine, extended benzoindenofluorene, phenanthene ... Oxazine, and fluorene derivatives linked 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]

[0066] In a preferred embodiment, the light-emitting layer of the electronic device contains exactly one host compound. A host compound is understood to be a compound that is not a light-emitting compound. This embodiment is particularly preferred in the case of fluorescent light-emitting layers.

[0067] 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 known as a mixed-matrix system, is particularly preferred in the case of phosphorescent light-emitting layers.

[0068] 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%.

[0069] 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.

[0070] 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%.

[0071] 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%.

[0072] Accordingly, the proportion of the fluorescent compound is between 0.1% and 50.0%, more preferably between 0.5% and 20.0%, and most preferably between 1.0% and 10.0%.

[0073] The mixed matrix system preferably comprises two or three different host materials, more preferably two different host materials. Preferably, in this case, one of the two materials is a material having a property including hole transport properties, and the other material is a material having a property including electron transport properties. Other host 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 host 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.

[0074] Preferred matrix materials for fluorescent compounds are selected from the following classes: oligoarylidenes (e.g. 2,2',7,7'-tetraphenylspirobifluorene), in particular oligoarylidenes containing fused aromatic groups, oligoarylidene vinylidene, 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: oligoarylidenes containing naphthalene, anthracene, benzanthracene and / or pyrene or atropisomers of these compounds, oligoarylidene vinylidene, ketones, phosphine oxides, and sulfoxides. Very particularly preferred matrix materials are selected from the following classes: oligoarylidenes containing anthracene, benzanthracene, triphenylene and / or pyrene or atropisomers of these compounds. In the context of the present invention, oligoarylidenes are understood to be compounds in which at least three aryl or arylidene groups are bonded to one another.

[0075] The following table shows preferred host materials for fluorescent light-emitting compounds:

[0076]

[0077]

[0078]

[0079]

[0080] 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, borazolidines or boric esters, triazine derivatives, zinc complexes, siladiazacyclopentazone or siladiazacyclopentazone derivatives, phosphadiazacyclopentazone derivatives, bridged carbazole derivatives, terphenylidene derivatives or lactams.

[0081] In a preferred embodiment, the electronic device contains exactly one light-emitting layer.

[0082] In an alternative preferred embodiment, the electronic device comprises a plurality of light-emitting layers, preferably 2, 3 or 4 light-emitting layers. This is particularly preferred for white light-emitting electronic devices.

[0083] More preferably, in this case, the emitting layer as a whole has multiple emission peaks between 380 nm and 750 nm, so that the electronic device emits white light; in other words, multiple emitting compounds that can fluoresce or phosphoresce and emit blue, green, yellow, orange, or red light are used in the emitting layer. Particularly preferred are three-layer systems, i.e., systems with three emitting layers, in which in each case one of the three layers emits blue light, in each case one of the three layers emits green light, and in each case one of the three layers emits orange or red light. To generate white light, a single emitter compound that emits across a broad wavelength range can also be used, rather than multiple emitter compounds that emit colored light.

[0084] In a preferred embodiment of the present invention, the electronic device comprises two or three, preferably three identical or different, layer sequences stacked one on top of the other, wherein each layer sequence comprises the following layers: a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer and an electron transport layer, and wherein at least one, preferably all, layer sequences comprise the following layers:

[0085] - a light-emitting layer arranged between the anode and the cathode,

[0086] a first hole-transport layer arranged between the anode and the light-emitting layer, which contains two different compounds of the same or different formulae selected from formulae (I) and (II),

[0087] and

[0088] - a second hole transport layer arranged between the first hole transport layer and the light emitting layer.

[0089] Preferably, a double layer consisting of adjacent n-CGL and p-CGL is arranged between the layer sequences, with the n-CGL being arranged on the anode side and the p-CGL being arranged on the cathode side. "CGL" here refers to the charge generation layer. Materials for such layers are known to those skilled in the art. P-doped amines are preferably used in the p-CGL, more preferably materials selected from the preferred structural classes of hole-transporting materials mentioned below.

[0090] The thickness of the first hole transport layer is preferably 20 nm to 300 nm, more preferably 30 nm to 250 nm, and further preferably no greater than 250 nm.

[0091] Preferably, the first 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).

[0092] Preferably, the first hole transport layer is composed of a compound that conforms to the same or different formulae selected from formulae (I) and (II). "Composed of..." is understood herein to mean that no other compounds are present in the layer, and small amounts of impurities typically present during the production of OLEDs are not counted as other compounds in the layer.

[0093] In an alternative preferred embodiment, it contains, in addition to the compound corresponding to the same or different formula selected from formulae (I) and (II), a p-type dopant.

[0094] 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.

[0095] Particularly preferred p-type dopants are quinodimethane compounds, azaindenofluorenediones, azapines, azaterphenylidenes, I2, metal halides, preferably transition metal halides, metal oxides, preferably metal oxides containing at least one transition metal or Group 3 metal, 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. Even more preferred are bismuth(III) complexes in the oxidation state, more particularly bismuth(III) complexes with electron-deficient ligands, more particularly carboxylate ligands.

[0096] The p-type dopant is preferably substantially uniformly distributed in the p-type doped layer. This can be achieved, for example, 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%.

[0097] Preferred p-type dopants are especially the following compounds:

[0098]

[0099]

[0100] In a preferred embodiment of the present invention, the first hole transport layer contains two different compounds conforming to formula (I).

[0101] The two different compounds, which correspond to the same or different formulas selected from the group consisting of formulae (I) and (II), are preferably each present in the first 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 that is two to five times greater than the proportion of the other compound. This is particularly true when the first hole transport layer contains exactly two compounds, which correspond to the same or different formulas selected from the group consisting of formulae (I) and (II). Preferably, the proportion of one of the compounds in the layer is from 15% to 35%, and the proportion of the other of the two compounds in the layer is from 65% to 85%.

[0102] Among formulae (I) and (II), preferred is formula (I).

[0103] Formula (I) and / or (II) is subject to one or more, preferably all, preferences selected from the following preferences:

[0104] 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.

[0105] In an alternative preferred embodiment, the compound has exactly two amino groups.

[0106] Z is preferably CR 1 , among which When the group is bonded to Z, Z is C;

[0107] X is preferably a single bond;

[0108] 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 at 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. 1 A group may be identical or different on each occurrence.

[0109] The index n is preferably 0, 1 or 2, more preferably 0 or 1, most preferably 0.

[0110] Preferred -(Ar 1 ) n - group conforms to the following formula when n=1:

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118] wherein the dashed line represents a bond to the rest of the formula, and wherein the groups are each replaced by R at the positions shown as unsubstituted 2 Group substitution, wherein R 2 The group is preferably H.

[0119] 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, in particular 9,9'-dimethylfluorene and 9,9'-diphenylfluorene, 9-silafluorene, in particular 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 replaced 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, in particular 9,9'-dimethylfluorene and 9,9'-diphenylfluorene, 9-silafluorene, in particular 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.

[0120] Particularly preferred is 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, dibenzothiophenyl, carbazolyl, benzofuranyl, benzothiophenyl, benzo-fused dibenzofuranyl, benzo-fused dibenzothiophenyl, naphthyl-substituted phenyl, fluorenyl-substituted phenyl, spirobifluorenyl-substituted phenyl, dibenzofuranyl-substituted phenyl, dibenzothiophenyl-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.

[0121] Particularly preferred is Ar 2 The groups are identical or different and are selected from the following formulae:

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142]

[0143]

[0144] wherein the group is replaced at the position shown as unsubstituted by R 2 Group substitution, wherein R 2 Preferably it is H, and wherein the dashed bond is the bond to the amine nitrogen atom.

[0145] Preferably, R 1 and R 2 are the same or different at each occurrence and are selected from: H, D, F, CN, Si(R 3 )3,N(R 3 )2, a linear 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.

[0146] 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.

[0147] More preferably, R 2 are the same or different at each occurrence and are 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.

[0148] Particularly preferred are:

[0149] -Z is CR 1 , among which When the group is bonded to Z, Z is C;

[0150] -X is a single bond;

[0151] -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;

[0152] - the flag n is 0 or 1;

[0153] -Ar 2 is the same or different at each occurrence and is selected from the above formula Ar 2 -1 to Ar 2 -272;

[0154] -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;

[0155] -R 2 are the same or different at each occurrence and are 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.

[0156] Formula (I) preferably conforms to formula (I-1)

[0157]

[0158] wherein the groups 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.

[0159] Formula (II) preferably conforms to formula (II-1)

[0160]

[0161]

[0162] wherein the groups occurring are as defined above and preferably defined according to their preferred embodiments, and wherein the unoccupied positions on the fluorene are replaced by R 1 Group substitution.

[0163] Preferred embodiments of the compounds of formula (I) are the 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.

[0164] Preferred embodiments of compounds of formula (II) are the compounds cited as exemplary structures in WO2014 / 015937, WO2014 / 015938, WO2014 / 015935 and WO2015 / 082056.

[0165] Hereinafter, one of the two different compounds that conform to the same or different formulas selected from formula (I) and (II) in the first hole transport layer is referred to as HTM-1, and the other of the two different compounds that conform to the same or different formulas selected from formula (I) and (II) in the first hole transport layer is referred to as HTM-2.

[0166] In a preferred embodiment, HTM-1 conforms to a formula selected from formula (I-1-A) and (II-1-A)

[0167]

[0168] and

[0169] HTM-2 conforms to a formula selected from formula (I-1-B), (I-1-C), (I-1-D), (II-1-B), (II-1-C) and (II-1-D)

[0170]

[0171] wherein the radicals occurring in formulae (I-1-A) to (I-1-D) and (II-1-A) 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 1 More 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).

[0172] Preferably, HTM-1 is present in the first hole transport layer in a proportion that is five to two times higher than the proportion of HTM-2 in said layer.

[0173] 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%.

[0174] 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%.

[0175] 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%.

[0176] 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.

[0177] The HOMO level was determined by cyclic voltammetry (CV) using the method described on page 28, line 1 to page 29, line 21 of published specification WO 2011 / 032624.

[0178] The following table shows preferred embodiments of compound HTM-1:

[0179]

[0180]

[0181] The following table shows preferred embodiments of compound HTM-2:

[0182]

[0183]

[0184]

[0185]

[0186]

[0187] The second hole-transport layer preferably directly adjoins the light-emitting layer on the anode side. It is also preferred that it directly adjoins the first hole-transport layer on the cathode side.

[0188] The thickness of the second hole transport layer is preferably 2 nm to 100 nm, more preferably 5 nm to 40 nm.

[0189] The second hole transport layer preferably contains a compound of formula (I-1-B), (I-1-D), (II-1-B) or (II-1-D) as defined above, more preferably a compound of formula (I-1-D) or (II-1-D). In an alternative preferred embodiment, the second hole transport layer contains a compound of formula (III)

[0190]

[0191]

[0192] in:

[0193] Y is the same or different at each occurrence and is selected from O, S and NR 1 ;

[0194] Ar 3 is the same or different at each occurrence and is selected from phenyl, biphenyl and terphenyl, each of which is replaced by R 1 group substitution;

[0195] k is 1, 2, or 3;

[0196] i is the same or different at each occurrence and is selected from 0, 1, 2, and 3;

[0197] and wherein each of the formulas is replaced at an unoccupied position by R 1 Group substitution.

[0198] Preferably, in formula (III), Y is identical or different at each occurrence and is selected from O and S, more preferably O. Further preferably, k is 1 or 2. Also preferably, i is identical or different at each occurrence and is selected from 1 and 2, more preferably 1.

[0199] Preferably, the second hole transport layer consists of a single compound.

[0200] In addition to the cathode, anode, light-emitting layer, the first hole transport layer and the second hole transport layer, the electronic device preferably further comprises other layers. These layers are preferably selected from one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, electron blocking 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 have 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 arranged between the light-emitting layer and the anode. More preferably, the electronic device sequentially comprises one or more electron transport layers, preferably a single electron transport layer and a single electron injection layer, between the light-emitting layer and the cathode, wherein the electron injection layer mentioned is preferably directly adjacent to the cathode.

[0201] It is particularly preferred that the electronic device comprises a hole injection layer directly adjacent to the anode between the anode and the first hole transport layer. The hole injection layer preferably comprises a hexaazaterphenylidene derivative, as described in US 2007 / 0092755, or other highly electron-deficient and / or Lewis-acidic compounds, 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 compound D-13 described above.

[0202] In an alternative preferred embodiment, the hole injection layer contains a mixture of the aforementioned p-type dopant and a hole-transport material. 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 class of hole-transport materials known to those skilled in the art for OLEDs, in particular triarylamines.

[0203] The layer sequence in the electronic device is preferably as follows:

[0204] -anode-

[0205] -Hole injection layer-

[0206] -First hole transport layer-

[0207] -Optional additional hole transport layer-

[0208] -Second hole transport layer-

[0209] -Luminescent layer-

[0210] -Optional hole blocking layer-

[0211] -Electron transport layer-

[0212] -Electron injection layer-

[0213] -cathode-.

[0214] The materials for the hole injection layer and the optionally present further hole transport layer are preferably selected from the following: indenofluorenamine derivatives, amine derivatives, hexaazaterphenylidene derivatives, amine derivatives with fused aromatic systems, monobenzoindenofluorenamine, dibenzoindenofluorenamine, spirodifluorenamine, fluorenamine, spirodibenzopyranamine, dihydroacridine derivatives, spirodibenzofuran and spirodibenzothiophene, phenanthryldiarylamine, spirotribenzotropolone, spirobifluorene with m-phenyldiamine groups, spirobiacridine, xanthenediarylamine, and 9,10-dihydroanthracene spiro compounds with diarylamino groups.

[0215] The following table shows preferred specific compounds for the hole injection layer and any further hole transport layer:

[0216]

[0217]

[0218]

[0219]

[0220]

[0221] 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, phosphodiazoline derivatives, and phosphine oxide derivatives. The following table shows examples of specific compounds used in these layers:

[0222]

[0223]

[0224]

[0225] 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 -5 mbar, 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.

[0226] 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).

[0227] Furthermore, preferred are electronic devices 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 achieved by appropriate substitution of the compounds.

[0228] Preference is also given to producing 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.

[0229] After the layers have been applied (depending on the application), the component is structured, contact connections are provided, and finally sealed to exclude the damaging effects of water and air.

[0230] 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

[0231] 1) General OLED manufacturing methods and OLED characterization

[0232] Glass plates coated with structured ITO (indium tin oxide) with a thickness of 50 nm served as substrates for the application of the OLEDs.

[0233] An OLED essentially has the following layer structure: substrate / hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) / emitting layer (EML) / electron transport layer (ETL) / electron injection layer (EIL), and finally a cathode. The cathode is formed by a 100nm thick aluminum layer. The exact structure of an OLED can be found in Table 1.

[0234] All materials are applied by thermal vapor deposition in a vacuum chamber. In this example, the light-emitting layer consists of a matrix material (host material) and a luminescent dopant (emitter), which is added to the matrix material by co-evaporation in a specific volume ratio. A specification such as SMB1:SEB1 (3%) means that the material SMB1 is present in the layer at a volume ratio of 97% and the material SEB1 at a volume ratio of 3%. Similarly, the electron transport layer and, in the examples of this application, the HTL also consist of a mixture of two materials, with the material ratios reported as specified above.

[0235] The chemical structures of the materials used for OLEDs are shown in Table 2.

[0236] The OLEDs were characterized in a standard manner. For this purpose, the electroluminescence spectrum, operating voltage and lifetime were determined. The parameter U@10mA / cm 2 Refers to 10mA / cm 2 The lifetime LT is defined as the time until the luminance drops to a specified percentage from the initial luminance during operation at a constant current density. The LT80 figure here means that the reported lifetime corresponds to the time until the luminance drops to 80% of its initial value. Figures @ 60mA / cm 2 Here it means that the lifetime in question is at 60 mA / cm 2 Measured below.

[0237] 2) OLEDs of Comparative Examples Using a Mixture of Two Different Materials in HTL and Using a Single Material in HTL

[0238] In each case, an OLED was produced which contained a mixture of two different materials in the HTL and a comparative OLED which contained a single material in the HTL; see the table below:

[0239]

[0240]

[0241] In a comparison of OLEDs E1 and E2 with OLED V1 containing pure material HTM1 in the HTL, the addition of material HTM2 (E1) or HTM4 (E2) leads to a clear improvement in the lifetime, while the operating voltage remains essentially unchanged.

[0242] In a comparison of OLEDs E3, E4 and E5 with OLED V2 containing pure material HTM1 in the HTL, the addition of materials HTM2 (E3) or HTM4 (E4) or HTM8 (E5) leads to a clear improvement in the lifetime, while the operating voltage remains essentially unchanged.

[0243] The same applies to the comparison of E6, E7 and E8 with V3, and E9, E10 and E11 with V4.

[0244] The four test series differed in the material in the EBL (HTM2, HTM4, HTM8 or HTM9). This shows that the lifetime improvement effect occurs across a wide range of applications when different materials are used in the EBL.

[0245]

[0246]

[0247]

[0248]

[0249] 3) Determination of HOMO of compounds used in mixed HTL

[0250] The method described on page 28, line 1 to page 29, line 21 of the published specification WO 2011 / 032624 gives the following HOMO values ​​for the compounds HTM1, HTM2, HTM4 and HTM8:

[0251] Compound HOMO(eV) HTM1 -5.15 HTM2 -5.18 HTM4 -5.26 HTM8 -5.25

Claims

1. An electronic device comprising -anode, -cathode, - a light-emitting layer arranged between the anode and the cathode, a first hole transport layer arranged between the anode and the light-emitting layer, said first hole transport layer comprising two different compounds conforming to the same or different formulae selected from formulae (I) and (II) in Z is the same or different at 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 group 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 , 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 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 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; 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 , 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 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 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 are the same or different at each occurrence and are 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 one another 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; n is 0, 1, 2, 3 or 4, wherein, When n=0, the Ar 1 The group is absent and the nitrogen atom is directly bonded to the remainder of the formula; wherein one of the two different compounds in the first hole transport layer is compound HTM-1 and the other of the two different compounds in the first hole transport layer is compound HTM-2, wherein 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, and the HOMO of HTM-1 is 0.02 eV to 0.3 eV higher than that of HTM-2; wherein the thickness of the first hole transport layer is 30 nm to 300 nm; as well as - a second hole transport layer arranged between the first hole transport layer and the light emitting layer.

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 green or red phosphorescence.

3. The electronic device according to claim 1 or 2, characterized in that The first hole transport layer has a thickness of 30 nm to 250 nm.

4. The electronic device according to claim 1 or 2, characterized in that The first hole transport layer has a thickness of no greater than 250 nm.

5. The electronic device according to claim 1 or 2, characterized in that The first hole transport layer contains exactly two different compounds conforming to the same or different formulae selected from formulae (I) and (II).

6. The electronic device according to claim 1 or 2, characterized in that The first hole transport layer is composed of a compound that conforms to the same or different formula selected from formula (I) and (II).

7. The electronic device according to claim 1 or 2, characterized in that The first hole transport layer contains two different compounds conforming to formula (I).

8. The electronic device according to claim 1 or 2, characterized in that The two different compounds, which correspond to the same or different formulae selected from the group consisting of formulae (I) and (II), are each present in the first hole transport layer in a proportion of at least 5%.

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

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

11. The electronic device according to claim 9, characterized in that HTM-1 is present in the layer at a ratio of 65% to 85%, and HTM-2 is present in the layer at a ratio of 15% to 35%.

12. The electronic device according to claim 1 or 2, characterized in that The second hole transport layer directly adjoins the light-emitting layer on the anode side and directly adjoins the first hole transport layer on the cathode side.

13. The electronic device according to claim 1 or 2, characterized in that The second hole transport layer contains a compound of formula (I-1-B), (I-1-D), (II-1-B) or (II-1-D) wherein the groups appearing in formulae (I-1-B), (I-1-D), (II-1-B) and (II-1-D) are as defined in claim 1, and wherein the unoccupied positions on the spirobifluorene and fluorene are each replaced by R 1 group substituted, or characterized in that The second hole transport layer contains a compound of formula (III) in Y is the same or different at each occurrence and is selected from O, S and NR 1 ; Ar 3 is the same or different at each occurrence and is selected from phenyl, biphenyl and terphenyl, each of which is replaced by R 1 group substitution; k is 1, 2, or 3; i is the same or different at each occurrence and is selected from 0, 1, 2, and 3; and wherein each of the formulas is replaced at an unoccupied position by R 1 Group substitution.

14. A method for manufacturing an electronic device according to any one of claims 1 to 13, characterized in that One or more layers of the device are produced from solution or by a sublimation process.

15. Use of the electronic device according to any one of claims 1 to 13 in a display, as a light source in lighting applications or as a light source in medical and / or cosmetic applications.

Images